JPH0430585B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper feeding device for a copying machine that automatically superimposes thick paper with a small area and paper with a larger area when manually copying the paper.

As a conventional copying machine paper feed device, for example, the first
As shown in the figure, there is a paper feed cassette 3 which can be inserted into and taken out from the side (or front) of the copying machine main body 1 and in which copy paper 2 of a required size is loaded, and the paper feed cassette 3.
The automatic paper feed roll 6 feeds the topmost copy paper to the transfer unit 5 side provided near a predetermined position of the photosensitive drum 5, and the paper feed cassette 3 indicates that one copy paper has been delivered. Paper feed sensor 7 to detect
is provided. In addition to these configurations,
A manual feed tray 8 disposed above the paper feed cassette 3 and movable in the direction of the arrow, a manual feed sensor 9 for detecting manually fed copy paper, and a manual paper feed roll 10 for feeding the manually fed copy paper to the transfer unit 5 side.
, a transport roll 11 that sends out the copy paper from the automatic paper feed roll 6 or the manual feed tray 8, and an image alignment (or registration) roll 12 that sends the paper from the roll 11 to the transfer unit 5 at a predetermined timing. A guide 13 is provided for aligning the copy paper from the image alignment roll 12 with the photosensitive drum 4.

In the above configuration, when performing continuous copying, by pressing the copy start button, the set number of sheets are sequentially sent out from the paper feed cassette 3 by the paper feed roll 6. The number of copy sheets sent out is detected by the paper feed sensor 7, and the number of remaining sheets is displayed on the console.

When copy paper is inserted from the manual feed tray 8 during continuous copying, the manual feed sensor 9 outputs a detection signal, an interrupt is generated, the operation of the automatic paper feed roll 6 is stopped, and the manual feed roll 9 is stopped. rotates, and only manually fed copy paper is fed out.

By the way, when manually copying thick paper with a small area such as official postcards, the electrostatic conveyance force by the photoreceptor drum 4 (the paper that leaves the guide 13 is attracted to the drum by static electricity) is applied to a small area. And because it is thick, it cannot be obtained sufficiently. Therefore, in order to increase the electrostatic conveyance force, a method is sometimes used in which the paper is overlapped with another paper having a large area as shown in FIG. 2, and the paper is fed out from the manual feed tray 8 at the same time. This increases the electrostatic conveyance force of the drum, making it possible to reliably convey thick paper with a small area.

However, in the case of conventional paper feed devices for copying machines,
Since two sheets of paper are stacked and inserted from a manual feed tray, alignment errors are likely to occur and sufficient electrostatic conveying force may not be obtained.

The present invention has been made in view of the above,
To provide a paper feeding device for a copying machine which automatically superposes two sheets so that the superposition with a supplementary paper is accurately carried out when making thick, small-sized manual copies.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The paper feed device for a copying machine according to the present invention will be described in detail below.

FIG. 3 shows an embodiment of the present invention, in which the same parts as shown in FIG. Although omitted, the paper feed tray 20 is attached to the spring 21 from the lower part of the feeding side.
a paper presser lever 22 which is pushed up by the uppermost paper surface of the tray and applies a force against the spring 21 at a predetermined time; and the lever 2.
This embodiment differs from the one shown in FIG. 1 in that solenoids 23 are provided to drive the motors 2 at predetermined times.

Further, the configuration of the control unit includes a microcomputer 30 that receives the outputs of the paper feed sensor 7, manual feed sensor 9, and small size copy button 24 as input information and outputs control commands;
a drive circuit 25 that operates according to control commands output from the microcomputer 30 to drive the solenoid 23; and a drive circuit 26 that operates according to control commands output from the microcomputer 30 to control the motor 60 that drives the paper feed roll 6. and microcomputer 3
The drive circuit 27 operates in response to a control command output from a drive circuit 27 that controls a motor 100 that drives a manual paper feed roll 10. Here, the microcomputer 30 uses various sensors and switches (not shown) of the small-size copy button 24 as information sources to control the paper feed according to the present invention, as well as a series of processes related to the scanning system, conveyance system, and drum rotation. It executes control and consists of an input interface 32 that takes in each output signal of the sensor and switch, converts it into a digital signal, and sends it to the bus line 31 as data;
ROM that stores the program that controls the roller motor and performs all controls associated with copying.
33, a CPU 34 that performs various calculations and judgment processes according to the programs in the ROM 33 and generates various control commands, and a RAM 35 that temporarily stores calculation values or data by the CPU 34.
Output interface 36 that sends control commands from the CPU 34 to an external circuit from a predetermined output port
It consists of

In the above configuration, in normal automatic paper feeding copying, the copy paper is carried out from the paper feed tray 20 by the paper feed roll 6, and then is brought into alignment with the image of the optical system by the conveyance roll 12 using a clutch (not shown). The image is sent out to the drum 4 at the same timing, and the transfer is performed. In addition, when copying by hand, the manually fed paper and the copy paper in the paper feed tray 20 (for example,
The conveyance time is controlled so that the sheets (such as A4 sheets, which are sufficiently large compared to manually fed sheets) arrive at the image alignment roll 12 at the same time. When copying onto thick, small-sized paper such as official postcards, press the small-size copy button 24, then insert the paper into the manual feed tray 8, and the manual paper feed sensor 9 outputs a detection signal. Based on this detection signal and the output signal of the small size copy button 24, the microcomputer 30 issues a control command to the drive circuits 26 and 27 to rotate the motors 60 and 100. In this case, the distance ₁ from roll 6 to roll 12,
It is convenient if the distance ₂ from roll 10 to roll 12 is equal, but if they are different, the rotational speed of one of rolls 6 or 10 is controlled so that they arrive at roll 11 at the same time.

Note that in normal manual copying, it is only necessary to insert the manual copy paper into the manual tray 8 without operating the small size copy button 24.
As a result, the manual feed sensor 9 outputs a detection signal,
Based on this signal, the microcomputer 30 issues control commands to the drive circuits 25, 26, and 27,
Solenoid 23 is driven and motors 60 and 100 rotate.

However, the solenoid 23 is not connected to the paper presser lever 22.
, and pushes the paper feed tray 20 downward as shown in FIG. 4 so that it is in a non-contact state with the paper feed roll 6, so that only the manual paper feed roll 10 functions regardless of the rotation of the paper feed roll 6. Only manually fed copy paper is conveyed toward the image alignment roll 12.

As explained above, according to the paper feeding device for a copying machine of the present invention, when making a manual copy of a thick small size, the assistance paper can be automatically fed out from the automatic paper feed tray at the optimal timing and overlapped with the manual paper. Therefore, the conveyance force is improved, and the electrostatic tack force of the drum and the conveyance performance of the transport after the drum can be improved.

[Brief explanation of drawings]

FIG. 1 is a system configuration diagram of a conventional paper feeding device for a copying machine. FIG. 2 is an explanatory diagram of the conventional method when manually feeding thick small size paper. FIG. 3 is a configuration diagram showing an embodiment of the present invention. FIG. 4 is an explanatory diagram showing the operation of the paper presser lever according to the present invention during normal manual copying. Explanation of symbols, 4...Photosensitive drum, 5...Transfer section, 6...Paper feed roll, 7...Automatic paper feed roll,
8... Manual feed tray, 9... Manual feed sensor, 1
0... Manual paper feed roll, 11... Conveyance roll,
12... Image alignment roll, 20... Paper feed tray, 2
1...Spring, 22...Paper presser lever, 2
3... Solenoid, 24... Small size copy button, 25, 26, 27... Drive circuit, 30... Microcomputer, 60, 100... Motor.

Claims (1)

[Scope of Claims] 1. A first paper feeding means for feeding copy paper from a paper feed tray to a transfer section, a second paper feeding means for feeding manual copy paper to the transfer section, and a first paper feeding means for feeding copy paper from a paper feed tray to a transfer section; In the copying machine, the copying machine includes a control unit that interrupts the operation of the first paper feed unit and operates the second paper feed unit when the copy paper is received by the manual feed tray. for a copying machine, characterized in that when superimposition of the paper is instructed, the operation of the first paper feeding means is inhibited from the middle stage, and the copy paper to be superimposed on the manual copy paper is fed synchronously with the manual copy paper. Paper feed device.