JP2009073591A - Sheet member discharging device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform predetermined full condition detection even if a sheet member is discharged with both ends in curled states. <P>SOLUTION: A sheet member discharging device 2 comprises discharge roller pairs 130, a discharge tray 103, and a full loading detection mechanism 4. The full loading detection mechanism 4 comprises a turnable shaft 140 and a detection member 142 arranged in a center area of the turnable shaft 140, and a holding member 150 is supported by both side areas of the turnable shaft 140 in a relatively turnable manner. The holding member 150 is independently turned from the detection member 142 while the stacking height of paper sheets P reaches a predetermined value H1. However, after the stacking height exceeds the predetermined value H1, the holding member is integrally turned with the detection member 142. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a sheet member discharge device and an image forming apparatus (for example, a copier, a printer, a facsimile machine) including the sheet member discharge device.

A sheet discharge roller for sequentially discharging sheet members (sheet material), a sheet discharge tray for stacking sheet members discharged by the sheet discharge roller, and detecting the height of the stacked sheet members, the height is a predetermined value. Patent Document 1 discloses a sheet member discharge device including a sheet member full load detection device that outputs a signal when the value reaches. In this sheet member discharge device, the sheet member full load detection device detects the height of the sheet member at the center portion and side end portions (or both side end portions) of the sheet member, and these center portion and side end portions (or both end portions). Part) is configured to output a signal when the sheet member height reaches a specified value. The sheet member full load detection device includes a shaft portion swingably supported by the apparatus body, a first contact member attached to one end portion of the shaft portion, and a second contact attached near the center of the shaft portion. A member, a light-shielding part attached to the other end of the shaft part, and a photosensor provided in a position of the apparatus main body facing the light-shielding part.

When the sheet member is discharged to the paper discharge tray, the first contact member, the second contact member, and the light shielding portion are swung through the shaft portion. When the height of the discharged sheet member (the height of the central portion of the sheet member) reaches a specified value, the light shielding unit shields the photosensor, and the photosensor outputs a signal. On the other hand, when the sheet member is discharged and the side end portion of the sheet member is curled upward, the second contact member is pushed up and swung. When the height of the side end portion of the sheet member (the height of the curled portion) reaches a specified value, the light shielding portion shields the photosensor, and the photosensor outputs a signal.
JP-A-10-120295

According to the sheet member discharge device, the full load detection device detects the height of the sheet member stacked on the discharge tray, and outputs a signal when the height reaches a specified value. Has been. Therefore, the operator removes the sheet member from the discharge tray based on the output signal, thereby closing the discharge port of the sheet member and bending the discharged sheet member later. Can be avoided. The full load detection device detects the sheet member height at the side end of the sheet member and outputs a signal when the sheet member height reaches a specified value at the side end. Even when the side end portion of the member is curled and protrudes from the central portion, the operator can quickly detect the situation, and the operator can remove the sheet member from the paper discharge tray.

However, in the above-described sheet member discharging apparatus, when the sheet member is discharged in a curled state, a signal is output in a state where the stacked sheet members are not fully loaded. From the perspective of full load detection, further improvements are desired.

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel sheet member discharging apparatus and an image forming apparatus including the sheet member discharging apparatus capable of detecting a predetermined full load even when the sheet member is discharged in a state where both side ends are curled. Is to provide.

According to one aspect of the present invention,
A discharge means for discharging the sheet member; a discharge tray on which the sheet member discharged by the discharge means is stacked; and a height of the sheet member stacked on the discharge tray is detected and the height reaches a full load height. A full load detection mechanism that outputs a signal, and the full load detection mechanism is integrated with a rotation shaft extending in the horizontal width direction perpendicular to the discharge direction of the sheet member and a central region of the rotation shaft. A sheet member discharge device comprising: a detection member that is disposed and is rotated about a rotation shaft by a discharge operation of the discharged sheet member and detects a full height of the sheet member stacked on the discharge tray. In the device
In both side areas sandwiching the central area of the rotation shaft, the holding members that respectively hold the both end portions of the sheet member in the horizontal width direction are relatively rotated around the rotation axis by the discharging operation of the discharged sheet member. Supported as possible,
The holding member rotates independently with respect to the detection member until the stacking height of the sheet members on the discharge tray reaches a predetermined height, but after the stacking height exceeds the predetermined height, the detection member Configured to rotate integrally with
A sheet member discharging apparatus is provided.
The detection member urging means for urging the detection member in a direction opposite to the discharge direction at the home position that intersects the downstream side of the discharge means in the vertical direction, and the holding member respectively, and the downstream side of the discharge means in the vertical direction A pressing member urging means for urging in a direction opposite to the discharging direction at a home position intersecting with the urging force, and the urging force of the detecting member urging means is based on the sum of the respective urging forces of the pressing member urging means. Is preferably set larger.
Each of the pressing member urging means rotates independently from the home position up to a predetermined angle by the discharging operation of the discharged sheet member, but after the predetermined angle is exceeded, it is integrated with the detection member. It is preferable to rotate in the direction.
Each of the presser members includes a cylindrical boss that is fitted to the rotary shaft so as to be relatively rotatable, and a presser plate that extends radially outward from the outer peripheral surface of the boss. Are formed with notches or elongated holes extending in the axial direction with a predetermined circumferential width, and stoppers for the rotating shaft are formed on both side regions of the rotating shaft so that stoppers extend radially. Each of the presser members is fitted into a notch or a slot in the corresponding presser member, and one side surface in the circumferential direction of each notch or slot in the presser member is circumferentially moved to the corresponding stopper by the presser member biasing means. It is preferable that a circumferential clearance of the predetermined angle is formed between the notch or each other side surface of the elongated hole in the circumferential direction and the corresponding stopper.
According to another aspect of the invention,
An image forming apparatus comprising: an image forming unit that forms an image on a sheet member; and a sheet member discharging device that discharges a sheet member on which an image is formed by the image forming unit.
The sheet member discharge device is constituted by any one of the sheet member discharge devices described above.
An image forming apparatus is provided.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of a sheet member discharging apparatus configured according to the present invention and an embodiment of a printer that is an image forming apparatus including the sheet member discharging apparatus will be described in detail with reference to the accompanying drawings.

Referring to FIGS. 1 and 2, a printer 100 including a sheet member discharging apparatus includes a printer main body 102 that is an image forming apparatus main body. The printer main body 102 includes a rectangular parallelepiped shape portion 102a and a protruding portion 102b extending upward from the upper end of the rectangular parallelepiped shape portion 102a. The protrusion 102b is disposed at the left end in FIG. 1 at the upper end of the rectangular parallelepiped portion 102a. The upper end surface of the rectangular parallelepiped portion 102a of the printer main body 102, which is inclined rightward in FIG. 1 from the lower end of the protruding portion 102b toward the right in FIG. An extending discharge tray 103 is provided. A step 104 extending substantially vertically is formed between the upper end surface of the protrusion 102b and the lowermost portion of the discharge tray 103 (lower end of the protrusion 102b).

Referring to FIG. 1, a photosensitive drum 105, which is an image carrier, is located in the center of the printer main body 102 in the up-down direction and in a position closer to the left than the center in the left-right direction in FIG. It is arranged to be rotationally driven in the direction. Around the photosensitive drum 105, a main charger 106, a developing device 108, a transfer roller 110, a cleaning device 112, a static eliminator (not shown), and the like are provided. A laser scanning unit LSU is disposed at the center of the printer main body 102. The photosensitive drum 105, the main charger 106, the developing device 108, the transfer roller 110, the cleaning device 112, a static eliminator (not shown), and the laser scanning unit LSU constitute an image forming unit that forms an image on the paper P.

On the left side of the photosensitive drum 105 in the printer main body 102 in FIG. 1, a conveyance path 114 for conveying the paper P as a sheet member is disposed, and a paper feed cassette 116 is disposed at the lower end in the printer main body 102. Is installed. In the paper feed cassette 116, there are disposed a bottom plate 120 which is a paper placing plate whose one end is rotatably supported around a shaft 118, a compression coil spring 122 which pushes up the other end of the bottom plate 120, and the like. Yes. The upper surface of the leading end of the paper P stacked and accommodated on the bottom plate 120 is pressed against a pickup roller 124 disposed in the printer main body 102.

The conveyance path 114 passes between the photosensitive drum 105 and the transfer roller 110 and extends in the vertical direction in the tangential direction thereof. The upstream end (lower end) of the conveyance path 114 is connected to the downstream side of the pickup roller 124. A registration roller pair 126 is disposed on the upstream side of the photosensitive drum 105 in the conveyance path 114. A fixing device 128 is disposed on the downstream side of the photosensitive drum 105 in the conveyance path 114. The fixing device 128 includes a fixing roller (heat roller) 128A and a pressure roller 128B pressed against the fixing roller 128A. On the downstream side of the fixing device 128 in the transport path 114, a transport roller pair 129 and a discharge roller pair 130 are disposed downstream in this order. A discharge roller pair 130 that is a discharge unit that discharges the paper P to the discharge tray 103 is disposed substantially inside the stepped portion 104 of the protruding portion 102 b in the printer main body 102. A discharge port (not shown) is formed in the step portion 104 immediately downstream of the discharge roller pair 130.

When a print signal is transmitted to the printer 100 from a personal computer (not shown), the surface of the photosensitive drum 105 uniformly charged by the main charger 106 is exposed by the laser scanning unit LSU, whereby an electrostatic latent image is formed. The formed electrostatic latent image is developed by the developing device 108 to become a toner image. This toner image is transferred by the transfer roller 110 to one side of the paper P conveyed from the paper feed cassette 116 at a predetermined timing. The sheet P on which the toner image has been transferred is transported along the transport path 114 to the fixing device 128 and is thermally fixed while passing through the fixing device 128. The paper P on which the toner image is fixed is discharged to the paper discharge tray 103 by the transport roller pair 129 and the discharge roller pair 130.

Next, the sheet member discharging apparatus 2 disposed in the printer 100 will be described. With reference to FIGS. 5 to 8, the sheet member discharge device 2 is stacked on the discharge roller pair 130, the discharge tray 103 on which the paper P discharged by the discharge roller pair 130 is stacked, and the discharge tray 103. A full load detection mechanism 4 is provided for detecting the height of the sheet P and outputting a signal when the height reaches a predetermined full load height Hmax.

The discharge roller pair 130 includes two driving rollers 132 and two driven rollers 134. The two driving rollers 132 are disposed so as to be integrally rotatable with the driven shaft 132A at an interval. The driven shaft 132A extends inside the stepped portion 104 of the protruding portion 102b in the printer main body 102 in a horizontal width direction (direction perpendicular to the paper surface in FIG. 1) perpendicular to the paper P discharge direction (conveyance direction) D. It is supported so that it can rotate freely. A driven gear (not shown) is disposed at one end of the driven shaft 132A so as to be integrally rotatable. The driven gear is connected to a drive source configured by an electric motor, for example, via a power transmission mechanism including the gear. Drive coupled (none shown). The two driven rollers 134 are arranged so as to be able to rotate integrally with the rotating shaft 134A at an interval. The rotating shaft 134A is supported so as to be rotatable and vertically movable so as to extend in parallel with an interval above the driven shaft 132A. Each of the driven rollers 134 is pressed against the corresponding driving roller 132 from above by its own weight or by biasing means (not shown) such as a spring. When each of the driving rollers 132 is rotationally driven by a driving source, each of the driven rollers 134 is rotated with each of the driving rollers 132.

The full load detection mechanism 4 is disposed in a central region of the rotation shaft 140 extending in the horizontal width direction above the discharge roller pair 130 and the rotation shaft 140 and is rotated by a discharge operation of the discharged paper P. And a detection member 142 that detects a predetermined full height Hmax of the paper P that is rotated around the moving shaft 140 and is stacked on the discharge tray 103. The rotating shaft 140 and the detection member 142 are integrally formed from an appropriate synthetic resin. The detection member 142 is positioned at a home position (a position indicated by a solid line in FIG. 6), which will be described later, and has a certain width and thickness in the horizontal width direction from the outer periphery of the rotating shaft 140 and is tangentially downward. It is formed so as to extend substantially vertically downward after extending while gently curving in the discharge direction.

A light shielding member 144 is integrally disposed at one end of the rotating shaft 140, and a photo sensor 146 is disposed at a position facing the light shielding member 144. The photosensor 146 is disposed in the protruding portion 102b (FIG. 1) of the printer main body 102. The position of the detection member 142 is detected by the photo sensor 146.

Between the right end region of the rotating shaft 140 in FIG. 5 and the locking portion 147 disposed in the protruding portion 102b (FIG. 1) of the printer main body 102, a torsion coil spring which is a detection member biasing means. 148 is disposed. One end of the torsion coil spring 148 is locked to the rotating shaft 140, and the other end is locked to the locking portion 147. The rotation shaft 140 is biased to rotate clockwise in FIGS. As a result, the detection member 142 is urged in a direction opposite to the discharge direction D at a home position (a position indicated by a solid line in FIGS. 6 and 8) that intersects the downstream side of the discharge roller pair 130 in the vertical direction. In the home position, the detection member 142 abuts the upper end 104S of the upright wall 104A that forms a part of the step 104 of the protrusion 102b (FIG. 1) of the printer main body 102 in the direction opposite to the discharge direction D. Is set by The upper end portion 104S of the upright wall 104A that constitutes a stopper that prevents the detection member 142 from rotating and is positioned at the home position has a driven shaft 132A in front of the driven shaft 132A of the discharge roller pair 130 in the discharge direction D side. However, a notch is formed in a portion where each of the driving rollers 132 exists, and interference with each of the driving rollers 132 is avoided. Of course, the stopper may be constituted by another member disposed on the protrusion 102b (FIG. 1) of the printer main body 102.

Referring to FIGS. 5, 7, and 9, presser members 150 that respectively hold both end portions of the paper P in the horizontal width direction on both sides of the center region of the rotation shaft 140 of the full load detection mechanism 4. However, it is supported so as to be relatively rotatable about the rotation shaft 140 by the discharging operation of the discharged paper P. Each of the pressing members 150 includes a cylindrical boss 152 that is fitted to the rotation shaft 140 so as to be relatively rotatable, and a pressing plate 154 that extends radially outward from the outer peripheral surface of the boss 152. Each of the presser plates 154 is positioned in a home position (a position indicated by a solid line in FIG. 7) described later, and has a certain width and thickness in the horizontal width direction from the outer peripheral portion of the corresponding boss 152 in the tangential direction. It is formed so as to extend downward while gently curving in the discharge direction and then extend substantially vertically downward.

Each boss 152 of the holding member 150 has a notch or a long hole extending in the axial direction with a predetermined circumferential width, in the embodiment, a notch 156 so as to extend from one end to the other end in the axial direction. Is formed. Stoppers 140 </ b> S are formed on both sides of the rotating shaft 140 so as to extend in the radial direction. Each of the stoppers 140 has a circumferential width that is narrower than the circumferential width of the notch 156 of the corresponding boss 152, and has a radial length that is approximately the same as the radial thickness of the corresponding boss 152. The boss 152 has an axial length that is shorter than the axial length of the notch 156. Each of the stoppers 140 is fitted into a notch or a long hole of the corresponding pressing member 152, and in the embodiment, an axial center region of the notch 156.

A torsion coil spring 158 (FIG. 5) that is a pressing member urging means is disposed between each boss 152 and the rotation shaft 140 of the pressing member 150. One end of each torsion coil spring 158 is locked to the rotating shaft 140, and the other end is locked to the corresponding boss 152. Each of the pressing members 150 is urged to rotate relative to the rotation shaft 140 in the clockwise direction in FIGS. 7 and 9. As a result, one side surface 156A in the circumferential direction of each notch 156 of the pressing member 150 is urged (pressed) in the circumferential direction by the corresponding torsion coil spring 158 to the corresponding stopper 140S. Each of the pressing members 150 is urged in a direction opposite to the discharge direction D at a home position (a position indicated by a solid line in FIG. 7) that intersects the downstream side of the discharge roller pair 130 in the vertical direction. A circumferential clearance of a predetermined angle is formed between the other circumferential surface 156B of each notch 156 of the pressing member 150 and the corresponding stopper 140S. Each presser plate 154 of the presser member 150 is positioned with a gap with respect to the upper end portion 104S of the upright wall 104A. In the illustrated embodiment, the width of each presser plate 154 is formed wider than the width of the detection member 142 so that both end portions of the paper P of different sizes can be pressed (the paper P is the horizontal plate). Transported with reference to the center in the width direction). In addition, the heights of the lower ends of the detection member 142 and the presser plate 154 at the home position are substantially the same. In FIG. 9, the torsion coil springs 148 and 158, the photosensor 146, and the locking portion 147 are not shown for simplification of the drawing. 2 to 4 show a part of the sheet member discharging apparatus 2.

5 to 8, each holding plate 154 of the holding member 150 is independent of the detection member 142 until the stacking height of the sheets P on the discharge tray 103 reaches a predetermined height H1. Although it rotates, it is configured to rotate integrally with the detection member 142 after the stacking height exceeds a predetermined height H1. The predetermined height H1 is lower than a predetermined full height (height Hmax). In such a configuration, when the paper P is discharged in a state where both side edges are curled, a signal is output in a state where the stacked paper P does not reach a predetermined full height (height Hmax), and a predetermined full load is obtained. It is possible to prevent a malfunction that erroneously detects the state.

In the embodiment, the spring force that is the urging force of the torsion coil spring 148 that is the detection member urging means is set to be larger than the sum of the spring forces that are the urging forces of the torsion coil springs 158 that are the pressing member urging means. Has been. When the paper P is discharged in a state where both side edges are curled, at the initial stage of discharge, the pressing force of the pressing member 154 acting on both side edges of the paper P is weakened (each of the torsion coil springs 158). By pressing with a spring force), troubles due to excessive pressing of both end portions of the paper P are prevented, and smooth discharge is possible. At this time, even if both end portions of the paper P discharged to the discharge tray 103 are curled (even if the paper jumps up), there is no problem because the number of stacked sheets is small. When the number of stacked sheets on the discharge tray 103 increases, it is necessary to increase the pressing force in order to prevent the curled state. According to the present invention, after the stacking height exceeds the predetermined height H1, it is configured to switch to the total spring force of each of the torsion coil springs 148 and 158 so as to press both side ends of the paper P. The predetermined full load error detection described above is prevented. Moreover, since the setting of the pressing force (load) at both side ends and the center of the paper P can be set appropriately, the paper P can be prevented from being rounded and good stockability can be secured. FIG. 10 shows a state where the height of the paper P discharged to the discharge tray 103 has reached a predetermined full height (height Hmax).

According to the present invention, each of the torsion coil springs 158 as the pressing member urging means is independently rotated with respect to the detection member 142 from the home position to a predetermined angle by the discharging operation of the discharged paper P. After the predetermined angle is exceeded, the detection member 142 is configured to rotate integrally. This configuration makes it possible to achieve the above-described effects easily in practice.

According to the present invention, each of the pressing members 150 includes a cylindrical boss 152 that is fitted to the rotation shaft 140 so as to be relatively rotatable, and a pressing plate 154 that extends radially outward from the outer peripheral surface of the boss 152. Each boss 152 of the pressing member 150 is formed with a notch 156 or an elongated hole extending in the axial direction with a predetermined circumferential width. 140S is formed so as to extend in the radial direction, and each of the stoppers 140A of the rotating shaft 140 is fitted into each notch 156 or the long hole of the corresponding pressing member 150, and each notch 156 of the pressing member 150 is fitted. Alternatively, one side surface 156A (FIG. 9) in the circumferential direction of the elongated hole is biased in the circumferential direction by the torsion coil spring 158 to the corresponding stopper 140S, and the circumferential direction of each notch 156 or the elongated hole of the pressing member 150 And the other side 156B (FIG. 9), between the corresponding stop 140S, the predetermined angle in the circumferential direction gap is formed, as configured. This configuration makes it possible to achieve the above-described effects easily in practice.

The printer 100 includes an image forming unit that forms an image on the paper P and a sheet member discharge device 2 that discharges the paper P on which the image is formed by the image forming unit. Even when discharged in a curled state, predetermined full load detection is possible.

1 is a schematic configuration diagram illustrating an embodiment of a printer including a sheet member discharging apparatus configured according to the present invention. FIG. 2 is a perspective view of the printer shown in FIG. 1. FIG. 3 is an enlarged perspective view showing a part of the printer shown in FIG. 2 (a part provided with a sheet member discharging device). FIG. 4 is an enlarged perspective view of a part of the printer shown in FIG. 3 viewed from another angle. FIG. 2 is a schematic front view of the sheet member discharging device provided in the printer shown in FIG. 1 as viewed from the downstream in the sheet member discharging direction toward the upstream. It is AA arrow sectional drawing of FIG. It is BB arrow sectional drawing of FIG. It is CC sectional view taken on the line of FIG. FIG. 6 is a schematic perspective view showing a part of the full load detection mechanism shown in FIG. 5. It is sectional drawing which shows the other operation state (full load detection state) of FIG.

Explanation of symbols

2: Sheet member discharge device 4: Full load detection mechanism 100: Printer 103: Discharge tray 130: Discharge roller pair 140: Rotating shaft 142: Detection member 150: Pressing member P: Paper (sheet member)

Claims (5)

A discharge means for discharging the sheet member; a discharge tray on which the sheet member discharged by the discharge means is stacked; and a height of the sheet member stacked on the discharge tray is detected and the height reaches a full load height. A full load detection mechanism that outputs a signal, and the full load detection mechanism is integrated with a rotation shaft extending in the horizontal width direction perpendicular to the discharge direction of the sheet member and a central region of the rotation shaft. A sheet member discharge device comprising: a detection member that is disposed and is rotated about a rotation shaft by a discharge operation of the discharged sheet member and detects a full height of the sheet member stacked on the discharge tray. In the device
In both side areas sandwiching the central area of the rotation shaft, the holding members that respectively hold the both end portions of the sheet member in the horizontal width direction are relatively rotated around the rotation axis by the discharging operation of the discharged sheet member. Supported as possible,
The holding member rotates independently with respect to the detection member until the stacking height of the sheet members on the discharge tray reaches a predetermined height, but after the stacking height exceeds the predetermined height, the detection member Configured to rotate integrally with
The sheet | seat member discharging apparatus characterized by the above-mentioned. The detection member urging means for urging the detection member in a direction opposite to the discharge direction at the home position that intersects the downstream side of the discharge means in the vertical direction, and the holding member respectively, and the downstream side of the discharge means in the vertical direction A pressing member urging means for urging in a direction opposite to the discharging direction at a home position intersecting with
The sheet member discharging apparatus according to claim 1, wherein the urging force of the detection member urging means is set to be larger than the sum of the urging forces of the pressing member urging means. Each of the pressing member urging means rotates independently from the home position up to a predetermined angle by the discharging operation of the discharged sheet member, but after the predetermined angle is exceeded, it is integrated with the detection member. The sheet member discharging apparatus according to claim 2, wherein the sheet member discharging apparatus rotates. Each of the presser members includes a cylindrical boss that is fitted to the rotary shaft so as to be relatively rotatable, and a presser plate that extends radially outward from the outer peripheral surface of the boss,
Each boss of the presser member is formed with a notch or an elongated hole extending in the axial direction with a predetermined circumferential width, and a stopper is formed in each side region of the rotating shaft so as to extend in the radial direction. Each of the stoppers of the rotation shaft is fitted into a notch or a slot of the corresponding pressing member, and one side surface in the circumferential direction of each of the pressing member is pressed by the pressing member urging means. A circumferential clearance of the predetermined angle is formed between each notch or each other side surface of the elongated hole in the circumferential direction and the corresponding stopper that is biased in the circumferential direction by the corresponding stopper. The sheet member discharging apparatus according to claim 3. An image forming apparatus comprising: an image forming unit that forms an image on a sheet member; and a sheet member discharging device that discharges a sheet member on which an image is formed by the image forming unit.
The sheet member discharge device is configured of the sheet member discharge device according to any one of claims 1 to 4.
An image forming apparatus.

Images