JPH0523419B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a document pressing device used in image forming equipment such as copying machines, printing machines, and information recording devices.

Hereinafter, a description will be given using a document pressing device of a copying machine as an example.

In copying machines, a document pressure device is used to fix the document on the document table during copying and to prevent light leakage from the exposure lamp. It is necessary to place it evenly on the mounting surface.

Therefore, as shown in FIG. 1, the conventional document pressure bonding plate 1 is provided with a vertically long arm 4 on a hinge 3 provided for opening and closing with respect to the document placement surface 2.
is loosely inserted into the vertical hole 6 of the copying machine main body 5 so that the hinge 3 can swing up and down, and as shown in FIG. 2 was brought into contact.

However, the original pressure bonding plate 1 of the above-mentioned conventional example has a hinge 3
Since the arm 4 and the arm 4 are integrated, the structure is complicated and the cost is high.

Furthermore, FIG. 2A shows another conventional document pressure bonding plate. This document pressure bonding plate 11 has two hinges, a first hinge 18 and a second hinge 19, instead of moving the hinge 3 upward when copying a thick document as described above, as shown in FIG. 2B. It is possible to copy the thick original 17 in the same way. This document pressure bonding plate 11 has a relatively simple structure compared to the previous example, and allows a thick document 17 to be placed thereon.

By the way, FIG. 2C shows a state in which the document pressure bonding plate 11 is fully opened. In this state, the upper end 11b' of the intermediate portion 11b and the upper end 1
1c' are in contact with each other, and the lock plate 12 on the upper surface of the intermediate part 11b is in contact with the upper end 11a' of the pressing part 11a to prevent clockwise rotation, so that it will not fall any further toward the mounting part 11c. It is retained without doing anything. However, since there is no member to prevent counterclockwise rotation, when the operator fully opens the document pressure plate 11, the counterclockwise rotation occurs due to the reaction, causing the document pressure plate 11 to close. . This is especially inconvenient when a continuous copying operation is performed by converting documents one after another.

Generally, as devices become smaller, lighter, and lower in cost, there is a tendency for the hinge shape of document crimping devices to become much simpler, as shown in Figure 2. As the hinge has become simpler, it has become extremely difficult and complicated to add a device to prevent the document pressing portion from falling.

The present invention has been made in view of the above-mentioned drawbacks of the conventional example, and although it has a very simple structure, even when the document pressing section is forcefully opened, the document pressing section will fall to the closed state due to the reaction. To provide a document pressing device which is inexpensive and has excellent operability, which prevents the problem from occurring.

The configuration of the present invention that achieves the above object includes: a mounting portion for mounting on the main body of an image forming device;
a pressing part rotatably provided with respect to the mounting part; and a document pressing device that presses a document on a document mounting table by opening and closing the pressing part, the mounting part being biased downward. providing a biasing means to
When the pressing section is in the open state or on the way from the open state to the closed state, the pressing section may come into contact with the document mounting table or a member near it, causing the pressing section to inadvertently rotate from the open state to the closed state. A stopper member for locking is provided integrally with the pressing part, so that when a predetermined amount or more is applied to the pressing part in the direction of rotation from the open state to the closed state, the stopper member does not stop the rotation. The document pressing device is characterized in that the mounting portion is configured to be able to be displaced upwardly against the urging force of the urging means.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 3 is a side sectional view for explaining one embodiment of the present invention, in which 22 is a document mounting table;
3 is a mounting portion 3 for attaching the original table 22 to the main body of the copying machine.
This is a document base plate for fixing the document to 0 and attaching the document pressing device 21. The document pressing device 21 is broadly composed of a pressing portion 21a (including a document pressing member 20) for pressing the document and a mounting portion 21b for attaching to the document base plate 23. This figure (FIG. 3) shows a state in which the document pressure bonding device 21 is positioned on the document base plate 23.
The protrusion 2 of the mounting portion 21b is inserted into the hole 23a provided in the hole 23a.
1b' is loosely inserted and positioned, and the mounting part 21b
An elastic member 33 attached to the original base plate 23 engages with the hooking portion 23b of the document base plate 23, thereby biasing it in the direction of arrow A in the figure and holding the mounting portion 21b in a predetermined position.

Further, a mounting portion 21 attached to the original base plate 23
b and the pressing portion 21a are integrally formed by an extremely thin groove portion (hinge portion) 21c, and the pressing portion 21a is configured to be rotatable around the groove portion 21c. Note that in this embodiment, the pressing portion 21a,
The attachment portion 21b, the groove portion 21c, etc. are made of a material such as polypropylene that can be bent without breaking in a thin layer state. In addition, 21d is the pressing part 2
This is a stopper member that is molded integrally with 1a or is attached separately.

Next, the procedure for attaching the original pressure bonding device 21 to the original base plate 23 will be explained based on FIGS. 4A to 4C.
First, the mounting portion 21b of the original pressing device 21 is placed in the position shown in FIG. 4A. Next, the mounting portion 21b is slid in the direction of arrow D. Then, the tip end 33a of the elastic member 33 engages with the lower part of the hooking portion 23b of the original base plate 23, and as it slides further in the direction of arrow D as shown in FIG. 33 in the direction of arrow C. and,
The deformation force acts as a force that urges the attachment portion 21b in the direction of arrow A. As it slides further, the protrusion 21b' climbs over the corner 23c of the document platen 23 as shown in FIG. 4(C) and is loosely inserted into the hole 23a, and is positioned as shown in FIG. Ru.

Therefore, when the operator wishes to attach the original pressing device 21, he only needs to place the original pressing device 21 in a predetermined position and slide it in a predetermined direction as described above. This is very simple and has excellent operability compared to conventional document crimping devices, which are attached with screws or the like and are detached by removing the screws. Further, when removing the original pressing device, the mounting portion 21b can be removed by simply shifting it upward to the position shown in FIG. 4C, and then moving it in the opposite direction of the arrow D.

Next, the operation of the document pressing device when a thick document 7 is placed will be explained based on FIG. Mounting part 2
1b is a projection 21b' and a hole 2 with respect to the original base plate 23.
The elastic member 13 is positioned by engagement with the elastic member 3a.
It is held in place by the biasing force in the A direction so that it does not fall away from the predetermined position. That is, when the thick original 7 is placed on the original platen 22, the attachment part 21b overcomes the biasing force of the elastic member 33 and rotates clockwise around the protrusion 21b', and the groove part 21c rotates clockwise on the original platen 22.
Move upward relative to 3. In this way, the mounting part 2
1b is not fixed to the document table 23, but is positioned elastically by the positioning means 21b and the elastic member 33 that attempts to hold the attachment part in a predetermined position.
The attachment portion 21b is now rotatable, and the groove portion 21c moves upward, making it possible to place the thick original 7 as shown in the figure.

Next, based on FIG. 6, the operation of the document pressing device when the pressing portion 21a is in the open state will be described.
As the pressing portion 21a is opened, the stopper member 21d comes to the position shown by the two-dot chain line in the figure near the opening angle of 90°. In this process, the tip of the stopper member 21d comes into contact with the original base plate 23, and the attachment part 21
b is rotated clockwise around the protrusion 21b' against the biasing force of the elastic body 33 (indicated by the two-dot chain line in the figure). As shown in the figure, this is due to the relationship l<L between the distance l between the groove 21c, which is the center of rotation of the pressing part 21a, and the document platen 23, and the radius L drawn by the stopper member 21d when the pressing part 21a rotates. This is because there is. Therefore, when the pressing part 21a is in the open state as shown by the solid line in the figure, the biasing force in the A direction by the elastic body 33 combines with the weight of the pressing part 21a to work in the direction of lowering the groove part 21c. Groove 21c
The tip of the stopper member 21d located on the left side receives an upward force from the original base plate 23 as a reaction force. That is, in this state, the pressing portion 21a maintains the open state while receiving a clockwise rotational force (indicated by arrow B).

With the above configuration, when the operator fully opens the pressing part 21a in order to place or exchange a copy original, if the operator crosses the position shown by the two-dot chain line in the figure (that is, the stopper member 21d and the original platen When the contact point a with the plate 23 is located on the left side of the groove portion 21c), the pressing portion 21a is rotated in the direction of arrow B in the figure, and the pressing portion 21a is forcefully opened. Even in this case, the inconvenience that the pressing portion 21a falls to the closed state due to the reaction does not occur.

The above is a description of one embodiment of the original pressing device according to the present invention, but it goes without saying that the present invention is not limited thereto.

For example, in the above-mentioned embodiment, the explanation was given of a document pressing device with a hinge structure in which the pressing part and the mounting part are integrally molded through an extremely thin wall, but the application is of course applicable to document pressing devices with other hinge structures. I can do things.

Further, the rotation inhibiting position of the pressing portion is not limited to the vicinity of 90 degrees as shown in FIG. It may also be configured so that it comes in contact with the target and is suppressed.

Further, the stopper member 21d is connected to the original placing table 22.
It may be arranged so that it comes into contact with.

In the original pressing device according to the present invention, the mounting portion is urged downward by the urging means. Therefore, when an attempt is made to forcibly rotate the pressing part from the open state to the closed state while the stopper is blocking the rotation of the pressing part from the open state to the closed state, the mounting part is displaced upward, and
By deforming the biasing means, the biasing force becomes stronger, so the locking force also becomes stronger, and rotation prevention is ensured. Even when you twist and forcefully open the pressing part,
It is reliably prevented from collapsing into the closed state due to the reaction.

Since the document pressing device according to the present invention has the above-described configuration, it has the effect of reliably preventing the pressing portion from collapsing even though the configuration is extremely simplified.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a conventional document pressure bonding plate, FIGS. 2A to 2C are side sectional views of other conventional document pressure bonding plates, and FIG. 3 is a side sectional view of a document pressure bonding plate according to the present invention. 4A to 4C are side sectional views showing the assembly procedure of the pressure bonding plate of FIG. 3, and FIG. 5 is a side sectional view of the document pressure bonding plate according to the present invention on which a thick original is placed. FIG. 6 is an operational explanatory diagram for explaining the mechanism of the present invention. 21... Original pressure bonding device, 21a... Pressing section, 2
1b...Mounting part, 21c...Groove (hinge), 2
1d...Stopper, 22...Document mounting table, 23
...Manuscript base plate, 33...Elastic member.

Claims (1)

[Scope of Claims] 1. Consists of a mounting part for mounting on the main body of the image forming apparatus, and a pressing part rotatably provided with respect to the mounting part, and by opening and closing the pressing part, the document mounting table can be moved. A document pressing device that presses an upper document is provided with a biasing means that biases the mounting portion downward, and the document mounting table is provided with a biasing means that biases the mounting portion downward, and when the pressing portion is in the open state or on the way from the open state to the closed state. or a stopper member that comes into contact with a nearby member and stops the pressing part from inadvertently rotating from the open state to the closed state, is integrally provided on the pressing part, When a predetermined force or more in the direction of rotation is applied to the mounting portion, the mounting portion can be displaced upward against the urging force of the urging means so that the stopper member does not stop the rotation. A document crimping device characterized in that it is configured as follows. 2. The pressing part and the mounting part are connected by a hinge, and the mounting part is provided with a positioning means with respect to the original table, and the hinge is set as the center of rotation of the pressing part. The original pressing device according to scope 1.