JP2000191146A - Paper feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeder capable of certainly positioning a paper sheet and improving paper feeding performance. SOLUTION: A front side aligning part has a front side aligning part upper side 5a-1 and a front side aligning part lower side 5a-2. In the same way, a rear side aligning part also has a rear side aligning part upper side 6a-1 and a rear side aligning part lower side 6a-2. When the number of paper sheets to place on a bottom plate is small, only the front side aligning part upper side 5a-1 and the rear side aligning part lower side 6a-2 push the side of the sheet to the side of a side fence and align it. A pressurizing surface (sheet aligning surface) of the front side aligning part upper side 5a-1 is made of a raising surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeding apparatus applied to an image forming apparatus such as a copying machine, a printer, a facsimile, and the like, and more particularly, to an improvement in a technique for aligning the side (width) of paper.

[0002]

2. Description of the Related Art Generally, a paper feed tray (paper feed cassette) of a paper feeder includes a bottom plate for receiving stacked sheets, a pair of side fences, and an end fence. The bottom plate is
In general, a large-capacity sheet feeding apparatus moves up and down horizontally, and a cassette type sheet feeding apparatus generally rotates up and down on the tip side. In a dedicated sheet cassette for each sheet size, a pair of side fences are fixed in advance at positions corresponding to the sheet size, and sheets are set between both side fences.

On the other hand, in a so-called universal cassette in which sheets of a plurality of sizes can be set, one side fence or both side fences can be moved according to the sheet size. It has become.

However, in a paper feeding device in which the position of the side fences can be adjusted, the positioning accuracy can be improved by the adjustment, but the length (width) between the side fences varies due to a variation in operation by the user. May occur. Conventionally, a side shift member has been known as a means for solving such a problem.
This is achieved by attaching one end of an elastic plate-like member called a side shift member to at least one side fence, and pressing the side of the sheet with a free end (the other end) floating (separating) from the side fence. , To attempt to position the paper. As this type of technology, for example, Japanese Patent Application Laid-Open No. 5-58478 is known.

[0005]

However, since the proper pressing force of the side shifting member to the sheet depends on the number of stacked sheets, sufficient performance can be obtained with the conventional side shifting member having a unique elastic force. Did not. In other words, it is difficult to achieve both a pressure contact force large enough to position the sheet when the sheet is fully loaded and a pressure contact force small enough not to bend the sheet when a small number of sheets are stacked. Therefore, there is a drawback that the positioning performance of sheet feeding is affected by the number of stacked sheets.

In particular, if a large pressing force is applied to sheets when a small number of sheets are stacked, the sheets may be broken, causing damage to the sheets,
An image forming position shifts. Further, this fold is likely to occur in a high-humidity environment and when the paper is thin.
For this reason, there is a problem that the paper must be limited and the use environment must be limited. SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet feeding device capable of reliably positioning a sheet and improving sheet feeding performance.

[0007]

According to a first aspect of the present invention, there is provided a bottom plate on which sheets are stacked, and a pair of side fences for positioning a side of the sheets. On the other hand, in a paper feeder provided with a paper feed tray having a side shifting member for pushing and positioning a side of a sheet by its elasticity, a paper pressing surface of the side shifting member is a raised surface.

[0008] In order to achieve the above object, a second aspect is provided.
The invention described above is provided with a bottom plate on which sheets are stacked, a pair of side fences for positioning the sides of the sheets, and a sheet feeding member having at least one of the side fences with a side shift member for pressing and positioning the sides of the sheets by elasticity thereof. In a paper feeder provided with a tray, a bottom plate facing a paper pressing surface of a side shift member has a convex portion or a concave portion.

In order to achieve the above object, a third aspect of the present invention is provided.
The invention described above is provided with a bottom plate on which sheets are stacked, a pair of side fences for positioning the sides of the sheets, and a sheet feeding member having at least one of the side fences having a side shift member for pressing and positioning the sides of the sheets by elasticity thereof. In the sheet feeding device provided with the tray, the side shift member is configured by a plurality of pressing surfaces having different pressing forces, is fixed to one pressing surface, and has a guide sheet that covers a gap between the other pressing surface and the two pressing surfaces. It is characterized by the following.

[0010] In order to achieve the above object, the present invention relates to claim 4.
The invention described above is provided with a bottom plate on which sheets are stacked, a pair of side fences for positioning the sides of the sheets, and a sheet feeding member having at least one of the side fences with a side shift member for pressing and positioning the sides of the sheets by elasticity thereof. In a paper feeder provided with a tray, the side shift member has a plurality of pressurized surfaces with different pressing pressures, and in a state where there is no paper on the bottom plate or in a state where a small number of sheets are stacked, the bottom plate is It is characterized by facing the low pressure surface.

According to another aspect of the present invention, the above object is achieved.
The invention described above is provided with a bottom plate on which sheets are stacked, a pair of side fences for positioning the sides of the sheets, and a sheet feeding member having at least one of the side fences with a side shift member for pressing and positioning the sides of the sheets by elasticity thereof. In a sheet feeder provided with a tray, a pressing surface for pressing the uppermost sheet in the side shift member is provided so as to be slidable up and down.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a top view of a paper feed tray having a side shifting member, FIG. 2 is a top view of a side fence and a side shifting member, and FIG. 3 is a detailed external perspective view of the side shifting member.
As shown in FIG. 1, a bottom plate 2 for stacking paper is provided inside a paper feed tray 1 so as to be rotatable about a fulcrum 2a. Further, inside the paper feed tray 1, side fences 3, 4 for regulating the side of the paper are provided. In this example, side shifting members 5 and 6 for pushing the side of the sheet and shifting the sheet to the other side fence 3 are attached to one side fence 4. 10 is an end fence.

As shown in FIG. 2, the front side shift member 5 having elasticity includes a front side shift portion 5a and a front elastic piece 5a.
b. The rear side shifting member 6 also having elasticity has a rear side shifting portion 6a and a rear elastic piece 6b. One end of each of the elastic pieces 5b and 6b is a side fence 4.
The other end of the elastic pieces 5b, 6b to which the side shift portions 5a, 6a are attached is floated inward from the side fence 4 (the side fence 4). Away from the inner surface) and at the free end. Therefore, the side shift portions 5a and 6a can swing in the direction approaching and moving away from the side fence 4 by the spring property.

Further, the front side shifting portion 5a has
As shown in FIG. 5, there is a front side shift portion upper side 5a-1 and a front side shift portion lower side 5a-2. Similarly, the rear side shift portion 6a includes a rear side shift portion upper portion 6a-1 and a rear side shift portion 6a-2. When the number of stacked sheets on the bottom plate 2 is small, only the front side shifter upper part 5a-1 and the rear side shifter lower part 6a-2 push the sheet side toward the side fence 3 to perform the shift.

When the number of sheets is small, the bottom plate 2
The bottom plate 2 is inclined so that the front side (the front end side) of the front side is at the upper position, and the front guide shifting portion 5 faces the sheet.
This is because in the case of a, the upper side is 5a-1, and in the case of the rear guide shift portion 6a on the shaft support side of the bottom plate 2, the lower side 6a-2.

When the number of stacked sheets is small, the stiffness in the width direction of the sheet is also weak, so the sheet pressing force at the upper side 5a-1 of the front guide shifter and the lower side 6a-2 of the rear side shifter is:
It is necessary to have a small force so that the sheet does not bend. When the paper is fully loaded on the bottom plate 2 or in a state close to it, the upper side 5a-1 and the upper side 5a are located in the front side shifter 5a and the rear side shifter 6a, respectively.
1. The lower side 5a-2, 6a-2 pushes the side of the sheet to perform shifting.

In the example shown in FIG. 3, the upper side 5a-1 of the front side shift portion has an upper elastic piece 5b-1 and the lower side 5a-2 has a lower elastic piece 5b-2. An elastic piece upper side 6b-1 is provided on the shifting part upper side 6a-1, and a lower side 6a-2.
Has an elastic piece lower side 6b-2. Since the upper and lower resilient pieces have different spring constants, the paper can be smoothly moved regardless of the amount of paper loaded.

However, as described above, since the spring force of the elastic pieces of the upper front side shift portion 5a-1 and the lower rear side shift portion 6a-2 cannot be increased, the number of loaded paper sheets is small and the humidity is high. When thin paper is used in the environment, paper positioning accuracy is poor. Therefore, the configuration shown in FIG.

FIG. 4 is a diagram showing an example in which the pressing surface on the upper side of the front side shift portion is a raised surface, and FIG. 5 is a diagram showing a state in which the paper is shifted on the raised surface. Front side shifter upper part 5
The pressing surface (paper shifting surface) a-1 is a raised surface 7. Therefore, as shown in FIG. 5, even if the paper P is brought close to the raised surface 7, the paper P will not be broken, and the paper P will not be damaged. Further, since the paper P can be appropriately shifted, the image forming position can be stabilized. Further, in this method, the pressing force of the side shift member can be set to be strong, so that thicker or larger paper can be passed.
It is possible to handle paper widths from thin to thick paper and to handle many sizes.

FIG. 6 is a view showing an example in which a concave portion is provided in a bottom plate portion facing the upper side of the front side shift portion. As shown in FIG. 6, since the bottom plate 2 has the concave portion 8, the sheet P is formed into an arc shape in accordance with the shape of the bottom plate, and is folded into the sheet P by the pressing force of the upper front side shift portion 5 a-1. Can be prevented from occurring. This is effective when the paper is thin, and enables the use of thinner paper.

FIG. 7 is a view showing an example in which a convex sheet is provided on a bottom plate portion facing the upper side of the front side shift portion. FIG. 8 is a diagram showing a state in which many sheets are stacked on the bottom plate shown in FIG. As shown in FIG. 7, the bottom plate 2 is provided with a pair of convex-shaped sheets 9 (9a, 9b) whose ends facing each other are urged upward, and has the same effect as that shown in FIG. Bring. In addition, as shown in FIG. 8, when the number of stacked sheets is large, the convex-shaped sheet 9 loses the weight of the sheet P and becomes flat. This is to prevent the paper P from being deformed by applying no extra stress to the paper P in the paper storage state.

FIG. 9 is a view showing that no break occurs when the paper P is arc-shaped. 6 and 7, the bottom plate 2
By loading paper on the upper side, the front side shift portion upper side 5a
If the paper portion facing -1 is in an arc shape, the paper will not be bent.

FIG. 10 is a diagram showing an example in which a guide sheet is fixed to the pressing surface on the upper side of the front side shift portion, and FIG. 11 is a diagram showing how the guide sheet is deformed by paper. FIG.
As shown in FIG. 0, the guide sheet 11 is fixed to the pressing surface of the upper front side shift portion 5a-1. The guide sheet 11 covers the lower side 5a-2 of the front side shift portion. Since the guide sheet 11 is thin, as shown in FIG. 11, the guide sheet 11 is bent by the paper P so as to enter between the upper side 5a-1 and the lower side 5a-2. Also, when the number of sheets is small, the bending is eliminated. Therefore, since the guide sheet 11 moves in the vertical direction of the front side shift portion lower side 5a-2, the vertical movement of the sheet P between the pressing surfaces by the bottom plate 2 is smooth,
It is possible to prevent the paper P from being damaged by being caught or the like.

FIG. 12 is a diagram showing the positional relationship between the bottom plate and the side shift portion in a state where sheets are set or only a small number of sheets are set. The bottom plate 2 is urged upward about the fulcrum 2a by the spring 12, and when no paper is set or when a small number of sheets are set, the leading end thereof moves upward. As described above, the front side shift portion upper side 5a-1 and the rear side shift portion lower side 6a
-2. Since the elastic force of these shift portions is weak, even if a small number of sheets are additionally set on the bottom plate 2 in this state, the sheets will not be bent.

FIG. 13 is a view showing an example in which the upper side of the front side shift portion is attached to an elastic piece so as to be vertically movable. Elastic piece 5b
-1, a guide plate 14 is attached, and the upper front side shift portion 5a-1 is held by the guide plate 14 so as to be vertically movable. Therefore, if the upper side 5a-1 of the front side shift unit is moved up and down in accordance with the paper stacking height, the top surface of the top paper can be reliably pressed by the paper pressing unit 13,
Floating and folding of the paper can be prevented. For this reason,
It is possible to prevent the paper from being damaged and the image forming position from shifting.

Further, since the uppermost sheet is reliably pressed by the sheet pressing section 13 regardless of whether the bottom plate 2 is at the sheet feeding position or the sheet setting position, the sheet feeding tray 1 accompanied by vibration is subjected to image formation. Even when the sheet is set in the apparatus main body, it is possible to prevent the sheet from being disturbed.

FIG. 14 is a diagram showing a state in which the elastic piece shown in FIG. Since the elastic piece 5b-1 restricts the upper side 5a-1 of the front side shift portion from above by the end surface of the U-shaped portion of the upper surface, even when a large number of sheets are stacked, the upper side 5a-1 of the front side shift portion 5b-1.
The sheet can be surely pressed down by the first sheet pressing section 13. By the way, with the shape of the elastic piece shown in FIG.

[0029]

According to the first aspect of the present invention, since the side shifting member has the raised pressing surface, an appropriate pressure can be applied to the side of the sheet when a small number of sheets are stacked, and the image forming position. Can be stabilized.

According to the second aspect of the present invention, the bottom plate opposed to the paper pressing surface of the side shift member has the convex or concave portion, so that the same effect as above can be obtained.

According to the third aspect of the present invention, the side shift member is composed of a plurality of pressing surfaces having different pressing forces, is fixed to one of the pressing surfaces, and covers a gap between the other pressing surface and the two pressing surfaces. Since the guide sheet is provided, the paper can be smoothly moved across the plurality of pressure surfaces, and the paper can be prevented from being damaged.

According to the fourth aspect of the present invention, when a small number of sheets are set, the sheets are positioned on the low pressure surface of the side-shifting member, so that the sheets are not broken and the transport quality is reduced. Stability and stability of the image forming position can be achieved.

According to the fifth aspect of the present invention, the pressing surface can be moved in accordance with the uppermost sheet, and the sheet can be reliably moved.

[Brief description of the drawings]

FIG. 1 is a top view of a sheet feeding tray having a side shifting member.

FIG. 2 is a top view of a side fence and a side shifting member.

FIG. 3 is a detailed external perspective view of a side shift member.

FIG. 4 is a diagram illustrating an example in which a pressing surface on the upper side of a front side shift portion is a raised surface.

FIG. 5 is a diagram illustrating a state in which a sheet is being shifted on a raised surface.

FIG. 6 is a view showing an example in which a concave portion is provided in a bottom plate portion facing the upper side of the front side shift portion.

FIG. 7 is a diagram showing an example in which a convex-shaped sheet is provided on a bottom plate portion facing the upper side of the front side shift portion.

8 is a diagram illustrating a state in which a large number of sheets are stacked on the bottom plate illustrated in FIG. 7;

FIG. 9 is a diagram showing that folding does not occur if the paper is arc-shaped.

FIG. 10 is a diagram illustrating an example in which a guide sheet is fixed to a pressing surface on the upper side of a front side shift portion.

FIG. 11 is a diagram showing how a guide sheet is deformed by paper.

FIG. 12 is a diagram showing a positional relationship between a bottom plate and a side shift portion in a state where no sheets are set or only a small number of sheets are set.

FIG. 13 is a view showing an example in which the upper side of the front side shift portion is attached to an elastic piece so as to be vertically movable.

14 is a diagram showing a state in which the elastic piece shown in FIG. 13 regulates the upper side of the front side shift portion.

FIG. 15 is a diagram illustrating an example in which the top sheet cannot be moved depending on the shape of the elastic piece.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 paper feed tray 2 bottom plate 2 a fulcrum 3, 4 side fence 5 front side shift member 5 a-1 front side shift member upper side 5 a-2 front side shift member lower side 5 b elastic piece 6 rear side shift member 6 a-1 rear side shift member Upper side 6a-2 Rear side shift member lower side 6b Elastic piece 7 Brushed surface 8 Concave part 9 Convex-shaped sheet 10 End fence 11 Guide sheet 12 Spring 13 Paper press part 14 Guide plate

Claims (5)

[Claims] 1. A sheet feeding apparatus comprising: a bottom plate on which sheets are stacked; and a pair of side fences for positioning the sides of the sheets. At least one of the side fences has a side shift member for pressing and positioning the sides of the sheets by elasticity thereof. A sheet feeder provided with a tray, wherein a sheet pressing surface of a side shift member is a raised surface. 2. A sheet feeding apparatus comprising: a bottom plate on which sheets are stacked; and a pair of side fences for positioning the sides of the sheets. At least one of the side fences has a side shifting member for pressing and positioning the sides of the sheets by elasticity thereof. A sheet feeding device provided with a tray, wherein the bottom plate facing the sheet pressing surface of the side shift member has a convex portion or a concave portion. 3. A sheet feeder comprising: a bottom plate on which sheets are stacked; and a pair of side fences for positioning the sides of the sheets. At least one of the side fences has a side shift member for pressing and positioning the sides of the sheets by its elasticity. In a sheet feeding device provided with a tray, the side shift member includes a plurality of pressing surfaces having different pressing forces, is fixed to one pressing surface, and has a guide sheet that covers a gap between the other pressing surface and the two pressing surfaces. A sheet feeding device, characterized in that: 4. A sheet feeder comprising: a bottom plate on which sheets are stacked; and a pair of side fences for positioning the sides of the sheets. At least one of the side fences has a side shift member for pressing and positioning the sides of the sheets by its elasticity. In a paper feeder provided with a tray, the side shift member has a plurality of pressurized surfaces with different pressing pressures, and when there is no paper on the bottom plate or when a small number of sheets are stacked, the bottom plate is A sheet feeding device facing a low pressure surface. 5. A sheet feeder comprising: a bottom plate on which sheets are stacked; and a pair of side fences for positioning the sides of the sheets. At least one of the side fences has a side shift member for pressing and positioning the sides of the sheets by its elasticity. A sheet feeding device provided with a tray, wherein a pressing surface on a side shift member for pressing an uppermost sheet is slidably provided up and down.