JPH0471816B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an automatic document feeder used in a copying machine, and more particularly to an automatic document feeder used in a case where the automatic document feeder is placed over a document table so that it can be opened and closed like a cover.

Conventional Technology In a typical electrophotographic copying machine, an original is placed on a transparent platen glass provided on the top of the device, and an electrostatic latent image is deposited on a photoreceptor by scanning exposure from the bottom of the platen glass. An image is formed, developed with a developer, made visible, and then transferred and fixed onto copy paper to obtain a copy. During scanning exposure, light emitted from a high-intensity lamp such as a halogen lamp scans the entire surface of the platen glass, so a document cover is usually provided on the top of the copying machine to prevent this light from leaking outside the copying machine. , the operator protects his eyes from high-intensity light by placing a document cover over the document placed on the platen glass.

When copying using a copier with the above configuration, if there is only one original, there is no problem since you only need to cover the cover once even if there are many copies, but when there are many originals, there is no problem. This requires the operation of covering each document one by one, which poses a problem in that copying efficiency deteriorates.

Recently, in view of this problem, models have been provided that are equipped with an automatic document feeder that eliminates the need to open and close the cover each time when copying various types of documents. This is installed on the platen glass so that it can be opened and closed, and drives an endless belt stretched between a pair of belt drive rollers in the center of the belt to transport the original to the optimum position on the platen glass and finish copying. This is to eject the original that has been read.

Problems to be Solved by the Invention The document feeding device described above is normally configured to be able to be opened and closed by a hinge provided on the top surface of the copying machine opposite to the working side, and is shaped like a cover. However, the shape is not necessarily symmetrical, and some of the heavier components may be biased to either side, and the center of gravity may be significantly far from the center. many.

FIGS. 3a and 3b are shown to explain the above-mentioned case, which includes a pair of belt-driven rollers 10 and a belt 12 stretched between them, and guides the copied original in a desired direction. A document feeder 16 having a paper conveyance means 14 for ejecting the paper is provided on the upper surface 18 of the copying machine so as to be openable and closable via a hinge 20 provided on the opposite side of the surface. When a document feed operation is required, the document feeder 16 is moved so that there is no gap between the platen glass 22 provided on the top surface 18 of the copying machine and the belt 12, as shown in FIG. 3b.
By placing the original and inserting the original in the direction of arrow A in the figure, the original is transported to a preset optimal position above the platen glass 22, and after making the desired number of copies, the original is transferred to the paper transport means 14. The document is discharged onto the upper surface of the document feeder 16 by conveyance rollers 24 and 26 provided inside the document feeder 16 . Further, when the document feeding operation is not required, the document feeding device 16 can be operated without operating the belt drive control means (not shown).
can be used simply as a cover.

In such a document feeding device 16, the weight of the portion a consisting of the paper conveying means 14 is generally as follows.
b consisting of belt 12, belt drive roller 10, etc.
It is heavier than the rest. Therefore, the center of gravity of the document feeding device 16 in the document advancing direction is significantly separated from the approximate center of the device, as shown by arrow B in FIG. 3b, for example. However, the hinge 20 that fixes the document feeder 16 to the copying machine body is usually not installed symmetrically with respect to the center of gravity due to the strength suitability of the device, and the deviation of the center of gravity from the center of the hinge In a model with a particularly large size, the upstream side of the document feeder 16 in the document advancing direction sometimes floats slightly above the platen glass 22. In such a case, since there was no means to correct the above-mentioned floating deformation in the conventional document feeder, the platen glass 2 was moved by the belt.
There have been problems in that the originals conveyed onto the printer 2 may be deviated from the proper position, or the originals may not be conveyed at all.

The present invention has been made in view of the above-mentioned problems, and its purpose is to make it difficult for the upstream side in the document feeding direction to float even if the weight member is disposed biased to either the left or right side, and even if it does float, it is easy to float. An object of the present invention is to provide a document feeding device capable of correcting the deformation.

Means for Solving the Problems The automatic document feeder of the present invention has a frame that is provided to be openable and closable with respect to the platen glass of a copying machine, and whose rotational axes are parallel to each other and approximately parallel to the top surface of the frame. a pair of belt drive rollers supported by the frame, and an endless belt stretched between the pair of belt drive rollers, and with the frame closed relative to the platen glass, the pair of belt drive rollers In an automatic document feeder configured to transport a document between the endless belt and the platen glass by driving a The elastic member is fixed near one end, and the other end of the elastic member is connected to the other end of the upper surface of the frame on the upstream and downstream sides in the document conveyance direction through a positioning member that regulates the height from the upper surface of the frame. It is characterized by being fixed near the end.

In a preferred embodiment of the present invention, the elastic member fixed to the upper surface of the frame is made of common structural hard steel. Further, the positioning member provided at one end of the elastic member that is not fixed to the frame is desirably made of a screw member or the like that is screwed onto the frame and whose height can be freely changed.

Function In the document feeding device of the present invention, an elastic member is disposed across the document feeding direction, one end of which is fixed to the heavy component side of the upper surface of the frame, and a positioning member is provided between the other end and the frame. Therefore, the elastic force of the elastic body member acts on the frame in a direction opposite to the direction in which the frame tries to float.

Embodiments Preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 1a and 1b are a plan view and a partially sectional side view of the document feeder of the present invention, in which a frame 28 of the document feeder is provided on the top surface 18 of the copying machine via hinges 20 and 20 so as to be freely openable and closable. ing. A biasing member (not shown) that biases the document feeder 16 in the opening direction is installed inside the hinge 20 to reduce the apparent operating weight of the document feeder. Reference numeral 10 denotes a pair of belt driving rollers that are rotatably supported around a shaft (not shown) provided on the frame 28, and are rotationally driven by a rotation driving means (not shown), and the belt is wound between the pair of rollers. 12. The belt 12, which serves as the background during copying, is seamlessly formed from white rubber or the like, and a protruding pad 121 is formed on the front side of the belt so as to easily catch the leading edge of the document.

Reference numeral 30 denotes a feed roller provided on the frame 28 to capture and convey a manually inserted document, and the document captured by the feed roller 30 is
The sheet is conveyed until the leading edge of the sheet comes into contact with the locking claw 32 and is once locked. The locking claw 32 is attached to the document feeder 16
2 across the bottom surface of the belt drive roller in the rotational axis direction.
They are arranged to be movable up and down, and are configured to be hidden inside the document feeding device after locking the document conveyed by the feeding roller 30 and correcting its inclination. 34 is the top surface 18 of the copying machine
This is a registration gate that is rotatably provided around a rotation shaft 341 provided on the platen glass 2.
The device is configured so that the document is once locked so that it is held in an appropriate position on the copying machine 2, and then it is hidden inside the copying machine after the desired number of copies have been made. After copying, the original is transferred to a pair of paper guides 36 by a pair of transport rollers 24 and 26 that are rotationally driven inside the paper transport means.
The document is conveyed between the document feeders and is discharged onto the top surface of a cover (not shown) of the document feeder.

The frame 28 of the document feeder is made of a metal material or the like so as not to be easily deformed, and an elastic member 3 made of general structural hard steel is mounted on the upper surface of the frame 28.
Two 8's are placed. One end 381 of the U-shaped elastic member 38 is fixed to the side end on the paper transport means 14 side of the upper surface of the document feeder by a fixing means 39 such as a screw, and the other end 382 is attached to the frame 28. A set screw 40, which serves as a positioning member, is attached to a female thread formed in a direction substantially perpendicular to the top surface.
is screwed on. Furthermore, the attachment members 42a and 42b are attached to the upper surface of the frame 28 via the long portion 383 of the elastic member 38 so that the long portion 383 of the elastic member 38 does not float above the frame 28.

Next, the adjustment of the set screw 40 for positioning the elastic member 38 in the document feeder of the present invention and its actual operation will be explained.

As mentioned above, the set screw 40 is provided on the top surface of the document feeder on the side opposite to the heavy parts, and when the center of gravity is relatively shifted to the left as in this example, the set screw 40 is By tightening, one end 382 of the elastic member is lifted, and the set screw presses the frame 28 due to its elastic force. In this case, due to the pressing force, a torsional stress is elastically applied to the long portion 383 of the elastic member, and one end 381 fixed to the upper surface of the frame 28 is subjected to a reaction force to lift the document feeder upward. Force acts. As a result, the frame 28 is slightly bent in the document feeding direction, and the rotation axis of the belt drive roller 10 located on the upstream side in the direction is lowered relative to the rotation axis 10 on the downstream side, so that the center of gravity of the frame 28 is slightly bent. This eliminates lifting of one side of the document feeder due to misalignment.

Here, when one end 382 of the elastic member 38 is lifted from the upper surface of the frame 28, not only the long portion 383 of the frame is subjected to torsional stress, but also the portion corresponding to the attachment member 42a is subjected to upward stress. A downward force acts on a portion of the mounting member 42b that corresponds to the mounting member 42b. As a result, the mounting members 42a and 42b on the top surface of the frame 28
The above-mentioned force also acts in the same direction at the corresponding position via them. Thus, although the one end 381 of the elastic member 38 and the attachment member 42a and the set screw 40 and the attachment member 42b each exert a pressing force or a tensile force in the opposite direction, that is, in the direction of twisting the frame 28, the main force is In the document feeder of the invention, two U-shaped elastic members 38 are arranged so that their long members are parallel to each other, so that the forces trying to twist the frame 28 conflict with each other. Therefore, the frame 28 deforms only in the direction of moving up and down relative to the rotation axis of the belt drive roller 10, which is the original purpose.

Therefore, by setting the degree of tightening of the set screw 40 according to the amount of floating of the document feeder due to the deviation of the center of gravity, it is possible to set an appropriate distance between the belt 12 and the platen glass 22. .

FIG. 2 shows another preferred embodiment of the present invention, in which the elastic member provided on the frame of the document feeder main body of the first embodiment is not U-shaped but a simple plate. It is assumed that That is,
In FIG. 2, one end of a plate member 38' made of general structural hard steel is fixed to the heavier side of the frame 28 by fixing means 39' such as screws, and the other end is fixed to the heavier side of the frame 28.
A set screw 40' is threaded in the same manner as in the embodiment. In this embodiment, the elastic force of the plate member 38' is only a pressing force and a reaction force to the frame 2.
8, there is no need to consider the torsion of the frame, and any number of plate members 38' may be used as long as they are provided at equal intervals in the depth direction of the frame.

In the document feeder of the present invention, mainly for the purpose of correcting the frame when the center of gravity is biased,
Although an elastic member and a set screw are provided as positioning members, according to the above-mentioned working structure, even for the purpose of fine vertical adjustment of the belt especially when the center of gravity of the document feeder is not biased, Of course, the present invention can be used.

In addition, in the present invention, since the elastic strain stress of the elastic member is applied to the frame to correct it, if the shape of the elastic member is the same, a material with a large elastic modulus is used to correct the elastic member. The frame can be corrected more effectively with this configuration.

Effects of the Invention In the document feeding device of the present invention, an elastic member is arranged across the document feeding direction, one end of which is fixed to the weight member side of the upper surface of the frame, and a positioning member is provided between the other end and the frame. With this arrangement, even if one side of the document feeder is lifted up due to a heavy component, it is possible to easily correct the frame and return it to a normal state.

Therefore, it is possible to freely set the position of the hinge for attaching the document feeder to the copying machine body, regardless of the position of the center of gravity of the document feeder.

[Brief explanation of drawings]

1a and 1b are a plan view and a partially sectional side view of a document feeder showing a preferred embodiment of the present invention;
Figures a and b are a plan view and partially sectional side view of a document feeder showing another preferred embodiment of the present invention, and Figures 3a and b are document feeders shown to explain the problems of the prior art. FIG. 2 is a plan view and a partially cross-sectional schematic side view of FIG. 10: Belt drive roller, 12: Belt, 1
4: Paper conveying means, 16: Document feeding device, 20:
Hinge, 22: platen glass, 24, 26: conveyance roller, 28: frame, 30: feed roller,
32: Locking claw, 34: Registration gate, 38: Elastic member, 38': Plate member, 39,
39': fixing means, 40, 40': set screw, 42a, 42b: attachment member.

Claims (1)

[Scope of Claims] 1. A frame provided to be openable and closable relative to the platen glass of a copying machine, and a belt supported by the frame so that its rotation axes are parallel to each other and substantially parallel to the top surface of the frame. a pair of drive rollers; and an endless belt stretched between the pair of belt drive rollers, and by driving the pair of belt drive rollers with the frame closed relative to the platen glass, the endless belt and the In an automatic document feeder configured to transport a document between platen glasses, one end of an elastic member is fixed near one end of the upper surface of the frame on either the upstream side or the downstream side in the document conveyance direction, and The other end of the elastic member is fixed near the other end of the upper surface of the frame on the upstream and downstream sides in the document conveyance direction via a positioning member that regulates the height from the upper surface of the frame. automatic document feeder.