JP2008207890A - Paper feed device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure stability in conveying while surely detecting conveyance of paper. <P>SOLUTION: A paper feed device is equipped with a tray 121 for loading paper sheets, a first conveying path for conveying the paper sheets loaded on the tray 121, an intermediate roller 125 provided downstream of the first conveying path, and a detection part including a detector 11 for detecting whether or not the paper sheet is conveyed to the intermediate roller 125. The detection part has an actuator 10 turning at a fixed angle where the tip end part 10a contacting with the paper to be conveyed is provided, and the tip end part 10a is positioned at the inner side of both ends of the intermediate roller 125a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a paper feeding device used in an image forming apparatus such as a copying machine, a printer, and a FAX, and an image forming apparatus using the same.

  2. Description of the Related Art Conventionally, image forming apparatuses such as copiers and printers have a built-in paper feeding device that supplies paper to be subjected to image formation. FIG. 5 is a schematic configuration diagram of such an image forming apparatus.

  As illustrated in FIG. 5, the image forming apparatus 100 generates an image as a toner image and forms an image on the sheet supplied from the manual feed tray 110 or the sheet feeding device 120, and the toner image on the sheet. An image fixing unit 140 that fixes the printed matter is provided.

  The paper feeding device 120 includes a plurality of paper feeding devices 120a to 120d stacked vertically below the image forming unit 130 and the like. Each of the paper feeding devices 120a to 120d has the same configuration. The configuration is an example of the paper feeding device 120a. The tray 121 for stacking paper and the paper from the tray 121 for guiding the paper to the image forming unit 130 are used. A carry-out roller 122 is provided.

  Further, in the paper feeding device 120, apart from the first conveyance path 123 formed by the tray 121 and the carry-out roller 122, the second conveyance for passing the paper conveyed from the paper feeding device located at the lower stage. A path 124 is provided. An intermediate roller 125 is provided downstream of the second conveyance path 124, and in each sheet feeding device, the first conveyance path 123 and the second conveyance path 124 are joined by the intermediate roller 125. ing.

  The second transport path 124 communicates with the bottom surfaces of the paper feeding apparatuses 120a to 120d to form one vertical path, and transports from the first transport path 123 of the paper feeding apparatuses 120a to 120d. The sheets that have been merged are merged into the vertical path and carried into the image forming unit 130.

  Next, FIG. 6 is a perspective view schematically showing a main part of the paper feeding device 120 (120a to 120d). As shown in FIG. 6, the intermediate roller 125 is composed of a roller 125 a that rotates and a roller 125 b that is driven by the rotation of the roller 125 a, a sheet that is conveyed through the first conveyance path 123 by the carry-out roller 122, The sheet conveyed from the second conveyance path 124 passes through the nip of the intermediate roller 125.

  An actuator 126 is provided next to the intermediate roller 125. The actuator 126 includes a protrusion 126a provided so as to block the sheet passing position indicated by a one-dot chain line in the figure, which is a merging point between the first conveyance path 123 and the second conveyance path 124, and the protrusion 126a. And a rotation shaft 126b provided at one end. The other end of the rotation shaft 126 is connected to a detection unit using an optical sensor (not shown), and when the rotation shaft 126 is rotated by contacting the projection 126a with the conveyed paper, the rotation is detected. Then, the passage of the paper is detected.

  Such an actuator 126 is used to detect the presence / absence of conveyance of a sheet from the sheet feeding device 120, and thus it is possible to check the occurrence of a paper jam, a conveyance failure, and the like.

  However, the conventional paper feeder has the following problems.

  FIG. 7 is a plan view schematically showing a main part of the paper feeding device 120 (120a to 120d). As shown in FIG. 7, the actuator 126 needs to be positioned at the junction of the first conveyance path 123 and the second conveyance path 124, so that the projection 126a is positioned substantially on the same plane as the intermediate roller 125. Will do. At this time, the protrusion 126a is disposed to face the end 125c of one roller 125a of the intermediate roller 125.

  Since the protruding portion 126a needs to detect the presence or absence of conveyance regardless of the size of the paper, it is arranged at a position closer to the center portion in the figure in order to contact the paper of a small size (B5 size, etc.). There is a need to.

  However, when the protrusion 126a is moved closer to the center, the end 125c of the roller 125a is also moved closer to the center.

  At this time, if it is attempted to maintain the roller width of the intermediate roller 125 as before, the arrangement of the intermediate roller 125 becomes asymmetric with respect to the center of the sheet passing position.

  If the arrangement of the intermediate roller 125 is kept at the center of the sheet passing position, it is necessary to shorten the roller width.

  If the arrangement of the intermediate roller 125 is made asymmetrical or the roller width is shortened in this way, a biased force is applied to the paper sandwiched between the intermediate rollers at the time of conveyance, which impairs the stability of conveyance and causes paper jams, etc. Cause.

  SUMMARY An advantage of some aspects of the invention is that a sheet feeding device and an image forming apparatus using the sheet feeding device that can ensure stability during conveyance while reliably detecting conveyance of the sheet are provided. The purpose is to provide.

In order to achieve the above object, a first aspect of the present invention includes a stacking unit for stacking sheets,
A first transport path for transporting sheets stacked on the stacking unit;
An intermediate roller provided downstream of the first transport path;
A detection unit that detects whether or not the sheet is conveyed to the intermediate roller,
The detection unit includes a rotatable actuator provided with a contact unit that comes into contact with the sheet to be conveyed,
The contact portion is a paper feeding device that is located inside both ends of the intermediate roller.

The second aspect of the present invention further includes a second transport path for transferring paper carried from the outside,
The intermediate roller is the sheet feeding device according to the first aspect of the present invention, which is provided at a junction or downstream of the first conveyance path and the second conveyance path.

In the third aspect of the present invention, the intermediate roller has a plurality of sub-rollers arranged in parallel.
The contact portion is the sheet feeding device according to the first or second aspect of the present invention, which is located at any one of the plurality of sub rollers.

  A fourth aspect of the present invention is the paper feeding device according to the first or second aspect of the present invention, wherein the actuator is rotatably held on a rotation shaft of the intermediate roller.

Further, according to a fifth aspect of the present invention, the actuator includes the contact portion at one end, and a shutter that transmits the behavior of the contact portion to the detection portion at the other end.
The portion other than the contact portion and the shutter is the paper feeding device according to the fourth aspect of the present invention, which is formed along the periphery of the outer shape of the intermediate roller.

  A sixth aspect of the present invention is an image forming apparatus including any one of the first to fifth paper feeding devices.

In the seventh aspect of the present invention, a plurality of the sheet feeding devices are stacked one above the other.
In each of the sheet feeding devices, the second conveyance path is an image forming apparatus according to a sixth aspect of the present invention, which transfers the sheet conveyed from the first conveyance path of the sheet feeding device located at a lower stage. is there.

  According to the present invention as described above, stability during conveyance can be ensured while reliably detecting conveyance of a sheet.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1A is a plan view showing a main part of the paper feeding device according to the embodiment of the present invention, and FIG. 1B is an enlarged view of the main part. FIG. 2 is a perspective view showing a main part. FIG. 3 is a perspective view showing the configuration of the actuator 10 as a single unit. FIG. 4 is a schematic side view for explaining the operation of the actuator 10 and the intermediate roller 125. 1-4, the same code | symbol is attached | subjected to FIG. 5-7 and an equivalent part, and detailed description is abbreviate | omitted.

  The sheet feeding device according to the present embodiment includes the actuator 10 mounted on the rotation shaft of the roller 125a on the rotation side of the intermediate roller 125 and the detector 11 that detects the conveyance of the sheet based on the rotation of the actuator 10. Features.

  As shown in FIGS. 1A and 1B, the actuator 10 is provided along the roller 125a, and the tip end portion 10a is located between the rollers 125a and 125b. Further, the detector 11 shown in FIG. 1A is provided on the conveying roller 122, and a shutter 10c of an actuator 10 described later enters inside.

  As shown in FIG. 2, the roller 125a is composed of sub-rollers 125a1, 125a2, and 152a3 provided coaxially with the rotation shaft, and the tip 10a of the actuator 10 is located between the sub-rollers 125a1 and 125a2. Located in the void. In FIG. 2, the roller 125b on the driven side of the intermediate roller 125 is omitted for explanation.

  Next, as shown in FIG. 3, in the actuator 10, a part of the rotation shaft 10 b goes around the outside of the sub roller 125 a 3 to form an avoiding portion 10 e for avoiding contact with the sub roller 125 a 3. Yes.

  Further, at both ends of the avoiding portion 10e, holding portions 10d having a shape along the surface of the rotating shaft of the roller 125a are formed. Further, a tip portion 10a is formed extending from the holding portion 10d corresponding to one end of the rotating shaft 10b.

  As shown in FIGS. 2 and 4, when the holding portion 10d is fitted from the outside of the rotation shaft of the roller 125a, the actuator 10 is coaxially mounted around the roller 125a and fixed rotatably. Since the inner wall of the holding portion 10d slides on the rotation shaft of the roller 125a, the actuator 10 does not follow the rotation of the roller 125a. Further, the sub roller 125a rotates inside the avoidance portion 10e.

  Therefore, each member constituting the intermediate roller 125 operates in a non-contact manner with the actuator 10 except for the holding portion 10d.

  Next, referring again to FIG. 3, a shutter 10c is formed at the other end of the rotation shaft 10b. The shutter 10c moves up and down in the direction of the arrow in the drawing according to the rotation of the actuator 10.

  As shown in FIG. 2, the shutter 10c is arranged so as to intersect the optical path of the detector 11 having a photodetector (not shown), and the signal output of the photodetector is turned on when the detector 11 changes the optical path due to the movement of the shutter 10c. By turning off / off, the presence / absence of sheet conveyance is detected.

  In the above configuration, the paper feeding devices 120a to 102d correspond to the paper feeding device of the present invention, and the tray 121 corresponds to the stacking unit of the present invention. The first transport path 123 of the present invention corresponds to the first transport path of the present invention, and the second transport path 124 corresponds to the second transport path of the present invention. The intermediate roller 125 corresponds to the intermediate roller of the present invention, the sub rollers 125a1 to 125a3 correspond to the sub roller of the present invention, the detector 11 and the actuator 10 correspond to the detection unit of the present invention, and the actuator 10 corresponds to the present invention. The tip portion 10a corresponds to the contact portion of the present invention, and the shutter 10c corresponds to the shutter of the present invention.

  The operation of the sheet feeding device 120a will be described below with reference to FIG.

  In the actuator 10, the tip end portion 10 a is a gap formed by the pair of rollers 125 a and 125 b of the intermediate roller 125, and a position that intersects the main conveyance direction indicated by a one-dot chain line in the drawing is maintained at the initial position. The actuator 10 receives a biasing force from a spring (not shown), and, as described above, the rotation shaft of the roller 125a slides and rotates within the holding portion 10d, so that the tip portion 10a is not affected by the rotation of the intermediate roller 125. Keep the initial position.

  Next, when the paper from the first transport path or the second transport path is transported from the direction of the one-dot chain line in the figure, the leading end 10a is pushed up by the leading edge of the paper, and the actuator 10 thereby causes the roller 125a to move. It rotates at the maximum angle θ with respect to the center of rotation. As the actuator 10 rotates, the shutter 10c shown in FIG. 3 shields the optical path of the detector 11, and the signal output of the photodetector is turned on or off, thereby detecting the presence or absence of the conveyance of the paper.

  When the sheet passes through the intermediate roller 125, the leading end 10a returns to the initial position.

  As described above, in the sheet feeding device of the present embodiment as described above, in the actuator 10, the rotation shaft 10b is fitted to the roller 125a on the rotation side of the intermediate roller 125, and the rotation center is the roller 125a. The configuration of the coaxial arrangement was made to coincide with the center of rotation. According to such a configuration, the front end portion 10a can be positioned between the sub rollers 125a2 and 125a3 constituting the roller 125a, which are inside the both ends of the intermediate roller 125.

  Therefore, as shown in FIG. 2, since the arrangement of the end 125c of the roller 125a is not affected by the arrangement of the actuator 10, the degree of freedom in designing the intermediate roller 125 including the roller 125a can be increased.

  As a result, as shown in FIG. 1, the intermediate roller 125 can have a larger overall width W while being configured to be symmetrical with respect to the center of the passing position of the paper to be transported, thereby improving stability during transport. Can be increased.

  Further, since the tip end portion 10a of the actuator 10 can be disposed near the center of the intermediate roller 125, it is possible to reliably detect the presence or absence of conveyance even when a small sheet is conveyed.

  In the above description, the tip portion 10a is arranged between the sub rollers 125a2 and 125a3, but may be provided between the sub rollers 125a1 and 125a2.

  Further, the roller 125a is composed of three sub rollers 125a1 to 125a3, but may be composed of two or four or more sub rollers. In this case, the tip 10a may be disposed between the plurality of sub-rollers. Further, a plurality of tip portions 10a may be provided, and a plurality of tip portions 10a may be arranged between the sub rollers.

  The actuator 10 is provided on the side of the roller 125a on the rotation side, but may be provided on the roller 125b on the driven side. As shown in FIG. 1, since the driven roller 125b is also composed of a plurality of sub-rollers, the actuator 10 is provided by fitting the holding portion 10d to the rotation shaft between these sub-rollers, and between the sub-rollers constituting the roller 125b. It is possible to arrange the tip 10a in the gap.

  Further, as shown in FIG. 3, the actuator 10 is fitted on the outer side of the rotating shaft of the roller 125a by a holding part 10d that is partially opened, and has a coaxial arrangement. However, the holding part 10d has a complete annular shape. It may be configured as follows. In this case, the assembly of the roller 125a and the mounting of the actuator 10 in the sheet feeding device 120 may be performed at the same time with the rotating shaft inserted through the holding portion.

  Further, the detector 11 is provided in the vicinity of the rotation shaft of the carry-out roller 122 as shown in FIG. 2, but the shutter 10c of the actuator 10 such as a wall surface on which the rotation shaft is mounted in the sheet feeding device can be arranged. As long as it is a simple place, it may be provided at an arbitrary place.

  In short, the actuator of the present invention is not limited by its specific shape and configuration as long as the tip portion 10a can be disposed inside the full width of the intermediate roller 125.

  In the above description, the sheet feeders 120a to 120d of the present embodiment have been described as being used by being stacked on top and bottom and being combined with the image forming apparatus. However, the sheet feeder of the present invention is a single unit. It may be combined with an image forming apparatus. In this case, the second transport path 124 is omitted, and the detector 11 can detect only the presence / absence of transport of paper in the first transport path 123.

  In addition, the image forming apparatus shown in FIG. 5 includes a configuration in which the sheet feeding device of the present invention is provided as the sheet feeding device.

  The present invention has an effect of ensuring stability during conveyance while reliably detecting conveyance of a sheet, and is useful in a sheet feeding device and an image forming apparatus using the same.

(A) It is a top view which shows the principal part of the paper feeder of embodiment of this invention. (B) It is an enlarged view which shows the principal part of the paper feeder of embodiment of this invention. It is a perspective view which shows the principal part of the paper feeder of embodiment of this invention. It is a perspective view which shows the structure of the actuator 10 of the paper feeder of embodiment of this invention. It is a typical side view for demonstrating operation | movement of the actuator 10 and the intermediate | middle roller 125 of the paper feeder of embodiment of this invention. It is a typical block diagram of the image forming apparatus by a prior art. It is a perspective view which shows typically the structure of the paper feeder by a prior art. It is a top view which shows typically the structure of the paper feeder by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Actuator 10a Front-end | tip part 10b Rotating shaft 10c Shutter 10d Holding | maintenance part 10e Avoidance part 11 Detection part 100 Image forming apparatus 120,120a-120d Paper feed apparatus 125 Intermediate | middle roller 125a, 125b Roller 125a1-125a3 Sub roller

Claims (7)

A loading section for loading paper;
A first transport path for transporting sheets stacked on the stacking unit;
An intermediate roller provided downstream of the first transport path;
A detection unit that detects whether or not the sheet is conveyed to the intermediate roller,
The detection unit includes a rotatable actuator provided with a contact unit that comes into contact with the sheet to be conveyed,
The sheet feeding device, wherein the contact portion is positioned inside both ends of the intermediate roller. A second conveyance path for transferring paper carried from outside;
2. The sheet feeding device according to claim 1, wherein the intermediate roller is provided at a merging point of the first conveyance path and the second conveyance path or a position downstream thereof. The intermediate roller has a plurality of sub-rollers arranged in parallel,
The sheet feeding device according to claim 1, wherein the contact portion is located in any one of the plurality of sub rollers.   The sheet feeding device according to claim 1, wherein the actuator is rotatably held on a rotation shaft of the intermediate roller. The actuator is provided with the contact portion at one end and a shutter that transmits the behavior of the contact portion to the detection portion at the other end,
5. The sheet feeding device according to claim 4, wherein portions other than the contact portion and the shutter are formed along a periphery of an outer shape of the intermediate roller.   An image forming apparatus comprising the paper feeding device according to claim 1. A plurality of the sheet feeders are stacked one above the other;
The image forming apparatus according to claim 6, wherein in each of the sheet feeding apparatuses, the second conveyance path transfers the sheet conveyed from the first conveyance path of the sheet feeding apparatus located at a lower level.

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