JP7516003B2 - Sheet sorting device and image forming device - Google Patents

Description

The present invention relates to a sheet sorting device and an image forming device having multiple discharge trays, including a removable discharge tray.

Some conventional image forming devices are equipped with a sheet sorting device that has multiple discharge trays. This device sorts sheets by discharging sheets to a separate discharge tray for each user, for example.

Patent Document 1 describes a sheet sorting device in which multiple discharge trays can be removed from the device body. For example, by removing a first tray from the multiple discharge trays, the sheet stacking space of the second tray located below the first tray can be expanded, and the maximum number of sheets that can be stacked on the second tray can be increased.

JP 2000-44105 A

However, Patent Document 1 does not describe how to control what happens when the first tray is removed when the second tray is fully loaded.

The object of the present invention is to improve usability when the discharge tray located above the discharge tray that has been detected as fully loaded is removed from the device body.

In order to achieve the above object, the sheet sorting device of the present invention has a first tray that is removable from a device body, a second tray that is arranged below the first tray in a vertical direction, a tray detection means that detects that the first tray has been removed from the device body, a load detection means that detects that an amount of sheets loaded on the second tray has reached a predetermined amount, and a control means that, when the load detection means detects that the amount of sheets has reached the predetermined amount, controls so that sheets are not conveyed to the second tray, and a first discharge outlet is formed at a position corresponding to the first tray, and a second discharge outlet is formed at a position corresponding to the second tray. In a sheet sorting device having a sheet sorting function, when the load amount detection means detects that the sheet amount has reached the predetermined amount, the control means interrupts image formation on the sheet and switches to a prohibited state in which the sheet is prohibited from being transported from the second discharge outlet to the second tray, and when the tray detection means detects that the first tray has been removed from the device main body in the prohibited state, the control means resumes image formation on the sheet , performs image formation on the sheet that was prohibited from being transported from the second discharge outlet to the second tray, and switches to an permitted state in which the sheet is permitted to be transported from the first discharge outlet to the second tray.

According to the present invention, it is possible to improve usability when the discharge tray located above the discharge tray that has been detected as being fully loaded is removed from the device body.

1 is a diagram illustrating a configuration of an image forming apparatus and a sheet sorting apparatus according to a first embodiment. 2 is a block diagram showing a control unit and a functional configuration of the image forming apparatus according to the first embodiment. FIG. FIG. 4 is a detailed diagram of a sorting device control unit in the first embodiment. 11A and 11B are diagrams illustrating when a full stack is detected and when a discharge tray is removed in the first embodiment. 5 is a flowchart showing a process for detecting a full load in the first embodiment. 13 is a diagram showing an example of setting the state of the discharge tray and the discharge port. 5 is a flowchart showing a process for releasing a full load in the first embodiment. FIG. 11 is a diagram illustrating the configurations of an image forming apparatus and a sheet sorting apparatus according to a second embodiment. FIG. 11 is a block diagram showing a control unit and a functional configuration of an image forming apparatus according to a second embodiment. FIG. 11 is a detailed diagram of a sorting device control unit in the second embodiment. 13 is a flowchart showing a process for detecting a full load in the second embodiment. 13 is a flowchart showing a process for releasing a full load in the second embodiment.

Example 1
In the first embodiment, a configuration employing a flag-type full load detection sensor will be described.

(Configuration diagram of an image forming apparatus)
1 is a diagram showing a schematic structure of an image forming apparatus according to a first embodiment of the present invention. In this embodiment, a laser beam printer 100 (hereinafter, referred to as printer 100) is shown as an example of the image forming apparatus.

As shown in FIG. 1, the printer 100 is provided with an image forming unit 101, a feeding unit 102 that feeds a sheet S (recording material) such as paper to the image forming unit 101, a fixing unit 103 that fixes the image formed on the sheet S by the image forming unit 101, and a discharge unit 104. In addition, a sheet sorting device 200 that receives the sheet S on which the image has been formed from the printer 100 and sorts the sheet S is provided above the printer 100.

The image forming unit 101 has a photosensitive drum 111 that rotates counterclockwise in FIG. 1, a charging roller 112 that charges the surface of the photosensitive drum 111, and an exposure device 113 that irradiates the charged photosensitive drum 111 with light to form an electrostatic latent image on the photosensitive drum 111. The image forming unit 101 also has a developing device 114 that places toner on the electrostatic latent image to form a toner image on the photosensitive drum 111, and a transfer roller 115 that transfers the toner image to the conveyed sheet S. The image forming unit 101 forms a toner image on the sheet S through this image formation process. The fixing unit 103 also has a fixing roller 116 and a pressure roller 117 that forms a fixing nip with the fixing roller 116, and applies heat and pressure to the sheet S to fix the transferred toner image to the sheet S.

The feeding section 102 has a cassette 105 in which a plurality of sheets S to be used for image formation are stored in a stacked state, a feeding roller 106, a conveying guide 109, and a registration roller 110. The discharge section 104 has a switching member 120, a fixing discharge roller 118, a discharge guide 122, a discharge roller 123, a discharge tray 124, and a full-load detection flag 125. When the full-load detection flag 125 detects that the discharge tray 124 is full, the printer 100 does not discharge sheets S to the discharge tray 124 until the sheets S discharged to the discharge tray 124 are removed.

The switching member 120 is configured to be movable by an actuator (not shown) between a position indicated by a solid line where the sheet S after image formation is guided to the sheet sorting device 200 and a position indicated by a dashed line where the sheet S is guided to the discharge tray 124.

(Configuration diagram of sheet sorting device)
Next, the sheet sorting device 200 in this embodiment will be described with reference to FIG. 1. 201 is a conveying guide that guides the sheet S conveyed from the printer 100. The conveying guide 201 has a plurality of branching portions, and the branching portions are provided with discharge trays 210, 211, and 212, respectively. A pair of conveying rollers 202 and pairs of discharge rollers 601, 602, and 603 discharge the sheet S to one of the discharge trays 210, 211, and 212. The discharge trays 210, 211, and 212 are configured to be detachable from the device body 220 (also called a housing) of the sheet sorting device 200 as desired. Here, the switching member 402 and the switching member 403 are configured to be movable by an actuator (not shown) to the positions indicated by the solid lines and the positions indicated by the dashed lines in FIG. 1. For example, when discharging the sheet S to the discharge tray 210, the switching member 402 and the switching member 403 are moved to the positions indicated by the solid lines in FIG. 1, respectively. 1. When the sheet S is discharged onto the discharge tray 211, the switching member 402 is moved to the position indicated by the dashed line in FIG. 1, and the switching member 403 is moved to the position indicated by the solid line in FIG.

The tray detection sensors 407, 408, and 409 are sensors that detect whether the discharge trays 210, 211, and 212 have been removed from the device body 220. The tray detection sensors 407, 408, and 409 are, for example, photointerrupters that output an OFF signal when the discharge trays 210, 211, and 212 have been removed from the device body 220 and the light of the photointerrupter is not blocked in a light-transmitting state. Then, when the discharge trays 210, 211, and 212 are attached to the device body 220 and the light of the photointerrupter is blocked in a light-blocking state, the tray detection sensors output an ON signal.

The full-load detection flags 206, 207, and 208 are flags that move in contact with the surface of the sheet S discharged to the discharge trays 210, 211, and 212, respectively. The full-load detection sensors 404, 405, and 406 are sensors that detect the full-load state of the discharge trays 210, 211, and 212, respectively. The full-load detection sensors 404, 405, and 406 are, for example, photointerrupters, and output an OFF signal in a light-transmitting state in which light is not blocked by the full-load detection flags 206, 207, and 208. Then, as the sheet S is discharged to the discharge trays 210, 211, and 212, the full-load detection flags 206, 207, and 208 move, and output an ON signal in a light-blocking state in which light is blocked by the full-load detection flags 206, 207, and 208. Here, full-load means a state in which the amount of sheets S discharged to the discharge trays 210, 211, and 212 is greater than or equal to a predetermined amount. In this embodiment, the full-load detection flag 207 is removable from the device body 220 together with the discharge tray 210, and the full-load detection flag 208 is removable from the device body 220 together with the discharge tray 211. In other words, the full-load detection flag 207 is attached to the discharge tray 210, and the full-load detection flag 208 is attached to the discharge tray 211.

(Block diagram of control unit and functional configuration)
2 is a block diagram showing the functional configuration of the present embodiment. The printer 100 includes, as control units, a controller 301, a printer control unit 302 for controlling the printer 100, and a sorting device control unit 303 for controlling the sheet sorting device 200. The controller 301 communicates with an external device 300 such as a host computer to receive print data. The controller 301 also issues a print command to the printer control unit 302 by specifying print conditions created from the print data via a serial I/F. The printer control unit 302 controls each mechanism according to the print conditions received from the controller 301. Specifically, the printer control unit 302 controls a sheet transport mechanism 311 consisting of a feed unit 102 and a discharge unit 104 to feed and discharge the sheet S, and controls the image forming unit 101 and the fixing unit 103 to form and fix an image on the sheet S.

The controller 301 also specifies the sorting destination of the sheet S to the sorting device control unit 303 via the serial I/F. The sorting device control unit 303 controls each mechanism according to the sorting destination received from the controller 301. Specifically, it controls the sheet conveying mechanism 312 including the conveying roller pair 202, the discharge roller pairs 601, 602, 603, and the switching members 402, 403 to convey the image-formed sheet S. The sorting device control unit 303 also detects the presence or absence of the discharge trays 210, 211, 212 based on the detection results of the tray detection sensors 407, 408, 409. The sorting device control unit 303 also detects whether the discharge trays 210, 211, 212 are fully loaded based on the detection results of the full-load detection sensors 404, 405, 406.

(Details of the sorting device control section)
3 is a detailed diagram of the sorting device control unit 303 in this embodiment. The sorting device control unit 303 has a CPU 400, and communicates with the controller 301 via a serial communication means 427. The serial communication means 427 connects the CPU 400 and the controller 301 with a plurality of signal lines.

When the print data 428 is notified to the controller 301 through the external device 300, the controller 301 notifies the CPU 400 of the carry-in notice 423 signal and the discharge destination information 424 through the serial communication means 427. In addition, the CPU 400 notifies the controller 301 of the tray presence/absence state 425 signal through the serial communication means 427. In addition, when the CPU 400 notifies the controller 301 of the full load state 426 signal through the serial communication means 427, the controller 301 notifies the full load display 429 to the external device 300. Here, the notification of the full load display 429 means displaying a message or image on the screen of the external device 300 notifying that the tray to which the sheet S is discharged is full. Note that the target on which the message or image notifying full load is displayed is not limited to the external device 300, and the printer 100 or the sheet sorting device 200 may be provided with a liquid crystal panel (display unit) and the message or image may be displayed on the panel.

A motor driver 410 is connected to the output terminal of the CPU 400. The motor driver 410 drives the conveying motor 401. When the conveying motor 401 rotates, the conveying roller pair 202 and the discharge roller pairs 601, 602, and 603 rotate, and the sheet S is conveyed to the discharge trays 210, 211, and 212, respectively.

An actuator (not shown) that switches the position of the switching member 402 is connected to the output terminal of the CPU 400. When the actuator is ON, the switching member 402 is switched to the position shown by the dashed line in FIG. 1, and guides the sheet S in the direction of the discharge tray 211. When the actuator is OFF, the switching member 402 is switched to the position shown by the solid line in FIG. 1, and guides the sheet S in the direction of the discharge tray 210.

An actuator (not shown) that switches the position of the switching member 403 is connected to the output terminal of the CPU 400. When the actuator is ON, the switching member 403 is switched to the position shown by the dashed line in FIG. 1, and guides the sheet S in the direction of the discharge tray 212. When the actuator is OFF, the switching member 403 is switched to the position shown by the solid line in FIG. 1, and guides the sheet S in the direction of the discharge trays 210, 211.

The full load detection sensor 404 uses a pull-up 411 and inputs the sensor state (ON signal or OFF signal) to the CPU 400 via a buffer 412. The full load detection sensor 404 is a signal output unit that outputs a signal according to the position of the full load detection flag 206. The details of the full load detection sensors 405 and 406 are the same as those of the full load detection sensor 404, so a description thereof will be omitted. The full load detection sensors 405 and 406 correspond to the full load detection flags 207 and 208, respectively.

The tray detection sensor 407 uses a pull-up 417 and inputs the sensor state (ON signal or OFF signal) to the CPU 400 via a buffer 418. The details of the tray detection sensors 408 and 409 are the same as those of the tray detection sensor 407, so a description thereof will be omitted.

(Description of the operation of the sheet sorting device)
Next, the operation of the sheet sorting device 200 in this embodiment will be described with reference to Figures 4 to 7. Here, the case where the discharge tray 211 is fully loaded will be described.

Figure 5 is a flowchart that is executed when a sheet S is discharged to the discharge tray 211. The control based on the flowchart in Figure 5 is executed by the controller 301 shown in Figure 2 based on a program stored in a storage unit such as a ROM or RAM.

While the sheet S is being discharged to the discharge tray 211, the controller 301 checks whether the full-load detection sensor 405 is ON (S500). If the full-load detection sensor 405 is OFF, the controller 301 continues discharging the sheet S to the discharge tray 211. Then, as shown in FIG. 4A, when the discharge tray 211 is full and the full-load detection sensor 405 is ON, the controller 301 sets the state of the discharge tray 211 to "full" (S501). Also, in FIG. 4A, the device body 220 has discharge outlets 203, 204, and 205 formed at positions corresponding to the discharge trays 210, 211, and 212, respectively. The controller 301 also sets the state of the discharge outlet 204 corresponding to the discharge tray 211 to "full" (S502). FIG. 6A is a table summarizing these setting states. That is, in the state of FIG. 6A, the controller 301 prohibits the discharge of the sheet S to the discharge tray 211. This completes the processing of this flowchart.

Figure 7 is a flowchart that is executed after the discharge tray 211 is fully loaded. The control based on the flowchart in Figure 7 is executed by the controller 301 shown in Figure 2 based on a program stored in a storage unit such as a ROM or RAM.

After the discharge tray 211 is fully loaded, the controller 301 checks whether the full load detection sensor 405 has turned OFF (S510). If the full load detection sensor 405 is OFF, the controller 301 changes the state of the discharge tray 211 to "empty" (S514) and the state of the discharge outlet 204 to "empty" (S515). A table summarizing these settings is shown in FIG. 6C. In other words, in the state shown in FIG. 6C, the controller 301 permits the discharge of sheets S to the discharge tray 211. The fact that the full load detection sensor 405 has turned OFF means that the sheets S stacked on the discharge tray 211 have been removed by the user, and it can be determined that the full load state has been released.

On the other hand, when the full load detection sensor 405 is ON, the controller 301 checks whether the discharge tray 210 has been removed from the device body 220 (S511). If the discharge tray 210 has not been removed, the controller 301 continues checking S510 and S511. On the other hand, as shown in FIG. 4B, when the discharge tray 210 arranged above the discharge tray 211 is removed from the device body 220, the controller 301 changes the state of the discharge tray 211 to "empty" (S512). Then, the controller 301 changes the state of the discharge tray 210 to "no tray" (S513). A table summarizing these setting states is shown in FIG. 6B. That is, in the state of FIG. 6B, the controller 301 allows the discharge of the sheet S to the discharge tray 211. When the discharge tray 210 is removed, the sheet stacking space of the discharge tray 211 expands as shown in FIG. 4B, and the maximum number of sheets S that can be stacked on the discharge tray 211 increases. Therefore, there is no problem if the controller 301 automatically cancels the full-load state of the discharge tray 211. This completes the processing of this flowchart.

(Explanation of how to select an outlet)
Next, a method for selecting the outlets 203, 204, and 205 by the controller 301 will be described with reference to FIG.

6A, the controller 301 notifies the external device 300 that the discharge tray 211 is full, as described above, and stops the printing operation. Next, when the state of FIG. 6B occurs while the printing operation is stopped after notifying the full load, the controller 301 releases the full load of the discharge tray 211, instructs the sheet sorting device 200 to discharge the sheet S from the discharge outlet 203 to the discharge tray 211, and resumes printing. The reason why the sheet S is discharged from the discharge outlet 203 instead of the discharge outlet 204 here is because the state of the discharge outlet 204 remains "full" in FIG. 6B. In other words, the sheet S is already stacked on the discharge tray 211 up to the vicinity of the discharge outlet 204, and if the sheet S is discharged from the discharge outlet 204, the already stacked sheet S and the newly discharged sheet may collide, resulting in a transport failure. According to the configuration of this embodiment, the full-load detection flag 207 is removed from the device body 220 together with the discharge tray 210, so even if the sheet S is discharged from the discharge port 203 to the discharge tray 211, the full-load detection flag 207 will not get caught and the stackability of the sheet S will not be reduced.

On the other hand, if the state shown in FIG. 6C occurs while the printing operation is stopped after notification of full load, the controller 301 releases the full load from the discharge tray 211, instructs the sheet sorting device 200 to discharge the sheet S from the discharge outlet 204 to the discharge tray 211, and resumes printing. In other words, the discharge outlet from which the sheet S is discharged is different from the state shown in FIG. 6B.

As described above, this embodiment can improve usability when the discharge tray located above the discharge tray that is detected to be fully loaded is removed from the device body.

In the above embodiment 1, the full-load detection flag 207 and the discharge tray 210 are described as being integrated, but they may be removable separately, or only the discharge tray 210 may be removable. In addition, if the full-load detection flag 207 cannot be removed from the device body 220, the full-load detection flag 207 may be configured to be retracted inside the device body 220 so as not to interfere with the discharge of the sheet S from the discharge port 203 to the discharge tray 211.

Example 2
In the first embodiment, a configuration employing a flag-type full-load detection sensor is described. In the present embodiment, a configuration employing a full-load detection sensor that detects the full load of the discharge tray by counting the number of sheets discharged to the discharge tray is described. The main parts are described in the same manner as in the first embodiment, and only the parts different from the first embodiment are described here.

(Configuration diagram of sheet sorting device)
The sheet sorting device 200 in this embodiment will be described with reference to FIG. 8. The difference from the first embodiment is that sheet detection sensors 430, 431, and 432 are provided. The sheet detection sensors 430, 431, and 432 are sensors that detect the presence or absence of sheets S stacked on the discharge trays 210, 211, and 212, respectively. The sheet detection sensors 430, 431, and 432 are, for example, photointerrupters, and output an OFF signal in a light-transmitting state in which no sheets S are stacked on the discharge trays 210, 211, and 212 and the light of the photointerrupter is not blocked by a flag (not shown). Then, the sheet detection sensors 430, 431, and 432 output an ON signal in a light-blocking state in which sheets S are stacked on the discharge trays 210, 211, and 212 and the light of the photointerrupter is blocked by a flag (not shown). Also, unlike the first embodiment, the sheet sorting apparatus 200 of this embodiment is not provided with the full-load detection flags 206, 207, and 208 and the full-load detection sensors 404, 405, and 406.

(Block diagram of control unit and functional configuration)
9 is a block diagram showing the functional configuration of this embodiment. The difference from the first embodiment is that the controller 301 is provided with a counter 320 that counts the number of sheets S discharged to the discharge trays 210, 211, and 212. The counter 320 may be provided in the sorting device control unit 303. The sorting device control unit 303 detects the presence or absence of sheets S stacked on the discharge trays 210, 211, and 212 based on the detection results of the sheet detection sensors 430, 431, and 432.

(Details of the sorting device control section)
10 is a detailed diagram of the sorting device control unit 303 in this embodiment. The sheet detection sensor 430 uses a pull-up 433 and inputs the sensor state (ON signal or OFF signal) to the CPU 400 via a buffer 434. Details of the sheet detection sensors 431 and 432 are the same as those of the sheet detection sensor 430, so a description thereof will be omitted.

(Description of the operation of the sheet sorting device)
Next, the operation of the sheet sorting device 200 in this embodiment will be described with reference to Fig. 11. Here, the case where the discharge tray 211 is fully loaded will be described.

Figure 11 is a flowchart that is executed when a sheet S is discharged to the discharge tray 211. The control based on the flowchart in Figure 11 is executed by the controller 301 shown in Figure 9 based on a program stored in a storage unit such as a ROM or RAM.

While the sheet S is being discharged to the discharge tray 211, the controller 301 checks whether the sheet detection sensor 431 is ON (S520). If the sheet detection sensor 431 is OFF, the controller 301 continues detection. If the sheet detection sensor 431 is ON, the counter 320 counts the number of sheets S discharged to the discharge tray 211. Then, the controller 301 checks whether the counted number has reached a predetermined threshold number (S521). If the counted number has not reached the threshold number, the controller 301 continues discharging the sheet S to the discharge tray 211. If the counted number has reached the threshold number, the controller 301 sets the state of the discharge tray 211 to "full" (S501) and also sets the state of the discharge port 204 to "full" (S502). A table summarizing these setting states is shown in FIG. 6A. In other words, in the state of FIG. 6A, the controller 301 prohibits the discharge of the sheet S to the discharge tray 211. This completes the processing of this flowchart.

Figure 12 is a flowchart that is executed after the discharge tray 211 is fully loaded. The control based on the flowchart in Figure 12 is executed by the controller 301 shown in Figure 9 based on a program stored in a storage unit such as a ROM or RAM.

After the discharge tray 211 is full, the controller 301 checks whether the sheet detection sensor 431 is OFF (S530). If the sheet detection sensor 431 is OFF, the controller 301 changes the state of the discharge tray 211 to "empty" (S514) and changes the state of the discharge port 204 to "empty" (S515). A table summarizing this setting state is shown in FIG. 6C. That is, in the state of FIG. 6C, the controller 301 permits the discharge of sheets S to the discharge tray 211. Then, the controller 301 clears the number of sheets S discharged to the discharge tray 211 (count number) and sets the threshold number to Th2 (S532). Here, the threshold number Th2 is the maximum number of sheets S that can be stacked on the discharge tray 211 when the discharge tray 210 is installed.

On the other hand, if the sheet detection sensor 431 is ON, the controller 301 checks whether the discharge tray 210 has been removed from the device body 220 (S511). If the discharge tray 210 has not been removed, the controller 301 continues checking S510 and S511. On the other hand, if the discharge tray 210 has been removed, the controller 301 changes the status of the discharge tray 211 to "empty" (S512) and changes the status of the discharge tray 210 to "no tray" (S513). A table summarizing this setting state is shown in FIG. 6B. That is, in the state of FIG. 6B, the controller 301 allows the discharge of sheets S to the discharge tray 211. Then, the controller 301 does not clear the number of sheets S discharged to the discharge tray 211 (count number), and sets Th1 to the threshold number (S531). Here, the threshold number Th1 is the maximum number of sheets S that can be loaded on the discharge tray 211 when the discharge tray 210 is removed and the sheet stacking space of the discharge tray 211 is expanded. In other words, the relationship is such that the threshold number Th1>Th2. This completes the processing of this flowchart.

In addition, if the state shown in FIG. 6B occurs while the printing operation is stopped after notification of full load, the controller 301 cancels the full load state of the discharge tray 211, instructs the sheet sorting device 200 to discharge the sheet S from the discharge outlet 203 to the discharge tray 211, and resumes printing. According to the configuration of this embodiment, since the full load detection flag 207 is not provided in the first place, even if the sheet S is discharged from the discharge outlet 203 to the discharge tray 211, the full load detection flag 207 will not be caught and the stackability of the sheet S will not be reduced.

As described above, this embodiment can improve usability when the discharge tray located above the discharge tray that is detected to be fully loaded is removed from the device body.

In the above first and second embodiments, a control has been described in which the full-load state is always released when the discharge tray arranged above the fully-loaded discharge tray is removed from the device body. However, this is not limited to this. The user may be able to select, via an external device 300 or the like, whether or not to release the full load state when the discharge tray arranged above the fully-loaded discharge tray is removed from the device body.

Here, the following cases are possible cases where the user might choose not to release the full load. For example, when small size papers are stacked on the output tray, making it full, the user may remove the output tray located at the top from the device body because it is difficult to see the small size papers when removing them from the output tray. If the full load were released in this case, subsequent papers would be discharged to the output tray while the user was removing the small size papers, which could reduce usability.

The controller 301 or the sorting device control unit 303 may automatically select whether or not to release the full stack when the discharge tray located above the fully loaded discharge tray is removed from the device body, based on information such as the size of the paper instructed to be printed. In other words, in the above example, the controller 301 or the sorting device control unit 303 may select not to release the full stack when a print command is issued for small size paper.

In addition, in the above-mentioned first and second embodiments, when the discharge tray 210 is removed and discharge of the sheets S to the discharge tray 211 is permitted, the sheets S are discharged from the discharge outlet 203 to the discharge tray 211, but this is not limited to this. In order to shorten the distance that the sheets S fall as much as possible and improve the stackability of the sheets S, a predetermined number of sheets S may be discharged from the discharge outlet 204, and then the sheets S may be switched to be discharged from the discharge outlet 203 midway. This is premised on the fact that the discharge outlet 204 is not blocked by the sheets S stacked on the discharge tray 211 at the time when the discharge tray 211 is detected to be fully loaded, and there is a small margin.

In addition, in the above-mentioned first and second embodiments, the case where the discharge tray 210 is removed when the discharge tray 211 is fully loaded is described, but this is not limited to the case. The present invention can also be applied to the case where the discharge tray 211 is removed when the discharge tray 212 is fully loaded. In other words, the fully loaded state of the discharge tray arranged below the removed discharge tray can be released.

In addition, in the above-mentioned first and second embodiments, all of the discharge trays 210, 211, and 212 are described as being removable from the device main body 220, but this is not limiting. Only the discharge tray 210 may be removable, and the discharge trays 211 and 212 may not be removable. In other words, it is sufficient that at least one discharge tray, excluding the discharge tray located at the bottom in the vertical direction, is removable from the device main body 220.

The present invention can also be applied to the case where the discharge tray 212 is removed when the discharge tray 124 of the printer 100 is fully loaded. In this case, the full load detection flag 125 is configured to be removed together with the discharge tray 212.

In addition, in the above-mentioned first and second embodiments, the printer control unit 302 and the sorting device control unit 303 are configured separately, but it is also possible to configure only the printer control unit 302. In that case, the printer control unit 302 may control the sheet sorting device 200.

In addition, in the above-mentioned first and second embodiments, the sheet sorting device 200 may be configured to be detachable from the printer 100, or may be configured to be fixed and integrated with the printer 100.

In addition, in the above-mentioned first and second embodiments, a configuration in which three discharge trays 210, 211, and 212 are provided has been described, but the number of discharge trays is not limited to three. The number of discharge trays may be set according to the environment in which the sheet sorting device 200 is used, the number of users who share the use, or the specifications of the sheet sorting device 200.

In addition, in the above first and second embodiments, a laser beam printer is used as an example, but the image forming device to which the present invention is applied is not limited to this, and may be a printer using another printing method, such as an inkjet printer, or a copier.

200 Sheet sorting device 206, 207, 208 Full load detection flag 210, 211, 212 Discharge tray 301 Controller 303 Sorting device control section 404, 405, 406 Full load detection sensor 407, 408, 409 Tray detection sensor 601, 602, 603 Discharge roller pair

Claims (5)

a first tray that is removable from the device body;
a second tray disposed below the first tray in a vertical direction;
a tray detection means for detecting that the first tray has been removed from the main body of the apparatus;
a stacking amount detection means for detecting that the amount of sheets stacked on the second tray has reached a predetermined amount;
a control means for controlling not to convey the sheets to the second tray when the stack amount detection means detects that the sheet amount has reached the predetermined amount, and a first discharge outlet is formed at a position corresponding to the first tray and a second discharge outlet is formed at a position corresponding to the second tray,
when the stack amount detection means detects that the sheet amount has reached the predetermined amount, the control means interrupts image formation on the sheet and sets a prohibited state in which the sheet is prohibited from being conveyed from the second discharge port to the second tray,
A sheet sorting device characterized in that, when in the prohibited state, the tray detection means detects that the first tray has been removed from the device main body, image formation on the sheet is resumed, image formation is performed on the sheet that was prohibited from being transported from the second discharge outlet to the second tray, and the device enters an permitted state in which transport from the first discharge outlet to the second tray is permitted. The sheet sorting device according to claim 1, characterized in that the load amount detection means includes a sheet detection means for detecting the presence or absence of sheets transported to the second tray, and a counter for counting the number of sheets transported to the second tray, and detects that the sheet amount has reached the predetermined amount when the number of sheets counted by the counter reaches a threshold number while the sheet detection means is detecting sheets. The sheet sorting device according to claim 1 or 2, characterized in that the amount of sheets that can be loaded on the second tray when the first tray is removed from the device body is greater than the amount of sheets that can be loaded on the second tray when the first tray is attached to the device body. 1. A sheet sorting device that is detachable from an image forming apparatus and receives sheets conveyed from the image forming apparatus while attached to the image forming apparatus,
a first tray that is removable from a main body of the sheet sorting device;
a second tray disposed below the first tray in a vertical direction;
a tray detection sensor that outputs a signal in response to the first tray being removed from the apparatus body;
a stacking amount detection sensor that outputs a signal when the amount of sheets stacked on the second tray reaches a predetermined amount, and a first discharge outlet is formed at a position corresponding to the first tray, and a second discharge outlet is formed at a position corresponding to the second tray.
When the load amount detection sensor outputs the signal indicating that the amount of sheets has reached the predetermined amount to a control means of the image forming apparatus, image formation on the sheets is interrupted, and a prohibited state is entered in which the sheets are prohibited from being conveyed from the second discharge port to the second tray,
A sheet sorting device characterized in that, in the prohibited state, when the tray detection sensor outputs a signal to the control means indicating that the first tray has been removed from the device main body, image formation on the sheet is resumed, image formation is performed on the sheet that was prohibited from being transported from the second discharge outlet to the second tray, and the device enters an permitted state in which transport from the first discharge outlet to the second tray is permitted. The sheet sorting device according to claim 4, characterized in that the amount of sheets that can be loaded on the second tray when the first tray is removed from the device body is greater than the amount of sheets that can be loaded on the second tray when the first tray is attached to the device body.

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