JP2011042434A - Sheet carrying device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet carrying device and an image forming device further surely controlling sheet carrying operation, by providing a wide detectable range, without enlarging a position detecting means. <P>SOLUTION: This sheet carrying device 1 has a control means for controlling so that a position of the uppermost sheet becomes a reference position, by storing the position as the reference position by being detected by an upstream side uppermost sheet detecting means 16, by adjusting the position of the uppermost sheet 2A detected by a downstream side uppermost sheet detecting means 15 up to a position sucked by a sheet sucking carrying means 12, wherein the upstream side uppermost sheet detecting means has upper surface position detecting members 16B-D for rotatably supporting one end and placing the other end on the uppermost sheet and an angle detecting means 16A for detecting a rotation angle of the upper surface position detecting member, and stores position information on the uppermost sheet in a control means as angle information detected by an angle detecting means. The image forming device has this sheet carrying device. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a digital multi-function machine that combines these functions, and a sheet conveying apparatus used for these.

As a transport device for feeding a recording medium such as paper (hereinafter referred to as “sheet”) in an image forming apparatus such as a copying machine, a printer, a facsimile, and a digital multifunction machine that combines these functions, for example, An air suction type sheet conveying apparatus is known.
An example of an air suction type sheet conveying apparatus is shown in FIGS.

  As shown in FIG. 6, the sheet conveying apparatus is provided with a sheet adsorbing / conveying means 112 having a sheet conveying belt 112C above the sheet storage unit 111, and a plurality of sheets stacked on the stacking tray 111A ( Hereinafter, the uppermost sheet (hereinafter referred to as the “uppermost sheet”) 102A in the vertical direction of the sheet bundle 102 (hereinafter also referred to as “sheet bundle”) 102A is attracted to the sheet conveying belt 112C one by one by the air suction unit 113 and predetermined. It is comprised so that it may convey to.

  As shown in FIG. 7, a blowing unit 114 is provided on the downstream side (right side in the drawing) in the sheet conveyance direction, and air is blown to one end of the sheet bundle 102, so that the sheet near the uppermost sheet 102 </ b> A is 1 Separate one by one. On the other hand, a position detection sensor 116 is provided at an upstream end that is not affected by the air blown from the blower 114. The position detection sensor 116 includes a position detection unit (for example, a digital sensor) 116A and an upper surface position detection lever 116B.

The stacking tray 111A is connected to the sheet lifting / lowering driving means 118 and can move up and down.
The sheet bundle 102 ascends together with the stacking tray 111A, the uppermost sheet 102A comes into contact with the upper surface position detection lever 116B, and the position of the uppermost sheet 102A is detected by receiving the force by which the upper surface position detection lever 116B is pushed up. It is configured.

  A large number of suction holes (not shown) are formed on the entire surface of the sheet conveying belt 112C. By the air suction from the suction unit 113, the uppermost sheet 102A is adsorbed to the sheet conveying belt 112C through the suction hole.

A sheet conveying operation will be described with reference to FIG.
First, the sheet raising / lowering driving unit 118 raises the stacking tray 111A, and determines whether or not the position detection sensor 116 detects the upstream end of the sheet bundle 102 in the conveyance direction of the uppermost sheet 102A. When it is not detected, that is, when the uppermost sheet 102A is not in contact with the upper surface position detection lever 116B, the sheet raising / lowering driving means 118 further raises the stacking tray, and the uppermost sheet 102A is in contact with the upper surface position detection lever 116B. The sheet raising / lowering driving means 118 stops the stacking tray.

Next, air is blown to the sheet bundle 102 by the blower unit 114, and adjacent sheets including the uppermost sheet 102A are separated one by one. The lifted uppermost sheet 102A is attracted to the sheet conveying belt 112C by air suction from the suction unit 113, and the sheet conveying belt 112C is rotated by the driving device 117, whereby the sucked uppermost sheet 102A is moved to a predetermined position. Transport.
Thus, the uppermost sheet 102A is sequentially conveyed, the number of sheets in the sheet bundle 102 decreases, and the vertical position of the uppermost sheet 102A decreases. While the uppermost sheet 102A is detected by the position detection sensor 116, the sheet conveyance operation is continued. When the uppermost sheet 102A is not detected, the sheet raising / lowering driving unit 118 is operated to raise the stacking tray 111A.

In the above-described sheet conveying apparatus, it is important that the uppermost sheet is in a position suitable for being attracted to the sheet conveying belt, and it is important to detect the exact position of the uppermost sheet.
Therefore, as shown in FIG. 8, the reference position detection sensor 115 is provided on the downstream side in the sheet conveying direction, and the uppermost sheet 102A raised by the sheet lifting / lowering driving means 118 has reached the position where it is attracted to the sheet conveying belt 112C. Has been proposed, and this position is stored in the analog position detection sensor 116 on the upstream side of the seat (see, for example, Patent Document 1).
According to the method described in Patent Document 1, during the sheet conveyance operation, control is performed based on the position (height) of the upstream end portion, not the downstream region in which the uppermost sheet is attracted or floated by air blowing. In other words, it is possible to prevent double feeding and non-feeding of sheets.

  In addition, a method has been proposed in which a pressing unit is provided at an upstream position in the sheet feeding direction so that the sheet can be stably fed when the sheet is lifted by blowing (see, for example, Patent Document 2).

The upper surface of the sheet bundle placed on the stacking tray is not always horizontal, and may have curl wrinkles due to various factors, and the height may be different between the upstream side and the downstream side in the sheet conveying direction.
For example, as shown in FIGS. 8 and 9, when the end portion height of the uppermost sheet 102 </ b> A is different, the position detection sensor 116 uses a curl wrinkle with respect to the reference position detected by the reference position detection sensor 115. Since it is necessary to detect the uppermost sheet within a range including the increasing / decreasing height, the detection range of the position detection sensor 116 is required to be wide.

  However, in the apparatus described in Patent Document 1, since the position detection sensor at the upstream end detects the position by moving up and down, in order to widen the detection range, the detection unit 116C is lengthened. This leads to an increase in size of the position detection sensor 116. Similarly, the apparatus described in Patent Document 2 has a problem that the detection means is increased in size, and further, the transfer apparatus itself is increased in size and cost.

  An object of the present invention has been made in view of the above problems in the prior art, and a wide detectable range can be obtained without increasing the size of a means for detecting the position of the uppermost sheet of a sheet bundle, and the sheet. It is an object of the present invention to provide a sheet conveying apparatus capable of more reliably controlling the conveying operation and an image forming apparatus including the sheet conveying apparatus.

In order to solve the above problems, a sheet conveying apparatus according to the present invention is as follows.
[1] A sheet storage unit for stacking and storing sheet bundles on a stacking tray;
Sheet raising / lowering drive means for raising and lowering the stacking tray in the vertical direction;
Sheet adsorbing and conveying means for adsorbing and conveying the uppermost sheet of the sheet bundle;
For the sheet bundle, a blower that blows air from the downstream side in the sheet conveying direction and floats the upper part sheet including at least the uppermost sheet to separate the sheets,
A downstream-side uppermost sheet detecting means that is disposed downstream of the sheet conveying direction and detects the position of the uppermost sheet by a non-contact means;
An upstream uppermost sheet detection means that is disposed upstream of the sheet conveying direction and detects the position of the uppermost sheet by the contact means;
The position of the uppermost sheet detected by the downstream uppermost sheet detecting means is adjusted by the sheet raising / lowering driving means to a position attracted by the sheet suction / conveying means, and the position is adjusted by the upstream uppermost sheet detecting means. And a control unit that controls the position of the uppermost sheet detected by the upstream uppermost sheet detection unit during the sheet conveyance to be the reference position.
The upstream uppermost sheet detecting means includes an upper surface position detecting member having one end rotatably supported and the other end placed on the uppermost sheet, and an angle detecting means for detecting a rotation angle of the upper surface position detecting member. And the control means stores the position information of the uppermost sheet as angle information detected by the angle detection means.
[2] An upstream end regulating member that regulates an upstream end of the sheet bundle stored in the sheet storage unit in the sheet conveyance direction,
The sheet conveying apparatus according to [1], wherein the upstream uppermost sheet detecting means is provided integrally with the upstream end regulating member.
[3] The above-mentioned [1], wherein an end portion of the upper surface detection member placed on the uppermost sheet is provided with a roller that comes into contact with the uppermost sheet and is driven as the uppermost sheet moves. ] To [2].
[4] An image forming apparatus comprising the sheet conveying device according to any one of [1] to [3].
[5] The image forming apparatus according to [4], which is any one of an electrophotographic copying machine, a printer, a facsimile machine, and an offset printing machine.

  According to the present invention, a sheet conveying apparatus capable of obtaining a wide detectable range and controlling the sheet conveying operation more reliably without increasing the size of the means for detecting the position of the uppermost sheet of the sheet bundle, and An image forming apparatus including a sheet conveying device can be provided.

According to the first aspect of the present invention, a sheet storage unit that stacks and stores the sheet bundle on the stacking tray, a sheet lifting / lowering drive unit that lifts and lowers the stacking tray in the vertical direction, and an uppermost sheet of the sheet bundle are sucked. A sheet adsorbing and conveying unit that conveys the sheet bundle, an air blowing unit that blows air from the downstream side in the sheet conveying direction with respect to the sheet bundle, and floats an upper sheet including at least the uppermost sheet to separate the sheets, and sheet conveyance Arranged on the downstream side in the direction and detects the position of the uppermost sheet by the non-contact means, and arranged on the upstream side in the sheet conveying direction and detects the position of the uppermost sheet by the contact means. The position of the uppermost sheet detected by the upstream uppermost sheet detecting means and the lowermost uppermost sheet detecting means is set to the position where the uppermost sheet is detected by the sheet adsorbing and conveying means. The position of the uppermost sheet detected by the upstream uppermost sheet detecting means during sheet conveyance is adjusted by the sheet raising / lowering driving means, detected by the upstream uppermost sheet detecting means and stored as a reference position. The upstream uppermost sheet detecting means is an upper surface position at which one end is rotatably supported and the other end is placed on the uppermost sheet. A sheet conveying unit that includes a detection member and an angle detection unit that detects a rotation angle of the upper surface position detection member, and stores the position information of the uppermost sheet in the control unit as angle information detected by the angle detection unit; Since this is an apparatus, the position detection range of the uppermost sheet in the sheet bundle can be widened without increasing the size of the detection means, and the sheet conveying operation can be performed reliably. It is possible.
According to a second aspect of the present invention, in the sheet conveying apparatus according to the first aspect, an upstream side end regulating member that regulates an upstream end in the sheet conveying direction of the sheet bundle stored in the sheet storing unit. And the upstream uppermost sheet detecting means is provided integrally with the upstream end regulating member, so that the size of the apparatus is not increased.
According to the invention of claim 3, in the sheet conveying apparatus according to any one of claims 1 to 2, an end portion of the upper surface detection member placed on the uppermost sheet abuts on the uppermost sheet, Since the roller that is driven in accordance with the movement of the uppermost sheet is provided, it is possible to perform the sheet conveyance operation more reliably without causing a problem in the sheet conveyance operation due to the influence of the upper surface detection member.
According to the fourth aspect of the present invention, since the image forming apparatus includes the sheet conveying apparatus according to any one of the first to third aspects, the sheet conveying operation can be reliably controlled without increasing the size of the apparatus. Can do.
According to the invention of claim 5, the electrophotographic copying machine, the printer, the facsimile, and the offset printing machine can be set as apparatuses capable of reliably controlling the sheet conveying operation without increasing the size of the apparatus.

It is a schematic sectional drawing which shows one embodiment of the sheet conveying apparatus of this invention. It is a schematic sectional drawing explaining an example of the sheet conveyance operation | movement of the sheet conveying apparatus of this invention. It is a schematic sectional drawing from the arrow Z direction shown in FIG. 2 of the sheet conveying apparatus of this invention. FIG. 5 is a schematic cross-sectional view showing an example of a mode in which sheet bundles having curl ridges are stacked in the sheet conveying apparatus of the present invention. FIG. 6 is a schematic cross-sectional view showing another example of a mode in which sheet bundles having curl hooks are stacked in the sheet conveying apparatus of the present invention. It is a schematic sectional drawing which shows an example of the conventional sheet conveying apparatus. It is a figure explaining operation | movement of the sheet conveying apparatus of FIG. FIG. 10 is a cross-sectional view illustrating an example in which a reference position detection sensor is provided on the downstream side in the sheet conveying direction as another example of a conventional sheet conveying apparatus. FIG. 9 is a schematic cross-sectional view illustrating an example of a state in which a curled ridge is attached to an end portion of the stacked sheet bundle in the sheet conveying apparatus of FIG. 8. FIG. 9 is a schematic cross-sectional view illustrating another example of a state in which a curled ridge is attached to an end portion of the stacked sheet bundle in the sheet conveying apparatus of FIG. 8.

  Hereinafter, a sheet conveying apparatus according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and other embodiments, additions, modifications, deletions, and the like can be changed within a range that can be conceived by those skilled in the art, and any aspect is possible. As long as the functions and effects of the present invention are exhibited, the scope of the present invention is included.

  FIG. 1 is a cross-sectional view illustrating a configuration of a sheet conveying apparatus according to the present invention, FIG. 2 is a diagram illustrating a state in which the uppermost sheet is adsorbed to a sheet conveying belt, and FIG. FIG.

  As shown in FIG. 1, the sheet conveying apparatus 1 includes a sheet storage unit 11, a sheet suction conveyance unit 12, a suction unit (air suction unit) 13, a blower unit (air blower unit) 14, and a drive unit 17. , A sheet raising / lowering drive means 18, a downstream uppermost sheet detecting means 15, an upstream uppermost sheet detecting means 16, and a control means (not shown).

The sheet storage unit 11 can stack a sheet bundle 2 composed of a plurality of sheets stacked on a stacking tray 11A that is a horizontal plane.
The stacking tray 11A of the sheet storage unit 11 is connected to a sheet lifting / lowering drive unit 18 connected to the control unit. When the sheet lifting / lowering driving unit 18 is driven, the stacking tray 11A moves up and down, and the inside of the sheet storage unit 11 is moved. The sheet bundle 2 moves up and down.

  The sheet adsorbing and conveying means 12 includes a driving unit 17 connected to the control means, rollers 12A and 12B, and a sheet conveying belt 12C that spans the rollers 12A and 12B. The sheet conveying belt 12C includes a sheet conveying belt 12C as shown in FIG. A large number of suction holes 12D are formed throughout. A suction unit 13 for sucking air from the suction hole 12D is provided in an internal space surrounded by the endless sheet conveying belt 12C. The sheet sucked by air from the suction unit is adsorbed to the sheet conveyance belt 12 </ b> C that is an adsorption unit.

  The suction unit 13 is connected to control means, and suction is controlled by the control means. By performing air suction from the suction unit, the topmost sheet 2A at the top in the vertical direction among the plurality of sheet bundles 2 stacked on the stacking tray 11A as shown in FIG. Adsorbed to the sheet conveying belt 12C. As the roller rotates by the driving unit 17, the sheet conveying belt 12C rotates while adsorbing the uppermost sheet 2A, and conveys the uppermost sheet 2A to a desired position. The drive unit 17 is controlled by the control unit.

  Here, for convenience of explanation, four side surfaces (side end portions) of the sheet bundle are represented as 2B, 2C, 2D, and 2E. As shown in FIG. 2, each side surface includes a downstream side surface (right end portion in the drawing) 2B in the sheet conveyance direction and an upstream side surface (left end portion in the drawing) 2C in the sheet conveyance direction. As shown in FIG. 3, the left end 2D and the right end 2E of the figure face each other.

  The air blower 14 is disposed on the 2B side of the sheet bundle 2 as shown in FIG. In addition, the ventilation part 14 is connected to the control means. By blowing air from the blower unit 14 to the upper part on the 2B side of the sheet bundle 2, the upper sheet including at least the uppermost sheet 2A can be levitated and the sheets can be separated. In addition, in this embodiment, although the ventilation part 14 was arrange | positioned so that it might ventilate to 2B surface, you may arrange | position in the position which ventilates to 2D and 2E.

The downstream uppermost sheet detection means 15 is a means for detecting the position of the uppermost sheet 2A by a non-contact method, and is, for example, a non-contact type digital sensor such as a reflective optical photosensor. The downstream uppermost sheet detection means 15 is connected to the control means.
In the example of FIG. 1, the downstream uppermost sheet detection means 15 is provided above the 2B side in the vertical direction in order to detect the 2B side end of the uppermost sheet 2A.

  The sheet bundle 2 is lifted together with the stacking tray 11A by the sheet lifting / lowering driving means 18 until reaching the position in the vertical direction that is optimal for the uppermost sheet 2A being sucked by the suction unit 13. When the downstream uppermost sheet detecting means 15 detects that the uppermost sheet 2A has reached the position, the sheet raising / lowering driving means 18 stops.

  The upstream uppermost sheet detecting means 16 is a means for detecting the position of the uppermost sheet 2A by contact. For example, one end of the uppermost sheet detecting means 16 is rotatably supported and the other end is placed on the uppermost sheet 2A. The upper surface position detecting member comprising the uppermost sheet contact portion 16D and the arm 16B, and the angle detecting means 16A for detecting the rotation angle around the fulcrum 16C of the arm 16B of the upper surface position detecting member. The angle detection unit 16A is, for example, an analog voltage output angle detection sensor. The upstream uppermost sheet detection means 16 is connected to the control means.

The upper surface position detection member is configured such that the arm 16B rotates with the fulcrum 16C as a fulcrum, and the uppermost sheet contact portion 16D that is always in contact with the uppermost sheet 2A can move vertically in the vertical direction by the rotational movement of the arm. It is configured. The rotation angle of the arm accompanying the vertical movement of the uppermost sheet contact portion 16D is detected by the angle detection means 16A.
In the sheet conveying apparatus of the present invention, the position information of the uppermost sheet 2A is stored in the control means as the angle information detected by the angle detection means 16A.

As described above, when the uppermost sheet detection means 15 on the downstream side detects that the uppermost sheet 2A has reached the position, the sheet raising / lowering driving means 18 stops. Next, the position is detected by the upstream uppermost sheet detecting means 16 and stored as reference position data indicating that the uppermost sheet 2A is at the reference position.
Even if the sheet conveyance belt 12C adsorbs the downstream end portion (2B side in FIG. 2) of the uppermost sheet 2A by the adsorbing unit 13, the uppermost sheet contact portion 16D is upstream of the uppermost sheet 2A. Since the end portion (2C side in FIG. 2) is pressed to suppress levitation, the upstream uppermost sheet detection means 16 recognizes the position of the upstream end portion (2C side in FIG. 2) that is not attracted. Accordingly, stable sheet suction conveyance can be performed based on the reference position data stored by the control means.

  As shown in FIG. 2, the uppermost sheet contact portion 16D in contact with the 2C side of the uppermost sheet 2A of the upstream uppermost sheet detection means 16 is driven and rotated as the sheet of the uppermost sheet 2A moves. Therefore, a series of operations in which the uppermost sheet 2A is adsorbed and conveyed by the sheet conveying belt 12C is not hindered by the upstream uppermost sheet detecting unit 16.

  The sheet conveying device includes an upstream end regulating member (end fence) that regulates an upstream end in the sheet conveying direction of the sheet bundle in the sheet storage unit. As shown in FIGS. 1 and 2, the upstream uppermost sheet detecting means 16 is preferably provided integrally with the upstream end regulating member 22. With such a configuration, the sheet conveying apparatus is not increased in size.

4 and 5, the end of the sheet bundle 2 has a curl hook, and the uppermost sheet detected on the upstream side (2C side in the figure) and the downstream side (2B side in the figure) in the sheet conveying direction. It is a figure which shows the case where a position differs.
4 shows a state in which the position of the uppermost sheet is 6 mm higher (+6 mm) on the 2C side than the 2B side, and FIG. 5 shows a state in which the position of the uppermost sheet is 6 mm lower on the 2C side than the 2B side (−6 mm). Is shown. In this case, with respect to the position detected by the downstream uppermost sheet detection means 15, the upstream uppermost sheet detection means 16 requires an expanded detection range of at least 6 mm in the vertical direction and a total of 12 mm.
In the sheet conveying apparatus of the present invention, the angle detection means 16A detects the rotation angle around the fulcrum 16C of the arm 16B as the uppermost sheet contact portion 16D moves up and down, and the detected rotation angle information is the highest position. It becomes the position information of the sheet. For this reason, position detection by vertical movement of the sensor in the conventional sheet conveying apparatus is unnecessary, the space required by the detecting means can be reduced, and a wide detection range is ensured without increasing the size of the sheet conveying apparatus itself. can do.

  In addition to the analog voltage output type, the angle detection unit 16A may be, for example, a method of detecting an angle by digital output having a detection pattern at the fulcrum 16C.

The image forming apparatus of the present invention includes the sheet conveying apparatus of the present invention. Specifically, the image forming apparatus includes an image forming unit in the apparatus main body, and further includes a conveying path including the sheet conveying apparatus of the present invention. An image is formed in the image forming unit by including a sheet storage unit that stores printing paper, and the printing paper disposed on the stacking tray of the sheet storage unit being transported through a transport path including the sheet transport device of the present invention. The The sheet on which the image is formed is discharged to a paper discharge tray or the like.
By using the sheet conveying apparatus of the present invention for an image forming apparatus, the image forming apparatus can be made compact and the sheet conveying operation can be more reliably controlled.

  Examples of the image forming apparatus of the present invention include an electrophotographic copying machine, a printer, a facsimile machine, and an offset printing machine.

DESCRIPTION OF SYMBOLS 1 Sheet conveying apparatus 2 Sheet bundle 2A Uppermost sheet 11 Sheet storage part 11A Stacking tray 12 Sheet adsorption | suction conveyance means 12A Roller 12B Roller 12C Sheet conveyance belt 12D Suction hole 13 Suction part 14 Air blower 15 Downstream uppermost sheet detection means 16 Upstream Side uppermost sheet detection means 16A Angle detection means (angle detection sensor)
16B arm 16C fulcrum 16D uppermost sheet contact portion 17 drive portion (sheet suction conveyance means drive portion)
18 Seat elevating drive means 22 Upstream end regulating member (end fence)

JP 2007-45630 A JP 2001-206573 A

Claims (5)

A sheet storage unit for stacking and storing sheet bundles on a stacking tray;
Sheet raising / lowering drive means for raising and lowering the stacking tray in the vertical direction;
Sheet adsorbing and conveying means for adsorbing and conveying the uppermost sheet of the sheet bundle;
For the sheet bundle, a blower that blows air from the downstream side in the sheet conveying direction and floats the upper part sheet including at least the uppermost sheet to separate the sheets,
A downstream-side uppermost sheet detecting means that is disposed downstream of the sheet conveying direction and detects the position of the uppermost sheet by a non-contact means;
An upstream uppermost sheet detection means that is disposed upstream of the sheet conveying direction and detects the position of the uppermost sheet by the contact means;
The position of the uppermost sheet detected by the downstream uppermost sheet detecting means is adjusted by the sheet raising / lowering driving means to a position attracted by the sheet suction / conveying means, and the position is adjusted by the upstream uppermost sheet detecting means. And a control unit that controls the position of the uppermost sheet detected by the upstream uppermost sheet detection unit during the sheet conveyance to be the reference position.
The upstream uppermost sheet detecting means includes an upper surface position detecting member having one end rotatably supported and the other end placed on the uppermost sheet, and an angle detecting means for detecting a rotation angle of the upper surface position detecting member. And the control means stores position information of the uppermost sheet as angle information detected by the angle detection means. An upstream end regulating member that regulates an upstream end of the sheet bundle stored in the sheet storing unit in the sheet conveying direction;
The sheet conveying apparatus according to claim 1, wherein the upstream uppermost sheet detecting unit is provided integrally with the upstream end regulating member.   The end of the upper surface detection member placed on the uppermost sheet is provided with a roller that abuts on the uppermost sheet and follows as the uppermost sheet moves. The sheet conveying apparatus according to any one of the above.   An image forming apparatus comprising the sheet conveying device according to claim 1.   The image forming apparatus according to claim 4, wherein the image forming apparatus is one of an electrophotographic copying machine, a printer, a facsimile machine, and an offset printing machine.

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