JPH0312762Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a sheet guiding device for accurately guiding original documents, transfer paper, and other sheets to the nip portion of a feed roller in a copying machine or the like.

"Background of the invention" First, an outline of an entire copying machine equipped with an automatic document feeder, which is the background of the invention, will be explained with reference to the drawings. Here, FIG. 1 is a side sectional view of the entire copying machine, and FIG. 2 is a side sectional view of the registration roller section of the automatic document feeder.

In FIG. 1, the entire copying machine 1 is shown, and the copying machine 1 includes a document table 2 made of a transparent plate or the like on which a document is placed during copying work, and a document table 2 installed on the top of the document table 2. An exposure scanning device consisting of an automatic document feeder indicated by 3, a lens 5 which is built in a cover 4 and moves in the horizontal direction in FIG. 1 to change the magnification, and a light source and mirror which move along the document table 2. means 6, a photosensitive drum 7 whose surface is exposed and scanned by the exposure scanning means 6, and a toner applied to the electrostatic latent image formed on the surface of the photosensitive drum 7 to be developed into a toner image. a developing device 8, and one or more paper feed cassettes 9a, 9b, . . .
A conveyance path 11 that conveys the copy paper taken out from the paper feed section 9 to the paper output tray 10 via the surface of the photosensitive drum 7, and a conveyance path 11 that conveys the copy paper taken out from the paper feed section 9, which is made of... The main components include a fixing device 14, which includes a heat roller 15, a pressure roller 16, and the like, which fix the toner image onto copy paper.

On the other hand, as shown in FIG. 1, the top surface of the automatic document feeder 3 is entirely covered by a series of covers 17, and a hinge structure (not shown) attached to the cover 17 allows the copying machine 1 to It is swingably mounted on the document table 2, and by this opening/closing operation, the document placed on the document table 2 can be manually fed and ejected. Between the belt drive roller 18 provided horizontally within the cover 17 and the driven roller 20 provided on the downstream side of the belt drive roller 18 in the document feeding direction as indicated by the arrow 19, there is a wide, white roller. A document conveying belt 21 is attached, and a plurality of pressing rollers 2 for pressing the document conveying belt 11 against the document table 2 are attached to the intermediate portion thereof.
2 is installed.

Further, on the upstream side of the belt driving roller 18 in the document feeding direction, there are a registration roller 23, a document feeding roller 24a, and a document feeding start roller 25.
are provided in this order, and the registration roller 2
Reference numeral 3 includes a pair of upper and lower rollers that nip and send out the original, and a roller that once stops the original sent out from the original feeding roller 24a and aligns the original, and then sends out the original in the direction of the original conveying belt 21. It is. Further, the document feed roller 24a has an arcuate notch 24' (see FIG. 2) in a part of its outer periphery and rotates in the document feed direction.
A double-feed prevention roller 24b without a notch that rotates in the opposite direction to the document feeding direction is provided at the bottom of the roller 24b. The document feed start roller 25, which plays the role of alignment, swings up and down from the position shown by the solid line in the figure to the position shown by the two-dot chain line, and feeds the document D placed on the document tray 26. This is for conveying in the direction of the roller 24a.

Further, on the downstream side of the document conveyance belt 21, there is a guide plate 27 for inverting the document sent out by the document conveyance belt 21 by 180 degrees after the completion of exposure of the document and discharging it onto the cover 17; Discharge rollers 29a and 29b are provided.

When continuously feeding documents in such an automatic document feeder 3, a drive source motor (not shown), which is a drive source on the side of the automatic document feeder 3, is normally driven first, and a document feed start signal causes the document to be fed. The start roller 25 descends and is pressed against the document D, and the document feed start roller 25, document feed roller 24a, and double feed prevention roller 24b rotate, so that only the top layer document D' of the stacked documents D is rotated. The documents are fed out, inserted into the nip point N of the registration rollers 23, and aligned. In this way, the document feed roller 24a is stopped again at the position where it has rotated once, and then the registration roller 23 begins to rotate and feeds the document D' inserted into the nip point N in the direction of the document conveyance belt 21. The document is sandwiched between the document conveyance belt 21 and the document table 2, and is conveyed by the document conveyance belt 21 to a predetermined copying position, and a copying operation is performed at that position.

"Problem" By the way, in the conventional automatic document feeder, in order to convey the normally fed document D' from the document feed roller 24a to the nip point N of the registration rollers 23, there is a gap between these rollers as shown in FIG. As shown in FIG. The nip point N is located approximately at the center of the document conveyance path 33 in order to nip the leading end 34 of the advancing document conveyance D. Therefore, the first
The roller 23a (the mounting position is fixed relative to the document guide plate 28) and the second roller 23b (the first roller 23b)
A plate spring 3 is provided below the document guide 31.
The rolling contact portions 36a and 36b of the lower second roller 23b (which is elastically supported by the lower document guide 31, so that when the leading edge 34 of the document D' sent out by the document feed roller 24a advances along the upper surface of the lower document guide 31 while hanging down due to its own weight, As shown in the second figure, the document D' may come into contact with the rolling contact portion 36b of the stopped registration roller 23, and the advance of the document D' may be blocked. In this way, the manuscript that should originally be led to the nip point N
Since the tip of D' comes into contact with the rolling contact portion 36b and cannot advance, the registration roller 23
When the original is not fed even if the original is rotated, or when the leading edge 34 of the original D' is tilted with respect to the axis of the registration roller 23, and the original D' is sent out in an oblique position. This was causing operational problems.

Such problems occur not only in the automatic document feeder described above, but also in registration rollers for document feeders with a similar structure, in which an operator manually feeds documents one by one, and in copying machines, in which transfer paper is conveyed. The same points can be made regarding the registration rollers provided in the parts.

"Purpose of the invention" Therefore, the present invention aims to solve the above-mentioned problems.

"Structure and operation of the invention" In order to achieve the above object, the main structure of the invention is such that the nip portion between the first roller that rolls into contact with each other and the second roller provided below the first roller is in the upper part. In a device that is located in a sheet conveyance path between a guide guide and a lower guide guide and that guides the leading edge of a sheet conveyed in the sheet conveyance path, the second roller is supported by an elastic member, and the second roller is supported by an elastic member; A part of the elastic member is disposed along the sheet feeding direction in the sheet conveying path on the upstream side of the nip section when viewed in the feeding direction, protruding upward from the lower guide. .

Since the present invention is a sheet guiding device, it can be used not only for automatic document feeders as described in the embodiments to be described later, but also for various applications such as document feeders, transfer paper feeding devices for copying machines, and other film-like devices. It can be used as a feeding device for sheet-like objects.

Therefore, according to the present invention, a sheet fed in a direction near the nip point between the first roller and the second roller is provided in the sheet conveying path with a portion of the guide protruding upward from the lower guide. It is directed and sent along a portion of the elastic member in the direction of the nip point using the elastic member as a guide.

``Example'' Next, an example in which the present invention is applied to a registration roller portion of an automatic document feeder will be described with reference to the attached drawings from FIG. 3 onwards to provide an understanding of the present invention. 3 is a side sectional view of the registration roller portion, FIG. 4 is a perspective view of the second roller and its mounting member, and FIG. 5 is a plan view showing the state in which the second roller and its mounting member are mounted. Note that the same reference numerals are used for elements common to those shown in FIGS. 1 and 2.

In FIG. 3, the lower document guide 31a is provided with a hole 40 (see FIG. 5) that is square in plan view. The first roller 23 is moved so that the rolling contact portion 36b with the lower document guide 31a protrudes into the document transport path 33 above the lower document guide 31a.
A is positioned, and the second roller 23b is pressed against the first roller 23a. The pressing force of the second roller 23b on the first roller 23a is given by the elastic force of the attachment member 41, which is an example of an elastic member.

That is, the mounting member 41 is constituted by a plate spring, and as shown in FIGS. 3 to 5, the lower document guide 31a
A mounting portion 41a is fixed to a part of the
A guide plate portion 43 is bent at a substantially right angle from the mounting portion 41a and protrudes into the document conveyance path 33 through the hole 40, and a second roller protrudes from the tip of the guide plate portion 43 in the document conveyance direction. bifurcated roller support parts 44a, 44a that rotatably support 23b;
It is composed of.

The angle θ of the guide plate portion 43 with respect to the lower document guide 31a is relatively small, so that the leading edge 34 of the document D' that has advanced along the upper surface of the lower document guide 31a easily rides on the guide plate portion 43 without resistance. It is configured so that it can be advanced along its upper surface.

Further, the angle θ is set at such an angle that the leading edge 34 of the document D' traveling along the guide plate portion 43 is continuously inserted into the nip point N.

Therefore, as shown in FIG.
When closed, the first roller 23a moves to the second roller 23.
b, and the second roller 23b is pressed against the mounting member 41.
Due to the elastic force of the roller 23a, it is brought into close contact with the first roller 23a.
When the feed roller 24a rotates once when the registration roller 23 stops, the document D' is sent into the document conveyance path 33, and its leading edge 34 advances in the conveyance direction along the upper surface of the lower document guide 31a. , eventually climbed onto the guide board section 43,
It is guided by the guide plate portion 43 and inserted into the nip point N between the first roller 23a and the second roller 23b.
When the registration rollers 23 begin to rotate in this state, the leading edge 34 of the document D' remains parallel to the axis of the registration rollers 23 and is sent out in an orderly direction toward the copying position. The guide plate portion 43 that protrudes upward from the lower document guide 31a described above is an example of a part of the elastic member that guides the document D'.

"Effects of the Invention" As described above, in the present invention, the nip portion between the first roller and the second roller provided below the first roller, which are in rolling contact with each other, is connected to the upper guide guide and the lower guide guide. The second roller is supported by an elastic member, and the nip is located in a sheet conveyance path between the rollers and guides the leading edge of a sheet conveyed in the sheet conveyance path. A part of the elastic member is disposed along the sheet feeding direction in the sheet conveyance path on the upstream side of the sheet conveyance path so as to protrude upward from the lower guide.

Therefore, since the sheet can be guided to the nip point by a part of the member that supports the second roller, the structure is simple, and without increasing the number of parts, mistakes in sheet feeding can be prevented, and sheet feeding can be carried out in an orderly manner. realizable.

[Brief explanation of the drawing]

FIG. 1 is a schematic side sectional view of the entire copying machine equipped with an automatic document feeder, FIG. 2 is a side sectional view of the registration roller portion of the automatic document feeder, and FIG. 3 is a side sectional view of the registration roller portion. FIG. 4 is a perspective view of the second roller and its mounting member, and FIG. 5 is a plan view showing the state in which the second roller and its mounting member are attached. Explanation of symbols, 23a...first roller, 23b...
...Second roller, N...Nip point (nip part),
D'...Original (sheet), 41...Mounting member (elastic member), 33...Document transport path, 31a...Lower document guide (lower guide), 32...Upper document guide (upper guide), 43... Information board section.

Claims (1)

[Scope of utility model registration request] A nip portion between a first roller and a second roller provided below the first roller that roll into contact with each other is located within the sheet conveyance path between the upper guide and the lower guide, and the sheet conveyance path In a device for guiding the leading edge of a sheet conveyed within the
The second roller is supported by an elastic member, and a part of the elastic member is protruded upward from the lower guide guide into the sheet conveying path on the upstream side of the nip section when viewed in the sheet feeding direction. A sheet guiding device characterized in that it is arranged along the feeding direction of the sheet.