JP2003089438A - Paper feed cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the double feeding caused by charged paper by easily eliminating static electricity generated by the oscillation of the paper in feeding out the paper from a paper feed cassette. SOLUTION: A conductive member 40 is mounted on a hinge part 31 to a bottom plate 30 supporting the paper inside of the paper feed cassette 20, and is projected to an outer face of a paper feed cassette frame 21a to be connected to a plate spring. A frame 15a of a paper feed part 15 of the image forming device is provided with a plate spring 42 connected to a metallic frame, and the contact points 41, 42 of both springs are elastically abutted on each other to eliminate the static electricity charged on the bottom plate, when the paper feed cassette 20 is loaded.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for feeding static electricity generated by sliding of paper sheets to a ground of a main body of the apparatus through a bottom plate when feeding paper sheets from a paper cassette. The present invention relates to a sheet feeding cassette for releasing a sheet to be fed so as not to be affected by static electricity. 2. Description of the Related Art Generally, in an image forming apparatus for forming an image on a sheet, such as an electrophotographic copying machine or a facsimile machine, a sheet cassette for accommodating sheets of an arbitrary size is arranged in a sheet feeding section. are doing. Inside the paper cassette,
A large number of sheets are stacked and stored on the bottom plate, and the sheets are separated one by one using a sheet feeding roller of a sheet feeding device provided in a sheet feeding unit and a sheet separating unit such as a separation claw. It is sent to the image recording unit. A regulating member such as a side guide or an end guide is provided in the sheet accommodating portion of the sheet cassette in order to regulate a rear end portion and a side surface in the sheet feeding direction, and sheets are set in the sheet accommodating device. Later, the regulating member is moved to regulate the rear end portion and the side surface of the sheet, so that the sheet is not displaced and both corners of the sheet are not separated from the separation claw. And when sending out paper from the paper cassette,
The corners on both sides of the leading end portion of the sheet on the sending side are locked by separating claws, and only one sheet is separated and fed by the feeding force of the sheet feeding roller and the resistance action (at the hook portion) by the separating claw. Make the action possible. When the paper is fed from the paper cassette, the paper is pressed against the paper feed roller by a pushing action of an elastic member for urging the bottom plate upward. In this state, the fed sheet is conveyed while being rubbed against the remaining sheet.
However, when the paper is rubbed, static electricity is generated between the papers, and when the electrostatically charged paper is transported in the paper transport path of the image forming apparatus, the static electricity is applied to other members of the image forming apparatus. Inconveniences, such as flowing, may cause trouble in image formation. Also, when the remaining amount of paper stored in the paper cassette becomes small, static electricity generated by the paper rubbing on the top surface of the paper is accumulated on the paper and the bottom plate, and two sheets of paper are simultaneously caused by the static electricity. There is a problem that so-called double feed occurs. Therefore, it is conceivable to remove the static electricity accumulated on the paper or the bottom plate using a ground,
If the ground is directly connected to a paper cassette detachably provided to the image forming apparatus, the ground may be disconnected due to an impact generated at the time of attachment and detachment. The present invention solves the above-mentioned problem of the static electricity of the paper feed cassette, and provides a paper feed cassette which can be easily connected from the bottom plate of the paper feed cassette to the ground of the apparatus main body. It is intended to be. [0005] The present invention relates to a sheet feeding cassette for storing sheets of paper, mounted in a sheet feeding section of an image forming apparatus main body, and feeding sheets of paper. The present invention is characterized in that a conductive elastic body is brought into contact with a mounting piece of a bottom plate, on which a sheet is placed, which is housed in a housing of the paper feed cassette, and the elastic body connects the paper feed cassette to a paper feed unit. When stored in the device body, it comes into contact with a leaf spring provided on a frame of the apparatus main body. [0006] With the above configuration, the conductive member connected to the metal bottom plate can be elastically and easily brought into contact with the leaf spring provided in the sheet feeding section of the image forming apparatus. The contact state of the ground member can be set well. Since the static electricity accumulated on the bottom plate of the sheet cassette can be discharged to the ground via the frame of the sheet feeding section, it is possible to prevent the occurrence of inconvenience due to the charging of the fed sheet. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A paper cassette according to the present invention will be described with reference to the illustrated example. The paper cassette 20
1 is configured as shown in the plan view of FIG. 1 and the side view of FIG. 2, and is configured as a so-called universal type paper feed cassette capable of storing paper of an arbitrary size in the paper storage unit 25. You. The paper feed cassette 20 has a direction X in which paper is fed out at a right angle to a direction Y in which the paper feed unit is mounted on the paper feed unit of the image forming apparatus. A pair of leg members 24, 24a on both sides are provided on the front side of the mounting side so as to protrude,
When detaching from the paper feed unit of the image forming apparatus,
A guide member provided with a paper feed unit 4 and 24a (not shown)
Let me guide you. A bottom plate 30 made of a conductive metal is swingably provided in a sheet accommodating portion 25 of the sheet feeding cassette 20 via hinge portions 31 and 31a as attachment pieces. It is set on the bottom plate 30 so that the front plate 22 disposed at the front end in the sheet feeding direction X can be raised significantly. In order to regulate the sheets to be accommodated in the sheet accommodating section 25, there are provided an end guide 32 for pressing the rear end portion of the sheet on the sending side, and side guides 33 and 34 for regulating both sides of the sheet. The three guide members 32 to 34 are provided so as to be guided along guide members 27, 28, and 28a provided on the bottom plate 26 of the housing 21, and the guide members can be fixed at arbitrary positions. It is assumed. Further, in a center-registration type paper feed cassette that sets the paper feed center with respect to the center of the paper feed cassette, side guides 33 and 34 for regulating both sides of the paper are arranged along the bottom plate 36. The two side guides 33 and 34 are provided so as to be able to be separated from each other by using an interlocking mechanism. The two side guides 33 and 34 include:
Separating claws 35 and 35a are supported, respectively. In the example of the side guide 33 and the separating claws 35, as shown in detail in FIG. 2, an end of a support stay 36 provided with the separating claws 35 is hinged. 37 is provided so as to be rotatable. The support stay 36 and the separating claw 35 are formed by bending a sheet metal, and a greatly curved portion is disposed below the bottom plate 30 so that the swing of the bottom plate 30 is not hindered. I do. In addition, the separation claw 35
In the same manner as that generally used in the related art, a substantially triangular flat claw is locked and held at the corners on both sides in the sheet feeding direction, and the feeding force of the paper feed roller and the separation claw 35 are held.
Thus, the sheet separating function can be exhibited. In the paper feed cassette 20, as shown in FIG. 3, a leaf spring 40 made of conductive metal is provided on a hinge portion 31 of the bottom plate 30, and the leaf spring 40 is connected to the bottom plate 30. Always contact The leaf spring 40 penetrates through the side plate 21a of the housing 21 of the sheet cassette 20 and is exposed on the outer surface of the side plate. The leaf spring 40 is configured as a contact point by a leaf spring member 41 disposed at the exposed portion. . In the paper feeding section of the image forming apparatus to which the paper feeding cassette 20 is mounted, a leaf spring 42 made of conductive metal is provided so as to protrude from the inner surface of the side frame 15a. And the metal frame of the frame is connected to ground by a conventionally known grounding means. The paper cassette is mounted on the paper feeding section of the image forming apparatus, so that the paper
The plate spring 41 of this embodiment is brought into contact with the plate spring of the sheet feeding section frame so that the static electricity of the bottom plate can flow to the ground. Each time the sheet cassette 20 is attached to or detached from the sheet feeding unit, the contacts 41 and 42 formed by leaf springs provided on the frame 15 of the sheet feeding unit 20 and the apparatus sheet feeding unit are in good condition by the elasticity of the springs. Since it can be brought into contact, the contact state does not deteriorate due to aging. When the grounding means of the bottom plate 30 is used, even if static electricity is generated due to friction of the paper fed from the paper feed cassette, the static electricity is grounded through the conductive bottom plate 30. In addition, adverse effects due to charging of the fed paper can be avoided. The paper cassette 20 constructed as described above
In setting the paper in the paper storage unit 25,
The paper P is placed with the bottom plate pressed down.
Then, when the side guides 33 and 34 are moved so as to be close to each other and positioned while pressing the side surface of the sheet P,
The separation claws 35 and 35a stop at a position corresponding to the corner of the leading end of the sheet P on the sending side. In order to lock and hold the bottom plate 30 at the lowered position, a locking and holding means similar to that provided in a conventional sheet cassette can be provided. The locking and holding means is configured so that the locking and holding with respect to the bottom plate 30 is released at the final stage of the operation of inserting the paper cassette 20 into the paper feeding section of the image forming apparatus. As described above, the side guide 33,
When the sheet feeding cassette is mounted on the sheet feeding unit in a state where the sheet 34 is positioned on both sides of the sheet P, the locking of the bottom plate 30 is released, and the operation of raising the sheet P together with the bottom plate 30 is performed. When the bottom plate 30 is raised, the upper corner portion of the paper P is locked by the separation claw 35, and is raised together with the paper P to a position where the paper P can be fed at a position corresponding to the paper feed roller 16. Stop. Each time the paper feed roller 16 is rotated in a state where the corners of the paper rising to the paper feed position are locked by the separation claw 35, the paper is separated one by one from the top of the paper. This makes it possible to feed paper toward the paper transport path of the image forming apparatus. Paper feed cassette 2 configured as described above
No. 0 can be mounted on the image forming apparatus configured as shown in FIG. The image forming apparatus 1 includes a recording unit 2 and a sheet feeding unit 1 in which a sheet feeding cassette 20 is mounted.
5 is provided as an example, but a plurality of paper feed cassettes can be mounted on the paper feed unit 15. When one or a plurality of other paper cassettes can be additionally provided below the illustrated paper cassette 20, a cassette mounting portion and a paper feeding device are additionally provided, and each paper cassette is provided. The paper sent from the paper cassette is passed through guideway 1
8 can be fed vertically by connecting them vertically. In the recording section 2 of the image forming apparatus 1, a charging member 4, a writing member 5, and a developing roller 7 are provided around a photosensitive drum 3 on which a toner image is formed in accordance with the rotation direction. Developing device 6 arranged corresponding to drum 3
Are provided. Further, a transfer roller 8 is disposed with the sheet conveyance path 10 interposed therebetween, and a voltage of a predetermined value is applied from the back side of the sheet passing through the sheet conveyance path 10 to transfer the toner image formed on the photosensitive drum 3. The charging member 4
A brush member 9 for disturbing the toner memory and weakening the adhesion of the toner is disposed in the upstream part of the brush member. A paper transport path 10 is provided for transporting the paper inside the recording section 2, and the paper is transported by a transport roller device 12 in synchronization with the toner image formed on the photosensitive drum 3. I do. Further, in the paper transport path 10, a paper feed cassette 20 set in the paper feed section 15 is provided.
Then, the paper fed by the paper feed roller 16 is guided toward the paper transport path using the paper guide 17, and is transported by the transport roller device 11 to the transport roller device 12. Then, the transport roller device 12 is driven in synchronization with the toner image formed on the photosensitive drum 3, and the toner image is transferred between the photosensitive drum 3 and the transfer roller 8. In the recording section 2, the photosensitive drum 3 is charged uniformly by a charging member 4 on the surface of the drum, and is then irradiated with image light from a writing member 5 to form an electrostatic latent image. Is formed, and toner is supplied from the developing roller 7 to the electrostatic latent image, thereby visualizing the electrostatic latent image as a toner image. The toner image is transferred from the photosensitive drum 3 toward the paper by applying a predetermined voltage from the back side of the paper, and the paper carrying the toner image is fixed through the fixing device 13. The sheet is discharged by a discharge roller device 14 to a discharge section provided on the upper surface of the sheet feeding section 15. In the paper supply section 15, a paper supply roller 16 is disposed above the paper supply side of the paper supply cassette. In a paper supply cassette mounting section, a guide member 19 used for attaching and detaching the paper supply cassette is provided. , 19a. Then, the leg members 24, 24a provided on the housing of the paper feed cassette and guided members (not shown) formed on both sides of the housing are slid on the guide members 19, 19a to feed the paper. The operation of attaching and detaching the cassette is performed. Further, in a state where the paper cassette 20 is pushed in and stopped, the bottom plate 30 is raised, and the upper surface of the paper is pressed against the paper feed roller 16,
Try to deal with the paper feeding operation. Note that a vertical guide path 18 is formed in the frame on the paper feed side of the paper feed unit 15. For example, a plurality of paper feed cassette housing mechanisms similar to the paper feed unit 15 are arranged so as to be vertically stacked. In this case, the paper supplied from the lower paper feed cassette can be transported to the paper transport path 10 of the recording unit via the vertical guide path 18. In the embodiment of the present invention, the image forming apparatus in which the sheet cassette is mounted on the sheet feeding section is, of course, applied to an image forming apparatus for forming a toner image using an electrophotographic system. The present invention can be applied to an apparatus that records an image using cut paper or sheets, such as a facsimile apparatus and a printer. In addition, in the case where a contact for discharging static electricity is provided in the same sheet accommodating means as the above-mentioned sheet feeding cassette by exposing the contact, an auxiliary means for releasing static electricity generated on the sheet can be provided. Not something. Further, of the two contacts provided on the sheet cassette and the main body frame, the contact on the sheet cassette side can be made of any member as long as it can exert a pressing action on the leaf spring on the body side. is there. According to the above-described structure, the conductive member connected to the metal bottom plate can be elastically and easily attached to the leaf spring provided in the sheet feeding section of the image forming apparatus. Contact can be made, and the contact state of the ground member can be set well. Since the static electricity accumulated on the bottom plate of the sheet cassette can be discharged to the ground via the frame of the sheet feeding section, it is possible to prevent the occurrence of inconvenience due to the charging of the fed sheet.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a paper feed cassette. FIG. 2 is a side view of a paper feed cassette. FIG. 3 is an explanatory view of a member for grounding static electricity. FIG. 4 is an explanatory diagram illustrating a configuration of an image forming apparatus. [Description of Signs] 1 image forming apparatus, 2 recording unit, 3 photoconductor drum, 4 charging member, 5 writing member, 6
Developing device, 7 developing roller, 8 transfer roller,
10 paper transport path, 11 and 12 transport roller device,
13 fixing device, 14 discharge roller device, 15
Paper feeder, 15a body frame, 16 paper feed roller, 17 paper guide, 18 guideway, 1
9 cassette guide, 20 paper cassette, 2
1 housing, 23 handles, 24 leg members,
25 paper storage unit, 26 bottom plate, 27/28
Guide, 30 bottom plate, 31 hinge,
32 End guide, 33/34 Side guide, 35 Separation claw, 36 Support stay, 37
Hinge, 40-42 leaf spring.

Claims (1)

Claims 1. A paper feed cassette for storing paper, mounted on a paper feed unit of an image forming apparatus main body, and feeding paper, wherein the paper is stored in a housing of the paper feed cassette, and A conductive elastic body is kept in contact with the mounting piece of the bottom plate on which the paper cassette is placed.
A sheet cassette, wherein the sheet cassette comes into contact with a leaf spring provided on a frame of the apparatus main body.