JPH0748597Y2 - Document feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention clamps an original between a wide endless belt and a platen of an image forming apparatus and sends the original so that the original can be undulated at the edge of the platen. The present invention relates to a document feeding device that stops a document by a document stopping means provided and causes an image forming apparatus to perform an exposure process.

[Prior Art] In a document feeding device that feeds a document by sandwiching it between a wide endless belt and a platen of an image forming apparatus, it is necessary to accurately orient the document at a predetermined position of the platen. For this reason, a document stopping means is provided so as to rise and fall facing the end edge of the platen, and when the document advances a little before the document stopping means, the endless belt for conveyance is cut off from the driving means to allow inertia. The document is stopped by being brought into contact with the front contact portion of the stopping means in a state where the document advances.

However, in the document stopping means in such a document feeding device, there is only one contact surface with which the leading end portion of the document comes into contact, and when the contact surface cannot be stopped, the stopping means and the endless belt are combined. There is a problem that the document is caught between them and sticks out, and the stop position is likely to be inaccurate.Therefore, for example, as in Japanese Patent Publication No. 62-45135, a sharp portion of the top of the stop means is slidably contacting the belt. Solutions have been taken such as making an edge, or applying a rake angle to the surface of the document that contacts the front edge of the document.

[Problems to be Solved by the Invention] However, in such a conventional document feeding apparatus, there is a problem that the sharp top of the stopping means is dangerous to the operator. Further, if the top is rounded in order to avoid such a danger, there still remains a problem that the manuscript easily gets over.

[Object of the Invention] The present invention has been made in view of the above-mentioned conventional problems. The top of the document stopping means, which is in contact with the endless belt, is not sharp but has a rounded shape, and the document leading edge is also sharp. An object of the present invention is to provide a document feeding device which is configured so that the document is hard to get over and the document leading end has a chance to come into contact with the document many times, and the document can be reliably stopped at a predetermined position of the platen.

[Means for Solving the Problem] (1) A document is stretched between a pair of belt rollers and stretched by a plurality of restraining rollers, and a document is placed between the wide endless belt and the platen of the image forming apparatus. The original is stopped by holding the original by abutting the front end of the original stop means arranged so as to be held up and down so as to face the edge of the platen and to rise and fall, and then exposed by the image forming apparatus. In a document feeding device for performing processing, the contact portion of the document stopping means is constituted by a plurality of steps, and each end corner portion of the step portion is connected so that an envelope surface has a substantially circular cross section. Formed document feeder.

(2) The document feeding according to claim 1, wherein the holding roller of the endless belt is arranged so that a portion of the endless belt which comes into contact with the document stopping means is slidably contacted so as to wind along the envelope having a circular cross section. apparatus.

(3) The document feeder according to the above items 1 and 2, wherein the corners of the uppermost step are rounded.

Can be achieved by

[Operation] The document fed by being sandwiched between the endless belt and the platen of the image forming apparatus comes into contact with the front abutment surface of the document stopping means which rises and falls facing the edge of the platen and stops.

Therefore, since the contact portion of the stopping means has a small width in the moving direction of the document and is constituted by a plurality of step portions each having a contact surface having a minute height in the upward direction, Even if the tip end of the contact part does not stop properly by contacting the first contact surface, there is an opportunity to contact the second contact surface of the second stage. You can stop at.

Also, the enveloping surface formed by connecting the end corners of each step has a substantially circular cross section, and the end corner of the uppermost step is rounded so that the endless belt can be wrapped around it. The leading edge of the document can be reliably caught by any step and stopped.

The width of each step in the direction of travel of the original document is extremely small, and since the top of the uppermost stage is formed by rounding the circular cross section, there is no sharpness and there is no danger.

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

FIG. 1 is an overall view of the document feeding device 10.

The document feeding device 10 is placed on the platen P of the image forming apparatus C and feeds a document from the document tray 11 onto the platen P to receive an exposure process. A paper feed unit 20 that separates and feeds a document, a transport unit 40 that transports the document onto the platen P, positions it at a stop reference position P ₁ for exposure processing, and then transports the document, and transports the document from the transport unit 40. It is configured with a discharge unit 50 that receives and discharges the received sheet onto the sheet discharge tray 12.

The paper feed unit 20 is a pickup roller 21 that comes out in contact with the bottom sheet of the stacked documents, and a weight leaf spring that presses the top sheet.
22, a stopper 23 for temporarily stopping the leading edge of the document, a separation roller 24 for contacting and separating the lowermost paper sheet, a separation pad 25 for preventing the second paper sheet and above, an outer guide plate 26 and an inner guide plate 27 constituting a resist space 28, Registration roller 30, same pinch roller 3
1, a linear guide portion 29 that guides the original to the registration roller 30, a registration sensor 32 that detects the leading edge and the trailing edge of the original, and a paper feed guide portion 33 that guides the original to just before the entrance of the conveyance section 40.
Etc.

The paper feeding unit 20 is controlled and driven by MOTI.

The transport section 40 is formed by stretching a transport belt 43, which is an endless belt, between a pair of belt rollers 41 and 42, and a plurality of holding rollers 44a to 44d are disposed on the platen P side of the transport belt 43.

Further, a document stopping means 60 which is undulated facing the end edge portion of the platen P corresponding to the document stop reference position P ₁ is provided while being pivotally supported by a pivot 61.

FIG. 3 shows a state in which the document stopping means 60 is lifted up, and FIG. 2 shows the front contact portion 62 in an enlarged manner.

The contact portion 62 has minute width portions h _{1 to} h ₄ in the moving direction of the document, and is constituted by a plurality of step portions 62a to 62d having contact surfaces k _{1 to} k ₄ above.

In particular, the contact surface k ₄ of the first step portion 62a constitutes a relatively high vertical wall which is substantially vertically raised, and most originals abut against the contact surface k ₁ and stop.

A small width h ₂ is provided in the document advancing direction from the upper end corner α of the contact surface k ₁ of the first step portion 62a, and the second step portion is provided substantially vertically above.
The contact surface k _{2 of} 62b is formed, and the first contact surface k _{1 is formed.}
A second chance is offered if the outage fails. Then, a minute width h ₃ is provided from the end corner portion β of the _second contact surface k _{2, and} a third step portion 62c is further formed, and further from the end corner portion γ via the minute width h _{4 a} fourth step portion upward. The portion 62d is provided, and in this embodiment, there are four chances of stopping the contact for convenience.

Each of the end corners α, β, γ is formed sharply, but the end corner δ of the uppermost fourth step portion 62d is slightly rounded, and each end corner α, An envelope surface A connecting β, γ and δ is formed to have a substantially circular cross section.

Further, as shown in FIG. 3, when the document stopping means 60 is lifted up, the conveying belt 43 is provided with a pressing roller 44a so as to wind around the envelope surface A.

The discharge unit 50 includes a discharge guide 51 that passes around a large-diameter discharge roller 52 that receives and sends a document from the transport unit 40, and a reverse feed guide 54 that guides the back surface of the document to the transport unit 40 again for copying. The pinch rollers 56a and 56b are provided.

Further, a switching claw 53 is provided at the end of the discharge guide 51 for switching whether the document is discharged as it is or sent again to the transport section 40, and a discharge roller 57 is provided at the discharge port.

Further, a paper discharge sensor 55 is arranged near the entrance of the discharge guide 51.

Next, the operation will be described.

When the originals are stacked on the original tray 11 and a start button (not shown) is pressed, the pickup roller 21 sends the bottom sheet and a plurality of originals connected thereto, and the separation roller 24
By the action of the separating pad 25, only the bottom original is separated and sent. Then, in the state where the front end is nipped between the registration roller 30 and the pinch roller 31, the rear part draws a loop in the registration space 28 and the posture is adjusted, and then the paper is fed into the conveyance part 40 via the paper feed guide part 33. It

In the transport unit 40 driven by the MOTII, the document is sandwiched between the platen P and the transport belt 43 and fed, and when the document comes just before the stop reference position P ₁ , the MOTII stops and the transport belt 43 Rotates by inertia and sends the document. At the same time, the document stop means 60 moves up.

Even if the leading edge of the document comes into contact with the contact surface k ₁ of the first stepped portion 62a of the document stopping means 60, the conveyance belt 43 is still moving by inertia, so the posture of the document is adjusted here, and the document continues to move. Then, the exposure process is performed by the image forming apparatus C.

When the leading edge of the document has crossed over the _first contact surface k ₁ , it reaches the second stepped portion 62b and stops there. In this way, in the present embodiment, there are four chances of stopping operation at the maximum, and on the other hand, the inertia of the transport belt 43 is gradually weakened, so that the original is always placed on any one of the contact surfaces k _1. Stopped by ~ k ₄ . Moreover, the envelope surface A connecting the end corners α to δ of the step portions 62a to 62d has a substantially circular cross section, and the conveyor belt 43 slides along the envelope surface A. Is the edge corner α of any of the stepped portions 62a to 62d
~δ and in contact may be the tip of the abutting surface k abutting document ₁ to k ₄ can be captured reliably in the step portion.

Further, each of the minute width portions h _{2 to} h ₄ is an extremely small amount (for example, about 0.2 mm), and even if the minute width portions h _{2 to} h ₄ are stopped at the fourth step portion 62 d, the error of the entire stop position is less than 1 mm. There is no problem in formation. Incidentally, since the stop reference position P ₁ as shown in FIG. 2 is set to past the width portion h ₁ of the first step portion 62a, an error as long as the reference the position P ₁ is as described above become.

When the exposure process is completed, the document stop means 60 falls down below the platen P surface, the MOTII is started, the document is sent to the discharge section 50, and finally discharged to the discharge tray 12.

When performing back exposure, the switching claw 53 rotates clockwise in FIG.
Resent to 40.

[Advantage of the Invention] According to the document feeding apparatus of the present invention, since the contact part of the document stopping means is composed of a plurality of step portions, the document has a contact chance for a plurality of stops, It is possible to surely stop, and it is possible to perform accurate exposure processing without positional deviation.

The envelope surface formed by connecting the end corners of the stepped portion is formed to have a substantially circular cross section, and the portion of the endless belt that contacts the document stopping means is wound along the envelope surface having the circular cross section. Since the pressing roller is arranged so as to come into sliding contact with the document, even if the document comes into contact with any of the contact surfaces, it is difficult for the document to protrude from the contact surface, and the document can be stopped more reliably.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention.
FIG. 2 is an overall configuration diagram of the document feeding apparatus, FIG. 2 is a structural diagram of an abutting portion of the document stopping unit, and FIG. 10 …… Original feeder 20 …… Paper feed unit 40 …… Conveyor unit 41 …… Belt roller 42 …… Belt roller 43 …… Conveyor belt (endless belt) 44a-44d …… Pressing roller 50 …… Ejection unit 60 ...... Document stopping means 61 …… Pivot 62 …… Front contact part 62a …… First step 62b …… Second step 62c …… Third step 62d …… Fourth step k _{1 to} k ₄ … ... 1st to 4th contact surfaces α to δ ... 1st to 4th end corners A ... Envelope surface of end corners C ... Image forming device P ... Platen P ₁ ... Document stop reference position

Claims (3)

[Scope of utility model registration request] 1. A document is sandwiched between a wide endless belt stretched by a pair of belt rollers and stretched by a plurality of restraining rollers, and a platen of an image forming apparatus, and an edge portion of the platen is fed. In the original feeding device for stopping the original by bringing the leading end of the original into contact with the front abutting portion of the original stopping means that is arranged so as to rise and fall, the original feeding apparatus performs the exposure processing by the image forming apparatus. The abutting portion of the document stopping means is constituted by a plurality of steps in the direction of travel of the document, and the envelope surface formed by connecting the end corners of the stepped portion is formed to have a substantially circular cross section. Document feeder that does. 2. The restraining roller of the endless belt is arranged so that a portion of the endless belt which comes into contact with the document stopping means is slidably contacted so as to wind around the envelope having a circular cross section. 1. The document feeder according to 1. 3. The document feeder according to claim 1 or 2, wherein the uppermost step has a rounded corner.