JPH0820144A - External paper supply unit for image making apparatus - Google Patents

Abstract

PURPOSE:To install many paper supply cassettes easily as optional equipment in an image making apparatus such as a copying machine without using a control means such as CPU inside the unit even when a multi-core cable with limited signal lines between an image making apparatus main body and the unit and a connector are used. CONSTITUTION:Each paper supply cassette is equipped with driving electromagnetic clutches 21, 22, paper size detection units 31, 32, and paper detection units 81, 82 so that control can be conducted by the cassettes using common signals. According to a selection signal (SELECT) inputted from the image making apparatus main body, a control signal from the main body is changed over by switch circuits 2, 3, 8 to supply the signal to the corresponding electromagnetic clutches of the paper supply cassettes and the detection units.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external sheet feeding unit for an image forming apparatus having a plurality of sheet feeding cassettes (sheet feeding trays) optionally provided.

[0002]

2. Description of the Related Art For example, an external paper feeding unit optionally installed in a copying machine includes driving parts such as a driving motor and an electromagnetic clutch for mechanically driving the respective parts in the unit, and a paper feeding cassette. There is a detection component for detecting the presence / absence of paper, the paper size, and the paper position during paper feeding. The driving component and the detecting component are electrically connected to the system controller of the copying machine body by a multi-core cable having a connector, and are directly controlled by the system controller.

[0003]

However, in the conventional external sheet feeding unit for an image forming apparatus as described above, if the number of sheet feeding cassettes increases, the number of sheets fed from the image forming apparatus main body is proportionally increased. Therefore, there is a problem that the number of control signals increases, and therefore a multi-core cable with a limited signal line and a connector of a general shape cannot handle unless a control means such as a CPU is provided in the unit. .

The present invention has been made by paying attention to the above problems, and even in the case of a multi-core cable and a connector having a limited signal line, a large number can be easily provided without using a control means such as a CPU inside. It is an object of the present invention to provide an external sheet feeding unit for an image forming apparatus, which can have the sheet feeding cassette.

[0005]

An external sheet feeding unit for an image forming apparatus according to the present invention has a plurality of sheet feeding cassettes, and each sheet feeding cassette is provided with a sheet feeding driving unit and a sheet detecting unit. A switching means for switching the control signal of the paper feed cassette input from the image forming apparatus main body in accordance with the paper feed cassette selection signal input from the image forming apparatus main body,
The control signal from the main body of the image forming apparatus is supplied to the drive means and the detection means of the paper feed cassette selected by the selection signal via the switching means.

[0006]

In the external sheet feeding unit for the image forming apparatus of the present invention, the control signal of each sheet feeding cassette input from the image forming apparatus main body is supplied by the switching means in accordance with the selection signal from the image forming apparatus main body. It is sent to the drive means and the detection means of the paper cassette.

[0007]

FIG. 1 is a diagram showing a circuit configuration of an embodiment of the present invention. Here, an external sheet feeding unit for a copying machine having two sheet feeding cassettes is shown. Each of them is provided with a driving means for paper feeding and a paper detecting means.

In the figure, reference numeral 1 is a selection signal (SE) from the copying machine main body for selecting the above two paper feed cassettes.
LECT input terminals 2, 3 and 8 are selection signals (S
In accordance with ELECT, a switch circuit (switching means) for switching the control signal from the main body of the copying machine supplies the control signal to the drive means and the detection means of the paper feed cassette selected by the selection signal.

Reference numeral 10 is a control signal (DRI) for driving the drive motor 14 in the paper feeding unit from the copying machine main body.
VE) input terminal, 13 is a drive circuit for driving the motor 14, (Driver), 20 is a common control signal (CL-ON) input for controlling ON / OFF of the electromagnetic clutches (driving means) 21 and 22. At the terminal, the electromagnetic clutch 21
Is an electromagnetic clutch (CL1) for transmitting the driving force of the motor 14 to a drive system required for paper feeding from the upper paper feeding cassette,
The electromagnetic clutch 22 is an electromagnetic clutch (CL2) that transmits the driving force of the motor 14 to a drive system required when the paper is fed from the lower paper feed cassette.

Reference numeral 30 is an input terminal for a request signal (SIZE) for detecting the paper size of the paper feed cassette on the main body side.
1 is a paper size detection unit (detection means) that detects the paper size used in the upper paper feed cassette and outputs 4-bit detection data, and 32 is the paper size used in the lower paper feed cassette Paper size detection unit (detection means) for outputting 4-bit detection data,
50, 60, and 70 are request signals (SIZ
The paper size detected in response to E) is 4 bits (b0,
b1, b2, b3) is an output terminal for outputting as data, and the detection data of each unit 31, 32 are diodes 41, 51, 61, 71 and 42, 52, 62, 72.
Is output through.

Reference numeral 80 is an input terminal for a request signal (PAPER) for checking the presence / absence of paper in the paper feed cassette, and 81 is a paper detection unit for detecting the presence / absence of paper in the upper paper feed cassette. Detecting means), 82 is a paper detecting unit (detecting means) for detecting the presence / absence of paper in the lower paper feed cassette, and 90 is a paper presence / absence signal (REMA) in response to the paper presence / absence check request signal (PAPER).
IN) is an output terminal for outputting.

FIG. 2 is a schematic view showing an example of a state in which the paper feeding unit having the above structure is connected to the copying machine main body. In the figure, 1
Reference numeral 00 denotes a copying machine main body, which is connected to the above-described external paper feeding unit 200 by a multi-core cable 210 for interface and a connector 211. Further, the paper feeding unit 200 includes an upper paper feeding cassette 201 and a lower paper feeding cassette 2
02 is provided.

The paper feeding unit 20 configured as described above
0, electromagnetic clutches 21 and 22 are provided as sheet feeding drive means for each of the sheet feeding cassettes 201 and 202,
In addition, the paper size detection unit 3 is used as a paper detection unit.
1, 32 and sheet detection units 81, 82 are provided. Then, the control signals of the electromagnetic clutches 21 and 22 and the detection units 31, which are input from the copying machine main body 100,
The control signals (request signals) 32, 81, 82 are switched by the switch circuits 2, 3, 8 according to the selection signal input from the copying machine main body 100, and the corresponding electromagnetic clutches 21, 22 and the paper size detection unit 31. , 32 and the paper detection units 81, 82.

Here, the control signal from the main body 100 of the copying machine is shared by the sheet feeding cassettes 201 and 202. The control signal is switched by the switch circuits 2, 3 and 8 to correspond to the sheet feeding cassette 201. , 202, the multi-core cable 2 with limited signal lines
Even with 10 and the connector 211, it is possible to easily have a large number of paper feed cassettes without using a control means such as a CPU inside the unit.

FIG. 3 is a flow chart showing an example of the control operation on the copying machine main body side according to this embodiment. Step 30
When this control operation starts in step 1, first, step 30
In 2, the selection signal (SELECT) is set to select the upper sheet feeding cassette 201. And step 3
In 03, it is determined which of the two paper cassettes the operator has selected, and if the lower paper cassette 2
If No. 02 is selected, the selection signal (SELEC
T) is set and the process proceeds to step 305.

At this point, if the upper sheet feeding cassette 201 is selected, all the three switch circuits 2, 3 and 8 are set to the upper sheet feeding cassette side, and the upper electromagnetic clutch 21 and the upper electromagnetic feeding clutch 21 are set. The sheet size detection unit 31 and the upper sheet detection unit 81 are selected. Also,
If the lower sheet cassette 202 is selected, the lower electromagnetic clutch 22, the lower sheet size detection unit 32, and the lower sheet detection unit 82 are selected.

Then, in the above-mentioned state, the paper size detection request signal (SIZE) is output, and b0, b1, and
The 4-bit response signals b2 and b3 are read to detect the paper size and displayed on the display panel of the operation unit (not shown) on the copying machine main body side. Next, in step 306, a paper presence / absence check request signal (PAPER) is output, the response of the presence / absence signal (REMAIN) at this time is read, and if there is no paper, the fact is displayed on the display panel, and the process returns to step 302. If there is paper, it is determined in step 307 whether or not the copy start key provided in the operation unit is pressed. If it is pressed, the copy processing routine is started in step 308, and after the copy start key is completed. If is not pressed, the process directly returns to step 302.

In the above embodiment, ordinary switches are shown as the switch circuits 2, 3 and 8 for switching, but logic circuits such as multiplexers are used instead of mechanical switches such as relays. You may process it. In addition, the electromagnetic clutch 21 illustrated in this embodiment,
22 as well as the paper size detection units 31 and 32 and the paper detection units 81 and 82, the same kind of switching is also required when a plurality of the same kind of sensors or drive components corresponding to the plurality of paper feed cassettes are required. Can be controlled.

Further, if the number of paper feed cassettes is three or more, the selection signal (SELECT) is set to a plurality of lines, and 4-bit and 8-stage paper feed cassettes can be handled as 2-bit or 3-bit signals, respectively. You can

[0020]

As described above, the control signal from the image forming apparatus main body is switched according to the selection signal input from the image forming apparatus main body, and the sheet feeding cassette selected by the operation unit on the image forming apparatus main body side. By supplying the driving means and the detecting means of the multi-core cable with a limited signal line,
The connector can also have a large number of paper feed cassettes without providing a control unit such as a CPU in the paper feed unit.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an example of connection to the main body of the copying machine.

FIG. 3 is a flowchart showing the operation of one embodiment 1, 20, 30, 80 Input terminals 2, 3, 8 Switch circuit (switching means) 21, 22 Electromagnetic clutch (driving means) 31, 32 Paper size detection unit (detection) Means) 81, 82 Paper detection unit (detection means) 100 Copier main body (image forming apparatus main body) 200 External paper feed unit 201, 202 Paper feed cassette 210 Multicore cable 211 Connector

Claims (1)

[Claims] 1. A plurality of paper feed cassettes, each paper feed cassette having a paper feed drive means and a paper detection means,
A switching unit is provided for switching the control signal of the sheet feeding cassette input from the image forming apparatus main body in accordance with the sheet feeding cassette selection signal input from the image forming apparatus main unit, and from the image forming apparatus main unit via the switching unit. An external sheet feeding unit for an image forming apparatus, characterized in that the control signal is supplied to the driving unit and the detecting unit of the sheet feeding cassette selected by the selection signal.