JP2021018393A - Image forming apparatus - Google Patents

Abstract

To appropriately perform conveyance of continuous form paper before the start of warm-up of a fixing unit not according to a user's discretion.SOLUTION: An image forming apparatus 1 comprises: a paper conveying unit 50 that conveys continuous form paper; and a control unit 80 that determines whether the posture of the continuous form paper conveyed by the paper conveying unit 50 becomes stable, and when determining that the posture of the continuous form paper becomes stable, starts warming-up of a fixing unit 60.SELECTED DRAWING: Figure 4

Description

The present invention relates to an image forming apparatus.

Conventionally, in an electrophotographic image forming apparatus, an electrostatic latent image is formed on the surface of a photosensitive drum by irradiating a uniformly charged photosensitive drum with a laser beam based on image information. Then, by supplying toner to the photosensitive drum on which the electrostatic latent image is formed, the electrostatic latent image is visualized and the toner image is formed. After this toner image is transferred to the paper by the nip portion formed between the intermediate transfer belt and the secondary transfer roller, the toner image is fixed to the paper by heating and pressurizing at the fixing portion, and the paper is fixed. An image is formed in.

Further, as a fixing method by the fixing portion, a heating roller having a heating source, an upper pressure roller, and a lower pressure roller are provided, and a fixing belt is suspended on the heating roller and the upper pressure roller to heat the paper. The heat generated by the heating source is transferred to the paper via the rollers and the fixing belt to heat the paper, and the paper is heated by forming a nip between the fixing belt and the lower pressure roller by the pressurization of the upper pressure roller. Is known as a method of pressurizing. The heat generated by the heating source is first transmitted to the fixing belt and then to the lower pressure roller via the fixing belt, and the paper is heated by the heat of the fixing belt and the heat of the lower pressure roller. .. Compared with the fixing method that does not use the fixing belt (the method in which the heating roller contacts the paper to heat and pressurize), the fixing method using such a fixing belt warms up the fixing part (toner image on the paper). There are advantages that the time required for (raising the temperature of the fixing member to a temperature at which fixing is possible) and the power consumption for warming up the fixing portion are small.

By the way, in the image forming apparatus, continuous paper (continuous paper) such as roll paper or continuous form that is longer than the length of the apparatus main body (that is, longer than the paper passing path portion provided from the feeding portion to the paper ejection portion of the apparatus main body) May be used as paper. When the user gives an instruction to stop image formation during image formation, or when error processing is performed for some reason to stop image formation, paper that is not continuous paper (for example, A4 size paper) is used as paper. In the image forming apparatus used, the image formation can be stopped after the paper is ejected from the paper ejection portion, or the paper can be stopped on the upstream side of the fixing portion of the paper path portion, whereas the continuous paper can be stopped. Since this cannot be done with the image forming apparatus used as paper, the continuous paper is stopped from being conveyed while the continuous paper remains in the fixing portion. If the continuous paper is removed from the apparatus main body when the image formation is stopped, the continuous paper does not stagnate in the fixing portion, but it takes time and effort to remove the continuous paper from the apparatus main body and pass the paper again.

In this way, when the image formation is stopped, if the continuous paper is left while being sandwiched between the nip portions formed by the fixing belt and the lower pressure roller, when the image formation is stopped, it is sent to the heating source. Although the power supply is stopped to lower the temperature of the fixing part, the heat of the fixing part causes damage such as deformation and discoloration of the continuous paper. Therefore, when stopping the transfer of continuous paper in a fixing method that uses heat such as a fixing belt, the fixing belt is moved from the lower pressure roller so that the continuous paper does not come into contact with the fixing belt and heat is not directly transferred to the continuous paper. It is known that the nips are released by separating them so that the continuous paper does not come into contact with the fixing belt. By preventing the continuous paper from contacting the fixing belt, the heat of the fixing part is not directly transferred to the continuous paper, but the heat is transferred to the continuous paper through the air near the fixing belt in the fixing part, so that it is continuous. Although the amount of deformation is smaller than when the paper is in contact with the fixing belt, continuous paper is deformed or the like.

On the other hand, when the image formation is restarted, the heat of the fixing portion is lowered by stopping the power supply to the heating source, so the fixing portion is warmed up (fixed temperature rise) in preparation for image formation. .. In warming up the fixing portion, when heating is performed by the heating source of the heating roller, the fixing belt is rotated in a separated state in order to make the temperature of the entire fixing belt uniform. In this case, the continuous paper may come into contact with the fixing belt due to deformation of the continuous paper or the like even though the fixing belts are separated from each other. If the fixing belt is rotated while the continuous paper is in contact with the fixing belt, there is a problem that the fixing belt is scratched in the circumferential direction due to the rubbing generated between the continuous paper and the fixing belt.

To solve such a problem, an image forming apparatus (see, for example, Patent Document 1) has been proposed in which the continuous paper is moved so that the continuous paper does not come into contact with the fixing belt when the fixing portion is warmed up. There is. Further, an image forming apparatus (see, for example, Patent Document 2) that controls the transport of continuous paper when deformation of continuous paper is detected has been proposed.

Japanese Unexamined Patent Publication No. 2016-180925 Japanese Unexamined Patent Publication No. 2016-130787

In the image forming apparatus disclosed in Patent Document 1 and Patent Document 2, image forming is started again in a situation where the posture of the continuous paper is assumed to be unstable, such as after the continuous paper is replaced or after the jam is restored. In this case, it is desirable to transport the continuous paper until the posture of the continuous paper is stable, but the transport of the continuous paper is left to the discretion of the user. For this reason, when the image formation is started, the fixing portion may be warmed up in a state where the continuous paper is not conveyed, and in such a case, the continuous paper is warmed up due to the warming up of the fixing portion. Problems such as misalignment of seams may occur, which may hinder paper transport during image formation.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus capable of appropriately transporting continuous paper before starting warming up of a fixing portion without leaving it to the discretion of the user. And.

In order to solve the above problems, the image forming apparatus according to claim 1 is
An image forming apparatus including a fixing portion for passing a continuous paper on which an unfixed toner image is formed through a fixing nip and fixing the unfixed toner image to the continuous paper.
A transport unit that transports the continuous paper and
A control unit that determines whether or not the posture of the continuous paper conveyed by the transport unit is stable, and if it is determined that the posture of the continuous paper is stable, starts warming up the fixing unit.
It is characterized by having.

The invention according to claim 2 is the image forming apparatus according to claim 1.
A tension applying mechanism for applying tension to the continuous paper is provided.
The control unit is characterized in that when a tension of a predetermined magnitude is applied to the continuous paper by the tension applying mechanism, warming up of the fixing unit is started.

The invention according to claim 3 is the image forming apparatus according to claim 2.
The control unit is characterized in that when the tension applied by the tension applying mechanism becomes smaller than the predetermined magnitude, warming up of the fixing unit is stopped.

The invention according to claim 4 is the image forming apparatus according to any one of claims 1 to 3.
The control unit controls the transport of the continuous paper by the transport unit, determines the transport speed of the continuous paper when determining whether or not the posture of the continuous paper is stable, and sets the unfixed toner image as the continuous. It is characterized in that it is slower than the transport speed of the continuous paper when it is fixed on the paper.

The invention according to claim 5 is the image forming apparatus according to claim 4.
A reception unit for receiving an instruction operation for instructing the start of warming up of the fixing unit is provided.
When the instruction operation is received by the receiving unit, the control unit starts transporting the continuous paper by the transporting unit, and determines whether or not the posture of the continuous paper transported by the transporting unit is stable. When the determination is made and it is determined that the posture of the continuous paper is stable, warming up of the fixing portion is started.

The invention according to claim 6 is the image forming apparatus according to any one of claims 1 to 5.
A detection unit for detecting meandering of the continuous paper transported by the transport unit is provided.
The control unit determines whether or not the meandering of the continuous paper has converged based on the detection result of the meandering of the continuous paper by the detection unit, and when it is determined that the meandering of the continuous paper has converged, the continuous paper It is characterized in that it is determined that the posture of the paper is stable.

The invention according to claim 7 is the image forming apparatus according to any one of claims 1 to 5.
A measuring unit for measuring the transport distance of the continuous paper transported by the transport unit is provided.
The control unit determines whether or not the transport distance of the continuous paper has reached a predetermined distance based on the measurement result of the transport distance of the continuous paper by the measurement unit, and the transport distance of the continuous paper is predetermined. When it is determined that the distance has been reached, it is determined that the posture of the continuous paper is stable.

The invention according to claim 8 is the image forming apparatus according to any one of claims 1 to 5.
A detection unit that detects meandering of the continuous paper conveyed by the transfer unit, and
A measuring unit that measures the transport distance of the continuous paper transported by the transport unit,
With
The first mode in which the determination of whether or not the posture of the continuous paper is stable is performed based on the detection result of the meandering of the continuous paper by the detection unit, and the measurement result of the transport distance of the continuous paper by the measurement unit. A second mode, which is performed based on the above, is provided in advance.
When the first mode is set, the control unit determines whether or not the meandering of the continuous paper has converged based on the detection result of the meandering of the continuous paper by the detection unit, and determines whether or not the meandering of the continuous paper has converged. When it is determined that the meandering has converged, it is determined that the posture of the continuous paper is stable, while when the second mode is set, it is based on the measurement result of the transport distance of the continuous paper by the measuring unit. , It is determined whether or not the transport distance of the continuous paper has reached a predetermined distance, and when it is determined that the transport distance of the continuous paper has reached a predetermined distance, it is determined that the posture of the continuous paper is stable. It is characterized by that.

The invention according to claim 9 is the image forming apparatus according to claim 7 or 8.
The predetermined distance is, at least, a distance from a predetermined working position where the work of joining the continuous papers is performed until the continuous paper passes through the fixing portion.

According to the present invention, the continuous paper before the start of warming up of the fixing portion can be appropriately conveyed without leaving it to the discretion of the user.

It is a figure which shows the image forming apparatus which concerns on embodiment of this invention. It is a figure which shows the structure of the apparatus main body. It is a block diagram for demonstrating the control of an image forming apparatus. It is a flowchart which shows the procedure of the fixing warm-up process.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an image forming apparatus 1 according to an embodiment of the present invention. The image forming apparatus 1 includes a paper feeding device 1A, an apparatus main body 1B, and a winding device 1C. The image forming apparatus 1 may be configured only by the apparatus main body 1B without providing the paper feeding device 1A and the winding device 1C.

The paper feeding device 1A accommodates continuous paper such as roll paper and continuous forms, and feeds continuous paper to the device main body 1B. Further, the paper feeding device 1A includes a tension applying mechanism 1A1. The tension applying mechanism 1A1 applies a predetermined amount of tension to the continuous paper fed to the apparatus main body 1B.

The apparatus main body 1B forms an image on continuous paper fed from the paper feeding device 1A. The take-up device 1C winds up the continuous paper sent out by the device main body 1B according to the instruction from the device main body 1B.

FIG. 2 is a diagram showing a configuration example of the device main body 1B. FIG. 3 is a block diagram showing a main part of the control system of the apparatus main body 1B.

The apparatus main body 1B shown in FIGS. 2 and 3 is an intermediate transfer type color image forming apparatus using electrophotographic process technology. In the device main body 1B, photosensitive drums 413 corresponding to four colors of Y (yellow), M (magenta), C (cyan), and K (black) are arranged in series in the traveling direction (vertical direction) of the intermediate transfer belt 421. , A vertical tandem system is adopted in which the toner images of each color are sequentially transferred to the intermediate transfer belt 421. That is, the apparatus main body 1B primary transfers each color toner image of YMCK formed on the photosensitive drum 413 to the intermediate transfer belt 421, superimposes the four color toner images on the intermediate transfer belt 421, and then forms the continuous paper. An image is formed by secondary transfer.

As shown in FIGS. 2 and 3, the apparatus main body 1B includes an operation display unit 20, an image processing unit 30, an image forming unit 40, a paper transport unit 50, a fixing unit 60, and a control unit 80.

The control unit 80 includes a CPU 81, a ROM 82, a RAM 83, and the like. The CPU 81 reads a program according to the processing content from the ROM 82 or the storage unit 72, develops it in the RAM 83, and controls the operations of the paper feeding device 1A, the device main body 1B, and the winding device 1C in cooperation with the expanded program. ..

The communication unit 71 has various interfaces such as a network card, a modem, and USB. The storage unit 72 is composed of, for example, a non-volatile semiconductor memory (so-called flash memory) or a hard disk drive. The storage unit 72 stores, for example, a lookup table that is referred to when controlling the operation of each block.

The control unit 80 transmits and receives various data to and from an external device (for example, a personal computer) connected to a communication network such as a LAN or WAN via the communication unit 71. The control unit 80 receives, for example, image data (input image data) in a page description language (PDL) transmitted from an external device, and forms an image on continuous paper based on the image data (input image data). Further, the control unit 80 transmits / receives various data to / from the paper feeding device 1A and the winding device 1C via the communication unit 71.

The operation display unit 20 is composed of, for example, a liquid crystal display (LCD) with a touch panel, and functions as a display unit 21 and an operation unit 22.

The display unit 21 displays various operation screens, operation status of each function, and the like according to the display control signal input from the control unit 80. Further, it receives a touch operation by the user and outputs an operation signal to the control unit 80.

The operation unit 22 includes various operation keys such as a numeric keypad and a start key, receives various input operations by the user, and outputs an operation signal to the control unit 80. The user can operate the operation display unit 20 to perform setting related to image formation such as image quality setting, magnification setting, application setting, output setting, and paper setting, and paper transport instruction.

The image processing unit 30 includes a circuit or the like that performs digital image processing according to initial settings or user settings on the input image data. For example, the image processing unit 30 performs gradation correction based on the gradation correction data (gradation correction table) under the control of the control unit 80. Further, the image processing unit 30 performs various correction processes such as color correction and shading correction, compression processing, and the like on the input image data. The image forming unit 40 is controlled based on the image data subjected to these processes.

The image forming unit 40 includes an image forming unit 41, an intermediate transfer unit 42, and the like for forming an image with each colored toner of the Y component, the M component, the C component, and the K component based on the input image data.

The image forming unit 41 is composed of four image forming units 41Y, 41M, 41C, and 41K for the Y component, the M component, the C component, and the K component. Since the image forming units 41Y, 41M, 41C, and 41K have the same configuration, they are shown by the same reference numerals below. The image forming unit 41 includes an exposure device 411, a developing device 412, a photosensitive drum 413, a charging device 414, a drum cleaning device 415, and the like.

The photosensitive drum 413 is a negatively charged type in which, for example, an undercoat layer (UCL), a charge generation layer (CGL), and a charge transport layer (CTL) are sequentially laminated on the peripheral surface of a conductive cylinder (aluminum tube) made of aluminum. Organic photoconductor (OPC). The charge generation layer is made of an organic semiconductor in which a charge generation material (for example, a phthalocyanine pigment) is dispersed in a resin binder (for example, polycarbonate), and is exposed by an exposure apparatus 411 to generate a pair of positive and negative charges. The charge transport layer is composed of a hole transporting material (electron donating nitrogen-containing compound) dispersed in a resin binder, and transports positive charges generated in the charge generation layer to the surface of the charge transport layer.

The charging device 414 is composed of a corona discharge generator such as a scorotron charging device or a corotron charging device. The charging device 414 uniformly charges the surface of the photosensitive drum 413 to a negative electrode by corona discharge.

The exposure device 411 transmits, for example, an LED array in which a plurality of light emitting diodes (LEDs) are linearly arranged, an LPH drive unit (driver IC) for driving each LED, and a synchrotron radiation drum 413 from the LED array. It is composed of an LED print head having a lens array or the like to be imaged on the top. One LED in the LED array corresponds to one dot in the image. When the control unit 80 controls the LPH drive unit, a predetermined drive current is passed through the LED array, and a specific LED emits light.

The exposure device 411 irradiates the photosensitive drum 413 with light corresponding to the image of each color component. The surface charge (negative charge) of the photosensitive drum 413 is neutralized by transporting the positive charge generated in the charge generation layer of the photosensitive drum 413 to the surface of the charge transport layer. As a result, an electrostatic latent image of each color component is formed on the surface of the photosensitive drum 413 due to the potential difference from the surroundings.

The developing device 412 contains a developing agent for each color component (for example, a two-component developing agent composed of a toner and a magnetic carrier), and an electrostatic latent image is produced by adhering the toner for each color component to the surface of the photosensitive drum 413. Visualize to form a toner image. Specifically, a development bias voltage is applied to the developer carrier (development roller), and the charged toner on the developer carrier is exposed to the exposed portion on the surface of the photosensitive drum 413 due to the potential difference between the photosensitive drum 413 and the developer carrier. Move to and stick to.

The drum cleaning device 415 has a drum cleaning blade or the like that is slidably contacted with the surface of the photosensitive drum 413, and removes transfer residual toner remaining on the surface of the photosensitive drum 413 after the primary transfer.

The intermediate transfer unit 42 includes an intermediate transfer belt 421, a primary transfer roller 422, a plurality of support rollers 423, a secondary transfer roller 424, a belt cleaning device 426, and the like.

The intermediate transfer belt 421 is composed of an endless belt, and is stretched in a loop on a plurality of support rollers 423. At least one of the plurality of support rollers 423 is composed of a driving roller, and the other is composed of a driven roller. For example, it is preferable that the support roller 423 arranged on the downstream side in the belt traveling direction with respect to the primary transfer roller 422 for the K component is the drive roller. As the drive roller rotates, the intermediate transfer belt 421 travels at a constant speed in the direction of arrow A.

The primary transfer roller 422 is arranged on the inner peripheral surface side of the intermediate transfer belt 421 so as to face the photosensitive drum 413 of each color component. When the primary transfer roller 422 is pressed against the photosensitive drum 413 with the intermediate transfer belt 421 sandwiched between them, a primary transfer nip for transferring the toner image from the photosensitive drum 413 to the intermediate transfer belt 421 is formed.

The secondary transfer roller 424 is arranged on the outer peripheral surface side of the intermediate transfer belt 421 so as to face one of the plurality of support rollers 423. The support roller 423 arranged to face the intermediate transfer belt 421 is called a backup roller. By pressing the secondary transfer roller 424 against the backup roller with the intermediate transfer belt 421 sandwiched between them, a secondary transfer nip for transferring the toner image from the intermediate transfer belt 421 to the continuous paper is formed.

When the intermediate transfer belt 421 passes through the primary transfer nip, the toner image on the photosensitive drum 413 is sequentially superimposed on the intermediate transfer belt 421 and the primary transfer is performed. Specifically, a primary transfer bias is applied to the primary transfer roller 422, and a charge having a polarity opposite to that of the toner is applied to the back surface side (the side that abuts the primary transfer roller 422) of the intermediate transfer belt 421 to obtain a toner image. It is electrostatically transferred to the intermediate transfer belt 421.

After that, when the continuous paper passes through the secondary transfer nip, the toner image on the intermediate transfer belt 421 is secondarily transferred to the continuous paper. Specifically, a toner image is obtained by applying a secondary transfer bias to the secondary transfer roller 424 and applying a charge having a polarity opposite to that of the toner on the back surface side of the continuous paper (the side that comes into contact with the secondary transfer roller 424). Is electrostatically transferred to continuous paper. The continuous paper on which the toner image is transferred is conveyed toward the fixing portion 60.

The belt cleaning device 426 has a belt cleaning blade or the like that is in sliding contact with the surface of the intermediate transfer belt 421, and removes the transfer residual toner remaining on the surface of the intermediate transfer belt 421 after the secondary transfer.

In the intermediate transfer unit 42, instead of the secondary transfer roller 424, a secondary transfer belt is stretched in a loop on a plurality of support rollers including the secondary transfer roller (belt type secondary transfer unit). ) May be adopted.

The paper transport unit 50 includes a paper feed unit 51, a paper discharge unit 52, a paper passage unit 53, a detection unit 54, and the like. The paper feeding unit 51 guides the continuous paper conveyed from the paper feeding device 1A to the paper path unit 53. The paper passing path portion 53 includes a plurality of transport rollers including an intermediate transport roller and the like. The paper passing path unit 53 conveys the continuous paper fed from the paper feeding unit 51 in the order of the image forming unit 40 (secondary transfer unit), the fixing unit 60, and the paper ejection unit 52. The paper ejection unit 52 guides the continuous paper conveyed from the paper passing path unit 53 to the winding device 1C. The detection unit 54 is arranged at a predetermined position downstream of the paper feeding unit 51 and upstream of the secondary transfer roller 424, and is at the end position in the width direction (CD direction) of the continuous paper conveyed through the paper passing path unit 53. Is detected.

The fixing portion 60 includes a heating roller 61, a heating source 61A for heating the heating roller 61, an upper pressurizing roller 62, an endless fixing belt 63 bridged between the heating roller 61 and the upper pressurizing roller 62, and a lower addition. A pressure roller 64 and the like are provided.

The heating source 61A is arranged inside or near the heating roller 61. The output of the heating source 61A is controlled by the control unit 80, and the heating roller 61 is heated. Further, by rotating the fixing belt 63, the heat of the heating roller 61 is transferred to the entire fixing belt 63. This fixing warm-up (fixing temperature raising operation) is performed with the fixing belt 63 separated from the lower pressurizing roller 64.

In the fixing portion 60, the fixing belt 63 suspended on the heating roller 61 and the upper pressurizing roller 62 and the lower pressurizing roller 64 can be crimped and separated from each other. The heating roller 61 and the upper pressurizing roller 62 are movably held by a holding body (not shown), and an eccentric cam (not shown) is in contact with the holding body. The eccentric cam rotates around its fulcrum, and the holding body moves in the vertical direction (crimp separation direction) due to the rotation of the eccentric cam. The heating roller 61 and the upper pressurizing roller 62 move with the movement of the holding body, whereby the fixing belt 63 can be crimped and separated from the lower pressurizing roller 64. The eccentric cam is rotated by being driven by a drive unit (motor or gear) (not shown). The drive unit is driven by the instruction of the control unit 80.

When the fixing belt 63 is pressed against the lower pressure roller 64, a nip portion for narrowly holding and transporting the continuous paper is formed. The continuous paper is heated and pressurized as it passes through the nip, and the toner image is fixed.

Next, the operation of the image forming apparatus 1 according to the present embodiment will be described with reference to FIG. FIG. 4 is a flowchart showing a procedure for fixing and warming up the image forming apparatus 1 according to the present embodiment.

As shown in FIG. 4, the control unit 80 determines whether or not the fixing warm-up start button (not shown) displayed on the display unit 21 has been pressed (step S1).

When it is determined in step S1 that the pressing operation of the fixing warm-up start button has been performed (step S1; YES), the control unit 80 sets the transport speed when continuously transporting the continuous paper by the paper transport unit 50 (step S1; YES). S2). The transport speed set in step S2 is set to a speed slower than the transport speed of the continuous paper at the time of printing, that is, when the unfixed toner image is fixed on the continuous paper. This is because if the transport speed is too high, paper breakage may occur when the adhesiveness of the joints of continuous paper is incomplete.

Next, the control unit 80 determines whether or not the first mode has been set (step S3). Here, the first mode is a mode in which when the continuous paper is conveyed by the paper conveying unit 50, the continuous paper is conveyed until the meandering of the continuous paper converges. In addition to the first mode, a second mode is provided in advance. The second mode is a mode in which the continuous paper is conveyed until the conveying distance of the continuous paper reaches a predetermined distance. The setting of the first mode or the second mode shall be performed via the operation unit 22.

If it is determined in step S3 that the first mode has been set (step S3; YES), the control unit 80 starts conveying continuous paper at the conveying speed set in step S2 (step S4). ).

Next, the control unit 80 determines whether or not the meandering of the continuous paper has converged (step S5). Specifically, the control unit 80 is in a state where the end position is within a preset range based on the end position in the width direction (CD direction) of the continuous paper detected by the detection unit 54. When the duration of is reached a predetermined time, it is determined that the meandering of the continuous paper has converged.

If it is determined in step S5 that the meandering of the continuous paper has not converged (step S5; NO), the control unit 80 repeats the determination process of step S5 until the meandering of the continuous paper converges.
On the other hand, when it is determined in step S5 that the meandering of the continuous paper has converged (step S5; YES), the control unit 80 determines that the posture of the continuous paper is stable, and stops the transport of the continuous paper (step S5; YES). Step S9), the process proceeds to step S10.

Further, in step S3, when it is determined that the first mode is not set, that is, the second mode is set (step S3; NO), the control unit 80 tells the continuous paper transport distance. Is set (step S6). As shown in FIGS. 1 and 2, for example, the transport distance set in step S6 is such that the continuous paper is fixed with the predetermined work position (paper joint position) P1 at which the continuous paper joining work is performed as a base point. The distance is set to reach a predetermined position P2 that has passed through the unit 60.

Next, the control unit 80 starts conveying continuous paper at the conveying speed set in step S2 (step S7).

Next, the control unit 80 determines whether or not the continuous paper has been conveyed by the conveying distance set in step S6 (step S8). Here, the control unit 80 functions as a measurement unit that measures the transfer distance of the continuous paper conveyed by the paper transfer unit 50.

In step S8, when it is determined that the continuous paper is not conveyed by the transfer distance set in step S6 (step S8; NO), the control unit 80 continues until the continuous paper is conveyed by the transfer distance. The determination process of step S8 is repeated.
On the other hand, in step S8, when it is determined that the continuous paper has been conveyed by the conveying distance set in step S6 (step S8; YES), the control unit 80 determines that the posture of the continuous paper is stable, and the continuous paper is determined. (Step S9), and the process proceeds to step S10.

Next, the tension applying mechanism 1A1 applies a predetermined amount of tension to the continuous paper fed to the apparatus main body 1B under the control of the control unit 80 (step S10).

Next, the control unit 80 determines whether or not the continuous paper is in a state in which a predetermined amount of tension is applied (tension application state) based on the height position of the dancer roller 1A11 of the tension application mechanism 1A1. (Step S11).

When it is determined in step S11 that the continuous paper is in a state in which a predetermined amount of tension is applied (step S11; YES), the control unit 80 starts warming up the fixing unit 60 (step S12). ).

Next, the control unit 80 determines whether or not a print instruction has been given (step S13). Here, the print instruction includes, for example, an instruction based on the operation of pressing the print start button (not shown) displayed on the display unit 21, or an external device (for example,) connected to the communication network via the communication unit 71. There are printing instructions from a personal computer).

If it is determined in step S13 that the print instruction has not been given (step S13; NO), the control unit 80 returns the process to step S11 and repeats the subsequent processes.
On the other hand, when it is determined in step S13 that the printing instruction has been given (step S13; YES), the control unit 80 determines that the fixing unit 80 has reached a temperature at which the toner image can be fixed on the continuous paper, and then the fixing unit 80. The warm-up of 60 is completed (step S14).

Next, the control unit 80 starts printing (step S15) and ends the fixing warm-up process.

Further, in step S11, when it is determined that the tension is not applied, that is, the continuous paper is not applied with a predetermined amount of tension (step S11; NO), the control unit 80 warms up the fixing unit 60. Is stopped (step S16), and the fixing warm-up process is completed.

If it is determined in step S1 that the fixing warm-up start button has not been pressed (step S1; NO), the control unit 80 determines whether or not a print instruction has been given (step S17).

If it is determined in step S17 that the print instruction has not been given (step S17; NO), the control unit 80 returns the process to step S1 and repeats the subsequent processes.
On the other hand, if it is determined in step S17 that the print instruction has been given (step S17; YES), the control unit 80 starts warming up the fixing unit 60 (step S18), and proceeds to the process in step S14.

As described above, according to the image forming apparatus 1 according to the present embodiment, whether or not the postures of the paper transport unit (conveyor unit) 50 for transporting the continuous paper and the continuous paper conveyed by the paper transport unit 50 are stable. When it is determined that the posture of the continuous paper is stable, the control unit 80 for starting the warm-up of the fixing unit 60 is provided, so that the continuous paper before the start of warming up of the fixing unit 60 can be conveyed. , Can be done properly without leaving it to the discretion of the user.

Further, according to the image forming apparatus 1 according to the present embodiment, the tension applying mechanism 1A1 for applying tension to the continuous paper is provided, and the control unit 80 applies tension of a predetermined magnitude to the continuous paper by the tension applying mechanism 1A1. If this is the case, the fixing unit 60 is warmed up, so that problems such as loose continuous paper coming into contact with the fixing belt 63 when the fixing unit 60 is warmed up can be suppressed, and the fixing unit 60 can be warmed up. The machine can be run smoothly.

Further, according to the image forming apparatus 1 according to the present embodiment, the control unit 80 stops warming up the fixing unit 60 when the tension applied by the tension applying mechanism 1A1 becomes smaller than a predetermined magnitude. Therefore, when a problem such as looseness of the continuous paper or a piece of paper occurs, the warming up of the fixing unit 60 is stopped, so that the problem such as the continuous paper coming into contact with the fixing belt 63 can be suppressed.

Further, according to the image forming apparatus 1 according to the present embodiment, the control unit 80 controls the transport of continuous paper by the paper transport unit 50, and determines whether or not the posture of the continuous paper is stable. Since the paper transport speed is slower than the transport speed of the continuous paper when the unfixed toner image is fixed on the continuous paper (during printing), the paper runs out when determining whether the posture of the continuous paper is stable. Can be suppressed from occurring.

Further, according to the image forming apparatus 1 according to the present embodiment, the control unit 80 starts the continuous paper transfer by the paper transfer unit 50 when the instruction operation for instructing the start of warming up of the fixing unit 60 is received. Then, it is determined whether or not the posture of the continuous paper conveyed by the paper transport unit 50 is stable, and when it is determined that the posture of the continuous paper is stable, the fixing unit 60 is started to warm up. The continuous paper before the start of warming up of 60 can be appropriately conveyed without leaving it to the discretion of the user, and the warming up of the fixing unit 60 can be started at a timing desired by the user.

Further, the image forming apparatus 1 according to the present embodiment has a first mode in which it is determined whether or not the posture of the continuous paper is stable based on the detection result of the meandering of the continuous paper by the detection unit 54, and the continuous paper. A second mode, which is performed based on the measurement result of the transport distance of the above, is provided in advance, and when the first mode is set, the control unit 80 determines the detection result of the meandering of continuous paper by the detection unit 54. Based on this, it is determined whether or not the meandering of the continuous paper has converged, and if it is determined that the meandering of the continuous paper has converged, it is determined that the posture of the continuous paper is stable, but when the second mode is set, it is determined. , Based on the measurement result of the continuous paper transport distance, it is determined whether or not the continuous paper transport distance has reached a predetermined distance, and when it is determined that the continuous paper transport distance has reached the predetermined distance, it is continuous. It is judged that the posture of the paper is stable.
Therefore, according to the image forming apparatus 1 according to the present embodiment, it is possible to flexibly and appropriately transport the continuous paper before the start of warming up of the fixing unit 60 without leaving it to the discretion of the user.

Further, according to the image forming apparatus 1 according to the present embodiment, the base point is at least a predetermined work position P1 at which the work of joining the continuous papers is performed at a predetermined distance which is a determination standard when the second mode is set. The distance is set as the distance until the continuous paper passes through the fixing portion 60.
Therefore, when the warm-up of the fixing portion 60 is started, it is possible to prevent the joint of the continuous paper from being present at the position corresponding to the fixing portion 60. Therefore, the heat generated by the warm-up of the fixing portion 60 causes the continuous paper to be warmed up. It is possible to prevent problems such as misalignment of joints.

The present invention has been specifically described above based on the embodiment of the present invention, but the present invention is not limited to the above embodiment and can be changed without departing from the gist thereof.

For example, in the above embodiment, either the first mode or the second mode can be set via the operation unit 22, but for example, only the first mode may be provided or the second mode. Only the mode of may be provided.

Further, in the above-described embodiment, in step S6 of the fixing warm-up process, a predetermined working position (paper joining position) P1 at which the continuous paper joining work is performed is used as a base point, and the continuous paper passes through the fixing portion 60. Although the distance to reach the position P2 is set as the transport distance, a distance longer than the distance may be set as the transport distance.

1 Image forming device 1A1 Tension applying mechanism 20 Operation display unit 30 Image processing unit 40 Image forming unit 50 Paper transport unit 54 Detection unit 60 Fixing unit 80 Control unit

Claims (9)

An image forming apparatus including a fixing portion for passing a continuous paper on which an unfixed toner image is formed through a fixing nip and fixing the unfixed toner image to the continuous paper.
A transport unit that transports the continuous paper and
A control unit that determines whether or not the posture of the continuous paper conveyed by the transport unit is stable, and if it is determined that the posture of the continuous paper is stable, starts warming up the fixing unit.
An image forming apparatus comprising. A tension applying mechanism for applying tension to the continuous paper is provided.
The image forming apparatus according to claim 1, wherein the control unit starts warming up of the fixing unit when a tension of a predetermined magnitude is applied to the continuous paper by the tension applying mechanism. The image forming apparatus according to claim 2, wherein the control unit stops warming up the fixing unit when the tension applied by the tension applying mechanism becomes smaller than the predetermined magnitude. .. The control unit controls the transfer of the continuous paper by the transfer unit, determines the transfer speed of the continuous paper when determining whether or not the posture of the continuous paper is stable, and sets the unfixed toner image as the continuous. The image forming apparatus according to any one of claims 1 to 3, wherein the speed is slower than the transport speed of the continuous paper when it is fixed on paper. A reception unit for receiving an instruction operation for instructing the start of warming up of the fixing unit is provided.
When the instruction operation is received by the receiving unit, the control unit starts transporting the continuous paper by the transporting unit, and determines whether or not the posture of the continuous paper transported by the transporting unit is stable. The image forming apparatus according to claim 4, further comprising warming up the fixing portion when the determination is made and it is determined that the posture of the continuous paper is stable. A detection unit for detecting meandering of the continuous paper transported by the transport unit is provided.
The control unit determines whether or not the meandering of the continuous paper has converged based on the detection result of the meandering of the continuous paper by the detection unit, and when it is determined that the meandering of the continuous paper has converged, the continuous paper The image forming apparatus according to any one of claims 1 to 5, wherein it is determined that the posture of the paper is stable. A measuring unit for measuring the transport distance of the continuous paper transported by the transport unit is provided.
The control unit determines whether or not the transport distance of the continuous paper has reached a predetermined distance based on the measurement result of the transport distance of the continuous paper by the measurement unit, and the transport distance of the continuous paper is predetermined. The image forming apparatus according to any one of claims 1 to 5, wherein when it is determined that the distance has been reached, it is determined that the posture of the continuous paper is stable. A detection unit that detects meandering of the continuous paper conveyed by the transfer unit, and
A measuring unit that measures the transport distance of the continuous paper transported by the transport unit,
With
The first mode in which the determination of whether or not the posture of the continuous paper is stable is performed based on the detection result of the meandering of the continuous paper by the detection unit, and the measurement result of the transport distance of the continuous paper by the measurement unit. A second mode, which is performed based on the above, is provided in advance.
When the first mode is set, the control unit determines whether or not the meandering of the continuous paper has converged based on the detection result of the meandering of the continuous paper by the detection unit, and determines whether or not the meandering of the continuous paper has converged. When it is determined that the meandering has converged, it is determined that the posture of the continuous paper is stable, while when the second mode is set, it is based on the measurement result of the transport distance of the continuous paper by the measuring unit. , It is determined whether or not the transport distance of the continuous paper has reached a predetermined distance, and when it is determined that the transport distance of the continuous paper has reached a predetermined distance, it is determined that the posture of the continuous paper is stable. The image forming apparatus according to any one of claims 1 to 5, wherein the image forming apparatus is characterized. 7. The predetermined distance is at least the distance from the predetermined working position where the work of joining the continuous papers is performed to the continuous paper passing through the fixing portion, according to claim 7 or 8. The image forming apparatus according to 8.

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