JPH06324405A - Original cover for image forming device - Google Patents

Abstract

PURPOSE:To obtain an original cover at a low cost, to attain an easy operability in setting and to prevent a thick original from being floated up by connecting a 1st original cover with a 2nd original cover through a flat elastic member so that the original cover may be foldable. CONSTITUTION:As to the original cover 3, the original cover main body is divided into two parts; the 1st original cover 5 which is loaded on a copying machine main body 1 so that it can be opened/closed through a hinge 4 and the 2nd original cover 6 connected with the 1st original cover 5. And the 1st original cover 5 is connected with the 2nd original cover 6 so that they may be foldable through a leaf spring 7 as the elastic member. The leaf springs 7 are attached to two positions in right and left directions one by one, for example by screwing, etc. Besides, in the case that an adverse effect is given to the image quality because the leaf spring 7 is overlaid on the contact glass 2, it is allowed to install an proper elastic white board on the original pressing surface of the original cover 3. The 1st original cover 5 is connected with the 2nd original cover 6 through the leaf spring 7, so that the original cover 3 having such a constitution is obtained at a low cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document pressure plate of an image forming apparatus such as a copying machine, a facsimile, a printer or the like which holds a document placed on a document placing section.

[0002]

2. Description of the Related Art As a document pressure plate for a conventional copying machine, Japanese Unexamined Utility Model Publication No. 60-46549 discloses a so-called center folding type document pressure plate in which two divided pressure plate bodies are connected via a hinge. ing. The hinge 50 in this case is usually
As shown in FIG. 9, a metal fitting 51 fixed to each divided pressure plate body and a pin 52 connecting the metal fittings 51.
It consists of and. This type of document pressure plate can be operated while pressing the document while preventing displacement of the document by hand when pressing the document, and the document platen is thick even for a thick document such as a book document. There is an advantage that it can be pressed in a shape.

[0003]

However, the hinge 50 used in the above-mentioned conventional center-folding type original pressure plate has a problem that the number of parts is large and the cost is high. Further, when setting a document of a considerably small size, it is difficult to operate the document pressing plate of the center-folded type while manually pressing the document so as not to shift the position. Furthermore, when pressing a document having a large thickness, there is a difference in the magnitude of the pressure contact force between the two pressure plates with respect to the document, and there is a problem that the weaker the contact force between the document and the contact glass is raised.

The present invention solves the above-mentioned conventional problems,
An object of the present invention is to provide a document pressure plate that can be connected at low cost even if the document pressure plate is divided into a plurality of parts, has a simple set operability, and can press a thick document with almost uniform force to prevent the document pressure plate from rising.

[0005]

According to the present invention, in order to achieve the above object, a document pressure plate of an image forming apparatus for holding a document placed on a document placing section can be opened and closed with respect to the image forming apparatus main body. And a second pressure plate foldably connected to the first pressure plate via a plate-like elastic member.

Further, according to the present invention, in order to achieve the above object, the opening / closing fulcrum of the first pressure plate is mounted so as to be movable in the vertical direction when opened / closed with respect to the main body of the image forming apparatus. It is characterized in that an elastic means for constantly pressing down is provided.

Further, in order to achieve the above-mentioned object, the present invention is characterized in that the first pressure plate and the second pressure plate are connected at least at two positions by the plate-shaped elastic member, At least one of them is set to have a spring constant different from that of the other plate-like elastic members.

[0008]

According to the above structure, since the first pressure plate and the second pressure plate are elastically bendably connected to each other via the plate-like elastic member, the cost is lower than the hinge connection.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a plan view of a document pressure plate according to the present invention. In FIG. 1, reference numeral 1 is a main body of an image forming apparatus, for example, a main body of a copying machine, and a contact glass 2 as a document placing table is provided on the upper surface of the copying machine main body 1 as shown by a dotted line. A document pressure plate 3 is provided so as to cover the contact glass 2.

In the original pressure plate 3 of this embodiment, the pressure plate main body is attached to the copying machine main body 1 by a hinge 4 so as to be openable and closable.
And a second pressure plate 6 connected to the first pressure plate 5. The first pressure plate 5 and the second pressure plate 6 are foldably connected by a plate spring 7 as a plate-like elastic member as shown in FIG. As the leaf spring 7, for example, a stainless plate or the like is suitable. Leaf spring 7
As shown in FIG. 1, they are attached to the right and left at a total of two places, for example, by screwing. When the leaf spring 7 overlaps the contact glass 2 and adversely affects the image quality, the leaf spring 7 may be covered with an appropriate white plate that expands and contracts on the document pressing surface of the document pressure plate 3. The leaf spring 7 may be attached at a position where it does not overlap the contact glass 2 without providing the white plate.

The original pressure plate 3 having the above-mentioned structure is provided with a first plate spring 7 for the first plate.
Since the pressure plate 5 and the second pressure plate 6 are connected, the cost is low.
Further, for example, when a thick original O such as a book original is copied, as shown in FIG. 3, the handle portion 8 on the front end side of the original pressure plate 3 is pressed downward by a hand to generate a reaction force of the leaf spring 7. A downward force for pressing the original O is also applied to the first pressure plate 5, and the pressability of the book original O is improved. Furthermore,
If the dividing position of the first pressure plate 5 and the second pressure plate 6 is aligned with the center of the document placement reference of the contact glass 2, a pressing force is applied to the center of the book document O and the lifting of the central portion of the book document is suppressed. To be

The first pressure plate 5 and the second pressure plate 6 described above are shown in FIG.
As shown in FIG. 5, it is preferable that the side surfaces 5a, 6a facing each other in the connecting portion are formed into inclined surfaces that are separated from each other in the upward direction. That is, it is preferable that the side surfaces 5a and 6a are formed so as to form a V-shaped groove. According to this structure, the opening angle of the second pressure plate 6 with respect to the first pressure plate 5 is restricted to the position where the side surfaces 5a, 6a contact each other, and the leaf spring 7 can be used within its elastic deformation region. Therefore, the plastic deformation of the leaf spring 7 can also be prevented.

FIG. 5 is an explanatory view of a manuscript pressure plate according to another embodiment of the present invention. In this embodiment, the mounting portion of the copying machine main body 1 and the first pressure plate 5 is attached to the first pressure plate 5. A pin 9 serving as an opening / closing fulcrum is provided, and the pin 9 is an elongated hole 11 formed in a guide portion 10 provided in the copying machine main body 1 via a bearing or the like.
Is movably fitted to. The elongated hole 11 extends in the vertical direction so that the entire document pressure plate 3 is movable in the vertical direction. A spring 12 as an elastic means that constantly applies a downward pulling force to the bearing portion of the pin 9 is locked to the document pressure plate 3. Due to the pulling force of the spring 12, the document pressing plate 3 is normally held at the position where the pin 9 is at the lowest position of the elongated hole 11.
The strength of the spring 12 is set to be stronger than that of the leaf spring 7.

As shown in the figure, when the thick original O is pressed, the original pressure plate 3 having such a structure presses the handle portion 8 on the leading end side downward, so that the first pressure plate 5 uses the contact edge of the original O as a fulcrum. The pin 9 side moves upward by the reaction force of the leaf spring 7, and the document pressure plate 3 presses the document O. Therefore, the first pressure plate 5 and the second pressure plate 6 are thick
It can be pressed with almost even force against. Therefore, the contact force between the original O and the contact glass 2 in the left-right direction in FIG. 5 becomes substantially equal, and the problem that the original O is lifted up on one side and the image quality is deteriorated can be surely prevented.

By the way, the manuscript pressure plate 3 in which the pressure plate body is divided
Is easier to press when pressing the original than a rigid one-plate pressure plate. That is, when the original O is pressed by the divided original pressure plates 3, the second pressure plate 6 can be closed while pressing the original O by the first pressure plate 5. However, when the original O has a small size or is placed in a special position, the first pressure plate 5
Therefore, it may be difficult to close the second pressure plate 6 while pressing the document O.

Therefore, as shown in FIG. 6, the original pressure plate 3 is
Dividing the first pressure plate 5 and the second pressure plate 6 on a substantially diagonal line can reduce the risk of shifting even a small-sized original O or the like. Further, in such a configuration, as shown in FIG. 7, even with the original O placed on the first pressure plate 5 side, there is an advantage that the second pressure plate 6 can be closed after pressing the first pressure plate 5 original O. .

Further, by changing the spring constants of the left and right leaf springs 7, the pressability of the small-sized original O is improved. That is, when the spring constants of the left and right leaf springs 7 are different, as shown in FIG. 8, the second pressure plate 6 can be tilted in the left-right direction to be closed, and the operator can hold the original O just before closing the second pressure plate 6. It is held down. Therefore, the risk of causing the document O to be displaced is reduced.

[0018]

According to the first aspect of the invention, since the first pressure plate and the second pressure plate are foldably connected via the plate-like elastic member, the cost is lower than that of the hinge connection.

According to the structure of claim 2, when a thick original is pressed, the pin side of the first pressure plate is moved upward by the reaction force of the leaf spring with the contact edge of the original as a fulcrum. Therefore, it is possible to prevent the first pressure plate and the second pressure plate from being pressed against a thick original document with a substantially uniform force, so that one side of the original document is not lifted.

According to the third aspect of the present invention, the second pressure plate can be tilted and closed with respect to the left-right direction, and the operator can press the document just before closing the second pressure plate. The risk of occurring can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view of a document pressure plate according to the present invention.

FIG. 2 is an enlarged perspective view of the leaf spring.

FIG. 3 is an explanatory diagram when a book document is pressed by a document pressure plate according to the present invention.

FIG. 4 is an enlarged explanatory view of a connecting portion between a first pressure plate and a second pressure plate.

FIG. 5 is an explanatory view showing another embodiment of a document pressure plate according to the present invention.

FIG. 6 is an explanatory plan view showing a modified example of a document pressure plate.

FIG. 7 is a perspective view at the time of use thereof.

FIG. 8 is a perspective view of another embodiment of the present invention in use.

FIG. 9 is an exploded perspective view of a hinge used in a conventional document pressure plate.

[Explanation of symbols]

 1 Copy machine main body 2 Contact glass 3 Original pressure plate 4 Hinge 5 First pressure plate 6 Second pressure plate 7 Leaf spring 9 Pin 12 Spring O Original

Claims (3)

[Claims] 1. A manuscript pressure plate of an image forming apparatus for pressing a manuscript placed on a manuscript placing portion, wherein a first pressure plate is attached to the main body of the image forming device so as to be openable and closable, and a plate-shaped plate is formed on the first pressure plate. A document pressure plate, comprising a second pressure plate foldably connected via an elastic member. 2. The original pressure plate of the image forming apparatus according to claim 1, wherein an opening / closing fulcrum of the first pressure plate is mounted so as to be vertically movable when opened / closed with respect to the image forming apparatus main body. An original pressing plate characterized by being provided with elastic means for constantly pressing the opening / closing fulcrum downward. 3. The document pressure plate of the image forming apparatus according to claim 1, wherein the first pressure plate and the second pressure plate are connected at least at two positions by the plate elastic member, and the plate elastic member is provided. At least one of the plate-shaped elastic members is set to have a spring constant different from that of the other plate-shaped elastic members.