JPH04214549A - Pressure contact device for original - Google Patents

Abstract

PURPOSE:To inexpensibly and easily prevent falling of an original pressure plate pressing an original mounted on an original platen. CONSTITUTION:This pressure contact device is provided with a first original pressure contact plate 3a capable of pressing the original mounted on the original platen glass 2, a second original pressure contact plate 3b with one end part rotatably connected to the above mentioned first original pressure contact plate and with the other end attached rotatably to the above mentioned device main body and capable of pressing the original mounted on the original platen, and a rotation control means restricting quantity of rotation of the above mentioned first original pressure contact plate according to the quantity of rotation of the above mentioned second original press-fixing plate.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an original pressing device for pressing an original onto an original table glass, and more particularly to a mechanism for preventing the original pressing plate from falling in an original pressing device used in an image forming apparatus such as a copying machine.

0002

2. Description of the Related Art Conventionally, a document pressure bonding plate is of a type that can be used for both sheet document and book document. A second part has been proposed, which is openably and closably connected to the main body of the copying machine and has a second part whose other edge is openably and closably connected to the main body of the copying machine. The means for preventing the original crimp plate from falling in this configuration includes a weight balance method in which a force is generated from a spring and a link mechanism to offset the own weight of the crimp plate depending on the open state, or a weight balance method in which a force is generated from a spring and a link mechanism, or the
A hook-shaped locking part provided on the upper surface of the copying machine body engages with an engaging part vertically provided on the second part side of the part to prevent the second part from falling over which is connected to the first part. There is something.

Furthermore, in the above method, the locking member is attached to the main body so as to be able to swing at a slight angle, and the locking member is attached to the second
When the section is closed from an open state, the locking part is pushed down and configured so as not to interfere with the first part of the pressure bonding plate, or the locking member is configured to be able to move in and out of the document loading surface of the main body. An improved structure has been proposed in which the locking part is attached to the main body in the state of the document and the locking part retracts when the original is set so that it does not become an obstruction.

0004

[Problems to be Solved by the Invention] However, in the conventional weight balance type, the first and second parts of the pressure bonding plate are connected so as to be swingable. , it is necessary to have one end pivoted to the copying machine main body side, the other end to extend to or near the free end of the first portion of the crimp plate, and a large arm for lifting the free end. In addition, a stopper mechanism and a portion for hooking these mechanisms are formed around the pressure bonding plate, which is undesirable in terms of use and appearance, and the mechanism is complicated and expensive.

On the other hand, in the method in which the locking part provided on the copying machine body and the engaging part of the first part of the crimp plate prevent it from falling, although the structure is simple and inexpensive, the second part of the crimp plate When the first part is opened and the first part is opened, it cannot be prevented from falling. Therefore, if you let go of your hand in this state, the first crimp plate may open wide and fall over, or the members around the opening/closing axis may prevent the crimp plate from rotating. It may be damaged by the moment. Further, due to its structure, the locking portion is located on the front side (with respect to the opening/closing shaft of the second portion), which not only becomes an obstacle when setting a document but also has an unfavorable appearance.

The present invention has been made to solve the problems of the prior art described above, and its purpose is to prevent the original pressing plate that presses the original placed on the original table glass from falling. It is an object of the present invention to provide a document pressing device which is inexpensive and can easily prevent the problem.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a document pressing device for pressing a document onto a document table glass. a first document pressure bonding plate capable of pressing the first document pressure bonding plate, and one end portion of the first document pressure bonding plate rotatably connected to the first document pressure bonding plate;
a second original pressing plate whose other end is rotatably attached to the apparatus main body and capable of pressing the original placed on the original table glass; Said first
A rotation control means for regulating the amount of rotation of the document pressure bonding plate is provided.

Further, in a preferred embodiment, when the first and second document pressure plates are opened, each of the first and second document pressure plates is rotated about a rotation axis of the second document pressure plate on the apparatus main body side. The rotational moment of the second original pressure bonding plate is approximately equal, or the rotational moment of the second document pressure bonding plate is greater than the rotational moment of the first document pressure bonding plate so that the second document pressure bonding plate is in the opening direction. It is characterized by

[0009]

[Operation] According to the present invention, the opening of the first original pressing plate is regulated according to the amount of rotation of the second original pressing plate, and at the same time, the opening of the first original pressing plate and the second original pressing plate are regulated. It is possible to prevent the original pressure bonding plate from falling by making the rotational moment of the second document pressure bonding plate substantially equal to that of the pressure bonding plate or by increasing the rotational moment of the second document pressure bonding plate so that it is in the direction in which the second document pressure bonding plate opens. .

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on the illustrated embodiments.

FIG. 1 is a sectional view showing the configuration of a document pressing device according to this embodiment, and FIG. 2 is a perspective view showing the document pressing device shown in FIG. 1 applied to a copying machine.

In these figures, 1 is the main body of the copying machine, 2
A copy original is placed on a glass original table, and the light emitted from the internal light source of the copying machine main body 1 is transmitted therethrough, thereby making it possible to read the original. Reference numeral 3 denotes an original pressing plate for pressing the original on the original table glass 2, and is composed of a first original pressing plate 3a and a second original pressing plate 3b. Reference numeral 4 denotes a connecting portion that rotatably connects the first original pressing plate 3a and the second original pressing plate 3b, and 5 connects one end of the second original pressing plate 3b to the copying machine main body 1. This is a connecting part that connects rotatably. Reference numeral 6 denotes a pressure bonding sheet that uniformly presses the original on the original platen glass 2 to bring the original into close contact with the original platen glass 2. The movable member 11 is slidably supported by walls 12 and 13 that protrude inwardly from the second original pressure bonding plate 3b, and is attached to the central axis of the opening/closing connecting portion 5 of the second document pressure bonding plate 3b with respect to the copying machine main body 1. Can move in cross directions.

A receiving portion 31 is formed at the end of the first document pressure bonding plate 3a on the rotation fulcrum side, and as shown in FIG.
When the moving member 11 moves toward the first original pressure bonding plate 3a and the first document pressure bonding plate 3a rotates around the connecting portion 4, the receiving portion 31 is brought into contact with the tip portion 11a of the moving member 11. In relation to this, it functions as a stopper that restricts the opening of the first document pressure bonding plate 3a. Note that the tip end 11 of the moving member 11
A is rounded to prevent damage to the receiving portion 31 when the first document pressure bonding plate 3a rotates and comes into contact with the receiving portion 31.

[0014] Connecting portion 5 supporting second original pressure bonding plate 3b
A guide portion 32 is formed on one side of the movable member 11 and comes into contact with the distal end portion 11b of the moving member 11. The shape of the guide portion 32 is such that as the second original pressure bonding plate 3b is opened, the distance between the contact point of the tip portion 11b of the moving member 11 and the rotation center of the connecting portion 5 gradually increases. As the original pressure bonding plate 3b opens, the moving member 11 moves toward the first document pressure bonding plate 3.
It is designed to move to side a. Therefore, the tip end 11 of the movable member 11 is
a protrudes, and as a result, the opening angle of the first document pressure bonding plate 3a gradually becomes smaller. In other words, the opening of the first original pressing plate 3a is regulated according to the opening amount of the second original pressing plate 3b.

[0015] The above-mentioned connecting parts 4 and 5 are connected to the first and second
In order to support the original pressure bonding plate, screws and nuts, snap pins, etc. may be used, or synthetic resin may be used as the material and its deflection may be utilized, and the structure may be such that it can be attached and detached. When copying a large-sized original, the first and second original pressing plates 3a and 3b may be made removable from the copying machine main body 1. Furthermore, although the guide portion 32 is formed on one side of the connecting portion 5, this guide portion does not necessarily have to be integrated with the connecting portion 5, and may be provided separately from the connecting portion 5, or may be attached to the main body of the copying machine. It may be configured integrally with the top cover of No. 1 or may be detachably attached.

Next, referring to FIG. 4, the first original pressure bonding plate 3
The relationship between rotational moment a and second document pressure bonding plate 3b will be explained.

First, by appropriately determining the shape of the guide portion 32, it is possible to obtain the relationship Wa×La≒Wb×Lb.

[0018] Here, Wa and Wb are the first and second
is the total weight of the original pressure bonding plates 3a and 3b, Ga and Gb are their centers of gravity, and La and Lb are the lengths of the moment arms about the center of rotation of the connecting portion 5, respectively. In a state where the above relational expression is satisfied, the first and second original pressure bonding plates 3a, 3
b is kept in balance, and there is sliding resistance between each member,
Static friction is also acting on it, so it won't fall over or close.

Furthermore, if the relationship Wa×La>Wb×Lb is maintained within the range permitted by the strength of the connecting portion 5 of the second document pressure bonding plate 3b, the difference, that is, Wa×La−Wb
The pressure bonding plate becomes difficult to close by the value of ×Lb, and it is possible to prevent the pressure bonding plate from closing due to the reaction when the pressure bonding plate is opened forcefully.

FIG. 5 is a diagram showing a state in which a thick original such as a book is being copied. As can be seen from this figure, the tip end 11a of the moving member 11 is connected to the first document pressure bonding plate 3.
There is no restriction on the direction in which a is closed, and the first document pressure bonding plate 3a can be bent freely.

As described above, according to this embodiment, it is possible to prevent the original pressure bonding plate from falling down, and in particular, the second document pressure bonding plate 3b
When opened, by regulating the opening angle of the first document pressure bonding plate 3a, the rotational moment around the connecting portion 5 can be set to a small value, and the load on the connecting portion 5 and the members in its vicinity can be reduced. Therefore, it is possible to prevent damage to these members and improve durability without using special reinforcing members or the like. In addition, in recent years, molded plastic parts have been used for body covers, crimp plates, etc. in order to reduce production costs and increase the degree of freedom in design.In terms of strength, it is important to reduce the load applied to these connecting parts. It is also important.

Next, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7.

In this embodiment, the moving member is constructed using a link mechanism. As shown in FIG.
A guide member 21 having a guide shape 22 is provided near the guide shape 22, and the tip end 2 of the moving member 23 is disposed on the surface of the guide shape 22.
3b is brought into contact. Reference numeral 24 denotes a connecting member which is rotatably attached to the second document pressure bonding plate 3b around a rotating shaft 24a, one end of which is attached to the tip 23a of the moving member, and the other end is attached to the pushing member 2.
It is rotatably attached to the end of 5. The tip 25a of the pushing member 25 is connected to the first original pressure bonding plate 3 as in the first embodiment.
It comes into contact with the receiving part 31 of a.

FIG. 7 is a diagram showing the crimp plate in an open state. As shown in the figure, the moving member 23 moves along the guide shape 22 as the second document pressure bonding plate 3b opens, and the movement is transmitted to the pushing member 25 via the connecting member 24.
The opening of the first document pressure bonding plate 3a is regulated by the tip 25a. In the case of this embodiment, there is an advantage that the movement of the moving member 23 due to the guide shape 22 can be amplified by the connecting member 24.

Next, a third embodiment of the present invention will be described with reference to FIGS. 8 and 9.

In this embodiment, as shown in these drawings, a locking portion 33 is provided at one edge of the first document pressure bonding plate 3a, and the locking portion 33 is engaged with the tip portion 34a of the moving member 34. urge By moving the other end 34b of the moving member 34 along the guide shape 22, the moving member 34 and the tip portion 34a
moves and the locking portion 33 abuts against each other, thereby regulating the opening of the first document pressure bonding plate. In this embodiment, these members can be provided inside the pressure bonding plate, which is preferable in terms of appearance.

As described above in each embodiment of the present invention, the opening of the first original pressing plate is controlled by the opening of the second original pressing plate, and the balance of the rotational moment of these members is controlled. By taking this into consideration, it is possible to prevent the original pressure bonding plate from falling.

In addition, the shape of the main body of the copying machine only has a connecting part for the second document pressure plate and a guide shape to prevent the pressure plate from falling, and there is no need for a locking part near the document glass as in the conventional case. It does not become an obstacle when setting an original larger than the original platen glass, and is also preferable in terms of appearance.

Furthermore, since the rotational moment around the opening/closing axis of the crimp plate of the second original can be set to a small value, the load applied to this part is reduced, and it can be constructed from a plastic member that is integrated with the outer cover, eliminating the need for other reinforcing members. This reduces production costs.

[0030]

As explained above, according to the present invention, the opening amount of the first original pressing plate is adjusted around the opening/closing axis of the second original pressing plate in accordance with the opening angle of the second original pressing plate. 1st, 2nd
By providing each member so that the rotational moment due to the center of gravity of the original pressure bonding plate is approximately equal or in the opening direction of the second portion, it is possible to prevent the pressure bonding plate from falling down. Particularly, even when the second original pressure bonding plate is open, it is effective as a stopper.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of a document pressure bonding device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a state in which the original pressing device shown in FIG. 1 is applied to a copying machine.

FIG. 3 is a diagram showing the operating state of the original pressing device according to the first embodiment.

FIG. 4 is a diagram showing the relationship between the rotation moments of the first and second document pressure plates.

FIG. 5 is a diagram showing another operating state of the original pressing device according to the first embodiment.

FIG. 6 is a sectional view showing the configuration of a document pressing device according to a second embodiment.

7 is a diagram showing an operating state of the original pressing device of FIG. 6. FIG.

FIG. 8 is a sectional view showing the configuration of a document pressure bonding device according to a third embodiment.

9 is a diagram showing an operating state of the original pressing device of FIG. 8. FIG.

[Explanation of symbols]

1 Copy machine body 2　Original table glass 3a First original pressure bonding plate 3b Second original pressure bonding plate 4, 5 Connecting part 11, 23, 34 Moving member 31 Receiving part

Claims (2)

[Claims] 1. A document pressure bonding device for pressing a document onto a document table glass, comprising: a first document pressure bonding plate capable of pressing a document placed on the document table glass; a second original pressing plate rotatably connected to the original pressing plate, the other end of which is rotatably attached to the apparatus main body, and capable of pressing the original placed on the original table glass; 1. A document pressure bonding device comprising: rotation control means for regulating the amount of rotation of the first document pressure bonding plate according to the amount of rotation of the second document pressure bonding plate. 2. When the first and second document pressure plates are opened, each of the first and second document pressure plates is rotated around a rotation axis of the second document pressure plate on the apparatus main body side. A claim characterized in that the rotation moments are approximately equal, or the rotation moment of the second document pressure plate is larger than the rotation moment of the first document pressure plate so that the second document pressure plate is in the opening direction. The original pressing device according to item 1.