JP2005035753A - Sheet stacking device and image processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet stacking device capable of exerting a good stacking performance by sensing certainly the uppermost part of sheets ejected to the ejection part and provide an image forming device equipped with such a sheet stacking device. <P>SOLUTION: The sheet stacking device is equipped with a stacking tray 201 for stacking the sheets transported and a first sensing lever 204 and a second sensing lever 206 to abut to the sheets stacked on the stacking tray 201 for sensing them, wherein the levers 204 and 206 work interlockingly to sense the sheets placed on the stacking tray 201. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a sheet stacking unit that constitutes a sheet discharge unit of an image forming apparatus such as a printer, a sheet discharge unit of a sheet post-processing apparatus connected to the image forming apparatus, and an image processing apparatus including the same.

  A discharge tray of the image forming apparatus or the sheet post-processing apparatus includes a stacking tray on which discharged sheets are stacked, and the stacking tray is on the downstream side in the sheet conveyance direction (hereinafter simply referred to as “downstream side”). What is inclined is common.

  This is because after the discharged sheets are stacked on the stacking tray, they slide down on the stacking tray in the direction opposite to the transport direction, and the stack provided on the upstream side of the tray in the sheet transport direction (hereinafter simply referred to as “upstream side”). By causing the rear end of the sheet to abut against the wall, the sheets are neatly aligned in a stacked state, thereby improving the appearance and handling.

  In addition, the sheet stacking unit as described above is provided with a member for detecting the amount of sheets stacked on the stacking tray, and detects that the sheet on the stacking tray has reached a predetermined amount. By stopping the discharge of the sheet, the sheet is prevented from dropping from the stacking tray and from being jammed.

Japanese Patent Laid-Open No. 9-20036

  However, the sheets discharged from the image forming apparatus or the like are not necessarily stacked neatly on the stacking tray by curling or the like, and the uppermost surface of the stacked sheets is not parallel to the stacking tray.

  Also in the conventional apparatus, a member in which a plurality of levers having the same shape or different shapes are connected is arranged so that the sheet can be detected at a plurality of positions in the direction orthogonal to the conveyance direction. However, the uppermost surface of the sheet also in the transport direction, that is, when the upstream side is raised by leaning against the stacking wall on the stacking tray, or when the sheet is raised at a part farther from the downstream stacking wall. Even if it is detected at one point, it may not be the uppermost surface of the entire sheet.

  In particular, in a sorter in which a plurality of bins are arranged in the vertical direction, the area where sheets can be stacked is narrow because the lower surface of the upper stacking tray is the ceiling, but if the uppermost surface of the sheet is not detected reliably, the sheet However, if the sheet is blocked between the trays, the subsequent sheet cannot be discharged, which may lead to deterioration of stackability, jamming, or dropping from the tray.

  In recent years, there has been an increasing demand for more compact equipment. For example, in a sorter, in order to realize equipment with the same level of loading capacity with narrower tray spacing, the above-mentioned problems are caused by narrowing of the tray spacing. It becomes increasingly important.

  Even when a sheet having poor quality such as a large curl is used, it is necessary to more reliably detect the state of the sheet on the stacking tray so that the apparatus can be used without causing a jam.

  The present invention has been made to solve such a problem, and an object of the present invention is to reliably detect the uppermost part of the sheet discharged to the discharge unit and to provide a sheet stacking device having a good stacking property and the same. An image processing apparatus is provided.

  In order to achieve the above object, the first means in the present invention includes a stacking unit for stacking conveyed sheets, and a plurality of sheets for detecting the sheets in contact with the sheets stacked on the stacking unit. And a plurality of sheet detection members that detect the sheets on the stacking unit in conjunction with each other.

  The second means is characterized in that, in the first means, the plurality of sheet detecting members are arranged so as to contact the sheet at different positions in the sheet conveying direction.

  A third means is characterized in that, in the first or second means, the plurality of sheet detection members are arranged so as to be able to contact the sheet at different positions in a direction orthogonal to the sheet conveying direction. To do.

  The fourth means includes detection means for detecting a state of at least one sheet detection member among the plurality of sheet detection members in any one of the first to third means, The detection means detects that the number of sheets stacked on the stacking unit has reached a predetermined amount.

  A fifth means is characterized in that, in the fourth means, a sheet detection member that is not detected by the detection means among the plurality of sheet detection members operates a sheet detection member that is detected by the detection means. .

  The sixth means can detect in any one of the first to fifth means that the sheet has reached a predetermined amount by the plurality of sheet detecting members, and each of the sheet detecting members It is characterized in that the predetermined amount is different.

  The seventh means has connection means for connecting the plurality of sheet detection members in any one of the first to sixth means, and the plurality of sheet detection members are interlocked via the connection means. It is characterized by operating.

  According to an eighth means, in any one of the first to seventh means, at least one of the plurality of sheet detection members also serves as a sheet presence / absence means for detecting the presence / absence of a sheet on the stacking unit. It is characterized by.

  The ninth means includes an image processing means for performing image processing on the sheet in the image processing apparatus that conveys the sheet and performs image processing, and the first to eighth means for discharging and stacking the image processed sheet. And a sheet stacking apparatus according to any one of the means.

  In the first means of the present invention, it is possible to detect the top surfaces of a plurality of sheets in the conveying direction by detecting the position of at least one detection member among the sheet detection members.

  In the second means, the uppermost surface of the sheet can be reliably detected regardless of the state of the sheet stacked on the stacking unit, and deterioration of stacking property, jamming due to a subsequent sheet, and dropping from the stacking unit can be detected. It can be prevented.

  In the third means, the sheet surface can be detected more reliably by detecting the sheet at a plurality of locations in the direction orthogonal to the sheet conveying direction.

  In the fourth means, a sheet detecting member can be reduced to provide a compact and low-cost apparatus.

  In the fifth means, the sheet stacking amount can be reliably detected by one detection means.

  In the sixth means, a larger number of sheets can be stacked as long as there is no problem with sheet stacking.

  In the seventh means, the plurality of sheet detection members can be interlocked in a separated state, and the sheet detection member can be arranged at a more appropriate arbitrary position.

  In the eighth means, not only the amount of sheets stacked on the stacking unit by the sheet detection member but also the presence / absence of sheets can be detected, so that the number of parts can be further reduced.

  In the ninth means, it is possible to efficiently discharge and stack the image-processed sheets.

  Next, exemplary embodiments of the present invention will be described in detail with reference to the drawings.

  However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent.

[First Embodiment]
A sheet stacking apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

{Overall configuration of device}
FIG. 1 is a schematic cross-sectional explanatory diagram of an image forming apparatus. In FIG. 1, an image forming apparatus 100 is connected to a computer or a network such as a LAN, and image information and print signals sent from these computers and networks. Based on the above, an image is formed on the sheet S by a predetermined image forming process, and is discharged to the sheet stacking unit 104.

  In this embodiment, during image formation, the sheet S stacked in the feeding cassette 101 is used as an image processing unit that forms a toner image by a so-called laser beam type image forming process using various rollers. The toner image is transferred to the image forming unit 102, and the toner image is transferred to the upper surface of the sheet in the image forming unit 102. Subsequently, the toner image is permanently fixed by applying heat and pressure in the fixing unit 103 on the downstream side. It has become so.

{Sheet stacking device}
2A and 2B show a portion of the sheet stacking unit 104 of the image forming apparatus 100 as the sheet stacking apparatus according to the present embodiment. FIG. 2A is a side sectional view, and FIG.

  As shown in FIG. 2, a stacking tray 201 as a sheet stacking unit is inclined so that the downstream side is on the upper side, and the sheet S after image formation is discharged onto the stacking tray 201 by a discharge roller pair 202 and discharged. The sheet S thus stacked is stacked on the stacking tray 201 in a state of being abutted against the rear end wall 203.

  A first detection lever 204 and a second detection lever 206 as a sheet detection member for detecting the discharged sheet S are provided in the vicinity of the discharge port to the stacking tray 201. The first detection lever 204 has a rotation shaft 205 on the upstream side of the discharge roller pair 202, and the second detection lever 206 has a rotation shaft 207 on the downstream side of the discharge roller pair 202. Both of them are configured such that the leading ends abut against the upper surface of the sheets stacked on the stacking tray 201.

  The positions at which the respective detection levers abut on the sheets are arranged so as to be different positions in the sheet conveyance direction. In this embodiment, the first detection lever 204 abuts on the upstream side of the sheets discharged to the stacking tray 201. The second detection lever 206 is disposed so as to contact the downstream side of the sheet.

  Further, the first detection lever 204 is positioned below the second detection lever 206, and the rotation side end of the first detection lever 204 is bent upward, as shown in FIG. When the first detection lever 204 rotates, the bent tip pushes up the second detection lever 206. That is, the first detection lever 204 and the second detection lever 206 are configured to operate in conjunction with each other.

  In the present embodiment, a plurality of the first detection levers 204 and the second detection levers 206 are arranged in the sheet width direction (hereinafter simply referred to as “sheet width direction”), which is a direction orthogonal to the sheet conveyance direction. ing.

  The second detection lever 204 has a detected portion 208 as detection means, and the detected portion 208 shields the light transmission type sensor 209 by the rotation of the second detection lever. Motion is detected.

{Sheet detection operation}
Next, an operation at the time of sheet stacking of the sheet stacking unit 104 configured as described above will be described.

  As shown in FIG. 3A, when the sheet S is discharged from the image forming apparatus 100 in the arrow direction A, the leading edge of the sheet first rotates the first detection lever 204 in the arrow B direction.

  Then, as shown in FIG. 3B, the front end of the first detection lever 204 abuts on the second detection lever 206 and the second detection lever 206 also rotates in the direction of arrow C, and the sheet S is then discharged to the discharge roller pair. The first detection lever 204 and the second detection lever 206 are returned to their original positions.

  Then, as shown in FIG. 4A, when a predetermined amount of discharged sheets are stacked on the stacking tray 201, the detected portion 208 of the second detection lever 206 blocks the sensor 209 after the sheets are discharged. Thus, it is detected that the stacking tray 201 is full.

  Here, as shown in FIG. 4A, when the upper surfaces of the sheets stacked on the stacking tray 201 are stacked substantially parallel to the stacking tray 201, the first detection lever 204 and the second detection lever. Both 206 are in contact with the upper surface of the sheet.

  However, the sheet on the stacking tray 201 is not always at a constant height, as shown in FIG. 4 (b), with the central part rising and the trailing edge rising as shown in FIG. 4 (c). It is not.

  In the present embodiment, as shown in FIG. 4B, when the central portion is raised, the second detection lever 206 can detect the stacking height on the downstream side of the sheets.

  Further, as shown in FIG. 4C, when the rear end is raised, the first detection lever 204 contacts and rotates on the upper surface on the upstream side of the sheet. At this time, the front end of the first detection lever 204 is rotated. Comes into contact with the second detection lever 206 and rotates to a position where the detected portion 208 of the second detection lever 206 is detected by the sensor 209.

  Accordingly, the upper surface of the sheet detected by the first detection lever 204 can be detected only by the sensor 209 that detects the position of the second detection lever 206.

{Sheet detection in sorter}
Next, effects when this embodiment is applied to a sorter connected to the image forming apparatus will be described.

  5A and 5B are schematic views in which the sorter 300 is connected to the side surface of the image forming apparatus 100 and the image reading apparatus 400 is connected to the upper side. FIG. 5A is an overall cross-sectional view, and FIG. FIG. Here, as an example, an image forming apparatus having a sorter having three stacking trays and an automatic document feeder 401 having a document discharge tray 402 on the side of the apparatus is shown.

  As shown in FIG. 5A, the sheet set by the flapper 301 in the image forming apparatus 100 so that the discharge direction of the sheet is directed toward the sorter 300 is discharged from another discharge port 302 of the image forming apparatus 100. Thereafter, it is conveyed into the sorter 300. In the sorter 300, the sheet S is further discharged to the stacking tray 304 designated by the flapper 303.

  In the sorter 300 having the above-described configuration, as shown in FIG. 5B, the sheet S is discharged to a region 305 sandwiched between the stacking tray 304a and the stacking tray 304b thereon.

  When the sheets are sequentially stacked and stacked so that the upstream side of the sheets rises, the top surface of the sheet is detected by the first detection lever 204 in the same manner as shown in FIG. On the other hand, when the downstream side of the sheet is raised, the uppermost surface of the sheet is detected by the second detection lever 206 as in the case shown in FIG. At this time, as shown in FIG. 5 (b), even when the height of the stacking portion is regulated, the second detection lever 206 can detect the uppermost surface on the downstream side of the sheet. The distance 306 from the lower surface of the stacking tray 304b can be reliably maintained.

  As a result, the uppermost surface of the sheet hits the lower surface of the upper stacking tray 304b and the interval 306 is eliminated, so that there is no place for the subsequent sheet to be jammed, or an already stacked sheet is pushed out. Can be prevented.

  The first detection lever 204 and the second detection lever 206 have a shape in which a plurality of levers are connected in the sheet width direction, but one wide lever having a sufficient area with respect to the sheet width. You may comprise.

  Further, the first detection lever 204 may be configured to detect the position alone by providing a detected portion and a sensor in the same manner as the second detection lever 206.

[Second Embodiment]
FIG. 6 is a schematic cross-sectional explanatory diagram of a sheet stacking apparatus according to the second embodiment of the present invention. Note that the configuration of the image forming apparatus in which this sheet stacking apparatus is used is the same as that of the first embodiment described above, and members having the same functions as those of the above-described embodiment are denoted by the same reference numerals and redundant description is given. Omitted.

  As shown in FIG. 6 (a), the first detection lever 204 and the second detection lever 206 are connected by a connecting means. In this embodiment, it is comprised so that it may connect by the link means 501 using a link member as a connection means. The first link member 501a and the first detection lever 204 constituting the link means 501 can be integrally rotated about the rotation shaft 205, and the second link member 501b and the second detection lever 206 are rotated about the rotation shaft 207. It can be rotated integrally around the center. The first and second link members 501a and 501b are pivotally attached by the third link member 501c to form a link mechanism so that the first detection lever 204 and the second detection lever 206 rotate in conjunction with each other. It has become.

  Then, as shown in FIG. 6B, when the sheets are stacked and the first detection lever 204 rotates in the direction of arrow D, the second detection lever 206 also rotates in the direction of arrow E via the link means 501. The detected portion 208 of the second detection lever 206 is detected by the sensor 209.

  Accordingly, when the upstream side of the sheet discharged to the stacking tray 201 rises by a predetermined amount, the first detection lever 204 rotates, and when the central portion of the discharged sheet rises by a predetermined amount, 2 Detected by rotation of the detection lever 206.

  In this way, the rotation of one detection lever is transmitted to the other detection lever via the link means 501, and interlocked, so that even if the first detection lever 204 and the second detection lever 206 are separated from each other, The lever can be interlocked, and the detection lever can be arranged at a more appropriate arbitrary position.

[Third Embodiment]
FIG. 7 is a schematic cross-sectional explanatory view of a sheet stacking apparatus according to the third embodiment of the present invention. The configuration of the image forming apparatus in which this sheet stacking apparatus is used is the same as that of the first embodiment described above, and members having the same functions as those of the above-described embodiment are denoted by the same reference numerals and redundant description is given. Omitted.

  In the present embodiment, as shown in FIG. 7A, for example, a recess is formed on the sheet stacking surface of the stacking tray 201, and the tip of the second detection lever 206 is inserted into the recess. When the sheet does not exist on the stacking tray 201, the tip of the second detection lever 206 is positioned below the stacking surface of the stacking tray 201. At this time, the detected portion 208 is not at the position of the sensor 209.

  Then, as shown in FIG. 7B, when the sheets S are stacked on the stacking tray 201, the second detection lever 206 is rotated, the detected portion 208 is detected by the sensor 209, and the sheets are placed on the stacking tray 201. Is detected.

  After the sheets are sequentially stacked, as shown in FIG. 7C, when the detected part 208 comes to a position where it is not detected by the sensor 209, it is detected that the predetermined amount has been reached.

  In the configuration of the present embodiment, the second detection lever 206 also serves as a sheet presence / absence detection unit. In addition to whether or not the second detection lever 206 has reached a predetermined amount of sheets, It becomes possible to detect the presence or absence of the sheet.

  Two sensors 209 are provided in parallel, and the first sensor detects when one sheet is stacked, and the second sensor or both sensors detect when a predetermined amount of sheets are stacked. Anyway.

[Fourth Embodiment]
FIG. 8 is a schematic cross-sectional explanatory view of a sheet stacking apparatus according to the fourth embodiment of the present invention. The configuration of the image forming apparatus in which this sheet stacking apparatus is used is the same as that of the first embodiment described above, and members having the same functions as those of the above-described embodiment are denoted by the same reference numerals and redundant description is given. Omitted.

  As shown in FIG. 8, the first detection lever 204 that detects the upstream sheet surface of the sheet discharged to the stacking tray 201 and the second detection lever 206 that detects the downstream sheet surface detect the uppermost surface of the sheet. The distances F (upstream distance) and G (downstream distance) between the tip of the detection lever and the stacking tray surface when detecting that the sheet has reached a predetermined amount are different.

  Then, as shown in FIG. 8, by configuring so that F <G, when the downstream side of the discharged sheets is stacked so that it rises, the number of sheets is increased as long as there is no problem in discharging the sheets. Sheets can be stacked.

[Fifth Embodiment]
FIG. 9 is a schematic cross-sectional explanatory view of a sheet stacking apparatus according to the fifth embodiment of the present invention. The configuration of the image forming apparatus in which this sheet stacking apparatus is used is the same as that of the first embodiment described above, and members having the same functions as those of the above-described embodiment are denoted by the same reference numerals and redundant description is given. Omitted.

  In the present embodiment, as shown in FIG. 9A, a sheet presence / absence detection lever 307 that rotates in the direction of arrow H about the shaft 307a by the weight of the sheet from the lower surface of the stacking tray 304 of the sorter 300 is provided. Have. The sheet presence / absence detection lever 307 is configured to be interlocked with the second detection lever 206 via a link lever 308 that is rotatable about a shaft 308a.

  In the present embodiment, as shown in FIG. 9B, in the state where the sheet S is present on the stacking tray 304, the second detection lever 206 is moved to the arrow J in conjunction with the rotation of the sheet presence / absence detection lever 307. The detected portion 208 is at a position detected by the sensor 209 at this time. As a result, it is possible to detect whether or not there is a sheet on the stacking tray 304.

  Thereafter, when the sheets are sequentially stacked, the first detection lever 204 and the second detection lever 206 are pushed up and rotated on the sheet surface, and the detected portion 208 comes to a position where it is not detected by the sensor 209. It is detected that it has been reached.

  This embodiment can detect the presence / absence of sheets on the stacking tray as in the third embodiment described above, and even if sheets are inserted into the stacking tray 304 from the opposite side to the conveying direction as compared with the third embodiment. Can be guided to the lower side of the detection lever.

  Even in the present embodiment, two sensors 209 are provided in parallel, the first sensor when a single sheet is stacked, and the second sensor or the second sensor when a predetermined amount of sheets are stacked. It may be configured to be detected by both sensors.

[Other Embodiments]
In the above-described embodiment, an example in which the sheet stacking apparatus is used in the image forming apparatus has been described. However, even in the case of an image reading apparatus such as a scanner including an image reading unit that reads a document or the like as an image processing unit, the above-described sheet stacking apparatus is used. By using this, it is possible to reliably detect the uppermost surface of the sheet when discharging and stacking a sheet document, and it is possible to prevent deterioration of stackability, jamming due to subsequent sheets, and dropping from the stacking unit.

  In the above-described embodiment, the light transmission type sensor is used as the detection means for detecting the position of the detection lever. However, this is not limited to the optical sensor, and may be other detection means such as a touch sensor. It is natural.

1 is a schematic cross-sectional explanatory diagram of an image forming apparatus. 1A and 1B show a portion of a sheet stacking portion of an image forming apparatus as a sheet stacking apparatus according to a first embodiment, in which FIG. It is operation | movement explanatory drawing of a 1st detection lever and a 2nd detection lever. FIG. 10 is an explanatory diagram illustrating a state in which a detection lever operates according to a state of sheets discharged to a stacking tray. FIG. 2 is a schematic diagram in which a sorter is connected to a side surface of the image forming apparatus, and an image reading device is connected to the upper part. FIG. FIG. 5 is a schematic cross-sectional explanatory diagram of a sheet stacking apparatus according to a second embodiment of the present invention. FIG. 10 is a schematic cross-sectional explanatory diagram of a sheet stacking apparatus according to a third embodiment of the invention. FIG. 10 is a schematic cross-sectional explanatory diagram of a sheet stacking apparatus according to a fourth embodiment of the invention. FIG. 10 is a schematic cross-sectional explanatory diagram of a sheet stacking apparatus according to a fifth embodiment of the invention.

Explanation of symbols

S ... Sheet
100 ... Image forming apparatus
101 ... Feed cassette
102 ... Image forming section
103 Fixing unit
104 ... Sheet stacking section
201… Loading tray
202… discharge roller pair
203… rear end wall
204… First detection lever
205… Rotating axis
206… Second detection lever
207… Rotating shaft
208… detected part
209… Sensor
300… Sorter
301… Flapper
302… discharge port
303 Flapper
304, 304a, 304b ... Loading tray
305… Area
306… Interval
307… Seat presence / absence detection lever
307a ... axis
308… Link lever
308a ... axis
400 ... Image reading device
401 ... Automatic document feeder
402… Document output tray
501 ... Link means
501a, 501b, 501c ... Link member

Claims (9)

A stacking unit for stacking the conveyed sheets;
A plurality of sheet detection members for detecting the sheets in contact with the sheets stacked on the stacking unit;
Have
The sheet stacking apparatus configured to detect the sheets on the stacking unit in conjunction with each other. The sheet stacking apparatus according to claim 1, wherein the plurality of sheet detection members are disposed so as to be in contact with the sheets at different positions in a sheet conveyance direction. 3. The sheet stacking apparatus according to claim 1, wherein the plurality of sheet detection members are arranged to be able to contact the sheet at different positions in a direction orthogonal to the sheet conveyance direction. A detecting means for detecting a state of at least one sheet detecting member among the plurality of sheet detecting members;
4. The sheet stacking apparatus according to claim 1, wherein the detection unit detects that the number of sheets stacked on the stacking unit has reached a predetermined amount. 5. 5. The sheet stacking apparatus according to claim 4, wherein, among the plurality of sheet detection members, a sheet detection member that is not detected by the detection unit operates a sheet detection member that is detected by the detection unit. 6. The apparatus according to claim 1, wherein the plurality of sheet detecting members can detect that the sheet has reached a predetermined amount, and the predetermined amount is different for each sheet detecting member. A sheet stacking device according to claim 1. 7. The apparatus according to claim 1, further comprising a coupling unit that couples the plurality of sheet detection members, wherein the plurality of sheet detection members operate in conjunction with each other via the coupling unit. Sheet stacking device. 8. The sheet stacking apparatus according to claim 1, wherein at least one of the plurality of sheet detecting members also serves as a sheet presence / absence unit that detects the presence / absence of a sheet on the stacking unit. In an image processing apparatus that conveys a sheet and processes an image,
Image processing means for performing image processing on the sheet;
The sheet stacking apparatus according to any one of claims 1 to 8, for discharging and stacking image-processed sheets;
An image processing apparatus comprising:

Images