JP2003327360A - Sheet transporting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet transporting device not involving such a risk that a sheet for clutch measurement processing is entrapped in sheets transported according to the user's request. <P>SOLUTION: The sheet transporting device includes a sensing means to sense existence of any sheet in each of a plurality of sheet exhaust trays for distinguishing the sheets transported for acquiring the first and the second data stored in a storing means from the sheet transported according to the user's request, whereby the sheets transported for acquiring the first and the second data stored in a storing means are exhausted to the exhaust tray from which no sheet is sensed. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying device for conveying a sheet.

[0002]

2. Description of the Related Art In a conventional electrophotographic copying apparatus, a skewed sheet is fed by abutting a sheet fed with a registration roller provided immediately in front of a photosensitive drum being stopped against a nip portion of the registration roller. It is configured to correct. In a copying machine with a long distance between the paper feed section and the photosensitive drum, in order to improve the productivity of the copying machine,
Subsequent sheets are sequentially fed without waiting for the preceding sheet to be imaged by the photosensitive drum. Therefore, a plurality of sheets are present in the transport path from the paper feed unit to the photosensitive drum.

At the timing of correcting skew of the sheet,
The sheet is in a substantially stopped state at the position of the registration roller, so that the succeeding sheet cannot catch up with this sheet.
Subsequent sheets are also suspended depending on this. Then, the roller immediately before the photosensitive drum and the roller from the paper feeding unit to the photosensitive drum are simultaneously driven in synchronization with the rotation timing of the image on the photosensitive drum, and the feeding of a plurality of sheets in the conveying path is restarted.

[0004]

It is desired to further improve the productivity of such a conventional copying apparatus, and for that purpose, it is necessary to further reduce the sheet interval. However, if the sheet interval is made shorter than in the conventional case, the shift of the sheet stop position, which has not affected the conventional case, becomes a problem. The roller for feeding the sheet is driven by a DC motor via a clutch, and the clutch is released when the sheet is temporarily stopped. When the clutch is released, the roller stops due to friction of the roller bearing. Since the roller is stopped by the friction of the bearing, the roller slightly rotates from the release of the clutch to the stop of the roller, and the subsequent sheet sandwiched by such a roller is abutted against the registration roller. It approaches the seat. In this state, since the feeding of all the sheets temporarily stopped in the conveyance path is restarted at the same time, the trailing edge of the preceding sheet and the leading edge of the succeeding sheet are fed in a state where the distance between them is extremely close, Abnormality may occur in sheet conveyance control.

In order to effectively carry out the above-described sheet carrying control, there is a case where the sheet is actually carried only for correction and adjustment, and feedback is performed to carry out the carrying control. At that time, there is a possibility that a sheet used only for correction or adjustment may be mixed with the sheet output by the user request.

[0006]

In order to solve the above-mentioned problems, the present invention drives first, second and third rollers for conveying a sheet and the first, second and third rollers. Of the first, second and third clutches for transmitting the driving force of the driving means to the first, second and third rollers, and the first, second and third clutches. Control means for controlling coupling and disengagement, and first data relating to a stop characteristic of the sheet when the first and second clutches are disengaged when the first and second rollers are sandwiching the sheet. And storage means for storing second data relating to a stop characteristic of the sheet when the second and third clutches are released while the second and third rollers are sandwiching the sheet, and a plurality of storage means. Sheet conveyance having a paper discharge path and a plurality of paper discharge trays In the above arrangement, the control means controls the connection timing of the first, second and third clutches based on either the first or second data stored in the storage means, and stores them in the storage means. In order to distinguish the conveyed sheet for obtaining the obtained first and second data from the conveyed sheet from the user request, the sheet is detected by each of the plurality of discharge trays by the detecting unit. For the output tray that was not detected,
It is characterized in that the conveyed sheet is discharged to obtain the first and second data stored in the storage means.

Further, when sheets are detected in all of the plurality of discharge trays by the detecting means, the storage is carried out in a conveyance path which does not affect obtaining the first and second data stored in the storage means. It is characterized in that the conveyed sheet is discharged to obtain the first and second data stored in the means.

Further, the image forming means, the first, second and third rollers for conveying the sheet, the driving means for driving the first, second and third rollers, and the driving force of the driving means. To the first, second and third rollers,
Second and third clutches, control means for controlling connection and disengagement of the first, second and third clutches, and the first and second rollers when the sheet is nipped. 1st data regarding the stop characteristic of the sheet when the 1st and 2nd clutches are released, and when the 2nd and 3rd rollers hold the sheet, the 2nd and 3rd clutches are released. In a sheet conveying device having storage means for storing second data relating to the stopping characteristic of the sheet at the time of the above, the control means is based on either the first data or the second data stored in the storage means. To control the connection timings of the first, second and third clutches and distinguish the sheet conveyed to obtain the first and second data stored in the storage means from the sheet conveyed from the user request. , It is characterized in that printed images showing that by the image forming apparatus is a sheet that is transported in order to obtain first and second data stored in said storage means to the seat.

[0009]

1 shows an image forming apparatus according to an embodiment of the present invention. The image forming apparatus of this embodiment includes a printer 10
0, optional paper feed deck D200, operation unit 300, scanner 310, document feeder 320, sheet folding machine 33
0 and a finisher 340. Printer 100
Forms an original image read by the scanner 310 by an electrophotographic method or an image received via a network on a sheet. The document feeder 320 automatically feeds the document to the reading position of the scanner 310. The option paper feed deck D200 has a large-capacity sheet stacking unit, and is attached to the printer 100 as required by the user. The operation unit 300 inputs the settings of the image forming apparatus and displays the state of the image forming apparatus. The sheet folding machine 330 Z-folds an A3 size sheet. When folding is not set by the operation unit 300, the sheet is sent to the finisher 340 on the downstream side without folding the sheet. The finisher 340 is a sheet discharge unit having a plurality of sheet discharge trays, and is also a sheet finishing unit that performs sheet binding processing and the like. The finisher 340 discharges the sheet conveyed from the upstream side to the discharge tray 341 or the discharge tray 342.

In the printer 100, the laser emitting section 1
Reference numeral 50 emits laser light according to the image from the scanner 310 or the image received via the network. This laser light is applied to the photosensitive drum 152, and a latent image is formed on the photosensitive drum 152. The photosensitive drum 152 is developed with toner, and the toner image is transferred to the fed sheet. The toner transferred to the sheet is fixed on the sheet by the fixing roller 154. Fixing roller 15
The sheet that has passed 4 is sent to the sheet folding machine 330 on the downstream side via the discharge path 158, or the sheet is turned upside down via the double-sided path 156 and sent again to the photosensitive drum 152.

The printer 100 includes a paper feed cassette D108,
Sheets can be fed from D109, the paper feed decks D110 and D111, and the manual paper feed section 160, and further, the sheets can be fed from the optional paper feed deck D200.

FIG. 2 shows the structure of sheet conveyance in the printer 100. The sheets stacked in the sheet feeding cassette D108 are picked up by the roller R108, separated from the sheets other than the uppermost sheet, and sent out. This sheet includes rollers R100, R101, R102, R103, R1.
14, R115 conveys the toner to the photosensitive drum 152.
Similarly, the sheets sent from the paper feed cassette D109 by the roller R109 are the rollers R101, R102, R1.
It is conveyed to the photosensitive drum 152 by 03, R114, and R115. Also, from the paper feed deck D110 to the roller R11
The sheet sent by 0 is rollers R103, R11
4, the sheet is conveyed to the photosensitive drum 152 by R115. Further, the sheets sent by the roller R111 from the paper feed deck D111 are the rollers R105, R106, R10.
The sheet is conveyed to the photosensitive drum 152 by 7, R114, and R115. Further, from the manual paper feeding unit 160 to the roller R112.
The sheets sent out by the rollers are rollers R113 and R115.
Are conveyed to the photosensitive drum 152. Further, the sheet sent from the optional paper feed deck D200 by the roller R202 is conveyed to the photosensitive drum 152 by the rollers R201, R114, and R115.

Sheets fed from the sheet feeding cassettes D108 and D109, the sheet feeding decks D110 and D111, the manual sheet feeding section 160, the optional sheet feeding deck D200, and the double-sided path 156 may skew. Therefore, the skew of the sheet is corrected by abutting the sheet against the registration roller R115 with the registration roller R115 stopped. Further, in order to improve the productivity of the image forming apparatus, the subsequent sheets are sequentially fed without waiting for the image formation of the preceding sheet by the photosensitive drum 152. Therefore, there are a plurality of sheets in the transport path from the paper feed unit to the photosensitive drum 152. Registration roller R1
Since the sheet abutted against 15 is in a substantially stopped state, so that the succeeding sheet cannot catch up with this sheet,
Subsequent sheets are also suspended depending on this.

Rollers R100-R103, R105-R
115, R201, and R202 are clutch C10, respectively.
0-C103, C105-C115, C201, C20
It is driven by the motor 120 via 2. Motor 12
0 is a DC motor. Motor 1 by connecting the clutch
The driving force of 20 is transmitted to the roller, and the driving force of the motor 120 is not transmitted to the roller by releasing the clutch.

The rollers R114 and R115 are provided with electromagnetic brakes B114 and B115, respectively.
Clutch C114 and C1 corresponding to each roller
By turning on the electromagnetic brakes B114 and B115 together with the release of 15, the rollers R114 and R115 can be stopped instantaneously.

Rollers R100 to R103, R105 to R
No electromagnetic brake is provided on 113, R201, and R202, and the roller is stopped only by releasing the clutch. Since no electromagnetic brake is provided on each of these rollers, the cost of the image forming apparatus can be reduced. When the clutch is released, the roller rotation is stopped due to the friction of the roller bearing and the friction of the contact portion of the roller pair. The friction of the contact portion of the roller pair differs depending on the material of the rollers. The roller rotation amount from the clutch release to the roller stop, that is, the sheet advance amount from the sheet stop depends on various factors such as the frictional force of the roller bearing, the mechanical structure of the roller, the material of the roller, and the individual difference of the roller. When these sheets are sandwiched by a plurality of types of rollers, they affect each other, and the sheet advance amount from the clutch release to the sheet stop varies.

Table 1 shows the bearing type of each roller, the material of the roller, the mechanical structure for driving the roller, and the presence or absence of the electromagnetic brake. Rollers R100, R101, R105, R106,
R113 and R201 are rubber rollers held by sintered bearings, and no electromagnetic brake is provided. Laura R
102 and R103 are rubber rollers held by bearings, and no electromagnetic brake is provided. The roller R107 is a sponge roller held by a bearing bearing and is not provided with an electromagnetic brake. The roller R107 conveys the sheet and removes the curl. Rollers R108, R109, R110, R111,
R112 and R202 are separation rollers made of rubber rollers, and have a mechanical structure in which one of the roller pairs rotates in the feeding direction and the other rotates in the direction opposite to the feeding direction for sheet separation.

The rollers R114 and R115 are rubber rollers held by sintered bearings, and are electromagnetic brakes B114 and B.
115 is provided. The registration roller R115 has to be stationary after the preceding sheet is fed and when the succeeding sheet fed at a small sheet interval arrives, the rotation of the roller is instantaneously performed after the trailing edge of the sheet passes through the roller. There is an electromagnetic brake that can be stopped.
Further, the roller R114 is a sheet for registering the roller R11
An electromagnetic brake is provided to stop the roller after driving the roller for a predetermined time after the roller has been abutted against the sheet No. 5 and a predetermined amount of the sheet has been fed.

[0019]

[Table 1]

With respect to the roller not provided with the electromagnetic brake, the rotation of the roller is stopped by releasing the clutch. However, it takes a long time from the clutch release to the roller rotation stop because it is the rubber roller held by the bearing. In addition, a sponge roller held by a bearing bearing, a rubber roller held by a sintered bearing, and a separation roller having a separation mechanism that stops in the shortest time.

Rollers R100 to R103, R105 to R
Sensors S100 to S115, S201, and S202 are provided near 115, R201, and R202, respectively. Further, the sensor S11 is provided on the upstream side of the photosensitive drum 152.
5 and S114 are provided. The sensor S115 is for timing to stop the sheet when the sheet is conveyed by a predetermined amount after the leading edge of the sheet hits the nip portion of the registration roller R115. The sensor S114 is for timing the laser light emitting unit 150 to form a latent image on the photosensitive drum 152.

Sensors S102, S106, S107, S
104, S114, S115, S112, S113
As shown in FIG. 8, the flag type sensor is composed of a movable flag 170 and a light emitting portion and a light receiving portion 172 provided in the movable range of the flag. When the conveyed sheet passes the sensor, the flag 170 ( The movable member) is tilted. When the flag 170 blocks the optical paths of the light emitting unit and the light receiving unit 172, that is, when the flag 170 is not tilted by the sheet (when the flag 170 is at the first position), it is determined that there is no sheet. When the flag 170 does not block the optical paths of the light emitting unit and the light receiving unit 172, that is, when the flag 170 is not tilted to the sheet (when the flag 170 is at the second position), it is determined that there is a sheet. In this way, the flag 170 indicates that the light emitting unit and the light receiving unit 17
The leading edge of the sheet and the presence / absence of the sheet are detected by detecting whether or not the optical path between the two is blocked. The flag 170 is urged by a spring to be in the state of a solid line, and when the rear end of the sheet comes off, the flag 170 returns so as to block the optical paths of the light emitting portion and the light receiving portion 172.
Since 70 does not return instantly and there is a time lag in return, it is difficult to accurately detect the trailing edge of the sheet. As described above, since the flag type sensor is not suitable for accurately detecting the trailing edge of the sheet, the rollers R108 and R1 that detect the trailing edge of the preceding sheet at the time of sheet feeding and produce an accurate sheet interval.
09, sensors S108 and S1 near R110 and R111
00, S109, S101, S110, S102, S1
11, an optical sensor is used for S105.

Sensors S108, S100, S109, S
101, S110, S102, S111, S105
As shown in FIG. 9, the optical sensor is composed of a light emitting unit 174 and a light receiving unit 176, and whether or not the sheet interrupts the optical path between the light emitting unit 174 and the light receiving unit 176 when the conveyed sheet passes through the sensor. By detecting whether or not, the leading edge, the trailing edge of the sheet, and the presence or absence of the sheet are detected.

The photosensitive drum 152 is driven by the motor 128.
The fixing roller 154 is driven by the motor 130. The sheet sent to the double-sided path 156 is conveyed by the rollers 138, 136, 134 and 132.
The roller 138 is driven by the motor 126 so that the rollers 136, 1
34 is a motor 124, and roller 132 is a motor 12.
Driven by two. The motors 126, 124, 122 are stepping motors. In the double-sided pass, the motor must be rotated in the forward and reverse directions to switch back the sheet, and when the sheet is received from the upstream side in the double-sided pass, it rotates at the speed matched with the fixing roller, and then the sheet interval is reduced. Since it is necessary to rotate at a high speed and stop the rotation when the sheet comes to a predetermined position, a stepping motor that can easily and accurately control the speed is adopted.

FIG. 3 is a block diagram of clutch control. The outputs of the sensors S100 to S115, S201, and S202 are input to the CPU 180. The CPU 180 controls driving of the motor 120 via the amplifier 186. Figure 3
Although not shown in FIG.
It also controls the drive of 130, 122, 124, and 126. Further, the CPU 180 uses the clutches C100 to C10.
3, control connection and release of C105 to C115, C201, and C202. The setting entered on the operation unit 300 is C
Input to the PU 180, the CPU 180 causes the operation unit 300 to display a predetermined operation screen. The control program to be executed by the CPU 180 is RO readable by the CPU 180.
It is stored in M182. The control program to be described later is also stored in the ROM 182. CPU18
The data necessary for 0 to control is written in the battery-backed RAM 184. The RAM 184 is also used for data measured for correction control described later.
Written in. EEPROM instead of RAM184
It may be a non-volatile memory such as.

Next, the characteristics of the roller when the roller is driven via the clutch and the clutch is connected after the clutch is released will be described with reference to FIGS. 4 and 5. FIG. 4 shows an example of a configuration for driving the roller via a clutch. 4 (1) to 4 (3) show how the sheet SH is conveyed, and FIGS. 4 (4) to 4 (6) are timing charts of the sensor SA, the clutch CA, and the sensor SB, respectively. The roller RA is driven by the motor M via the clutch CA. A roller RB is provided on the downstream side of the roller RA. Sensors SA and SB are provided on the upstream sides of the rollers RA and RB, respectively. Laura R
A does not have an electromagnetic brake.

In FIG. 5, while the sheet SH is being conveyed by the roller RA, the clutch CA is released and the sheet SH is temporarily stopped, and then the clutch CA is connected to the sheet S.
Movement of the sheet SH when H is conveyed again (roller RA
Characteristics). The vertical axis represents the distance of the sheet SH, and the horizontal axis represents time. SH0 instantaneously stops the sheet SH at time t4, and at time t5, the sheet SH instantaneously indicates the movement of the virtual sheet SH conveyed at a predetermined speed V1, and SH0 ′ indicates the movement of the actual sheet SH.

When the roller RA is conveying the sheet SH conveyed from the upstream side, at time t4 for temporarily stopping the sheet SH, the roller RA is stopped by releasing the clutch CA. Next, at time t5 when the conveyance of the sheet SH is restarted, the roller RA is driven by connecting the clutch CA. Clutch C
Since the roller RA is stopped only by releasing A, as shown in FIG.
SH0 ', the amount of advance X from the virtual stop position
The sheet SH stops at the position advanced by one. As described above, the amount of advance X1 depends on the type of roller bearing, the material of the roller,
It depends on the mechanical structure of the roller drive and the individual difference of the roller. In addition, since it takes time to completely connect the clutch CA, there is a delay in the rising of the conveyance of the sheet SH.
The amount of advance of the sheet SH with respect to the position SH0 of the virtual sheet SH is reduced to X2.

Generally, the sheet advance amount from the clutch release to the roller stop is larger than the sheet delay amount at the time of clutch engagement. Therefore, when the clutch CA is released and then the clutch CA is engaged, a virtual The seat position is advanced by X2 from the seat position. As will be described later, the clutch engagement timing is advanced to the amount X2, that is, the time ΔT.
By delaying by A, the correction is performed so that the virtual sheet position is obtained.

The time ΔTA is from the time t1 when the leading edge of the sheet SH passes the sensor SA to the time t2 when the leading edge of the sheet SH passes the sensor SB.
The actual time TA 'until the clutch CA is released is zero and the seat delay amount is zero when the clutch CA is engaged. From the time t1 when passing the sensor SA to the time t3 when passing the sensor SB) to time T
It can be obtained by subtracting A '. When the sheet SH is conveyed at the speed V1 over the distance X1 from the sensor SA to the sensor SB, the virtual time TA is the sensor SA-S.
It is equal to the movement time X1 / V1 of the sheet SH between B and the suspension time TB. Therefore, ΔTA can be calculated by the following equation. The CPU 180 calculates ΔTA, and the CPU 180 stores ΔTA in the battery-backed RAM 184.

ΔTA = TA−TA ′ = (X1 / V1 + TB) −TA ′ = X1 / V1− (TA′−TB) FIG. 6 shows the above-mentioned ΔTA when continuously feeding sheets from the paper feed cassette D108. It is a figure which shows the movement of the front-end | tip of a sheet | seat, when minute correction is not performed. Registration roller R1
Sheets SH1, SH2, SH3 with 15 stopped
The rollers R100, R101, R102, R103, R
Delivered by 114. Sensors S108 and S100 are used so that the distance between the leading edge of each preceding sheet and the trailing sheet is D1, that is, the distance between the trailing edge of the preceding sheet and the trailing sheet is D3 as shown in FIG. 7 (1). The clutch C108 is connected according to the detection of the trailing edge of the preceding sheet. At timing t11 when the leading edge of the sheet SH1 is fed to the roller 115, the rollers R114 and R10 are fed.
3, R102, R101 and R100 are stopped. The roller R114 is stopped by the release of the clutch C114 and the electromagnetic brake B114, and the rollers R103, R102,
R101 and R100 are clutches C103 and C1, respectively.
02, C101, C100 are stopped only by releasing. Since the sheet SH2 advances when the roller R102 is stopped, the distance from the leading edge of the sheet SH1 to the leading edge of the sheet SH2 is D2, which is shorter than D1. Next, the sheet SH1 is fed by the registration rollers R115 and R114 at a predetermined timing t12 when image formation is performed, and at the same time, SH2 and SH3 are also fed to the rollers R114, R103, and R10.
2. Transported by R101 and R100. Therefore, the sheet SH2 is conveyed with the distance between the leading edge of the sheet SH1 and the leading edge of the sheet SH2 being D2.

FIG. 7 shows the sheet SH1 from the front end thereof.
2 to the front end of the sheet SH1 and the rear end of the sheet SH1 to the sheet S
It is a figure which shows the relationship of the distance to the front-end | tip of H2. Figure 7
As shown in (1), from the leading edge of the sheet SH1 to the sheet S
When the distance to the leading edge of H2 is D1, the distance from the trailing edge of the sheet SH1 to the leading edge of the sheet SH2 is D3. The distance D3 is determined by the flag position of the flag sensor (such as the sensor S104) between when the trailing edge of the sheet SH1 passes and when the leading edge of the sheet SH2 reaches the flag position in the sheet state (second This is an interval corresponding to the time when it is possible to return from the flag position (1) to the flag position (first position) in the no-seat state. As shown in FIG. 7 (2), the sheet S
When the distance from the leading edge of H1 to the leading edge of sheet SH2 is D2, the distance from the trailing edge of sheet SH1 to the leading edge of sheet SH2 is D4, which is shorter than D3. The distance from the rear end of the sheet SH1 to the front end of the sheet SH2 is
The rear end of the sensor passes the sensor S104 and then the sensor S104
Flag 17 until the leading edge of sheet SH2 reaches
If 0 is not a sufficient distance to return to the flag position in the no-sheet state, the detection result of the sensor S104 continuously indicates that there is a sheet from the trailing edge of the sheet SH1 to the leading edge of the sheet SH2. Even if it does not exist, it will be falsely detected as a jam.

Further, from the rear end of the sheet SH1 to the sheet SH
The distance from the leading edge of the sheet SH1 to the registration roller R115 after the trailing edge of the sheet SH1 passes the registration roller R115.
If the leading edge of the sheet SH2 reaches the registration roller R115 before the sheet is completely stopped, not only skew feeding of the sheet SH2 cannot be corrected, but also
Since the front end position of the sheet SH2 is deviated during standby,
There is a problem that the position of the image formed on the sheet is displaced.

FIG. 10 is a diagram showing the movement of the leading end of the sheet when the above-described correction of ΔTA is performed when the sheet is continuously fed from the sheet feeding cassette D108. Up to the timing t12, it is the same as in FIG. Paper feed cassette D108
With respect to the feeding interval of the sheet from, the sheets are separated and fed so that the distance from the trailing edge of the preceding sheet to the leading edge of the succeeding sheet is D1. This distance D1 is a distance that does not cause at least the above-mentioned erroneous detection of the jammed jam and displacement of the image, and is a distance that is shortened as compared with the conventional one so that productivity can be improved.

The sheet SH1 is fed by the registration rollers R115 and R114 at a predetermined timing t12 for image formation. SH2 after ΔTA from timing t12
Are conveyed by rollers R114, R103, R102, and R101. When the amount of advance of the sheet SH3 is the same as that of the sheet SH2, the conveyance of the sheet SH3 is started at the same time as the sheet SH2. The sheet SH2 is conveyed with the distance between the leading edge of the sheet SH1 and the leading edge of the sheet SH2 being D1 '.
The distance between the leading edge of the sheet SH1 and the leading edge of the sheet SH2 is Δ
Since it is corrected by TA, it becomes D1 '. D1 'is D1
Although the distance is shortened by the connection delay of the clutch C115, the distance of the clutch connection delay is smaller than the seat advance amount when the upstream side clutch is released. This distance D1 'is at least a distance at which the above-described erroneous detection of the jammed jam and displacement of the image do not occur.

Therefore, the rear end of the sheet SH1 and the sheet SH
The distance at the tip of 2 is corrected by the sensor S104 to the extent that it is not erroneously detected as a stay jam, and erroneous detection of stay jam can be prevented. The distance between the trailing edge of the sheet SH1 and the leading edge of the sheet SH2 is such that the trailing edge of the sheet SH1 is the registration roller R.
After the registration roller R115 is stopped after exiting 115, the leading edge of the sheet SH2 is corrected to a distance that reaches the registration roller R115, and the occurrence of image misalignment can be prevented.

These controls are performed by the CPU 180, which is a battery-backed RA.
ΔTA is read from M184 and the above-mentioned correction control is performed. Although it has been explained that the measured and calculated ΔTA is stored in the RAM 184 and is read out and subjected to correction control.
Not limited to this, ΔTA obtained in advance at the design stage is
The same effect can be obtained even if it is stored in the OM 182 and is read out from the ROM 182 for correction control.

FIG. 11 and Table 2 show combinations of rollers that sandwich an A4 size sheet or a letter size sheet when the sheet feeding is temporarily stopped in the clutch measurement mode, that is, a measurement area in the clutch measurement mode. ΔT in Table 2
Information excluding A (i) is stored in the ROM 182.
X1 (i) is the distance between the sensor SA (i) and the sensor SB (i). Regarding ΔTA (i), the RAM 1 is associated with the measurement area number in the clutch measurement mode described later.
It is stored in 84.

[0039]

[Table 2]

12 to 15 are flowcharts of the clutch measurement mode. A program for executing this flowchart is stored in the ROM 182, and the CPU 18
It is read by 0 and executed. The clutch adjustment value measurement screen (FIG. 22) in the service mode is displayed on the operation unit 300, and the clutch measurement mode is executed in response to the touch of the start key. When starting the clutch measurement mode, the CPU 180 causes the motor 120,
Turn on 128, 130 and other motors.

First, based on the detection result of the sheet presence / absence sensor provided in the paper feeding cassette D108, the paper feeding cassette D
It is determined whether there is a sheet in 108 (S400), and if there is no sheet, a warning is displayed on the operation unit 300 to set an A4 or letter size sheet in the sheet feeding cassette D108 (S402). If there is a sheet in the sheet feeding cassette D108, it is determined whether the sheet is A4 size or letter size based on the detection result of the sheet size sensor (S).
404). If the size is neither A4 nor letter size, the process proceeds to step S402.

After it is determined that the size is A4 or letter size in step S404, the paper discharge tray 341 of the finisher 340.
It is confirmed whether there is a sheet in (S406). When it is determined that there is a sheet in step S406, it is confirmed whether or not there is a sheet in the discharge tray 342 (S
408). When it is determined in step S408 that there is a sheet, it is confirmed whether there is a sheet in the double-sided path 156 (S410). When it is determined that there is a sheet in step S410, a warning is displayed on the operation unit 300 to remove the sheet of the double-sided path 156 (S412).

If it is confirmed in step S406 that there is no sheet in the paper discharge tray 341, the paper discharge tray 34
1 is determined as the discharge destination of the sheet used for the clutch measurement process (S414).

If it is confirmed in step S408 that there is no sheet in the paper discharge tray 342, the paper discharge tray 34
2 is determined as the discharge destination of the sheet used for the clutch measurement process (S416).

When it is confirmed that the sheet is not on the double-sided path 156 in step S410, the double-sided path 156 is determined as the discharge destination of the sheet used for the clutch measuring process (S418).

Next, 0 is set to the variable i (S42)
0). Then, the clutches C114 and C115 are connected (S422), and one sheet is fed from the paper feed cassette D108 (S424). The pickup roller of the roller R108 is driven by a solenoid, and when this solenoid is off, the pickup roller is the pickup cassette D10.
It is in a state of landing on the seat in No. 8. Paper feed cassette D1
In order to feed the sheet from 08, the clutch C108 is connected to the pickup roller and the roller R1.
08 is driven. When the sensor S108 is turned on, the solenoid of the pickup roller is turned on to separate the pickup roller from the sheet in the sheet feeding cassette D108.

Next, when the sensor S100 is turned on (S
426), and a clutch measurement process described later is executed (S4
28). This clutch measurement process is repeated until the sensor S104 is turned on (S430). That is, one sheet measures a plurality of areas. That is, the conveyance of the sheet is stopped between the first sensor and the second sensor, the conveyance of the sheet is restarted after the lapse of a predetermined time, and from the time when the first sensor detects the edge of the sheet. Second
Measures the time until the sensor detects the edge of the sheet, and temporarily stops the sheet between the first sensor and the second sensor and stops the sheet between the second sensor and the third sensor. ,
After the lapse of a predetermined time, the conveyance of the sheet is restarted, and when the second sensor detects the edge of the sheet,
Measures the time until the sensor detects the edge of the sheet.

Next, based on the detection result of the sheet presence sensor provided in the paper feed deck D111, the paper feed deck D11 is detected.
It is determined whether there is a sheet in 1 (S432), and if there is no sheet, an A4 or letter size sheet is fed to the paper feed deck D.
A warning is displayed on the operation unit 300 to set it to 111 (S434). If there is a sheet in the paper feed deck D111, it is determined whether the sheet is A4 size or letter size based on the detection result of the sheet size sensor (S43).
6). If the size is neither A4 nor letter size, the process proceeds to step S434.

When it is determined in step S436 that the size is A4 or letter size, one sheet is fed from the paper feed deck D111 (S438). The pickup roller of the roller R111 is driven by a solenoid, and when the solenoid is off, the pickup roller is the pickup roller D1.
It is in a state of landing on the seat in 11. Paper feed deck D1
In order to feed the sheet from 11, the pickup roller and the roller R1 are connected by connecting the clutch C111.
11 is driven. When the sensor S111 is turned on, the solenoid of the pickup roller is turned on to separate the pickup roller from the sheet in the paper feed deck D111.

Next, when the sensor S105 is turned on (S
440), and the clutch measurement process is executed (S442).
This clutch measurement process is repeated until the sensor S107 is turned on (S444).

In the image forming apparatus of this embodiment, the roller R10 is used.
Since a sensor is not provided between 6 and R107, both the area 6 and the area 7 must be measured by the sensors S106 and S107. Therefore, the sheet used for the area 6 measurement is ejected, and another sheet is used. The sheet is newly fed to measure the area 7 by the sensors S106 and S10.
Must be done by 7.

Then, the sheet feeding deck D111 again returns to A4.
Or, send letter size sheets. Paper feed deck D
It is determined whether there is a sheet in the sheet feeding deck D111 based on the detection result of the sheet presence / absence sensor provided in 111 (S4
46), if there is no sheet, set the A4 or letter size sheet on the paper feed deck D111 to the operation unit 3
A warning is displayed on 00 (S448). Paper feed deck D111
If there is a sheet in the sheet, it is determined whether the sheet is A4 size or letter size based on the detection result of the sheet size sensor (S450). When the size is neither A4 nor letter size, the process proceeds to step S448.

If it is determined in step S448 that the size is A4 or letter size, the sheet feeding deck D1 is used as in step S438.
One sheet is fed from 11 (S452).

Next, when the sensor S106 is turned on (S
454), and clutch measurement processing is executed (S456).
Thus, in the clutch measurement mode, the paper feed deck D111
Will measure two sheets in total.

Next, based on the detection result of the sheet presence / absence sensor provided in the paper feed deck D200, the paper feed deck D20
It is determined whether or not there is a sheet at 0 (S458), and if there is no sheet, an A4 or letter size sheet is fed to the paper feed deck D.
A warning is displayed on the operation unit 300 to set it to 200 (S460). If there is a sheet in the sheet feeding deck D200, it is determined whether the sheet is A4 size or letter size based on the detection result of the sheet size sensor (S46).
2). If the size is neither A4 nor letter size, the process proceeds to step S460.

When it is determined in step S462 that the size is A4 or letter size, one sheet is fed from the paper feed deck D201 (S464). The pickup roller of the roller R201 is driven by a solenoid, and when the solenoid is off, the pickup roller is the pickup deck D2.
It is in a state of landing on the seat in 01. Paper feed deck D2
To feed the sheet from 01, the clutch C201 is connected to the pickup roller and the roller R2.
01 is driven. When the sensor S201 is turned on, the solenoid of the pickup roller is turned on to separate the pickup roller from the sheet in the paper feed deck D201.

Next, when the sensor S201 is turned on (S
470) and the clutch measurement process is executed (S472).
After the clutch measurement process, when it is detected by the sensor provided in the paper discharge unit that all the sheets have been discharged to the discharge destination determined in step S414, step S416, or step S418, the process ends (S474).

Further, in the above description, the sheet used in the clutch measurement process and the sheet discharged by the user's request are distinguished by the discharge destination. However, the photosensitive drum 152 which is an image forming means inside the sheet conveying device and the fixing are fixed. The roller 154 may print an image indicating that the sheet is used in the clutch measurement process.

FIG. 16 is a flowchart of the clutch measuring process called in the above-mentioned clutch measuring mode. A program for executing this flowchart is stored in the ROM 182, read by the CPU 180, and executed. The CPU 180 has a built-in free-run counter for managing the current time, which is automatically counted up during the execution of the program, and the CPU 180 can manage the current time by this counter.

First, 1 is added to the variable i (S500), and R
Referring to the rollers in the area i shown in Table 2 stored in the OM 182, the clutches corresponding to these are connected (S501), and the current time is set to t1 (i) (S).
502). Then, T of Table 2 stored in the ROM 182
Referring to C (i), wait TC (i) time (S50
4), the clutches of the rollers in the areas i and (i1) are released (S506). Since the area 0 does not exist when the variable i is 1, the roller clutch in the area 1 is released. Then, after waiting TB time (S508), the clutch of the roller in the area i is connected (S510). Referring to SB (i) in Table 2, the output of the sensor SB (i) is monitored, and when the sensor SB (i) is turned on (S
512), t2 (i) is set to the current time (S51)
4). Then, t2 (i) -t1 (i) is calculated, and TA '
(I) is set (S516), X1 (i) / V1- (TA '(i) -TB) is obtained by referring to X1 (i) in Table 2, and corresponds to the area number i as ΔTA (i). RA
It is stored in M184 (S518), and the process returns to the clutch measurement mode shown in FIGS.

As described above, the measurement of each area is performed. It should be noted that TC1 has a time sufficient for the leading edge of the sheet to pass through the first roller located downstream of the sensor SA (i) and the second roller located downstream of the sensor SA (i) and the sensor SB ( i) is the time when the leading edge of the sheet does not reach, and TC2 is a time sufficient for the leading edge of the sheet to pass through the roller located second downstream of the sensor SA (i) and the sheet is detected by the sensor SB (i). It is the time when the tip of does not reach.

Further, as shown in FIG. 22, the operation unit 300 displays whether or not the measurement is being performed or the measurement is completed. Further, as shown in FIG. 23, ΔTA (i) may be displayed on the operation unit 300.

FIG. 17 is a sheet feeding control for feeding a sheet from one of the sheet feeding decks D110, D111, D200 and the sheet feeding cassettes D108, D109 to the photosensitive drum 152 when the image forming apparatus forms an image. It is a flowchart of. A program for executing this flowchart is stored in the ROM 182, read by the CPU 180, and executed.

First, since the skew feeding of the sheet is corrected by the registration roller R115, the clutch C115 is released and the brake B115 is turned on to stop the registration roller R115 (S600). And the operation unit 3
The sheets are continuously fed from the sheet feeding deck or the sheet feeding cassette designated by 00 so that the distance between the trailing edge of the preceding sheet and the leading edge of the succeeding sheet becomes D3 (S60).
2). In the sheet feeding control in step S602, the transport amount of each sheet is managed based on the detection result of the sensor and the transport time of the sheet, and the leading edge position information (from the registration roller R115) that always indicates the latest leading edge position of each sheet. Distance) together with the size information of each sheet in the RAM 184
To memorize. It is determined whether the sensor S115 is turned on, that is, whether the leading edge of the most preceding sheet reaches the sensor S115 (S604), and if not turned on, step S602 is continued. When it is turned on in step S604, a TL time is waited (S606), and a sheet feeding temporary stop process described later is performed (S608). In the sheet feeding temporary stop process, the most preceding sheet is temporarily stopped, and all the succeeding sheets are temporarily stopped so that the succeeding sheet does not collide with the preceding sheet. TL is the registration roller R after the leading edge of the sheet passes the sensor S115.
It is a time for causing the sheet to be conveyed by a predetermined amount after the sheet hits the nip portion of 115.

Then, at a timing when the image formed on the photosensitive drum 152 and the sheet coincide with each other (S610), a sheet feeding restart process described later is performed (S).
612). It is determined whether or not this sheet is the final sheet to be image-formed (S614), and if it is not the final sheet, the process returns to step S602. If it is the final sheet, the process ends when the final sheet is ejected by the ejection roller (S61).
6).

FIG. 18 is a flowchart of the sheet feeding temporary stop process called by the above-described sheet feeding control.
The program for executing this flowchart is RO
It is stored in the M182, read out by the CPU 180, and executed. The sheet feeding temporary stop process is performed according to the clutch control order shown in Table 3 stored in the ROM 182. The clutch control order is from the order closer to the registration roller R115, that is, from the downstream side to the upstream side. First, the clutch C114 is released (S70
0), the brake B114 is turned on (S702). Then, the variable i is set to 1 (S704), and the ROM 182 is set.
The clutch C (i) shown in Table 3 stored in the table is released (S706).

[0067]

[Table 3]

Then, the current time is set in t (i) (S708), and 1 is added to the variable i (S710). It is determined whether the variable i has become 14, and if it has not become 14, the process returns to step S706. When the variable i becomes 14, the process returns to the sheet feeding control of FIG.

FIG. 19 is a flow chart of the sheet feeding restart processing called by the above-described sheet feeding control. The program for executing this flowchart is ROM1
It is stored in 82 and is read and executed by the CPU 180. In the sheet feeding restart process, first, the brake B11
5 and B114 are turned off (S800, S802), and the clutches C115, C114 are connected (S804, S80).
6). Next, the variable i is set to 1 (S808) and the total waiting time variable TWT is set to 0 (S81).
0). Then, the leading edge position information (distance from the registration roller R115) of each sheet in the conveying path stored in the RAM 184 and the position information (the position of the roller R (i) corresponding to the clutch C (i) stored in the ROM 182 ( The distance from the registration roller R115) to the clutch C
It is determined whether the roller R (i) corresponding to (i) holds the sheet (S812). When it is determined that the roller R (i) holds the sheet, the leading end position information of each sheet in the conveyance path stored in the RAM 184 and the ROM.
By referring to the position information of the other rollers stored in 182, it is determined whether the sheet nipped by the roller R (i) is nipped by the downstream roller (the roller on the photosensitive drum 152 side) (S814). . If the sheet nipped by the roller R (i) is not nipped by the downstream roller, clutch connection processing described later is performed (S816),
One is added to the variable i (S818). When it is determined in step S812 that the roller R (i) does not sandwich the sheet, or when it is determined that the sheet sandwiched by the roller R (i) is sandwiched by the downstream roller, the process proceeds to step S818. . After step S818, the variable i is 1
It is determined whether the number is 4 (S820). If the number is not 14, the process returns to step S812. When the variable i becomes 14, the process returns to the sheet feeding control of FIG.

20 and 21 are flowcharts of the clutch connecting process called in the above-described sheet feeding resuming process. A program for executing this flowchart is stored in the ROM 182, read by the CPU 180, and executed. In the clutch engagement process, first, the current time-t (i) is calculated and set in the variable DT (S9).
00). Then, it is determined whether the sheet is being fed from the sheet feeding cassettes D108, D109 or the sheet feeding deck D110 (S902), and the sheet feeding cassettes D108, D1 are determined.
09 or the paper feed deck D110, the leading end position information of each sheet in the conveyance path stored in the RAM 184, the roller position information stored in the ROM 182, and the roller type. See the information
It is determined whether the sheet nipped by the roller R (i) is nipped by the separation roller (S904). Laura R
When the sheet sandwiched in (i) is sandwiched by the separation rollers, even if the sheet is sandwiched by another roller, it is affected by the separation roller having a short stop time. Therefore, the waiting time variable WT ΔTA (1) is set to (S906).

When it is determined in step S904 that the sheet nipped by the roller R (i) is not nipped by the separation roller, the ROM 182 and the RAM 1 are similarly to the above.
With reference to 84, it is determined whether the sheet held by the roller R (i) is held by the bearing bearing rubber roller (S908). When it is determined that the sheet sandwiched by the roller R (i) is not sandwiched by the bearing bearing rubber roller, the sheet is sandwiched only by the sintered bearing rubber roller, so ΔTA (2) is set to the variable WT. Yes (S910). If it is determined that the sheet sandwiched by the roller R (i) is sandwiched by the bearing bearing rubber roller, the ROM 182 and the RAM 182 are processed as described above.
With reference to 184, it is determined whether the sheet held by the roller R (i) is held by the sintered bearing rubber roller (S912). When it is determined that the sheet sandwiched by the roller R (i) is sandwiched by the sintered bearing rubber roller, the sheet is sandwiched by the sintered bearing rubber roller and the bearing bearing rubber roller, and therefore the variable WT is Δ.
TA (3) is set (S914). Laura R (i)
When it is determined that the sheet sandwiched by the sheet is not sandwiched by the sintered bearing rubber roller, the sheet is sandwiched only by the bearing bearing rubber roller, and therefore the variable WT is ΔTA (4).
Is set (S916).

In step S902, the paper feed cassette D10
If sheets are being fed from a sheet feeding section other than 8, D109 and sheet feeding deck D110, it is determined whether sheets are being fed from sheet feeding deck D111 (S918). When the sheet is being fed from the paper feed deck D111, the ROM 182 and the RAM 184 are referred to in the same manner as described above, and it is determined whether or not the sheet nipped by the roller R (i) is nipped by the separation roller (S920). . When it is determined that the sheet nipped by the roller R (i) is nipped by the separation roller, even if the sheet is nipped by another roller, the sheet is affected by the separation roller having a short stop time. Set ΔTA (5) to WT (S92)
2). When it is determined that the sheet nipped by the roller R (i) is not nipped by the separation roller, the ROM R182 and the RAM 184 are referred to in the same manner as described above, and the roller R
It is determined whether the sheet sandwiched in (i) is sandwiched by the bearing bearing sponge roller (S924). If the sheet sandwiched by the roller R (i) is not sandwiched by the bearing bearing sponge roller, the sheet is sandwiched only by the sintered bearing rubber roller, so the variable W
ΔTA (6) is set in T (S926). Laura R
When the sheet sandwiched in (i) is sandwiched by the bearing-bearing sponge roller, the sheet is sandwiched by the sintered bearing rubber roller and the bearing-bearing sponge roller, so ΔTA (7) is set in the variable WT. (S928). In step S918, the paper feed deck D111
If the sheet is being fed from the
(8) is set (S930).

In the image forming apparatus of this embodiment, the measured data is used when the sheet of the same size as the sheet used in the clutch measurement mode is fed in the sheet feeding control. The sheet used in the clutch measurement mode is used. When a sheet of a larger size is sandwiched by three or more rollers, and there is a combination of rollers not measured in the clutch measurement mode, among the plurality of areas to which the rollers sandwiching the sheet belong, Select the data with the shortest time from clutch release to stop.

Steps S906, S910, S914,
After data is set to the variable WT in S916, S922, S926, S928, and S930, the variable WT is changed to the variable T.
It is determined whether it is larger than WT (S932). When the variable WT is larger than the variable TWT, WT-TWT is calculated and set in the variable WT (S934), and the variable WT is changed to the variable TWT.
In the following cases, 0 is set to the variable WT (S936).
Here, the drive timing of the clutch corresponding to the roller nipping the succeeding sheet is adjusted in accordance with the delay in driving the clutch corresponding to the roller nipping the preceding sheet.

After data is set in the variable WT in steps S934 and S936, it is determined whether the variable WT is larger than the variable DT (S938). When the variable WT is larger than the variable DT, DT is set in the variable WT (S94
0). When the temporary release time of the clutch C (i) is shorter than the delay time of clutch engagement, that is, the time required to stop the roller (sheet stop), the amount of advance of the sheet during the temporary release of the clutch C (i) is the roller R ( i) Since the amount of advance of the seat before stopping does not occur, the maximum is the clutch C
This is because the temporary release time of (i) may be delayed. Then, it is determined whether the variable WT is larger than 0 (S9).
42). If the variable WT is less than or equal to DT in step S938, the process proceeds to step S942. If the variable WT is greater than 0 in step S942, wait for the WT time (S94
4), connect the clutch corresponding to the roller holding the sheet held by the clutch C (i) and the roller R (i) (S946). At this time, the variable T
The value obtained by adding WT to WT is set in the variable TWT (S9).
45). If the variable WT is 0 in step S942, the flow advances to step S946 to immediately connect the clutch corresponding to the roller holding the sheet held by the clutch C (i) and the roller R (i). And FIG.
The process returns to the sheet feeding restart process.

[0076]

As described above, according to the first aspect of the present invention, among the plurality of paper discharge trays, the one that has no sheets is discharged to the one that has been conveyed for the clutch measurement processing. By printing on paper, there is no risk of being mixed into a sheet conveyed by a user request.

Further, according to the second aspect of the present invention, even if the sheets requested by the user are ejected from all the ejection trays, the double-sided path 156 is a conveyance path that does not affect the subsequent clutch measurement processing. By temporarily ejecting the sheet, it is possible to eliminate the possibility that the sheet is mixed with the sheet conveyed by the user request.

According to the third aspect of the present invention, the image for the clutch measurement process is not directly distinguished from the sheet for the clutch measurement process at the sheet discharge place, but the image is directly displayed on the sheet for the clutch measurement process. The sheets are distinguished by printing. In this case, even if there is a sheet in the sheet discharge tray or the double-sided path, the sheet can be discharged without any problem, and the determination of the identification becomes more accurate.

[Brief description of drawings]

FIG. 1 is a diagram showing an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of sheet conveyance in the printer 100.

FIG. 3 is a block diagram of clutch control.

FIG. 4 is a diagram showing a configuration for measuring characteristics of a roller when the clutch is engaged after the clutch is released.

FIG. 5 is a diagram showing characteristics of the roller when the clutch is engaged after the clutch is released.

FIG. 6 is a diagram showing the movement of the leading edge of the sheet when the correction for ΔTA is not performed.

FIG. 7 is a diagram showing a distance from the rear end of the sheet SH1 to the front end of the sheet SH2.

FIG. 8 is a diagram showing a configuration of a flag type sensor.

FIG. 9 is a diagram showing a configuration of an optical sensor.

FIG. 10 is a diagram showing the movement of the leading edge of the sheet when the correction for ΔTA is performed.

FIG. 11 is a diagram showing a measurement area in a clutch measurement mode.

FIG. 12 is a flowchart of a clutch measurement mode.

FIG. 13 is a flowchart of a clutch measurement mode.

FIG. 14 is a flowchart of a clutch measurement mode.

FIG. 15 is a flowchart of a clutch measurement mode.

FIG. 16 is a flowchart of a clutch measurement process.

FIG. 17 is a flowchart of sheet feeding control.

FIG. 18 is a flowchart of a sheet feeding temporary stop process.

FIG. 19 is a flowchart of a sheet feeding restart process.

FIG. 20 is a flowchart of a clutch connecting process.

FIG. 21 is a flowchart of a clutch connecting process.

FIG. 22 is a diagram showing a clutch adjustment value measurement screen in a service mode.

FIG. 23 is a diagram showing a clutch adjustment value measurement screen in a service mode.

[Explanation of symbols]

100 image forming apparatuses R100 to R103, R105 to R114, R201,
R202 roller R115 registration rollers C100 to C103, C105 to C115, C201,
C202 Clutch S100 to S115, S201, S202 Sensor 120 Motor 152 Photosensitive drum D108, D109 Paper feed cassette D110, D111, D200 Paper feed deck

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Manabu Yamauchi             Kyano, 3-30-2 Shimomaruko, Ota-ku, Tokyo             Within the corporation (72) Inventor Ichiro Sasaki             Kyano, 3-30-2 Shimomaruko, Ota-ku, Tokyo             Within the corporation (72) Inventor ▲ Yoshi ▼ Tomoyasu Kawa             Kyano, 3-30-2 Shimomaruko, Ota-ku, Tokyo             Within the corporation F-term (reference) 2H072 AA13 AA29 AB08 AB27                 3F049 AA10 DA12 EA01 EA23 EA24                       EA29 LA02 LB03                 3F053 EA02 EB01 EB04 EC02 ED14                       ED29 ED31 LA02 LB03

Claims (3)

[Claims] 1. A first, a second and a third roller for conveying a sheet, a drive means for driving the first, second and third rollers, a drive force of the drive means for the first, First, second and third clutches for transmitting to the second and third rollers; control means for controlling engagement and disengagement of the first, second and third clutches; and the first and second clutches Data relating to the stop characteristics of the sheet when the first and second clutches are released while the roller is sandwiching the sheet, and the second and third rollers are sandwiching the sheet. In a sheet conveying apparatus having storage means for storing second data regarding sheet stop characteristics when the second and third clutches are released, and a plurality of paper discharge paths and a plurality of paper discharge trays. The control means is stored in the storage means. 1st and 2nd
The first, second and third based on any of the data
The plurality of paper discharge trays in order to control the connection timing of the clutches and to distinguish the sheet conveyed to obtain the first and second data stored in the storage means from the sheet conveyed from the user request The sheet conveyed to obtain the first and second data stored in the storage unit is discharged to the discharge tray for which no sheet is detected by the detection unit that detects the sheet for each of the sheets. A sheet conveying device characterized by: 2. The sheet conveying apparatus according to claim 1, wherein when the detection unit detects sheets in all of the plurality of discharge trays, the first and second data stored in the storage unit are stored. A sheet conveying apparatus, which discharges a sheet conveyed to obtain the first and second data stored in the storage means, to a conveying path that does not affect the obtaining. 3. An image forming means, first, second and third rollers for conveying a sheet, driving means for driving the first, second and third rollers, and a driving force of the driving means. A first, a second and a third clutch for transmitting the electric field to the first, second and third rollers, control means for controlling connection and disengagement of the first, second and third clutches, The first data regarding the stop characteristic of the sheet when the first and second clutches are released while the first and second rollers are holding the sheet and the second and third rollers are the sheet. A sheet conveying device having a storage unit that stores second data relating to a stop characteristic of the sheet when the second and third clutches are released while the sheet is sandwiched by the control unit. First and second stored in
The first, second and third based on any of the data
The image forming apparatus controls the connection timing of the clutch to distinguish the sheet conveyed to obtain the first and second data stored in the storage unit from the sheet conveyed from the user request. A sheet conveying apparatus, which prints on a sheet an image indicating that the sheet has been conveyed to obtain the first and second data stored in the storage means.