JPS6347235A - Paper feeding unit of picture image forming device - Google Patents

Abstract

PURPOSE:To prevent an electric shock or an accident at the time of reusing a cassette or recharging said cassette into a picture image forming device by grounding a metal member such as a side restricting plate, etc. via a paper loading plate and a paper feeding cassette engaging device during the use of said cassette. CONSTITUTION:A paper loading plate 204 is mechanically and electrically connected to side restricting plates 207 by means of springs 208. Thereby, an electric charge which flows from the stack of sheets of paper into the side restricting plates 207, flows into ground through a grounding circuit after flowing the paper loading plate 204 via the springs 208, without causing the accumulation of charges on the side restricting plates 207. Accordingly, even if a paper feeding cassette in which sheets of paper which are left unused are contained is removed out of an engaging device and let alone, remarkable accumulation of charges does not occur on the side restricting plates and the paper loading plate in the cassette. Accordingly, the discharge of a large quantity of electric charge does not take place even if a person feels the cassette which is let alone by hands, or a discharge which adversely affects a picture image forming device does not take place when the cassette is recharged into the picture image forming device for the reuse of the cassette.

Description

Detailed Description of the Invention (Field of Application of the Invention) The present invention relates to a paper feeding device in an image forming apparatus such as an electrophotographic device, and more specifically, in a paper feeding device using a paper feeding cassette, The present invention relates to a paper feeding device configured to prevent the adverse effects of discharge on an image forming apparatus.

(Background of the Invention) As is well known, a paper feeding device installed in an image forming apparatus such as an electrophotographic device is a paper feeding device for storing sheets of paper for image recording in a stacked state. It consists of a cassette and a paper cassette locking device provided within the main body of the image forming apparatus to lock the paper cassette.

When the image forming apparatus starts operating with the paper feed cassette (hereinafter abbreviated as cassette) being locked in the paper feed cassette locking device (hereinafter abbreviated as cassette locking device), A paper feed roller in the image forming apparatus pulls out the topmost paper sheet of the paper stack (paper stack) in the cassette one by one and sends it to the image recording section (transfer section) in the image forming apparatus. The image is recorded on the paper.

In the above state, when the top sheet of the paper stack is pulled out of the cassette by the paper feed roller,
As the paper being pulled out and the paper immediately below it rub against each other, a heavy electrical charge is generated on the surfaces of both papers. When such a paper pull-out operation is repeated many times, a large amount of electric charge accumulates in the paper stack, and the metal side regulating plate that is close to or in contact with the paper stack also accumulates this electric charge. Static electricity is charged in response to this. The charge accumulated on the paper stack eventually flows into the metal paper stacking board on which the paper stack is placed. In this way, when using a cassette whose paper stacking plate is charged with static electricity, a metal pressure plate, which is a part of the paper feed cassette locking device, is pressed against the paper stacking plate. Therefore, the accumulated charge on the paper stacking plate flows into each part of the image forming apparatus via the pressure plate and is then discharged to the ground through the ground wire provided in the image forming apparatus. Since other metal members such as the side regulating plates inside the cassette are not electrically connected to the paper stacking plate, static electricity is accumulated on the side regulating plates even while the cassette is in use.

After using the cassette as described above, if the cassette is removed from the image forming apparatus with a considerable amount of unused paper left in the cassette, the paper loading plate and side guide plate inside the cassette will be damaged. Since there is no place for the accumulated charges to escape, the cassette is left charged to a high potential. Therefore, when a person touches the cassette with a finger, a high potential discharge occurs, giving a considerable discharge shock to the finger, or when the cassette is reinstalled in the image forming apparatus for reuse. Sometimes, a large amount of charge is instantaneously released from the cassette to the image forming apparatus, resulting in problems such as adverse effects on control circuits and the like within the image forming apparatus.

Conventionally, the above-mentioned discharge of charges that occurs when a cassette is reinstalled into an image forming apparatus did not have a major adverse effect on the operation of the image forming apparatus, but in recent image forming apparatuses, as a control device. Since ICs, microcomputers, etc. that operate on weak currents and voltages are installed, if a large amount of charge is released from the paper feed cassette as described above, noise due to the charge release will be generated in the IT equipment. If this happens, malfunctions may occur, and as a result, there is a risk that the image forming apparatus may not be able to exhibit its expected performance.

Therefore, the present inventor has invented a paper feeding device that can suppress sudden discharge from a cassette when the cassette is reinstalled into an image forming apparatus, and has filed a patent application for this paper feeding device separately from this application. However, because the paper feeding device was structured so that the side regulating plates and other members were not grounded while the cassette was in use, electric charges continued to accumulate on the side regulating plates, etc. even while the cassette was in use, resulting in injury to people. An object of the present invention is to eliminate the risk of electric shock to a person's hands and fingers when reusing a paper feed cassette, and to prevent electric shock from occurring when the cassette is reinstalled in an image forming apparatus. It is an object of the present invention to provide a paper feeding device which does not adversely affect a control device of an image forming apparatus due to discharge from a cassette.

(Summary of the Invention) The paper feeding device of the present invention includes a conductive paper stacking plate provided in a paper feeding cassette so as to be movable up and down, and a paper feeding cassette locking device provided in the paper feeding cassette to engage with the paper stacking plate. a conductive pressure plate,
a grounding means for directly or indirectly grounding the pressure plate;
This constitutes a grounding circuit for the paper feed cassette, while a metal member provided in contact with or close to the paper in the paper feed cassette is constantly electrically connected to the paper stacking board via a conductive elastic member. It is characterized by being connected. In the paper feeding device of the present invention, the metal members such as the side regulating plates inside the paper feeding cassette are grounded via the paper stacking plate and the paper feeding cassette locking device while the cassette is in use. Electric charge does not accumulate on the metal member during use of the cassette, and therefore, even if a person touches the metal member with a finger when reusing the cassette, a large discharge will not occur, and therefore, the user will not receive an electric shock. Never.

(Example of the invention) The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a perspective view of a paper feed cassette 2 constituting the paper feed device of the present invention, and FIG. 2 shows a perspective view of a paper feed cassette locking device that also constitutes the paper feed device of the present invention. .

The paper feed cassette locking device 1 shown in FIG. 2 is composed of various members described below. That is, a pair of bearing members 101 are fixed in the housing of the image forming apparatus, and a rotation shaft 10 is rotatably supported at both ends by the bearing members 101.
2. A locking lever 103 fixed to both ends of the rotation shaft 102 to lock a paper feed cassette 2, which will be described later, and the rotation shaft 1.
02, a pressure plate 104 is provided with a pair of support parts 104a that are loosely fitted to the rotation shaft 10, and is supported so as to be rotatable relative to the rotation shaft 102 via the support parts 104a.
A coil spring 105 has one end locked to the hook 104b of the pressure plate 104 and the other end engaged with the hook 104b of the pressure plate 104. The paper feed cassette locking device 1 is constituted by various members such as a grounding means 106 which electrically grounds the pressure plate 104 via the paper feed cassette locking device 1 .

The locking lever 103, which can rotate integrally with the rotation ith 102, has a tip protrusion 103a that fits into a side edge recess of the paper feed cassette 2, which will be described later. A first stopper 101a is provided on the bearing member 101 that rotatably supports the rotation shaft 102 so that the locking lever 103 stands still at a predetermined inclination angle, and the paper feed cassette 2 is When the locking lever 103 is pulled out from the locking device 1, the locking lever 103 remains stationary at a position where it is pressed against the stopper 101a.

A bottle 102a is protruded from the outer peripheral surface of the rotation shaft 102, and the rotation! A hook 105a at one end of the coil spring 105 fitted to the 1th O2 is engaged with the bottle 102a, and an engaging portion 105b at the other end of the coil spring 105 is engaged with a hook 104b erected on the pressure plate 104. It is designed to engage and hang.

When the paper feed cassette 2 is not inserted into the locking device 1, the coil spring 105 biases the rotating shaft 102 in the clockwise direction, and the hook 104b of the pressure plate 104 is attached to the engaging portion of the coil spring 105. It receives an upward force from 105b.

Another bottle 102b is protruded from the outer circumferential surface of the rotating @102, and the bottle 102b is attached to the pressurizing plate 1 in the state shown in FIG.
04 is pressed against a second stopper 10=4c erected. A curved protrusion 104d is provided at the tip of the pressure plate 104 to engage with a paper stacking plate in a paper feed cassette, which will be described later.

On the other hand, the paper feed cassette 2 includes a front plate 201 having an opening 201a in the center, a bottom plate 202 having an opening 202a (see FIG. 3) connected to the opening 201a in the front end, and a locking lever. Inclined surface 2 that engages with the tip of 103
03a on the front side and a recess 203b on the upper surface near the front end into which the tip protrusion 103a of the locking lever 103 fits; and a rear plate connecting the rear ends of the side plates 203. 205, opening 2 of the bottom plate 202
A paper stacking plate 204 that covers the bottom plate 1202a and can be moved up and down on the bottom plate 1202 is provided. The paper stacking board 204 is made of metal,
It is pivotally connected to the side plate 203 by a pin 206 at its rear end.

As explained in FIGS. 3 and 4, the opening 201a formed in the center of the front plate 201 allows the paper feed roller 3 disposed inside the casing of the image forming apparatus to be inserted into the paper feed cassette 2. This is an opening for the paper feed roller to enter into.

In addition, an opening 202 formed at the center of the front end of the bottom plate 202
A is a pressure plate entry opening for allowing the pressure plate 104 of the paper feed cassette locking device 1 to enter into the paper feed cassette 2.

In addition, 209 is a paper stacking plate 20 to prevent double feeding of the final paper.
This is a separation sheet provided on 4.

Inside the side plate 203 , a metal side regulating plate 207 parallel to the side plate 203 is erected on the bottom plate 202 . The side regulating plate 207 is for vertically aligning the side edges of the papers stacked on the paper stacking plate 204, and a window 207a is provided through the side regulating plate 207 approximately at the center thereof. Further, a lateral protruding piece 204a having a width narrower than the width of the word meaning 207a is protruded from the side garland of the paper stacking plate 204, and the lateral protruding piece 204a projects to the outside of the side regulating plate 207 through the word meaning 207a. ing. A locking portion 204b rising upward is provided at the tip of the side projecting piece 204a, and the locking portion 204b and the side regulating plate 20
As another locking portion 207b protruding from the rear end of 7, a gold or faux metal spring 208 is stretched.

The window 207a of the side regulating plate serves as a stopper that determines the upper limit of the vertical movement of the paper stacking plate 204, and the side protruding piece 2
04a comes into contact with the upper edge of the window 207a, the paper loading plate 20
4 is stopped at the highest position.

Figures 3 and S4 show the paper feed cassette 2 having the structure as shown in Figure 1.
is attached to the paper feed cassette locking device 1 shown in Fig. 2 to show the completed state as a paper feed device, and Fig. 3 shows a state in which a considerable amount of paper P is still loaded in the paper feed cassette 2. FIG. 4 shows a state when the amount of paper P in the paper feed cassette 2 is running low.

When attaching the paper cassette 2 to the paper cassette locking device 1, when the paper cassette 2 is propelled forward toward the paper cassette locking device 1, the tip of the locking lever 103 first touches the cassette. The inclined surface 20 at the front end of the side plate 203 of No. 2
3a, the protrusion 104 at the tip of the pressure plate 104 passes through the opening 202a of the bottom plate 202 of the cassette 2.
d enters the cassette, and the protrusion 104d comes into contact with the lower surface of the paper stacking plate 204.

Further, the paper feed roller 3 enters the opening 201a of the front plate 201 of the cassette 2. When the cassette 2 is further propelled forward in this state, the tip of the locking lever 103 moves upward 8 times along the inclined surface 203a, and finally rises to the top surface of the side plate 203 of the cassette. As shown in FIG. 3, the distal end protrusion 103a of the locking lever 103 falls into the recess 203b on the top surface of the side plate 203 and is locked therein. During this process, the spring 105 is returned to its original position, so that the pressure plate 104 applies a counterclockwise torque to the spring 10 in FIG.
As a result, the paper loading plate 204 is
, and the paper P on the paper stacking plate 204 is pressed toward the outer peripheral surface of the paper feed roller 3 .

When the image forming apparatus starts to move in the state shown in FIG. In FIG. 3, it is pulled out to the left and supplied to the image forming section (that is, the transfer section). During this paper drawing process, static electricity is generated in the cassette 2 due to the friction of the paper, and static electricity accumulates on the paper stack, but the side regulating plate 207 and paper stacking plate 204 that are in contact with the paper stack are The static electricity flows into the paper stacking plate 204 and the side regulating plate 207 because the paper is made of a conductive material.

By the way, when the paper feed cassette 2 is locked in the paper feed cassette locking device 1, as shown in FIGS. 3 and 4, the grounding means 106 provided in the locking device 1 rotates tM 1.
02, the pressure plate 104, and the paper stacking plate 204 form a grounding circuit, so that the electric charge flowing into the paper stacking plate 204 flows to the ground through the grounding circuit.
No charge accumulation occurs on the paper stacking board 204. Also,
In the paper feeding device of the present invention, the paper stacking plate 204 and the site regulation plate 207 are mechanically and electrically connected by the spring 208, so that the electric charge flowing into the side regulation plate 207 from the paper stack also flows through the spring 208. After flowing through the paper stacking plate 204, it flows into the earth through the grounding circuit, so that no charge is accumulated on the side regulating plate 207. Therefore,
In the paper feeding device of the present invention, even if the paper feeding cassette containing unused paper is removed from the locking device and left unattended, significant charge accumulation will not occur on the side regulating plate or paper stacking plate inside the cassette. Therefore, even if a person touches the cassette after it has been left unused, a large amount of electric charge will not be discharged, and even if the cassette is reinstalled into the image forming apparatus for reuse, there will be no harm to the image forming apparatus. No discharge occurs.

FIG. 4 is a diagram showing a state in which the amount of paper P in the cassette 2 is decreasing while the paper feeding device is in use. As the paper pvi in the cassette 2 decreases, the paper stacking plate 204
The front end of is pushed up by the pressure plate 104 and the paper stacking plate 204 is rotated upwards around the bin 206, so that the paper P on the paper stacking plate 204 can be fed even if the amount of paper is small. It will be pressed against the circumferential surface of the paper roller 3 with the same force. Also, even if the paper is reduced like this, the spring 20
8 maintains the electrical connection between the paper stacking plate 204 and the side regulating plate 207, so that an increase in charge accumulation in the cassette 2 is prevented regardless of the amount of paper remaining in the cassette 2. Ru.

FIG. 5 shows another embodiment for electrically connecting the ± side regulating plate 207 and the paper stacking plate 204. In this embodiment, the side regulating plate 207 is replaced with the spring 208 described above. A leaf spring 210 fastened on the mounting bottom plate part 207c of the fifth plate is used as an electrical connection member between the side regulating plate 207 and the paper stacking plate 204.
As shown in Figure (a), it is provided so as to rise slightly diagonally upward at a position outside the side regulating plate 207 and corresponding to the window 207a. Also,
The side protruding piece 204a of the paper stacking plate 204 is the root spring 210.
It is designed to move up and down while sliding in contact with the
Even when the paper stacking plate 204 moves up and down, electrical connection is always maintained between the paper stacking plate 204 and the side regulating plate 207.

FIG. 6b shows still another embodiment regarding the electrical connection between the side regulating plate 207 and the paper stacking plate 204. In this embodiment, a conductive brush 211 bonded to the outer surface of the side regulating plate 207 with a conductive adhesive tape is used in place of the leaf spring 210 shown in FIG. Further, the ring 7 brush 211 is attached to the side projecting piece 204a of the paper stacking board 204.
A vertical piece 204c is formed which makes surface contact with. Since the conductive brush 211 faces the window 207a of the side regulating plate 207 and extends vertically upward, even when the paper stacking board 204 moves up and down, the vertical piece 204c slides against the conductive brush 211 and moves up and down. Therefore, the side regulation plate 207 and the paper loading plate 204
The electrical connection with the cassette is maintained regardless of the amount of paper in the cassette.

In each of the above embodiments, a spring or a mutually sliding member is used as a member to maintain electrical connection between the paper fJIt loading plate and the side regulating plate, but the difference between the paper loading plate and the side regulating plate is Of course, a normal cord connection may be used as a means for maintaining mutual electrical connection.

(Effects of the Invention) As explained above, in the paper feeding device of the present invention, since the side regulating plate inside the paper feeding cassette is grounded while the paper feeding device is in use, a large amount of electric charge is accumulated in the paper feeding cassette. does not occur,
Therefore, even if the cassette is touched after being removed from the image forming apparatus and left unattended, a discharge shock due to the release of a large amount of accumulated charge will not occur.

Furthermore, in the paper feeding device of the present invention, even when the paper feeding cassette is reinstalled in the image forming device, a harmful amount of static electricity is not released to the image forming device, so that malfunctions of the image forming device can be avoided. There is no risk of causing an accident.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a first embodiment of a paper feed cassette, which is the main component of the paper feed device of the present invention, and FIG. 2 is a perspective view of the paper feed cassette, which is another component of the paper feed device of the present invention. A perspective view of the device; FIGS. 3 and 4 are side sectional views of the main parts of the paper feeding device of the present invention, which is a combination of the paper feeding cassette of FIG. 1 and the paper feeding cassette locking device of FIG. 2; FIG. 5 is a diagram showing another embodiment of the present invention regarding the structure inside the paper feed cassette.
) is a partial side sectional view of the paper feed cassette, and FIG.
FIG. 6 is a plan view of a part of FIG. 6A, and FIG.
6(a) is a partial side sectional view of the paper feed cassette, and FIG. 6(b) is a partial plan view of FIG. 6(a). 1...Paper cassette locking device 2 paper cassette 3.
...Paper feed roller 101...Bearing is member 102
... Rotating shaft 103 ... Locking lever 104
... Pressure plate 105 ... Spring 106 ...
Grounding means 201...Front plate 202...Bottom plate 203...Side plate 204...Paper loading board 207...Side regulating plate 208...Spring
210... Leaf spring 211... Conductive brush.

Claims (1)

[Scope of Claims] 1. An image forming apparatus comprising a paper feed cassette locking device built into the main body of the image forming apparatus, and a paper feed cassette detachably locked to the paper feed cassette locking device. In the paper feeding device, a conductive paper stacking plate provided in the paper feeding cassette so as to be movable up and down, and a conductive pressure plate in the paper feeding cassette locking device that engages with the paper stacking plate; A grounding circuit for the paper cassette is constituted by a grounded paper feeding means in the paper cassette locking device of the paper cassette, which directly or indirectly grounds the pressure plate; Paper feed for an image forming apparatus, characterized in that a conductive member close to the paper and a conductive member in direct contact with the paper are electrically connected to the paper stacking plate via a conductive elastic member. Device. 2. In claim 1, the paper stacking plate is supported within the paper feed cassette so as to be able to swing vertically about an axis that is perpendicular to and horizontal to the paper transport direction. A paper feeding device for an image forming apparatus characterized by: 3. In claim 1, the conductive member is
A paper feeding device for an image forming apparatus, comprising a side regulating plate for aligning both side edges of paper within the paper feeding cassette.