JP2000255876A - Sheet discharge device and image forming device using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change the number of stages of trays, and the positions thereof in dependence upon a used condition by a user. SOLUTION: A discharge sheet loading device 300 is composed of an elevating means 309 provided in a body so that it can be elevated up and down by a drive means, a plurality of trays 307a, 307b, 307c which are selectively arranged at a plurality of attaching positions 313 vertically located in the elevating means, for loading thereon sheets discharge from a sheet discharge part 404, and a control means for controlling the drive means so as to lift a selected one of the plurality of sheets up to a position where the sheets which are discharged from the discharge part are received.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge sheet which is provided in a main body of an image forming apparatus such as a printer, a copier, a facsimile, and a composite device thereof and receives a sheet discharged from the main body of the image forming apparatus. Loading equipment,
The present invention relates to an image forming apparatus provided with the sheet stacking device in a main body.

[0002]

2. Description of the Related Art In recent years, with the increase in processing speed and the amount of information, the image forming apparatus has been required to supply not only a sheet feeding apparatus provided in the main body of the image forming apparatus but also a large-capacity sheet as an option. There is an increasing need to connect the device to the main body of the image forming apparatus.

Along with this, a discharged sheet which is a post-processing device such as a stacker capable of stacking a large number of sheets on which images are formed, a sorter having a plurality of trays, and sorting the sheets on each tray. The necessity of connecting a loading device is also increasing, and various types of practical use have been put to practical use.

[0004]

However, in the conventional discharged sheet stacking apparatus, the number of trays for stacking sheets and the arrangement of the trays cannot be changed while being set at the time of design or at the time of shipment. It was difficult to adjust to the form.

Further, it is necessary to design and manufacture a dedicated apparatus for each application, such as a stacker capable of stacking a large amount of sheets and a sorter for sorting and stacking the sheets on a large number of trays.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a discharge sheet stacking apparatus capable of changing the number and position of trays in accordance with a use situation of a user, and an image forming apparatus provided with the apparatus.

[0007]

According to a first aspect of the present invention, there is provided a discharge sheet stacking device which is provided on a main body so as to be movable up and down, and which is driven up and down by a driving means. A plurality of trays that are selectively provided in the main body and that stack sheets discharged from a sheet discharge portion of the main body; and that the drive unit is controlled to select a tray from among the plurality of trays from the sheet discharge unit. Control means for raising and lowering the discharged sheet to a position for receiving the sheet;
It is characterized by having.

In the discharge sheet stacking device, the tray is provided at a selected one of a plurality of mounting positions of the elevating means.

The control means controls the driving means to raise and lower the elevating means, and stops when the selected tray is moved to a position for receiving the sheet discharged from the sheet discharging unit. The tray holds the sheets discharged from the sheet discharge unit.

The discharge sheet stacking device according to the present invention is provided with mounting tray detecting means for detecting a tray provided on the elevating means corresponding to the plurality of mounting positions, wherein the driving means has a pulse motor, The control means stores in advance the distance between the plurality of mounting positions in association with the pulse number of the pulse motor, and the tray is provided based on the pulse number and a detection signal of the mounting tray detection means. Storing the position, controlling the rotation of the pulse motor,
When the number of pulses corresponding to the tray selected from among the plurality of trays is reached, lifting of the lifting / lowering means is stopped.

In the above discharge sheet stacking apparatus, the tray is provided at a selected mounting position among a plurality of mounting positions of the elevating means. At this time, the mounting tray detecting means corresponding to the mounting position where the tray is provided operates.

The control means stores in advance the distance between the plurality of mounting positions in correspondence with the number of pulses for driving the pulse motor. Based on the detection signal of the mounting tray detecting means, the mounting position where the loading tray is mounted is detected,
The distance between the mounting positions where the stacking trays are mounted can be known from the number of pulses, and the control means stores the number of pulses.

The control means controls the rotation of the pulse motor when raising and lowering the stacking tray, and among the plurality of trays,
When the number of pulses corresponding to the selected tray is reached, lifting of the lifting means is stopped.

Thus, the selected tray among the plurality of trays can be moved up and down to a position for receiving the sheet discharged from the sheet discharge section.

The discharge sheet stacking device of the present invention includes a passing tray detecting means for detecting the tray when the elevating means provided with the tray moves up and down, and the control means raises and lowers the elevating means, The passing tray detecting means detects the tray, stores the number of the trays, again detects the trays by the passing tray detecting means, counts the number of the trays, and selects a tray selected from the plurality of trays. The lifting operation of the lifting means is stopped when the count number corresponding to (1) is reached.

In the discharge sheet stacking device, the tray is provided at a selected mounting position among a plurality of mounting positions of the elevating means.

The control means raises and lowers the elevating means, detects the tray by the passing tray detecting means, and stores the number of trays. When a tray is selected by the user, the control unit raises and lowers the elevating unit, counts the number of trays while detecting the tray by the passing tray detection unit, and reaches a count number corresponding to the selected tray. At this time, the lifting of the lifting means is stopped.

As a result, the tray selected from the plurality of trays stops at the position for receiving the sheet discharged from the sheet discharge section.

In this discharge sheet stacking apparatus, the number of tray detection means is smaller than that of the above-mentioned discharge sheet stacking apparatus, because the passing tray detecting means detects the tray when the elevating means provided with the tray moves up and down.

The discharge sheet stacking apparatus according to the present invention includes tray count detection means for detecting the tray when the lifting means provided with the tray moves up and down, the drive means has a pulse motor, and the control means Is moved up and down, the tray count is detected by the tray count detection means, the number of the trays is stored, and
The tray count detecting unit detects the trays, counts the number of the trays, and when the count number corresponding to the selected tray among the plurality of trays is reached, stops the lifting operation of the lifting / lowering unit. I have.

In the discharge sheet stacking device, the tray is provided at a selected mounting position among a plurality of mounting positions of the elevating means.

The control means raises and lowers the elevating means, makes the tray count detecting means detect the trays, and stores the number of trays. At the same time, the distance between the trays is stored in correspondence with the number of pulses of the pulse motor.

When the tray is selected by the user,
The control means raises and lowers the elevating means and counts the trays while detecting the trays by the tray count detecting means. At the same time, the number of pulses is counted.

When the count of the tray reaches the count corresponding to the selected tray and the number of pulses reaches the number of pulses corresponding to the selected tray, the control means stops raising and lowering of the lifting / lowering means. Let it.

As a result, the tray selected from the plurality of trays stops at the position for receiving the sheet discharged from the sheet discharge section.

Thereafter, as sheets are stacked on the selected tray, the control means lowers the tray. During that time, the control means is counting the number of pulses.
When the pulse number approaches the pulse number of the upper tray of the selected tray, or when the pulse number is reached, the control means:
It is determined that the sheets on the selected tray are full, and then the discharge of the sheets discharged from the main body of the discharge sheet stacking device is stopped.

As described above, this discharge sheet stacking device
When the selected tray is full of sheets, the discharge of sheets is stopped using the stored pulse number.

An image forming apparatus according to the present invention includes: an image forming means for forming an image on a sheet; and any one of the discharged sheet stacking apparatuses for discharging a sheet on which an image is formed by the image forming means. It is characterized by having.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 to FIG.
Description will be made based on 0.

(Image Forming Apparatus) FIG. 1 is a schematic front sectional view of an image forming apparatus 100 provided with a discharge sheet stacking apparatus 300 according to a first embodiment of the present invention in a main body 130.

The main body 13 of the image forming apparatus 100
0 indicates not only the discharged sheet stacking device 300 of the first embodiment but also the discharged sheet stacking device 40 of the second and third embodiments.
0,500 can be similarly connected.

However, the main body 130 of the image forming apparatus 100
In addition, the discharge sheet stacking device 400 according to the second or third embodiment,
The drawing to which the reference numeral 500 is connected is the same as that in FIG.

The main body 130 of the image forming apparatus 100 is placed on a sheet feeding apparatus 200 having casters 219, and the sheet outlet 1 of the main body 130 of the image forming apparatus 100 is provided.
A discharge sheet stacking device 300 is connected to the side of 19.

The discharge sheet stacking apparatus 300 has a caster 310, and can be easily separated from the main body 130 of the image forming apparatus 100 when a jam occurs or when the fixing unit 115 is replaced.

Next, the flow of the sheet will be described.

The sheet S1 loaded in the plurality of sheet supply cassettes 101 provided in the main body 130 of the image forming apparatus 100 and the sheet S2 loaded in the sheet supply apparatus 200 are selectively used. You.

When a large number of sheets are used at one time, the sheets are fed from the sheet feeding device 200.

When the sheet S2 is stacked on the sheet stacking plate 205 and the sheet tray 201 is set in the storage section, an opening / closing detecting means (not shown) is activated, and the winding shaft 208 is wound around the wire rope 209 by a driving source such as a motor. , And the sheet loading plate 205 is lifted by the take-up winch 210.

The sheet stacking plate 205 is connected to the upper limit detecting means 21.
When the position reaches the position where 5 operates, the driving source stops, and the sheet stops at the sheet supply position. At this time, if the sheet presence / absence detection means 216 is activated, the image forming apparatus 10
In synchronization with the sheet supply timing of 0, the sheet supply device 200 starts supplying the sheet.

A motor for driving separation rollers for separating sheets (not shown) according to the sheet supply timing of the image forming apparatus 100, and the separated sheets are fed to the image forming apparatus 10.
The sheet is conveyed to the nip between the feed roller 203 and the retard roller 204 by the pickup roller 202 and separated into only one sheet. The separated sheet is detected by the pre-registration sensor 217. The electromagnetic clutch mounted on the registration roller 212 stops the current after a certain period of time from when the leading end of the sheet reaches the pre-registration sensor, and the registration roller 212 stops.

The sheet is fed to the stopped registration roller 212.
And enters the nip with the pressing roller 213 to form a slight loop and remove skewing. Thereafter, the sheet is conveyed when current flows again through the electromagnetic clutch and the registration roller 212 rotates.

The sheet is conveyed into the main body 130 of the image forming apparatus via the conveying roller 214, and is conveyed to the main body registration roller 108 by the intermediate roller 106 in the main body 130 of the image forming apparatus.

When a large number of sheets are not used at one time, the sheets are fed from a sheet feeding cassette 101 in the main body 130 of the image forming apparatus 100.

The sheet S1 is picked up by the pickup roller 102.
Is fed from the sheet supply cassette 101 to the nip between the feed roller 203 and the retard roller 204 to be separated into only one sheet. The separated sheet is detected by the pre-registration sensor 105. The sheet is conveyed to the main body registration roller 108 by the intermediate roller 106.

Next, the laser unit 114 applies a laser beam to the photosensitive drum (image forming means) 112 to form a latent image on the photosensitive drum. Toner is attached to the latent image,
The latent image becomes a toner image. The registration roller 108 also rotates in accordance with the rotation of the photosensitive drum 112, and the transfer charger 113
As a result, the toner image is transferred to the sheet. The sheet is conveyed to the fixing unit 115. The toner image is fixed on the sheet by applying heat and pressure by the fixing roller 116. The sheet on which the toner image is fixed by the fixing unit 115 is moved by the flapper 117 to the main body 130.
It is selected whether the sheet is to be stacked on the stacking section 121 installed on the upper part of the sheet or the sheet is sent out to the discharge sheet stacking apparatus 300. The sheet guided to the face-down discharge roller 118 by the flapper 117 is conveyed into the discharge sheet stacking device 300 by the face-down discharge roller 118.

The sheet conveyed to the discharged sheet stacking device 300 is selected by the flapper 301 to be inverted and face-down stacked or face-up stacked as it is.

The sheet whose reversal is selected by the flapper 301 is conveyed to the reversing unit by the conveying roller 302, switched back by the reversing roller 304, sent to the discharge roller 306 via the conveying roller 305, and transferred to the stacking tray 307 b. Is discharged.

(First Embodiment) Next, a discharge sheet stacking apparatus 300 according to a first embodiment will be described with reference to FIGS.

Loading tray (tray) 3 for loading sheets
Reference numerals 07a to 307c are attached to the tray frame (elevating means) 309 at selected positions. The tray frame 309 is formed with a rack 309d that uses a pulse motor and meshes with a pinion 311a of an elevating motor (drive unit) 311 using a pulse motor. The tray frame 309 is moved up and down by an elevating motor 311 to move a tray to be used among a plurality of stacking trays to a position near a sheet discharge port (sheet discharge section) 340, and the sheets discharged from the sheet discharge port 340 by the tray. Is to be received.

When the tray to be used is changed from the loading tray 307b to the loading tray 307a or the loading tray 307c, the shutter 312 is raised by a drive source (not shown) and a link to close the sheet discharge port 340 and form a sheet abutting surface. I do. The sheet is raised and lowered together with the stacking trays 307a to 307c while sliding on the abutting surface.

The amount of sheets S3 stacked on the stacking trays 307a to 307c is determined by the distance measuring sensor 30.
8 and the stacking trays 307a to 307c
The height is controlled so that the top one of the stacked sheets comes below the discharge roller 306 by a certain distance.

In the side view of the discharged sheet stacking apparatus 300 shown in FIG. 2, a tray frame 309 has a pair of opposed side plates 309a and 309b and a stay 3 for connecting the side plates.
09c. The side plates 309a and 309b have fitting holes (mounting positions) 313 for supporting the loading trays 307a to 307c, and loading trays 307a to 307c.
A plurality of screw holes 314 for fixing c are provided in the vertical direction of the tray frame 309.

The fixing of the stacking trays 307a to 307c to the tray frame 309 is performed by projecting portions 321 and 3 projecting from the stacking tray at positions substantially opposed to the tray frames.
After engaging the holes 22 and 323 with the fitting holes 313, the screws 315
Is screwed into the screw hole 314.

The number of stacking trays fixed to the tray frame and the interval between the trays can be arbitrarily set up to the number of fitting holes 313 and screw holes 314 arranged in the tray frame. In this embodiment, three of the six pairs of fitting holes 313 are selected and three stacking trays are fixed to the tray frame 309, but the number of stacking trays is not limited.

Further, the method of fixing the stacking tray to the tray frame is not limited to screwing. For example, the configuration is not limited as long as it can be fixed easily and securely, such as a snap fit.

Next, referring to FIG. 3, which is a perspective view of the tray frame 309 and the stacking trays 307a to 307c, means for detecting attachment of the stacking trays 307a to 307c will be described.

Tact switches (attachment tray detecting means) 316a to 316f are fixed at positions substantially opposite to the six fitting holes 313 of the tray frame side plate 309a. The tact switches 316a to 316f are kept OFF when the loading trays 307a to 307c are not attached.
7a to 307c are attached to the tray frame, that is, the protrusions 321, 322, 323 of the loading tray.
When (see FIG. 2) is fitted into each fitting hole 313, it is pressed by the protruding portions 321, 322, and 323 to be turned on.

In FIG. 4, a control unit (control means) 317 for controlling the lifting and lowering of the loading tray is provided with a tact switch 316.
The lifting motor 311 is controlled based on signals from the sensors a to 306f and the distance measuring sensor 308 to move the stacking tray to a position near the sheet discharge port 340.

The control unit 317 previously stores the distance between the fitting holes 313 in correspondence with the number of drive pulses when the tray motor 309 moves the tray frame 309 up and down. If there is a tact switch that does not operate, the number of pulses between the activated tact switches is added, and the distance between the stacking trays is stored.
For example, in FIG. 3, the distance between the uppermost stacking tray 307a and the middle stacking tray 307b is determined by a fitting hole corresponding to the tact switch 316a and the tact switch 31.
6b, the number of pulses at a distance from the fitting hole corresponding to the tact switch 316b,
16c is stored in the control unit 317 in correspondence with the pulse number obtained by adding the pulse number at the distance to the fitting hole corresponding to 16c.

Therefore, the controller 317 controls the lifting motor 31
1 is pulse-controlled, and the tray frame 309 is raised and lowered so that the loading tray to be used among the plurality of loading trays can be moved to the vicinity of the sheet discharge port 340.

(Second Embodiment) A discharge sheet stacking apparatus 400 according to a second embodiment will be described with reference to FIGS.

FIG. 5 is a partial cross-sectional front view showing the configuration of a tray elevating system of the discharged sheet stacking device 400 according to the second embodiment, FIGS. 6 and 7 show the arrangement of sensors, and FIG. 8 is a control block diagram. It is. The same parts as those in the first embodiment are denoted by the same reference numerals.

The discharged sheet stacking device 400 of the second embodiment
Then, instead of the tact switches 316a to 316f for detecting the mounting positions of the stacking trays 307a to 307c, a tray detecting sensor (passing tray detecting means) 318 and a stacking limit sensor 319 are provided on the main body 441 of the discharge sheet stacking device 400. The configuration is simpler than that of the discharged sheet stacking device 300 of the first embodiment.

In FIG. 5, the tray detection sensor 318
Is a discharge roller 30 indicated by a broken line provided on the main body 441.
6 and below. Loading limit sensor 31
Reference numeral 9 denotes an upper portion near the discharge roller 306.

The tray detection sensor 318 and the stacking limit sensor 319 are normally in the OFF state, and the stacking trays 307 a to 307 c are moved to the vicinity of the sheet discharge port 340 as the tray frame 309 is moved up and down by the elevating motor (driving means) 411. The main body 441 is provided at a position where it is turned ON by the protrusions 321, 322, 323 of the stacking tray when the main body 441 moves to the position.

Further, when the tray frame 309 is lowered to the lowermost position, ie, the position shown by the solid line in FIG. 5, the tray detection sensor 318 detects that the loading tray 307 attached to the uppermost position where the loading tray can be attached. Of the tray frame 3
5 is provided on the main body 441 so as to be located below the protruding portion 323 of the stacking tray 307c when it is raised to the uppermost position, that is, the position indicated by the broken line in FIG.

The desired fitting hole 31 of the tray frame 309
After engaging the protrusions 321 to 323 of the stacking trays 307a to 307c with the stacking tray 3 and fixing the stacking tray, the discharge sheet stacking apparatus 400 is connected to the main body 130 of the image forming apparatus 100 and the image forming apparatus is not shown. When the power switch is turned on, the discharged sheet stacking apparatus 400 performs an initialization operation of the apparatus 400.

The control unit 317 raises the tray frame 309 from the lowermost position to the uppermost position in the movable range of elevation,
By counting the number of times the tray detection sensor 318 switches from OFF to ON, the discharged sheet stacking device 400
The number of loading trays attached to the storage device is stored in the memory.

Based on FIG. 6, FIG. 7, and FIG. 8, selection control of a loading tray to be used from among a plurality of loading trays attached to the tray frame 309, and the use of the loading tray to a position close to the sheet discharge port 340. The lifting control for raising and lowering will be described.

The control unit 317 raises the tray frame 309 from the lowermost position of the tray frame 309, that is, the lowermost position indicated by a solid line in FIG. 5, and counts the number of times the tray detection sensor 318 switches between OFF and ON. Then, the loading tray to be used is selected.

As shown in FIG. 6, the tray detection sensor 31
8 is switched a predetermined number of times and is in the ON state, the desired stacking tray to be used is in a state where sheets discharged from the sheet discharge port 340 can be stacked.

The height control of the stacking tray is the same as in the first embodiment. That is, the control unit 317 always moves the uppermost sheet S3 downward by a certain distance from the discharge roller 306 based on the detection information of the distance measuring sensor 308 that detects the uppermost sheet S3 stacked on the stacking tray. The loading tray used to be positioned is controlled to move up and down.

However, as shown in FIG.
As the stacking amount of sheets S3 on the stacking tray indicated by reference numeral 07b increases, the entire stacking trays 307a to 307c are
When the sheet on the stacking tray 307b is lowered until it becomes full, the stacking tray 307a disposed above the stacking tray 307b in use may block the sheet discharge port 340.

For this reason, the loading tray 3 disposed above
When the stacking limit sensor 319 is switched from OFF to ON by the projection 321 of 07a, the control unit 317 detects that the sheets on the stacking tray 307b are full and interrupts the sheet discharging operation.

The selection of the loading tray can be switched by converting the count of the tray detection sensor 318. For example, to switch from the uppermost stacking tray 307a to the third lowermost stacking tray 307c, the tray detection sensor 31
This can be performed by stopping the elevating motor 411 at three counts of eight. In this case, the height of the stacking tray 307c is adjusted by the distance measuring sensor 308.

The discharged sheet stacking device of the second embodiment can reduce the number of sensors to be used as compared with the discharged sheet stacking device of the first embodiment.

In the present embodiment, the tact switch is used for the sensor. For example, the tact switch is changed to a photo-interrupter, and the photo-interrupter is shielded from light by the projection of the stacking tray.
The positioning accuracy of 07a to 307c may be increased.

(Third Embodiment) A discharge sheet stacking apparatus 500 according to a third embodiment will be described with reference to FIGS.

FIG. 9 is a partial cross-sectional front view showing the configuration of the tray elevating system of the discharged sheet stacking apparatus 500 according to the third embodiment. FIG. 8 is a control block diagram. The same parts as those in the first embodiment are denoted by the same reference numerals.

The discharged sheet stacking device 400 of the third embodiment
The second embodiment is different from the second embodiment in that a pulse motor is used for a lifting / lowering motor (driving means) 511 and the loading limit sensor 319 is eliminated.

The control unit 317 of the discharged sheet stacking device in the third embodiment detects the number of stacking trays during the initialization operation of the discharged sheet stacking device, and measures and stores the interval between each stacking tray. It has become.

For measuring the interval between the stacking trays, a tray detection signal of a tray detection sensor (tray count detection means) 318 and a driving pulse of the lifting / lowering motor 511 are counted, and the number of pulses is used.

First, the user engages the projections 321 to 323 of the stacking trays 307a to 307c with desired fitting holes of the tray frame 309 to fix the stacking tray.

After that, the control unit 3
Reference numeral 17 denotes the number of drive pulses of the elevating motor 511 required for raising the tray frame 309 from the lowermost position of the solid line and for switching the tray detection sensor 318 from OFF to ON by the projection 321 of the stacking tray 307a. Is counted and stored, so that the position of the uppermost stacking tray 307a is stored.

Similarly, the control unit 317 controls the tray detection sensor 318 by the projection 321 of the loading tray 307a.
After the above-described OFF / ON switching operation, the loading tray 307
The lifting motor 511 required until the tray detection sensor 318 switches from OFF to ON again by the projection 322 of b.
By counting and storing the number of drive pulses of
The position of the middle stacking tray 307b is stored.

Finally, the controller 317 controls the loading tray 30
After the switching operation of the tray detection sensor 318 by the projection 322 of the tray 7b, the tray detection sensor 318 is again turned off by the projection 323 of the stacking tray 307c.
The position of the lowermost stacking tray 307c is stored by counting and storing the number of drive pulses of the elevating motor 511 required for switching from F to ON.

As described above, the control section 317 stores the number of stacking trays and the distance between the stacking trays by raising the tray frame 309 and activating the tray detection sensor 318.

Thereafter, based on the count of the stacking trays by the tray detection sensor 318 and the pulse number, the control unit 317 determines the desired stacking tray to be used in the sheet discharge port 34.
1 can be controlled to move up and down.

The control unit 317 controls the distance measurement sensor 308
In cooperation with, the stacking tray is lowered as the sheets are stacked on the stacking tray.
Since the number of pulses is counted and the height of the stacking tray is detected, it is possible to automatically detect that the sheet is full and that the sheet discharge port 340 is blocked by the upper stacking tray. Note that the distance measurement sensor 308 and the tray detection sensor 318 are connected to the main body 54 of the discharged sheet stacking device 500.
1 is provided.

Therefore, the discharged sheet stacking apparatus 500 of the third embodiment is different from the discharged sheet stacking apparatus 400 of the second embodiment.
As compared with, the number of the loading limit sensors 319 can be reduced, and the structure can be further simplified.

The discharged sheet stacking apparatus of the present invention is not limited to sheet stacking means such as a shacker or a sorter for simply stacking sheets, but also a sheet processing apparatus such as a finisher for discharging and stacking the sheets after post-processing such as stapling or punching. It can also be applied to

[0092]

According to the discharge sheet stacking apparatus of the present invention, the tray can be provided at a selected mounting position among a plurality of mounting positions of the lifting / lowering means. The number and position of trays can be changed.

Also, the control means controls the driving means,
Since the selected tray among the plurality of trays is moved up and down to a position for receiving the sheet discharged from the sheet discharge unit, the entire plurality of trays can be used effectively.

As in the discharge sheet stacking apparatus of the present invention, the position of the mounted tray can be determined by the mounted tray detecting means, and the interval between the mounted trays can be determined by the number of pulses for driving the pulse motor. Therefore, the selected tray can be accurately moved up and down to a position for receiving the sheet discharged from the sheet discharge unit.

As in the discharge sheet stacking apparatus of the present invention, when the passing tray detecting means detects the tray when the elevating means provided with the tray moves up and down, the number of the tray detecting means is determined by the above-mentioned number. The structure can be further simplified by making the number of sheets smaller than that of the discharge sheet stacking device.

As in the discharge sheet stacking apparatus of the present invention, the number of mounted trays can be determined by the tray count detecting means, and the interval between the mounted trays can be determined by the number of pulses for driving the pulse motor. Therefore, the selected tray can be accurately moved up and down to a position for receiving the sheet discharged from the sheet discharge unit.

Further, since it is detected that the selected tray is full of sheets by using the stored number of pulses and the discharge of the sheets is stopped, sheet jamming can be prevented. it can.

The image forming apparatus of the present invention is provided with the above-described discharged sheet stacking apparatus capable of effectively using a plurality of trays, so that a large amount of various types of images can be formed on sheets.

[Brief description of the drawings]

FIG. 1 is a schematic front sectional view of an image forming apparatus provided with a discharge sheet stacking apparatus of a first embodiment in a main body.

FIG. 2 is a left side view of FIG. 1, showing a main part of the discharged sheet stacking device of the first embodiment.

FIG. 3 is a perspective view of a main part of the discharged sheet stacking device of the first embodiment shown in FIG.

FIG. 4 is a control block diagram of the discharged sheet stacking device of the first embodiment.

FIG. 5 is a partially cutaway front view of a main part of a discharge sheet stacking apparatus according to a second embodiment.

FIG. 6 is an operation explanatory diagram mainly illustrating a sensor of the discharged sheet stacking device of the second embodiment.

FIG. 7 illustrates a discharge sheet stacking device according to a second embodiment.
FIG. 9 is an explanatory diagram mainly illustrating a sensor when a sheet on a stacking tray is full;

FIG. 8 is a control block diagram of a discharged sheet stacking device according to a second embodiment.

FIG. 9 is a partially cutaway front view of a main part of a discharge sheet stacking apparatus according to a third embodiment.

FIG. 10 is a control block diagram of a discharge sheet stacking device according to a third embodiment.

[Explanation of symbols]

S1 sheet S2 sheet 100 Image forming apparatus 101 Sheet supply cassette 112 Photosensitive drum (image forming means) 130 Main body of image forming apparatus 200 Sheet supply apparatus 201 Sheet tray 300, 400, 500 Discharge sheet stacking apparatus 307a Stacking tray (tray) 307b Stacking Tray (tray) 307c Loading tray (tray) 308 Distance sensor 309 Tray frame (elevating means) 309a Side plate 309b Side plate 309c Stay 309d Rack 311 Elevating motor (driving means, pulse motor) 311a Pinion 312 Shutter 313 Fitting hole (mounting position) ) 314 Screw hole 315 Screw 317 Control unit (Control unit) 316a to 316f Tact switch (Mounting tray detection unit) 318 Tray detection sensor (Passing tray detection unit, Tray) Unt detection means) 319 Stacking limit sensor 321, 322, 323 Projection 340 Sheet discharge port (sheet discharge section) 341, 441, 541 Main body of discharge sheet stacking device 411 Elevating motor (driving means) 511 Elevating motor (driving means, pulse motor)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Makoto Izumi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Takashi Kuwata 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside the Company (72) Inventor Judge Sekiya 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Yuzo Isoda 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. F term (reference) 3F050 BE01 CB04 CB08 CC01 CE03 LA02 LA05 LA07 LB03 3F054 AA01 AC02 AC03 AC05 BA04 BD02 BF07 BF22 BF24 CA16 CA33 CA40 DA01

Claims (5)

[Claims] An elevating means provided on the main body so as to be capable of elevating and lowering by a driving means; and a sheet discharging portion of the main body selectively provided at a plurality of mounting positions vertically arranged on the elevating means. A plurality of trays on which sheets discharged from the sheet stacker are stacked; and a control unit for controlling the driving unit to move a selected one of the plurality of trays up and down to a position for receiving the sheets discharged from the sheet discharge unit. And a discharge sheet stacking device, comprising: 2. A mounting tray detecting means for detecting a tray provided in the elevating means, corresponding to the plurality of mounting positions, wherein the driving means has a pulse motor; The distance between the mounting positions is stored in correspondence with the number of pulses of the pulse motor, and the position where the tray is provided is stored based on the number of pulses and the detection signal of the mounting tray detecting unit, and the pulse is stored. By controlling the rotation of the motor, among the plurality of trays,
2. The discharged sheet stacking device according to claim 1, wherein when the number of pulses corresponding to the selected tray is reached, lifting of the lifting means is stopped. 3. A passing tray detecting means for detecting the tray when the elevating means provided with the tray is moved up and down, wherein the control means moves the elevating means up and down, and The tray is detected, the number of the trays is stored, and again, the tray is detected by the passing tray detecting means, and the number of the trays is counted, and the counted number corresponding to the selected tray among the plurality of trays is obtained. 2. The discharged sheet stacking apparatus according to claim 1, wherein the lifting / lowering operation of the lifting / lowering means is stopped when the passing tray detecting means detects the tray. 4. A tray count detecting means for detecting the tray when the elevating means provided with the tray is moved up and down, wherein the driving means has a pulse motor, and the control means operates the pulse motor. Then, the tray is detected by the tray count detection means,
The number of the trays is stored, and the distance between the trays is stored in correspondence with the number of pulses of the pulse motor, and again,
The tray is detected by the tray count detection means,
2. The discharged sheet stacking apparatus according to claim 1, wherein the trays are counted, and when a count number corresponding to the selected one of the plurality of trays is reached, the lifting / lowering operation of the lifting / lowering means is stopped. 3. 5. The discharged sheet stacking apparatus according to claim 1, wherein the image forming unit forms an image on a sheet, and the sheet on which the image is formed by the image forming unit is discharged. An image forming apparatus, comprising: