JP7459541B2 - Image forming apparatus and medium transport control method - Google Patents

Description

The present invention relates to an image forming apparatus and a medium transport control method.

Conventionally, electrophotographic image forming devices generally use a method of transferring toner to print media using high voltage. Also known are image forming devices that install a discharging brush in the transport path to remove surface charge in order to avoid degradation of post-processing properties due to static electricity generation or electrical adhesion when stacking printed media for ejection.

Patent Document 1 also discloses an image forming device that overlaps and discharges printed media that is not turned over and printed media that is turned over, in order to prevent static electricity from adhering to the resin film.

However, according to the conventional technology, printed print media with post-print reversal and pre-printed print media without post-print reversal are ejected after being multi-fed, so if they are stacked after being ejected, the printed print media The printing surfaces of the media are alternately reversed. Therefore, the user had to rearrange the stacked print media every other sheet.

The present invention has been made in view of the above, and an object of the present invention is to prevent the print media from sticking due to static electricity when the print media are stacked after being ejected and the print surfaces of the print media are aligned.

In order to solve the above-mentioned problems and achieve the object, the present invention provides an image carrier, a transfer means for transferring a toner image on the image carrier to a print medium, a voltage application means for applying a voltage to the transfer means, a stacking means for stacking the transferred printed media, a reversing and conveying means for turning over the printed print medium, a control means for controlling the voltage application means for applying a voltage to the transfer means again without transferring a toner image to the printed print medium that has been conveyed to the transfer means via the reversing and conveying means, a counting means for counting the number of sheets of the print medium, a first conveying means for conveying the printed print medium to the stacking means via a first conveying path without turning over the printed print medium, and a reversing and conveying path and a second conveying path. and a second transport means which transports the inverted printing medium to the transfer means via a transport path, wherein the inverting transport means inverts the printed printing medium transported via the first transport path via the inverting transport path, and the control means transports the printed printing medium to the stacking means via the first transport path without inverting it for odd/even sheets, and for even/odd sheets, applies a voltage again to the printed printing medium transported to the transfer means via the inverting transport path and the second transport path without transferring the toner image, and then inverts the printing medium via the first transport path and the inverting transport path and transports it to the stacking means.

The present invention has the advantage that, when stacking, the printing surfaces of the print media are aligned and the print media can be prevented from sticking together due to static electricity.

FIG. 1 is a diagram illustrating a schematic configuration of a main part of an image forming apparatus according to a first embodiment. FIG. 2 is a block diagram schematically showing the hardware configuration of the image forming apparatus. FIG. 3 is a simplified diagram showing the main part of a secondary transfer unit in the image forming apparatus. FIG. 4 is a diagram showing an example of print media sticking to each other due to charging. FIG. 5 is a functional block diagram showing an example of functions related to medium conveyance control processing of the image forming apparatus. FIG. 6 is a flowchart showing the flow of medium conveyance control processing of the image forming apparatus. FIG. 7 is a diagram showing an example of a stack of printed media. FIG. 8 is a flowchart showing the flow of the paper processing operation of the image forming apparatus according to the second embodiment. FIG. 9 is a diagram showing an example of a stack of printed media. FIG. 10 is a modification of the flowchart showing the flow of paper processing operations of the image forming apparatus according to the second embodiment. FIG. 11 is a diagram showing an example of a stack of printed media.

Embodiments of an image forming apparatus and a medium conveyance control method will be described in detail below with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a diagram schematically showing the configuration of main parts of an image forming apparatus 100 according to the first embodiment. In FIG. 1, an image forming apparatus 100 is an image forming apparatus generally referred to as a multifunction peripheral (MFP) that has at least two of a copy function, a printer function, a scanner function, and a facsimile function.

In this embodiment, we will explain a device that transfers a toner image developed on a photoreceptor to an intermediate transfer belt, and then performs a secondary transfer from the intermediate transfer belt to paper, film, etc., but it goes without saying that the present invention can also produce the same effects in a device that does not have an intermediate transfer body and directly transfers the toner on the photoreceptor to paper, resin film, etc.

As shown in FIG. 1, the image forming apparatus 100 has a secondary transfer unit 1, which is a transfer means, a high-voltage power source 2, a fixing unit 3, an image forming unit 4, a first conveying means 5, a stacking means 6, a second conveying means 7, and a reverse conveying means 8.

The image forming section 4 includes a tandem type image forming unit (yellow (Y), magenta (M), cyan (C), black (Bk)) 41, an intermediate transfer belt 42 which is an image carrier, and the like. Through an image forming process by the image forming unit 41, the image written by the optical writing device is formed as a toner image on the intermediate transfer belt 42.

Specifically, the image forming unit (Y, M, C, Bk) 41 rotatably includes four photoreceptor drums (Y, M, C, K), and a charging roller is placed around each photoreceptor drum. , a developing device, a primary transfer roller, a cleaner unit, and a static eliminator.

An image forming element functions on each photoreceptor drum, and the image on the photoreceptor drum is transferred onto the intermediate transfer belt 42 by each primary transfer roller. The intermediate transfer belt 42 is disposed in a nip between each photoreceptor drum and each primary transfer roller, and is stretched between a driving roller and a driven roller.

The secondary transfer section 1 includes a pair of repulsive roller R1 and a secondary transfer roller R2. The secondary transfer unit 1 transfers toner images (yellow (Y), magenta (M), cyan (C), black (Bk)) on the intermediate transfer belt 42 to the supplied printing medium P (see FIG. 3). transcribe. More specifically, the secondary transfer section 1 secondarily transfers the toner image that has been primarily transferred onto the intermediate transfer belt 42 onto the print medium P on the secondary transfer belt 11 as the intermediate transfer belt 42 runs.

The second-transferred print medium P is conveyed to the fixing section 3 by driving the first conveyance means 5, and the toner image is fixed on the print medium P as a color image. Thereafter, the print medium P is discharged to the stacking means 6 outside the machine. In the case of double-sided printing, the printing medium P is turned over by the second conveying means 7, and the turned printing medium P is sent to the secondary transfer section 1.

The stacking means 6 can be any means capable of stacking two or more media that have passed through the transfer and fixing processes, and the effects of the present invention can be obtained if two or more media are stacked.

The high voltage power supply 2 applies a voltage of the same polarity, for example, several hundred to several thousand volts, to the repulsive roller R1 of the secondary transfer section 1. The secondary transfer unit 1 transfers toner (yellow (Y), magenta (M), cyan (C), black (Bk)) on the intermediate transfer belt 42 by contact pressure and repulsion from the high voltage power source 2. The image is transferred onto the print medium P by the electric repulsion force caused by the voltage of the same polarity applied to the roller R.

The fixing unit 3 is, for example, a thermal fixing type fixing unit, and applies heat and pressure to the print medium P onto which the toner image has been transferred. This melts the toner, and the image is fixed onto the print medium P.

The first transport means 5 includes various sensors, a motor, and a roller member rotated by the motor. The first transport means 5 constitutes a first transport path leading from the secondary transfer unit 1 to the stacking means 6, and transports the printed print medium P onto which the toner image on the image carrier has been transferred in the secondary transfer unit 1 and onto which the image has been fixed in the fixing unit 3.

The stacking means 6 is equipped with various sensors, a motor, and a roller member rotated by the motor. The stacking means 6 ejects and stacks the printed print media P.

The second conveyance means 7 includes various sensors, a motor, and a roller member rotated by the motor. The second conveyance means 7 constitutes a second conveyance path from the middle of the first conveyance path to the secondary transfer section 1, and reverses the printed printing medium P with its front and back facing the conveyance direction and transfers it to the stacking means 6 again. transport.

The reversing conveyance means 8 includes various sensors, a motor, and a roller member rotated by the motor. The reversing conveyance means 8 is provided on the first conveyance path, and forms a reversal conveyance path in which the printed printing medium P conveyed through the first conveyance path is reversed and conveyed toward the stacking means 6 . In addition, since the reversing conveyance means 8 only needs to reverse the front and back sides via the reversing conveyance path, it may be reversed between B and C shown in FIG. 1 or reversed at B and conveyed to E, or reversed at C. It may also be transported to D.

Next, the hardware configuration of the image forming apparatus 100 will be described. FIG. 2 is a block diagram showing the hardware configuration of the image forming apparatus 100. As shown in FIG. 2, the image forming apparatus 100 includes a control unit 101 such as a CPU (Central Processing Unit) that controls the entire apparatus, a main memory unit 102 such as a ROM (Read Only Memory) or RAM (Random Access Memory) that stores various data and programs, an auxiliary memory unit 103 such as a HDD (Hard Disk Drive) or CD (Compact Disc) drive device that stores various data and programs, and a bus 104 that connects these, and can be realized by a hardware configuration using a normal computer.

Further, a high-voltage power supply 2 , a fixing section 3 , and an image forming section 4 are connected to the control section 101 through a bus 104 . Further, various motors constituting the first conveying means 5, the stacking means 6, the second conveying means 7, and the reversing conveying means 8 are connected to the control section 101 through a bus 104, respectively.

The program executed by the image forming device 100 of this embodiment is provided in the form of an installable or executable file recorded on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, or a DVD (Digital Versatile Disc).

The program executed by the image forming device 100 of this embodiment may be stored on a computer connected to a network such as the Internet and provided by downloading it via the network. The program executed by the image forming device 100 of this embodiment may be provided or distributed via a network such as the Internet.

The program executed by the image forming device 100 of this embodiment may also be configured to be provided by being pre-installed in a ROM or the like.

Here, FIG. 3 is a diagram simply showing the main parts of the secondary transfer section 1 in the image forming apparatus 100. In this embodiment, the toner is negatively chargeable. As shown in FIG. 3, the toner T on the intermediate transfer belt 42 due to image formation is transferred to the print medium P due to the pressure caused by contact and the electrical repulsion force caused by the negative polarity voltage applied from the high-voltage power supply G to the repulsion roller R. It is transcribed as At this time, since a voltage of several hundred to several thousand volts is applied to the repulsive roller R from the high-voltage power supply G, a minute gap discharge occurs in the transfer nip, and the front surface of the printing medium P has a negative charge, while the back surface has a negative charge. A positive charge is applied. Static electricity caused by this charging causes a "jam" in which the printing medium P wraps around a conveyance roller or the like, a stacking failure in post-processing, and paper handling failure (for example, sagging and alignment). Therefore, static electricity is generally removed by applying a separation voltage to the printing medium P immediately after the secondary transfer, or by bringing a static electricity removal brush into contact with the surface of the printing medium P after the fixing process. be exposed.

It is generally known that static electricity can be removed by applying a separation voltage immediately after secondary transfer or by rubbing the surface with a static electricity removal brush after the fixing process. When a conductive paper medium with low internal resistance is used as the print medium P, the amount of discharge itself is small and the charge is easy to move, so it is possible to remove the charge on the surface of the print medium by applying a separation voltage or using a static electricity removal brush.

On the other hand, when a high-resistance printing medium with high resistance characteristics similar to those of a dielectric is used as the printing medium P, the amount of charge itself is large and the range in which the charges can move is limited to a narrow internal area. Even if a static elimination brush is used, it is difficult to transition a high-resistance printing medium from a polarized state to a non-polarized state. Here, high resistance refers to a resistance value within the following range. For example, while the volume resistance of plain paper is 6×10 ⁸ to 9×10 ¹² Ω·cm, high resistance is 4×10 ¹³ to 5×10 ¹⁶ Ω·cm.

Note that high-resistance printing media are media that have high-resistance characteristics similar to those of dielectric materials by containing a resin component, such as coated paper, coated paper, tack paper, synthetic resin film, and laminated paper. It is a print medium.

Here, FIG. 4 is a diagram showing an example of print media sticking to each other due to charging. The print media in the polarized state described above are discharged and stacked as shown in FIG. The positive polarity (+) printing surface of the printing medium is electrically attracted to each other, resulting in the inconvenience that the printing media electrically stick to each other.

One possible solution to this problem is to use an ionizer to sprinkle ions of the opposite polarity to the charge near the surface of the print medium P, neutralizing the charge and reducing sticking. However, even if this method is adopted, although it can achieve a greater effect than using a static elimination brush, it is difficult to emit enough ions to sufficiently eliminate static electricity.

Therefore, in this embodiment, by applying voltage again using the secondary transfer unit 1 to the printed printing medium P that has been reversed, the polarities of the opposing surfaces of the overlapping printing medium P are made the same. It can be made polar and can be electrically repelled to reduce sticking. This point will be explained in detail below.

(Functional configuration and medium transport control process by program)
Next, among various types of arithmetic processing executed by the CPU of the image forming apparatus 100 in accordance with a program, a function for realizing a medium transport control process, which is a characteristic process of this embodiment, will be described below.

FIG. 5 is a functional block diagram showing an example of functions related to medium transport control processing of the image forming apparatus 100.

The CPU of the image forming apparatus 100 implements the functions of the counting means 201, the voltage applying means 202, and the controlling means 203, as shown in FIG. 5, by executing a program stored in the auxiliary storage unit 103. The counting means 201, voltage application means 202, and control means 203 will be described as being realized by software, but some or all of them may be realized by hardware such as an IC (Integrated Circuit). Good too.

Counting means 201 counts the number of print media P in a continuous job.

The voltage application means 202 uses the secondary transfer unit 1 to apply a reverse polarity voltage, which is opposite in polarity to the voltage applied by the secondary transfer unit 1, to the printed print medium P transported to the secondary transfer unit 1 by the second transport means 7.

The control means 203 controls the second conveying means 7, the voltage application means 202, and the reverse conveying means 8 for every other sheet based on the number of sheets of print media P counted by the counting means 201.

FIG. 6 is a flowchart showing the flow of medium conveyance control processing of the image forming apparatus 100. The CPU of the image forming apparatus 100 prevents the print medium P from sticking by executing the processing of this flowchart using the counting means 201, voltage application means 202, and control means 203 based on a program.

The flowchart in Figure 6 shows the operations from printing to ejection for each sheet in a continuous job of multiple sheets.

First, the counting means 201 counts the number of printed sheets in consecutive jobs (step S1). For example, in the first job, the number of printed sheets is counted as the first sheet.

Next, the control means 203 controls the first transport means 5 to transport the print medium P along the transport path A→B→E shown in FIG. 1 if it determines that the multiple-sheet continuous job is an odd-numbered sheet (No in step S2), and ejects and stacks the print medium P on the stack means 6 shown in FIG. 1 (step S7).

On the other hand, if the control means 203 determines that the multiple-sheet continuous job is an even number of sheets (Yes in step S2), it controls the first transport means 5 and the second transport means 7 to transport the print medium P along the transport path A → B → C shown in FIG. 1, invert it at C shown in FIG. 1, and transport it to the secondary transfer unit 1 via D shown in FIG. 1 (step S3). As a result, when the multiple-sheet continuous job is an even number of sheets, the print medium P is upside down when it is transported to the secondary transfer unit 1 compared to when it was fed.

Subsequently, the control unit 203 controls the voltage application unit 202 to apply a voltage (the same current in the case of constant current control) that provides the same transfer bias as during printing without printing in the secondary transfer unit 1. (Step S4). Note that in step S4, the bias voltage may be changed depending on the image area to obtain a more effective effect. Normally, in a digital machine, toner is negatively charged, so when the toner adhesion amount and image area are large, the negatively charged potential on the surface of the print medium P increases by about 20% (in absolute value) at the maximum. Therefore, it will be more effective to increase the bias voltage by up to about 20% (in absolute value) depending on the toner adhesion amount and image area. In addition, since the surface potentials of the facing surfaces of the overlapping print media P have opposite polarities but the same absolute value, the repulsion is greater. If it is small, the effect will be better if the applied bias voltage is reduced in absolute value according to the toner adhesion amount and image area.

At this point, the print medium P is facing the opposite direction from when it was fed, and opposite charges are applied to the front and back.

Then, after passing through the secondary transfer unit 1 for the second time, the control means 203 controls the first conveying means 5 and the reversing conveying means 8 to invert the print medium P at B shown in FIG. 1 (step S5), and ejects and stacks it on the stacking means 6 shown in FIG. 1 (step S6).

Here, FIG. 7 is a diagram showing an example of a stack of printed media. The example shown in FIG. 7 shows the state of static electricity in an example of a stack of print media P on which four sheets of consecutive jobs have been printed. As shown in FIG. 7, the odd-numbered printing medium P has a printing surface (front surface) of negative polarity (-) and a reverse printing surface (back surface) of positive polarity (+). On the other hand, in the even-numbered printing medium P, the printing surface (front surface) can have positive polarity (+) and the opposite printing surface (back surface) can have negative polarity (-). Therefore, when the odd-numbered print media P and the even-numbered print media P are stacked, they are stacked so that the surfaces of the same polarity face each other.

In addition, after ejection, the printed print media P are stacked with the front and back of the image still facing each other, so the image surfaces stay aligned when stacked after ejection, making it possible to prevent the print media P from sticking together due to static electricity.

That is, in the example shown in FIG. 7, the first printing medium P has a negative polarity (-) on the printing surface, and the second printing medium P stacked thereon has a negative polarity (-) on the opposite printing surface. becomes. As a result, the first print medium P and the second print medium P electrically repel each other, and sticking is prevented. Similarly, the second printing medium P has a positive polarity (+) on its printing surface, and the third printing medium P stacked thereon has a positive polarity (+) on its opposite printing surface. As a result, the second print medium P and the third print medium P electrically repel each other, and sticking is prevented. Therefore, stacking defects in post-processing and difficulty in handling are eliminated.

In this way, according to this embodiment, when the print media is discharged and stacked, the printing surfaces of the print media are aligned and the print media can be prevented from sticking together due to static electricity.

In addition, the voltage application means 202 uses a transfer means to apply the same voltage, but with the opposite polarity to the voltage applied by the transfer means, to the front and back of the printed print medium, making it possible to provide a small, inexpensive image forming device that is stable against changes over time in the transfer means and variations in lots.

In this embodiment, the first printed medium is transported along the transport path A→B→E shown in FIG. 1 and discharged and stacked on the stacking means 6, and the second printed medium passes through the secondary transfer unit 1 for the second time, is inverted by the inverting transport means 8, and is discharged and stacked on the stacking means 6, but this is not limited to the above. For example, the first printed medium may be inverted by the inverting transport means 8 and discharged and stacked on the stacking means 6 (i.e., does not pass through the second transport means 7). The second printed medium may be inverted by passing through the second transport means 7, but may be discharged and stacked on the stacking means 6 without printing (voltage is applied but toner is not applied), with only the transfer bias applied by the transfer means 1.

(Second embodiment)
Next, a second embodiment will be described.

The second embodiment differs from the first embodiment in the operation in the medium transport control process. Hereinafter, in the description of the second embodiment, description of the same parts as the first embodiment will be omitted, and only parts different from the first embodiment will be described.

The control means 203 of this embodiment controls the second conveying means 7 for all printed media P, and controls the voltage application means 202 and the reverse conveying means 8 for every other sheet of print media P based on the number of sheets of print media P counted by the counting means 201.

FIG. 8 is a flowchart showing the flow of paper processing operations of image forming apparatus 100 according to the second embodiment. The CPU 7 prevents each print medium from sticking by executing the process of this flowchart in each unit 25 to 28 based on the paper processing program.

The flowchart in Figure 8 shows the operations from printing to ejection for each sheet in a continuous job of multiple sheets.

First, the counting means 201 counts the number of printed sheets in consecutive jobs (step S11). For example, in the first job, the number of printed sheets is counted as the first sheet.

Next, when the control unit 203 determines that the continuous job of multiple sheets is an odd-numbered sheet (No in step S12), the control unit 203 controls the first conveyance unit 5 and the second conveyance unit 7 to move the print medium P, It is transported along the transport path A→B→C shown in FIG. 1, reversed at C shown in FIG. 1, and transported to the secondary transfer section 1 via D shown in FIG. 1 (step S16). As a result, when the number of consecutive sheets is an odd number in a continuous job, when the print medium P is conveyed to the secondary transfer section 1, the front and back sides are reversed from when the print medium P was fed. After that, the control means 203 controls the conveying means 5 and the reversing conveying means 8 after passing through the secondary transfer section 1 for the second time, so that the printing medium P is not turned over at B shown in FIG. The paper is discharged and stacked at E shown in (step S17). That is, for odd-numbered sheets, the secondary transfer section 1 does not print on the print medium P that has been reversed and conveyed, and no voltage is applied to the print medium P.

On the other hand, if the control unit 203 determines that the continuous job of multiple sheets is an even-numbered sheet (Yes in step S12), the control unit 203 controls the first conveyance unit 5 and the second conveyance unit 7 to move the print medium P. It is transported along the transport path A→B→C shown in FIG. 1, reversed at C shown in FIG. 1, and transported to the secondary transfer section 1 via D shown in FIG. 1 (step S13). As a result, when the number of continuous jobs is an even number of sheets, when the print medium P is conveyed to the secondary transfer section 1, the front and back sides are reversed from when the print medium P was fed.

Subsequently, the control unit 203 controls the voltage application unit 202 to apply a voltage (the same current in the case of constant current control) that provides the same transfer bias as during printing without printing in the secondary transfer unit 1. (Step S14). Note that in step S14, the bias voltage may be changed depending on the image area to obtain a more effective effect.

At this point, the print medium P is facing the opposite direction from when it was fed, and opposite charges are applied to the front and back.

Then, after passing through the secondary transfer unit 1 for the second time, the control means 203 controls the first conveying means 5 and the reversing conveying means 8 to eject and stack the print medium P onto the stacking means 6 shown in FIG. 1 without reversing it at B shown in FIG. 1 (step S15).

Here, FIG. 9 is a diagram showing an example of a stack of printed media. The example shown in FIG. 9 shows the state of static electricity in an example stack of four sheets of printed print media P of consecutive jobs. As shown in FIG. 9, the print surface (front surface) of odd-numbered print media P is negative (-) and the anti-print surface (back surface) is positive (+). In contrast, the print surface (front surface) of even-numbered print media P can be positive (+) and the anti-print surface (back surface) can be negative (-). Therefore, when odd-numbered print media P and even-numbered print media P are stacked, the surfaces of the same polarity are stacked opposite each other.

That is, in the example of FIG. 9, the first printing medium P has the opposite printing surface of positive polarity (+), and the second printing medium P stacked thereon has the printing surface of positive polarity (+). becomes. As a result, the first printing medium P and the second printing medium P electrically repel each other, and sticking is prevented. Similarly, the second printing medium P has a negative polarity (-) on its opposite printing surface, and the third printing medium P stacked thereon has a negative printing surface (-). As a result, the second printing medium P and the third printing medium P electrically repel each other, and sticking is prevented. Therefore, stacking defects in post-processing and difficulty in handling are eliminated.

As described above, according to the present embodiment, it is possible to prevent the print media from sticking due to static electricity while the print surfaces of the print media are aligned when stacking discharged sheets (stacking).

In this embodiment, in step S16, the print medium P is transported along the transport path A→B→C shown in FIG. 1, and is inverted at C shown in FIG. 1, and transported to the secondary transfer unit 1 via D shown in FIG. 1, but this is not limited to this. Here, FIG. 10 is a modified flowchart showing the flow of the paper processing operation of the image forming device 100 according to the second embodiment. As shown in FIG. 10, when the control unit 203 determines that the continuous job of multiple sheets is an odd number of sheets (No in step S12), it may control the first transport unit 5 and the inverting transport unit 8 to invert the print medium P at B shown in FIG. 1 (step S16'), and discharge and stack it on the stacking unit 6 (step S17).

Here, FIG. 11 is a diagram showing an example of a stack of printed media. The example shown in FIG. 11 corresponds to the modification example shown in FIG. 10, and shows the state of static electricity in an example of a stack of print media P on which four sheets of consecutive jobs have been printed. As shown in FIG. 11, also in the modified example of FIG. 10, the first print medium P and the second print medium P electrically repel each other, and sticking is prevented. Similarly, the second printing medium P has a negative polarity (-) on its opposite printing surface, and the third printing medium P stacked thereon has a negative printing surface (-). As a result, the second printing medium P and the third printing medium P electrically repel each other, and sticking is prevented. Therefore, stacking defects in post-processing and difficulty in handling are eliminated.

In addition, the voltage application means 202 uses the transfer means to apply a voltage of the same polarity as the voltage applied by the transfer means to the front and back of the printed print medium transported to the transfer means by the reversing transport means 8, making it possible to provide a small, inexpensive image forming device that is stable against changes over time in the transfer means and variations in the lot.

In the above embodiments, an example is given in which the image forming apparatus of the present invention is applied to a multifunction device, which is an image forming apparatus having at least two functions among a copy function, a printer function, a scanner function, and a facsimile function. However, the present invention can be applied to any image forming apparatus such as a copying machine, a printer, a scanner device, a facsimile device, and the like.

1 Transfer means 5 First conveyance means 6 Stack means 7 Second conveyance means 8 Reverse conveyance means 42 Image carrier 100 Image forming apparatus 201 Count means 202 Voltage application means 203 Control means P Print medium

JP2015-67433A

Claims (7)

An image carrier;
A transfer means for transferring the toner image on the image carrier to a printing medium;
A voltage applying means for applying a voltage to the transfer means;
A stacking means for stacking the transferred print media;
A reversing conveying means for reversing the printed print medium;
a control means for controlling the voltage application means to apply a voltage to the transfer means again without transferring a toner image to the printed print medium that has been transported to the transfer means via the reverse transport means;
A counting means for counting the number of sheets of the print medium;
a first conveying means for conveying the printed print medium to the stacking means via a first conveying path without turning the printed print medium over;
a second transport means for transporting the inverted print medium to the transfer means via a reversing transport path and a second transport path;
The reversing conveying means reverses the printed print medium conveyed through the first conveying path via the reversing conveying path,
The control means
For odd/even sheets, the printed print medium is transported to the stacking means via the first transport path without being turned over;
For even/odd sheets, the transfer is performed via the inversion transport path and the second transport path.
a voltage is applied again to the printed print medium that has been transported to the means without transferring the toner image, and then the print medium is inverted via the first transport path and the inversion transport path and transported to the stacking means . An image carrier;
a transfer means for transferring the toner image on the image carrier to a printing medium;
A voltage applying means for applying a voltage to the transfer means;
A stacking means for stacking the transferred print media;
a reversing conveyance means for reversing the printed printing medium;
A toner is applied to the printed printing medium that has been conveyed to the transfer means via the reversal conveyance means.
a control unit that controls the voltage application unit to apply a voltage to the transfer unit again without transferring the toner image;
A counting means for counting the number of sheets of the print medium;
a first conveyance means for conveying the printed printing medium to the stacking means via a first conveyance path without reversing the printed medium;
a second conveyance means for conveying the print medium with the front and back sides reversed to the transfer means via a reversal conveyance path and a second conveyance path;
The reversing conveying means reverses the printed print medium conveyed through the first conveying path via the reversing conveying path,
The control means includes:
For the odd/even numbered sheets, the printed printing medium is reversed and transported to the stacking means via the first transport path and the reversing transport path without passing through the second transport path,
For even/odd numbered sheets, the transfer is performed via the reversal conveyance path and the second conveyance path.
a voltage is applied again to the printed print medium that has been transported to the means without transferring the toner image, and then the printed print medium is transported to the stacking means via the first transport path without being inverted. An image carrier;
a transfer means for transferring the toner image on the image carrier to a printing medium;
A voltage applying means for applying a voltage to the transfer means;
A stacking means for stacking the transferred print media;
A reversing conveying means for reversing the printed print medium;
A transfer unit is provided for transferring the printed medium to the transfer unit via the reverse transfer unit.
a control unit that controls the voltage application unit to apply a voltage to the transfer unit again without transferring the toner image;
a counting means for counting the number of print media;
a first conveying means for conveying the printed print medium to the stacking means via a first conveying path without turning the printed print medium over;
a second conveyance means for conveying the print medium with the front and back sides reversed to the transfer means via a reversal conveyance path and a second conveyance path;
The reversing conveying means reverses the printed print medium conveyed through the first conveying path via the reversing conveying path,
The control means
For the odd/even numbered sheets, the transfer is performed via the reversal conveyance path and the second conveyance path.
The printed printing medium conveyed to the means is conveyed to the stacking means via the first conveyance path without transferring the toner image and without reapplying a voltage to the printed medium without turning it inside out. death,
For even/odd numbered sheets, the transfer is performed via the reversal conveyance path and the second conveyance path.
After applying a voltage again to the printed printing medium conveyed to the means without transferring the toner image, the medium is conveyed to the stacking means via the first conveyance path without being turned over. An image forming apparatus characterized by: The printing medium has a resistance value of 4×10 ¹³ ～5×10 ¹⁶ 4. The image forming apparatus according to claim 1, wherein the medium has a high resistance of Ω·cm. The printing medium includes coated paper, coated paper, tack paper, synthetic resin film, and laminated paper.
The image forming apparatus according to claim 4, wherein the image forming apparatus is one of the two. An image carrier, a transfer means for transferring a toner image on the image carrier to a printing medium,
A voltage application means for applying a voltage to the step, a stacking means for stacking the print media on which the transferred print has been made, and a reversing and conveying means for reversing the print media on which the printed print has been made;
The printed medium is conveyed to the transfer means via the inverting conveying means.
a control means for controlling the voltage application means to apply a voltage again to the transfer means without transferring the toner image;
a counting means for counting the number of print media;
a first conveying means for conveying the printed print medium to the stacking means via a first conveying path without turning the printed print medium over;
a second conveyance means for conveying the print medium with the front and back sides reversed to the transfer means via a reversal conveyance path and a second conveyance path;
A medium transport control method in an image forming apparatus comprising:
The inverting and conveying means inverts the printed print medium conveyed through the first conveying path via the inverting and conveying path;
The control means
Concerning the odd/even numbered sheets, the method includes a step of transporting the printed printing medium to the stacking means without reversing the front and back sides via the first transport path,
For even/odd numbered sheets, the transfer is performed via the reversal conveyance path and the second conveyance path.
After applying voltage again to the printed printing medium conveyed by the means without transferring the toner image, the printing medium is reversed via the first conveyance path and the reversal conveyance path. A method for controlling medium conveyance, comprising the step of conveying the medium to the stacking means. an image carrier, a transfer means for transferring a toner image on the image carrier to a print medium, a voltage application means for applying a voltage to the transfer means, a stacking means for stacking the transferred and printed print medium, and a reversing and conveying means for reversing the printed print medium from front to back;
The printed medium is conveyed to the transfer means via the inverting conveying means.
a control means for controlling the voltage application means to apply a voltage to the transfer means again without transferring a toner image;
A counting means for counting the number of sheets of the print medium;
a first conveying means for conveying the printed print medium to the stacking means via a first conveying path without turning the printed print medium over;
a second conveying means for conveying the inverted print medium to the transfer means via a reversing conveying path and a second conveying path;
A medium transport control method in an image forming apparatus comprising:
The inverting and conveying means inverts the printed print medium conveyed through the first conveying path via the inverting and conveying path ,
The control means
a step of inverting the printed print medium via the first transport path and the inverting transport path without passing through the second transport path and transporting the printed print medium to the stacking means for odd/even sheets,
For even/odd sheets, the transfer is performed via the inversion transport path and the second transport path.
a step of applying a voltage again to the printed print medium that has been transported to the means without transferring the toner image, and then transporting the printed print medium to the stacking means via the first transport path without inverting it.

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