Patent Grant
10906766
The present invention relates to a sheet discharging apparatus discharging a sheet and an image reading apparatus including the sheet discharging apparatus.
Generally, in image forming apparatuses such as a copying machine and a facsimile machine, an image forming apparatus is known that includes a finisher connected to an image forming apparatus body, and discharging a sheet on which an image is formed in the image forming apparatus body. Conventionally, the finisher including a sample tray has been proposed. The sample tray is inclined such that the downstream in a sheet conveying direction becomes higher and the upstream with respect to the sheet conveying direction becomes lower. The trailing edge of a sheet discharged to the sample tray is received by a side part of a finisher body (see U.S. Pat. No. 6,505,829). Additionally, this finisher includes an earth (or ground) piece at the side part of the finisher body. The earth piece abuts the trailing edge of the discharged sheet, and performs static elimination of the static electricity of the sheet charged while being conveyed within the finisher. In this manner, the stacking failure of sheets due to floating of the sheets that is caused by repulsion between the sheets due to static electricity is prevented.
However, in a sheet processing apparatus described in U.S. Pat. No. 6,505,829, there was a possibility that the trailing edge of the discharged sheet did not reach the side part of the finisher body, and the sheet did not abut the earth piece in the case where the inclination of the sample tray was shallow due to the limitations of a body size, etc. Therefore, there has been a problem that the stacking failure of sheets occurs since a stable static elimination effect on the sheets discharged to the sample tray is not obtained.
Thus, the present invention provides a sheet discharging apparatus that exhibits a stable static elimination effect, and that can reduce the stacking failure of sheets, and provides an image reading apparatus including this sheet discharging apparatus.
A sheet discharging apparatus according to one example of the present invention, includes:
a discharge portion discharging a sheet in a discharge direction;
a sheet supporting portion including a support surface which supports a lower surface of the sheet discharged from the discharge portion; and
a conductive portion which is electrically conductive and connected to a ground potential,
wherein the conductive portion is provided at the support surface.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
[General Configuration]
First, a first embodiment according to the present invention will be described. A printer 1 as an image forming apparatus according to the first embodiment is an electrophotography type laser beam printer. As illustrated in
The printer 1 includes, inside of the image forming apparatus body 1A, an image forming unit 1B that forms an image on a sheet P, which is a recording medium on which the image is not formed, and a fixing portion 20 that fixes the image to the sheet P, etc. A sheet discharging tray 23 is provided in a sheet discharging space S1 formed between the image reading apparatus 2 and the image forming apparatus body 1A. Additionally, a sheet feeding portion 30 that feeds the sheet P to the image forming unit 1B is provided in the image forming apparatus body 1A. The sheet feeding portion 30 includes one or more (four in this embodiment) sheet feeders 31, 32, 33 and 34 arranged at the lower part of the image forming apparatus body 1A, and a manual feeder (not shown).
The image forming unit 1B has a so-called four-drum full-color configuration that includes a laser scanner 10, four process cartridges 1a, 1b, 1c and 1d, and an intermediate transfer unit 1C. These cartridges form toner images of yellow, magenta, cyan and black, respectively. Each of the process cartridges 1a, 1b, 1c and 1d includes a photosensitive drum 12, a charging device 13, a developing device 14, and a cleaner (not shown). Further, a toner cartridge 15 housing the toners of respective colors is removably attached to the image forming apparatus body 1A. The toner cartridge 15 is attached above the image forming unit 1B.
The intermediate transfer unit 1C includes an intermediate transfer belt 16 wrapped around a driving roller 16a and a tension roller 16b, etc., and is arranged above the four process cartridges 1a, 1b, 1c and 1d. The intermediate transfer belt 16 is rotated counterclockwise in
In each of the above-mentioned process cartridges 1a, 1b, 1c and 1d, the toner image of each color charged to a negative polarity is formed by supplying a toner from the developing device 14 after an electrostatic latent image is drawn on the surface of photosensitive drum 12 drawn by the laser scanner 10. Further, the surface of each photosensitive drum 12 is charged in advance by the charging device 13 before laser is irradiated on the photosensitive drum 12 by the laser scanner 10. A full-color toner image is formed on the intermediate transfer belt 16 by performing the multiple transfer (primary transfer) of these toner images to the intermediate transfer belt 16 by applying a transfer bias voltage of positive polarity to the primary transfer rollers 17.
In parallel to such a formation process of the toner image, the sheet P fed from the sheet feeding portion 30 is conveyed toward a registration roller pair 18, and the skew is corrected by the registration roller pair 18. The registration roller pair 18 conveys the sheet P to a secondary transfer portion formed between the intermediate transfer belt 16 and the secondary transfer roller 19 according to the transfer timing of the full-color toner image formed on the intermediate transfer belt 16. The toner image carried by the intermediate transfer belt 16 is secondarily transferred to the sheet P by applying the transfer bias voltage of positive polarity to the secondary transfer roller 19.
When the sheet P on which the toner image is transferred is heated and pressurized in the fixing portion 20, the toner image is fixed to the sheet P as a color image. The sheet P on which the image was fixed is discharged to a sheet discharging tray 23 by sheet discharge roller pairs 25a and 25b, and is stacked. Further, in the case of forming an image on both surfaces of the sheet P, the sheet P having passed the fixing portion 20 is switched back by a reversing roller pair 26 that is provided in a reversed conveying portion 1D, and can perform forward rotation/reverse rotation. Then, when the sheet P is conveyed again to the image forming unit 1B via a re-conveying passage R1, an image is formed on the rear surface of the sheet P, the sheet P is discharged to the sheet discharging tray 23, and double-side printing is completed.
[Image Reading Apparatus]
As illustrated in
The reader portion 2B includes an optical box 159 as a reading unit reading the image of the document D, a platen glass 161, and the document glass plate 3 arranged along with the platen glass 161 on the upper surface of the reader portion 2B. The optical box 159 includes a lamp 152 irradiating the document D, and a mirror 153 guiding the reflected light from the document D. Additionally, the optical box 159 includes a lens 157 focusing the reflected light guided by the mirror 153, and a charge-coupled device 158 (hereinafter referred to as the CCD) that performs photoelectric conversion of the focused reflected light, and outputs the light as image information.
The optical box 159 is connected to a wire (not shown), and can perform reciprocating movement parallel to the document glass plate 3 by the driving of a motor (not shown). The optical box 159 performs the reciprocating movement between a reading position illustrated in
The ADF 2A includes a document feeder 102, a registration roller pair 146, conveyance guide 131, and a first lead roller pair 132. Additionally, the ADF 2A includes a second lead roller pair 133, a rear surface platen glass 171, a back side optical box 172 as a reading unit, and a document discharge apparatus 103 as a sheet discharging apparatus. The details of the ADF 2A are described later.
Next, the operation at the time of reading an image by the image reading apparatus 2 is described by taking as an example the case where the image is read by the document flow reading. When a control unit (not shown) receives an image reading signal of the document flow reading, the document D stacked on a document tray 4 is fed by the document feeder 102 described later. The positions of the end portions of the document D in a width direction orthogonal to the moving direction of the optical box 159 are regulated by a pair of width direction regulation plates 119. The skew of the document D is corrected by the registration roller pair 146, and the conveying direction of the document D is changed by the conveyance guide 131 that is curved, and the document D is conveyed toward the platen glass 161 by the first lead roller pair 132.
On this occasion, the optical box 159 is located in the reading position, which is the position below the platen glass 161 as illustrated in
After the image on the front surface of the document D is read by the optical box 159, the document D is conveyed by the second lead roller pair 133 toward the rear surface platen glass 171. As for the document D conveyed on the rear surface platen glass 171, an image on the rear surface is read by the back side optical box 172 as in the front surface. Then, after the images on the front surface and the rear surface of the document D are read, the document D is discharged by the document discharge apparatus 103 to a document discharging tray 110 described later. The document discharging tray 110 is arranged under the document tray 4 in the vertical direction, and the discharged document D is placed on the document discharging tray 110.
Next, the details of the ADF 2A are described. The document feeder 102 includes the document tray 4, the width direction regulation plates 119, a document detection lever 109, a feed cover 111, a shutter 113, a pickup roller 105, a separation conveyance roller 108, separation pad 106, and a conveying roller pair 147.
The document tray 4 on which the document D is placed is downwardly inclined as it proceeds to the downstream where the document D is conveyed. Additionally, the document tray 4 includes a pair of the width direction regulation plates 119 sliding in the width direction. The width direction regulation plates 119 can slide in the width direction of the document such that the interval distance between the width direction regulation plates 119 can be adjusted within the limits of the size of the document that can be placed on document tray 4, i.e., the size of the document that can be read by the image reading apparatus 2. The width direction regulation plates 119 can control the movement of the document D in the width direction by being slid according to the width of the document D placed on the document tray 4.
The document detection lever 109 is arranged downstream of the document tray 4 in the conveying direction of the document D. The document detection lever 109 is rotatably supported about a shaft 109a. Additionally, the document feeder 102 includes a document sensor (not shown) formed by a photo interrupter. In the state where the document D is not placed on the document tray 4, the document sensor is maintained in a shaded state where the document sensor is shaded by the document detection lever 109. When the document D is placed on the document tray 4, the document detection lever 109 is pressed by the document D, and the document detection lever 109 is rotated about the shaft 109a in the direction of an arrow X in
A shutter 113 and a pickup roller 105 that is supported by a support arm (not shown) such that the pickup roller 105 can go up and down are arranged in the downstream of the document detection lever 109 in the conveying direction of the document D. The shutter 113 is rotatably supported about a rotation shaft 113a. When the pickup roller 105 is located at the standby position indicated by a continuous line in
Next, the positional relationship between the pickup roller 105 and the shutter 113 is described. The pickup roller 105 is standing by at the standby position close to the feed cover 111, such that the pickup roller 105 does not disturb the document placement when a user places the document D on the document tray 4. When the document D is placed, the tip of the document D passes under the pickup roller 105, pushes away the document detection lever 109 upward, and is held at the position at which the tip is made to abut the shutter 113.
When the feeding of the document D is started, the pickup roller 105 descends to the feed position, and abuts the top surface of the document D. On this occasion, the shutter 113 is located at the evacuation position, and releases the damming of the document D. Then, by the rotation of the pickup roller 105, the document D passes the shutter 113, and is conveyed toward the separation conveyance roller 108 and the separation pad 106. The separation pad 106 is arranged to face the separation conveyance roller 108, and is pressed against the separation conveyance roller 108. The separation pad 106 and the separation conveyance roller 108 are configured such that, when a plurality of documents D are simultaneously supplied by the pickup roller 105, the supplied documents D are separated by the separation pad 106 and the separation conveyance roller 108, and one document is fed at a time.
Each one of the documents D separated by the separation pad 106 and the separation conveyance roller 108 is conveyed by the conveying roller pair 147, and is conveyed along the conveyance guide 131 forming the conveying path of the document D while the skew is corrected by the registration roller pair 146. The document D is conveyed by the first lead roller pair 132 toward the platen glass 161, an image on the rear surface is read by the back side optical box 172, and thereafter, the document D is conveyed to the document discharge apparatus 103 by the second lead roller pair 133.
As illustrated in
[Details of Document Discharge Apparatus]
Hereinafter, referring to
The document D conveyed by the second lead roller pair 133 (see
As illustrated in
The extension trays 123 and 124 are arranged in the downstream end of the document discharging tray 110 in the document discharge direction Y, and are configured to be slidable with respect to the document discharging tray 110 along the support surface 122. The extension trays 123 and 124 will be in the state where the extension trays 123 and 124 can support the discharged document D by being slid in the document discharge direction Y, even when the length of the discharged document D in the conveying direction is longer than the document discharging tray 110. Additionally, when the length of the discharged document D in the conveying direction is smaller than the document discharging tray 110, the extension trays 123 and 124 are slid in the direction opposite to the document discharge direction Y, and can be stored in the document discharging tray 110. In this manner, the image reading apparatus 2 enables the suppression of the length of the image reading apparatus 2 in the document discharge direction Y, while enabling the reading of a document having a long length in the conveying direction.
The support surface 122 includes an inclined surface 122b as the first surface that inclines upward toward the downstream of the document discharge direction Y. Additionally, the support surface 122 includes a parallel surface 122a as the second surface that is substantially parallel to the document glass plate 3, and that has a smaller angle than the inclined surface 122b with respect to a horizontal plane. Further, in this embodiment, the parallel surface 122a and the document glass plate 3 are provided parallel to a horizontal direction. The parallel surface 122a is arranged upstream of the inclined surface 122b in the document discharge direction Y, and the upstream end is located under the document discharge roller pairs 118, and the downstream end is connected to the inclined surface 122b with a gentle curve. The upstream end wall 121 is provided upstream of the support surface 122 in the document discharge direction Y, and restricts the trailing edge of the discharged document D. The upstream end wall 121 is formed to rise upward toward the document discharge roller pairs 118 from the upstream end of the parallel surface 122a in the document discharge direction Y.
As illustrated in
Additionally, when the angle of the inclined surface 122b with respect to the horizontal plane is small, it becomes difficult for the discharged document D to reach the upstream end wall 121 and the matching amount increases. Thus, it is desirable that the angle of the inclined surface 122b with respect to the horizontal plane is sufficiently large. Additionally, when the length of the document discharge space S2 in the up-and-down direction is small, in the case where the discharged document is curved upward, discharge failure tends to occur. For example, the document D is caught in the lower part of the document tray 4. Therefore, it is desirable for the upstream end of the inclined surface 122b to be arranged sufficiently distant from the document tray 4 in the up-and-down direction. However, in recent years, it is required that the size of the ADF 2A is reduced in the up-and-down direction, and the angle formed between the horizontal plane and the inclined surface 122b is set to be as small as possible, while considering the influence on the matching amount, the influence on the discharge failure of a document, etc.
The discharge sensor flag 112 is supported by the document discharging tray 110 so as to be rotatable about an axis extending in the width direction, and is urged toward a protruding position protruding from the parallel surface 122a by a spring (not shown). Additionally, the discharge sensor flag 112 is arranged near the center of the parallel surface 122a in the width direction. Specifically, the discharge sensor flag 112 is arranged to protrude from the parallel surface 122a between the far end and the close end of the document D when located at the protruding position, in the state where the document D having the minimum size that can be read by the image reading apparatus 2 is located at the center in the width direction. In this manner, the width direction position of the discharge sensor flag 112 is set to the position at which the discharge sensor flag 112 stably abuts the lower surface of the document D in the state where the document D rests, even when the document D having the minimum size that can be read by the image reading apparatus 2, i.e., the document D having the minimum size that can be supported by the document discharging tray 110, is discharged. Note that, in the following description, a document having the minimum size that can be supported by the document discharging tray 110 is simply called a minimum size document.
Additionally, when located at the protruding position, the discharge sensor flag 112 is arranged to protrude from the parallel surface 122a at a position distant from the upstream end wall 121 in the downstream side. In this manner, the position of the discharge sensor flag 112 in the document discharge direction Y is set to the position at which the discharge sensor flag 112 stably abuts the lower surface of the document D in the state where the document D rests, even when the discharged document D does not reach the upstream end wall 121. Further, the discharge sensor flag 112 is arranged upstream of the middle L1 of the support surface 122 in the document discharge direction Y. Specifically, the discharge sensor flag 112 is arranged to protrude from the parallel surface 122a in the upstream of the leading edge of the document D in the document discharge direction Y when located at the protruding position, in the state where the minimum size document D is discharged, abuts and rests on the upstream end wall 121. In this manner, the position of the discharge sensor flag 112 in the document discharge direction Y is set to the position at which the discharge sensor flag 112 stably abuts the lower surface of the document D in the state where the document D rests, even when the minimum size document D is discharged. When the document D is discharged to the discharge space S2, the discharge sensor flag 112 abuts the lower surface of the document D, is rotated downward by the weight of the document D, and is moved to a retracted position as a lower position at which the protruding amount from the parallel surface 122a is smaller than that at the protruding position.
The discharge sensor 117 is formed by a photo interrupter, and is maintained in the shaded state where the light is shaded by the discharge sensor flag 112 in the state where the lower surface of the discharged document D is not abutting the discharge sensor flag 112. The discharge sensor 117 is pressed by the lower surface of the document D discharged to the discharge space S2, transitions to the translucent state where the light of the discharge sensor 117 is translucent based on the rotation of the discharge sensor flag 112, and outputs a detection signal detecting that the document D has been discharged to the discharge space S2. In this manner, the discharge sensor 117 is detecting whether or not a document that a user has not collected is on the document discharging tray 110. Additionally, the discharge sensor 117 also detects that all of the discharged documents have been collected from the document discharging tray 110 when the discharge sensor 117 transitions from the translucent state to the shaded state. Additionally, when the discharge sensor 117 has detected that an uncollected document is on the document discharging tray 110, an LED lamp (not shown) provided in the ADF 2A is lit, so as to report to the user that the uncollected document is on the document discharging tray 110.
Next, the static elimination of the document D is described. The surface of the document D is charged by sliding friction with the conveyance guide 131, various rollers, the separation pad 106, etc. that are forming the conveying path inside the ADF 2A. Especially, when a plurality of documents are continuously discharged in a low humidity environment, if a document discharged next overlaps with a document discharged previously and supported by the support surface 122, the repulsion occurs between the charged documents due to static electricity, and it becomes difficult for the document discharged next to fall. When discharging of the document is continued in such a state, discharge failure may occur. For example, the ends of the documents may abut to each other to cause conveyance jam, and the discharged document may be folded. Therefore, the image reading apparatus 2 of the present embodiment includes, as a static elimination unit of the discharged document D, the static eliminating needle 114 (see
As illustrated in
The earth member 116 is formed by a metallic wire, includes a guide surface 116a inclined upward toward the upstream of the document discharge direction Y with respect to the parallel surface 122a, and is urged toward a protruding position protruding from the parallel surface 122a by the elastic force of the earth member 116 itself. Additionally, the earth member 116 is arranged near the center of the parallel surface 122a in the width direction. Specifically, the earth member 116 is arranged to protrude from the parallel surface 122a between the far end and the close end of the document D when located at the protruding position, in the state where the minimum size document D is located at the center of the width direction. In this manner, the position of the earth member 116 in the width direction is set to the position at which the earth member 116 stably abuts the lower surface of the document D in the state where the document D rests, even when the minimum size document D is discharged.
Additionally, when located at the protruding position, the earth member 116 is arranged to protrude from the parallel surface 122a at the position distant from the upstream end wall 121 in the downstream side. In this manner, the position of the earth member 116 in the document discharge direction Y is set to the position at which the earth member 116 stably abuts the lower surface of the document D in the state where the document D rests, even when the discharged document D does not reach the upstream end wall 121. Further, the earth member 116 is arranged upstream of the middle L1 of the support surface 122 in the document discharge direction Y. Specifically, the earth member 116 is arranged to protrude from the parallel surface 122a in the upstream of the leading edge of the document D in the document discharge direction Y when located at the protruding position, in the state where the minimum size document D is discharged, abuts and rests on the upstream end wall 121. In this manner, the position of the earth member 116 in the document discharge direction Y is set to the position at which the earth member 116 stably abuts the lower surface of the document D in the state where the document D rests, even when the minimum size document D is discharged.
When the document D slides down along the inclined surface 122b (see
Next, referring to
As illustrated in
As described above, in this embodiment, the lower surface of the firstly discharged document located at the bottom among the documents discharged to the discharge space S2 and stacked abuts the earth member 116, irrespective of whether or not the firstly discharged document has reached to the upstream end wall 121. Therefore, even when the discharged document has not reached the upstream end wall 121, the static elimination of the second and subsequent documents is performed by the earth member 116 through the front side of the document discharged first. Accordingly, a stable static elimination effect can be exhibited, and the stacking failure of documents can be reduced.
Additionally, in this embodiment, it is not necessarily required that the discharged document D reaches the upstream end wall 121. Thus, the angle of the inclined surface 122b with respect to the horizontal plane can be made small, and the size of the ADF 2A in the up-and-down direction can be reduced.
Further, in this embodiment, the earth member 116 is formed by metal wires, and is configured to be elastically deformed downward by the own weight of the document D. However, the configuration of the earth member 116 is not limited to this configuration. The earth member 116 may be formed such that at least a portion abutting the document D is formed with an electrically conductive material, and is moved downward by the own weight of the document D. For example, the earth member 116 may be molded with an electrically conductive synthetic resin, and may be supported by the document discharging tray 110 such that the earth member 116 can be rotated to the retracted position as the lower position by the own weight of the document D. Additionally, for example, the earth member 116 may be molded with a synthetic resin that is an insulator, a metal plate or the like may be arranged at the portion abutting the document D, and may be supported by the document discharging tray 110 such that the earth member 116 can be rotated to the retracted position as the lower position by the own weight of the document D. In such a case, the earth member 116 may be urged toward the protruding position by its own weight by arranging the center of gravity on the opposite side of the portion abutting the document D with respect to the rotation center, or may be urged toward the protruding position by a spring, etc.
According to the first embodiment, the stable static elimination effect can be exhibited, and the stacking failure of sheets can be reduced.
Next, a second embodiment in the present invention is described. As for the configurations similar to those in the first embodiment, the illustration will be omitted, or a description will be given by assigning the identical reference numerals to the figures.
As illustrated in
As described above, in this embodiment, even when the documents discharged to the discharge space S2 has not reached the upstream end wall 121, the static elimination of the second and subsequent documents is performed by the earth member 116 through the front side of the firstly discharged document. Thus, the stable static elimination effect can be exhibited, and the stacking failure of documents can be reduced. Additionally, the discharge sensor flag 112 also serves as an earth member. Thus, it is unnecessary to newly provide an earth member in order to perform the static elimination of the discharged document D, and the number of components can be reduced.
Further, the discharge sensor flag 112 may be formed to have a guide surface inclined upward toward the upstream of the document discharge direction Y with respect to the parallel surface 122a. In this case, the discharge sensor flag 112 may be configured such that, when the document D slides down along the inclined surface 122b, the trailing edge of the document D is gently guided upward by the guide surface, and the guide surface is pressed down and moved downward by the own weight of the document D. With such a configuration, the discharge sensor flag 112 can reduce the matching amount by passing the trailing edge of the document D to the upstream of the document discharge direction Y by the guide surface smoothly and without sticking, and can stably abut the lower surface of the document D.
According to the second embodiment, the stable static elimination effect can be exhibited, and the stacking failure of sheets can be reduced.
Next, a third embodiment in the present invention is described. As for the configurations similar to those in the first embodiment, the illustration will be omitted, or a description will be given by assigning the identical reference numerals to the figures.
As illustrated in
Additionally, the earth member 116 is arranged near the center of the parallel surface 122a in the width direction. Specifically, the earth member 116 is arranged at the position at which the earth member 116 abuts the lower surface of the document D in the state where the minimum size document D is located at the center of the width direction. In this manner, the position of the earth member 116 in the width direction is set to the position at which the earth member 116 stably abuts the lower surface of the document D in the state where the document D rests, even when the minimum size document D is discharged. Further, the earth member 116 is arranged at the position at which the downstream end in the document discharge direction Y is distant from the upstream end wall 121 in the downstream side. In this manner, the position of the earth member 116 in the document discharge direction Y is set to the position at which the earth member 116 stably abuts the lower surface of the document D in the state where the document D rests, even when the discharged document D does not reach the upstream end wall 121. Further, the earth member 116 is arranged such that the upstream end in the document discharge direction Y is located upstream of the middle L1 of the support surface 122. Specifically, the earth member 116 is arranged such that the upstream end of the earth member 116 is located upstream of the leading edge of the document D in the document discharge direction Y, in the state where the minimum size document D is discharged, abuts and rests on the upstream end wall 121. In this manner, the position of the earth member 116 in the document discharge direction Y is set to the position at which the earth member 116 stably abuts the lower surface of the document D in the state where the document D rests, even when the minimum size document D is discharged.
As described above, in this embodiment, the earth member 116 is fixed such that the earth member 116 is flush with the parallel surface 122a, or slightly protrude from the parallel surface 122a. In this manner, the earth member 116 can reduce the matching amount by passing the trailing edge of the document D to the upstream of the document discharge direction Y smoothly and without sticking, and it becomes easy to set the abutment area abutting the document D. For example, it becomes easy to set the area of the upper surface 116b of the earth member 116 abutting the document D to be large when the static elimination effect is insufficient, and to set the area of the upper surface 116b to be small when the static elimination effect is excessive. Further, it is desirable that the area of the upper surface 116b is smaller than the area of one surface of the minimum size document. In this manner, it is possible to prevent the static elimination effect from becoming excessive, and to prevent the documents discharged and stacked from being attracted to each other such that it becomes difficult to separate the documents.
Further, in this embodiment, the earth member 116 is arranged at the position at which the earth member 116 abuts the lower surface of the document D in the state where the minimum size document D is located at the center of the width direction. Additionally, the downstream end of the earth member 116 is distant from the upstream end wall 121 in the downstream side of the document discharge direction Y, and the upstream end of the earth member 116 is arranged upstream of the leading edge of the minimum size document D that abuts and rests on the upstream end wall 121. However, the configuration of the earth member 116 is not limited to this configuration. The earth member 116 may be arranged such that the far end is closer to the center than the far end of the document D, and the close end is closer to the center than the close end of the document D in the state where the minimum size document D is located at the center of the width direction. Additionally, the earth member 116 may be arranged such that, for example, the downstream end of the earth member 116 in the document discharge direction Y is upstream of the leading edge of the document D in the document discharge direction Y in the state where the minimum size document D is discharged, abuts and rests on the upstream end wall 121. With such a configuration, even when the minimum size document D is discharged, the entire upper surface 116b of the earth member 116 stably abuts the lower surface of document D in the state where the document D rests. Thus, the stable static elimination effect can be exhibited. In addition, conversely, the earth member 116 may be arranged at the position at which, when a large size document is discharged, the entire upper surface 116b abuts the lower surface of the document, and when a small size document is discharged, a part of the upper surface 116b abuts the lower surface of the document. With such a configuration, the static elimination effect can be adjusted according to the size of the discharged document by changing the area in which the lower surface of the document abuts the upper surface 116b according to the size of the discharged document.
Further, in this embodiment, the earth member 116 is a metal plate formed into the sheet shape along the parallel surface 122a of the support surface 122. However, the configuration of the earth member 116 is not limited to this configuration. The earth member 116 may be formed into a sheet shape with an electrically conductive material. The earth member 116 may be formed into a sheet shape with an electrically conductive synthetic resin, or may be formed into a sheet shape with a metal cloth in which metallic threads are knit. Additionally, the support surface 122 may be formed with a synthetic resin, a portion where the discharged document can abut may be formed with an electrically conductive synthetic resin, the other portion may be formed with a synthetic resin that is an insulator, and these portions may be integrally formed. Additionally, the earth member 116 in the first embodiment may be formed by a sheet shaped metal plate.
According to the third embodiment, the stable static elimination effect can be exhibited, and the stacking failure of sheets can be reduced.
Further, in the first, second and third embodiments described above, the support surface 122 is configured to include the parallel surface 122a that is parallel to the horizontal direction, and the inclined surface 122b that is inclined upward toward the downstream of document discharge direction Y. However, the configuration of the support surface 122 is not limited to this configuration. The support surface 122 may be able to support the lower surface of the discharged document D. For example, each of the parallel surface 122a and the inclined surface 122b may be formed by a flat surface, and the parallel surface 122a and the inclined surface 122b may be connected to each other by a gently curved surface, or each of the parallel surface 122a and the inclined surface 122b may be formed by a curved surface. When each is formed by a curved surface, the angle with respect to the horizontal plane refers to the angle between a virtual surface in which the parallel surface 122a contacts the inclined surface 122b in a predetermined part and the horizontal plane. Additionally, for example, the parallel surface 122a and the inclined surface 122b are not limited to those having a uniform surface in the width direction. For example, a plurality of ribs having a semicircular cross section may be formed in the upper part of the document discharging tray 110 along the document discharge direction Y, such that the upper surfaces of the ribs to which the document D can abut form the parallel surface 122a and the inclined surface 122b. Additionally, for example, the support surface 122 may be configured to include the parallel surface 122a as the second surface that is inclined upward toward to the downstream of document discharge direction Y. Additionally, for example, the support surface 122 may be configured to be inclined upward toward the downstream of the support surface 122 from the upstream end wall 121.
Additionally, in the first, second and third embodiments described above, the document pressing member 115 is configured to be pressed against the document discharging tray 110. However, the configuration of the document pressing member 115 is not limited to this configuration. The document pressing member 115 may extend downward from the lower part of the document tray 4, and abut the discharged document D, such that a frictional force is generated between the document pressing member 115 and the document D. For example, the tip of the document pressing member 115 may be arranged at the position that is distant from the document discharging tray 110 and abuts the discharged document D, or may be configured to be elastically deformed when abutting the document D. Additionally, when the document pressing member 115 is configured to be pressed by the discharged document D so as to be rotated upward, an urging unit urging the document pressing member 115 to be rotated downward may be a spring (not shown), or may be the own weight of the document pressing member 115. Additionally, the document pressing member 115 is configured to be rotatably supported by the document tray 4. However, the configuration of the document pressing member 115 is not limited to this configuration. For example, the document pressing member 115 may be rotatably supported by a frame of the ADF 2A that covers each of the rollers, the conveyance guide 131, etc., or may be rotatably supported by other components forming the ADF 2A.
Additionally, in the first, second and third embodiments described above, the discharge portion discharging a sheet in the discharge direction is configured by the document discharge roller pairs 118. However, the configuration of the discharge portion is not limited to this configuration. The discharge portion may be a part that discharges a sheet to the outside of an apparatus, and maybe, for example, a belt pair, or a combination of a roller and a belt.
Additionally, in the first, second and third embodiments described above, the sheet supporting portion is configured by the document discharging tray 110. However, the configuration of the sheet supporting portion is not limited to this configuration. It is not necessary for the sheet supporting portion to be formed into a sheet shape or a box shape having a bottom. The sheet supporting portion may be formed to be able to stack and support sheets. For example, the sheet supporting portion may be formed into a basket shape that can support a sheet with wire, etc., or may be formed into a rail shape that can partially support a sheet.
Additionally, in the first, second and third embodiments described above, the document discharge apparatus 103 is described that discharges one document D at a time. However, the configuration of the document discharge apparatus 103 is not limited to this configuration. For example, the document discharge apparatus may be configured to discharge a plurality of documents in a bundle.
Additionally, in the first, second and third embodiments described above, the document discharge apparatus 103 as the sheet discharging apparatus that discharges the document D whose image was read by the image reading apparatus 2. However, the configuration of the document discharge apparatus 103 is not limited to this configuration. For example, the sheet discharging apparatus may be formed by a sheet discharge roller pair 25a discharging the sheet P on which an image is formed by the image forming unit 1B, and a sheet discharging tray 23 on which the sheet discharged by the sheet discharge roller pair 25a is stacked.
Additionally, in the first, second and third embodiments described above, the image reading apparatus 2 is described that is provided in the printer 1. However, the configuration of the image reading apparatus 2 is not limited to this configuration. For example, the image reading apparatus 2 may be an apparatus used independently from the printer 1 provided with a printing function.
Additionally, in each of the already-described embodiments, the description is given by using the electrophotography type printer 1. However, the present invention is not limited to this printer 1. For example, the present invention may also be applied to an inkjet type image forming apparatus that forms an image on a sheet by causing a nozzle to discharge a liquid ink.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2017-217797, filed Nov. 10, 2017, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-217797 | Nov 2017 | JP | national |
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| Number | Date | Country |
|---|---|---|
| 10226449 | Aug 1998 | JP |
| 2000-159414 | Jun 2000 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20190144229 A1 | May 2019 | US |
