JP3743296B2 - Paper feeder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper feeding device used for an image forming apparatus such as a printer, a facsimile machine, and a copying machine. In particular, a plurality of sheets (sheet-like recording medium) are set in a sheet feeding unit (set unit) without using a cassette, and the sheet is separated by a pad separation method from the image forming unit of the image forming apparatus. The present invention relates to a paper feeding device that feeds the paper one by one, and regulates the number of sheets (stacking height) according to the type (thickness) of the paper.
[0002]
[Prior art]
Conventionally, a plurality of sheets are set in a stacked state in a stacked state without using a cassette, and the sheets are fed one by one to the image forming unit of the image forming apparatus by a pad separation method. For example, a sheet feeding apparatus as shown in FIG. 4 is known.
This paper feeding device includes a case 1, a paper P set opening 1a provided in the case 1, a paper feed roller 2 provided in the back of the setting opening 1a, a pressing plate 3, and a support plate 4. And.
[0003]
The case 1 is usually formed integrally with the case of the image forming apparatus.
The set port 1a extends in the width direction of the paper (in a direction orthogonal to the paper surface of FIG. 4), and a plurality of sheets P are stacked from the set port 1a in a stacked state (the pressing plate 3 and the support plate 4). Set above).
[0004]
A separation pad 5 for separating and feeding the paper P one by one is pressed against the paper feed roller 2 by a compression coil spring 5a.
[0005]
The pressing plate 3 is rotatably attached to the case 1 with a shaft 3a.
A compression coil spring (hopper spring) 6 is provided between the bottom surface of the pressing plate 3 and the case 1, and the pressing plate 3 is moved by the action of the spring 6 as shown in FIG. Although it is urged to press Pa against the sheet feeding roller 2 from below, this pressing can be released by the operation lever 7 as shown in FIG. The operation lever 7 is fixed to a shaft 8 that is rotatably provided on the case 1, and an arm 7 a is fixed to the shaft 8. Therefore, when the operating lever 7 is rotated to the position shown in FIG. 5A, the arm 7a pushes the pressing plate 3 downward to move it to the release position, and when it is rotated to the position shown in FIG. The press-down due to is released and the pressing plate 3 is moved to the pressing position. That is, the pressing plate 3 can adopt a pressing position (see FIG. (B)) and a releasing position (see FIG. (A)) for releasing the pressing by operating the operation lever 7.
[0006]
The pressure plate 3 and the support plate 4 are provided with side guides 3b and 4a for guiding the side edges of the paper P.
The side guide 3b of the pressing plate 3 is integrally provided with a tongue piece 3c extending inward in the paper width direction, and this tongue piece 3c is the number of stacked sheets P of paper P set in the set part (paper feed part). Is to regulate.
[0007]
In the paper feeding device as described above, the operation lever 7 is operated so that the pressing of the pressing plate 3 is released as shown in FIG. 1A, and the paper P is inserted from the setting port 1a toward the paper feeding roller 2. After that, the operation lever is operated, and the front end Pa of the paper P is pressed against the paper feed roller 2 by the pressing plate 3 as shown in FIG.
Thereafter, when there is a print signal from an unillustrated personal computer or the like to the image forming apparatus, the paper feed roller 2 rotates, and the uppermost paper is supplied toward the press contact portion N between the separation pad 5 and the paper feed roller 2, Here, the next paper that is about to be fed together with the top paper is separated from the top paper by friction with the separation pad 5, and as a result, an image (not shown) one by one in order from the top paper. It will be fed to the forming part.
[0008]
[Problems to be solved by the invention]
According to the above-described conventional apparatus, the means for regulating the number of stacked sheets P is constituted by the tongue piece 3c formed integrally with the side guide 3b. Therefore, the maximum allowable stacking height of the sheets P to be set. h (see FIG. 4) is a constant value defined by the upper surface 3d of the pressing plate 3 and the lower surface 3e of the tongue piece 3c.
Therefore, in both cases, the maximum amount of paper P is set by the user regardless of whether the paper P to be set is a relatively thin paper (such as plain paper) or a relatively thick paper (such as a postcard or an OHP sheet). The number of sheets P corresponding to the allowable stacking height h can be set (for example, in the instruction manual, for postcards and OHP sheets, the stacking height is set to, for example, h / 2 regardless of the presence of the tongue piece 3c. Even if there is an explanation to the extent, the thick sheet P corresponding to the maximum allowable stacking height h can be set).
[0009]
For this reason, in a conventional apparatus, a relatively thick sheet (such as a postcard or an OHP sheet) may be set in excess of an appropriate number (for example, the stacking height h / 2). As described, there was a problem that poor feeding occurred.
That is, as is apparent from FIGS. 4B and 4C, in the apparatus having a structure in which the paper P is pressed against the paper feed roller 2 by the rotating pressing plate 3, the stacking height h ′ of the paper is increased. The entry angle θ of the uppermost sheet P with respect to the back surface 5b of the separation pad 5 increases.
For this reason, when the thick and stiff sheet P enters (or tries to enter) the pressure contact portion N between the paper feed roller 2 and the separation pad 5 with a large entry angle θ, the separation pad 5 is stiff. However, it moves downward more than necessary against the urging force of the compression spring 5a, resulting in poor feeding.
[0010]
The object of the present invention is to solve the above-described problems and regulate the stacking height according to the thickness of the paper to be set, so that even if thick paper is set, feeding failure does not occur. It is to provide a paper device.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the sheet feeding device according to claim 1 is configured to separate a set unit in which a plurality of sheets are set in a stacked state without using a cassette, and a sheet set in the set unit one by one. And a separation pad pressed against the paper feed roller, and a pressing unit that is rotatably provided in the set unit and presses the leading edge of the paper set in the set unit against the paper feed roller. A sheet feeding device including a position and a pressing plate capable of taking a release position for releasing the pressing,
When the pressing plate is in the release position, a restricting portion that restricts the stacking height of the sheets set in the setting portion is provided, and the pressing plate is selectively moved to the pressing position and the releasing position. A first position that allows a relatively high stacking height for setting a relatively thin sheet, and a relatively thick sheet in association with a release operation of the operation lever. And a second position limited to a relatively low stacking height.
According to a second aspect of the present invention, there is provided a sheet feeding device that sets a plurality of sheets in a stacked state without using a cassette, and a sheet feeding that separates and feeds the sheets set in the set section one by one. A roller and a separation pad that is pressed against the paper feed roller, a pressing position that is rotatably provided in the set unit and presses the leading edge of the paper set in the set unit against the paper feed roller, and releases the press A sheet feeding device including a pressing plate capable of taking a release position to perform,
A restricting portion is provided for restricting the stacking height of the sheets set in the setting portion when the pressing plate is in the releasing position, and the pressing plate is pressed against the pressing position and the first or second releasing. A drive mechanism by a motor that selectively moves to a position, and the restriction portion is relatively high for setting a relatively thin sheet in conjunction with the first or second release operation by the drive mechanism A first position that allows the stacking height and a second position that limits the stacking height to a relatively low stacking height are set.
The sheet feeding device according to claim 3 is the sheet feeding device according to claim 1 or 2, wherein the set unit is a set unit in which a sheet is set by inserting the sheet toward the sheet feeding roller, The restricting portion has a guide surface for guiding the leading edge of the paper when the paper is inserted.
[0012]
[Function and effect]
The sheet feeding device according to claim 1 is a sheet feeding unit configured to set a plurality of sheets in a stacked state without using a cassette, and a sheet feeding unit that separates and feeds the sheets set in the setting unit one by one. A roller and a separation pad that is pressed against the paper feed roller, a pressing position that is rotatably provided in the set unit and presses the leading edge of the paper set in the set unit against the paper feed roller, and releases the press And a restricting portion for restricting the stacking height of the sheets set in the set portion when the press plate is in the releasing position. A first position that allows a relatively high stacking height for loading relatively thin paper and a second position that limits a relatively low stacking height for setting relatively thick paper Take Therefore, according to this sheet feeding device, when the sheet set in the setting unit when the pressing plate is in the release position is a relatively thin sheet, the stacking height is the first stacking height. Although a relatively high stacking height is allowed by the restricting portion at the position, if the set paper is a relatively thick sheet, the stacking height is relatively low by the restricting portion at the second position. The stacking height is limited.
Therefore, even when a thick sheet is set, the angle of entry of the sheet into the separation surface of the separation pad does not become too large, and the feeding failure does not occur.
According to the paper feeding device according to claim 2, in the paper feeding device according to claim 1, the setting unit is a setting unit in which paper is set by inserting paper toward the paper feeding roller, Since the restricting portion has a guide surface that guides the leading edge of the paper when the paper is inserted, the guiding action by the guide surface makes it easy to insert the paper and at the same time restricts the stacking height.
According to a third aspect of the present invention, there is provided the paper feeding device according to the first or second aspect, further comprising an operation lever that selectively moves the pressing plate between a pressing position and a release position. Since the restricting portion takes the first position or the second position in conjunction with the operation, the stacking height is restricted according to the thickness of the sheet with a simple structure. It becomes.
According to a fourth aspect of the present invention, in the paper feeding device according to the first or second aspect, driving by a motor that selectively moves the pressing plate between a pressing position and a first or second release position. Provided with a mechanism, and the regulating portion is configured to take the first position or the second position in conjunction with the first or second releasing operation by the driving mechanism. Accordingly, the regulation of the stacking height is automatically performed.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
<First Embodiment>
1A and 1B are views showing a first embodiment of a sheet feeding device according to the present invention, in which FIG. 1A is a schematic front view, and FIG. 1B is a partially omitted b view in FIG. In FIG. 1, the same parts as those in the conventional one shown in FIG.
[0014]
A feature of this embodiment is that a regulating member 10 is provided as a regulating portion that regulates the stacking height according to the thickness of the paper to be set.
The regulating member 10 will be described in detail later. As shown in FIG. 1A, a first position for allowing a relatively high stacking height h1 for setting a relatively thin sheet P1, and FIG. As shown to (a), the 2nd position restrict | limited to the comparatively low lamination height h2 for setting comparatively thick paper (postcard, OHP sheet | seat etc.) P2 is taken.
[0015]
The restricting member 10 is a member having a concave cross-section that is open in the upper part, which is a triangle in FIG. 1A and a quadrangle in FIG. 1B. As shown in FIG. A (main body) 1 is rotatably attached.
A tension spring 13 is stretched between the spring hooking portion 12 of the restricting member 10 and the spring hooking portion 1b of the case 1, and the restricting member 10 is always attached counterclockwise around the shaft 11 by the spring 13. However, the rotation is restricted by the contact between the operation lever 7 and the restriction lever 7b fixed on the same axis 8.
As shown in FIG. 1 (a), the arm 7a fixed on the same axis 8 with the operation lever 7 in this embodiment is configured to push down the pressing plate 3 relatively large, as shown in FIG. As shown in FIG. 2A, a first pressing surface 7a1 and a second pressing surface 7a2 for pressing the pressing plate 3 relatively small are formed.
Further, as shown in FIG. 1A, the restriction lever 7 b has a first push-down portion that turns the restriction member 10 relatively small in the clockwise direction (pushes down) according to the turning angle of the operation lever 7. 2b1 and a second push-down portion 7b2 that rotates (presses down) the restricting member 10 relatively large in the clockwise direction, as shown in FIG. 2A.
[0016]
Therefore, when the operating lever 7 is rotated to the position shown in FIG. 1A, the pressing plate 3 is pushed down relatively large and the regulating member 10 is pushed down relatively small, so that the upper surface 3d (or support) of the pressing plate 3 is supported. The upper surface 4d) of the plate 4 and the lower end 10a of the restricting member 10 form a relatively high stacking allowable height h1 for setting a relatively thin sheet P1, and an operation lever at the position shown in FIG. 7 is rotated, the pressing plate 3 is pressed down relatively small and the regulating member 10 is pushed down relatively large, and the upper surface 3d of the pressing plate 3 (or the upper surface 4d of the support plate 4) and the lower end 10a of the regulating member 10 are pressed. Thus, a relatively low stacking allowable height h2 (for example, a height of about (h1) / 2) for setting the relatively thick paper P2 is formed.
[0017]
The paper P setting unit is configured such that the paper P is set by inserting the paper P from the setting port 1a toward the paper feed roller 2, and the leading end of the paper is placed on the regulating member 10 when the paper is inserted. A guide surface 10b for guiding is formed.
Accordingly, the sheet can be easily inserted by the guiding action of the guide surface 10b of the restricting member 10, and at the same time, the stacking height h1 or h2 is restricted.
[0018]
After the paper P is set, the operation lever 7 is operated so that the paper is pressed against the paper feed roller 2 by the pressing plate 3 as shown in FIG. 2B (the paper P is omitted in the figure). Thereafter, when there is a print signal from a personal computer (not shown) to the image forming apparatus, the paper feed roller 2 rotates and the uppermost paper is directed to the pressure contact portion between the separation pad 5 and the paper feed roller 2. The next paper that is about to be fed together with the top paper is separated from the top paper by friction with the separation pad 5, and as a result, one by one in order from the top paper. Then, it is fed to an image forming unit (not shown).
[0019]
According to the sheet feeding device as described above, the following operational effects can be obtained.
(A) A setting unit in which a plurality of sheets P are set in a stacked state without using a cassette, a sheet feeding roller 2 that separates and feeds the sheets P set in the setting unit one by one, and the feeding A separation pad 5 that is pressed against the paper roller 2, a pressing position that is rotatably provided at the setting unit and presses the leading edge Pa of the paper P set on the setting unit against the paper feeding roller 2, and a release that releases the pressing And a restricting portion 10 that restricts the stacking height of the paper P set in the set portion when the press plate 3 is in the release position. A first position for allowing a relatively high stacking height h1 (see FIG. 1A) for setting a relatively thin sheet P1, and a section 10 for setting a relatively thick sheet P2. Relatively low stacking height h 2 (see FIG. 2A), the sheet feeding device allows the sheet to be set in the set unit when the pressing plate 3 is in the release position. Is a relatively thin sheet P1, the stacking height is allowed to be a relatively high stacking height h1 by the restriction unit 10 in the first position, but the sheet P2 to be set is a relatively thick sheet P2. In this case, the stacking height is limited to a relatively low stacking height h2 by the restricting portion 10 in the second position.
Therefore, even when the thick paper P2 is set, the paper entrance angle θ (see FIG. 4C) to the separation surface 5b of the separation pad 5 does not become too large, and the feeding failure does not occur.
(B) The setting unit is a setting unit in which the paper P is set by inserting the paper P toward the paper feed roller 2, and the regulation unit 10 includes a guide surface 10b that guides the leading edge of the paper when the paper is inserted. Therefore, the sheet P is easily inserted by the guide action by the guide surface 10b, and at the same time, the stacking height h1 or h2 is regulated.
(C) An operation lever 7 for selectively moving the pressing plate 3 between the pressing position and the release position is provided, and the restricting portion 10 is interlocked with the release operation of the operation lever 7 at the first position (FIG. )) Or the second position (see FIG. 2A), the stacking height is regulated according to the thickness of the paper P with a simple configuration.
[0020]
<Second Embodiment>
FIG. 3 is a partially omitted side view showing the second embodiment of the paper feeding device according to the present invention (a view corresponding to the view b in FIG. 1A). In FIG. 3, the same parts as those in the first embodiment shown in FIG.
The feature of this embodiment is that the pressing plate 3 is selectively moved between a pressing position and a first releasing position (see FIG. 1A) or a second releasing position (see FIG. 2A). A drive mechanism 20 by a motor M is provided, and the regulating member 10 is moved to a first position (see FIG. 1A) or a second position (in conjunction with the first or second release operation by the drive mechanism 20). 2 (a)).
Specifically, the motor M is formed of a step motor, and a gear 21 fixed to the output shaft is meshed with a gear 22 fixed to the shaft 8.
Then, for example, the rotation speed of the motor M at the time of releasing the pressure is determined in conjunction with a paper type selection switch provided on an operation panel (not shown) of the image forming apparatus, and for example, plain paper is selected by the operation panel. In this case, when the pressing of the pressing plate 3 is released, the motor M rotates by the first number of rotations, and the shaft 8 rotates in response thereto, so that the pressing plate 3 and the regulating member 10 are in the first releasing position. (See FIG. 1A.) When a thick sheet such as a postcard or an OHP sheet is selected by the operation panel, when the pressing of the pressing plate 3 is released, the motor M is The shaft 8 rotates according to the number of rotations of 2, and the pressing plate 3 and the regulating member 10 are configured to be in the second release position (see FIG. 2A).
Therefore, in this embodiment, the operation lever 7 is not necessarily provided as shown in FIG.
According to such an embodiment, the drive mechanism 20 by the motor M that selectively moves the pressing plate 3 to the pressing position and the first or second release position is provided, and the first or Since the restricting member 10 is configured to take the first position or the second position in conjunction with the second releasing operation, the stacking height is automatically regulated according to the thickness of the paper. It will be.
[0021]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope of the gist of the present invention.
[0022]
【The invention's effect】
According to any one of the first to fourth embodiments, even when a thick sheet is set, the paper entry angle to the separation surface of the separation pad does not become too large, and the feeding failure does not occur.
further,
According to the paper feeding device of the second aspect, it becomes easy to insert the paper, and at the same time, the stacking height is regulated.
According to the sheet feeding device of the third aspect, the stacking height is regulated according to the sheet thickness with a simple configuration.
According to the paper feeding device of the fourth aspect, the stacking height is automatically regulated according to the thickness of the paper.
[0023]
[Brief description of the drawings]
1A and 1B are diagrams illustrating a first embodiment of a paper feeding device according to the present invention, in which FIG. 1A is a schematic front view, and FIG. 1B is a partially omitted b view in FIG.
FIGS. 2A and 2B are explanatory diagrams of operation. FIGS.
FIG. 3 is a partially omitted side view showing a second embodiment of a paper feeding device according to the present invention (a view corresponding to a view from b in FIG. 1A).
FIGS. 4A to 4C are explanatory diagrams of the prior art.
[Explanation of symbols]
P Paper P1 Relatively thin paper P2 Relatively thick paper 2 Paper feed roller 3 Press plate 5 Separation pad 7 Operation lever 10 Restriction member (regulation part)
h1 relatively high stacking height h2 relatively low stacking height 10b guide surface M motor 20 drive mechanism

Claims (3)

A set unit in which a plurality of sheets are set in a stacked state without using a cassette, a sheet feed roller that separates and feeds sheets set in the set unit one by one, and is pressed against the sheet feed roller A separating plate, a pressing plate that is rotatably provided in the setting unit, and that can take a pressing position that presses the leading edge of the paper set in the setting unit against the paper feeding roller, and a release position that releases the pressing. A paper feeding device comprising:
A restricting portion for restricting the stacking height of the sheets set in the set portion when the pressing plate is in the release position is provided, and the pressing plate is selectively moved to the pressing position and the releasing position. A control lever is provided, and in conjunction with the release operation of the control lever, the restricting portion allows a relatively high stacking height for setting a relatively thin sheet, and a relatively thick sheet. And a second position for limiting the stacking height to a relatively low stacking height. A set unit in which a plurality of sheets are set in a stacked state without using a cassette, a sheet feed roller that separates and feeds sheets set in the set unit one by one, and is pressed against the sheet feed roller A separating plate, a pressing plate that is rotatably provided in the setting unit, and that can take a pressing position that presses the leading edge of the paper set in the setting unit against the paper feeding roller, and a release position that releases the pressing. A paper feeding device comprising:
A restricting portion is provided for restricting the stacking height of the sheets set in the setting portion when the pressing plate is in the releasing position, and the pressing plate is pressed against the pressing position and the first or second releasing. A drive mechanism by a motor that selectively moves to a position, and the restriction portion is relatively high for setting a relatively thin sheet in conjunction with the first or second release operation by the drive mechanism A sheet feeding device having a first position allowing a stacking height and a second position limiting a relatively low stacking height for setting a relatively thick sheet.   The set unit is a set unit in which a sheet is set by inserting a sheet toward the paper feed roller, and the restricting unit has a guide surface that guides the leading end of the sheet when the sheet is inserted. The sheet feeding device according to claim 1, wherein:

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