JPH058889A - Document conveying device - Google Patents

Abstract

PURPOSE:To prevent breakage of a device even when an excessive load is exerted, in a document conveying device which has a flange part to prevent the deviation of a conveyance belt and determines a vertical position relation between a device body and a platen glass by means of a spacer. CONSTITUTION:A relative distance between a flange member 30 and a platen glass 15 is increased to a value higher than a maximum resilient deformation amount of resilient substance legs 29 and 28 formed of a resilient member. Even when a leg is compressed due to an excessive load, the flange member 30 is prevented from being contact with the platen glass.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeder, and more specifically, it is attached to, for example, an image forming apparatus, and feeds an image forming original (sheet original) to a reading position of the image forming apparatus and discharges it. The present invention relates to the configuration of a document transporting device that performs the operation.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 7, a document feeder has a loading means 1 for loading documents, separating means 6-9 for separating the documents, and a transporting means for transporting the separated documents to a reading position. It is composed of 11, 12, and 18.

Of these, the conveying means is various roller pairs 11,
12 and a wide conveyance belt 18 arranged to face the reading position in many cases. That is, in FIG. 7, an endless conveyor belt 18 is suspended between the belt driving roller 16 and the turn roller 17, and pressure is applied by a plurality of pressing rollers 19 from the opposite side of the conveyor belt 18 from the original facing surface.
By driving the conveyor belt 18, the platen 1
It is possible to convey the document onto the sheet 5, or to stop the sheet at a predetermined position such as the reading position and to discharge it from the platen 15.

[0004]

However, in order to convey an original with the above-mentioned endless belt, the circumference of the belt must be twice the maximum original size (conveying direction), and the width direction must be adjusted to the maximum size. Since the belt becomes long, the belt is likely to meander and deviate, which may affect the accuracy of stopping the document at the reading position.

Therefore, there is an apparatus in which the deviation preventing means is provided by providing flange members near both ends of the drive roller and the turn roller.

On the other hand, in order to stabilize the conveyance of the original document on the platen and prevent the image defect due to the floating of the original document, it is advantageous to bring the driving roller and the turn roller of the belt as close to the platen as possible. .. The outer circumferences of the drive roller and turn roller are slightly raised so that they do not contact the platen, and the belt is pressed against the platen by the pressing roller on the back of the conveyor belt. The conveyor belt floats slightly above the platen up to the rollers. In order to suppress the flying distance to a smaller extent, it is necessary to bring the drive roller and the turn roller closer to the platen as described above.

However, when relying on the flange member as the belt deviation prevention member, the diameter of the flange member is naturally larger than the diameters of the driving roller and the turn roller, so that the driving roller and the turn roller are prevented from coming into contact with the platen. It is necessary to separate the platen from the platen to some extent.

In order to satisfy such contradictory conditions, it is necessary to ensure the distance between the driving roller, the turn roller and the flange member and the platen glass to a minimum and with high accuracy. For that purpose, it is a simple method to provide a spacer for ensuring the space. Moreover, for the purpose of assurance, it is preferable to provide the spacer at a position where the relative displacement with the drive roller, the turn roller and the flange member is small and to ground the spacer to the upper surface of the platen glass.

However, if the spacer is made of a rigid body, an impact force will be applied to the platen glass at the time of opening / closing operation of the device, and there is a danger of damage. Therefore, in the prior art, the spacer is made of an elastic member that absorbs the impact force. Seen. However, in the case of an elastic member, there is a drawback that elastic deformation is caused by an operational overload such as the above-mentioned opening / closing operation, an impact force, and an unpredictable excessive force in physical distribution, and the interval is not guaranteed instantaneously. .. In addition, there is a drawback that packing costs and logistics costs are increased to prevent these problems.

[0010]

According to the present invention, the relative position between the original conveying apparatus and the platen glass of the image forming apparatus is regulated by the elastic member, and the conveying is arranged so as to face the platen glass. The relative distance (L ₁ ) between the platen glass and the flange member provided to prevent the belt from shifting is determined by the maximum elastic deformation amount (H ₁ −H ₂ ) of the elastic member.
By making it larger than that, it is possible to position the conveyor belt as close as possible to the reading position and to position it at a position where interference does not occur even if an overload or impact force is applied, making it possible to stabilize the original conveyance characteristics and images and improve physical distribution. Accidents such as damage can be prevented without increasing the cost. (The reference signs are for reference only, and are not limited thereto.)

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a circulation type document feeder according to an embodiment of the present invention. To briefly describe the configuration, reference numeral 1 denotes a document tray on which the operator places the document S. Reference numeral 2 is a document stopper, and the leading edge of the document is abutted. A half-moon roller 3 separates the leading edge of the document and conveys the bottom sheet of the document. Numeral 4 is a weight to drop the document when it is difficult to enter the separating portion and pressurize it from above the half-moon roller 3 to assist the document transportation.
Denoted at 5 is a separation regulation plate which prevents the bundle of documents from being pushed in.
A paper feed roller 6 cooperates with a pair of separation rollers 7 and 8 and a separation belt 9 described below to separate the lowermost document from the document stack.
The tip of the upper guide 10 guides the document so that the document easily enters the registration nip formed by the registration roller 11 and the reversing roller 12. 13 is an inner guide plate, 1
Reference numeral 4 denotes a middle guide, each of which forms a transport path for the document and guides the document onto the platen 15. Conveyor belt 1 stretched between drive roller 16 (broken line portion) turn roller 17 (broken line portion)
The document is conveyed onto the platen 15 by the roller 8 and the roller 19 which is pressed from its back surface, and stops. After the copying is completed, the conveyor belt 18 is reversed and the original is scooped up by the jump table 20 and passes through the path formed by the lower guide 21 and the middle guide 14, and further between the open / close guide 22 and the reversing roller 12 and the upper part of the flapper 23. , And is reloaded on the tray 1 by the discharge roller pair 24 through the upper portion of the upper guide 10. Each of the rollers 19 is independently pressed against the platen by a spring to bring the belt into close contact with the platen.

During both sides, the flapper 23 is deflected so that the original document passes under the flapper and is conveyed again onto the platen by the registration roller 11 and the reversing roller 12.

Next, the periphery of the conveyor belt 18 will be further described. 1 and 2, the pressure roller 19 on the back side of the belt
Are supported by stays 25, 26 and 27, respectively, and the stays 25 and 27 have rubber legs 28 and 29, respectively.
Are attached to the front side of the conveyor belt 18 outside the region. The rubber legs (elastic body legs) 28 and 29 are grounded on the platen 15, and the vertical relative positions of the entire document feeder and the platen 15 are determined. The belt flange 30 is disposed near both ends of the shaft 16a of the drive roller 16 and the shaft 17a of the turn roller 17 so as to sandwich the conveyor belt 18 from both sides (roller diameter + conveyor belt thickness × 2).
It has a diameter of + α and prevents the conveyor belt 18 from meandering and shifting. The stay and the shafts 16a and 17a are provided in the main body B ₀ of the document feeder.

FIG. 3 is a top view of the periphery of the conveyor belt 18. The turn roller 17 is axially supported by the slide plates 31 and 32 on the front side and the back side, respectively, and is urged rightward in the drawing by springs 33 and 34 to give proper tension to the conveyor belt 18. Therefore, by removing the springs 33 and 34, the turn roller 17 can be slid together with the slide plates 31 and 32 in the left direction in the figure, that is, in the direction in which the tension of the conveyor belt 18 is relaxed. Then, the conveyor belt 18 is pulled out in the front direction (downward in FIG. 3), so that the conveyor belt 18 can be easily replaced.

Next, the mounting state of the sheet material conveying device and the image forming apparatus will be described. FIG. 4 is a view of both of the above devices viewed from the side. The document feeder B ₀ has a leg member 35.
Is attached to the side of the image forming apparatus, and the tip end of the bolt 36 attached to the tip of the leg member is abutted against the pedestal portion 37 of the image forming apparatus for positioning. Further, the bolt 36 and nut 38 at the tip of the leg member 35 are vertically adjustable. The document feeder B ₀ can be opened and closed about the rotation center 39 as shown by the arrow in the figure. In the closed state, the rubber legs 28, 29 attached to the tip end
Are positioned by grounding on the platen 15 of the image forming apparatus.

The bolt 36 described above is arranged so that the apparatus and the platen 15 are substantially parallel to each other when the original conveying apparatus is closed.
Adjust.

Next, the characteristic part of the present invention will be described.

FIGS. 5 and 6 show the positional relationship among the conveyor belt 18, the flange member 30, the rubber leg 28 and the platen 15 from the side direction. FIG. 5 shows a normal original conveying apparatus closed state, and FIG. 6 shows an arrow. FIG. 7 is an operation state diagram when an overload or a shocking force is applied in the direction.

In FIG. 5, the height H ₁ of the rubber leg guarantees the distance between the document conveying device and the platen 15, and in this state, the distance L ₁ between the flange member 30 and the platen 15 is the conveyance belt 18 and the platen 15. The distance is set so that there is no problem even if the flange 30 rotates.

In FIG. 6, the height H ₂ of the rubber leg is elastically deformed by Δh = H ₁ −H _{2 with} respect to the height H ₁ described above. The distance L ₂ = L ₁ -Δh from the platen 15 is L ₂ => 0, which is kept slightly. It is considered that the belt and the flange do not rotate in the state of FIG. 6, and L ₂ may be smaller than the distance L ₁ described above.

[0021]

As described above, in order to prevent the deviation of the conveyor belt arranged opposite to the platen glass, the relative position between the original conveying apparatus and the platen glass of the image forming apparatus is regulated by the elastic member. By making the relative distance between the provided flange member and the platen glass larger than the maximum elastic deformation amount of the elastic member, there is no risk of damage such as sudden load above normal load or abnormal load. Can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a document feeder according to the present invention,

FIG. 2 is a detailed view of the area around the conveyor belt,

FIG. 3 is a top view of the area around the conveyor belt,

FIG. 4 is a view showing a state in which a document feeder and an image forming apparatus are attached,

FIG. 5 is a state diagram of positioning of the document feeder and the image forming apparatus,

FIG. 6 is an operation state diagram of a positioning portion between the document feeder and the image forming apparatus,

FIG. 7 is a front view of a conventional example.

[Explanation of symbols]

 15 Platen 18 Conveyor Belt 28, 29 Rubber Leg (Elastic Member) 30 Flange

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazuhiro Aoki 5540-11 Sakate-cho, Mizukaido-shi, Ibaraki Canon Aptex Corp.

Claims (1)

Claim: What is claimed is: 1. An image forming apparatus, which is attached to an image forming apparatus and conveys an original to a reading position on a platen glass of the image forming apparatus. The relative distance between the platen glass and the flange member that is regulated by the elastic member and that is provided to prevent the deviation of the conveyor belt that is arranged opposite to the platen glass is greater than the maximum elastic deformation amount of the elastic member. A document feeder that is large in size.