Discharge device and image forming apparatus

Abstract

The visibility of the discharged sheets is poor. [Solution] The discharge device includes a first tray for receiving sheets discharged by a first discharge unit, a second tray provided above the first tray for receiving sheets discharged by a second discharge unit, and a rear end restrictor that can move in the sheet discharge direction while in contact with the rear end of the sheets loaded on the first tray in the sheet discharge direction.

Description

Technical Field

[0006] ,

[0007] , ,

[0001] The present invention relates to a discharging device for discharging sheets, and an image forming apparatus such as a copying machine or a printer including the same.

Background Art

[0002] Conventionally, for example, a configuration has been proposed in which a multi-stage paper discharge unit is arranged above an image reading device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the prior art, the interval between the paper discharge trays is only the height required for paper discharge, and the visibility of the sheets on the paper discharge trays is poor.

[0005] In particular, when small-sized paper is discharged onto a paper discharge tray below a paper discharge tray on which large-sized paper is stacked, the visibility of the small-sized paper is poor.

Means for Solving the Problems

[0006] The discharging device of the present invention includes: a first discharging unit for discharging sheets; a first tray for receiving the sheets discharged by the first discharging unit; a second discharging unit for discharging sheets; a second tray provided above the first tray for receiving the sheets discharged by the second discharging unit; and a rear end regulation that can move in the sheet discharging direction and contacts the rear end of the sheets stacked on the first tray in the sheet discharging direction.

Effects of the Invention

[0007] According to the present invention, the visibility of the discharged sheets can be improved. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic cross-sectional view of the image forming apparatus according to the first embodiment. [Figure 2] A schematic vertical cross-sectional view showing the open state of the second housing 33 in Figure 1. [Figure 3] Enlarged view of the mounting section of the receiving tray 35 of the multi-stage paper output unit 3. [Figure 4] A diagram showing the drive unit of the rear end restrictor 50 of the multi-stage paper output section 3. [Figure 5] A block diagram representing the control unit. [Figure 6] A flowchart showing the control for moving the rear end restrictor to the extraction position. [Figure 7] A flowchart showing the control for moving the rear end restrictor to the paper output position. [Figure 8] An enlarged view of the mounting portion of the receiving tray 35 of the multi-stage paper output unit 3 in the second embodiment. [Figure 9] A flowchart illustrating the control for moving the rear end restrictor to the removal position in the second embodiment. [Modes for carrying out the invention]

[0009] A first embodiment of the present invention will be described below with reference to the drawings.

[0010] [Configuration of the image forming apparatus according to the first embodiment] The overall configuration of the image forming apparatus will be outlined with reference to Figure 1. Figure 1 is a schematic vertical cross-sectional view of one embodiment of the image forming apparatus according to the first embodiment. The image forming apparatus comprises a main body 1 including an image forming unit 2, a multi-stage paper output unit 3, and an image reading unit 4.

[0011] [Configuration of the main unit 1 of the device] The configuration of the main body 1 of the first embodiment will be described with reference to Figure 1.

[0012] The main body of the apparatus 1 has a paper feeding means 14 at the bottom for transporting the sheet S stored in the paper feed cassette 100 into the image forming unit 2. Downstream of the paper feeding means 14 is a resist roller unit 16 for transporting the resist on the sheet S. Above the paper feeding means 14 are four process cartridges 6Y, 6M, 6C, and 6Bk. The process cartridges 6Y, 6M, 6C, and 6Bk have photosensitive drums 9Y, 9M, 9C, and 9Bk. Above the process cartridges 6Y, 6M, 6C, and 6Bk, an intermediate transfer unit 70 is positioned opposite the process cartridges 6Y, 6M, 6C, and 6Bk. The intermediate transfer unit 70 is equipped with an intermediate transfer belt 8, and inside the intermediate transfer belt 8 are primary transfer rollers 5Y, 5M, 5C, and 5Bk, a secondary transfer opposing roller 10, and a tension roller 11. On the right side of the intermediate transfer unit 70, a secondary transfer roller 12 is provided so as to face the secondary transfer opposing roller 10.

[0013] A fixing unit 20 is located downstream of the secondary transfer section. Downstream of the fixing unit 20 are a pair of paper discharge rollers 22 and a flapper 21, which is a branching means. Downstream of the pair of paper discharge rollers 22 is a paper discharge tray 90 located inside the cylinder. An outlet 23 is provided above the flapper 21. Inside the main body 2 of the device, a paper discharge path R10 is formed through which paper is transported from the fixing unit 20 to the pair of paper discharge rollers 22, and an outlet path R20 is formed that branches off from the paper discharge path R10 and leads to the outlet 23. The flapper 21 is located at the branching point of the paper discharge path R10 and the outlet path R20. The flapper 21 is pivotable around a flapper axis 21a that extends in the left-right direction and is configured to selectively transport paper to either the paper discharge path R10 or the outlet path R20. When the paper discharge path R10 is selected, the paper is discharged to the paper discharge tray 90. In this embodiment, the outlet path R20 extends linearly along the vertical direction, the Z direction in Figure 1.

[0014] [Configuration of the multi-stage paper output unit 3] Referring to FIGS. 1 and 2, the configuration of the multi-stage paper discharge unit 3 according to the first embodiment will be described. The multi-stage paper discharge unit 3 is a device that receives the sheet on which an image is formed by the image forming unit 2 and stacks the sheets.

[0015] As shown in FIGS. 1 and 2, the multi-stage paper discharge unit 3 has a first housing 31, a pair of conveying rollers 32, a second housing 33, and four receiving trays (paper discharge trays) 35.

[0016] The multi-stage paper discharge unit 3 as a discharge device is detachable from the upper surface of the apparatus main body 1, and the first housing 31 houses the pair of conveying rollers 32 inside. On the lower surface of the first housing 31, a receiving port 34 corresponding to the discharge port 23 is formed. The discharge port 23 and the receiving port 34 are arranged in the vertical direction (Z direction in FIG. 1) and coincide with each other when viewed from the vertical direction. Inside the first housing 31, an optional paper discharge path R30 is formed through which the paper is conveyed from the receiving port 34 toward each receiving tray 35 by the pair of conveying rollers 32.

[0017] The optional paper discharge path R30 includes a plurality of paths. That is, the optional paper discharge path R30 includes a path toward the uppermost receiving tray among the four receiving trays 35. The optional paper discharge path R30 further includes paths that branch at three branch positions provided in the optional paper discharge path R30 and head toward each of the three lower receiving trays 35 among the four receiving trays 35. Switching members 36 are provided at each of the three branch positions. Each switching member 36 is swingable about a switching shaft 36a extending in the left-right direction. Each switching member 36 is movable so as to selectively take a position for conveying the paper to the receiving tray � and a position for conveying the paper upward.

[0018] One of the pair of conveying rollers 32 is provided on the first housing 31. The other of the pair of conveying rollers 32 is provided on the second housing 33. When the second housing 33 is closed, the pair of conveying rollers 32 is in a pressed state. The paper is conveyed by frictional force when the paper passes through the pressing point of the pair of conveying rollers 32 in the pressed state.

[0019] Of the multiple transport roller pairs 32, the lowest transport roller pair 32, which acts as the first discharge unit, transports the sheet in the sheet discharge direction, thereby discharging the sheet to the lowest receiving tray 35, which acts as the first tray. Of the multiple transport roller pairs 32, the second from the bottom transport roller pair 32, which acts as the second discharge unit, discharges the sheet to the second receiving tray 35, which acts as the second tray. Of the multiple transport roller pairs 32, the third from the bottom transport roller pair 32, which acts as the third discharge unit, discharges the sheet to the third receiving tray 35, which acts as the third receiving tray 35. Of the multiple transport roller pairs 32, the uppermost transport roller pair 32, which acts as the fourth discharge unit, discharges the sheet to the uppermost receiving tray 35.

[0020] As shown in Figure 2, the second housing 33 can be opened so that the optional paper output path R30 is released.

[0021] [Configuration of Image Reading Device 4] The image reading device 4 consists of a document holder 42 and an image reading unit 41. The document holder 42 is mounted on the image reading unit 41 so as to be pivotable by a pivoting unit 45.

[0022] The image reading unit 41 is equipped with a flat document tray 43, and can read the image of a document placed on the document tray 43 using an internally located reading sensor reading means (not shown). The user can rotate the document holder 42 to place the document directly on the document tray 43, thereby allowing the image reading device 4 to read the document.

[0023] The first embodiment of this model will be described in detail with reference to Figures 3 to 7.

[0024] Figure 3 is an enlarged view of the mounting portion of the receiving tray 35 of the multi-stage paper output unit 3, and Figure 4 is an extracted view of the drive unit of the rear end restrictor 50 of the multi-stage paper output unit 3. Figure 5 is a block diagram representing the control unit. Figure 6 is a flowchart showing the control for moving the rear end restrictor 50 to the ejection position, and Figure 7 is a flowchart showing the control for moving the rear end restrictor 50 to the paper output position.

[0025] In the figure, 50 is a rear end restrictor located upstream of the receiving tray 35. 51a and 51b are planetary gears for switching the direction of drive of the rear end restrictor 50. 51c is an input gear for transmitting drive from the main drive to the planetary gear. The main drive refers to the drive system including the motor located in the main body 1 of the device. In other words, the input gear 51c rotates by receiving the driving force from the motor located in the main body 1 of the device. 52 is a switching solenoid for switching the forward and reverse rotation of the drive by the planetary gear, and 53 is an electromagnetic clutch for transmitting drive to each rear end restrictor. The rear end restrictor 50 has a detection sensor 54 for detecting the presence or absence of a loaded sheet S and is fixed to a transmission belt 55 for transmitting drive.

[0026] When the image forming unit 2 is driven, the drive from the main unit is transmitted from the input drive gear 51c through the planetary gear 51a, driving the rear end restrictor 50 in the direction of transporting it downstream. While the switching solenoid 52 is ON, the planetary gear 51b drives the rear end restrictor 50 in the direction of transporting it upstream. The drive to the transmission belt 55 fixed to the rear end restrictor 50 is transmitted only while the electromagnetic clutch 53 is ON.

[0027] The rear end restrictor 50 is fixed to the transmission belt 55 at the tray end and moves in either the ejection position or the paper ejection position when the electromagnetic clutch 53 is turned ON. In this way, the rear end restrictor 50 is configured to move individually through the action of multiple electromagnetic clutches 53.

[0028] In Figure 5, 60 is the CPU that controls the operation of the image forming apparatus 1. 61 is the memory that holds the information used by the CPU.

[0029] The operation of transferring sheets on the receiving tray downstream in the sheet discharge direction, controlled by the CPU 60, will be explained with reference to Figure 6. When the CPU 60 detects, using a detection sensor (not shown) installed in the paper discharge section, that all the sheets S that have been instructed to be output have been transported to the receiving tray 35, it starts controlling the rear end restriction (S1). When the CPU 60 detects that small-sized paper has been output to the receiving tray 35 (S2), it calculates the amount of movement of the rear end restriction 50 from the difference between the maximum output size and the size of the paper output to the receiving tray 35. The CPU 60 sets the movement time (S3). The CPU 60 stores the set time in memory 61 for each receiving tray 35 that has been output with small-sized paper. If the output small-sized paper is a standard size, it is also possible to store the set time in memory 61 in advance.

[0030] The CPU 60 turns on the electromagnetic clutch 53 of the receiving tray 35 that has output a small size sheet (S4). The CPU 60 keeps the electromagnetic clutch ON for a set time (S5). When the set time is up, the CPU 60 turns off the electromagnetic clutch (S6), thereby ending the control of the rear end restrictor 50 to the removal position (S7). The sheet moves downstream in the discharge direction as its rear end is pushed by the rear end restrictor 50. In other words, the leading edge of the sheet S loaded in the receiving tray 35 moves towards the leading edge of the output tray, completing the movement of the sheet S to the removal position. As a result, even when a small size sheet is output to the receiving tray 35, the sheet S in the receiving tray 35 can be seen. The set time is set according to the size of the sheet being output (length in the transport direction). Therefore, the sheet can be moved so that the leading edge of the sheet S loaded in the receiving tray 35 is in the desired position, regardless of the sheet size. Thus, the visibility of the sheet is increased and the sheet can be easily removed, regardless of the sheet size.

[0031] Next, the operation of returning the rear end restrictor 50, which has moved to the ejection position, to the paper output position will be explained using Figure 7.

[0032] The output signal copy button is pressed on the image forming apparatus 1. When the CPU 60 detects that a print / fax output signal has been received, the image forming unit 2 starts output operation (S11) and the drive unit starts operation. In the receiving tray 35, where the rear end restrictor 50 has been moved to the ejection position, the detection sensor 54 of the rear end restrictor 50 detects that there is no paper. Alternatively, output of sheet S is specified to the receiving tray 35 (S12). Then, the CPU 60 reads from the memory 61 and sets the same time as the set time set for the movement of the rear end restrictor 50 of each receiving tray 35 to the ejection position (S13). The CPU 60 turns on the switching solenoid 52 that switches the drive direction of the rear end restrictor 50 (S14) and turns on the electromagnetic clutch 53 (S15). When the ON time of the electromagnetic clutch 53 reaches the set time (S16), the CPU 60 turns off the electromagnetic clutch 53 (S17). Subsequently, the CPU 60 turns OFF the switching solenoid 52 (S18), completing the movement of the rear end restrictor 50 to the paper output position (S19). When the rear end restrictor 50 is in the paper output position, the sheet is ejected beyond the rear end restrictor 50, and the rear end of the sheet received in the receiving tray 35 comes into contact with the rear end restrictor 50.

[0033] As described above, the rear end restriction 50 can be set to any position according to the output sheet size (length in the discharge direction). Therefore, visibility is good even when outputting irregularly shaped sheets.

[0034] Furthermore, the rear end restrictors 50 provided for each receiving tray 35 can be moved independently. Therefore, the amount of movement of the rear end restrictors 50 can be arbitrarily set for each receiving tray 35, and there is no restriction on the output size relative to the receiving tray 35.

[0035] In this embodiment, a configuration in which the image reading unit 4 is positioned above the image forming unit 2 and the multi-stage paper output unit 3 is positioned above the image reading unit 4 has been described as an example. However, the same effect can be obtained even in the case of an image forming apparatus that does not have an image reading unit 4.

[0036] (Second embodiment) Next, a second embodiment of the present invention will be described using Figures 8 and 9.

[0037] The following description of the second embodiment will only explain the differences from the first embodiment.

[0038] Figure 8 is an enlarged view of the mounting portion of the receiving tray 35 of the multi-stage paper output unit 3 in the second embodiment, and Figure 9 is a flowchart showing the control for moving the rear end restrictor 50 in the second embodiment to the removal position.

[0039] In Figure 8, 35a is a detection sensor provided on the receiving tray 35.

[0040] The operation of the rear end restrictor 50 will be explained below based on Figure 9. When sheet transport to the receiving tray 35 is completed, control of the rear end restrictor 50 is started (S21). When the CPU 60 detects that a small-sized sheet has been output to the receiving tray 35 (S22), it turns on the electromagnetic clutch of the receiving tray 35 that output the small-sized sheet (S23). The CPU 60 then starts counting the time the electromagnetic clutch is ON (S24). When the detection sensor 35a detects the leading edge of the sheet or the rear end restrictor 50 (S25), the CPU 60 turns off the electromagnetic clutch (S26).

[0041] The CPU 60 finishes counting the set time (S27). The CPU 60 finishes controlling the movement of the rear end restrictor 50 to the ejection position (S28). At this point, the count value is retrieved for each receiving tray 35 that has printed small-sized paper and stored in the memory 61 as the movement set time.

[0042] As a result of the above operation, the sheet S loaded on the receiving tray 35 is pushed by the rear end restrictor 50 and moves in the discharge direction, completing the movement of the sheet S to the removal position. Even when a small size is output to the receiving tray 35, the sheet S in the receiving tray 35 can be seen. Similar to the first embodiment, the leading edge of the sheet stops at the desired position regardless of size (regardless of whether it is a longer or shorter small sheet), so the sheet is highly visible and easy to remove.

[0043] The operation of returning the rear end restrictor 50, which has moved to the ejection position, to the paper output position is the same as in the first embodiment, although there is a difference between the calculated ejection setting time and the counted setting time, so the explanation is omitted here.

[0044] Although an example was given in which each of the multiple receiving trays 35 is provided with a movable rear end restraint, the configuration is not limited to this. Rear end restraints should be provided only on the necessary receiving trays 35. For example, the uppermost receiving tray 35 may be configured without a movable rear end restraint.

[0045] In the embodiments described above, an electrophotographic image forming unit was used as an example. However, an electrostatic recording or inkjet image forming unit may also be used.

[0046] In the above embodiment, a configuration in which the rear end restrictor is moved by a motor was illustrated. However, a configuration in which the user moves the rear end restrictor manually is also possible. In this case, a lever integrated with the rear end restrictor is provided as an operating part for the user.

[0047] The effects of the above embodiment are described below.

[0048] This allows us to provide a space-saving product with multi-tier trays positioned above the device and arranged at the height pitch required for paper output.

[0049] The rear end restraints of the multiple receiving trays move the outputted sheets downstream in the sheet discharge direction. Therefore, the sheets are easily visible regardless of which receiving tray they are output to. For example, suppose a small sheet is loaded onto the bottom receiving tray (the first tray), and a large sheet is output to the second receiving tray (the second tray from the bottom). Even in this case, the small sheet on the bottom receiving tray is still easily visible.

[0050] The rear end restraint can be moved to any position for each receiving tray. There is no need to restrict the size of the sheets ejected from the receiving tray, and it can be freely set by the height at which the device is placed.

[0051] The rear end restraint can be moved to any position for each receiving tray to match the size of the sheet ejected onto the receiving tray. Therefore, visibility can be ensured without limiting the size of the sheet ejected onto the receiving tray.

[0052] As in the second embodiment, by providing a sheet detection means downstream of the output tray, the leading edge of the sheet on the moving receiving tray can be detected and the trailing edge restriction can be stopped.

[0053] If the size is larger than the minimum size at which the rear-end restriction can be output, the system can detect the rear-end restriction and stop its movement. [Explanation of Symbols]

[0054] 35 Receiving tray 35a Detection Sensor 50 Rear end regulation

Claims

1. A first discharge section for discharging the sheet, A first tray for receiving the sheets discharged by the first discharge unit, A second discharge section for discharging the sheet, A second tray is provided above the first tray to receive the sheets discharged by the second discharge unit, A discharge device characterized by having a rear end restrictor that can move in the sheet discharge direction while in contact with the rear end of the sheet loaded on the first tray in the sheet discharge direction.

2. The second tray is equipped with a second rear end restraint that can move in the sheet discharge direction while in contact with the rear end of the sheet loaded on the second tray in the sheet discharge direction. The discharge device according to claim 1, characterized in that the rear end restrictor and the second rear end restrictor are configured to be movable independently.

3. The discharge device according to claim 1, characterized in that it comprises a drive unit for moving the first rear end restrictor.

4. The discharge device according to claim 1, further characterized in that a detection sensor is provided in either the first rear end restrictor or the first receiving tray for detecting the presence or absence of the sheet S.

5. The discharge device according to claim 1, characterized in that the rear end restrictor is moved by a motor.

6. An image forming unit that forms an image on a sheet, An image forming apparatus characterized by having a discharge device according to claim 1 for discharging a sheet on which an image has been formed by the image forming unit.

Images