JP4127528B2 - Paper discharge roller and paper discharge device using the same - Google Patents

Description

  The present invention relates to a paper discharge roller (hereinafter simply abbreviated as “roller”) and a paper discharge device (hereinafter simply abbreviated as “discharge device”) using the same, and more specifically, copying. The present invention relates to a roller used in an image forming apparatus such as a printer, a printer, or a facsimile machine, and a discharge device using the roller.

  For example, a roller 6 as shown in FIG. 6 has been conventionally used in order to properly align the paper discharged onto the paper discharge tray. The roller 6 of FIG. 6 has a shaft portion 13 formed at the center of a cylindrical roller body 11, and a large diameter portion 14 formed by gradually increasing the diameter toward the outer side in the axial direction at both ends of the roller body 11. Is integrally formed. Then, as shown in FIG. 7, the roller 6 is pressed against the discharge roller 2 made of an elastic member to be driven by the rotation of the discharge roller 2, and the paper P is sandwiched between the discharge roller 2 and the roller 6, The sheet P was discharged on the sheet discharge tray with a so-called waist. However, when such a roller 6 is used, depending on the type of paper, streaks may enter the paper P when it is sandwiched between the discharge roller 2 and the roller 6. In addition, when the discharge speed of the paper P is slow, after the paper P comes out of the nipping between the discharge roller 2 and the roller 6, the rear end of the paper P stays on the discharge path, and the subsequent paper is smoothly discharged. This hinders the alignment of the paper on the paper discharge tray.

For this reason, for example, a roller 7 as shown in FIG. 8 has been proposed. The roller 7 is formed by forming a plurality of protrusions 12a and 12b having the same shape on both ends of a cylindrical roller body 11. The plurality of protrusions 12a and 12b are formed at an equal angle in the circumferential direction so that there is no phase difference in the formation cycle between both end sides. According to such a roller 7, streaks are prevented from entering the paper P when it is sandwiched between the discharge roller 2 and the roller 7, and the rear end of the paper P is pushed out by the protrusions 12 a and 12 b of the roller 7. This effectively prevents the trailing edge of the sheet from remaining on the discharge path.
JP 2001-48392 A ((0031) stage to (0035) stage, FIG. 4) JP 2001-39598 A ((0002) stage to (0005) stage, FIGS. 8 to 11)

  However, if the projections 12a and 12b to be formed are too high, the paper P may vibrate little by little and noise may be generated. On the other hand, if the height of the protrusions 12a and 12b is too low, the paper P cannot be seated and the alignment of the paper on the paper discharge tray is disturbed. For this reason, it is necessary to control the height of the protrusions 12a and 12b formed on the roller 7 with high precision. However, increasing the dimensional accuracy of the roller 7 produced by molding is accompanied by technical difficulties and costs. Directly connected to up.

  The present invention has been made in view of such a conventional problem, and the object of the present invention is to hold the paper without streaking when the paper is sandwiched between the discharge roller and the roller. The paper discharge roller can be used to prevent the trailing edge of the paper from staying on the discharge path and to properly align the paper on the paper discharge tray without causing vibration and noise. And providing a paper discharge device.

  In order to achieve the above object, in the paper discharge roller of the present invention, a plurality of protrusions are formed in the circumferential direction on both ends of the cylindrical roller body, and formed on one end side when viewed from the axial direction of the roller body. At least part of the protrusion formed on the other end side is exposed between the protrusions.

  Here, in order to reliably push out the trailing edge of the sheet to the paper discharge tray, it is preferable that the plurality of protrusions have the same shape and are formed at equal angles in the circumferential direction on both ends of the roller body, and further on both ends. It is preferable that the phase difference between the formation periods of the protrusions is ½ period.

  The paper discharge device of the present invention comprises a discharge roller fixed to a rotational drive shaft arranged in the paper width direction, and a paper discharge roller that is driven in pressure contact with the discharge roller, the discharge roller and the paper The paper is sandwiched and discharged by a discharge roller, and the paper discharge roller described above is used as the paper discharge roller.

  In the paper discharge roller and the paper discharge device of the present invention, a plurality of protrusions are formed in the circumferential direction on both ends of the cylindrical roller body, so that the trailing edge of the paper is directed toward the discharge tray at the inclined portion of the protrusion. The sheet can be pushed out and the trailing edge of the sheet can be prevented from staying on the discharge path. In addition, when viewed from the axial direction of the roller body, at least part of the protrusion formed on the other end side is exposed between the protrusion formed on one end side, so that the protrusion Without strictly adjusting the height, the sheet can be seated and at the same time the generation of minute vibrations of the sheet due to the protrusions can be suppressed and noise due to vibration can be prevented.

  If the plurality of protrusions have the same shape, are formed at equal angles in the circumferential direction on both ends of the roller body, and the phase difference of the protrusion formation period between both ends is ½, the trailing edge of the paper is It can be reliably pushed out to the paper discharge tray.

  Hereinafter, the roller and the discharge device of the present invention will be described with reference to the drawings. The present invention is not limited to these embodiments.

  In FIG. 1, the perspective view which shows one Embodiment of the discharge device of this invention is shown. In the discharge device of FIG. 1, four discharge rollers 2 are fixed at substantially equal intervals in the axial direction to a rotary drive shaft 3 that is arranged in the paper width direction and is rotated by a motor (not shown). At least the outer surface of the discharge roller 2 has elasticity.

  On the other hand, a roller 1 is disposed at a position opposite to the lower side of each discharge roller 2. FIG. 2 shows a perspective view of the roller 1. The roller 1 is formed by integrally forming a cylindrical roller body 11, a shaft portion 13 formed at the center thereof, and a plurality of protrusions 12 a and 12 b formed on the outer peripheral surfaces of both ends of the roller body 11. . FIG. 3 is a diagram showing how the roller protrusions 12a and 12b in FIG. 2 are formed. FIGS. 4A and 4B are views showing how the protrusions 12a and 12b on the left end side and the right end side of the roller 1 are formed. All the protrusions 12a and 12b formed on the end side of the roller body 11 have the same shape, and are substantially trapezoidal in a side view. Eight protrusions 12a and 12b are formed on each of both end sides in the circumferential direction with a period θ = 45 °.

  The left side view of the roller 1 is shown in FIG. In this drawing, for easy understanding, the left end side protrusion 12a is indicated by a solid line, and the right end side protrusion 12b is indicated by a broken line. As described above, the left end protrusion 12a and the right end protrusion 12b are formed in the circumferential direction at a period θ = 45 ° in the same manner, and the formation period of the left end protrusion 12a and the right end protrusion 12b is the same. The phase difference is ½ period (22.5 °). As a result, as is clear from FIG. 9C, the right end side protrusion 12b is positioned between the left end side protrusion 12a and the protrusion 12a.

  Returning to FIG. 1, the roller 1 is rotatably attached to the frame 5 by the shaft portion 13 of the roller 1 being rotatably supported by the frame body 5 of the discharge device. Then, at least one of the frame body 5 and the rotary drive shaft 3 supporting the shaft portion 13 is urged in a direction in which both approach each other by urging means (not shown). Thereby, the roller body 11 and the discharge roller 2 are in pressure contact. Note that the number of the discharge rollers 2 and the rollers 1 to be disposed is not limited, and the position in the axial direction of the discharge rollers 2 and the rollers 1 is not particularly limited as long as the paper P passes through. In the discharge device of FIG. 1, since the paper P passes through the central portion in the width direction, the discharge rollers 2 and the rollers 1 are arranged symmetrically with respect to the center in the width direction, but the paper P is set with reference to one side in the width direction. When the toner passes, the discharge roller 2 and the roller 1 may be arranged with the one side as a reference.

  When the rotation drive shaft 3 rotates by driving a motor (not shown), the discharge roller 2 fixed to the rotation drive shaft 3 rotates, and at the same time, the roller 1 pressed against the discharge roller 2 also rotates according to the rotation of the discharge roller 2. To do. The paper P is sandwiched between the discharge roller 2 and the roller body 11 and is discharged from the image forming apparatus on the left back side in FIG. 1 onto the paper discharge tray 4 on the right front side.

  At this time, as shown in FIG. 3C, when viewed from the axial direction of the roller body 11, it is formed on the other end side between the protrusion 12a formed on one end side of the roller and the protrusion 12a. Since the roller 1 is configured so that the projected protrusion 12b is exposed, even if the height of the protrusions 12a and 12b is not accurately adjusted, the paper P does not get streaks and has a waist. In this state, the paper P can be discharged. Even in a device with a slow discharge speed, the trailing edge of the paper P can be pushed out by the inclined portions of the protrusions 12a and 12b, so that the trailing edge of the paper does not stay on the discharge path.

  In FIG. 4, the side view which shows other embodiment of the roller of this invention is shown. The roller 1 'in FIG. 4 has four substantially trapezoidal protrusions 12a formed at every 90 ° in the circumferential direction on the left end side of the roller body 11 (FIG. 4A), and on the right end side. Eight substantially trapezoidal protrusions 12b are formed every 45 ° in the circumferential direction ((b) in the figure). A left side view of the roller 1 ′ is shown in FIG. As can be understood from this figure, in the roller 1 ′ in FIG. 4, two right-end projections 12 b are exposed between the left-end projection 12 a and the projection 12 a in the left side view. Even with the roller 1 ′ having such a configuration, the above-described effect is exhibited.

  In FIG. 5, the side view which shows other embodiment of the roller of this invention is shown. 5 is a case where the shape of the protrusions formed on the left and right end sides of the roller body 11 is different. The left end side of the roller body 11 has four substantially trapezoidal shapes every 90 ° in the circumferential direction. One protrusion 12a is formed (FIG. 1A), and four protrusions 12c that are long in the circumferential direction are formed on the right end side every 90 ° in the circumferential direction (FIG. 1B). A left side view of the roller 1 ″ is shown in FIG. As understood from this figure, in the roller 1 ″ in FIG. 5, the right end protrusion 12c is exposed so as to fill a long space between the left end protrusion 12a and the protrusion 12a in the left side view. Even with the roller 1 ″ having such a configuration, the above-described effect can be obtained.

  The protrusions formed on the left and right end sides of the roller body have protrusions on one end side so as to fill as much space as possible between the protrusions formed on one end side when viewed from the axial direction. Is desirable. More preferably, as shown in FIG. 3, protrusions having the same shape are formed at equal angles in the circumferential direction, and the phase difference between the protrusion formation periods between both ends is set to ½ period. The shape of the protrusion is preferably substantially trapezoidal in a side view, and the upper side length is preferably 2πr / (total number of protrusions) (where r is the distance from the center of the axis to the upper surface of the protrusion). The height from the main body is preferably about 1 to 2 mm.

  The roller of the present invention can be produced by a conventionally known production method, and it is recommended to produce it by die molding in consideration of productivity and cost. There is no particular limitation on the material of the roller, but it needs to be plastic when it is produced by molding, and polyacetal is preferred among plastics in view of wear and slipperiness.

It is a perspective view which shows an example of the paper conveying apparatus of this invention. It is a perspective view showing an example of a paper discharge roller of the present invention. FIG. 3 is a side view showing a formation state of protrusions of the paper discharge roller of FIG. 2. It is a side view which shows the other example of the sheet | seat discharge roller of this invention. It is a side view which shows the further another example of the roller for paper discharge | emission of this invention. It is a perspective view which shows an example of the conventional paper discharge roller. It is a front view showing a conventional paper discharge roller and a paper discharge device. It is a perspective view which shows the other example of the conventional paper discharge roller.

Explanation of symbols

1, 1 ', 1 "paper discharge roller 2 discharge roller 3 rotation drive shaft 4 discharge tray 11 roller body 12a, 12b, 12c protrusion 13 shaft portion 14 large diameter portion

Claims (4)

A plurality of protrusions are formed in the circumferential direction on both ends of the cylindrical roller body, and the other is formed so as to fill a space between the protrusions formed on one end side when viewed from the axial direction of the roller body. paper discharge roller, wherein the exposed end formed on side collision of the Kiga.   The paper discharge roller according to claim 1, wherein the plurality of protrusions have the same shape, and are formed at equal angles in the circumferential direction on both ends of the roller body.   The paper discharge roller according to claim 2, wherein the phase difference in the formation period of the protrusions between both ends is ½ period. A discharge roller fixed to a rotation drive shaft disposed in the paper width direction, and a paper discharge roller that is driven by being pressed against the discharge roller, and holds the paper between the discharge roller and the paper discharge roller In the paper discharge device that discharges
A paper discharge device using the paper discharge roller according to claim 1 as the paper discharge roller.

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