JP2514520Y2 - Paper feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a sheet feeding device that feeds sheets one by one in a posture, and is used, for example, to feed a document sheet onto a platen of an image forming apparatus.

[Prior Art] In a conventional sheet feeding device, in which a registration roller and a conveying unit are driven by a single driving unit, and a clutch unit for separating from the conveying unit is provided on the registration roller side, a sheet is abutted against the registration roller. At this time, in order to bring the registration roller into a stopped state, the clutch means is simply brought into a disengaged state and separated from the driving means.

[Problems to be Solved by the Invention] However, in the conventional paper feeding device in which the clutch means is simply disengaged in order to stop the registration roller, the registration roller has a slight friction resistance in its bearing and the roller itself. The registration roller rotates when the sheet hits, the sheet bites between the rollers, and the sheet moves along with the movement of the conveyance section, and the sheet is accurately corrected by the registration roller. There was a problem that I could not do it.

[Object of the Invention] The present invention has been made in view of the above-mentioned problems in the conventional sheet feeding device, and it is possible to perform the registration without changing the basic arrangement of the conveying unit, the registration rollers, and the common driving means of these. An object of the present invention is to provide a sheet feeding device that can always correct the posture of a sheet without the rotation of the registration roller and the biting of the sheet between the rollers when the sheet hits the roller.

[Means for Solving the Problem] The gist of the present invention for achieving the above-mentioned object is to separate a sheet one by one and to separate the sheets into a loop by abutting the tips of the separated sheets. The registration roller for feeding the sheet after the posture is corrected and the sheet is conveyed from the registration roller and has a single driving means for driving the conveyance section and the registration roller. A sheet feeding apparatus having a clutch means for separating a roller from the conveying section, the sheet feeding apparatus having a control means for stopping the driving means and bringing the clutch means into an engaged state when a sheet is abutted against the registration roller. ,.

[Operation] The stacked sheets are separated into one sheet by the separating means, the posture and timing of the sheets are adjusted by the registration rollers, and then the sheets are sent to the transport unit and discharged after necessary processing.

When the sheet hits the registration roller, the registration roller is in a stopped state, the leading edge of the sheet remains in contact with the registration roller, the rear portion continues the feeding state by the separating means, and the sheet draws a large loop to adjust the posture. Done.

Then, when the registration roller stops, the driving means also stops, and at the same time, the clutch means becomes the engaged state,
The registration roller and the transport unit are joined together. In other words, the registration roller stops not only with its own inertial resistance but also with a heavy load on the conveyance section on its back, and even if a hard sheet of paper quality hits it, the registration roller does not rotate, so that the posture of the sheet cannot be adjusted. Not disturbed.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the sheet feeding device 10 includes a document tray 11 on which a document sheet is placed, a sheet feeding section 20 which is a separating means for separating the document sheet from the document tray 11 into one sheet, and feeding the sheet. Receive the original from this paper feed section 20 and make it abut against the tip,
Registration rollers 26 and 27 that correct the posture of the sheet and feed timing by drawing a large loop on the rear part, and receive the original sheet from the registration rollers 26 and 27, and localize and expose it on the platen P of the image forming apparatus. Transport unit that receives processing
30, an ejection section 40 for ejecting exposed originals, and an ejection tray 12 for accumulating ejected originals.

The paper feed unit 20 picks up the pickup roller 21 in contact with the lowermost paper sheet, the weight leaf spring 23 in contact with the uppermost paper sheet, presses the leading edge of the original document 22 to open / close at a proper time, and separates only the lowermost paper sheet for feeding. It is composed of a separation roller 24, a separation pad 25 for preventing the progress of the second paper or more, and the like.

As shown in FIGS. 1 and 2, a registration space 15 surrounded by an outer guide plate 13 and an inner guide plate 14 is formed below the paper feeding section 20, and reaches a next registration roller 26, 27. A registration sensor 28 is provided in the narrow space for temporarily stopping the sheet and determining the sheet size and the trailing edge stop reference.

Below the registration sensor 28, registration rollers 26 and 27 for catching the leading edge of the original sheet and adjusting the posture to adjust the sheet feeding timing are arranged. A sheet guide 16 for guiding is installed.

The inner and outer guide plates 13 and 14 and the sheet guide 16
In this embodiment, is made of conductive synthetic resin.

The reason is that the original sheets are stacked on the original tray 11 and are pulled out from this stacked state through contact and sliding with the pickup roller 21, the separation roller 24, the separation pad 25, etc. Since it may be charged with a considerable amount of static electricity, if it is sent onto the platen P in this charged state, it will be adsorbed by the platen glass and it will not be possible to carry it accurately, so such internal and external guides made of a conductive material in advance. This is to remove the surface charges by contacting the plates 13 and 14 and the sheet guide 16.

Depending on the paper quality of the original, non-conductive material may be adsorbed on the wall surface of the sheet guide 16 or the like to make it impossible to feed the paper. However, by using a conductive material, such a thing is also prevented. be able to.

As such a conductive material, a resin material and a thin metal wire may be laminated, but a material in which the resin material itself has conductivity is advantageous from the viewpoint of moldability.

The conveying unit 30 is provided with a pair of belt rollers 32, 33 on a side plate 31 of the sheet feeding device 10, and a wide conveying belt 34, which is an elastic material, is wound around the belt rollers 32, 33 and stretched. It is equipped with a press roller 35.

The paper discharge unit 40 switches a paper discharge guide 41 that guides the document sheet around the reversing roller 42 that sends the document sheet, and discharges the document sheet or reversely sends it back onto the platen P for backside exposure. The switching claw 43, a reverse feed guide 44 for guiding the reverse feed original sheet, a sheet discharge sensor 45, a sheet discharge roller 46 for discharging the original sheet to the outside, and the like.

The paper feeding unit 20 is driven by a drive motor MT1, and the registration rollers 26, 27, the transport unit 30, and the paper discharge unit 40 are driven by a drive motor MT2 which is a single driving unit. . Then, on the registration roller 26 side, clutch means 60 for disconnecting from the transport unit 30 is provided.

 FIG. 3 shows a drive system of the drive motor MT2.

The power of the drive motor MT2 is transmitted from the output shaft pulley 51 to the gear 52, and the gear 52 is transmitted to the gear 53 fixed to the belt roller shaft 33a to drive the conveyor belt 34.

The gear 53 also meshes with the gear 54 and is transmitted from the coaxial pulley 55 through the toothed belt 56 to the pulley 57 and further to the coaxial gear 58. The gear 58 is the shaft 26 of the registration roller 26.
It meshes with a gear 59 provided coaxially with a.

Thus, the gear 59 has clutch means as shown in the drawing.
60 is provided so that the registration roller shaft 26 and the gear 59 can be engaged and disengaged at appropriate times. The clutch means 60 is composed of an electromagnetic clutch, and is engaged and disengaged by the control means C which determines the feeding state of the document.

The gear 52 also meshes with a gear 61 on the paper discharge unit 40 side to transmit power to the reversing roller 42 and the paper discharge roller 46.

 Next, the operation will be described.

The document sheet placed on the document tray 11 is fed by the pickup roller 21 and separated by the separation roller of the paper feeding unit 20.
By the action of 24 and the separation pad 25, the sheets are separated into one sheet, the posture is adjusted with the edge of the sheet abutting the registration rollers 26, 27, and the sheet is stopped at this position and the feeding timing is measured.

When the sheet hits the registration rollers 26, 27, the drive motor MT2 is stopped, and at the same time, the clutch means 60 is in the engaged state. Therefore, the registration rollers 26, 27 are fully loaded by the belt rollers 32, 33 of the transport unit 30, the transport belt 34, etc., and the quality of the original sheet is stiff.
Even if the drive motor MT1 on the side continues to feed the rear portion of the sheet, the registration rollers 26 and 27 do not rotate together.

Next, the drive motor MT2 is started while the clutch means 60 is in the engaged state, and the original sheet is delivered to the conveying section 30,
It is sent onto the platen P of the image forming apparatus. During this time, the registration sensor 28 detects the size of the original document, and after advancing by a predetermined amount, the clutch means is disengaged, and the drive motor MT2 rotates in the reverse direction to stop the rear sheet end at the stop reference position shown in FIG. .

Simultaneously with the above stop, the clutch means 60 is again in the connected state, and the original document sheet for the next feeding collides with the registration roller,
A large loop is drawn in the resist space 15 to wait.

During the above operation, the preceding original sheet previously sent to the platen P has been subjected to the exposure processing of the image forming apparatus on the platen P.

When the exposure is completed, the drive motor MT2 starts the normal rotation again, sends the sheet on the platen P to the paper discharge section 40, and keeps the clutch means 60 in the engaged state.
The registration rollers 26 and 27 are also driven to feed the waiting original document sheet for the next feeding onto the platen P.

As described above, since the registration rollers 26, 27, the conveyance unit 30, and the paper discharge unit 40 are driven by the single drive motor MT2, the original sheet on the platen P and the original document waiting at the registration roller position. The so-called step feed, in which the sheets are exchanged at one time, is smoothly performed while maintaining the space between the original sheets, and further, as described above, the rotation of the registration rollers 26 and 27 is not caused by the operation of the clutch means, and the sheet posture is maintained. The adjustment of is extremely accurate.

[Advantages of the Invention] According to the paper feeding device of the present invention, in the paper feeding device including the clutch means for driving the conveying unit and the registration roller by a single driving unit to separate the registration roller from the conveying unit, When the sheet is abutted against the registration roller, the driving means is stopped, and at the same time, the clutch means is brought into a coupling state to couple the registration roller and the transport section, so that the full load of the registration roller and the transport section is achieved. Against the force of contact of the sheet with the registration roller, without changing the basic arrangement of the transport unit, the registration roller, and these common driving means, when the sheet abuts the registration roller, There is no entrainment or biting between the rollers of the sheet, and the posture of the sheet is not disturbed.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a vertical sectional side view of a sheet feeding device, FIG. 2 is an enlarged side view of the same main portion, and FIG. It is a drive system diagram of a drive means. 10 …… Paper feeder 13 …… Outside guide plate 14 …… Inner guide plate 15 …… Registration space 16 …… Sheet guide 20 …… Paper feed section 24 …… Separation roller 25 …… Separation pad 26, 27 …… Registration Roller 28 …… Registration sensor 30 …… Transporter 31 …… Side plate 32, 33 …… Belt roller 34 …… Conveyor belt 35 …… Press roller 40 …… Paper ejector 51 …… Output shaft pulley 60 …… Clutch means MT1 ...... Drive motor (for paper feed section) MT2 …… Drive motor (single drive means)

Claims (1)

(57) [Scope of utility model registration request] 1. A separating means for separating sheets one by one, a resist roller for feeding out the separated sheets after abutting the leading ends of the separated sheets to correct a posture to form a loop, and for receiving the sheets from the resist rollers. And a transport section for sending,
In a sheet feeding device having a single driving means for driving the conveying section and the registration roller, and comprising a clutch means for separating the registration roller from the conveying section, when a sheet is abutted against the registration roller, A sheet feeding device comprising: a control unit that stops the driving unit and puts the clutch unit into an engaged state.