JPH03223033A - Sheet supplier - Google Patents

Abstract

PURPOSE:To mount a sheet supplier in no relation to a conveying speed of a sheet conveyer by providing a means for detecting the proper sheet conveying speed possessed by the sheet conveyer, and a means for changing a paper feed interval and/or a paper feed speed of the sheet supplier based on a detected result. CONSTITUTION:A sheet supplier 2 is provided with a storage part 21 and a supply roller 22 for feeding a transcription material stored in this storage part 21, and a sheet conveying speed is calculated from the time for passing between sensors SW1, SW2 or a paper feed interval and a paper feed speed of the supplier 2 are changed based on the sheet conveying speed, by providing the transcription material-detecting sensors SW1, SW2 while having a control part 23 downstream from the supply roller 22. The sheet conveying speed is obtained from a relation concerning a mechanically predetermined distance between both sensors by obtaining the time for passing between the sensors SW1, SW2. After the conveying speed of a sheet conveyer 1 is detected, the paper feed interval and the paper feed speed or any of these interval and speed of the supplier 2 itself are made to match the paper feed speed of the conveyer 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a large-capacity cassette or the like which is removably attached to a transport device used in an image forming apparatus, etc. and which itself has a supply function. This invention relates to improvement of a sheet feeding device.

(Prior Art) Image forming apparatuses such as copying machines have conventionally been equipped with sheet conveying devices for conveying sheet-shaped transfer materials. The transfer material is normally supplied to the conveying device from a relatively compact paper feed cassette that stores the transfer material.

However, such paper feed cassettes have a limit to the amount of transfer material that can be stored, and are not suitable for making large quantities of copies. Therefore, a large-capacity cassette capable of storing a large amount of transfer material was installed in place of the normal paper feed cassette to handle the large number of copies.

(Problems with conventional technology) By the way, in offices where copying machines and the like are frequently used, the number of copying machines installed is increasing, but even if multiple copies from the same manufacturer are installed, There are few cases where multiple units of the same model are installed.

Therefore, even if large-capacity cassettes are moved and installed between copying machines during mass copying as described above, they will be mechanically compatible, but the large-capacity cassettes and the copying machine's transport device Due to the difference in conveyance speed, paper jams may occur between the two.

For example, large-capacity cassettes are equipped with a drive motor to drive the paper feed roller separately from the conveyance device in the main body of the copying machine, and the drive speed of this motor cannot be changed, so the drive speed of the large-capacity cassette It could only be applied to copying machines with a transport speed compatible with

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sheet feeding device that overcomes the above-mentioned conventional drawbacks.

(Means for Solving the Problems) The sheet feeding device of the present invention is a sheet feeding device that is detachably attached to a sheet conveying device that conveys a sheet-like object, and has a unique sheet conveying speed that the sheet conveying device has. The present invention is characterized by comprising a detection means for detecting the detection result, and a changing means for changing the paper feeding interval and/or the paper feeding speed of the sheet feeding device based on the detection result.

(Function) After detecting the conveying speed of the sheet conveying device to which the sheet feeding device is attached, based on the detection result, the sheet feeding device itself determines the sheet feeding interval, the sheet feeding speed, or between the sheet feeding interval and the sheet feeding speed. Either can be changed to match the paper feeding speed of the sheet conveying device.

(Example) Next, an example of the present invention will be described with reference to FIGS. 1 to 5.

FIG. 1 shows a sheet conveying device 1 and a sheet feeding device 2 of the present invention.
It is a figure showing a schematic structure of.

The sheet conveying device 1 is used as a part of a copying machine 3, which is an example of an image forming apparatus. The copying machine 3 has an image forming section 4, which includes a main charger 6, a developing device 7, a transfer charger 8, which are mainly arranged along the circumferential surface of the photoreceptor drum 5.
It includes a separation charger 9 and a cleaning device 10.

Further, various optical devices 12 are arranged at the upper part of the image forming section 4 to guide the image of the document placed on the contact glass 11 to the photosensitive drum 5. It has a reflective mirror and a roof. 20 again
is a control unit for operating the copying machine according to a predetermined procedure. The image forming process by the image forming section 4 and the optical device 2 configured as described above is well known, so the explanation thereof will be omitted.

A sheet conveying device 1 is provided below the image forming section 4 . The sheet conveyance device 1 mainly has a SW3 for detecting that a sheet-like transfer material is supplied from a paper feed cassette 13 or a sheet supply device 2 to be described later, and a copy switch is turned on when SW3 is turned on by the transfer material and the copy switch is turned on. It has a paper feed roller 14 that starts rotating when the paper is rotated. On the downstream side of the sheet conveyance device 1, a conveyance roller 24, a registration roller 15, a fixing device 16, and a discharge roller 17 are arranged, and constitute a conveyance path up to a discharge tray 18.

The sheet feeding device 2 can be attached to the attachment portion 19 of the copying machine 3 by moving it in the direction of arrow A.
Also, it can be removed by moving in the opposite direction to the direction of arrow A.

The sheet feeding device 2 is configured as follows.

That is, it includes a storage section 21 for storing the transfer material, and a supply roller 22 for feeding the transfer material from the storage section 21 toward the sheet feeding device as shown by the broken line in FIG.
On the downstream side of the paper feed roller 22, a transfer material detection sensor SWI is provided to detect the sheet conveyance speed by the sheet conveyance device 1.
, SW2 are provided. These detection sensors SWI
and SW2, the time required for the transfer material to pass between SWI and SW2 is determined, and the sheet conveyance speed of the sheet conveyance device 1 can be determined from the relationship with the mechanically determined distance between SWI and SW2. 23, the transfer material is SW as mentioned above.
A control unit that calculates the sheet conveyance speed based on the time it takes to pass between I and SW2, or changes the sheet feeding interval and sheet feeding speed of the sheet feeding device based on the sheet conveying speed of the sheet conveying device. be. As is clear from the above description, in this embodiment, the detection means for detecting the sheet conveyance speed is composed of detection switches SWI, SW2 and a part of the control section 23, and the changing means is composed of a part of the control section 23. The operation of the sheet feeding apparatus configured as described above will be explained.

Figure 2 is a schematic enlarged view of the main parts of Figure 1, Figure 3 is a flowchart showing the procedure for moving the sheet of the sheet feeding device to the initial position, and Figure 4 is determining the conveying speed of the sheet conveying device. FIG. 5 is a flowchart showing the steps of the operation performed by the sheet feeding device to determine the transporting speed of the sheet feeding device.

When a sheet feeding device is installed in a certain copying machine, the sheet conveyance speed may be different from that of the previously installed copying machine, and if the sheet feeding device is used as is, paper jams may occur. Therefore, in the present invention, after the sheet feeding device 2 is mounted on the copying machine 3 as shown in FIG. 1, a mode selection switch (not shown) of the sheet feeding device 2 is operated to change to the measurement mode. When the copying machine 3 side copies one sheet in this state, the sheet feeding device 2 changes the paper feeding interval, paper feeding speed, etc. as described later, and adjusts the sheet feeding speed of the installed copying machine. Also, the sheet can be conveyed well.

An embodiment of the present invention will be described below, and in the following embodiment, an example in which the sheet feeding interval of the sheet feeding device is changed will be described.

First, after the sheet supply bag N2 is attached to the copying machine 3, preparations are made for moving the sheets of the sheet supply device 2 to the initial position. To explain according to the flowchart in FIG. 3, after turning on the power of the sheet feeding device 2 (step S
O) If it is determined in step S1 that the SWI is not turned on, since the transfer material in the sheet supply device 2 is not at the initial position, driving of the supply roller 22 is started (step S3). When the transfer material is conveyed to the supply roller 22, the detection switches SWI and SW2 are turned on in step S4.
S5), after turning on the detection switch SW2, the supply roller 22 is stopped driving after a certain period of time has elapsed (step S6).
Step 37). In this case, the predetermined time is such that the leading edge of the transfer material comes into contact with the paper feed roller 14 of the copying machine 3 after the detection switch SW2 is turned on, and the transfer material is slightly bent in front of this roller. At this time, the detection switch SW3 on the copying machine side is turned on. Also step S
1. If it is determined in step S2 that the detection switch is ON (both Y), it is assumed that the initial settings have already been completed and no preliminary preparations are made.

After the preparation for moving the sheet to the initial position is completed in this way, the conveying speed of the sheet conveying device is measured by the sheet feeding device.

Explaining according to the flowcharts of FIGS. 4 and 5, the mode selection switch (not shown) of the sheet feeding device 2
Set it to measurement mode in advance by operating . Then, when the copy switch of the copier is turned on (step S8 in Figure 4)
), if the detection switch SW3 provided on the copying machine side is not turned on (N in step S9), the transfer material has not reached the paper feed roller 14, so the process is finished and the third
Urge the user to make preparations as shown in the illustration.

If SW3 is turned on in step S9, the initial setting of the transfer material has been completed, so the paper feed roller 14 is driven (step 510) and the transfer material begins to be fed downstream.

Then, when the rear end of the transfer material passes through SW3, the SW
3 is turned off (step 311), it is determined whether a preset time has elapsed (step 512).
), the paper feed roller 14 is stopped and the operation on the copying machine 3 side performed to determine the conveyance speed of the sheet conveyance device is completed.

The above operation itself is no different from a normal one-sheet copy operation. During this period, only the paper feed rollers 14 of the three copying machines are rotating, and the feed rollers 22 of the sheet feeding device 2 are not rotating. Therefore, the transfer material is transported forward only by the paper feed roller 14.

While the sheet conveyance device of the copying machine performs the above operations, the sheet supply device determines the conveyance speed of the sheet conveyance device in the following manner. That is, as shown in FIG. 4, before the detection switch SW3 of the sheet conveying device 3 is turned from ON to OFF when the rear end of the transfer material is detected (step 511 in FIG. 4), the detection switch SW3 of the sheet conveying device 3 is turned At the rear end, turn off the detection switch SWI of the sheet feeding device 2 (step 514 in FIG. 5).
Following F, a timer is started (step 515). Then, when the rear end of the transfer material turns off SW1 and then turns off SW2 (step 316), the timer is stopped accordingly (step Sl''?).

In this way, the transfer material conveyed by the sheet conveying device 1 is detected by the detection switches SWI and SW of the two sheet feeding devices.
It is possible to know the time t it takes to pass between the two. Step 3
1B, the detection switch SWI obtained as above,
The passage time t between SWZ and the detection switches SWI and SW2 which are mechanically known in advance on the sheet supply bag W2 side.
The sheet conveying speed vl of the sheet conveying device 1 can be determined from the distance a (see FIG. 2). Based on this sheet conveyance speed v1, parameters to be changed in order to control the sheet feeding interval of the sheet feeding device 2 are calculated (step 318). Since the paper feeding interval can be controlled in this way, even if the sheet feeding device is changed from a sheet conveying device with a relatively fast conveying speed to a sheet conveying device with a relatively slow conveying speed, the subsequent transfer material will still come in front. There is no possibility of paper jams caused by catching up with the transfer material.

The calculation performed in step 31B will be explained with reference to FIG. 2. In the transfer material conveyance direction shown by arrow B in FIG. The distance between the trailing edge of the preceding transfer material and the leading edge of the following transfer material is set to be Il when the paper is fed until it is bitten by the paper roller 14. As long as the distance L is maintained in this way, even if there is a speed difference between the sheet conveying device 1 and the sheet feeding device 2, the leading transfer material and the following transfer material will be at the same distance. Since the paper is transported by the transport system of the copying machine 3 while maintaining the , the paper can be transported without causing jams.During normal copying, as will be described later, when the trailing edge of the preceding transfer material is Since the subsequent transfer material is conveyed by the supply roller 22 after a preset time τ, 2I can be kept constant by adjusting the time τ. When the rear end reaches the detection switch SWI (detection switch S
The distance that the subsequent transfer material travels from when WI is turned OFF until it is bitten by the paper feed roller 14 is L, = 42 + f.

However, 2 is the distance from the SWI to the paper feed roller 14. During this time, the preceding transfer material is advancing under the action of the paper feed roller 14 of the sheet conveyance device, so the conveyance speed is determined at step 318 in FIG.

If we apply this, the time T required to proceed through this process can be obtained as:

Meanwhile, during this time, the leading edge of the following transfer material advances at a time Tz commensurate with the conveying speed of the sheet feeding device 2 until it is bitten by the feeding roller 14 of the sheet conveying device 2 by the feeding roller 22 of the sheet feeding device 2. If the conveying speed of the sheet feeding device 2 known in the control unit 23 is 2, then
Time T2 is T, = L z = (1+ l t )V
z V 2 . In fact, T2 is slightly affected by the speed of the paper feed roller 14 when the leading edge of the following transfer material is bitten by the paper feed roller 14, but this is ignored because the time is short.

From the above relationship, the trailing edge of the preceding transfer material is OF
The waiting time τ from when the temperature is set to F until the supply roller 22 starts driving is T, 10τ=T.

Therefore, la 1 τ= (y; 7) f −r′ l +■, given as f 2 and the value V! ,a,l,1. Since t is known in advance as a value specific to the sheet feeding device, and t is determined in the measurement mode as described above, the value ! If only , is determined and stored in the control unit 23, the setting parameters can be calculated using only two sheet feeding devices.
Therefore, no matter what kind of conveyance speed the sheet conveyance device has, it can be handled by automatically changing the settings of the sheet supplying device itself.

When performing a copying operation using the waiting time τ determined as described above, first, when the copy switch of the copying machine is turned on, the paper feed roller 14 starts to drive and conveys the transfer material forward. The rear end of this transfer material is the detection switch S.
When W1 is turned OFF, the supply roller 22 waits for a time τ, starts driving, and starts supplying the next transfer material. By doing so, it is possible to adjust the paper feeding interval to prevent a subsequent transfer material from catching up with a preceding transfer material, thereby preventing a paper jam from occurring.

In the embodiment described above, an example was given in which the sheet feeding interval by the sheet feeding device was changed, but instead of changing the sheet feeding interval,
If there is a margin to change the drive speed of the motor that drives the supply roller of the sheet supply device, this may be changed. In this case, as described in the above embodiment, the conveying speed on the sheet conveying device side is determined in advance in the measurement mode, and the control section in the sheet feeding device is set to have the same speed as this speed. All you have to do is rewrite.

Further, instead of changing each of the paper feeding interval and the paper feeding speed individually, it is also possible to change both at the same time.

Further, in this embodiment, an example in which the sheet conveyance device is applied to a copying machine has been described, but the present invention is not limited to this, and the present invention can also be applied to a sheet conveyance device used in a printer or the like.

(Effects) Since the sheet feeding device of the present invention is configured as described above, the sheet feeding device can be installed regardless of the conveying speed of the sheet conveying device, and various parameters can be automatically set without troublesome operations. can.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a schematic configuration of the C) II feeding device and sheet feeding device of the present invention, Fig. 2 is a schematic diagram enlarging the main parts of Fig. 1, and Fig. 3 is a diagram showing the initialization of sheets in the sheet feeding device. FIG. 4 is a flowchart showing the steps of the operation performed by the sheet transporting device to determine the transporting speed of the sheet transporting device, and FIG. 5 is a flowchart showing the procedure for determining the transporting speed of the sheet transporting device. 3 is a flowchart showing the procedure of operations performed by the sheet feeding device. 1... Sheet conveyance device 2... Sheet supply device 14... Paper feed roller 22... Supply roller 23... Control unit 24... Conveyance roller

Claims (1)

[Claims] (1) A sheet feeding device detachably attached to a sheet conveying device that conveys a sheet-like object, which includes a detection means for detecting a sheet conveying speed specific to the sheet conveying device, and a sheet feeding device based on the detection result. 1. A sheet feeding device comprising: changing means for changing a sheet feeding interval and/or a sheet feeding speed of the device.