Image forming apparatus

An image forming apparatus having an apparatus main body includes an image forming unit provided within the apparatus main body, a stacker portion provided on an upper surface of the apparatus main body, and a sheet storage portion provided between the image forming unit and the stacker portion. The image forming unit forms an image on a sheet. The stacker portion may receive, as stacked sheets, sheets on which images are formed by the image forming unit. The sheet storage portion may store, within the apparatus main body, a sheet on which an image is formed by the image forming unit.

TECHNICAL FIELD

The present invention relates to an image forming apparatus, in particular to an image forming apparatus including a sheet storage portion that stores a sheet on which an image is formed.

BACKGROUND ART

Conventionally, there are image forming apparatuses such as a copying machine, which are provided with a sheet storage portion such as a mail box that stores a sheet on which an image is formed by an image forming unit.

As an image forming apparatus provided with such a sheet storage portion, PTL 1 describes an image forming apparatus including a plurality of sheet storage portions, which are provided below the image forming unit and are assigned to each user, separately from a normal stacker portion, which is provided on the upper surface of the main body of the apparatus and is shared by a plurality of users. In the image forming apparatus described in PTL 1, it is possible to selectively receive only sheets stored in any one of the sheet storage portions by an operation of a user.

CITATION LIST

Patent Literature

However, in the image forming apparatus described in PTL 1, there is a problem that it is difficult for a user to take the sheets out because the stacker portion on the upper surface of the main body of the apparatus and the sheet storage portions below the image forming unit are located at positions largely away from each other.

SUMMARY OF INVENTION

The present invention provides an image forming apparatus including sheet storage portions and a stacker portion in which it is easy for a user to take sheets out.

According to an aspect of the present invention, an image forming apparatus having an apparatus main body includes an image forming unit provided within the apparatus main body and configured to form an image on a sheet, a stacker portion provided on an upper surface of the apparatus main body and configured to receive, as stacked sheets, sheets on which images are formed by the image forming unit, and a sheet storage portion provided between the image forming unit and the stacker portion, wherein the sheet storage portion is configured to store, within the apparatus main body, a sheet on which an image is formed by the image forming unit.

Advantageous Effects of Invention

According to the present invention, the sheet storage portions that store sheets are provided between the image forming unit and the stacker portion on the upper surface of the main body of the apparatus. Therefore, the stacker portion and the sheet storage portions can be arranged near each other, so that a user can easily take any sheets.

DESCRIPTION OF EMBODIMENTS

First Embodiment

FIG. 1shows a schematic cross-sectional view of a monochrome digital printer as an example of an image forming apparatus to which the embodiment is applied.

InFIG. 1, reference numeral100denotes an image forming apparatus main body (hereinafter referred to as an “apparatus main body”). An image forming unit101is included in the apparatus main body100. Reference numeral102denotes a sheet feeding and conveying unit that feeds and conveys a sheet to the image forming unit101. Reference numeral103denotes a fixing unit that fixes an image onto the sheet. Reference numeral124denotes a stacker portion which is provided on the upper surface of the apparatus main body and on which sheets on which an image is formed by the image forming unit are stacked. Reference numerals201,202, and203denote sheet storage portions which store the sheets on which images are formed by the image forming unit101and which is provided between the image forming unit101and the stacker portion124.

Here, the image forming unit101includes a photosensitive drum111that rotates in a clockwise direction inFIG. 1, an exposure apparatus113, and a charging roller112, a developing roller114, and a transfer roller115which are sequentially arranged along a rotation direction of the photosensitive drum111. The image forming unit101forms a toner image on a sheet S by an image forming process.

The sheet feeding and conveying unit102includes a sheet feed cassette105in which a plurality of sheets S used to form an image are stored in a stacked state, a feed roller107, a conveying guide109, and a registration roller110. The fixing unit103includes a fixing roller116, a pressure roller117upward in contact with the fixing roller116, and a conveying roller118.

A sheet S re-conveying path126used to form images on both sides of the sheet S is provided between a set of the image forming unit101and the fixing unit103and the sheet feed cassette105.

In the image forming apparatus of the present embodiment, a plurality of sheet storage portions are vertically stacked. A first sheet storage portion201, a second sheet storage portion202, and a third sheet storage portion203are stacked in order from the above.

Reference numeral204denotes a conveying roller functioning as a conveying unit that conveys a sheet on which an image is formed to the first storage unit201. Similarly, reference numeral205denotes a conveying roller that conveys a sheet to the second storage unit202and reference numeral206denotes a conveying roller that conveys a sheet to the third storage unit203.

Reference numeral120denotes a conveying path switching member whose position can be switched between a first position which is indicated by solid lines inFIG. 1and in which the sheet on which an image is formed is moved toward the sheet storage portions and a second position which is indicated by dashed lines and in which the sheet on which an image is formed is discharged to the stacker portion124. The position of the conveying path switching member120can be switched between the position indicated by solid lines inFIG. 1and the position indicated by dashed lines inFIG. 1by an actuator not shown inFIG. 1. Reference numerals121and123denote reverse rotation rollers which can rotate in a normal direction and a reverse direction and which conveys the sheet to the stacker portion124by rotating in the normal direction and conveys the sheet to the image forming unit101again by rotating in the reverse direction.

When the sheet is discharged to the stacker portion124, the position of the conveying path switching member120is switched to the position indicated by the dashed lines and the sheet is conveyed along a discharge guide122by the reverse rotation roller121and discharged to the stacker portion124by the reverse rotation roller123. As shown inFIG. 1, the stacker portion124is disposed on the upper surface of the apparatus main body and can be used commonly by a plurality of users.

Reference numeral125denotes a stacker full detection lever which detects that the stacker portion124is filled with sheets stacked thereon. When the stacker full detection lever125detects that the stacker portion124is filled with sheets, a control unit not shown inFIG. 1controls so that no image is formed on a sheet until the sheets on the stacker portion124are removed.

When images are formed on both sides of the sheet, a sheet where a toner image is fixed onto one side (front side) thereof is conveyed toward the reverse rotation roller123. After the rear end of the sheet passes through a branch portion127, the reverse rotation rollers121and123are rotated in the reverse direction, so that the sheet is switched back and conveyed to the image forming unit101through the re-conveying path126.

When the sheet is conveyed to the sheet storage portions, the position of the conveying path switching member120is switched to the position indicated by the solid lines and the sheet is conveyed to the sheet storage portion200through a conveying path128.

Reference numerals211and212denote respectively a first switching member and a second switching member for switching a path through which the sheet is conveyed. The positions of the first switching member211and the second switching member212can be switched between the position indicated by solid lines inFIG. 1and the position indicated by dashed lines inFIG. 1by an actuator not shown inFIG. 1.

When the sheet S is conveyed to the first sheet storage portion201, the positions of the first switching member211and the second switching member212are switched to the positions indicated by the solid lines inFIG. 1and held. The sheet on which an image is formed passes through the conveying path128, a conveying guide207, and a conveying guide208in this order, and the sheet is further conveyed to the first sheet storage portion201by a conveying roller204in a face down state, that is, in a state in which the side on which the toner image is formed faces down.

When the sheet S is conveyed to the second sheet storage portion202, the position of the first switching member211is switched to the position indicated by the solid lines inFIG. 1and held and the position of the second switching member212is switched to the position indicated by the dashed lines inFIG. 1and held. The sheet on which an image is formed passes through the conveying path128, the conveying guide207, and a conveying guide209in this order, and the sheet is further conveyed to the second sheet storage portion202by a conveying roller205in the face down state, that is, in the state in which the side on which the toner image is formed faces down.

When the sheet S is conveyed to the third sheet storage portion203, the position of the first switching member211is switched to the position indicated by the dashed lines inFIG. 1and held. The sheet on which an image is formed passes through the conveying path128and a conveying guide210in this order, and the sheet is further conveyed to the third sheet storage portion203by a conveying roller206in the face down state, that is, in the state in which the side on which the toner image is formed faces down.

Next, a detailed configuration of the sheet storage portions will be described with reference toFIG. 2. In the image forming apparatus of the present embodiment, a plurality of sheet storage portions are vertically stacked. Each sheet storage portion has the same configuration, so that here, the configuration of the first sheet storage portion201will be described.

The sheet conveyed to the first sheet storage portion by the conveying roller204is temporarily stacked on a stacking surface231and stored. Whether or not sheets are placed on the stacking surface231is detected by a sheet presence/absence detection unit not shown in the drawings. Reference numeral233denotes a push-out unit that pushes a conveying direction upstream end (rear end) of the stored sheets and pushes out a part of the sheets on the downstream side (front end) from a discharge port234to the outside of the apparatus main body100. The sheets are pushed out from the discharge port234by the push-out unit233, so that the user can receive the sheets. In the present embodiment, the length of the stacking surface231is set to a length in which the front end of a sheet does not protrude from the discharge port234even when a longest sheet that can be stored in the sheet storage portion is stacked.

When a sheet is conveyed to the first storage unit201, the push-out unit233is positioned at a stacking position indicated by solid lines inFIG. 2at which the push-out unit233does not prevent the sheet from being conveyed and stacked. On the other hand, when push-out unit233pushes out the stored sheets, the push-out unit233moves toward the discharge port234along a sheet discharge direction and moves to a push-out position (sheet discharge position) indicated by dashed lines.

FIGS. 3A and 3Bare perspective views of the push-out unit233.FIG. 3Ashows a case in which the push-out unit233is located at the stacking position andFIG. 3Bshows a case in which the push-out unit233is located at the push-out position. The push-out unit233includes two sheet rear end pressure hooks233aand233balong the sheet width direction in order to prevent the sheets S from being rotated when the sheets S are discharged. The push-out unit233pushes out the sheets, the sheet rear end pressure hooks233aand233bpush the upstream end of the sheets S to discharge the sheets. The push-out unit233is connected to an actuator239and the push-out unit233reciprocates between the stacking position and the push-out position along the sheet discharge direction when the actuator239is driven in a normal direction and a reverse direction.

FIG. 4is a block diagram showing a control unit and a functional configuration of the image forming apparatus shown inFIGS. 1, 2, 3A, and 3B.

The image forming apparatus100includes an image forming apparatus control unit501as a control unit. The image forming apparatus control unit501includes a video controller502and an image forming apparatus control CPU503.

The video controller502communicates with an external device500such as a host computer and receives print data (including control information such as code data based on a predetermined program language, image data, and the like). Also, the video controller502specifies a print condition (paper discharge port and the like) created from the print data to the image forming apparatus control CPU503through a serial I/F and issues a print instruction to the image forming apparatus control CPU503. Also, the video controller502instructs the image forming apparatus control CPU503to discharge sheets from the sheet storage portions200on the basis of user information inputted from an operation display unit240and user information obtained from an ID card by an ID card authentication unit241.

The image forming apparatus control CPU503controls printing according to the print condition received from the video controller502as well as detects an error such as a jam of the image forming apparatus100on the basis of information from the jam detection sensor504and notifies the video controller502of the error. The image forming apparatus control CPU503controls a sheet conveying mechanism506and performs feed conveyance and discharge conveyance of a sheet as well as controls the image forming unit101and the fusing unit103and performs an image forming operation and a fusing operation on the sheet. The image forming apparatus control CPU503controls a sheet storage portion control mechanism507including conveying rollers204to206and conveys the sheet on which an image is formed to a sheet storage portion. The image forming apparatus control CPU503controls the sheet push-out unit233by an instruction from the video controller502and performs control to discharge sheets stored in a sheet storage portion by using information of a connected sheet discharge sensor505.

Next, an operation of the sheet storage portions will be described with reference toFIG. 5. When a user performs a print operation from the external device500to the apparatus main body100, the user can select whether the sheet is discharged to the stacker portion124or the sheet is temporarily stored in a sheet storage portion from the external device.

If the user selects that the sheet is stored in a sheet storage portion, the control unit detects a sheet storage portion in which no sheet is stored on the basis of detection results of the sheet presence/absence detection units provided for each sheet storage portion and determines a conveyance destination of the sheet.

For example, when the conveyance destination of the sheet is determined to be the first sheet storage portion201, the switching member is switched and the sheet is conveyed onto the stacking surface231of the first sheet storage portion201.

Since the control unit has information indicating who's job is stored in what sheet storage portion, it is possible to select a sheet storage portion in which sheets have been already stored as a storage destination if the job is performed by the same user. The user need not select a sheet storage portion to which a job of the user is stored and a sheet is automatically stored in a sheet storage portion to which the sheet can be stored.

In the present embodiment, sheets stored in each sheet storage portion are stored so that the sheets cannot be taken out from the outside of the apparatus main body. The sheets stored in a sheet storage portion are pushed out by the push-out unit by a discharge instruction from a user, so that a discharge operation is started. Examples of the discharge instruction include pressing a discharge operation start button on the operation display unit provided on the apparatus main body, ID card authentication, and issuing a discharge operation start command from an external device connected to the image forming apparatus. Specific methods for issuing the discharge operation start command on an operation unit are as follows: For example, names and personal ID numbers of users who store a job in a sheet storage portion are shown on the operation display unit240provided on the apparatus main body100shown inFIG. 6and a user operates a portion corresponding to the user, so that the user can issue the discharge instruction. Or, when a user is authenticated by using an ID card, an ID card authentication unit241is attached to the apparatus main body and ID information is acquired from the ID card authentication unit241, so that the sheet discharge instruction can be issued.

When the video controller502receives the sheet discharge instruction, the video controller502issues the sheet discharge instruction to the image forming apparatus control CPU503and the image forming apparatus control CPU503controls the actuator to move the push-out unit from the stacking position to the push-out position.

At this time, information related to users who issued a print instruction of the sheets stored in the sheet storage portions is stored by a storage unit. Since the storage unit stores information indicating who's job is stored in what sheet storage portion, a user need not recognize the sheet storage portion in which the job of the user is stored and the user can receive his or her job when issuing the sheet discharge instruction.

In the first embodiment, each sheet storage portion is provided with an individual actuator that drives the push-out unit of the sheet storage portion. Therefore, even when jobs of the same user are stored in a plurality of sheet storage portions, it is possible to discharge sheets so that the user can receive sheets at the same time by driving each actuator. Hence, even when jobs of the same user are stored in a plurality of sheet storage portions, it is possible to receive sheets from a plurality of sheet storage portions at the same time by displaying one portion that indicates the user on the operation display unit and by only operating the one portion. Similarly, in the method of the ID card authentication, it is possible to receive sheets at the same time from a plurality of sheet storage portions in which sheets corresponding to user information of the ID card are stored.

The third sheet storage portion203inFIG. 5shows a state in which sheets are pushed out and discharged. An upstream end B1of a sheet bundle B stacked on the stacking surface231is pushed out by the push-out unit233. Thereby, the sheet bundle B moves in the downstream direction and passes through the discharge port236, and the conveying direction downstream end B2of the sheet bundle B is exposed to the outside of the apparatus main body.

FIG. 6shows a perspective view of the apparatus main body100at this time. A printed job J of a plurality of users is stacked on the stacker portion124and the downstream end B2of the sheet bundle B discharged from the third sheet storage portion203is exposed from the discharge port236. A user can receive the sheet bundle of the user by catching the downstream end B2exposed to the outside of the apparatus and pulling out the sheet bundle B.

At this time, it is desired that the amount of exposure of the sheet bundle B is set so that the center of gravity of the sheet bundle B does not go beyond the discharge port236. This is because if the center of gravity of the sheet bundle B is pushed out to a position beyond the discharge port236, the sheet bundle B slips out of the discharge port236before the user receives the sheet bundle B.

A discharge sensor, which is not shown in the drawings and which functions as a detection unit to detect that a user pulls out the sheet bundle B, is provided near the discharge ports234to236. When the discharge sensor not shown in the drawings detects that a user pulls out the sheet bundle B, the push-out unit233moves from the push-out position to the stacking position. Further, the sheet presence/absence detection unit detects that no sheet is stacked on the sheet storage portion, so that the control unit deletes sheet storage information and the sheet storage portion becomes in a state in which the sheet storage portion can store new sheets.

As shown inFIG. 7A, the sheet storage portions201to203can integrally rotate around a fulcrum of rotation X. Further, as shown inFIG. 7B, it is possible to take out a process cartridge150after rotating the sheet storage portions. The fulcrum of rotation X is provided on a downstream side of the conveying rollers that conveys a sheet to the sheet storage portions in the sheet conveying direction.

In this way, the sheet storage portions201to203can be integrally opened, so that even when a jam occurs in any one of the sheet storage portions201to203, the jam can be removed by the same operation. Further, it is not necessary to provide a mechanism for individually opening each of the sheet storage portions201to203, so that the jam can be removed by a simple configuration.

As described above, according to the first embodiment, the sheet storage portions are provided above the image forming unit101and below the stacker portion124. Therefore, it is possible to arrange the stacker portion124and the discharge ports of the sheet storage portions to be near each other. Thus, when a user receives any sheet, the user can receive the sheet without being forced into an unnatural posture. Further, since the stacker portion124is disposed on the upper surface of the apparatus, the sheets stacked on the stacker portion can be easily seen and easily taken out.

In the first embodiment, a configuration is described in which three sheet storage portions are provided. However, the number of the sheet storage portions is not limited to three. The number of the sheet storage portions and the number of sheets that can be stored in each sheet storage portion may be set according to an environment in which the apparatus main body is used, the number of users who use the apparatus main body, and the specification of the apparatus main body.

Second Embodiment

Next, a second embodiment of the present invention will be described with reference toFIG. 8. In the second embodiment, only the direction in which the sheets are discharged from the sheet storage portions is different from that of the first embodiment and the other configuration is the same as that of the first embodiment, so that the description will be appropriately omitted.

In the second embodiment, the direction in which the sheet is discharged to the stacker portion124by the reverse rotation roller123and the direction in which the sheets are discharged from the sheet storage portions by the push-out unit are perpendicular to each other. Accordingly, the direction in which the sheet feed cassette105is pulled out and the position of the operation display unit240are changed.

In the same manner as in the first embodiment, also in the second embodiment, it is possible to arrange the stacker portion124and the discharge ports234to236of the sheet storage portions to be closely near each other. Therefore, when a user receives any sheet, the user can receive the sheet without being forced into an unnatural posture.

Third Embodiment

Next, a third embodiment of the present invention will be described with reference toFIGS. 9 and 10.

In the third embodiment, there are two sheet storage units300aand300bin each of which three sheet storage portions are piled vertically. The sheet storage units300aand300bhave the same configuration. Reference numeral400denotes a stacker unit for stacking sheets on the stacker portion124. The sheet storage units300aand300band the stacker unit400are removably stacked on a main body unit130.

FIG. 10is a diagram showing these units with a vertical gap in between for explaining each connection portion. The upper surface of the main body unit130includes positioning holes131and132to which the sheet storage unit300aor300bor the stacker unit400is connected. Also, the upper surface of the main body unit130includes a drawer connector133. Positioning pins134and135and a drawer connector136are provided on the lower surface of the sheet storage units300aand300b.

When the positioning pins134and135are inserted into the positioning holes131and132, the main body unit130and the sheet storage units300aand300bare positioned relative to each other. At this time, the drawer connectors133and136are connected to each other. The drawer connectors include a signal line, a power line, and a ground line, so that the drawer connectors can transmit signals and supply electric power.

Similarly, positioning holes131and132and a drawer connector133are provided on the upper surface of sheet storage units300aand300band positioning pins134and135and a drawer connector136are provided on the lower surface of the stacker unit400.

The main body unit130includes a sheet conveying path140through which a sheet on which an image is formed is conveyed to the sheet storage unit or the stacker unit. The sheet on which an image is formed is conveyed vertically from the upper surface of the main body unit130.

In this way, the sheet storage units and the stacker unit are removably stacked, so that the number of the sheet storage units attached to the apparatus main body100can be changed according to an operating environment. For example, the following change can be made: When the apparatus main body100is shared by several users, only one sheet storage unit is mounted, and when the apparatus main body100is shared by tens of users, a plurality of sheet storage units are mounted. Further, when the user does not need the sheet storage unit, the stacker unit400can be mounted immediately above the apparatus main body130.

Fourth Embodiment

Next, a fourth embodiment of the present invention will be described with reference toFIGS. 11A, 11B, 12A, 12B, and 12C. In the fourth embodiment, only the configuration of the conveying path through which the sheet on which an image is formed is conveyed and the position at which the switching member is provided are different from those of the first embodiment and the other configuration is the same as that of the first embodiment, so that the description will be appropriately omitted.

As shown inFIGS. 11A and 11B, the conveying path through which the sheet conveyed by the conveying roller118passes branches to a first conveying path40through which the sheet is conveyed to the reverse rotation roller123and to a second conveying path41through which the sheet is conveyed to the sheet storage portions. As shown inFIG. 11A, when the conveying path switching member42is located at a first position, the sheet is conveyed to the reverse rotation roller123. As shown inFIG. 11B, when the conveying path switching member42is located at a second position, the sheet is conveyed to the sheet storage portions through the second conveying path. The position of the conveying path switching member42can be switched between the first position and the second position by an actuator not shown inFIG. 1.

An operation in which images are formed on both sides of the sheet will be described with reference toFIGS. 12A, 12B, and 12C. As shown inFIG. 12A, the position of the conveying path switching member42is switched and the preceding sheet S1on a first side of which an image is formed is conveyed to the reverse rotation roller123. As shown inFIG. 12B, after the rear end of the sheet S1passes through a branch portion R, the reverse rotation rollers121and123are rotated in the reverse direction, so that the sheet S1is switched back and conveyed to the image forming unit101through a reverse path600. As shown inFIG. 12C, even when the preceding sheet S1is passing through the reverse path600, the following sheet S2can be conveyed to the sheet storage portions through the second conveying path.

Therefore, according to the fourth embodiment, even when the preceding sheet is being conveyed for reverse printing, the following sheet can be conveyed to the sheet storage portions.

Although the embodiments of the present invention have been described in detail, the first to the fourth embodiments can be combined with each other and used.

Modified Embodiment

In the first to the fourth embodiments, a configuration is described in which each sheet storage portion has an actuator that drives the push-out unit. However, the number of the actuators can be smaller than that of the sheet storage portions. For example, a drive transmission switching unit that can selectively switch ON/OFF of a drive transmission state of a drive from the actuator may be provided so that a plurality of push-out units can be moved by one actuator. Thereby, the number of the actuators can be reduced.

In the first to the fourth embodiments, a configuration is described in which the rear end pressure hooks push out the sheets. However, in the present invention, the configuration of the push-out unit should not be limited to this configuration. For example, a pair of detachable rollers as shown inFIG. 13may be used as a push-out unit. When a sheet is conveyed to the sheet storage portion, the rollers are away from each other as shown by a pair of rollers250, so that the rollers do not prevent the sheet from being conveyed. When the sheet bundle is discharged, the rollers come into contact with the upper surface and the lower surface of the stored sheets, respectively, and nip the sheet bundle as shown by a pair of rollers251. Further, the rollers rotate in directions indicated by arrows shown around a pair of rollers252, so that the sheets stored in the sheet storage portion are discharged.

In the first to the fourth embodiments, a configuration is described in which each sheet storage portion has one discharge port. However, the present invention should not be limited to this. For example, as shown inFIG. 14, the sheet storage portions are merged at a merged portion260on the downstream side in the conveying direction and the sheet storage portions may have only one shared discharge port261. In this case, even when the jobs of a user are separately stored in a plurality of sheet storage portions, the user can receive the plurality of jobs of the user as one sheet bundle by driving the push-out units of the plurality of sheet storage portions at the same time.

This application claims the benefit of Japanese Patent Application No. 2012-094054, filed Apr. 17, 2012, which is hereby incorporated by reference herein in its entirety.

REFERENCE SIGNS LIST