WO2023069150A1

WO2023069150A1 - Post-processing apparatus comprising a pressing member

Info

Publication number: WO2023069150A1
Application number: PCT/US2022/028685
Authority: WO
Inventors: Taehong KIM; JoongHyun Kim; Sinkyu KANG
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2021-10-22
Filing date: 2022-05-11
Publication date: 2023-04-27
Also published as: KR20230057815A

Abstract

An example post-processing apparatus includes a tray (400) to load at least one print medium thereon, and a folding device (200) provided adjacent to the tray and a pressing member (100). The folding device is to fold the at least one print medium. The pressing member is to, based on a second print medium being transferred to the tray on which at least one first print medium is already loaded, move between a first position to press the first print medium loaded on the tray and a second position to allow the second print medium to be loaded onto the tray.

Description

POST-PROCESSING APPARATUS COMPRISING A PRESSING MEMBER

BACKGROUND

[0001] A post-processing apparatus may refer to an apparatus that may be connected to an image forming apparatus such as a printer or a multifunction printer to receive image-formed print media from the image forming apparatus to perform various kinds of post-processing on the print media.

[0002] Such a post-processing apparatus can perform a function such as an alignment operation to align the print media, a punching operation to form binding holes in the print media, a stapling operation to bind a plurality of print media together through a stapler, a folding operation to fold a plurality of print media at the centers thereof in a booklet form, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Various examples will be described below by referring to the following figures.

[0004] FIG. 1 is a conceptual diagram schematically illustrating an image forming system according to an example.

[0005] FIG. 2 is a block diagram showing an inlet roller, an alignment part, a booklet part, and a control part of a post-processing apparatus shown in FIG. 1 according to an example.

[0006] FIG. 3 is a perspective view of the booklet part shown in FIG. 1 according to an example.

[0007] FIG. 4 is a partial longitudinal sectional view of the booklet part shown in FIG. 3 according to an example.

[0008] FIG. 5 is a partial perspective view of a folding guide and a folding device shown in FIG. 4 according to an example.

[0009] FIG. 6 is an enlarged view of part A in FIG. 4 according to an example.

[0010] FIG. 7 is a view showing a state in which the folding guide of FIG. 6 presses a print medium according to an example.

[0011] FIG. 8 is a partial longitudinal sectional view of a booklet part according to an example.

[0012] FIG. 9 is an enlarged view of part B in FIG. 8 according to an example.

[0013] FIG. 10 is a view showing a state in which the paddle pusher of FIG. 9 presses the print medium according to an example.

DETAILED DESCRIPTION

[0014] Hereinafter, examples will be described with reference to the accompanying drawings.

[0015] A component that is described as “connected”, “supported”, or “seated” to another component may be understood as being directly connected, supported, or seated to the latter component or that a third component may be interposed between the two components.

[0016] Certain terms used in the present specification are to describe various examples without limiting the disclosure. An expression used in the singular encompasses the expression of the plural, unless it has a clearly different meaning in the context.

[0017] The terms used herein, including ordinal numbers such as “first” and “second” may be used to describe, and not to limit, various components. The terms are to distinguish the components from one another.

[0018] The meaning of “comprising” or “including” refers to a specific characteristic, region, integer, operation, action, element, and/or component, and use of either term is not to limit the existence or addition of another specific characteristic, region, integer, operation, action, element, component, and/or group.

[0019] In addition, expressions regarding a direction in the description are based on the illustration in the drawings. It is mentioned in advance that if the direction of the corresponding object is changed, the object may be depicted differently. In the specification, the thickness direction may be the x-axis direction in FIGS. 4 and 8, and the length direction may be the y-axis direction in FIGS. 4 and 8. Further, the width direction may be a direction perpendicular to the x-axis direction and the y-axis direction in FIGS. 4 and 8.

[0020] Hereinafter, an example of an image forming system 1 will be described with reference to the drawings.

[0021] Referring to FIG. 1 , the image forming system 1 may generate, print, receive, and transmit image data and may post-process image-formed print media and provide the print media to a user in various forms. This image forming system 1 may include an image forming apparatus 2 and a post-processing apparatus 3.

[0022] The image forming apparatus 2 may form an image on a print medium by various printing methods such as an electrophotographic method, an inkjet method, a thermal transfer method, a thermal sublimation method, and the like. Such an image forming apparatus 2 may deliver an image-formed print medium to the post-processing apparatus 3.

[0023] Referring to FIGS. 1 and 2, the post-processing apparatus 3 may receive the image-formed print medium from the image forming apparatus 2 and may perform post-processing on the print medium. For example, the postprocessing apparatus 3 may provide print media to the user without changing the received print media or may provide print media based on performing operations such as aligning, punching, folding, stapling, and the like. In various examples, the print media may be provided in forms such as papers, paperboards, overhead project films (OHP), and the like. In addition, the post-processing apparatus 3 may be integrally provided within the image forming apparatus 2 or may be provided as a separate apparatus so as to be separable from the image forming apparatus 2. The post-processing apparatus 3 may include a body part 10, an inlet roller 20, a tray part 30, an alignment part 40, a booklet part 50, and a control part 60.

[0024] The body part 10 may support the inlet roller 20, the tray part 30, the alignment part 40, and the booklet part 50. The body part 10 may be connected to the image forming apparatus 2 and may be supported by the image forming apparatus 2. [0025] The inlet roller 20 may transfer or feed the print medium received from the image forming apparatus 2 to the tray part 30, the alignment part 40, and the booklet part 50.

[0026] The tray part 30 may provide the user with the print medium processed or aligned in the alignment part 40 and the booklet part 50. The tray part 30 may include a top tray 31 , a main tray 32, and a booklet tray 33.

[0027] If there is no operation to be performed for the print medium, the top tray 31 may receive the print medium fed from the inlet roller 20 without going through the alignment part 40 and the print medium may be provided to the user. [0028] The main tray 32 may provide a print medium subjected to a punching operation or a stapling operation to the user based on the punching operation or the stapling operation being performed for the print medium. The main tray 32 may receive a print medium from a puncher (not shown) or a stapler (not shown).

[0029] The booklet tray 33 may provide a print medium subjected to a booklet operation to the user based on the booklet operation being performed for the print medium. The booklet tray 33 may receive a print medium from the booklet part 50.

[0030] The alignment part 40 may align a plurality of print media, on which images are formed in the image forming apparatus 2, in a preset arrangement pattern. For example, the alignment part 40 may align the plurality of print media in the longitudinal direction and the width direction.

[0031] The booklet part 50 may process print media into a booklet form by stapling and folding the print media or by folding the print media without stapling. For example, the booklet part 50 may provide various types of booklets according to a user's input. Further, the booklet part 50 may align the print media at a preset position before folding the print media. The booklet part 50 may include a pressing member 100, a folding device 200, a paper feeding device 300, a tray 400, and a driving module 500.

[0032] Referring to FIGS. 3 and 4, the pressing member 100 may press the print media loaded on the tray 400 based on a print medium being fed to the tray 400 in a state in which the print media are already loaded on the tray 400. The pressing member 100 may be movably provided between a first position and a second position. The first position of the pressing member 100 refers to a position at which the pressing member 100 presses the print media loaded on the tray 400. For example, the pressing member 100 presses the print media loaded on the tray 400 in order to secure a space in which a print medium is fed to the tray 400 at the first position. In this case, the print media loaded on the tray 400 are pressed by the pressing member 100, and a space for accommodating a print medium is secured in the tray 400. In other words, the print medium fed to the tray 400 may be loaded on the tray 400 without interfering with the print media loaded on the tray 400.

[0033] The second position of the pressing member 100 refers to a position at which a print medium is allowed to be loaded on the tray 400. For example, the pressing member 100 may be spaced apart from the print media loaded on the tray 400 at the second position. In this case, a print medium may be fed to the tray 400 and may be loaded on the tray 400. In a situation in which the pressing member 100 moves between the first position and the second position, the print media loaded on the tray 400 may be kept pressed for a predetermined time. In other words, even if the pressing member 100 deviates from the first position, the inner space of the tray 400 may be maintained so that a print medium can be fed to and loaded on the tray 400.

[0034] The print media preloaded on the tray 400 may be understood as the print media preloaded on the tray 400 before a print medium is fed to the tray 400. One print medium may be fed to the tray 400 at a time, and the pressing member 100 may perform a pressing operation each time that one print medium is fed to the tray 400. In other words, the pressing member 100 may move between the second position and the first position each time that one print medium is fed to the tray 400. The pressing member 100 may return to the second position.

[0035] The pressing member 100 may include a folding guide 110, a paddle 120, and a shaft 130. The folding guide 110 may prevent the print medium fed toward the tray 400 from interfering with the folding device 200. For example, the folding guide 110 may prevent the print medium from coming into contact with a first folding roller 210 and a second folding roller 220, examples of which will be described later. In this case, it is possible to prevent the print medium from being aligned out of the position set on the tray 400 due to the friction with the first folding roller 210 and the second folding roller 220.

[0036] In addition, the folding guide 110 may press the print media loaded on the tray 400 and may allow a print medium to be fed toward the tray 400. The folding guide 110 may be located at either the first position or the second position. [0037] The first position of the folding guide 110 refers to a position where the folding guide 110 presses the print media loaded on the tray 400. For example, referring to FIG. 7, based on the folding guide 110 being located at the first position, the folding guide 110 may press the print media loaded on the tray 400. In this case, the print media loaded on the tray 400 are pressed by the folding guide 110, and a space for accommodating a print medium is secured in the tray 400. In addition, the folding guide 110 located at the first position may be arranged to be inclined toward the tray 400. In this case, one side of the folding guide 110 may press the print media loaded on the tray 400, and the other side of the folding guide 110 may be spaced apart from the print media loaded on the tray 400.

[0038] Referring to FIGS. 5 and 6, the second position of the folding guide 110 refers to a position at which the folding guide 110 allows the loading of a print medium into the tray 400. In addition, the second position of the folding guide 110 may be a position at which the folding device 200 located at the first position is rotated by a set angle. For example, the folding guide 110 may be rotated by a set angle from the first position so as to be located at the second position and the folding guide 110 located at the second position may be spaced apart from the print media loaded on the tray 400. In this case, a space into which a print medium can be fed is formed between the print media loaded on the tray 400 and the folding guide 110. In addition, the folding guide 110 located at the second position may be arranged to be parallel to the tray 400.

[0039] The folding guide 110 may be rotated by the driving module 500. For example, the folding guide 110 may be rotated between the first position and the second position by the driving module 500. In addition, the folding guide 110 may be rotated while covering the outer circumferential surface of the first folding roller 210. In other words, the folding guide 110 may be rotated along the outer circumferential surface of the first folding roller 210. The folding guide 110 may be arranged adjacent to the first folding roller 210. The folding guide 110 may be located coaxially with the first folding roller 210 and may be rotated independently of the first folding roller 210. For example, the folding guide 110 may be connected to the driving module 500 through a gear. In an example, the folding guide 110 and the first folding roller 210 may be rotated by different driving modules 500. The folding guide 110 may include a guide body 111 and a guide sheet 112.

[0040] The guide body 111 may be supported by the driving module 500 and rotated by the driving module 500. For example, the guide body 111 may be arranged to cover the outer circumferential surface of the first folding roller 210 based on the folding guide 110 being located at the first position and the second position. In this case, the print medium fed toward the tray 400 by the guide body 111 is prevented from interfering with the first folding roller 210. In addition, the print medium fed toward the tray 400 by the guide body 111 is guided toward the tray 400 without making contact with the first folding roller 210. The guide body 111 may include a material having rigidity and a small frictional force. For example, the guide body 111 may include a plastic material. In addition, the guide body 111 may support the guide sheet 112. The guide body 111 may extend along the width direction.

[0041] The guide sheet 112 may be supported by the guide body 111 to rotate together with the guide body 111. For example, the guide sheet 112 may press the print media loaded on the tray 400 based on the folding guide 110 being located at the first position. In this case, the guide sheet 112 presses the print media while being inclined with respect to the tray 400. Further, based on the guide sheet 112 being located at the second position, the guide sheet 112 may be spaced apart from the print media loaded on the tray 400. The guide sheet 112 may include a flexible material so that it can be bent based on the print media being pressed. The guide sheet 112 including a flexible material in this way can be prevented from pressing the print media with an excessive pressure. The guide sheet 112 may be spaced apart from the print media again after pressing the print media. [0042] The paddle 120 may transfer or feed the print medium from a booklet inlet roller 310 toward the tray 400. A plurality of such paddles 120 may be provided and may be spaced apart from each other along the shaft 130. In addition, the paddle 120 may include a paddle housing 121 and a feeding member 122.

[0043] The paddle housing 121 may support the feeding member 122. The paddle housing 121 may be supported on the shaft 130 and may be rotated together with the shaft 130. In this case, the axis of rotation of the paddle housing 121 may be the shaft 130.

[0044] The feeding member 122 may be rotated together with the paddle housing 121 and may selectively make contact with the print medium. In addition, the feeding member 122 may transfer or feed the print medium toward the tray 400. For example, the feeding member 122 may have a frictional force based on being in contact with the print medium and may transfer or feed the print medium by this frictional force. As an example, the feeding member 122 may include a rubber material having a high frictional force based on being in contact with the print medium to feed the print medium. A plurality of the feeding members 122 may be provided and the plurality of feeding members 122 may protrude from the paddle housing 121 in opposite directions.

[0045] The folding device 200 may fold the print media. The folding apparatus 200 may fold a plurality of print media loaded on the tray 400. For example, the folding apparatus 200 may fold the print media in half through V- folding and may also perform a C-folding operation or the like. The folding device 200 may include a first folding roller 210, a second folding roller 220, and a folding knife 230.

[0046] The first folding roller 210 and the second folding roller 220 may transfer or feed the print medium which has been moved to a position between the first folding roller 210 and the second folding roller 220. For example, the first folding roller 210 and the second folding roller 220 may be spaced apart from each other to form a gap between the first folding roller 210 and the second folding roller 220. In this case, the plurality of print media may be fed through the gap formed between the first folding roller 210 and the second folding roller 220 while being folded. In addition, the first folding roller 210 and the second folding roller 220 may rotate in opposite directions.

[0047] The folding knife 230 may press the print media so that the print media can be folded. Further, the folding knife 230 may be operated to move toward and away from the gap between the first folding roller 210 and the second folding roller 220. For example, the folding knife 230 may fold the print media by pressing the middle portions of the print media and may transfer or feed the folded print media toward the gap formed between the first folding roller 210 and the second folding roller 220. In this case, the folded print media are fed to between the first folding roller 210 and the second folding roller 220. The folding knife 230 may be arranged adjacent to the first folding roller 210 and the second folding roller 220.

[0048] The paper feeding device 300 may transfer or feed a print medium toward the tray 400. The paper feeding device 300 may include the booklet inlet roller 310 and an inlet guide 320.

[0049] The booklet inlet roller 310 may receive a print medium from the inlet roller 20 and may transfer or feed the print medium to the tray 400.

[0050] The inlet guide 320 may guide the movement of the print medium fed by the booklet inlet roller 310.

[0051] The tray 400 may accommodate the print media. The print media may be sequentially stacked on the tray 400 along the thickness direction of the tray 400. In addition, a paper alignment end 410 for supporting the print media may be formed on one side of the tray 400. The paper alignment end 410 may prevent the print media fed toward the tray 400 from leaving the tray 400. In addition, the print medium fed to the tray 400 may be aligned at a preset position in the longitudinal direction by the paper alignment end 410.

[0052] The driving module 500 may provide power to rotate the first folding roller 210 and the second folding roller 220 and may provide power to rotate the folding guide 110. In addition, the driving module 500 may provide power to move the folding knife 230 forward and backward. For example, the driving module 500 may include a plurality of driving units which may be spaced apart from each other to constitute one assembly. In addition, each of the driving units may provide power to the folding guide 110, the first folding roller 210, the second folding roller 220, and the folding knife 230.

[0053] The control part 60 may control the inlet roller 20 and the driving module 500. The control part 60 may be realized by a calculation device including a microprocessor, a measurement device such as a sensor or the like, and a memory.

[0054] Hereinafter, example operations and effects of the post-processing apparatus 3 will be described.

[0055] The control part 60 may control the inlet roller 20 to feed a print medium toward the paper feeding device 300 based on an image-formed print medium being fed from the image forming apparatus 2. Based on the print medium being fed to the booklet inlet roller 310, the paper feeding device 300 may transfer or feed the print medium to the tray 400. Before the print medium is fed to the tray 400, the folding guide 110 may be rotated to be located at the first position. In this case, the print media loaded on the tray 400 is pressed by the folding guide 110 so that a space for loading a print medium can be secured in the tray 400.

[0056] Thereafter, the folding guide 110 located at the first position may be rotated to be located at the second position based on the print medium being fed to the tray 400. In this case, the print medium fed to the tray 400 may be guided to the tray 400 without making contact with the first folding roller 210 and the second folding roller 220. In addition, the print medium may be prevented by the folding guide 110 from interfering with the first folding roller 210 or the second folding roller 220.

[0057] Based on a plurality of print media being fed from the image forming apparatus 2 to the post-processing apparatus 3, the post-processing apparatus 3 may perform the above-described processes for each print medium.

[0058] In an example, the paddle 120 may further include a paddle pusher 123 and an elastic member 124. Hereinafter, an example will be described with further reference to FIGS. 8 to 10. In describing the example of FIGS. 8 to 10, differences from the above-described example are mainly described. The description and reference numerals of the above-described example are incorporated here by reference.

[0059] Referring to FIGS. 8 to 10, the paddle 120 may transfer or feed a print medium toward the tray 400. Further, the paddle 120 may press the print media loaded on the tray 400 based on a print medium being fed to the tray 400 in a state in which the print media are already loaded on the tray 400. For example, the paddle 120 presses the print media loaded on the tray 400 in order to secure a space to which a print medium is to be fed. In this case, the print media loaded on the tray 400 are pressed by the paddle 120, and a space for accommodating the print medium is secured in the tray 400. In other words, the print medium fed to the tray 400 may be loaded on the tray 400 without interfering with the print media loaded on the tray 400. In addition, the print medium may be fed to and loaded on the tray 400 by the paddle 120. The paddle 120 may include a paddle housing 121 , a feeding member 122, a paddle pusher 123, and an elastic member 124.

[0060] The paddle pusher 123 may press the print media loaded on the tray 400. For example, based on the paddle pusher 123 pressing the print media loaded on the tray 400, a space in which a print medium is loaded may be secured in the tray 400. In addition, the paddle pusher 123 may allow the print medium to be fed toward the tray 400. The paddle pusher 123 may be located at either a first position or a second position.

[0061] Referring to FIG. 10, the first position of the paddle pusher 123 refers to a position where the paddle pusher 123 presses the print media loaded on the tray 400. In this case, the paddle pusher 123 may press the print media, and the elastic member 124 may be elastically compressed. In addition, the print media loaded on the tray 400 may be pressed by the paddle pusher 123, and a space to which a print medium is fed may be secured in the tray 400. In this regard, the first position of the paddle pusher 123 may cover a range from a position at which the paddle pusher 123 starts pressing the print media to a position at which the paddle pusher 123 moves away from the print media. In other words, the first position of the paddle pusher 123 may refer to a range from a position at which the elastic member 124 is initially compressed to a position at which the compression is released. [0062] Referring further to FIG. 9, the second position of the paddle pusher 123 refers to a position where the paddle pusher 123 is spaced apart from the print media loaded on the tray 400. In this case, the paddle pusher 123 may be spaced apart from the print media, and the elastic compression of the elastic member 124 may be released. In addition, the paddle pusher 123 at the second position may be located at a position spaced further apart from the rotation center of the paddle 120 than the paddle pusher 123 at the first position.

[0063] Based on the paddle pusher 123 located at the first position being rotated to the second position, a space to which a print medium is fed and stacked is formed in the tray 400, whereby the print medium can be fed to the tray 400 by the feeding member 122. The paddle pusher 123 may be connected to the paddle housing 121 through the elastic member 124 and may be rotated together with the paddle housing 121.

[0064] In addition, at least a portion of the paddle pusher 123 may be made of a material having a low frictional force with respect to a print medium in order to prevent the loaded print medium from being fed by the rotation of the paddle pusher 123 based on the loaded print medium being pressed by the paddle pusher 123. For example, the paddle pusher 123 may have a smaller coefficient of friction than that of the feeding member 122. In an example, the paddle pusher 123 may include a plastic material.

[0065] The elastic member 124 may connect the paddle housing 121 and the paddle pusher 123 to each other. In addition, the elastic member 124 may prevent the paddle pusher 123 from excessively pressing the print media loaded on the tray 400. For example, the elastic member 124 may be compressed based on the paddle pusher 123 pressing the print media. The elastic member 124 may be, for example, a spring.

[0066] Hereinafter, operations of the post-processing apparatus 3 according to another example will be described.

[0067] Based on a print medium being fed to the booklet inlet roller 310, the paper feeding device 300 may transfer or feed the print medium to the tray 400. Further, before the print medium is fed to the tray 400, the paddle 120 may be rotated to be located at the first position. In this case, the print media loaded on the tray 400 may be pressed by the paddle pusher 123, and a space for loading a print medium may be secured in the tray 400.

[0068] Thereafter, the paddle pusher 123 may be rotated to be located at the second position based on the print medium being fed to the tray 400. In this case, the feeding member 122 may transfer or feed the print medium toward the tray 400. The paddle 120 may be rotated each time that a print medium is fed, and the above operation may be repeated.

[0069] As such, the post-processing apparatus 3 may secure a space in the tray 400 by pressing the print media loaded on the tray 400 based on a print medium being fed to the tray 400. In this case, it is possible to prevent the print medium fed to the tray 400 and the loaded print media from interfering with each other so that the print media are not aligned at a preset position.

[0070] While examples of the present disclosure have been described, the present disclosure is not limited thereto and should be construed as having the widest scope within the technical spirit disclosed in the present specification. The present disclosure may be implemented in a form that is not included in the above described examples by combining or replacing the disclosed examples, however, it also does not depart from the scope of the present disclosure. In addition, it is apparent that the disclosed examples may be changed or modified based on the present specification, and thus, such changes or modifications fall within the scope of the present disclosure.

Claims

WHAT IS CLAIMED IS:

1. A post-processing apparatus, comprising: a tray to load at least one print medium thereon; a folding device provided adjacent to the tray to fold the at least one print medium; and a pressing member to, based on a second print medium being transferred to the tray on which at least one first print medium is already loaded, move between a first position to press the first print medium loaded on the tray and a second position to allow the second print medium to be loaded onto the tray.

2. The apparatus of claim 1 , wherein the pressing member comprises a folding guide to prevent the second print medium being transferred toward the tray from interfering with the folding device, wherein, based on the pressing member being at the first position, the folding guide is inclined toward the tray to press the first print medium loaded on the tray, and wherein, based on the pressing member being at the second position, the folding guide is rotated by a predetermined angle from the first position so as to be spaced apart from the first print medium loaded on the tray.

3. The apparatus of claim 2, wherein the folding device includes a plurality of folding rollers spaced apart from each other to transfer the at least one print medium therebetween, and wherein the folding guide is arranged to surround at least one of the folding rollers at the first position and the second position.

4. The apparatus of claim 2, wherein the folding guide further comprises: a guide body rotatable independently of the folding device; and a guide sheet supported on the guide body to be rotatable correspondingly to the guide body, wherein the guide sheet is to press the first print medium based on the folding guide being located at the first position and to be spaced apart from the first print medium loaded on the tray based on the folding guide being located at the second position.

5. The apparatus of claim 4, wherein the guide body has rigidity, and wherein at least part of the guide sheet includes a flexible material.

6. The apparatus of claim 1 , wherein the pressing member comprises a paddle to transfer the second print medium toward the tray, the paddle comprising: a paddle pusher to press the first print medium loaded on the tray; and an elastic member to be compressed based on the paddle pusher pressing the first print medium, wherein, based on the pressing member being at the first position, the elastic member is elastically compressed so that the paddle pusher presses the first print medium loaded on the tray, and wherein, based on the pressing member being at the second position, the elastic member is released from elastic compression so that the paddle pusher at the second position is spaced further apart from a rotation center of the paddle than the paddle pusher at the first position.

7. The apparatus of claim 6, wherein the paddle is to rotate about an axis of rotation, and wherein the paddle pusher is to move from one of the first position and the second position to the other position correspondingly to rotation of the paddle.

8. The apparatus of claim 6, wherein the paddle further comprises: 16 a paddle housing to support the paddle pusher; and a feeding member protruding from the paddle housing to rotate correspondingly to the paddle housing to selectively make contact with the second print medium, and wherein the paddle pusher has a smaller coefficient of friction than that of the feeding member.

9. A post-processing apparatus, comprising: a tray to load at least one print medium thereon; a folding device provided adjacent to the tray to fold the at least one print medium; and a folding guide to be located at a first position or a second position, the folding guide being, at the first position, inclined toward the tray to press the print medium loaded on the tray and, at the second position, rotated by a predetermined angle from the first position so as to be spaced apart from the print medium loaded on the tray.

10. The apparatus of claim 9, wherein the folding device includes a plurality of folding rollers spaced apart from each to transfer the at least one print medium therebetween, and wherein the folding guide is arranged to surround at least one of the folding rollers at the first position and the second position.

11 . The apparatus of claim 9, wherein the folding guide further comprises: a guide body rotatable independently of the folding device; and a guide sheet to be rotatable correspondingly to the guide body, and wherein the guide sheet is to press the print medium based on the folding guide being located at the first position and to be spaced apart from the print medium loaded on the tray based on the folding guide being located at the second position. 17

12. The apparatus of claim 11 , wherein the guide body has rigidity, and wherein the guide sheet includes a flexible material.

13. A post-processing apparatus, comprising: a tray to load at least one print medium thereon; a folding device provided adjacent to the tray to fold the at least one print medium; and a paddle to transfer the print medium toward the tray, the paddle comprising: a paddle pusher to press the print medium loaded on the tray; and an elastic member to be compressed based on the paddle pusher pressing the print medium, wherein the paddle is to be located at a first position or a second position, the elastic member being, at the first position, elastically compressed so that the paddle pusher presses the print medium loaded on the tray and, at the second position, released from elastic compression so that the paddle pusher at the second position is spaced further apart from a rotation center of the paddle than the paddle pusher at the first position.

14. The apparatus of claim 13, wherein the paddle is to rotate about an axis of rotation, and wherein the paddle pusher is to move from one of the first position and the second position to the other position correspondingly to rotation of the paddle.

15. The apparatus of claim 13, wherein the paddle further comprises: a paddle housing to support the paddle pusher; and a feeding member protruding from the paddle housing to rotate correspondingly to the paddle housing to selectively make contact with the print medium on the tray, and wherein the paddle pusher has a smaller coefficient of friction than that of 18 the feeding member.