JP2004284827A - Sheet feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply sheets to a first sheet containing component assuredly. <P>SOLUTION: This sheet feeder transfers sheets S in a second sheet containing component 5 collectively to a first sheet containing component 4 by a transfer driving component 13 when the sheets S contained in the component 4 run out. An opening 35 for sheet detection is formed on a bottom plate 6 of the component 4 and a reflection optical sensor 36 is placed facing to the opening 35, to detect presence of the sheets S on the bottom plate 6 of the component 4. Accordingly, as long as there is a piece of sheet S on the bottom plate 6 of the component 4, the optical sensor 36 can detect the presence of the sheets S on the bottom plate 6 regardless of a curving tendency of the sheets S, which enables solving a problem that the sheets S on the component 5 are supplied even if the sheets S on the component 4 are left and also allows the sheets S on the component 5 to be supplied assuredly to the component 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a paper feeding device that feeds paper to a printing device, a copying machine, and the like.

  For example, a commercial copying machine or the like consumes a large amount of paper, so that some models have a large-capacity paper feeding device. As such a paper feeding device, there is a paper feeding device in which a first paper storage portion and a second paper storage portion are arranged along a paper feeding direction, and is described in, for example, Patent Document 1 or the like.

  Such a paper feeding device is called a tandem tray system or the like, and usually separates and feeds the paper stored in the first paper storage unit one by one by the paper supply unit. The presence or absence of paper in the first paper storage unit is constantly monitored by a detector, and when a state in which paper is exhausted is detected, the bottom plate of the first paper storage unit is lowered to the lowest position, and the transfer drive unit As a result, a bundle of sheets is fed from the second sheet storage unit to the first sheet storage unit at a time in a sliding state and replenished. For this reason, the above-described paper feeding device can continuously feed a very large amount of paper, and can reduce the frequency of the user's work of replenishing the paper.

JP-A-06-340342

  In the above-described paper feeder, a paper detector having an actuator that is displaced by a load of the paper on a bottom plate on which the paper is loaded is used to detect the presence or absence of the paper in the first paper storage unit. . However, when the number of sheets on the bottom plate is small, the actuator may not operate sensitively depending on the sheet setting state. In particular, when the surface of a sheet is curved so as to bulge upward, the smaller the number of sheets stacked thereon, the more the sheet floats from the actuator. In such a state, it is determined that the paper has run out despite the paper remaining on the bottom plate.

  When it is determined that the paper has run out and a large number of sheets are replenished from the second paper storage unit to the first paper storage unit, the paper transferred from the second paper storage unit becomes the first paper storage unit. An abnormality occurs such that the sheet remaining in the sheet storage unit is caught.

  Further, the bottom plate of the first paper storage unit has an opening for detecting the presence or absence of the paper stacked on the upper surface thereof. There is a problem that the replenished paper is caught on the edge of the opening in the paper feeding direction. Further, when a bottom hole of the first paper storage unit is formed with a fitting hole that can be moved up and down with respect to the side fence and allows the side fence to move in the paper width direction, The paper fed to the edge in the paper feeding direction gets stuck. This is because the replenishment unit is not a single sheet but a bundle of stacked sheets. That is, if a single sheet of paper is used, the resistance received from the opening of the bottom plate and the edge of the relief hole is small. This is because the resistance received from the user increases.

  According to the first aspect of the present invention, there is provided a first paper storage unit having a bottom plate supported on the upper and lower sides for loading a large number of papers, and a plurality of papers stacked in parallel with the first paper storage unit. A second paper storage unit having a bottom plate to be separated, a paper supply unit configured to separate and feed the paper stacked in the first paper storage unit one by one in order from the uppermost one, and the first paper An elevation drive unit for elevating and lowering the bottom plate of the storage unit, a transfer drive unit for collectively transferring the sheets of the second paper storage unit to the first paper storage unit, and a bottom plate of the first paper storage unit. A formed paper detection opening, a reflection type optical sensor facing the paper detection opening to detect the presence or absence of paper on the bottom plate of the first paper storage unit, and the second paper storage An actuator that is displaced by the load of the paper placed on the bottom plate of the section, A paper detector that detects the presence or absence of paper on the bottom plate of the second paper storage unit by displacement, and that the paper stored in the first paper storage unit has been exhausted by the output of the optical sensor. If recognized, the first paper storage unit is moved up and down by the elevation drive unit, and the height of the bottom plate of the first paper storage unit is adjusted to the height of the bottom plate of the second paper storage unit. The sheets in the second sheet storage unit are transferred to the first sheet storage unit by the transfer drive unit. Therefore, as long as there is at least one sheet on the bottom plate of the first sheet storage unit, the sheet on the bottom plate is reliably detected by the optical sensor regardless of whether the sheet has a curl. Further, since the detection of the presence or absence of the sheet in the second sheet storage section may be obtained in units of a sheet bundle, it is possible to reliably detect the presence or absence of the sheet by greatly displacing the actuator.

  According to a second aspect of the present invention, in the first aspect of the present invention, the sheet detecting opening is formed in a shape such that an opening width gradually narrows in a sheet feeding direction. Therefore, an edge that gives resistance to the leading edge of the sheet is not formed at the end of the sheet detecting opening on the sheet feeding direction side. In addition, since the opening width of the sheet detection opening gradually narrows in the sheet feeding direction, when the sheets are supplied from the second sheet storage unit to the bottom plate of the first sheet storage unit, the lowermost sheet Even if the leading edge of the paper protrudes from the surface of the bottom plate into the inside of the paper detection opening due to the weight of the paper stacked thereon, the leading edge of the paper is located on the paper feed direction side of the paper detection opening. , It escapes from the paper detection opening as it approaches the end of the paper.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the bottom plate of the first paper storage unit has a relief hole for projecting a side fence that defines a position of a side edge of the paper, The escape hole is defined in a shape in which the opening width gradually becomes narrower in the paper feeding direction. Therefore, an edge that gives resistance to the leading edge of the paper is not formed at the end of the escape hole on the paper feeding direction side. Also, since the opening width of the escape hole becomes gradually narrower in the paper feeding direction, when replenishing the paper from the second paper storage unit onto the bottom plate of the first paper storage unit, the leading edge of the lowermost paper sheet However, even if the paper loaded on it is curved and protrudes from the surface of the bottom plate into the escape hole from the surface of the bottom plate, the leading edge of the paper is moved from the escape hole toward the end of the escape hole on the paper feeding direction side. You will escape.

  According to the first aspect of the present invention, the sheet detecting opening is formed in the bottom plate of the first sheet storing portion, and the sheet on the bottom plate of the first sheet storing portion is opposed to the sheet detecting opening. Since a reflection type optical sensor for detecting the presence or absence is provided, as long as there is at least one sheet on the bottom plate of the first paper storage unit, the paper on the bottom plate is illuminated regardless of whether the paper has a curl. The detection can be reliably performed by the sensor. Therefore, it is possible to solve the problem caused by replenishing the paper despite the fact that the paper remains in the first paper storage unit, and to reliably replenish the paper. Further, since the detection of the presence or absence of the sheet in the second sheet storage section may be obtained in units of a sheet bundle, the presence or absence of the sheet can be reliably detected by greatly displacing the actuator. Thus, an inexpensive mechanical switch such as a micro switch can be used.

  According to the second aspect of the present invention, in the first aspect of the present invention, the sheet detecting opening is formed in such a shape that the opening width gradually narrows in the sheet feeding direction. No edge that gives resistance to the leading edge of the sheet is formed at the end in the sheet feeding direction. In addition, since the opening width of the sheet detection opening gradually narrows in the sheet feeding direction, when the sheets are supplied from the second sheet storage unit to the bottom plate of the first sheet storage unit, the lowermost sheet Even if the leading edge of the paper protrudes from the surface of the bottom plate into the inside of the paper detecting opening due to the weight of the paper stacked thereon, the leading edge of the paper is located on the paper feeding direction side of the paper detecting opening. Can be made to escape from the paper detection opening as it goes toward the end of the paper. This makes it possible to reliably supply paper.

  According to the third aspect of the present invention, in the first or second aspect of the invention, the bottom plate of the first sheet storage portion has an escape hole for projecting a side fence that defines a position of a side edge of the sheet. However, since the clearance hole is formed in such a shape that the opening width gradually narrows in the paper feeding direction, an edge that gives resistance to the leading edge of the paper is formed at the paper feeding direction side end of the clearance hole. Disappears. Also, since the opening width of the escape hole becomes gradually narrower in the paper feeding direction, when replenishing the paper from the second paper storage unit onto the bottom plate of the first paper storage unit, the leading edge of the lowermost paper sheet However, even if the paper loaded on it is curved and protrudes from the surface of the bottom plate into the escape hole from the surface of the bottom plate, the leading edge of the paper is moved from the escape hole toward the paper feed direction end of the escape hole. You can escape. This makes it possible to reliably supply paper.

An embodiment of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a copying machine main body of a copying machine. A tray box 3 having an open upper surface is supported by guide rails 2 provided on both inner side surfaces of the copying machine main body 1 so as to be able to be pulled out in the front-rear direction. ing.
The tray box 3 is provided with a first paper storage unit 4 and a second paper storage unit 5. The first sheet storage unit 4 includes a bottom plate 6 supported so as to be able to move up and down, and side fences 7 for guiding both side edges of the sheets S stacked on the upper surface of the bottom plate 6. The second paper storage unit 5 includes a bottom plate 8 fixedly supported in the tray box 3, side fences 9 for guiding both side edges of the paper S stacked on the upper surface of the bottom plate 8, And a back fence 10 that supports the trailing edge of the sheet S. As shown in FIG. 2, the bottom plate 8 is divided into two parts on the left and right sides, and the back fence 10 is configured to be able to move toward the first paper storage unit 4 between the divided parts.

  Further, as shown in FIG. 1, the tray box 3 is provided with a sheet feeding unit for separating and feeding the sheets S stacked on the bottom plate 6 of the first sheet storage unit 4 one by one in order from the top layer. 11, an elevation drive unit 12 that raises and lowers the bottom plate 6, and a transport that moves the paper S loaded on the bottom plate 8 of the second paper storage unit 5 to the first paper storage unit 4 side and supplies the paper S onto the bottom plate 6. A drive unit 13 is provided.

  As shown in FIGS. 1 and 4, the lifting drive unit 12 includes a plurality of wire hooks 14 protruding from both sides of the bottom plate 6, and a pulley rotatably supported at a fixed position directly above the wire hooks 14. 15, a drive pulley 17 fixed to both ends of a drive shaft 16 provided below the bottom plate 6, a plurality of wires 18 each having one end fixed to each of the drive pulleys 17 and wound therearound, Gears 20 and 21 for transmitting the rotation of the lifting motor 19 to the drive shaft 16 are provided. A wire 18 pulled out of the driving pulley 17 is wound around a pulley 15, and the tip is fixed to a wire hook 14. As shown in FIG. 4, a tongue piece 22 is formed integrally with one of the wire hooks 14, and when the tongue piece 22 blocks the optical axis, the lowermost position (home position) of the bottom plate 6 is set. A lowermost position detection sensor 23 is fixedly provided by a transmission type optical sensor for detecting.

  As shown in FIGS. 1 and 3, the transfer drive unit 13 includes a movable body 25 coupled to a lower end of the back fence 10 and slidably supported by a guide shaft 24 fixed to the tray box 3. An endless belt 26 supported in parallel with the shaft 24 and partially fixed to the movable body 25, a pair of pulleys 27 and 28 around which the belt 26 is wound, and a pulley 28 Gears 31 and 32 for transmitting to a rotating shaft 30 that rotates integrally. As shown in FIG. 3, a tongue piece 33 is integrally formed on one side of the movable body 25, and when the optical axis is blocked by the tongue piece 33, a return position (home position) of the movable body 25 is detected. A return position detection sensor 34 using a transmission type optical sensor is fixedly provided.

As shown in FIG. 1, a paper detection opening 35 is formed in the bottom plate 6 of the first paper storage unit 4, and the bottom plate 6 is disposed on the bottom surface of the tray box 3 below the paper detection opening 35. A reflection type optical sensor 36 for detecting the presence or absence of the upper sheet S is provided.
A paper detection opening 37 is also formed in the bottom plate 8 of the second paper storage unit 5, and a paper detector 39 having an actuator 38 located in the paper detection opening 37 is provided on the lower surface of the bottom plate 8. ing.

  As shown in FIGS. 2 and 3, the paper detection opening 35 formed in the bottom plate 6 of the first paper storage unit 4 has a shape such that the opening width gradually becomes narrower in the paper feeding direction. Have been. On both sides of the bottom plate 6, relief holes 40 for projecting the side fences 7 are formed. These relief holes 40 also have a shape in which the opening width gradually becomes narrower in the paper S feeding direction. Stipulated.

In such a configuration, the drive shaft 16 and the drive pulley 17 rotate by receiving the rotation of the elevating motor 19, but when the elevating motor 19 is rotated forward, the drive shaft 16 and the drive pulley 17 take up the wire 18. The bottom plate 6 is lifted until the uppermost sheet S is detected as reaching a certain height by a sheet feed level sensor (not shown). By driving the paper feed unit 11, the uppermost paper S is separated and fed one by one. In this manner, the paper is fed. During this time, the light emitted from the light emitting element of the optical sensor 36 is The sheet S is reflected by the sheet S through the sheet detection opening 35, and the reflected light is received by the light receiving element of the optical sensor 36, whereby the presence of the sheet S on the bottom plate 6 is recognized. When it is recognized that the sheet S on the bottom plate 6 has run out, the elevating motor 19 is driven to rotate in the reverse direction until the lowermost position detecting sensor 23 detects the tongue piece 22, thereby lowering the bottom plate 6 to the lowermost position. I do. When the state is recognized by the detection signal of the lowermost position detection sensor 23, the transfer motor 29 is driven in the normal rotation direction, so that the movable body 25 moves to the first paper storage unit 4 side together with the back fence 10 and the bottom plate 8 is pressed by the back fence 10 and replenished on the bottom plate 6 of the first sheet storage unit 4.

  In this way, when the paper S in the first paper storage unit 4 is exhausted, the paper S is replenished from the second paper storage unit 5, but the paper S is placed on the bottom plate 6 of the first paper storage unit 4. As long as there is at least one sheet, the sheet S on the bottom plate 6 can be reliably detected by the reflection type optical sensor 36 regardless of whether or not the sheet S has a curl. After recognizing the state, the bundle of sheets S can be collectively supplied from the second sheet storage unit 5 to the first sheet storage unit 4. Thereby, the paper S can be reliably supplied.

  At the time of replenishment of the paper S, the bundle of paper S is slid over the bottom plate 6 in which the paper detection opening 35 is formed and pushed out to the paper feeding position, but the paper detection opening 35 is directed in the paper feeding direction. Therefore, an edge that gives resistance to the leading edge of the sheet S is not formed at the end of the sheet detection opening 35 on the sheet feeding direction side. Further, since the opening width of the sheet detection opening 35 gradually decreases in the sheet feeding direction, the sheet S is supplied from the second sheet storage unit 5 to the bottom plate 6 of the first sheet storage unit 4. Even if the leading edge of the lowermost sheet S is curved and protrudes from the surface of the bottom plate 6 into the inside of the sheet detecting opening 35 with the weight of the sheet S stacked thereon, the leading edge of the sheet S is The paper exits from the paper detection opening 35 toward the end of the paper detection opening 35 on the paper feeding direction side. Therefore, the bundle of sheets S can be reliably supplied from the second sheet storage section 5 to the first sheet storage section 4.

  As shown in FIG. 2, in the present embodiment, the side fence 7 is not configured to move in the width direction according to the size of the sheet S, but the side fence 7 is In the case where the opening width of the escape hole 40 is increased in order to move the escape hole 40 in the width direction of the paper S, a long edge along the width direction of the paper S is conventionally provided at the edge of the escape hole 40 on the paper feeding direction side. However, as in the present embodiment, the opening width of the escape hole 40 is gradually narrowed toward the paper feeding direction. Is not formed. Even if the leading edge of the lowermost sheet S is curved and protrudes from the surface of the bottom plate 6 into the escape hole 40 due to the weight of the sheet S stacked thereon, the leading edge of the sheet S is not As it goes to the end of the paper feed direction 40, it escapes from the escape hole 40.

  As described above, in the first paper storage unit 4, the detection accuracy is enhanced by using the optical sensor 36 so that even a single sheet S can be detected. Can be obtained in units of a bundle of sheets S, so that the presence or absence of the sheet S can be reliably detected by the sheet detector 39 by greatly displacing the actuator 38. Thus, an inexpensive mechanical switch such as a micro switch can be used.

It is a vertical section front view in one embodiment of the present invention. FIG. 4 is a perspective view illustrating a first paper storage unit and a second paper storage unit. It is a perspective view which shows the structure of a transfer drive part. FIG. 4 is a perspective view illustrating a lifting drive unit that raises and lowers a bottom plate of a first paper storage unit and a second paper storage unit.

Explanation of reference numerals

Reference Signs List 4 First paper storage unit 5 Second paper storage unit 6 Bottom plate 7 Side fence 8 Bottom plate 11 Paper feed unit 13 Transfer drive unit 35 Paper detection opening 36 Optical sensor 38 Actuator 39 Paper detector 40 Escape hole S Paper

Claims (3)

A first paper storage unit having a bottom plate supported so as to be capable of lifting and lowering a large number of sheets,
A second paper storage unit that is provided in parallel with the first paper storage unit and has a bottom plate on which a large number of sheets are stacked,
A paper feed unit that separates and feeds the paper loaded in the first paper storage unit one by one in order from the top layer,
An elevating drive unit that elevates the bottom plate of the first paper storage unit,
A transfer drive unit that collectively transfers the sheets of the second sheet storage unit to the first sheet storage unit,
A paper detection opening formed in the bottom plate of the first paper storage unit,
A reflection-type optical sensor that detects the presence or absence of a sheet on the bottom plate of the first sheet storage unit facing the sheet detection opening;
A sheet detector that has an actuator that is displaced by a load of a sheet placed on the bottom plate of the second sheet storage unit, and that detects the presence or absence of a sheet on the bottom plate of the second sheet storage unit by the displacement of the actuator; When,
When it is recognized that the paper stored in the first paper storage unit has run out based on the output of the optical sensor, the first paper storage unit is moved up and down by the elevation drive unit, The height of the bottom plate of one paper storage unit is adjusted to the height of the bottom plate of the second paper storage unit, and the paper in the second paper storage unit is collectively moved by the transfer drive unit to the first paper storage unit. A sheet feeding device, wherein the sheet is transferred to a paper feeding unit.   2. The sheet feeding device according to claim 1, wherein the sheet detecting opening has a shape in which an opening width gradually narrows in a sheet feeding direction. The bottom plate of the first paper storage portion has a relief hole for projecting a side fence that determines the position of the side edge of the paper, and the relief hole has a shape in which an opening width gradually narrows in a paper feeding direction. The sheet feeding device according to claim 1, wherein the sheet feeding device is defined.

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