JPH03115039A - Paper feed sensor - Google Patents

Abstract

PURPOSE:To form a paper feed sensor directly mountable onto a base plate of a control system, positioned in the interior side of a device main unit, by providing a shaft member at a right angle with the conveying direction of recording paper in a lower side of a guide plate, and providing an acting piece of shape, protruded from a grooved part provided in the guide plate, and a connecting piece, in the shaft member. CONSTITUTION:A bent part 102A of a connecting piece 102 in a paper feed sensor is inserted into a long hole 103A of a side plate 103 and protruded through its back surface to intercept an optical path of a photosensor 106 of the paper feed sensor, directly connected to a printed base board 105 in a control part, with the photosensor 106 placed in an off condition. Next, recording paper passes through a paper feed guide with an acting piece 100 of the paper feed sensor pressed by the point end of the recording paper, when the acting piece is rotated in the counterclockwise direction, also the connecting piece 102 is rotated in the same direction through a shaft member 101 to switch the photosensor 106 to an on-condition. By receiving a signal of the sensor to the control part, a conveying condition of the recording paper is judged normal with conveying action further continued.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the mounting position of a paper feed sensor installed in a copying machine or the like to detect the passage of recording paper.

[Background of the invention]

Copying machines that use recording paper as an image transfer material are equipped with paper feed sensors that can detect the passage or presence of recording paper at key points in the conveyance path, for the purpose of monitoring the conveyance status of the recording paper or the timing of paper feeding. will be placed.

This paper feed sensor generally uses a photosensor, and a member such as an actuator that is rotated by the leading edge of the moving recording paper sends a signal to the control unit by opening or closing the optical path of the photosensor. It uses a system that displays the transportation status or activates related functions.

Therefore, in this case, it is necessary for the recording paper to rotate members such as the aforementioned actuator reliably, and for this purpose, the actuator and accompanying paper feed sensor should also be located at the center of the paper width. many.

[Problem that the invention seeks to solve]

On the other hand, due to the structure of the unit, the control unit that receives signals from the paper feed sensor is located further back on the side panel toward the back of the device body, so there is a large gap between it and the paper feed sensor, and it is necessary to connect it with a lead. In reality, a lot of effort and time are spent on tasks such as soldering the terminals at both ends of the lead wires and routing the east wire.

As a result of solving this problem and improving the present invention, it is an object of the present invention to provide a paper feed sensor that can be used by directly connecting to a printed circuit board constituting a control section regardless of the position of the actuator.

[Means for solving problems]

The above purpose is to provide a shaft member on the lower side of the guide plate at right angles to the conveyance direction of the recording paper, and the shaft member is provided with an actuating piece and a contact piece that protrude from the groove portion provided on the guide plate. This is achieved by a paper feed sensor characterized in that when the recording paper presses down and passes the actuating piece, the contact piece turns on and off a photosensor provided on the substrate.

〔Example〕

An embodiment of the invention is shown in FIGS. 1 and 2.

FIG. 1 shows a conveyance path of recording paper in a color image forming apparatus.

10 is a photosensitive drum, and 41 to 44 are developing devices each containing magenta, yellow, cyan, and black toners, and the process of charging, exposing, and developing is repeated each time the photosensitive drum 10 rotates. Monochromatic toner images are developed by each of the developing devices, and a color toner image is synthesized on the surface of the photoreceptor drum 10 by overlapping them.

Reference numeral 50 denotes a paper feed cassette, and 51 indicates a sorting roller. The stacked recording sheets in the paper feed cassette 50 are carried out and fed one by one starting from the top layer by the action of the sorting roller 51.

Reference numerals 61 and 62 are a first paper feed roller and a second paper feed roller, respectively, which are in a constantly rotating state, and 71 and 72 are paper feed guides each having an arc shape or a linear shape.

The recording paper carried out 1 from the paper feed cassette 50 is
The sheet is sent by the sheet feed roller 61 along the sheet feed guide 71 and after making a U-turn, that is, upside down, comes into contact with the rising portion of the sheet feed shutter S that blocks the conveyance path of the sheet 72 and is temporarily stopped. In this case, the second paper feed roller 62 continues to rotate while slipping on the surface of the recording paper that is in a stopped state.

An actuation piece 100 for activating a paper feed sensor for detecting a jam, which will be described later, is disposed on the conveyance path immediately before the second paper feed roller 62, and the actuation piece 100 is conveyed and pressed by the leading edge of the recording paper. counterclockwise l; By rotating it, it is confirmed that the recording paper passes, that is, the normal conveyance status.

That is, if the recording paper carried out from the paper feed cassette 50 still does not rotate the actuating piece 100 after a certain period of time, it is assumed that a jam has occurred and the conveyance operation is automatically stopped, and at the same time a warning is displayed externally. It's my turn to do that.

When the color toner image is synthesized on the photoreceptor drum IO, the paper feed shutter S is moved in synchronization with the image position of the toner image.
is retracted and the recording paper moves along the paper feed guide wheel, and the toner image is transferred to the recording paper while being held between it and the photosensitive drum IO by a transfer device 80# using a belt. , the recording paper is conveyed while being attached to the transfer belt 80C of the transfer device 80. Note that the transfer device 80 is spaced apart from the photoreceptor drum 10 while forming the toner image on the photoreceptor drum 10, and is controlled to be in a pressure contact state slightly prior to the time of transfer. .

A fixing device is located on the downstream side of the transfer device 80, and the recording paper of the image transfer flow conveyed by the transfer bell 80C fuses and fixes the toner image by a pair of fixing rollers 63, and then transfers the toner image to a pair of paper ejection rollers 64. It is fed to the upper part of the apparatus main body or to the left side discharge part.

FIG. 2 shows a perspective view of the paper feed sensor provided on the transport path. In FIG. 2, lOl is a shaft member 102 that penetrates the actuating piece 100 and supports it integrally.
is a contact piece fixed to one end of the shaft member 101, and therefore the actuation piece 100, the shaft member 101, and the contact piece 10 are connected to each other.
2 are integrated, and the bearing is supported between the front and rear side plates 103 of the main body of the apparatus via the shaft member 101, and the rotational moment due to its own weight abuts against the stopper 103A and keeps it stationary.

104 is a pair of upper and lower guide plates forming the paper feed guide 72; 104A is a groove portion, that is, an elongated hole provided at a position corresponding to the paper width center of each guide plate 104; and the actuating piece 100 is an elongated hole. 104A is inserted into the recording paper conveyance path and is biased to a position where the conveyance path of the recording paper is interrupted.

102A is a bent portion of the contact piece 102, and the side plate 1
The optical path of a photosensor 106, which is a paper feed sensor, is inserted through the elongated hole 103A of No. 03 and protruded from the back side of the side plate 103, and is directly connected to the printed circuit board 105 of the control section, thereby turning the photosensor 106 into an OFF state. Note that long hole 103
One end of A is a stopper portion 10 that limits the operation of the contact piece 102.
It is 3B.

When the recording paper that has passed through the paper feed guide 71 presses the operating piece 100 with its leading edge and rotates counterclockwise, the contact piece 102 is also rotated in the same direction via the shaft member lO1, turning on the photo sensor 106. Switch.

When the control section receives this signal, it is determined that the conveyance status of the recording paper is normal, and the conveyance operation is further continued.

On the other hand, even after a certain period of time has elapsed after the recording paper is unloaded from the paper feed cassette 50, the photo sensor 106 is still off.
If it remains in state F, it is determined that there is an abnormality in the conveyance of the recording paper, the conveyance operation is immediately stopped, and an instruction to remove the recording paper that cannot be conveyed is displayed.

In this embodiment, the paper feed sensor provided in the paper feed section has been described, but it is of course possible to provide the sensor in the paper discharge section. Further, the actuating piece 100 is biased clockwise using the rotational moment due to the weight of the contact piece 102.
Of course, it is also possible to configure the contact piece 102 or the actuating piece 100 to be biased by an elastic member such as a tension spring.

〔Effect of the invention〕

According to the present invention, it is possible to directly mount a paper feed sensor used in a copying machine, etc. on a control system board located at the back of the main body of the apparatus, and as a result, the layout of the support member of the paper feed sensor and the east line, and the accompanying Paper feed sensors for copying machines, etc., which require no additional work, have a simple configuration, and are easy to assemble can now be provided.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of an image forming apparatus equipped with a paper feed sensor of the present invention, and FIG. 2 is a perspective view of the main parts thereof. lO...Photosensitive drum 50...Paper feed cassette 61, (62)...First (second) paper feed roller 71.7
2...Paper feed guide 101...Shaft member 103...Side plate +05...Printed circuit board S...Shutter plate 100...Operating piece 102...Touch piece 104...Guide plate 106...・Photo sensor

Claims (1)

[Claims] A shaft member is provided below the guide plate at right angles to the conveying direction of the recording paper, and the shaft member is provided with an actuating piece and a contact piece that protrude from the groove portion provided in the guide plate. A sheet feeding sensor characterized in that when the actuating piece is pushed down and passed, the contact piece turns on/off a photosensor provided on a substrate.