Image forming system

Abstract

To reduce a cost of a sheet detection sensor in a paper ejection tray above a post-processing device movably mounted in a paper ejection space of an image forming apparatus.SOLUTION: There is provided an image formation system in which a post-processing device is mounted movably along a paper ejection direction in a paper ejection space of an image forming apparatus, and a sheet ejection tray for stacking sheets discharged from the image forming apparatus above the post-processing device is fixed to the image forming apparatus. A sheet detection sensor 90 that detects presence or absence of sheets on a sheet ejection tray includes: a first actuator 91 that is arranged on the sheet ejection tray side and includes a swing lever 913 that swings upon detecting a sheet; a second actuator 92 that is arranged on a side of the post-processing device and includes first and second blade members (pivoted members) 921 and 923 abut on the swing lever 913 when the post-processing device is positioned at first and second positions, respectively; and a photoelectric sensor 93 that detects a swing motion of the second actuator 92.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an image forming system in which a post-processing device is movably mounted in the paper discharge space of an image forming device, and in particular to a technology for detecting sheets in a discharge tray that stacks sheets discharged above the post-processing device without passing through the post-processing device. [Background technology]

[0002] Some image forming devices have an image forming unit and an image reading unit arranged vertically, and discharge the image-formed sheet into the space (internal space) between them (internal paper discharge type image forming device), and some devices allow a post-processing device to be added as an option by utilizing the internal space (paper discharge space) (for example, Patent Document 1).

[0003] When a post-processing device is installed in the body space, a separate transport path is provided for discharging sheets without post-processing, in addition to the transport path for aligning sheets and performing post-processing such as stapling, and the sheets are discharged to a paper output tray located above the post-processing device. This is because when post-processing is not performed, it is more rational to discharge the sheets directly onto the paper output tray without using the transport path of the post-processing device.

[0004] Such a paper output tray is installed above the post-processing device as an accessory when the optional post-processing device is installed, and therefore will be referred to below as an "additional paper output tray" to distinguish it from the paper output tray originally formed at the bottom of the internal space of the image forming device.

[0005] In addition, to make it easier for users or service personnel to clear the jam if a jam (paper jam) occurs between the sheet receiving inlet of the post-processing device and the sheet discharge outlet of the image forming device, rails are arranged parallel to the sheet discharge direction on the loading surface of the post-processing device in the internal space of the image forming device, and the post-processing device is configured to be able to move along the rails downstream in the discharge direction (in the direction in which the sheet receiving inlet of the post-processing device and the sheet discharge outlet of the image forming device move away from each other).

[0006] However, when an additional paper output tray is placed above the post-processing device mounted in the internal space as described above, there is a small gap between the additional paper output tray and the image reading unit above it, which means that the user cannot see the sheets output onto the additional paper output tray, and may forget to pick them up and leave them there for a long time.

[0007] To address this issue, it is desirable to provide a sheet detection sensor that detects sheets on the additional output tray, and when this detects that a sheet remains, to warn the user to collect the sheet, for example, by displaying a message on the display section of the operation panel or by turning on a dedicated lamp.

[0008] FIG. 7 is a perspective view showing the configuration of a sheet detection sensor 1000 that is generally used to detect the presence or absence of a sheet on a tray for placing sheets.

[0009] As shown in the figure, the sheet detection sensor 1000 comprises an actuator 1010 that physically detects the presence of a sheet and swings, and a photoelectric sensor 1014 that electrically detects the swinging action of the actuator 1010.

[0010] The actuator 1010 comprises a detection lever 1011 attached to one end of a rod member 1012 and a light blocking plate 1013 attached to the other end.

[0011] The photoelectric sensor 1014 is a so-called transmission type photoelectric sensor (photointerrupter) that includes a light emitting portion 1014a and a light receiving portion 1014b.

[0012] The actuator 1010 is pivotally supported by a bearing member provided on the back surface of the additional paper output tray, with the protrusion 1011a of the detection lever 1011 protruding above the sheet placement surface through a slit hole in the additional paper output tray.When even one sheet is placed on the additional paper output tray, the protrusion 1011a is pushed downward, causing the detection lever 1011 to swing in direction A, which causes the rod member 1012 to rotate in direction B and further causes the light shielding plate 1013 to swing in direction F.As a result, the obstruction to the detection light emitted from the light emitting element 1014a of the photoelectric sensor 1014 is removed, and the light receiving element 1014b receives the detection light and generates an ON signal.

[0013] In this type of sheet detection sensor 1000, the rotational torque due to the weight of the detection lever 1011 and the light shielding plate 1013 is balanced so that the actuator 1010 will swing even if it comes into slight contact with the detection lever 1011, and the swinging motion of the actuator 1010 is detected by a non-contact photoelectric sensor 1014, so that the sheet detection sensitivity is extremely high.

[0014] As described above, the actuator 1010 is attached to the additional discharge tray side, but the photoelectric sensor 1014 is installed on the post-processing device side. If the photoelectric sensor 1014 were to be provided in the image forming apparatus, it would be necessary to incorporate the photoelectric sensor 1014 in advance at the assembly stage of the image forming apparatus even though it is not known whether or not the post-processing device will be installed as an option, which would hinder reduction in the price of the image forming apparatus itself.

[0015] Furthermore, if the photoelectric sensor 1014 were to be provided on the additional discharge tray side, the additional discharge tray would need a bundle of lead wires (wire bundle) and a connector for connection to receive power from the post-processing device or image forming device and transmit a detection signal, which would be disadvantageous in terms of cost and would require the effort of handling the lead wires and checking the correct connection of the connector when installing the post-processing device. In particular, when connecting to the post-processing device with a wire bundle, it is necessary to leave some slack in the length of the wire bundle just to move the post-processing device for jam clearance, which would increase costs and would also look unsightly if the wire bundle were exposed to the outside.

[0016] Since the additional discharge tray is originally installed in conjunction with the installation of the post-processing device, it is reasonable to incorporate the photoelectric sensor 1014 and complete the wiring during the manufacturing stage of the post-processing device, and it can be said that this also reduces the burden on the worker when actually installing the post-processing device and additional discharge tray in the image forming device. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] Japanese Patent Application Publication No. 2019-32416 Summary of the Invention [Problem to be solved by the invention]

[0018] However, there are various types of post-processing for recording sheets discharged from an image forming apparatus, and if a user requests the addition of another post-processing device to further expand functionality, in order to meet that request, it is desirable to be able to move the post-processing device that was previously installed in a movably manner in the direction of sheet discharge, and then incorporate a post-processing device with expanded functions in the gap between the moved post-processing device and the sheet discharge outlet of the image forming apparatus (hereinafter, the post-processing device that was previously installed will be referred to as the "first post-processing device," and the post-processing device that is added later will be referred to as the "second post-processing device").

[0019] In this case, if the additional paper output tray were to be moved together with the first post-processing device, the distance from the sheet output outlet of the image forming device would increase, making it difficult to output sheets onto the additional paper output tray, so the additional paper output tray must be fixed to the image forming device.

[0020] On the other hand, as described above, the photoelectric sensor 1014 of the sheet detection sensor 1000 is installed on the first post-processing device side, so when the first post-processing device moves, the relative positions of the actuator 1010 of the sheet detection sensor 1000 and the photoelectric sensor 1014 change, and the sheet detection sensor 1000 is no longer able to function.

[0021] To solve this problem, it is conceivable to, for example, place separate photoelectric sensors at the position that detects the light shielding plate before the first post-processing device moves and at the position that detects the light shielding plate after the first post-processing device moves, or to change the installation position of the photoelectric sensor within the first post-processing device, but in the former case, material costs increase by the amount of the added photoelectric sensor, and in the latter case, there is the problem that it requires extra work to disassemble the first post-processing device, remove the photoelectric sensor, and then install it at the detection position after the device has moved. Note that the sensor that detects the swinging movement of the actuator and emits an electric signal is typically a photoelectric sensor as described above, but is not limited to this.

[0022] The present disclosure has been made in consideration of the above circumstances, and aims to provide an image forming system in which a post-processing device is movably mounted in the paper discharge space of an image forming device and which has an additional discharge tray for stacking sheets discharged above the post-processing device without passing through the post-processing device, and which is equipped with a sheet detection means that, even if it is necessary to move the mounted post-processing device, does not require the increase in cost burden of installing multiple sensors in different positions on the post-processing device in advance, or the trouble of removing the sensor and reattaching it to a different position. [Means for solving the problem]

[0023] In order to achieve the above-mentioned object, the image forming system of the present disclosure is an image forming system in which a post-processing device is mounted in a paper discharge space of the image forming device so that the post-processing device is movable along the paper discharge direction, wherein a paper discharge tray for loading sheets discharged from the image forming device above the post-processing device is fixed to the image forming device, and a detection means for detecting the presence or absence of a sheet on the paper discharge tray comprises a first actuator including a swing lever that swings upon detecting a sheet, a second actuator including first and second swingable members that abut against the swing lever when the post-processing device is located at a first and second position in the paper discharge direction, respectively, and a sensor that detects the swinging movement of the second actuator, wherein the first actuator is arranged in the paper discharge tray, and the second actuator and sensor are arranged in the post-processing device.

[0024] In one aspect of the present disclosure, the image forming apparatus includes an original reading unit disposed above an image forming unit, and the paper discharge space is provided between the image forming unit and the original reading unit.

[0025] In addition, one aspect of the present disclosure is that the image forming device includes a first transport path that discharges an image-formed sheet toward the post-processing device, a second transport path that discharges the sheet toward the paper output tray without passing through the post-processing device, and a switching means that switches between the first and second transport paths.

[0026] In addition, one aspect of the present disclosure is that the post-processing device can be moved to a second position downstream in the paper discharge direction from the first position, and another post-processing device can be installed between the sheet discharge outlet of the first transport path of the image forming device and the post-processing device.

[0027] In addition, one aspect of the present disclosure is such that the first and second oscillating members of the second actuator are arranged at a distance apart in a direction parallel to the movement direction of the after-treatment device, and the distance is the distance at which the first oscillating member abuts against the oscillating lever when the after-treatment device is in a first position, and the second oscillating member abuts against the oscillating lever when the after-treatment device is in a second position. [Effects of the Invention]

[0028] According to the configuration of the present disclosure, even if it is necessary to move the installed post-processing device, a single sensor provided in the post-processing device can easily detect whether or not there is a sheet on the discharge tray provided above the post-processing device, eliminating the need to install multiple sensors in different positions on the post-processing device in advance and the hassle of removing the sensor and reattaching it to another position. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 is a diagram showing the configuration of an image forming system in which a post-processing device is installed in the internal space of an MFP. [Figure 2] FIG. 2 is a perspective view showing the appearance of a post-processing device mounted on the MFP and an additional paper ejection tray disposed above the post-processing device. [Figure 3] FIG. 10 is a diagram showing a state in which another post-processing device is mounted in the image forming system. [Figure 4] 1 is a perspective view showing a configuration of a sheet detection sensor according to the present disclosure when a post-processing device is in a first position. [Figure 5] 10 is a diagram for explaining the mounting state of a second actuator and a photoelectric sensor in a sheet detection sensor for detecting the presence or absence of remaining sheets on an additional discharge tray in the present disclosure to a side plate member of a post-processing device. FIG. [Figure 6] (a) is a diagram showing the positional relationship between the first actuator and the second actuator of the sheet detection sensor when the post-processing device is in the first position, and (b) is a diagram showing the positional relationship between the first actuator and the second actuator after the post-processing device has moved to the second position. [Figure 7] FIG. 10 is a perspective view showing the configuration of a conventional sheet detection sensor. DETAILED DESCRIPTION OF THE INVENTION

[0030] Below, an embodiment of an image forming system equipped with a post-processing device according to the present disclosure will be described with reference to the drawings, taking as an example a case in which the image forming device is a multi-function peripheral (hereinafter referred to as "MFP") that can communicate with an external terminal via a network and has the functions of a scanner, copier, printer, and facsimile machine.

[0031] (1) Configuration of Image Forming System 100 FIG. 1 is a front view showing the appearance of an image forming system 100 according to the present embodiment.

[0032] As shown in the figure, the image forming system 100 is formed by combining an MFP 130 and a post-processing device 70.

[0033] The MFP 130 has a so-called internal paper discharge configuration, with a gap (internal space) DSP between the scanner 110 and the printer 120. When the MFP 130 is used alone, the internal space serves as the paper discharge space, but in this embodiment, the post-processing device 70 is mounted in this paper discharge space so that it can move in the X direction to form the image forming system 100.

[0034] The scanner 110 has an automatic document feeder (ADF) 40 arranged above the image reading unit 30, and the image of the document transported by the ADF 40 is read by the image reading unit 30 to generate image data.

[0035] The printer 120 includes an image forming unit 10 that forms an image on a recording sheet, and a paper feeding unit 20 that feeds recording sheets to the image forming unit 10.

[0036] The image forming unit 10 forms a toner image on a recording sheet fed from the paper feeding unit 20 based on image data obtained by reading an original image using the scanner 110 using an electrophotographic method, or based on image data in a print job received from an external terminal via a network, and then thermally fixes the image in the fixing unit.

[0037] The control unit 50 in the MFP 130 controls each unit of the scanner 110 and printer 120 based on instructions received from the operation panel 60 or instructions received from an external terminal via the network, to smoothly execute various processes such as document scan jobs, copy jobs, print jobs, and facsimile sending and receiving processes. It also communicates with a control unit (not shown) in the post-processing device 70 to execute post-processing of sheets on which images have been formed.

[0038] In this embodiment, the post-processing device 70 has a built-in staple unit that aligns and staples sheets discharged from the MFP 130, and the stapled sheet stack is discharged onto the post-processing paper output tray 71.

[0039] In the event that a jam occurs between the post-processing device 70 and the sheet discharge port 131 on the MFP 130 side, a rail 101 is arranged parallel to the sheet discharge direction along a rail arranged at the bottom of the internal space DSP of the MFP 130 to enable the user or serviceman to clear the jam or to enable the addition of an extended post-processing device, as described below, and the post-processing device 70 is configured to be able to move downstream in the discharge direction (X direction) along the rail 101 as needed.

[0040] The post-processing device 70 or the rail 101 is provided with a locking mechanism (not shown) for fixing the post-processing device 70 at a desired position.

[0041] An additional paper output tray 80 is disposed above the main body of post-processing device 70 for directly stacking recording sheets (hereinafter simply referred to as "sheets") that are discharged from MFP 130 without going through a post-processing route. This additional paper output tray 80 is fixed to the MFP 130 side, so that the position of the additional paper output tray 80 does not change even if post-processing device 70 moves.

[0042] The MFP 130 is equipped with a conveying path switching claw 14, and switches between an upper conveying path 12 (second conveying path) for discharging sheets on which images have been formed in the image forming unit 10 and conveyed via the conveying path 11 above the loading surface of the additional paper output tray 80, and a lower conveying path 13 (first conveying path) for conveying the sheets via the sheet discharge outlet 131 of the MFP 130 toward the sheet receiving port (not shown) of the post-processing device 70.

[0043] The conveying path switching claw 14 is controlled by the control unit 50 and changes its inclination by a driving unit such as a solenoid to switch the conveying path.

[0044] (2) Additional output tray FIG. 2 is a perspective view for explaining the positional relationship between the post-processing device 70 and the additional paper discharge tray 80. As shown in FIG.

[0045] As shown in the same figure, the additional paper output tray 80 is arranged above the main body of the post-processing device 70, and a slit hole 81 that penetrates the additional paper output tray 80 is formed in approximately the center of the additional paper output tray 80 in the width direction (direction perpendicular to the paper output direction), and through this slit hole 81, the protruding portion 911a of the detection lever 911 of the sheet detection sensor 90 (Figure 4) protrudes above the sheet loading surface and is exposed.

[0046] A cover member 83 is formed integrally with the additional discharge tray 80 at the rear side of the additional discharge tray 80, and serves as an exterior of the side plate portion 72 by covering the upper part of the side plate portion 72 standing upward at the rear side of the post-processing device 70.

[0047] In addition, the additional output tray 80 is fixed within the internal space DSP of the MFP 130 via this cover member 83, while the side panel portion 72 of the post-processing device 70 is slidable within the cover member 83 and can be pulled out in the X direction together with the post-processing device 70 main body.

[0048] In reality, numerous ribs are formed parallel to the discharge direction on the top surface of the additional discharge tray 80 to reduce contact resistance with the sheet, but these have been omitted from the illustration to simplify the drawing and make the features easier to understand.

[0049] (3) Addition of extended post-processing equipment The image forming system 100 according to this embodiment is configured so that an extended post-processing device 75 capable of performing post-processing that the post-processing device 70 cannot perform (for example, punching) can be additionally installed.

[0050] FIG. 3 is a front view showing the image forming system 100 after the extended post-processing device 75 has been installed.

[0051] As shown in the figure, the post-processing device 70 is moved by a distance L in the X direction, and an extended post-processing device 75 is installed between the post-processing device 70 and the sheet discharge port 131 of the MFP 130. In this embodiment, a control unit is also built into the extended post-processing device 75, and performs post-processing instructed by the user under the control of the control unit 50 of the MFP 130 connected via a connector or the like.

[0052] Incidentally, in this embodiment as well, the actuator part of the sheet detection sensor is pivotally supported on the additional discharge tray 80 side so that it can swing, and the photoelectric sensor is positioned on the post-processing device 70 side. However, when the sheet detection sensor is configured as in the conventional configuration shown in Figure 7, if the post-processing device 70 is moved by a distance L in the X direction to mount the extended post-processing device 75 (second position), the photoelectric sensor 1014 also moves accordingly. However, since the actuator 1010 attached to the additional discharge tray is fixed in position, the photoelectric sensor 1014 can no longer detect the light shielding plate 1013 that is the detection target, and sheet detection becomes impossible.

[0053] Therefore, as mentioned above, providing a separate photoelectric sensor or replacing the original photoelectric sensor in a new position after the movement increases costs and increases the number of work steps unnecessarily.

[0054] Therefore, the inventors of the present application have created a sheet detection sensor (sheet detection means) that is low-cost and has a simple configuration, yet can easily detect sheets whether the post-processing device 70 is in the position shown in Figure 1 (first position) or the position shown in Figure 3 (second position).

[0055] (4) Sheet detection sensor configuration FIG. 4 is a perspective view showing the configuration of the sheet detection sensor 90 according to the present embodiment when the post-processing device 70 is in the first position.

[0056] As shown in the figure, the sheet detection sensor 90 is made up of a first actuator 91, a second actuator 92, and a photoelectric sensor 93.

[0057] The first actuator 91 includes a rod member 912 that is pivotally supported on a bearing member (not shown) provided on the back surface of the additional output tray 80, a detection lever 911 attached to the front end of the rod member 912 (corresponding to the position of the slit hole 81 in Figure 2), and a swing lever 913 attached to the other end of the rod member 912.

[0058] The second actuator 92 also includes a first blade member 921 (first swingable member) and a second blade member 923 (second swingable member) attached to both ends of a shaft body 922 that is swingably supported on the side plate portion 72 (Figure 5) of the post-processing device 70, at positions shifted (moved) by a distance L in the axial direction, and a light-blocking member 924 attached to a position approximately midway between the first blade member 921 and the second blade member 923.

[0059] The width of the first blade member 921 and the second blade member 923 in the direction parallel to the shaft 922 need only be large enough to abut the tip of the swing lever 913, which swings from the position before sheet detection by the detection lever 911 to the position after sheet detection (a state in which the protrusion 911a is buried in the slit hole 81 due to the weight of the sheets loaded in the additional paper output tray 80) when the post-processing device 70 is in the first position or the second position, and as long as this condition is met, the first blade member 921 and the second blade member 923 do not necessarily have to be in a position shifted exactly by the distance L.

[0060] The photoelectric sensor 93 includes a light emitting section 931 incorporating a light emitting element such as an LED (light emitting diode), and a light receiving section 932 incorporating a light detecting element such as a PD (photodiode).

[0061] The photoelectric sensor 93 is attached to the side plate portion 72 of the post-treatment device 70 via a mounting bracket 933 .

[0062] The size, shape, and mounting angle of the swinging members of the sheet detection sensor 90, including the detection lever 911, are determined so that the rotational torque due to the weight of each swinging part is balanced in order to maintain the state shown in Figure 2 when there are no sheets on the additional discharge tray 80.

[0063] In this state, the protrusion 911a of the detection lever 911 protrudes upward from the slit hole 81 (Figure 2) of the additional paper output tray 80, and when even one sheet is discharged onto the additional paper output tray 80, the protrusion 911a is pressed, causing the detection lever 911 to swing in the direction A in Figure 4, the rod member 912 to rotate in the direction B, and the swing lever 913 to swing in the direction C.

[0064] When the post-processing device 70 is in the first position, the tip of the swing lever 913 abuts against the underside of the first blade member 921 of the second actuator 92, and the swinging action of the swing lever 913 causes the shaft 922 to rotate in the direction D, and the light-shielding member 924 to swing in the direction E accordingly.

[0065] As a result, the light blocking member 924 is no longer present in the gap between the light emitting portion 931 and the light receiving portion 932 of the photoelectric sensor 93, and a signal indicating that the presence of a sheet has been detected is transmitted to the control unit 50.

[0066] FIG. 5 is a perspective view showing the state when the second actuator 92 and the photoelectric sensor 93 of the sheet detection sensor 90 are attached to the side plate portion 72 of the post-processing device 70.

[0067] As shown in the same figure, the shaft 922 of the second actuator 92 is pivotally supported at both ends by bearing portions 721, 722 provided on the side plate portion 72, and the first blade members 921, 923 protrude toward the front side (the additional paper output tray 80 side in Figure 2) through openings 723, 724 in the side plate portion 72, respectively, and are each able to abut against the swing lever 913 of the first actuator 91 in accordance with the movement of the post-processing device 70.

[0068] The photoelectric sensor 93 is also attached to the light blocking member 924 on the rear surface of the side plate 72 at a detectable position via a mounting bracket 933 .

[0069] 6(a) shows the positional relationship between the first actuator 91 and the second actuator 92 when the post-processing device 70 is in the first position. When the first actuator 91 physically detects the presence of a sheet and swings the swing lever 913, the first actuator 91 abuts against the first blade member 921, causing the light-blocking member 924 to swing in a direction that releases the light-blocking state of the photoelectric sensor 93, thereby enabling the sheet to be detected.

[0070] As shown in Figure 6(b), when the post-processing device 70 is moved to the second position to install the extended post-processing device 75, the swing lever 913 abuts against the second blade member 923, causing the light-shielding member 924 to swing. Therefore, regardless of whether the post-processing device 70 is in the first or second position, the single photoelectric sensor 93 can reliably detect sheets on the additional discharge tray 80 without having to change its position.

[0071] This reduces the cost of installing a photoelectric sensor for detecting sheets in a movable post-processing device, and eliminates the need to change the position of the photoelectric sensor in the post-processing device.

[0072] When the sheet detection sensor 90 detects that a sheet remains on the additional paper output tray 80, the control unit 50 displays a message to that effect on the display unit 61 of the operation panel 60, emits a sound, or turns on a dedicated lamp to urge the user to collect the sheet, thereby reducing the number of sheets left behind.

[0073] <Modification> The image forming system according to the embodiment of the present disclosure has been described above, but the contents of the present invention are not limited to the above embodiment, and the following modifications can be implemented.

[0074] (1) In the above embodiment, a transmissive photoelectric sensor (photointerrupter) is used as the photoelectric sensor 93 of the sheet detection sensor 90, but a reflective photoelectric sensor or other known non-contact sensors may also be used.

[0075] Furthermore, for example, by making the arm length of the detection lever 911 longer, the rocking torque applied to the second actuator 92 when the first actuator 91 detects the sheet can be increased, so in some cases, it is also possible to use a contact-type switching element such as a limit switch, and any sensor that detects the rocking movement of the object to be detected (in this embodiment, the second actuator 92) and generates an electrical signal will suffice.

[0076] (2) In the above embodiment, the second actuator 92 of the sheet detection sensor 90 is provided with two first and second blade members 921 and 923 so that sheets on the additional paper output tray 80 can be detected when the post-processing device 70 is in either of the first or second positions. However, if the number of extended post-processing devices is further increased, or if there is only one extended post-processing device but the width in the paper output direction varies depending on the type, it may be necessary to move the post-processing device 70 to three or more different stop positions depending on the installation conditions.

[0077] Even in this case, the shaft body 922 of the second actuator 92 may be lengthened, and blade members (moved members) may be provided at positions that come into contact with the swing lever 913 at each of the plurality of stop positions.

[0078] (3) In the above embodiment, stapling is given as an example of post-processing performed by the post-processing device 70, and punching is given as an example of post-processing performed by the extended post-processing device 75, but each may be configured to perform other post-processing.

[0079] For example, it may be a shift sorter that sorts sheets by shifting them in a direction perpendicular to the conveying direction each time they are output, a job separator that has multiple output destinations without performing any processing, or a device that performs folding or cutting processing, or a combination of these.

[0080] (4) In the above embodiment, an MFP is used as an example of the image forming apparatus in the image forming system, but the present invention is not limited to this and can also be applied to image forming apparatuses such as facsimiles.

[0081] The image forming apparatus may be an image forming apparatus that forms not only color images but also monochrome images, and is not limited to an electrophotographic image forming apparatus but may also be, for example, an inkjet linter.

[0082] Furthermore, the present invention is not necessarily limited to an internal discharge type, but can also be applied to an image forming system in which a post-processing device is installed in a discharge space that is open at the top. Even in this case, depending on the user's situation (for example, if the user leaves the MFP to do something else immediately after instructing the MFP to execute a copy job), the user may forget to remove a sheet from the additional discharge tray on the post-processing device.

[0083] <Supplementary information> While the image forming system according to the present disclosure has been described above based on the embodiments and modifications, the present invention is not limited to the above-described embodiments and modifications. The present invention also includes forms obtained by applying various modifications to the above-described embodiments and modifications that would occur to a person skilled in the art, and forms realized by arbitrarily combining the components and functions of the embodiments and modifications within the scope of the present invention. [Industrial Applicability]

[0084] The present disclosure can be widely applied to detection of sheets on a paper discharge tray in an image forming system in which a post-processing device is movably mounted in the paper discharge space of the image forming apparatus. [Explanation of symbols]

[0085] 10 Image forming unit 11 Conveyor path 12 Upper transport path (second transport path) 13 Lower transport path (first transport path) 14 Conveyor path switching claw 50 control section 60 Operation Panel 61 Display section 70 Aftertreatment device 71 Post-processing output tray 72 Side plate part 75 Extended post-processing device 80 Additional output tray 81 Slit hole 83 Cover member 90 Sheet detection sensor 91 First Actuator 92 Second Actuator 93 Photoelectric Sensor 100 Image forming system 110 Scanner 120 printers 130 MFP 131 Sheet outlet 911 detection lever 912 Rod member 913 Swing lever 921 First blade member (first swingable member) 922 Shaft 923 Second blade member (second swingable member) 924 Light blocking material

Claims

1. An image forming system in which a post-processing device is mounted in a paper discharge space of an image forming device so as to be movable along a paper discharge direction, a sheet ejection tray for stacking sheets ejected from the image forming apparatus above the post-processing apparatus is fixed to the image forming apparatus; a detecting means for detecting the presence or absence of a sheet on the paper discharge tray, the detecting means comprising a first actuator including a swing lever that swings in response to detecting a sheet; a second actuator including first and second swingable members that come into contact with the swing lever when the post-processing device is located at a first position or a second position in the paper discharge direction, and a sensor that detects the swinging operation of the second actuator; The first actuator is disposed in the paper discharge tray, and the second actuator and the sensor are disposed in the post-processing device. An image forming system comprising:

2. The image forming apparatus has an original reading unit disposed above an image forming unit, and the paper discharge space is provided between the image forming unit and the original reading unit.

2. The image forming system according to claim 1.

3. The image forming apparatus includes a first transport path for discharging an image-formed sheet toward the post-processing device, a second transport path for discharging the sheet toward the paper discharge tray without passing through the post-processing device, and a switching unit for switching between the first and second transport paths.

3. The image forming system according to claim 1, further comprising:

4. The post-processing device is moved to a second position downstream in a sheet discharge direction from the first position, and another post-processing device can be installed between the sheet discharge outlet of the first transport path of the image forming apparatus and the post-processing device.

4. The image forming system according to claim 3.

5. the first and second swingable members of the second actuator are spaced apart in a direction parallel to the direction of movement of the post-processing device, The distance is a distance at which the first swingable member abuts against the swing lever when the post-processing device is in the first position, and a distance at which the second swingable member abuts against the swing lever when the post-processing device is in the second position.

5. The image forming system according to claim 1, wherein the image forming apparatus is a printer.

Images