KR20190123063A - Misfeed prevention through controlling retard roller operation of image forming apparatus - Google Patents

Abstract

An image forming apparatus is disclosed. According to the present invention, the image forming apparatus comprises: a printing engine for forming an image on printing paper; a transfer device for transferring the printing paper to the printing engine by using a feed roller and a conveying roller installed to face the feed roller; and a processor which controls the transfer device to transfer the printing paper in an opposite direction of a transfer direction during a preset condition after the printing paper is picked up. The processor controls the transfer device so that both the conveying roller and the feeding roller rotate in a reverse direction of the transfer direction for a predetermined time for separation of the printing paper.

Description

Misfeed prevention through control of conveying roller of image forming apparatus {MISFEED PREVENTION THROUGH CONTROLLING RETARD ROLLER OPERATION OF IMAGE FORMING APPARATUS}

The image forming apparatus is a device that generates, prints, receives, or transmits image data, and examples thereof include a printer, a copy machine, a fax machine, and a multifunction machine integrating these functions.

In the conventional image forming apparatus, when two or more sheets of printing paper are double fed on a transfer path, the image is printed as it is without any special measures.

Therefore, a printing defect occurs in which one page of an image is printed on two or more sheets of printing paper, and a user must find and remove a page in which the printing defect has occurred and reprint the corresponding page. There was discomfort due to waste and reprint.

1 is a block diagram illustrating a simple configuration of an image forming apparatus according to an embodiment of the present disclosure.
FIG. 2 is a diagram schematically illustrating the image forming apparatus of FIG. 1.
3 is a view schematically showing an example of a transport apparatus according to an embodiment of the present disclosure.
4 is a view for explaining the conveyance of paper having a different starting point of conveyance when the conveying apparatus according to an embodiment of the present disclosure performs a reverse rotation operation for a preset time.
5A is a view for explaining the operation of the transfer device according to P1 disclosed in FIG.
5B is a view for explaining the operation of the transfer device according to P2 disclosed in FIG.
5C is a view for explaining the operation of the transfer device according to P4 disclosed in FIG.
6 is a perspective view of a transport apparatus according to an embodiment of the present disclosure.
7A is a view for explaining an operation of transferring a sheet in a conveying direction by a conveying apparatus according to an embodiment of the present disclosure.
FIG. 7B is a view for explaining an operation of back conveying a sheet in a direction opposite to a conveying direction by a conveying apparatus according to an embodiment of the present disclosure.
FIG. 8A is a diagram for describing an operation of the transfer device for P1, P2, and P3 disclosed in FIG. 4.
8B is a view for explaining the operation of the transfer device for P4 disclosed in FIG.
9A is a view for explaining an operation of transferring a sheet in a conveying direction by a conveying apparatus according to another exemplary embodiment of the present disclosure.
FIG. 9B is a view for explaining an operation of back conveying a sheet in a direction opposite to a conveying direction by a conveying apparatus according to another exemplary embodiment of the present disclosure.
FIG. 10A is a diagram for describing an operation of a transfer device for P1, P2, and P3 disclosed in FIG. 4.
FIG. 10B is a view for explaining the operation of the transfer device for P4 disclosed in FIG. 4.
FIG. 11 is a view for explaining the conveyance of paper having different transfer start time points when the conveying apparatus according to one embodiment of the present disclosure performs an operation of rotating the reverse direction only for the paper passing through the sensor for a predetermined time.
12 is a flowchart of a paper conveying method in the image forming apparatus of the present disclosure.

Hereinafter, various embodiments will be described in detail with reference to the accompanying drawings. The embodiments described below may be modified and implemented in various different forms. In order to more clearly describe the features of the embodiments, detailed descriptions of matters well known to those skilled in the art to which the following embodiments belong will be omitted.

Meanwhile, in the present specification, when a configuration is "connected" with another configuration, this includes not only a case in which it is directly connected, but a case in which another configuration is interposed therebetween. In addition, when one configuration "includes" another configuration, this means that, unless specifically stated otherwise, it may further include other configurations without excluding other configurations.

As used herein, the term "image forming job" may refer to various jobs related to an image (eg printing, scanning, or faxing), such as forming an image or generating / storing / transmitting an image file. (job) ”not only means an image forming job, but also may include a series of processes necessary for performing the image forming job.

In addition, an "image forming apparatus" refers to an apparatus for printing print data generated in a terminal apparatus such as a computer onto a recording sheet. Examples of such an image forming apparatus include a copier, a printer, a facsimile, or a multi-function printer (MFP) that implements their functions in a single device. It may mean any device capable of performing an image forming operation, such as a printer, a scanner, a fax machine, a multi-function printer (MFP), or a display device.

In addition, “hard copy” refers to an operation of outputting an image to a print medium such as paper, and the like. “Soft copy” refers to an operation of outputting an image to a display device such as a TV or a monitor. can do.

In addition, the term "content" may mean all kinds of data that is an object of an image forming operation, such as a photo, an image, or a document file.

In addition, "print data" may refer to data converted into a format printable by a printer. On the other hand, if the printer supports direct printing, the file itself may be print data.

In addition, the term “user” may mean a person who performs an operation related to an image forming job by using an image forming apparatus or by using a device connected to the image forming apparatus by wire or wireless. In addition, the “manager” may mean a person who has a right to access all functions and systems of the image forming apparatus. "Administrator" and "User" may be the same person.

1 is a block diagram illustrating a simple configuration of an image forming apparatus according to an embodiment of the present disclosure.

Referring to FIG. 1, the image forming apparatus 100 includes a print engine 110, a conveying apparatus 1, and a processor 140.

The print engine 110 performs an image forming job. In detail, the print engine 110 may perform an image forming operation by forming an image on the image forming medium and transferring the formed image onto the printing paper. A detailed configuration and operation of the print engine 110 will be described later with reference to FIG. 2.

The conveying apparatus 1 moves the loaded printing sheet in the conveying path. Specifically, the transfer device 1 may pick up the print paper loaded in the cassette 10 (see FIG. 2) so that the print paper is provided to the print engine 110, and transfer the picked up print paper to the transfer path. To this end, the conveying apparatus 1 may be provided with at least one driving source and a plurality of rollers. The specific structure and operation | movement of the conveying apparatus 1 are mentioned later with reference to FIG.

The processor 140 controls the components of the image forming apparatus 100. Specifically, when the processor 140 receives the print data from the print control terminal device, the processor 140 controls the operation of the print engine 110 so that the received print data is printed, and the transfer device to provide the print paper to the print engine 110. (1) can be controlled.

The processor 140 may control the transfer device 1 to fundamentally increase separation efficiency between the sheets S in order to prevent feeding.

More specifically, the processor 140 controls the transfer device 1 to transfer the print paper in the transfer direction during the pickup of the print paper S, and then transfers the print paper S for a predetermined time. The conveying apparatus 1 can be controlled to move in the reverse direction of the direction, and again the conveying apparatus 1 can be controlled to move the printing paper S in the conveying direction.

The processor 140 may control the transfer device 1 to rotate both the transfer roller 40 and the paper feed roller 30 in the reverse direction of the transfer direction for a preset time.

The processor 140 may control the conveying apparatus 1 to reversely convey the print sheet passing between the conveying roller 40 and the feed roller 30 at every feed cycle of the print sheet in a direction opposite to the conveying direction.

An image forming apparatus for forming an image on a printing sheet conveyed at a constant speed forms an image with a feeding time of the printing sheet, that is, a feeding period. The feed cycle is determined by the feed speed of the print paper, and the speed of the print paper to be fed in the feed cycle should be constant.

The printing paper S controls the conveying speed of the paper through the arrival time T3 (see FIG. 4) that reaches the position sensed by the sensor 50. By doing so, it is possible to maintain the span without overlapping with the preceding sheet. According to the state in which the paper is detected by the sensor 50, the feed speed may be adjusted by delaying the pickup timing or increasing the paper feed speed.

The feed cycle of the printing paper may vary depending on how the power connection between the drive source and the roller is controlled.

When the front end of the printing paper S passes through the conveying roller 40 and the paper feeding roller 30, the picked printing paper S may be reversely conveyed in the opposite direction to the conveying direction at every feeding period. When the tip of the printing paper S does not pass through the conveying roller 40 and the paper feeding roller 30, the printing paper S picked up can be stopped.

The conveying roller 40 and the feeding roller 30 may be rotated in the opposite direction to the conveying direction periodically according to the conveying cycle.

The conveying apparatus 1 needs to rotate the conveyance roller 40 and the feeding roller 30 in the reverse direction of the conveying direction at predetermined intervals in order to prevent the conveyance of conveying two or more sheets S.

The processor 140 may control the conveying apparatus 1 to convey the printing paper S conveyed in the direction opposite to the conveying direction for a predetermined time in the conveying direction again.

When the print job is executed, the processor 140 may control the degree of reverse rotation of the conveying roller 40 and the paper feeding roller 30 in the conveying direction according to whether the sensor 50 outputs a detection signal.

The processor 140 controls the conveying device 1 to rotate both the conveying roller 40 and the feeding roller 30 in the reverse direction of the conveying direction for a predetermined time when the print sheet S is not detected by the sensor 50. can do.

When the printing paper S is detected by the sensor 50, the processor 140 rotates both the conveying roller 40 and the feeding roller 30 until the printing paper is not detected by the sensor 50 again. Thereafter, the conveying device 1 can be controlled such that both the conveying roller 40 and the feeding roller 30 are rotated in reverse for a predetermined time.

The processor 140 transfers the printing paper S conveyed in the reverse direction of the conveying direction for a preset time until it is detected by the sensor 50, and then conveys the printing paper S in the conveying direction after stopping for a predetermined time. The conveying apparatus 1 can be controlled to convey in the conveying direction.

When the printing sheet S is not detected by the sensor 50, the processor 140 may control the paper feeding roller 30 and the conveying roller 40 to rotate in the transport direction. In addition, when the printing paper S is detected by the sensor 50, the processor 140 may transfer the feeding roller 40 and the feeding roller 30 until the printing paper S is not detected by the sensor 50. ) Can be rotated in the reverse direction of the conveying direction, and then the conveying device 1 can be controlled so that both the conveying roller 40 and the feed roller 30 rotate in the reverse direction of the conveying direction for a predetermined time.

Specific operations related to such transfer control will be described later with reference to FIG. 2.

On the other hand, in the above described and described only a simple configuration constituting the image forming apparatus, various configurations may be additionally provided in the implementation. For example, when the image forming apparatus 100 supports a scan function, a scan unit may be additionally provided, and when the image forming apparatus 100 has a fax transceiving function, the image forming apparatus 100 may further include a fax transceiving unit to display a state of the image forming apparatus. A configuration such as a touch screen may be further provided.

FIG. 2 is a diagram schematically illustrating the image forming apparatus of FIG. 1. Hereinafter, an image forming apparatus 100 having a conveying apparatus according to an embodiment of the present disclosure will be described.

Referring to FIG. 2, the image forming apparatus 100 according to an embodiment of the present disclosure includes a transfer device 1, a print engine 110, and a discharge unit 190.

The conveying apparatus 1 accommodates a predetermined number of print sheets S, and is formed to pick up the print sheets S one by one and supply them to the print engine 110.

The print engine 110 forms a predetermined image on the printing paper S supplied from the conveying apparatus 1. The print engine 110 may include a photosensitive drum 111, a charger 112, an exposure machine 113, a developer 114, a transfer machine 115, and a fixing unit 118. On the other hand, although the print engine 110 and the conveying apparatus 1 are shown as having different configurations, the conveying apparatus 1 may be one configuration in the print engine 110.

The electrostatic latent image is formed on the photosensitive drum 111. Specifically, the photosensitive drum 111 may be formed of an image by the operation of the charger 112 and the exposure unit 113 to be described later. The photosensitive drum 111 may be referred to as an image forming medium, a photosensitive drum, a photosensitive belt, or the like depending on its form.

Hereinafter, in order to facilitate the description, only the configuration of the print engine 110 corresponding to one color will be described by way of example. ), A plurality of chargers 112, a plurality of exposure machines 113, a plurality of developing devices 114, and an intermediate transfer belt.

The charger 112 charges the surface of the photosensitive drum 111 to a uniform electric potential. The charger 112 may be implemented in the form of a corona charger, a charging roller, a charging brush.

The exposure machine 113 forms an electrostatic latent image on the surface of the photosensitive drum 111 by changing the surface potential of the photosensitive drum 111 in accordance with the image information to be printed. As an example, the exposure apparatus 113 may form an electrostatic latent image by irradiating the photosensitive drum 111 with light modulated according to image information to be printed. The exposure apparatus 113 of this type may be referred to as a light scanning machine, and an LED may be used as a light source.

 The developer 114 accommodates the developer therein, and supplies the developer (for example, toner) to the electrostatic latent image to develop the electrostatic latent image into a visible image. The developer 114 may include a developing roller 117 for supplying a developer to an electrostatic latent image. For example, the developer may be supplied from the developing roller 117 to the electrostatic latent image formed on the photosensitive drum 111 by a developing electric field formed between the developing roller 117 and the photosensitive drum 111.

The visible image formed on the photosensitive drum 111 is transferred to printing paper by the transfer machine 115 or an intermediate transfer belt (not shown). The transfer machine 115 can transfer a visible image to a printing sheet by, for example, an electrostatic transfer method. The visible image is attached to the print paper by electrostatic attraction.

The fuser 118 applies heat and / or pressure to the visible image on the print paper to fix the visible image to the print paper. The print job is completed by such a series of processes.

On the other hand, the conveying apparatus 1 may perform an operation of rotating the respective components of the print engine 110 described above. Meanwhile, at the time of implementation, one conveying apparatus 1 may simultaneously rotate a plurality of configurations of the above-described print engine 110, and a plurality of motors may be combined to rotate the plurality of configurations described above.

In addition, the conveying apparatus 1 by this indication is applicable also to an inkjet printer. Therefore, although not shown, the print engine 110 may be configured as an ink jet head for jetting predetermined ink according to the print data.

The discharge unit 190 discharges the print paper on which the predetermined image is formed while passing through the print engine 110 to the outside of the image forming apparatus 100. The discharge unit 190 may be composed of a pair of discharge rollers.

The conveying apparatus 1 according to an embodiment of the present disclosure is to increase the separation efficiency between sheets and has a large capacity provided separately from an automatic document scanning apparatus and an image forming apparatus in which unfeeding, jamming, or heavy feeding of printing paper is a problem. It can also be applied to a transfer device.

According to the transfer apparatus according to the embodiment of the present disclosure as described above, in the image forming apparatus having the transfer apparatus, it is possible to prevent the feeding in advance by increasing the separation efficiency between the sheets, so that the transfer device drive source or the motor is damaged by overload Can be prevented, and damage to parts can be prevented by preventing a feeding phenomenon occurring in the image forming apparatus in advance.

As such, the present disclosure can be applied to the C path-type image forming apparatus as well as the S path-type image forming apparatus. Meanwhile, in the illustrated example, only one loading bin is illustrated and described, but the image forming apparatus may include a plurality of loading bins, and the transfer apparatus 1 may print the printing paper of each loading bin on the print engine 110. Can provide.

Hereinafter, a detailed structure of a conveying apparatus according to an embodiment of the present disclosure configured to separate sheets in order to prevent feeding will be described.

3 is a view schematically showing an example of a transport apparatus according to an embodiment of the present disclosure.

Referring to FIG. 3, the conveying apparatus 1 according to an embodiment of the present disclosure conveys a cassette 10, a pickup roller 20, a paper feed roller 30, a transport roller 40, and a paper feed roller 30. It may include a pressure sensor 50 for detecting the pressure between the roller 40.

The cassette 10 loads printing paper S, and the cassette 10 is formed to accommodate a certain number of printing paper S. FIG.

The pickup roller 20 is installed above the cassette 10, and picks up the loaded paper S and transfers it to the paper feed roller 30. The pickup roller 20 is formed to move the paper S1 located on the top of the paper S loaded on the cassette 10 toward the paper feed roller 30.

The pickup roller 20 is rotated at a pickup position for picking up the paper S loaded on the cassette 10 and at a separation position to separate the pickup roller 20 from the paper S. FIG. The pick-up roller 20 may be located at a pick-up position when performing the conveying operation, and may be located at a spaced position when not performing the conveying operation.

The paper feed roller 30 is installed at the tip of the cassette 10 and moves the paper S loaded on the cassette 10 toward the transfer roller 60. Specifically, the paper feed roller 30 is formed to move the paper S picked up by the pickup roller 20 from the cassette 10 toward the transfer roller 60.

The transfer roller 60 is formed of a pair of rollers which face each other and rotate, and moves the paper S fed by the paper feed roller 30 to the print engine 110.

The conveying roller 40 is provided to face the feed roller 30 and to prevent the feeding of the printing paper S supplied from the cassette 10.

The conveyance roller 40 is rotatable in the forward or reverse direction with respect to the rotation shaft 42. The conveying roller 40 is rotatably coupled to the hinge portion 44 and is movable to a pressing position for pressing the feeding roller 30 and a pressing release position spaced apart from the feeding roller. The conveying roller 40 may rotate to press or release the paper feeding roller 30 in accordance with the movement of the link 46 fixed at one end of the hinge portion 44.

The conveying roller 40 separates the paper when two or more sheets are conveyed in the state in which the feeding roller 30 is pressed, so that only one sheet of paper is conveyed to the print engine 110.

The conveying roller 40 applies a predetermined pressure to the printing paper S passing between the feed roller 30 and the conveying roller 40, and may be formed in a roller shape. The conveying roller 40 is elastically deformed to form a conveying nip through which the printing paper S passes between the sheet feeding roller 30.

Conventionally, the feed roller 30 and the conveyance roller 40 are mutually opposite in rotation direction. Therefore, when two sheets of printing paper are picked up by the pickup roller 20, one sheet of paper is normally conveyed by the sheet feeding roller 30, while the other sheet of paper is picked up by the conveying roller 40. Is returned.

This conventional conveying apparatus can return the bottommost sheet of the several sheets entering the conveying nip of the feed roller 30 and the conveying roller 40 to the upstream immediately before the conveying nip. However, it is not possible to reverse feed the next sheet which enters the feed nip in turn by the bottommost sheet conveyed upstream immediately before the feed nip, and the plurality of sheets are bundled and wedged upstream of the conveying roller 40. May remain in shape. In this way, the sheets conveyed in the bundled state may be conveyed, and the paper may be conveyed in the bundled state, resulting in poor printing.

In order to solve this problem, the conveying apparatus 1 according to the exemplary embodiment of the present disclosure is to improve the printing paper separating ability without losing productivity, and the printing paper 1 is picked up during the preset condition after the printing paper S is picked up. Feed in the direction opposite to the feed direction. It is possible to provide an image forming apparatus in which paper separation capability is improved by essentially separating paper while conveying the picked up paper.

The image forming apparatus 100 according to the exemplary embodiment of the present disclosure may move the printing paper S entering the feeding roller 30 and the conveying roller 40 in a direction opposite to the feeding direction for each printing sheet to be transferred. And a conveying device 1 having a structure and a sequence of operations. The effective paper separation of the conveying device 1 reduces the feeding or defective printing.

The conveying apparatus 1 according to the present disclosure may include a sensor 50.

The sensor 50 may be positioned upstream of the paper feed roller 30, that is, at the front end of the paper feed roller, and detect whether the paper is located at a predetermined position in the conveying direction.

The sensor 50 may determine whether the paper normally proceeds to the transfer roller 60 by detecting the paper that has passed through the paper feeding roller 30 and the conveying roller 40. When the sensor 50 recognizes the paper, the sensor 50 is kept in an on state. When the sensor 50 is changed from the off state to the on state, the processor 140 determines that the front end of the paper S has passed through the sensor 50.

When the sensor 50 is in an off state, the processor 140 may determine that the front end of the paper S is located downstream of the sensor 50.

In addition, a paper detection sensor may be additionally disposed on the paper moving path to check whether the paper is normally transferred in the paper conveying process. The processor 140 may determine whether the printing paper is normally transported according to signals output from the plurality of paper detection sensors.

Here, the engine unit 110 may further include a cash register for providing a printing paper at an accurate time.

The conveying apparatus 1 of the image forming apparatus 100 is a method of conveying printing paper S. In the method of conveying printing paper S, the paper is conveyed in the opposite direction to the conveying direction for each paper conveyed regardless of the leading position of the picked up printing paper S The conveying device can be controlled to reverse feed.

On the other hand, according to the front end position of the picked-up printing paper S, the conveying apparatus may be controlled to transfer the paper back only when the front end of the paper S passes through the sensor 50. This will be described later with reference to FIG. 11.

The processor 140 may control the conveying apparatus 1 to back convey in the direction opposite to the conveying direction at each predetermined period of the printing paper S passing between the conveying roller 40 and the sheet feeding roller 30. The predetermined period may be set to a feeding period according to the feeding speed of the printing paper.

The conveying device 1 is reversed in the conveying direction with respect to all the printing paper S passing between the conveying roller 40 and the feed roller 30 to increase separation performance regardless of the leading position of the picked-up paper S. You can reverse feed in the direction. The processor 140 may control the conveying device 1 to back convey the sheet of printing paper passing between the conveying roller 40 and the sheet feeding roller 30. That is, the picked-up printing paper S is conveyed in the opposite direction to the conveying direction for every sheet of paper passing through the conveying roller 40 and the paper feeding roller 30. The conveying operation of the paper S by the conveying apparatus 1 will be described in detail in FIGS. 4 and 5A to 5C.

The processor 140 may control the conveying apparatus 1 to convey the printing paper S conveyed in the direction opposite to the conveying direction for a predetermined time in the conveying direction again.

On the other hand, as described above, since the printing paper is picked up by the roller from the cassette and provided to the print engine 110, when the coated paper having a high coefficient of friction is coated paper, tracing paper, paper with many perforations, etc. As the coefficient goes up, the feeding can easily occur. If a heavy feed occurs, a margin margin failure or jam may occur.

In the conveying apparatus 1, two or more sheets of printing paper S are simultaneously conveyed due to static electricity generated between the paper S, which is a print medium, or a frictional force change between the printing paper S and the pickup roller 20, and the like. So-called double-feeds can occur. The heavy feeding may cause jams in which the paper is jammed inside the image forming apparatus 100, thereby lowering the transfer reliability.

Paper feed for transporting the print paper (S) to the print engine 110 on the upper side of the transport path to which the print paper (S) is transported in order to prevent the feeding phenomenon occurs in the transfer device 1 according to an embodiment of the present disclosure The roller 30 is disposed, the feed roller 30 is effectively applied by the rotational force in the opposite direction of the conveying path for a predetermined time together with the conveying roller 40 is applied to the lower side of the conveying path in the opposite direction of the conveying path. Since the paper is separated, it is possible to prevent the two or more printing papers S from being simultaneously transferred into the image forming apparatus 100.

4 is a view for explaining the transfer of paper having different transfer start time points when the conveying apparatus according to an embodiment of the present disclosure performs the reverse rotation operation for a predetermined time, and FIGS. 5A to 5C are FIGS. It is a figure for demonstrating operation | movement of the conveying apparatus which concerns on P1 thru | or P4 disclosed in the.

Referring to FIG. 4, P1 represents a conveying process of the paper S when the leading end of the picked up paper S is located immediately downstream of the pickup roller 20 and the transfer nip (P1), and P2 represents the paper S ) Indicates the transfer process of the paper S in the case where the tip of the paper is located between the paper feed roller 30 and the conveyance roller 40 (P2), and P3 is when the leading edge of the paper is located immediately downstream of the sensor 50 ( The conveyance process of the paper S of P3) is shown. P4 represents the conveyance process of the paper S in the case where the front end of the picked-up paper S has passed through the sensor 50 (P4).

First, referring to P1 and FIG. 5A of FIG. 4, the transfer process of the paper S in the case where the front end of the picked-up paper S is located immediately downstream of the pickup roller 20 and the transfer nip P1 will be described. .

The paper S in this case is not detected by the sensor 50.

The paper feed roller 30 and the conveying roller 40 may be rotated in the opposite direction of the conveying direction to convey the paper S in the opposite direction of the conveying direction for a predetermined time T1. At this time, however, since the paper S is not located between the paper feed roller 30 and the conveying roller 40, the paper S is in place in a stopped state. That is, although the paper feed roller 30 and the conveyance roller 40 are rotated in the opposite direction to the conveyance direction, the paper S is kept in a stopped state.

The paper S is stopped for a predetermined time T2 and then conveyed again in the conveying direction until detected by the sensor 50.

When the conveyed sheet S is detected by the sensor 50, the sheet S is conveyed toward the print engine 110 again in the conveying direction when the sheet S comes to be conveyed after stopping for a predetermined time T31.

In order to maintain the paper S, the paper S may be transferred from the pick-up process for a predetermined time T3 to reach the sensor 50. In order to match the preset time T3, the paper S may be transported again after stopping for a predetermined time T31 after reaching the sensor 50.

Next, referring to P2 and P3 of FIG. 4 and FIG. 5B, the paper of the case where the tip of the picked-up paper S is located between the upstream immediately before the transfer nip and the downstream just before the sensor 50 (P2, P3) Examine the transfer process of S).

Since the front end of the paper S is located immediately upstream of the conveying nip, the paper S can be conveyed in a direction opposite to the conveying direction in accordance with the reverse rotation of the feed roller 30 and the conveying roller 40. In addition, since the tip of the sheet S is located immediately downstream of the sensor 50, the sheet S is not detected by the sensor 50.

The conveying apparatus 1 conveys the paper S in a direction opposite to the conveying direction for a predetermined time T1. Thereafter, the conveying apparatus 1 conveys the paper S, which has been conveyed backward after a predetermined time T2, in the conveying direction until it is detected by the sensor 50. When the conveyed paper S is detected by the sensor 50, the conveying apparatus 1 stops the paper S for a predetermined time (T32, T33), and then, when the paper is fed (T3), the print engine ( It is conveyed back to the conveying direction toward 110.

Of the printing paper S passing between the paper feed roller 30 and the conveying roller 40, the paper S which is not detected by the sensor 50 is conveyed backward by the preset time T1, during this time. (T1) The printing paper S can pass between the paper feed roller 30 and the conveyance roller 40. The preset time T1 may be precomputed in the image forming apparatus 100 by using the transfer speed and the movement distance of the printing paper.

The conveying roller 40 may rotate in a direction opposite to the conveying direction for a predetermined time for the reverse conveyance of the paper S. FIG. Similarly, the paper feed roller 30 can also rotate together with the transfer roller 40 in a direction opposite to the conveying direction for a predetermined time. The paper feed roller 30 and the conveyance roller 40 can be rotated together in the opposite direction to the conveying direction so that the plurality of sheets of paper can be reversely conveyed to be surely returned.

When the paper S is conveyed backward, the conveying roller 40 becomes the driving side, and the feeding roller 30 becomes the driven side, so that the sheet disposed at the lowest level of the paper stack directly contacting the conveying roller 40 ( The greatest returned force acts on S2). Accordingly, even when the paper S is conveyed backward, separation between sheets of the paper stack occurs. That is, even when the paper S is sent back in the opposite direction to the conveying direction, the paper can be separated and the feeding can be effectively prevented.

In addition, by conveying the sheet back so that the sheet bundle exits the conveying nip, the conveying roller 40 can be rotated in the conveying direction without the sheet bundle contacting the conveying roller 40. As a result, in the conventional conveying apparatus, the problem that the remaining paper stack is in contact with the surface of the conveying roller 40 in addition to the uppermost sheet conveyed after separation by the conveying roller may stop the rotation of the conveying roller 40.

The back conveyed paper S is again conveyed in the conveying direction, and when conveyed in the conveying direction, the feed roller 30 is driven and the conveying roller 40 is driven. The largest conveyance force acts on the paper S1 disposed on the uppermost directly contacting. Accordingly, the separation between the sheets of the paper stack occurs once more when the paper S is transferred.

After the predetermined time T2 has elapsed, the paper S stopped for a predetermined time T1 is conveyed again in the conveying direction until it is detected by the sensor 50. When the conveyed sheet S is detected by the sensor 50, the sheet S is conveyed in the conveying direction again toward the print engine 110 when it is time to convey the sheet after stopping for a predetermined time T32 and T33. .

FIG. 5: B is a figure which shows the conveyance of the paper S in the case where the front-end | tip of the paper S is located between the paper feed roller 30 and the conveyance roller 40 (P2). However, if the leading edge of the paper is positioned between the paper feed roller 30 and the conveying roller 40 until immediately before the sensor 50, the conveying operation of the paper and the driving of the conveying device 1 for conveying the paper S are equal. Therefore, the description of the case where the leading edge of the paper is located immediately downstream of the sensor 50 (P3) will be omitted.

Finally, referring to FIGS. 4 and 5C, the transfer process of the paper S in the case where the front end of the picked-up paper S passes through the sensor 50 (P4) will be described.

The paper S is detected by the sensor 50 because the tip of the paper S can be located immediately upstream of the sensor 50.

The conveying apparatus 1 reversely conveys the sheet S in a direction opposite to the conveying direction until the sensor 50 does not detect the sheet S. FIG. If the paper S is not detected by the sensor 50 due to the reverse feeding, the conveying apparatus 1 may feed the paper S for a predetermined time T1, such as a process of conveying the paper S of P2 and P3. Feed in the direction opposite to the feed direction.

The conveying apparatus 1 conveys the paper S again in the conveying direction until the paper S, which has been conveyed back after a predetermined time T2, is not detected by the sensor 50. When the conveyed sheet S is detected by the sensor 50, the sheet S is conveyed toward the print engine 110 again in the conveying direction when the sheet S is time to be conveyed after stopping for a predetermined time T34.

The paper S in which a part of the paper S has passed through the sensor 50 is conveyed back until the sensor 50 does not detect the paper S, and when the sensor 50 is turned off, the paper S is S) is conveyed as in P2 of FIG. That is, the paper S which has been conveyed back until the paper S is not sensed by the sensor 50 is further conveyed by the paper S by a preset time T1.

The conveying roller 40 rotates in the direction opposite to the conveying direction for a predetermined time T1 and a time until the sheet S is not detected by the sensor 50 for the reverse conveyance of the sheet S. FIG. Similarly, the paper feed roller 30 also rotates with the conveyance roller 40 in the direction opposite to the conveyance direction. Even when the paper S is sent back in the opposite direction to the conveying direction, the paper can be separated and the feeding can be effectively prevented.

The back conveyed sheet S is again conveyed in the conveying direction, and separation between sheets of the sheet of paper occurs even when the sheet S is conveyed in the conveying direction again.

 The conveying roller 40 and the paper feeding roller 30 may have a time of reverse rotation according to the feed start position of the paper S through the detection signal output of the sensor 50.

Specifically, if the picked-up paper S is not detected by the sensor 50, the paper feed roller 30 and the conveying roller 40 convey the paper S in a direction opposite to the conveying direction for a preset time T1. To rotate in the opposite direction of the feed direction. When the picked-up paper S is detected by the sensor 50, the feeding roller 30 and the conveying roller 40 move in the opposite directions of the conveying direction until the paper S is not detected by the sensor 50. It can rotate in the direction opposite to the conveying direction for conveying. Thereafter, the paper feed roller 30 and the conveying roller 40 are moved in opposite directions to each other in order to feed the paper S in a direction opposite to that of the paper, such as when the paper S is not detected by the sensor 50. Can rotate.

The conveying apparatus 1 according to an exemplary embodiment of the present disclosure may be used together with various heavy conveying detection apparatuses, such as an ultrasonic type heavy feed detecting device capable of detecting a heavy feed, a thickness varying heavy feed detecting device, and a conveying roller motion varying heavy feed detecting device. Can be.

When using the conveyance detection device together with the conveying device according to an embodiment of the present disclosure it is possible to detect the middle feed that can occur even if the reverse feed operation for each sheet of paper conveyed, and stops the paper feed quickly when the heavy feed is detected And since the stack of conveyed paper can be returned to the cassette 10, the life of the parts constituting the conveying device 1 can be increased.

6 is a perspective view of a transport apparatus according to an embodiment of the present disclosure.

Referring to FIG. 6, the conveying apparatus 1 according to the exemplary embodiment of the present disclosure may include a pickup roller 20, a paper feed roller 30, a transport roller 40, a paper feed motor 120, a paper feed clutch 150, The pickup clutch 160 and the sensor 50 may be included.

6 is a view showing a specific structure of the conveying apparatus 1, and description of the pickup roller 20, the paper feeding roller 30, the conveying roller 40, and the sensor 50 described above will be omitted.

The feed motor 120 generates a rotational force capable of rotating the feed roller 30, the pickup roller 20, and the conveyance roller 40. The rotational force of the feed motor 120 is transmitted to the feed roller 30 through the feed clutch 150. For example, when the feed clutch 150 is turned on, the rotational force of the feed motor 120 is transmitted to the feed roller 30 and the pickup roller 20 to feed the feed roller 30 and the pickup roller 20. Rotates. On the contrary, when the paper feed clutch 150 is turned off, the rotational force of the paper feed motor 120 is not transmitted to the paper feed roller 20 so that the paper feed roller 20 and the pickup roller 13 do not rotate. That is, the pickup roller 20 is configured to rotate together when the paper feed roller 30 rotates.

The rotational force of the feed motor 120 is transmitted to the pickup roller cam 161 through the pickup clutch 160 to lower the pickup roller 20. For example, when the pickup clutch 160 is turned on, the rotational force of the feed motor 120 is transmitted to the pickup roller cam 161 so that the pickup roller cam 161 rotates. The pickup roller 20 is lowered by the rotation of the pickup roller cam 161 to contact the sheet S of the cassette 10.

On the contrary, when the pickup clutch 160 is turned off, the rotational force of the feed motor 120 is not transmitted to the pickup roller cam 161 so that the pickup roller cam 161 does not press the pickup roller 20 downward. Therefore, the pickup roller 20 maintains the state spaced apart from the paper S of the cassette 10 by the pickup roller spring 21.

The paper feed clutch 150 and the pickup clutch 160 may be implemented as an electronic clutch that may be controlled on / off by the processor 140.

The rotational force of the paper feed motor 120 is transmitted to the conveying roller 40 to rotate the conveying roller 40. The conveyance roller 40 is directly connected to the feed motor 120. When the feed motor 120 operates, the conveyance roller 40 also rotates in one direction.

When the paper S picked up from the cassette 10 is conveyed, the conveying roller 40 rotates in the conveying direction of the paper by the rotation of the paper feed roller 30 so that the paper S is conveyed toward the print engine 110. Be sure to The picked-up paper S is back-fed in the direction opposite to the conveying direction for a predetermined time for separation between the sheets S. In order to reverse feed the paper S, both the conveying roller 40 and the paper feeding roller 30 are rotated in the opposite directions of the conveying direction of the paper so that the paper S is conveyed toward the cassette 10.

The paper S back conveyed for a preset time is conveyed in the conveying direction again. Even when it is conveyed in the conveying direction again, separation between the paper sheets S occurs by the paper feeding roller 30 and the conveying roller 40.

When the paper is picked up, the paper feed roller 30 and the conveyance roller 40 may rotate in the opposite direction to the conveying direction for a predetermined time T1. The predetermined time T1 may be set to a time at which the leading end of the paper S may exit between the paper feed roller 30 and the conveyance roller 40. The preset time T1 is set to allow the leading edge of the paper S to exit between the paper feed roller 30 and the transfer roller 40 in consideration of the type of paper S, the strength of the motor, and the degree of rotation of the roller. Can be.

7A is a view for explaining an operation of transferring a sheet in a conveying direction by a conveying apparatus according to an embodiment of the present disclosure.

Referring to FIG. 7A, the feeding motor 120 is turned on and the feeding clutch 150 is turned on so that the conveying apparatus 1 according to an embodiment of the present disclosure conveys the printing paper S in the conveying direction. Then, the feed motor 120 rotates, the rotational force of the feed motor 120 is transmitted to the feed roller 30 by the feed clutch 150, and the feed roller 30 rotates.

At this time, since the pickup roller 20 is connected to the paper feed roller 30, when the paper feed roller 30 rotates, the pickup roller 20 also rotates. In this case, the pickup clutch 160 is turned on. Since the pickup clutch 160 is turned on, the rotational force of the paper feed motor 120 is transmitted to the pickup roller cam 161 so that the pickup roller cam 161 rotates. The pickup roller 20 is lowered by the rotation of the pickup roller cam 161 to contact the sheet S of the cassette 10.

Therefore, the paper S of the cassette 10 is supplied between the paper feed roller 30 and the conveyance roller 40 by the rotation of the pickup roller 20. Moreover, since the conveyance roller lifting cam 151 which raises and lowers the conveyance roller 40 is in the position which does not pressurize the conveyance roller 40, the conveyance roller 40 is urged upwards by the elastic member 41, and the sheet feeding roller ( 30) at constant pressure.

At this time, the rotational force of the paper feed motor 120 is also transmitted to the torque limiter provided coaxially with the conveyance roller 40. At this time, the torque in the direction opposite to the rotation direction of the paper feed roller 20 is transmitted to the torque limiter. However, since the paper feeding roller 30 and the conveying roller 40 which are made of rubber with high friction coefficient are in contact with each other, and the torque limiter is configured to slip at a predetermined load or more, the feeding roller 30 is conveyed when it is rotated. The roller 40 is rotated according to the paper feed roller 30. For example, when the paper feed roller 30 rotates clockwise, the conveyance roller 40 will rotate counterclockwise by the paper feed roller 30. That is, the paper feed roller 30 and the conveyance roller 40 are respectively rotated in the conveying direction of the paper. Thereby, the paper S is conveyed in the conveying direction.

FIG. 7B is a view for explaining an operation of back conveying a sheet in a direction opposite to a conveying direction by a conveying apparatus according to an embodiment of the present disclosure.

Referring to FIG. 7B, the paper feed clutch 150 is turned off for a predetermined time T1 for the conveying apparatus 1 according to an embodiment of the present disclosure to back convey the printing paper in a direction opposite to the conveying direction. The motor 120 is turned on. Then, the feed motor 120 rotates, but the rotational force of the feed motor 120 is blocked by the feed clutch 150 and is not transmitted to the feed roller 30. Therefore, the paper feed roller 30 can rotate freely. At this time, since the pickup roller 20 is connected to the paper feed roller 30, the pickup roller 20 does not rotate unless the paper feed roller 30 is rotated.

In addition, the pickup clutch 160 is turned off. Then, the pickup roller 20 maintains the position raised by the pickup roller spring 21 to be spaced apart from the paper S of the cassette 10. Therefore, even if the feed motor 120 rotates, the paper S of the cassette 10 is not supplied between the feed roller 30 and the conveyance roller 40.

In addition, since the conveyance roller lowering cam 151 which lowers the conveyance roller 40 is in the position which does not pressurize the conveyance roller 30, the conveyance roller 40 is urged upwards by the elastic member 41, and the feed roller ( 30) at constant pressure.

At this time, the rotational force of the paper feed motor 100 is transmitted to the conveyance roller 30. Specifically, when the feed motor 120 rotates, the conveyance roller 40 rotates clockwise, which is the direction opposite to the conveying direction.

Since the feed roller 30 and the conveyance roller 40 are in contact with each other, and the feed roller 30 is freely rotatable, the feed roller 30 rotates the conveyance roller 40 when the conveyance roller 40 rotates. Will rotate accordingly. For example, when the conveyance roller 40 rotates clockwise, the feed roller 30 will rotate by the conveyance roller 40 counterclockwise. That is, the conveyance roller 40 and the feed roller 30 each rotate in the opposite direction to the conveyance direction. Thereby, the paper S is conveyed in the direction opposite to the conveying direction.

8A is a diagram for explaining the operation of the conveying apparatus 1 when the tip of the sheet S is located downstream of the sensor 50 (P1, P2, P3).

Referring to FIG. 8A, when the leading edge of the picked-up paper S is positioned before passing through the sensor 50 (P1, P2, P3), it is fed for a predetermined time T1 for every sheet S to be transferred. The roller 30 and the conveyance roller 40 may be reversely rotated in the direction opposite to the conveying direction.

More specifically, the conveying apparatus 1 conveys the printing paper S in the conveying direction during the process of picking up the printing paper S, and subsequently conveys the paper S for a predetermined time T1. To this end, the feed clutch 150 is turned off and the feed motor 120 is turned on. Then, the feed motor 120 rotates, but the rotational force of the feed motor 120 is blocked by the feed clutch 150 and is not transmitted to the feed roller 30. Therefore, the paper feed roller 30 can rotate freely. At this time, since the pickup roller 20 is connected to the paper feed roller 30, the pickup roller 20 does not rotate unless the paper feed roller 30 is rotated.

In addition, the pickup clutch 160 is turned off. Then, the pickup roller 20 maintains the position raised by the pickup roller spring 21 to be spaced apart from the paper S of the cassette 10. Therefore, even if the feed motor 120 rotates, the paper S of the cassette 10 is not supplied between the feed roller 30 and the conveyance roller 40.

In addition, since the conveyance roller lowering cam 151 which lowers the conveyance roller 40 is in the position which does not pressurize the conveyance roller 30, the conveyance roller 40 is urged upwards by the elastic member 41, and the feed roller ( 30) at constant pressure.

At this time, the rotational force of the paper feed motor 100 is transmitted to the conveyance roller 30. Specifically, when the feed motor 120 rotates, the conveyance roller 40 rotates clockwise, which is the direction opposite to the conveying direction.

Since the feed roller 30 and the conveyance roller 40 are in contact with each other, and the feed roller 30 is freely rotatable, the feed roller 30 rotates the conveyance roller 40 when the conveyance roller 40 rotates. Will rotate accordingly. For example, when the conveyance roller 40 rotates clockwise, the feed roller 30 will rotate by the conveyance roller 40 counterclockwise. That is, the conveyance roller 40 and the feed roller 30 each rotate in the opposite direction to the conveyance direction. Accordingly, the paper S may be stopped or back-fed for a preset time T1.

The sensor 50 remains off for the preset time T1.

The paper S stopped or reversely conveyed by the reverse rotation of the paper feed roller 30 and the conveyance roller 40 for the preset time T1 is stopped for a predetermined time T2, and the paper S again returns to the sensor ( Until it is detected at 50). The driving of the conveying apparatus 1 for conveying the stationary or reverse conveyed paper S in the conveying direction will be described. The feeding motor 120 is on, and the feeding clutch 150 is on. Then, the feed motor 120 rotates, the rotational force of the feed motor 120 is transmitted to the feed roller 30 by the feed clutch 150, and the feed roller 30 rotates.

At this time, since the pickup roller 20 is connected to the paper feed roller 30, when the paper feed roller 30 rotates, the pickup roller 20 also rotates. In this case, the pickup clutch 160 is turned on. Since the pickup clutch 160 is turned on, the rotational force of the paper feed motor 120 is transmitted to the pickup roller cam 161 so that the pickup roller cam 161 rotates. The pickup roller 20 is lowered by the rotation of the pickup roller cam 161 to contact the sheet S of the cassette 10.

Therefore, the paper S of the cassette 10 is supplied between the paper feed roller 30 and the conveyance roller 40 by the rotation of the pickup roller 20. Moreover, since the conveyance roller lifting cam 151 which raises and lowers the conveyance roller 40 is in the position which does not pressurize the conveyance roller 40, the conveyance roller 40 is urged upwards by the elastic member 41, and the sheet feeding roller ( 30) at constant pressure.

At this time, the rotational force of the paper feed motor 120 is also transmitted to the torque limiter provided coaxially with the conveyance roller 40. At this time, the torque in the direction opposite to the rotation direction of the paper feed roller 20 is transmitted to the torque limiter. However, since the paper feeding roller 30 and the conveying roller 40 which are made of rubber with high friction coefficient are in contact with each other, and the torque limiter is configured to slip at a predetermined load or more, the feeding roller 30 is conveyed when it is rotated. The roller 40 is rotated according to the paper feed roller 30. For example, when the paper feed roller 30 rotates clockwise, the conveyance roller 40 will rotate counterclockwise by the paper feed roller 30. That is, the paper feed roller 30 and the conveyance roller 40 are respectively rotated in the conveying direction of the paper. Thereby, printing paper S moves to a conveyance direction.

After the printing paper S is sensed by the sensor 50, the paper S is conveyed toward the print engine 110 after the preset time T3 has passed in order to maintain the paper interval. After the paper S is sensed by the sensor 50, the paper S is stopped for a time period T31, T32, T33 until the time T3.

In this case, the sensor 50 remains off during the time periods T31, T32, and T33 until the time T3 is reached.

In order to stop the paper S, the feeding clutch 150 is turned off and the feeding motor 120 is turned on. Then, the feed motor 120 rotates, but the rotational force of the feed motor 120 is blocked by the feed clutch 150 and is not transmitted to the feed roller 30.

In addition, the pickup clutch 160 is turned off. Then, the pickup roller 20 maintains the position raised by the pickup roller spring 21 to be spaced apart from the paper S of the cassette 10. Therefore, even if the feed motor 120 rotates, the paper S of the cassette 10 is not supplied between the feed roller 30 and the conveyance roller 40.

When the paper S reaches the sensor 50 and reaches the time T3 from the start of the conveyance, the conveying apparatus 1 again moves the print sheet S in the conveying direction.

FIG. 8B is a view for explaining the operation of the conveying apparatus 1 when the conveyance is started at a position that has completely passed through the positioner sensor 50 at the tip of the sheet S. FIG.

Referring to FIG. 8B, when the leading edge of the picked-up paper S is positioned in the state of passing through the sensor 50, the transfer device 1 may be positioned until the leading edge of the paper S is positioned downstream of the sensor 50. The paper S can be conveyed backward. The processor 140 may control the paper feed roller 30 and the transfer roller 40 to reversely rotate in a direction opposite to the transfer direction until the sensor 50 is turned off.

The operation of the conveying apparatus 1 for back conveying the sheet S until the sheet S is not detected by the sensor 50 will be described.

The paper feed clutch 150 is turned off and the paper feed motor 120 is turned on until the sensor 50 does not detect the paper S due to the reverse feeding of the paper S. FIG. Then, the feed motor 120 rotates, but the rotational force of the feed motor 120 is blocked by the feed clutch 150 and is not transmitted to the feed roller 30. Therefore, the paper feed roller 30 can rotate freely. At this time, since the pickup roller 20 is connected to the paper feed roller 30, the pickup roller 20 does not rotate unless the paper feed roller 30 is rotated.

In addition, the pickup clutch 160 is turned off. Then, the pickup roller 20 maintains the position raised by the pickup roller spring 21 to be spaced apart from the paper S of the cassette 10. Therefore, even if the feed motor 120 rotates, the paper S of the cassette 10 is not supplied between the feed roller 30 and the conveyance roller 40.

In addition, since the conveyance roller lowering cam 151 which lowers the conveyance roller 40 is in the position which does not pressurize the conveyance roller 30, the conveyance roller 40 is urged upwards by the elastic member 41, and the feed roller ( 30) at constant pressure.

At this time, the rotational force of the paper feed motor 100 is transmitted to the conveyance roller 30. Specifically, when the feed motor 120 rotates, the conveyance roller 40 rotates clockwise, which is the direction opposite to the conveying direction.

Since the feed roller 30 and the conveyance roller 40 are in contact with each other, and the feed roller 30 is freely rotatable, the feed roller 30 rotates the conveyance roller 40 when the conveyance roller 40 rotates. Will rotate accordingly. For example, when the conveyance roller 40 rotates clockwise, the feed roller 30 will rotate counterclockwise by the conveyance roller 40. That is, the conveyance roller 40 and the feed roller 30 each rotate in the opposite direction to the conveyance direction.

After the sensor 50 is turned off by the reverse conveyance of the paper S, the paper S is formed from the paper S when the tip of the paper S described in FIG. 8A is located downstream of the sensor 50. In the same manner, the back feed is carried out for the preset time T1, and the motor is stopped for a predetermined time T2, and then transferred in the transport direction until the paper S is detected by the sensor 50, and again stopped for a predetermined time T34. When the paper is to be conveyed later, the paper is conveyed toward the engine 110. The operation of the conveying apparatus for conveying the sheet S which has been conveyed back until the sensor 50 is turned off is the same as that of the conveying apparatus 1 described with reference to FIG.

9A is a view for explaining an operation of conveying a sheet of paper in a conveying direction by a conveying apparatus according to another embodiment of the present disclosure, and FIG. 9B is a direction opposite to the conveying direction of a conveying apparatus according to another embodiment of the present disclosure. It is a figure for demonstrating the operation | movement which reversely conveys.

The conveying apparatus 1 according to another embodiment of the present disclosure may include a pickup roller 20, a paper feed roller 30, a transport roller 40, a paper feed motor 120, a transport motor 130, a pickup clutch 160, It may include a sensor 50.

Since the pickup roller 20, the paper feed roller 30, the transfer roller 40, and the sensor 50 are the same as the transfer apparatus 1 described with reference to FIG. 6, description thereof will be omitted.

9A and 9B, the paper feed motor 120 generates a rotational force capable of rotating the paper feed roller 30 and the pickup roller 20. The feed motor 120 may selectively rotate in the forward or reverse direction, and the feed roller 30 and the pickup roller 20 connected to the feed motor 120 may also rotate in the forward or reverse direction. Here, the expressions forward and reverse are used to distinguish the rotation direction for convenience of description.

When the feed motor 120 rotates in the forward direction, the rotational force of the feed motor 120 is transmitted to the feed roller 30 and the pickup roller 20 so that the feed roller 30 and the pickup roller 20 rotate in the forward direction. . That is, the paper feed roller 30 and the pickup roller 20 can be rotated in the clockwise direction, which is the paper feed direction, by the forward rotation of the paper feed motor 120 '. On the contrary, when the feed motor 120 'rotates in the reverse direction, the reverse rotational force of the feed motor 120 is transmitted to the feed roller 30 and the pickup roller 20 so that the feed roller 30 and the pickup roller 20 Rotate in the reverse direction. That is, the paper feed roller 30 and the pickup roller 20 may rotate in the counterclockwise direction opposite to the paper feed direction by the reverse rotation of the paper feed motor 120. The pickup roller 20 may be configured to rotate in the same rotational direction as that of the paper feed roller 30.

The rotational force of the conveying motor 130 is transmitted to the conveying roller 40 to rotate the conveying roller 40. The conveyance roller 40 is directly connected to the conveyance motor 130. When the conveyance motor 130 'operates, the conveyance roller 40 also rotates in one direction.

The rotational force of the conveying motor 130 is transmitted to the pickup roller cam 161 through the pickup clutch 160 to lower the pickup roller 20. For example, when the pickup clutch 160 is turned on, the rotational force of the transfer motor 130 is transmitted to the pickup roller cam 161 so that the pickup roller cam 161 rotates. The pickup roller 20 is lowered by the rotation of the pickup roller cam 161 to contact the sheet S of the cassette 10.

On the contrary, when the pickup clutch 160 ′ is turned off, the rotational force of the conveying motor 130 is not transmitted to the pickup roller cam 161, so that the pickup roller cam 161 does not press the pickup roller 20 downward. Therefore, the pickup roller 20 maintains the state spaced apart from the paper S of the cassette 10 by the pickup roller spring 21.

The pickup clutch 160 may be implemented as an electronic clutch that may be controlled on / off by the processor 140.

When the paper is picked up, the paper feed roller 30 and the conveyance roller 40 may be reversely rotated in a direction opposite to the conveying direction for a predetermined time T1.

With reference to FIG. 9A, the drive of the conveying apparatus 1 which conveys the sheet | seat S which was stopped or back conveyed in the conveyance direction is demonstrated.

Referring to FIG. 9A, the paper feed motor 120 may be rotated in the forward direction. Then, the forward rotational force of the feed motor 120 is transmitted to the feed roller 30 and the pickup roller 20 so that the feed roller 30 and the pickup roller 20 rotate in the forward direction. That is, the paper feed roller 30 and the pickup roller 20 may rotate in the clockwise direction, which is the paper feed direction, by the forward rotation of the paper feed motor 120.

At this time, the transfer motor 130 is turned on and the pickup clutch 160 is turned on. Then, the rotational force of the conveying motor 130 is transmitted to the conveying roller 40, and the conveying roller 40 rotates clockwise which is a direction opposite to a conveying direction. Since the pickup clutch 160 is in an on state, the rotational force of the transfer motor 130 is transmitted to the pickup roller cam 161 so that the pickup roller cam 161 rotates. The pickup roller 20 is lowered by the rotation of the pickup roller cam 161 to contact the sheet S of the cassette 10.

Therefore, the paper S of the cassette 10 is supplied between the paper feed roller 30 and the conveyance roller 40 by the rotation of the pickup roller 20. Moreover, since the conveyance roller lifting cam 151 which raises and lowers the conveyance roller 40 is in the position which does not pressurize the conveyance roller 40, the conveyance roller 40 is urged upwards by the elastic member 41, and the sheet feeding roller ( 30) at constant pressure.

At this time, the rotational force of the conveying motor 130 is transmitted also to the torque limiter provided coaxially with the conveying roller 40. At this time, the torque in the direction opposite to the rotation direction of the paper feed roller 30 is transmitted to the torque limiter. However, since the paper feeding roller 30 and the conveying roller 40 which are made of rubber with high friction coefficient are in contact with each other, and the torque limiter is configured to slip at a predetermined load or more, the feeding roller 30 is conveyed when it is rotated. The roller 40 is rotated according to the paper feed roller 30. Therefore, when the paper feed roller 30 rotates clockwise, the conveyance roller 40 will rotate counterclockwise by the paper feed roller 30. That is, the paper feed roller 30 and the conveyance roller 40 are respectively rotated in the conveying direction of the paper.

By the forward rotation of the paper feed roller 30 and the conveyance roller 40, the paper is separated in the paper while the paper is conveyed in the conveying direction.

Referring to FIG. 9B, an operation of rotating the paper feed roller 30 and the conveying roller 40 to rotate the paper S in a direction opposite to the conveying direction will be described.

The feed motor 120 rotates in the reverse direction. Then, the reverse rotational force of the feed motor 120 is transmitted to the feed roller 30 and the pickup roller 20 so that the feed roller 30 and the pickup roller 20 rotate in the reverse direction. That is, the paper feed roller 30 and the pickup roller 20 rotate in the counterclockwise direction opposite to the paper feed direction.

At this time, the transfer motor 130 is turned on and the pickup clutch 160 is turned off. Then, the rotational force of the conveying motor 130 is transmitted to the conveying roller 40, and the conveying roller 40 rotates clockwise which is a direction opposite to a conveying direction. Since the pickup clutch 160 is in an off state, the pickup roller 20 may be spaced apart from the paper S of the cassette 10 by maintaining the raised position by the pickup roller spring 21. Therefore, even if the feeding motor 120 rotates in reverse, the paper S of the cassette 10 is kept in a stopped state.

As a result, when the front end of the paper S is positioned between the transport roller 40 and the paper feed roller 30, the paper S is conveyed backward, and the front end of the paper S is fed to the transport roller 40. If it does not reach between the rollers 30, the paper S will remain stationary.

Accordingly, due to the reverse rotation of the paper feed roller 30 and the conveyance roller 40, the paper may be reversely conveyed and sufficient separation may occur between the paper sheets.

FIG. 10A is a diagram for explaining the operation of the conveying apparatus 1 when the leading end of the paper S is located downstream of the sensor 50.

Referring to FIG. 10A, when the leading edge of the picked-up paper S is positioned before passing through the sensor 50, the paper feed roller 30 and the conveying roller for a predetermined time T1 for every sheet of paper S to be conveyed. 40 may reversely rotate in the direction opposite to the conveying direction.

In order to reverse feed the paper S for the preset time T1, the feed motor 120 is rotated in the reverse direction, and the reverse rotational force of the feed motor 120 is transmitted to the feed roller 30 and the pickup roller 20. The paper feed roller 30 and the pickup roller 20 rotate in the reverse direction. That is, the paper feed roller 30 and the pickup roller 20 rotate in the counterclockwise direction opposite to the paper feed direction.

At this time, the transfer motor 130 is turned on and the pickup clutch 160 is turned off. Then, the rotational force of the conveying motor 130 is transmitted to the conveying roller 40, and the conveying roller 40 rotates clockwise which is a direction opposite to a conveying direction. Since the pick-up clutch 160 is in an off state, the pick-up roller 20 is maintained at a raised position by the pick-up roller spring 21 to be spaced apart from the paper S of the cassette 10. Therefore, even if the feeding motor 120 rotates in the reverse direction, the sheet S of the cassette 10 is kept in a stopped state.

Due to the reverse rotation of the paper feed roller 30 and the conveyance roller 40, the paper is conveyed back, and sufficient separation may occur between the paper sheets.

Referring to FIG. 10A, the paper S stopped or reversely transported by the reverse rotation of the paper feed roller 30 and the conveyance roller 40 for a preset time T1 stops for a predetermined time T2, and then the paper again. It is conveyed in the conveyance direction until S is detected by the sensor 50.

In this case, the feed motor 120 is rotated in the forward direction, and the forward rotational force of the feed motor 120 is transmitted to the feed roller 30 and the pickup roller 20 so that the feed roller 30 and the pickup roller 20 are in the forward direction. Rotate That is, the paper feed roller 30 and the pickup roller 20 may rotate in the clockwise direction, which is the paper feed direction, by the forward rotation of the paper feed motor 120.

At this time, the transfer motor 130 is turned on and the pickup clutch 160 is turned on. Then, the rotational force of the conveying motor 130 is transmitted to the conveying roller 40, and the conveying roller 40 rotates clockwise which is a direction opposite to a conveying direction. Since the pickup clutch 160 is in an on state, the rotational force of the transfer motor 130 is transmitted to the pickup roller cam 161 so that the pickup roller cam 161 rotates. The pickup roller 20 is lowered by the rotation of the pickup roller cam 161 to contact the sheet S of the cassette 10.

Therefore, the paper S of the cassette 10 is supplied between the paper feed roller 30 and the conveyance roller 40 by the rotation of the pickup roller 20. Moreover, since the conveyance roller lifting cam 151 which raises and lowers the conveyance roller 40 is in the position which does not pressurize the conveyance roller 40, the conveyance roller 40 is urged upwards by the elastic member 41, and the sheet feeding roller ( 30) at constant pressure.

At this time, the rotational force of the conveying motor 130 is transmitted also to the torque limiter provided coaxially with the conveying roller 40. At this time, the torque in the direction opposite to the rotation direction of the paper feed roller 30 is transmitted to the torque limiter. However, since the paper feeding roller 30 and the conveying roller 40 which are made of rubber with high friction coefficient are in contact with each other, and the torque limiter is configured to slip at a predetermined load or more, the feeding roller 30 is conveyed when it is rotated. The roller 40 is rotated according to the paper feed roller 30. Therefore, when the paper feed roller 30 rotates clockwise, the conveyance roller 40 will rotate counterclockwise by the paper feed roller 30. That is, the paper feed roller 30 and the conveyance roller 40 are respectively rotated in the conveying direction of the paper. Thereby, the paper S is conveyed in the conveying direction. As paper is conveyed by the forward rotation of the paper feed roller 30 and the conveyance roller 40, separation between papers occurs once more.

FIG. 10B is a view for explaining the operation of the conveying apparatus 1 when the conveyance is started at a position that has completely passed through the positioner sensor 50 at the tip of the paper S. FIG.

In this case, the paper feed motor 120 is rotated backward until the sensor 50 does not detect the paper S due to the backward movement of the paper S. Then, the reverse rotational force of the feed motor 120 is transmitted to the feed roller 30 and the pickup roller 20 so that the feed roller 30 and the pickup roller 20 rotate in the reverse direction. That is, the paper feed roller 30 and the pickup roller 20 rotate in the counterclockwise direction opposite to the paper feed direction.

At this time, the transfer motor 130 'is turned on, and the pickup clutch 160' is turned off. Then, the rotational force of the conveying motor 130 'is transmitted to the conveying roller 40, and the conveying roller 40 rotates in the clockwise direction opposite to the conveying direction. Since the pickup clutch 160 ′ is in an off state, the pickup roller 20 is maintained at a raised position by the pickup roller spring 21 to be spaced apart from the paper S of the cassette 10.

The paper S, which has been conveyed back until the sensor 50 is turned off, has a preset time T1 similar to the paper S when the front end of the paper S described in FIG. 10A is located downstream of the sensor 50. ) Is reversely transported, stopped for a predetermined time T2, and then transferred in the conveying direction until the paper S is detected by the sensor 50, and then stopped for a predetermined time T34 and then conveyed. The operation of the conveying apparatus for conveying the sheet S which has been conveyed back until the sensor 50 is turned off is the same as that of the conveying apparatus 1 described with reference to FIG.

Since the conveying apparatus according to an embodiment of the present disclosure can convey the printing paper S in a direction opposite to the conveying direction during a predetermined condition after the paper S is picked up, it is possible to prevent the feeding of the paper with a simple configuration. Can be.

In addition, since the conveying apparatus according to the embodiment of the present disclosure rotates both the conveying roller 40 and the feeding roller 30 in the reverse direction of the conveying direction for a predetermined time in order to separate the sheet S, the sheet S may be formed. Since it is possible to improve the separation ability between the), it is possible to improve the operation rate of the image forming apparatus 100 according to an embodiment of the present disclosure.

FIG. 11 is a view for explaining the conveyance of paper having different transfer start time points when the conveying apparatus according to one embodiment of the present disclosure performs an operation of rotating the reverse direction only for the paper passing through the sensor for a predetermined time.

In the above, the conveying apparatus 1 which performs the operation | movement which reversely conveys the sheet | seat S for every conveyance period was demonstrated, regardless of the position of the front end of the sheet | seat S which is started conveying, in order to improve the inter-sheet separation performance.

The processor 140 of the conveying apparatus 1 disclosed in FIG. 11 may control the conveying apparatus 1 such that the sheet is conveyed backward only when the front end of the sheet S, which starts conveying, passes through the sensor 50. That is, when the picked-up paper S is not detected by the sensor 50, the transfer device 1 does not perform an operation of reversely feeding the paper S in a direction opposite to the feeding direction, and picked-up paper S Only when is detected by the sensor 50 can the paper (S) in the reverse direction of the transfer direction.

According to the conveying apparatus 1 shown in FIG. 11, only when the front end of the paper S reaches the sensor 50, the paper S is conveyed in the opposite direction to the conveying direction, and the front end of the paper S is the sensor. In the case of not reaching 50, the paper S is conveyed in the conveying direction.

Referring to FIG. 11, P10 represents a conveying process of the paper S when the leading end of the picked up paper S is located immediately downstream of the pickup roller 20 and the transfer nip (P10), and P20 represents the paper S ) Indicates the transfer process of the paper S in the case where the tip of the paper is located between the paper feed roller 30 and the conveying roller 40 (P20), and P30 is when the leading edge of the paper is located immediately upstream of the sensor 50 ( The conveyance process of the sheet | seat S of P30 is shown. P40 shows the transfer process of the paper S in the case where the front end of the picked-up paper S has passed through the sensor 50 (P40).

First, when the tip of the paper S is located downstream of the sensor 50 (P10, P20), the operation of the conveying apparatus 1 will be described.

When the tip of the picked-up paper S is positioned before passing through the sensor 50 (P10, P20), the paper S is transferred in the conveying direction. The detailed operation of conveying the paper S in the conveying direction is omitted since it has been described with reference to FIGS. 7A and 9A.

The operation of the conveying apparatus 1 when the front end of the sheet S has passed through the sensor 50 (P30, P40) will be described. The paper S, which is likely to be largely fed, which is a friction force between the papers, has a high feed rate when the leading edge of the paper passes through the sensor 50 at the start of the feeding. Accordingly, in the conveying apparatus 1 according to the exemplary embodiment of the present disclosure, when the sheet S is detected by the sensor 50, the sheet S is conveyed backward.

When the leading end of the picked up paper S is positioned in the state of passing through the sensor 50, the feeder 1 reverses the paper S until the leading edge of the paper S is located downstream of the sensor 50. Can be transferred. The feeding roller 30 and the conveying roller 40 may be reversely rotated in the opposite direction to the conveying direction until the sensor 50 is turned off. The detailed operation of conveying the paper S in the direction opposite to the conveying direction until the sensor 50 is turned off has been described with reference to FIGS. 7B and 9B and thus will be omitted.

The paper S, which has been conveyed back until the sensor 50 is turned off, is conveyed back for a predetermined time T1, similar to the paper S when the leading edge of the paper S is located downstream of the sensor 50. After stopping for a predetermined time (T2), the sensor 50 feeds in the conveying direction until the paper (S) is detected, and after stopping for a predetermined time (T34) again when the paper is to be transferred to the print engine It is conveyed in the conveying direction again toward 110. The detailed operation of conveying the paper S in the conveying direction is omitted since it has been described with reference to FIGS. 7A and 9A.

Unlike the transfer device disclosed in FIG. 4, which reversely transfers all papers to be conveyed, when the paper S is transferred back only when the leading edge of the paper S passes through the sensor 50 at the start of the transfer, the time for transferring the paper It can be shortened and can be applied to high speed machine. In addition, the number of operations for backward conveying the paper can be reduced, so that the life of the parts constituting the conveying device 1 can be increased.

12 is a flowchart of a paper conveying method in the image forming apparatus of the present disclosure.

Referring to FIG. 12, first, the printing paper S picked up using the paper feed roller 30 and the conveying roller 40 is provided to the print engine 110 (S1210). Specifically, after the start of the image, the printing paper S loaded in the cassette 10 is picked up, and the picked printing paper S is moved in the transfer path.

After the printing paper S is picked up, every sheet of printing paper to be conveyed for a predetermined time is transferred in a direction opposite to the feeding direction (S1220). In the step of back conveying the printing paper S, both the conveying roller 40 and the paper feeding roller 30 rotate in the opposite directions to the conveying direction. The paper S back-fed for a predetermined time is separated from the paper feeding roller 30 and the conveying roller 40 by the back-feeding, and is conveyed back while being separated between the plurality of papers.

Then, the back conveyed printing paper S is conveyed in the conveying direction (S1230). Both the conveyance roller 40 and the feed roller 30 rotate in the conveyance direction.

Therefore, the paper conveying method of the present disclosure can fundamentally separate paper into the image forming apparatus to prevent feeding. The paper conveying method as shown in FIG. 12 may be executed on the image forming apparatus having the configuration of FIG. 1 or 2, or may be executed on the image forming apparatus having other configurations.

Meanwhile, the above-described paper conveying method may be implemented in a program and provided to the display device. In particular, the program including the paper conveying method may be stored and provided in a non-transitory computer readable medium.

The non-transitory readable medium refers to a medium that stores data semi-permanently and is readable by a device, not a medium storing data for a short time such as a register, a cache, a memory, and the like. Specifically, the various applications or programs described above may be stored and provided in a non-transitory readable medium such as a CD, a DVD, a hard disk, a Blu-ray disk, a USB, a memory card, a ROM, or the like.

While preferred embodiments of the present disclosure have been illustrated and described, the present disclosure is not limited to the above-described specific embodiments, and the disclosure belongs in the art without departing from the gist of the present disclosure as claimed in the claims. Various modifications can be made by those skilled in the art, and such changes are within the scope of the claims.

1: transfer device 10: cassette
20: pickup roller 30: paper feed roller
40: feed roller 100: image forming apparatus
110: print engine 140: processor

Claims (15)

In the image forming apparatus,
A print engine for forming an image on printing paper;
A conveying apparatus for conveying print paper to the print engine by using a feed roller and a conveying roller provided to face the feed roller; And
And a processor for controlling the conveying apparatus to convey the print sheet in a direction opposite to a conveying direction during a predetermined condition after the print sheet is picked up.
The processor,
And the conveying roller so as to rotate the conveying roller and the sheet feeding roller in the reverse direction of the conveying direction for a predetermined time to separate the printing sheet. The method of claim 1,
The processor,
And the conveying apparatus controls the conveying apparatus to reverse convey the printing sheet passing between the conveying roller and the sheet feeding roller in a direction opposite to the conveying direction at every feed cycle of the printing sheet. The method of claim 1,
The processor,
And the transfer apparatus controls the transfer apparatus to transfer the printing paper conveyed in the direction opposite to the transfer direction for the preset time again in the transfer direction. The method of claim 1,
The transfer device,
A sensor positioned in front of the paper feed roller and the conveying roller and configured to sense the printing paper;
The processor,
And a printing operation is executed to control the degree of reverse rotation of the conveying roller and the feed roller in a direction of conveying according to whether the sensor outputs a detection signal. The method of claim 4, wherein
The processor,
And if the printing sheet is not detected by the sensor, controlling the conveying device so that both the conveying roller and the sheet feeding roller rotate in the reverse direction of the conveying direction for the predetermined time. The method of claim 5,
The processor,
When the printing paper is detected by the sensor, both the conveying roller and the paper feeding roller are rotated in the reverse direction of the conveying direction until the printing paper is not detected by the sensor, and then the conveying roller for the predetermined time. And the feed roller so that the feed roller both rotates in the reverse direction of the feed direction. The method of claim 5,
The processor,
The conveying apparatus is controlled to convey the printing paper conveyed in the reverse direction of the conveying direction for the predetermined time until the sensing by the sensor, and to convey the printing sheet in the conveying direction after stopping for a predetermined time. An image forming apparatus. The method of claim 5,
The processor,
If the printing paper is not detected by the sensor, the feeding roller and the conveying roller are controlled to rotate in the conveying direction,
When the printing paper is detected by the sensor, both the conveying roller and the paper feeding roller are rotated in the reverse direction of the conveying direction until the printing paper is not detected by the sensor, and then during the predetermined time. And the conveying roller and the sheet feeding roller control the conveying device so as to rotate in the reverse direction of the conveying direction. The method of claim 1,
The transfer device,
A pickup roller for picking up printing paper loaded in the cassette;
A paper feed roller for transferring the printing paper picked up by the pickup roller in the transport direction;
A conveying roller installed to face the feeding roller;
A feeding motor for rotating the feeding roller, the conveying roller, and the pickup roller;
A feeding clutch selectively transferring the rotational force of the feeding motor to the feeding roller; And
And a pickup clutch for selectively transmitting the rotational force of the paper feed motor to the pickup roller. The method of claim 9,
The processor,
And a printing clutch to control the paper feed clutch to drive the paper feed motor and to prevent the rotational force of the paper feed motor from being transmitted to the paper feed roller for the predetermined time when a print job is executed. The method of claim 10,
The processor,
And the pick-up clutch to block the rotational force of the paper feed motor from being transmitted to the pick-up roller for the preset time. The method of claim 1,
The transfer device,
A pickup roller for picking up printing paper loaded in the cassette;
A paper feed roller for transferring the printing paper picked up by the pickup roller in the transport direction;
A conveying roller installed to face the feeding roller;
A feeding motor for rotating the feeding roller and the pickup roller;
A conveying motor for rotating the conveying roller; And
And a pickup clutch for selectively transmitting the rotational force of the conveying motor to the pickup roller. The method of claim 12,
The processor,
And when the print job is executed, driving the feed motor in reverse rotation for the preset time, and controlling the pickup clutch to block transmission of the rotational force of the transfer motor to the pickup roller for the preset time. In the transfer control method in the image forming apparatus,
Providing the print engine with the printing paper picked up using a paper feed roller and a conveyance roller installed to face the paper feed roller;
Backfeeding each sheet of paper conveyed for a predetermined time after the printing paper is picked up in a direction opposite to a conveying direction; And
Conveying the back conveyed print paper back to the conveying direction; and
The reverse feed step,
Both the conveying roller and the sheet feeding roller rotate in a direction opposite to the conveying direction. The method of claim 14,
The reverse feed step,
The conveyance control method in which both the said conveyance roller and the said feed roller rotate in the direction opposite to the said conveyance direction every conveyance period of printing paper.

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