JPH07120845A - Opening/closing mechanism of original pressing device - Google Patents

Abstract

PURPOSE:To weaken impact at the time of closing a pressing means and to prevent the failure of a device by providing an opening/closing mechanism with a buffer means for applying resistance to the motion in the closing direction of an original pressing means. CONSTITUTION:Compression springs 5, 6 of respective parts constituting the opening/closing device (hinge) 24 of an automatic original feeder are arranged within a hinge frame 1 and receive action by the movement of a slider 8. An oil damper 7 is arranged between the slider 8 and the compression spring 5 and is so positioned that a part thereof intrudes into the compression spring 5. The damper 7 is internally filled with oil 7-C so that the damper slider 7-a moves vertically. The resistance acts on the damper slider 70a when the force is acted thereon in direction C. The resistance is applied to the molten in the closing direction of the pressing member for pressing the original placed on a original tray.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a platen for reading an image of a document in a copying machine or the like, and an automatic document feeder for automatically placing or ejecting the document with respect to the platen.
The present invention relates to an opening / closing device of an automatic document feeder for opening / closing.

Alternatively, the present invention relates to a device for opening and closing a document pressure plate for pressing a document placed on a document mounting table of a document reading device.

[0003]

2. Description of the Related Art Conventionally, in a copying machine equipped with an automatic document feeder, when a document is copied, it is automatically copied by using the automatic document feeder, or the automatic document feeder is used. Instead, the original can be manually placed at a predetermined position and copied.

That is, when the automatic document feeder is used, for example, the automatic document feeder 2 shown in FIG. 10 is used.
When a desired document is placed on the document tray 22 of No. 1 and a start key (not shown) of the copying machine 20 is pressed, the original is automatically placed on the platen glass 23 of the copying machine, which is a portion for reading an image, such as a white belt 25. When the document is conveyed, placed, and stopped at a predetermined position, an optical system (not shown) of the copying machine 20 scans the document, and an image is formed. When the image reading of the original is completed, the white belt 25 ejects the original from the platen glass and reloads it on the original tray 22 again. These series of operations are automatically performed by using the automatic document feeder.

On the other hand, without using the automatic document feeder,
When manually placing the original on the platen glass 23,
1, the automatic document feeder is lifted and opened in a direction away from the platen glass 23, the original is placed at a predetermined position on the platen glass, and the original surface is placed on the platen glass 23.
The document is automatically closed by the automatic document feeder 21 so as to be pressed as closely as possible, and a start key (not shown) of the copying machine 20 is pressed to form an image.

As shown, the automatic document feeder 2
1, an opening / closing device (hinge) 24 for opening and closing is attached, and an opening direction is provided inside the hinge so that the automatic document feeder 21 can be easily opened especially when opening in the lifting direction. A spring for urging the automatic document feeder 21 having a large weight can be smoothly lifted. Further, even when it is closed, due to the action of the spring, the falling speed due to the own weight of the automatic document feeder is suppressed to some extent and the platen glass 23 is gently landed.

[0007]

However, in the above-mentioned conventional example, as is well known, the automatic document feeder automatically feeds the document on the document tray to a predetermined position of the platen,
When the sheet is placed and the copying operation by the copying machine is completed, there are arranged not-shown conveying rollers, ejection rollers, paper guides, drive motors, etc. for performing functions such as ejecting from the platen and reloading on the document tray. Therefore, since it is considerably heavy, the spring for urging the automatic document feeder described above in the lifting direction is also burdened. Especially when it is used for a long time, the ability of the spring is reduced, and the original spring force cannot be produced.When the automatic document feeder is closed, the drop speed increases and the There was a defect that the device was damaged by the impact or the platen glass was damaged.

Further, even if the ability of the spring of the hinge is not deteriorated, even when the user forcibly closes the automatic document feeder, there is a drawback that it may be damaged by the impact at the time of landing.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an opening / closing mechanism for a document pressing device which can reduce the impact of closing the document pressing device and prevent the device from being damaged.

The structure of the present invention for attaining the above object comprises a pressing means which is supported so as to be openable and closable with respect to a document mounting table and which presses a document mounted on the document mounting table, and a closing direction of the pressing means. Buffering means for giving resistance to the movement of
An opening / closing mechanism for a document pressing device characterized by having:

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to an opening / closing device (hinge) of an automatic document feeder, and any known automatic document feeder can be used. That is, as shown in FIG. 10, the automatic document feeder separates document bundles stacked on the document tray 22 one by one, and feeds and conveys them to a platen glass 23 for reading an image on the copying machine body. It can be stopped at a predetermined position according to the size, discharged and transported from the platen, and reloaded on the document tray 22 again. A means for driving a transport path and a transport roller for performing these operations, A control device etc. are built in.

The opening / closing device (hinge) 24 of the automatic document feeder, which is a feature of the present invention, will be described below with reference to the drawings.

FIG. 1 is a drawing which best represents the features of the present invention, and is a perspective view showing each component constituting the opening / closing device (hinge) 24.

Reference numeral 1 is a hinge frame which is also a skeleton of the hinge.

Reference numeral 2 is a backup support shaft for preventing the bent portion 1-e of the hinge frame 1 for fixing the compression coil springs 5 and 6 from being deformed by the spring force.

Numeral 3 is mounted on an elongated hole portion 9-a of the arm 9,
Further, the slider shaft is movable so as to be guided by the elongated hole portion 1-g of the hinge frame 1 and abuts and supports the lower portion of the slider 8.

Reference numeral 4 denotes a hinge shaft which is pivotally mounted in the hole 1-h of the hinge frame 1 and the hole 10-a of the hinge base 10 and which is the center of rotation of the hinge (hinge frame 1).

Reference numerals 5 and 6 are compression springs, which are arranged inside the hinge frame 1 and act on the movement of the slider 8.

Reference numeral 7 is an oil damper, which is a slider 8
And the compression spring 5, and a part thereof is located so as to enter the inside of the compression spring 5.

The slider 8 is guided by the bent portion 1-f of the hinge frame 1 and is movable in the AB direction in the figure, and is supported at its lower portion by the slider shaft 3 under the action of the compression springs 5 and 6.

The arm 9 is rotatable with respect to the hinge base 10 about an arm shaft 11 mounted around the hinge base 10, while
It supports a slider shaft 3 which is mounted on the shaft.

The support column 12 is fixed to the hinge base 10 with screws or the like, and the lower end portion in the figure is inserted into a bush (not shown) of the main body of the copying machine.

The hinge 24 constructed in this way is shown in FIG.
As shown in, the right and left sides of the automatic document feeder are equipped one by one.

The left and right hinges are balanced by using different compression springs inside the hinges depending on the center of gravity of the automatic document feeder, but they have basically the same structure.

FIG. 2 is a side view of the hinge 24 provided in the automatic document feeder 21 when the automatic document feeder is crimped (closed) to the platen glass 23 of the copying machine. The rubber foot 26 provided in the automatic document feeder is brought into contact with the platen glass 23 of the copying machine body 20, and the rubber foot 26 has a positional relationship (height direction) between the copying machine (platen glass 23) and the automatic document feeder. Guaranteed by. A rubber foot (not shown) is also provided on the front side of the automatic document feeder and is in contact with the platen glass.

Since the hinge frame 1 is fixed to the automatic document feeder frame with screws and the like at 1-a and 1-c, the opening / closing center of the automatic document feeder is the hinge shaft 4 which is the center of rotation of the hinge described above. Is opened and closed at the center (FIG. 3 is an open state).

In the state shown in FIG. 2, the slide shaft 3 is at the position where the slider 8 (dotted line) is pushed up in the A direction most,
The compression springs 5 and 6 are in the most compressed state, and are in a state where the spring force is maximized. This spring force is
It is transmitted to the slider shaft 3, the arm 9, and the arm shaft 11, and acts as a moment about the hinge shaft 4. That is,
It acts in the direction of lifting the automatic document feeder in the X direction shown in FIG. Since the moment force in the X direction in FIG. 2 is set to be smaller than the drop force (F in the figure) due to the weight of the automatic document feeder, the state of FIG. 2 can be maintained. The state of FIG. 2 does not naturally change to the state of FIG.

That is, when the state of FIG. 2 is changed to the state of FIG. 3, the user lifts the automatic document feeder, and the moment force in the X direction by the spring is lifted (opened) by the user. The purpose is to lighten the power.

In the state shown in FIG. 3, the slider 8 (dotted line) is at the most moved position in the B direction when the opening / closing angle θ is 55 °, and the slide shaft 3 has the elongated hole portion 1- of the hinge frame 1.
Since it is located up to the end of g, the compression springs 5 and 6 do not act (extend) any further. When the automatic document feeder is opened more than this, the slide shaft 3 can be opened by an amount (up to a position of θ = 90 °) in which the slide hole 3 of the arm 9 can move, but the area is already compressed. Since the springs 5 and 6 are locked, the spring force does not work.

The structure described above is a general hinge structure, and the most characteristic operation of the damper 7 of the present invention will be described in detail below.

FIG. 4 shows the damper 7. The damper 7 is a general oil damper, and is filled with oil 7-c so that the damper slider 7-a can move up and down. Further, when a force is applied to the damper slider 7-a in the C direction, resistance works. Normally, in the initial state, the spring 7-d inside the damper causes the damper slider 7 to move as shown in the figure.
-A is the most protruding. Also, the lower flange portion 7
The compression spring 5 of the hinge is mounted on -b.

FIG. 5A is a diagram when the opening / closing angle θ of the automatic document feeder shown in FIG. 3 is 55 °, and FIG. 5B shows the inside of the hinge at that time.

In this state, as described above, the slider 8
Is the position most moved in the B direction, and the tip of the damper slider 7-a is the bent portion 1- of the hinge frame 1.
It is located away from e.

FIG. 6 (a) is a diagram when the opening / closing angle θ is 15 °, and FIG. 6 (b) shows the inside of the hinge at that time.

In this state, the slider 8 has moved in the A direction since θ = 55 °. The tip of the damper slider 7-a is still distant from the bent portion 1-e.

When the automatic document feeder is closed further (θ <15 °), the weight of the automatic document feeder is larger than the lifting force in the X direction due to the action of the compression springs 5 and 6 described in FIG. Since the drop force G due to is superior to the positional relationship, it naturally closes (θ = 0 °).

On the other hand, when the automatic document feeder is further opened (15 ° ≦ θ <55 °), the drop force G becomes smaller than the lifting force in the X direction, and in addition,
15 ° ≦ θ <55 ° due to friction of the mechanical parts
In the position. Each opening / closing angle can be maintained.

That is, 15 ° <θ <55 ° is the free stop region, and θ = 15 ° is the free stop position.

In FIG. 7, a further closed opening / closing angle θ = 8 °
7-a shows the inside of the hinge at that time.

In this state, when θ = 15 °, the slider 8 moves further in the A direction, and the damper slider 7-
The tip of a is in contact with the bent portion 1-e of the hinge frame 1.

That is, when θ = 8 °, the damper 7 starts to operate, and when θ <8 °, a resistance force opposite to the direction in which the automatic document feeder closes occurs.

For example, when gradually closing the automatic document feeder from the free stop position θ = 15 °, θ = 8
At °, the fall speed decreases and the player lands. In other words, at the moment of landing, it will land quietly.

On the other hand, in the case of opening from θ = 0 °, the damper slider 7-a is only in contact with the bent portion 1-e, so that the resistance force when opening is not generated. That is, the damper 7 operates only when it is closed.

FIG. 8 shows the fall speed of the rubber feet on the front side of the automatic document feeder at each opening / closing angle when the automatic document feeder is naturally closed from the free stop position θ = 15 °. Indicates. The speed is V ₀ <V ₁ <
And _{V 2 <V 3 <V 4} <V 5 <V 6.

In the structure of the present embodiment, the process proceeds in the direction of the arrow indicated by the solid line in the figure, the speed gradually increases from the initial speed V ₀ = 0 at θ = 15 °, and reaches V ₂ at θ = 8 °. But,
As described above, the resistance force due to the damper 7 is generated from θ = 8 °, so the speed drops sharply, and at θ = 0 ° at the time of landing, the speed drops to V ₁ and the vehicle lands.

On the other hand, when the damper is not attached, the vehicle moves in the direction of the dotted arrow in the figure, and the velocity of θ = 8 ° reaches V ₄ from V ₂ at the time of landing.

If the shaded area of speed V ₅ or more reaches the shaded area when landing, the plantain glass of the copying machine with which the front rubber foot of the automatic document feeder abuts will be destroyed. This is a critical speed, and is a speed at which the automatic document feeder itself may be damaged by the impact at the time of landing.

Since the velocity graph shown in FIG. 8 is a case where the velocity is naturally closed from the position of θ = 15 ° as described above,
As shown in the figure, it can be seen that the critical speed is not reached even if the damper 7 is not attached.

However, when the user forcibly closes the automatic document feeder by the intentional force, the speed graph shown in FIG. 9 is obtained.

As in the case of FIG. 8, in the structure of this embodiment, the process advances in the direction of the solid line arrow and closes with a deliberate force, so the speed rises sharply and reaches the critical speed range at θ = 8 °. However, due to the resistance force of the damper 7, when landing at θ = 0 °, the speed is reduced to V ₃ and can be removed from the critical speed range.

On the other hand, when the damper is not attached,
Will reach the V ₆ at the time of landing, there is a possibility that destroy the platen glass or automatic document feeder.

The automatic document feeder is used in a closed state as shown in FIG. 2, and only when the document is manually placed on the platen and copied without using the automatic document feeder.
Open the automatic document feeder. In practice, manual copying is rare and is often used in the almost closed state, that is, the compression springs 5, 6 inside the hinge are often left stressed. Therefore, at worst, the original spring force of the compression springs 5 and 6 cannot be exerted, the lifting force in the X direction described above becomes small, and the drop speed may increase.

Even in such a case, since the damper 7 is attached, it is possible to prevent the platen glass or the automatic document feeder from being destroyed.

Although the above embodiment has been described by taking the example of the copying machine, the present invention can be applied to the document reading apparatus. Further, the invention can be applied not only to the automatic document feeder, but also to a device for opening and closing a document pressure plate that presses a document placed on the document table of the document reading device.

[0055]

As described above, by equipping the opening / closing device of the automatic document feeder with the damper, the drop speed of landing on the platen glass when the automatic document feeder is closed can be suppressed, and the platen glass or the automatic document feeder can be automatically fed. There is an effect that the destruction of the device can be prevented.

[Brief description of drawings]

FIG. 1 is a perspective view showing components of an opening / closing device of an automatic document feeder according to the present invention.

FIG. 2 is a side view when the opening / closing device of the automatic document feeder according to the present invention is closed.

FIG. 3 is a side view when the opening / closing device of the automatic document feeder according to the present invention is opened.

FIG. 4 is a detailed view of the damper of the opening / closing device of the automatic document feeder according to the present invention.

FIG. 5 is a side view when the opening / closing angle of the opening / closing device of the automatic document feeder according to the present invention is 55 °.

FIG. 6 is a side view when the opening / closing angle of the opening / closing device of the automatic document feeder according to the present invention is 15 °.

FIG. 7 is a side view when the opening / closing angle of the opening / closing device of the automatic document feeder according to the present invention is 8 °.

FIG. 8 is a graph showing the falling speed of the automatic document feeder according to the present invention.

FIG. 9 is a graph showing the falling speed of the automatic document feeder according to the present invention.

FIG. 10 is a perspective view showing a copying machine equipped with an automatic document feeder according to the present invention.

FIG. 11 is a perspective view showing the copying machine when the automatic document feeder according to the present invention is opened.

[Explanation of symbols]

 1 Hinge frame 3 Slider shaft 4 Hinge shaft 5, 6 Compression spring 7 Damper 8 Slider 9 Arm 10 Hinge base

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiro Matsuo 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Noriyuki Ueda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canono Within the corporation

Claims (4)

[Claims] 1. A pressing unit that is supported so as to be openable and closable with respect to a document mounting table and presses a document mounted on the document mounting table; and a buffering unit that gives resistance to the movement of the pressing unit in the closing direction. An opening / closing mechanism for a document pressing device, comprising: 2. The opening / closing mechanism of the document pressing device according to claim 1, wherein the buffering means includes a fluid damper. 3. The opening / closing mechanism of the document pressing device according to claim 1, wherein the document pressing unit has a document feeding unit that conveys a document to a document placing table. 4. The opening / closing mechanism of the document pressing apparatus according to claim 1, wherein the buffering means is configured to provide resistance immediately before the pressing means is closed.