JP7516105B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming device.

Patent document 1 describes a configuration in which an image forming device that forms images, such as a laser beam printer, has multiple paper output trays.

For example, when an image is formed on the top surface of a sheet, there is an output tray that is an output section where the sheet passes through a transport path that turns the sheet over after the image is formed, and the sheet is discharged with the image side facing down. If the face is the side on which the image is formed, this output tray is called a face-down (hereinafter also referred to as FD) tray because the sheet is discharged with the face facing down. On the other hand, when an image is formed on the top surface of a sheet, there is an output tray that is an output section where the sheet passes through a transport path that does not turn the sheet over after the image is formed, and the sheet is discharged with the image side facing up. This output tray is called a face-up (hereinafter also referred to as FU) tray because the sheet is discharged with the face facing up.

The FU tray may be configured to be openable and closable. In this configuration, when the FU tray is closed, it serves as a guide section that guides sheets to the FD tray, and when it is open, it serves as a paper output tray on which sheets can be loaded without guiding them to the FD tray.

The user can select the sheet output section depending on the application. If the sheet output section selected by the user does not match the open/closed state of the FU tray, the open/closed state of the FU tray is notified to the user.

Patent Publication 2015-110455

However, when printing by forming an image on multiple sheets and discharging them to the FD tray, if the FU tray is opened before the last sheet of the multiple sheets is discharged to the FD tray, the stack of sheets will be separated into a stack on the FD tray and a stack on the FU tray. Furthermore, the stacking order of the sheets discharged to the FD tray will be reversed from the stacking order of the sheets discharged to the FU tray.

For this reason, for example, as the number of sheets discharged to the FU tray increases, when the sheets discharged to the FU tray are bundled with the sheets discharged to the FD tray, it becomes more time-consuming to rearrange the stacking order of the sheets discharged to the FU tray. This could lead to a decrease in usability.

The invention of this application has been made in consideration of the above situation. It aims to reduce the effort required to rearrange the stacking order of sheets even if the FU tray is opened before the last sheet of multiple sheets is discharged to the FD tray.

In order to solve the above problems, the present invention has the following configuration.

an image forming means for forming an image on a sheet;
a sheet feeding means for feeding a sheet to the image forming means;
a first discharge section in which the sheet on which the image is formed by the image forming means is conveyed through a first discharge conveyance path and then discharged face-down with the formed image facing downward;
a second discharge section which can be switched between a closed position and an open position, and in which a sheet on which an image has been formed by the image forming means is discharged face-up with the formed image facing upward after being transported through a second discharge transport path, the second discharge section being a guide section which guides the sheet to the first discharge section in the closed position, and being a sheet discharge section on which sheets can be stacked without guiding the sheet to the first discharge section in the open position;
an open/close signal output means for outputting a first signal when the second paper discharge unit is closed and outputting a second signal when the second paper discharge unit is open;
A message output means for outputting a message;
a series of printing operations for feeding a plurality of sheets by the paper feeding means, forming an image on only one side of each of the plurality of sheets by the image forming means, and discharging the plurality of sheets with the image formed on only one side to the first paper discharge section; and a control means for controlling the message output means,
The control means
starting the printing operation with the second paper discharge unit closed;
when the second signal is output by the open/close signal output means before the last sheet of the plurality of sheets is discharged to the first sheet discharge section, stopping the sheet feeding means from newly feeding a sheet;
causing the image forming means to form an image on a sheet that had already been fed by the sheet feeding means before the second signal was output by the open/close signal output means;
outputting, by the message output means, a message for prompting the user to perform an operation of turning over the sheets discharged to the second discharge section and stacking the uppermost sheet on the sheets stacked in the first discharge section after the sheets that have already been fed and on which an image has been formed are discharged to the second discharge section, and switching the second discharge section to a position for a closed state;
When the first signal is output by the open/close signal output means after the printing operation is paused,
an image forming device that causes said image forming means to form an image following an image formed on the sheet last fed by said feeding means before said printing operation is stopped;

As described above, according to the present invention, even if the FU tray is opened before all of the multiple sheets are ejected to the FD tray, the effort of rearranging the stacking order of the sheets can be reduced.

Schematic diagram of an image forming apparatus FIG. 1A is a control block diagram of an entire printer control system according to a first embodiment; FIG. 1B is a control block diagram of hardware related to sheet transport control according to the first embodiment; (a) to (c) are explanatory diagrams of the FU tray open/close sensor 117; (d) are explanatory diagrams of the REG sensor 106; FIG. 1A is a diagram illustrating the stacking order of sheets discharged onto the FD tray 115; FIG. 1B is a diagram illustrating the stacking order of sheets discharged onto the FU tray 116; and FIG. 1C is a diagram illustrating the rearrangement of the stacking order of sheets discharged onto the FU tray 116. Flowchart of processing related to the first embodiment 1A to 1E are explanatory diagrams of messages relating to the first to third embodiments. Flowchart of processing according to the second embodiment Flowchart of processing related to the third embodiment

First Embodiment
<Configuration of Image Forming Apparatus>
FIG. 1 is a schematic diagram of an image forming apparatus 10 according to the present embodiment.

First, the image forming means for performing the image forming process will be described. In FIG. 1, the photosensitive drum 122 is composed of an organic photosensitive body or an amorphous silicon photosensitive body, and is rotated clockwise at a predetermined peripheral speed (process speed). The peripheral surface of the photosensitive drum 122 is uniformly charged to a predetermined polarity and potential by the charging roller 123. Then, the laser light output from the optical device 109 is reflected by the laser light reflecting mirror 108 and irradiated onto the charged peripheral surface of the photosensitive drum 122, thereby performing scanning exposure and forming an electrostatic latent image corresponding to the image information. At this time, the laser light is modulated (on/off conversion) in response to the time-series electric digital pixel signal of the target image information input from an image signal generating device (not shown) such as an image reading device or a computer.

The electrostatic latent image thus formed on the photosensitive drum 122 corresponding to the target image is developed into a toner image by the developer 121 attaching toner charged to the same polarity as the charge applied by the charging roller 123. The formation of the electrostatic latent image starts according to the timing when the registration sensor 106 (hereinafter referred to as the REG sensor 106) detects the leading edge of the sheet.

Next, the sheet feeding means will be described. Sheets stacked in the paper feed tray 100 are picked up by the paper feed roller 102 and fed one by one to the conveying roller 104 by the separation roller 103. At this time, the presence or absence of a sheet in the paper feed tray 100 is detected by the sheet detection sensor 101. The sheet fed to the conveying roller 104 is conveyed to the conveying roller 105. At this time, the sheets stacked in the paper feed tray 100 are fed through a paper feed conveying path that conveys the sheets to the conveying roller 105 with their top faces facing downwards when stacked. The paper feed conveying path at this time is also referred to as the first paper feed conveying path. The paper feed tray 100 is also referred to as the first paper feed section.

The toner image developed on the photosensitive drum 122 is transferred to a sheet. At this time, the transfer roller 107 transfers the toner image from the photosensitive drum 122 to the sheet by supplying a charge of the opposite polarity to the toner from the back surface of the sheet. The sheet onto which the toner image has been transferred in this manner is separated from the photosensitive drum 122 and transported to the fixing device 130. The fixing device 130 is composed of a heater 132, a thermistor 131 that detects the heater temperature, a fixing sleeve 133, and a pressure roller 134. The fixing device 130 fixes the toner image on the sheet to the sheet by the heat from the heater 132 and the pressure from the fixing nip formed by the fixing sleeve 133 and the pressure roller 134.

As described above, each member involved in the series of image forming processes that form an image on a sheet is referred to as an image forming means. Furthermore, each member involved in feeding a sheet to the image forming means is referred to as a paper feeding means.

The sheet with the fused toner is transported by the FU roller 111 driven by a DC brushless motor 622 and the FD roller 112 driven by a stepping motor 623, and is ejected onto the FD tray 115.

Next, the sheet discharge section will be described. The image forming device 10 has an FD tray 115 for face-down discharge (hereinafter also referred to as FD discharge) and an FU tray 116 for face-up discharge (hereinafter also referred to as FU discharge). The discharge transport path to the FD tray 115 and the discharge transport path to the FU tray 116 are different.

The discharge transport path to the FD tray 115 is the transport path through which the sheet travels from the FU roller 111 to the FD roller 112 before being stacked on the FD tray 115. The discharge transport path to the FD tray 115 is also referred to as the first discharge transport path. When a sheet with an image formed on its upper surface is transported along the first discharge transport path, it is discharged to the FD tray 115 with the image surface facing downward (face down) (FD). The FD tray discharge sensor 125 can record the number of sheets discharged to the FD tray 115. The FD tray 115 is also referred to as the first discharge section.

The FU tray 116 is an opening/closing member that can be switched between an open position and a closed position. When the FU tray 116 is in the closed position, it serves as a guide section that guides sheets to the FD tray 115. When the FU tray 116 is in the open position, it serves as a paper output tray on which sheets can be stacked, without serving as a guide section that guides sheets to the FD tray 115.

The discharge transport path to the FU tray 116 is the transport path from the FU roller 111 to when the sheet is loaded onto the FU tray 116. The discharge transport path to the FU tray 116 is also referred to as the second discharge transport path. When a sheet with an image formed on its upper surface is transported along the second discharge transport path, it is discharged to the FU tray 116 with the image surface facing upward (face up) (FU). The FU tray 116 is also referred to as the second discharge section.

The FU tray open/close sensor 117 serves as an open/close signal output means that outputs a first signal when the FU tray 116 is closed and outputs a second signal when the FU tray 116 is open. The CPU 601 detects the open/close state according to the first signal or the second signal output by the FU tray open/close sensor 117. In other words, the FU tray open/close sensor 117 functions as a detection means that detects whether the FU tray 116 is open or closed. The detailed function will be described later.

Next, a case where sheets are fed from the MP tray 140 (Multi-Purpose Tray) for manually feeding sheets as another sheet feeding means will be described. The MP tray 140 is an opening/closing member that can be switched between an open position and a closed position. When the MP tray 140 is in the open position, it serves as a feed port for feeding sheets, and when the MP tray 140 is in the closed position, it does not serve as a feed port for feeding sheets. When feeding sheets from the MP tray 140, the MP tray 140 is switched to the open position and sheets are loaded on it. The MP tray 140 is also referred to as the second feed section.

When feeding a sheet from the MP tray 140, the CPU 601 drives the MP feed solenoid 621 via the I/O port 606 for a predetermined time to rotate the MP feed roller 142. The MP feed roller 142 feeds the sheets stacked on the MP tray 140 to the MP separation roller 143. The MP separation roller 143 separates the sheets fed by the MP feed roller 142 into a single sheet and transports them to the transport roller 105. The sheet transported to the transport roller 105 is transported to the photosensitive drum 122. As with the sheet fed from the paper feed tray 100, a toner image is formed and fixed on the sheet transported to the photosensitive drum 122, and the sheet is discharged to the FU tray 116 or the FD tray 115.

The presence or absence of sheets loaded on the MP tray 140 is detected by an MP paper presence/absence sensor 141. Sheets loaded on the MP tray 140 are transported to the image forming unit 120 through a paper feed transport path that transports the sheets to the transport rollers 105 with their top faces facing up when loaded. The paper feed transport path used when feeding sheets from the MP tray 140 is also referred to as the second paper feed transport path.

Similarly, when feeding a sheet from the optional paper feed tray 200, 300, the optional paper feed rollers 202, 302 feed the sheet to the optional separation rollers 203, 303. At this time, like the paper feed tray 100 and MP tray 140, the presence or absence of sheets stacked on the optional paper feed trays 200, 300 is detected by the sheet detection sensors 201, 301, respectively. The optional separation rollers 203, 303 separate the conveyed sheets into a single sheet and convey them to the optional conveying rollers 204, 304. The sheet conveyed to the optional conveying rollers 204, 304 is conveyed to the image forming unit 120. The operation after being conveyed to the image forming unit 120 is the same as when the sheet is fed from the paper feed tray 100 or MP tray 140.

An operation panel 626 is also provided on the top of the image forming device 10. The operation panel 626 is composed of a liquid crystal panel that displays images and text to provide information such as instructions to the user, and a keypad that accepts instructions from the user. In this embodiment, the operation panel 626 is also referred to as a message output means that outputs information to notify the user of a message.

<Printer Control System Configuration>
2A is a block diagram for explaining the overall configuration of the printer control system of this embodiment. As long as the functions of this embodiment can be executed, the system may be a single device, a system consisting of multiple devices, or a system in which processing is performed by connecting via a network such as a LAN or WAN.

In FIG. 2(a), the host computer 200 includes a CPU 201. The CPU 201 executes document processing including a mixture of figures, images, characters, tables (including spreadsheets, etc.) based on a document processing program stored in the program ROM of the ROM 203 or in the external memory 210. In this embodiment, the CPU 201 processes image information using, for example, an application, a graphic engine, and a printer driver.

The CPU 201 performs overall control of each device connected to the main bus 204. The program ROM of the ROM 203 or the external memory 210 stores an operating system program (hereinafter referred to as OS) which is the control program of the CPU 201. The font ROM of the ROM 203 or the external memory 210 stores font data and the like used during the above-mentioned document processing. The data ROM of the ROM 203 or the external memory 210 stores various data used during the above-mentioned document processing and the like. The RAM 202 functions as the main memory, work area, etc. of the CPU 201.

The keyboard controller 205 controls key input from a keyboard 208 or a pointing device (not shown). The display controller 206 controls the display on a display 209. The user inputs the desired printing operation to the host computer 200 by performing operations such as selecting a printing operation using the keyboard 208 or a pointing device (not shown) as an input means.

The disk controller 207 controls access to the external memory 210. The external memory 210 is a hard disk (HD), a flexible disk (FD), etc. The external memory 210 stores a boot program, various applications, font data, user files, edit files, a printer control command generation program (hereinafter referred to as a printer driver), etc.

The CPU 201 executes a process of expanding (rasterizing) the outline font to the display information RAM set on the RAM 202, for example. The rasterizing process enables WYSIWYG (What You See Is What You Get) on the display 209. WYSIWYG means that the CPU 201 displays the final finish on the display 209, so that the user can edit while checking the final finish. The CPU 201 also opens various windows registered based on commands instructed by the user using a mouse cursor (not shown) on the display 209, and executes various data processing. When executing a printing operation, the user opens a window related to the settings of the printing operation, and sets the printer settings and the printing processing method for the printer driver, including the selection of the printing mode. The image information generated by such processing is output from the host computer 200 to the printer device 212.

The printer device 212 is the image forming device 10 shown in FIG. 1, and forms an image on a sheet based on image information input from the host computer 200 according to the electrophotographic process described above. The printer controller 213 is controlled by the CPU 214. The CPU 214 outputs an image signal, which is second image information, to the printing unit (printer engine) 221 connected to the main bus 204 based on a control program stored in the program ROM of the ROM 216. The program ROM of the ROM 216 stores the control program of the CPU 214. The font ROM of the ROM 216 stores font data used when generating the output information, and the data ROM of the ROM 216 stores information used on the host computer.

The CPU 214 can communicate information with the host computer 200 using the bidirectional interface (interface) 211 via the input unit 218, and notifies the host computer 200 of information in the printer device 212. At this time, the input unit 218 functions as a receiving means for receiving information including, for example, the first image information from the host computer 200.

RAM 215 functions as the main memory and work area of CPU 214, and is configured so that the memory capacity can be expanded by an optional RAM (not shown) connected to an expansion port (not shown). RAM 215 is used as an output information expansion area, an environmental data storage area, an NVRAM, etc.

The printer device 212 in this embodiment may be connected to an external memory (not shown) as an option. This external memory (not shown) stores font data, emulation programs, form data, etc. Furthermore, the printer device 212 in this embodiment may be able to connect multiple external memories (not shown) that store, in addition to the built-in fonts, option cards, and programs that interpret printer control languages of different language systems.

Figure 2(b) is a block diagram showing the hardware configuration related to sheet transport control as a software function realized by the printing unit 221 of this embodiment.

The CPU 601 communicates with the ROM 603, RAM 604, I/O port 606, and serial communication port 607 via a communication bus 605. The CPU 601 controls the printing unit 221 by executing computer programs stored in the ROM 603 and RAM 604. The CPU 601 executes the programs stored in the ROM 603, obtains the results of calculations during execution, and stores the results of calculations in the RAM 604. Note that the CPU 601 and an MPU (not shown) equipped with multiple processors, such as multi-cores, may control the printing unit 221 using the multiple processors. Hereinafter, the CPU 601 is also referred to as a control means.

The storage unit of the printing unit 221 is composed of one or more memories such as ROM 603 and RAM 604, and stores various information such as computer programs for performing various operations described below and communication parameters for wireless communication. The storage unit in this embodiment may be a memory such as ROM 603 or RAM 604. The storage unit in this embodiment may also be a storage medium such as a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a non-volatile memory card, or a DVD.

The MP paper presence sensor 141 is controlled by the CPU 601 via the MP paper presence sensor input circuit 610 and the I/O port 606.

The MP feed solenoid 621 is controlled by the CPU 601 via the MP feed solenoid drive circuit 611 and the I/O port 606. The MP feed solenoid 621 is driven for a predetermined time, causing the MP feed roller 142 to rotate. As the MP feed roller 142 rotates, the sheets stacked on the MP tray 140 are transported to the MP separation roller 143.

The DC brushless motor 622 is controlled by the CPU 601 via the DC brushless motor drive circuit 612 and the I/O port 606. The DC brushless motor 622 drives the FU roller 111.

The stepping motor 623 is controlled by the CPU 601 via the stepping motor drive circuit 613 and the I/O port 606. The stepping motor 623 drives the FD roller 112.

The FU tray open/close sensor 117 is controlled by the CPU 601 via the FU tray open/close sensor input circuit 614 and the I/O port 606.

The operation of the REG sensor 106 is controlled by the CPU 601 via the REG sensor input circuit 615 and the I/O port 606.

The serial communication port 607 is connected to the operation panel control circuit 616. The operation panel 626 is controlled by the CPU 601 via the operation panel control circuit 616. The CPU 601 obtains information entered by the user using the liquid crystal panel or keypad of the operation panel 626 by controlling the serial communication port 607.

<Method of detecting the open/closed state of the FU tray 116 by the FU tray open/close sensor 117>
A method for the FU tray open/close sensor 117 to detect the open/close state of the FU tray 116 in this embodiment will be described below. Fig. 3A is a perspective view of the image forming apparatus 10 with the FU tray 116 open. Fig. 3B is a cross-sectional view of the image forming apparatus 10 as viewed from the direction of the arrow shown in Fig. 3A. Fig. 3C is a perspective view of each member of the FU tray open/close sensor 117.

As shown in Figures 3(b) and 3(c), the FU tray open/close sensor 117 is composed of a support member 301, a cam member 302, a flag member 303, and a photointerrupter 304 (omitted from Figure 1). The photointerrupter 304 is an example of an optical sensor used as a detection unit, and can output a different signal depending on whether or not light is blocked by the flag member 303.

The support member 301 is attached to the FU tray 116 and rotates together with the FU tray 116 when the FU tray 116 rotates to the open position. The support member 301 supports the cam member 302.

The cam member 302 converts the rotational movement of the support member 301 into the up and down movement of the flag member 303.

When the FU tray 116 is in the closed position, the flag member 303 blocks the sensor light from the light-emitting portion 304a of the photointerrupter 304. When the FU tray 116 is in the open position, the flag member 303 is pushed upward by the cam member 302, and the sensor light from the light-emitting portion 304a is received by the light-receiving portion 304b. Note that the arrangement of the light-emitting portion 304a and the light-receiving portion 304b may be reversed.

The photointerrupter 304 outputs different signals by switching between two light receiving states: a state in which the sensor light of the light emitting unit 304a is received by the light receiving unit 304b, and a state in which the light is blocked by the flag member 303 and not received. That is, when the FU tray 116 is closed, the photointerrupter 304 is in a state in which the sensor light of the light emitting unit 304a is blocked by the flag member 303 and not received by the light receiving unit 304b. When the FU tray 116 is open, the photointerrupter 304 is in a state in which the sensor light of the light emitting unit 304a is not blocked by the flag member 303 and is received by the light receiving unit 304b.

As described above, when the FU tray 116 is closed, the FU tray open/close sensor 117 outputs a LOW signal to the CPU 601 via the FU tray open/close sensor input circuit 614 and the I/O port 606. This signal is also referred to as the first signal. Upon receiving the LOW signal (first signal), the CPU 601 detects that the FU tray 116 is closed.

In addition, when the FU tray 116 is open, the FU tray open/close sensor 117 outputs a HIGH signal to the CPU 601 via the FU tray open/close sensor input circuit 614 and the I/O port 606. This signal is also referred to as the second signal. Upon receiving the HIGH signal (second signal), the CPU 601 detects that the FU tray 116 is open.

In this way, the FU tray open/close sensor 117, which outputs a first signal when the FU tray 116 is closed and outputs a second signal when the FU tray 116 is open, is also referred to as an open/close signal output means.

* Photointerrupter 304 ⇒ When photointerrupter 304 is blocked by the flag member 303 ⇒ A LOW signal (first signal) is output. Photointerrupter 304 ⇒ When photointerrupter 304 is not blocked by the flag member 303 ⇒ A HIGH signal (second signal) is output. CPU 601 ⇒ Receives a LOW signal = Detects that the FU tray 116 is closed. CPU 601 ⇒ Receives a HIGH signal = Detects that the FU tray 116 is open. <Operation when the FU tray 116 is opened during printing>
The operation when the FU tray 116 is opened during printing in which single-sided printing is performed on each of a plurality of sheets will be described below. First, the paper feed means feeds sheets to the image forming means when the FU tray 116 is closed. The image forming means forms an image on only one side of each of the plurality of sheets, and the sheets on which the image is formed only on one side are discharged to the FD tray 115. When performing this series of printing operations, if the FU tray 116 is opened before the last sheet of the plurality of sheets is discharged to the FD tray 115, all subsequent pages are discharged to the FU tray 116. If the page order needs to be taken into consideration, it becomes necessary to rearrange the order of the sheets discharged to the FU tray 116 when the user collects the stack of discharged sheets into one.

Next, the stacking order of sheets will be explained. When sheets are discharged to the FD tray 115, the side on which the image is formed is faced down, and the succeeding sheet is stacked on top of the previous sheet, so the stacking order of sheets is as shown in FIG. 4(a). In other words, when the stack of sheets discharged to the FD tray 115 after the printing operation is completed is turned over, the pages are arranged in ascending order. However, when sheets are discharged to the FU tray 116, the side on which the image is formed is faced up, and the succeeding sheet is stacked on top of the previous sheet, so the stacking order of sheets is as shown in FIG. 4(b). In other words, the stack of sheets discharged to the FU tray 116 after the printing operation is completed is arranged in descending order.

When combining the stack of sheets discharged to the FU tray 116 with the stack of sheets discharged to the FD tray 115, a sheet rearrangement operation is required as shown in FIG. 4(c). First, the stack of sheets discharged to the FU tray 116 is turned over so that the side on which the image is formed faces downward. Next, of the turned-over stack of sheets, the topmost sheets are stacked one by one on top of the stack of sheets discharged to the FD tray 115.

In this way, when the page order needs to be taken into consideration, it becomes necessary to rearrange the order of the sheets discharged to the FU tray 116 when combining the stack of sheets discharged to the FU tray 116 with the stack of sheets discharged to the FD tray 115.

In this embodiment, even if the FU tray 116 is opened before the last sheet of multiple sheets is discharged to the FD tray 115, the effort required to rearrange the stacking order of the sheets can be reduced.

<Method of storing the number of fed sheets and the number of discharged sheets>
A method for storing the number of fed sheets and the number of discharged sheets will be described below. In this embodiment, sheets stacked on the sheet feed tray 100 are picked up by the sheet feed roller 102 and conveyed one by one to the conveyance roller 104 by the separation roller 103. In this embodiment, the REG sensor 106 detects the leading edge to the trailing edge of the sheet conveyed one by one to detect whether the sheet has passed through the REG sensor 106. In this embodiment, the REG sensor 106 detects the sheet that has passed through, and the CPU 601 stores the number of sheets that have passed through the REG sensor 106 in the RAM 604, thereby making it possible to count the number of fed sheets.

The FD tray discharge sensor 125 detects whether a sheet has been discharged to the FD tray 115 by detecting the leading edge to the trailing edge of the sheet. The CPU 601 stores the number of sheets that have passed the FD tray discharge sensor 125 in the RAM 604, thereby making it possible to count the number of sheets discharged to the FU tray 116.

The number of sheets discharged to the FU tray 116 is calculated by the CPU 601 by subtracting the number of sheets discharged to the FD tray 115 stored in the RAM 604 from the number of fed sheets stored in the RAM 604.

For example, when five sheets have been discharged onto the FD tray 115 and the FU tray 116 is opened after the sixth sheet has been fed, the sixth sheet on which an image has been formed is discharged onto the FU tray 116. At this time, the REG sensor 106 detects that six sheets have been fed and stores this in the RAM 604, and the FD tray discharge sensor 125 detects that five sheets have been discharged and stores this in the RAM 604. Therefore, the CPU 601 calculates that the number of sheets discharged onto the FU tray 116 is one.

Also, if the spacing between sheets is narrow, when five sheets have been discharged to the FD tray 115 and the FU tray 116 is opened, an image may have already been formed on the sixth sheet and up to the seventh sheet may have been fed. In this case, after the sixth sheet on which the image has been formed is discharged to the FU tray 116, images are finally formed on the seventh sheet and the seventh sheet is discharged to the FU tray 116. The REG sensor 106 detects that seven sheets have been fed and stores this in the RAM 604, and the FD tray discharge sensor 125 detects that five sheets have been discharged and stores this in the RAM 604. For this reason, the CPU 601 calculates that the number of sheets discharged to the FU tray 116 is two.

In this way, the CPU 601 calculates the number of sheets discharged to the FU tray 116 by subtracting the number of sheets discharged to the FD tray 115 from the number of sheets fed.

<Method of detecting a sheet by the REG sensor 106 and the FD tray paper discharge sensor 125>
The following describes the detection method when the REG sensor 106 and the FD tray paper discharge sensor 125 detect a sheet. As shown in Fig. 3D, the REG sensor 106 is composed of a photointerrupter 310 and a flag member 311. The flag member 311 is rotatably provided near the photointerrupter 310. The photointerrupter 310 outputs different signals depending on two types of light receiving state changes: a state in which the sensor light of the light emitting portion 310a is received by the light receiving portion 310b, and a state in which the light is blocked by the flag member 311 and not received.

When there is no sheet in the transport path, the flag member 311 comes into contact with the transport path under its own weight. At this time, the flag member 311 is in a position that does not block the sensor light from the light-emitting portion 310a of the photointerrupter 310, and the sensor light is received by the light-receiving portion 310b. On the other hand, when a sheet is transported to the REG sensor 106, the flag member 311 rotates by coming into contact with the sheet, blocking the sensor light from the light-emitting portion 310a of the photointerrupter 310. The arrangement of the light-emitting portion 310a and the light-receiving portion 310b may be reversed.

As described above, when there is no sheet on the transport path, the REG sensor 106 outputs a HIGH signal to the CPU 601 via the REG sensor input circuit 615 and the I/O port 606. The CPU 601, which receives the HIGH signal, detects that there is no sheet on the transport path. Furthermore, when a sheet is transported to the REG sensor 106, the REG sensor 106 outputs a LOW signal to the CPU 601 via the REG sensor input circuit 615 and the I/O port 606. The CPU 601, which receives the LOW signal, detects that a sheet has been transported to the REG sensor 106.

The FD tray paper discharge sensor 125 and the fixing sensor 110 have the same configuration as the REG sensor 106, so their explanation will be omitted.

<Processing when the FU tray 116 is opened during printing>
Next, specific processing performed by the CPU 601 in this embodiment will be described with reference to the flowchart in Fig. 5. In this embodiment, a series of printing operations is performed in which the paper feed unit feeds sheets to the image forming unit, the image forming unit forms an image on only one side of each of a plurality of sheets, and the sheets with the image formed on only one side are discharged to a first paper discharge unit.

If the FU tray open/close sensor 117 detects that the FU tray 116 is open before the last sheet of the multiple sheets is discharged to the FD tray 115, the CPU 601 stops feeding new sheets and pauses the printing operation. The message output means then prompts the user to remove the sheet discharged to the FU tray 116 and then switch the FU tray 116 to a closed position. When the FU tray open/close sensor 117 detects that the FU tray 116 is closed, the image forming means forms an image again starting from the image next to the image formed on the sheet last discharged to the FD tray 115 before the printing operation was paused. This printing operation is called a reprint.

In S400, the CPU 601 starts a printing operation to eject paper onto the FD tray 115 while the FU tray 116 is closed, and then proceeds to S401.

In S401, the next step branches depending on whether the last sheet of the multiple sheets has been discharged to the FD tray 115. If the last sheet of the multiple sheets has been discharged to the FD tray 115 in S401 (YES), the flowchart ends. If the last sheet of the multiple sheets has not been discharged to the FD tray 115 in S401 (NO), proceed to S402.

In S402, the FU tray open/close sensor 117 detects whether the FU tray 116 is open or not. In S402, the process returns to S401 until the FU tray open/close sensor 117 detects that the FU tray 116 is open (until the FU tray 116 is opened). In S402, if the FU tray open/close sensor 117 detects that the FU tray 116 is open before the last sheet of the multiple sheets is discharged to the FD tray 115, the process proceeds to S403.

In S403, if there are subsequent pages after the timing at which the FU tray open/close sensor 117 detects that the FU tray 116 is open, the CPU 601 stops feeding new sheets by the feed roller 102 and proceeds to S404. If there are no subsequent pages, the feed means has finished feeding all sheets, so the process proceeds to S404. By stopping the feeding of new sheets, the CPU 601 can reduce the number of sheets that are discharged to the FU tray 116, which is not the intended discharge destination. Also, by stopping the feeding of new sheets, the CPU 601 can reduce the number of sheets that need to be rearranged when assembling the sheets into a single stack.

In S404, the CPU 601 detects the presence or absence of a sheet on the transport path from when the sheet is fed to when it is discharged to the FU tray 116. For example, the REG sensor 106 and the fixing sensor 110 are used to detect a sheet present on the transport path from the feed roller 102 to the transport roller 105, the transfer roller 107, the fixing device 130, and the FU roller 111. In S404, for example, when a sheet is detected by the REG sensor 106 and the fixing sensor 110, the CPU 601 waits for the detected sheet to be discharged to the FU tray 116. That is, first, the FU tray 116 is opened, and the FU tray open/close sensor 117 detects that the FU tray 116 is open. If there is a sheet that has already been fed by the feed roller 102 and not discharged to the FD tray 115 before this timing, the CPU 601 causes the image forming means to form an image and discharge the sheet to the FU tray 116. At this time, the number of sheets discharged to the FU tray 116 is calculated by subtracting the number of sheets discharged to the FD tray 115 from the number of sheets fed.

In S405, the CPU 601 stops all motors involved in sheet transport and image formation to pause the printing operation.

In S406, the CPU 601 displays a message (a) on the operation panel 626. The content of the message displayed on the operation panel 626 at this time is, for example, a message as shown in FIG. 6(a). Message (a) is a message for urging the user to "remove the sheets discharged onto the FU tray 116 and switch the FU tray 116 to the closed position." Message (a) also includes an OK button.

In S407, if the CPU 601 obtains information that the OK button has been pressed by the user, it proceeds to the next step.

In S408, the CPU 601 displays a message (b) on the operation panel 626. The content of the message displayed on the operation panel 626 at this time is, for example, a message as shown in FIG. 6(b). Message (b) is a message for notifying the user that "sheets discharged to the FU tray 116 will be reprinted" when restarting the printing operation. Message (b) also has an OK button.

In S409, if the CPU 601 obtains information that the user has pressed the OK button, it removes the display of message (b) and proceeds to S410.

In S410, the FU tray open/close sensor 117 detects that the FU tray 116 is closed, and the process proceeds to S411.

In S411, the CPU 601 issues operation instructions to each of the sheet transport mechanism 511, the fixing device 130, and the image forming unit 120, and resumes the printing operation using the FD tray 115 as the paper discharge unit. At this time, images are formed again starting from the image following the image formed on the sheet last discharged to the FD tray 115 before the printing operation was paused. Note that the number of sheets discharged to the FD tray 115 is the number of sheets that have passed the FD tray paper discharge sensor 125.

By using the control described above, when the printing operation is completed, all sheets in the printing operation are loaded onto the FD tray 115 in the correct order.

Note that messages (a) and (b) do not necessarily have to be displayed on the operation panel 626. For example, the contents of messages (a) and (b) may be notified to the user by voice using a reading function. Also, the contents of messages as shown in messages (a) and (b) may be notified to the user by the illumination pattern of an LED lamp.

In this embodiment, a case has been described in which different images are formed on one side of multiple sheets, and the FU tray 116 is switched to an open position while the sheets are being ejected to the FD tray 115. However, it is not necessarily the case that different images are formed. The same image may also be formed on one side of multiple sheets.

Furthermore, in this embodiment, a case where an image is formed on one side of multiple sheets has been described. However, images may be formed on both sides of multiple sheets.

Summary of the First Embodiment
As described above, in this embodiment, a case has been described in which, with the FU tray 116 closed, an image is formed on only one side of each of a plurality of sheets, and the sheets are discharged to the FD tray 115. If the FU tray open/close sensor 117 detects that the FU tray 116 is open before the last sheet of the plurality of sheets is discharged to the FD tray 115, the CPU 601 stops feeding a new sheet and pauses the printing operation. By the CPU 601 stopping feeding a new sheet and pausing the printing operation, it is possible to prevent sheets from being continuously discharged to the FU tray 116, and it is possible to reduce the number of sheets discharged to the FU tray 116 that is not the intended discharge destination. Next, the message output unit prompts the user to remove the sheets discharged to the FU tray 116 and switch the FU tray 116 to a position in the closed state. When the FU tray open/close sensor 117 detects that the FU tray 116 is closed, an image is formed again from the image next to the image formed on the sheet last discharged to the FD tray 115 before the image forming unit paused the printing operation. In other words, a reprint is performed. This operation eliminates the need for the user to rearrange the stacking order of the sheets discharged to the FU tray 116 and reload them on the FD tray 115, and allows the stack of sheets on the FD tray 115 to be organized in the stacking order.

Second Embodiment
In the first embodiment, when the FU tray open/close sensor 117 detects that the FU tray 116 is open before the last sheet of the multiple sheets is discharged to the FD tray 115, the CPU 601 stops feeding a new sheet. Then, the printing operation is paused. Next, the message output unit prompts the user to remove the sheet discharged to the FU tray 116 and then to switch the FU tray 116 to a closed position. When the FU tray open/close sensor 117 detects that the FU tray 116 is closed, a printing operation is performed in which an image is formed again by the image forming unit from the image next to the image formed on the sheet last discharged to the FD tray 115 before the printing operation is paused. In other words, reprinting is performed.

In this embodiment, a case is described in which the user is prompted to stack and consolidate the sheets discharged to the FU tray 116 on top of the stack of sheets stacked on the FD tray 115.

In this embodiment, a series of printing operations is performed in which the paper feed means feeds sheets to the image forming means, the image forming means forms an image on only one side of each of the multiple sheets, and the sheets with the image formed on only one side are discharged to the first paper discharge section.

The control in this embodiment will be described below with reference to the flowchart shown in FIG. 7. The same configurations as those in the previous embodiment will be assigned the same numbers and their descriptions will be omitted. In addition, the image formation process and hardware configuration are also the same as those in the first embodiment, so their descriptions will be omitted.

Steps S400 to S405 are the same as in the first embodiment, so the explanation will be omitted.

In S601, the CPU 601 displays a message (c) on the operation panel 626. The content of the message displayed on the operation panel 626 at this time is, for example, a message as shown in FIG. 6(c). Message (c) is a message to prompt the user to "turn over the stack of sheets discharged to the FU tray 116 and place the top sheet one by one on top of the stack of sheets loaded on the FD tray 115." Message (c) also includes an OK button.

If the CPU 601 obtains information in S602 that the OK button has been pressed by the user, it deletes message (c) and proceeds to S603.

The message displayed on the operation panel 626 in S601 assumes that two or three sheets have been discharged to the FU tray 116. However, in this embodiment, it is also acceptable for only one sheet to be discharged, and the message may state, "Turn over the sheet discharged to the FU tray 116 and place it on top of the stack of sheets stacked on the FD tray 115."

The CPU 601 may switch the contents of the message displayed on the operation panel 626 depending on whether or not only one sheet has been discharged to the FU tray 116. Furthermore, if there are no subsequent pages, steps S602 and onward may be omitted.

In S603, the CPU 601 displays a message (d) on the operation panel 626. The content of the message displayed on the operation panel 626 at this time is, for example, a message as shown in FIG. 6(d). Message (d) is a message for urging the user to perform the operation of "close the FU tray 116." Message (d) also includes an OK button. If the CPU 601 obtains information that the OK button has been pressed by the user, it may erase the display of message (d).

In S604, the FU tray open/close sensor 117 detects that the FU tray 116 is closed, and the process proceeds to S605.

In S605, the CPU 601 issues operation instructions to each of the sheet transport mechanism 511, the fixing device 130, and the image forming unit 120, and resumes the printing operation paused in S405 with the FD tray 115 as the discharge destination. At this time, the FD tray 115 also contains sheets discharged to the FU tray 116. Therefore, the image forming unit forms an image starting from the image next to the image formed on the sheet fed by the paper feeding unit before the printing operation was paused. Note that the number of sheets fed is the number of sheets that have passed the REG sensor 106.

By using the control described above, when the printing operation for all of the multiple sheets is completed, all of the sheets in the printing operation are loaded onto the FD tray 115 in the correct order.

Note that messages (c) and (d) do not necessarily have to be displayed on the operation panel 626. For example, the contents of messages (c) and (d) may be notified to the user by voice using a reading function. Also, the contents of messages such as those shown in messages (c) and (d) may be notified to the user by the illumination pattern of an LED lamp.

In this embodiment, a case has been described in which different images are formed on one side of multiple sheets and the FU tray 116 is switched to an open position while the sheets are being discharged to the FD tray 115. However, it is not necessarily the case that different images are formed. The same image may be formed on one side of multiple sheets. In this case, in S601, the message (c) does not need to urge the user to correct the stacking order of the sheets that have been discharged to the FU tray 116 and combine them with the stack of sheets stacked on the FD tray 115. The message may urge the user to stack the stack of sheets that have been discharged to the FU tray 116 on top of the stack of sheets stacked on the FD tray 115.

In this embodiment, a case has been described in which different images are formed on one side of multiple sheets, and the FU tray 116 is switched to an open position while the sheets are being ejected to the FD tray 115. However, it is not necessarily the case that different images are formed. The same image may also be formed on one side of multiple sheets.

Furthermore, in this embodiment, a case where an image is formed on one side of multiple sheets has been described. However, images may be formed on both sides of multiple sheets.

Summary of the Second Embodiment
As described above, in this embodiment, a case has been described in which an image is formed on only one side of each of a plurality of sheets with the FU tray 116 closed, and the sheets are discharged to the FD tray 115. If the FU tray open/close sensor 117 detects that the FU tray 116 is open before the last sheet of the plurality of sheets is discharged to the FD tray 115, the CPU 601 stops feeding a new sheet and pauses the printing operation. By the CPU 601 stopping feeding a new sheet and pausing the printing operation, it is possible to prevent sheets from being continuously discharged to the FU tray 116, and it is possible to reduce the number of sheets discharged to the FU tray 116 that is not the intended discharge destination. Next, the message output unit prompts the user to stack the sheets discharged to the FU tray 116 on top of the stack of sheets stacked on the FD tray 115 and consolidate them. This operation makes it possible to consolidate the discharged sheets into one stack while preventing the stacking order of the sheets from being disturbed. Furthermore, it is possible to prevent a sheet from being wasted by being discharged to the FU tray 116 that is not the intended discharge tray.

Third Embodiment
In the first embodiment, when the FU tray open/close sensor 117 detects that the FU tray 116 is open before the last sheet of the multiple sheets is discharged to the FD tray 115, the CPU 601 stops feeding a new sheet. Then, the printing operation is paused. Next, the message output means prompts the user to remove the sheet discharged to the FU tray 116 and then switch the FU tray 116 to the position of the closed state. Then, when the FU tray open/close sensor 117 detects that the FU tray 116 is closed, the image forming means performs a printing operation to form an image again from the image next to the image formed on the sheet last discharged to the FD tray 115 before the printing operation is paused. That is, reprinting is performed. Also, in the second embodiment, when the FU tray open/close sensor 117 detects that the FU tray 116 is open before the last sheet of the multiple sheets is discharged to the FD tray 115, the CPU 601 stops feeding a new sheet. Then, the printing operation is paused. Next, the user is prompted to stack and consolidate the sheets discharged onto the FU tray 116 on top of the stack of sheets stacked on the FD tray 115 .

When the CPU 601 reprints the sheets discharged to the FU tray 116 as in the first embodiment, the user does not need to perform cumbersome operations that require consideration of the sheet orientation and stacking order. Also, when the user operates to combine a stack of sheets into one as in the second embodiment, there is an advantage that the sheets discharged to the FU tray 116 are not wasted. Whether the first embodiment or the second embodiment is better depends on the user's convenience. Therefore, in this embodiment, the user can select whether the CPU 601 performs reprinting as in the first embodiment, or prompts the user to perform an operation to combine the discharged sheets into one stack without reprinting as in the second embodiment.

In the third embodiment, the paper feed means also feeds sheets to the image forming means, and the image forming means forms an image on only one side of each of the multiple sheets, which are then discharged to the FD tray 115, to execute a series of printing operations. The control in this embodiment will be described below using the flowchart shown in FIG. 8. The same components as in the previous embodiment are given the same numbers and will not be described. The image forming process and hardware configuration are also the same as in the first and second embodiments, and will not be described.

S400 to S405 are the same as in the first and second embodiments, and therefore will not be described. In S701, the CPU 601 displays a message (e) on the operation panel 626. The content of the message displayed on the operation panel 626 at this time is, for example, a message as shown in FIG. 4(e). Message (e) is a message that notifies the user that the FU tray 116 has been opened, and allows the user to select whether or not to reprint the sheet discharged to the FU tray 116.

In S702, if the CPU 601 acquires information that the user has selected YES (if reprinting has been selected), the process proceeds from S406 to S411. S406 to S411 are the same as in the first embodiment, and therefore a description thereof will be omitted. In S702, if the CPU 601 acquires information that the user has selected NO (if reprinting has been selected), the process proceeds from S601 to S605. S601 to S605 are the same as in the second embodiment, and therefore a description thereof will be omitted.

<Summary of the Third Embodiment>
As described above, in this embodiment, a case has been described in which, with the FU tray 116 closed, an image is formed on only one side of each of a plurality of sheets, and the sheets are discharged to the FD tray 115. When the FU tray 116 is opened and the FU tray open/close sensor 117 detects that the FU tray 116 is open, the CPU 601 stops feeding new sheets and pauses the printing operation. By the CPU 601 stopping feeding new sheets and pausing the printing operation, it is possible to prevent sheets from being continuously discharged to the FU tray 116, and it is possible to reduce the number of sheets discharged to the FU tray 116 that is not the intended discharge destination. In addition, the CPU 601 can allow the user to select whether to perform reprinting as in the first embodiment, or to prompt the user to perform an operation to collect the discharged sheets into one bundle without performing reprinting as in the second embodiment. This function can accommodate both cases, where the user wants to increase convenience by performing reprinting, and where the user wants to avoid wasting sheets that have been discharged to the FU tray 116, thereby improving usability.

111 FU roller 112 FD roller 115 FD tray 116 FU tray 117 FU tray open/close sensor 125 FD tray paper discharge sensor 213 Printer controller 626 Operation panel

Claims (5)

an image forming means for forming an image on a sheet;
a sheet feeding means for feeding a sheet to the image forming means;
a first discharge section in which the sheet on which the image is formed by the image forming means is conveyed through a first discharge conveyance path and then discharged face-down with the formed image facing downward;
a second discharge section which can be switched between a closed position and an open position, and in which a sheet on which an image has been formed by the image forming means is discharged face-up with the formed image facing upward after being transported through a second discharge transport path, the second discharge section being a guide section which guides the sheet to the first discharge section in the closed position, and being a sheet discharge section on which sheets can be stacked without guiding the sheet to the first discharge section in the open position;
an open/close signal output means for outputting a first signal when the second paper discharge unit is closed and outputting a second signal when the second paper discharge unit is open;
A message output means for outputting a message;
a series of printing operations for feeding a plurality of sheets by the paper feeding means, forming an image on only one side of each of the plurality of sheets by the image forming means, and discharging the plurality of sheets with the image formed on only one side to the first paper discharge section; and a control means for controlling the message output means,
The control means
starting the printing operation with the second paper discharge unit closed;
when the second signal is output by the open/close signal output means before the last sheet of the plurality of sheets is discharged to the first sheet discharge section, stopping the sheet feeding means from newly feeding a sheet;
causing the image forming means to form an image on a sheet that had already been fed by the sheet feeding means before the second signal was output by the open/close signal output means;
outputting, by the message output means, a message for prompting the user to perform an operation of turning over the sheets discharged to the second discharge section and stacking the uppermost sheet on the sheets stacked in the first discharge section after the sheets that have already been fed and on which an image has been formed are discharged to the second discharge section, and to switch the second discharge section to a position for a closed state;
When the first signal is output by the open/close signal output means after the printing operation is paused,
an image forming device that causes said image forming means to form an image following an image formed on the sheet last fed by said feeding means before said printing operation is stopped; The control means
2. The image forming apparatus according to claim 1 , wherein the number of sheets fed by said sheet feeding means and the number of sheets discharged to said first sheet discharging section are stored. the control means starts the printing operation in a state in which the second paper discharge unit is closed,
when the second signal is output by the open/close signal output means before the last sheet of the plurality of sheets is discharged to the first sheet discharge section, stopping the sheet feeding means from newly feeding a sheet;
causing the image forming means to form an image on a sheet that had already been fed by the sheet feeding means before the second signal was output by the open/close signal output means;
outputting, by the message output means, a message that allows the user to select, when the printing operation is resumed after the sheet that has already been fed and on which an image has been formed is discharged to the second paper discharge section, whether to cause the image forming means to form an image again from the image next to the image formed on the sheet that was last discharged to the first paper discharge section before the printing operation was suspended, or to cause the image forming means to form an image from the image next to the image formed on the sheet that was last fed by the paper feed means before the printing operation was suspended,
2. The image forming apparatus according to claim 1, wherein , after the printing operation is paused, if the first signal is output by the open/close signal output means, the printing operation is resumed. The control means
When it is selected in response to the message output by the message output means to cause the image forming means to form an image again from the image next to the image formed on the sheet that was last discharged to the first paper discharge unit before the printing operation was paused,
4. The image forming apparatus according to claim 3, wherein the message output means outputs a message prompting an operation to remove the sheet discharged to the second paper discharge section and an operation to switch the second paper discharge section to a closed position. The control means
When it is selected in response to the message output by the message output means to cause the image forming means to form an image following the image formed on the sheet last fed by the paper feeding means before the printing operation is stopped,
The image forming apparatus according to claim 3, characterized in that the message output means outputs a message prompting an operator to turn over the sheets discharged to the second paper discharge section and place the top sheet on top of the sheets stacked in the first paper discharge section, and to switch the second paper discharge section to a closed position.

Images