JPS6245135B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a wide belt that is provided to cover almost the entire width of the exposure area of a copying machine without any gaps, and the original is fed to the exposure area by a wide belt that covers almost the entire width of the exposure area of a copying machine. Exposure is performed by stopping the document at a predetermined position on the contact glass using a document stopping member that is movable toward and away from the wide belt along the width belt, and then retracting the document stopping member to a position away from the wide belt to stop the document. The present invention relates to a document stopping mechanism for an automatic document feeder of a copying machine, in which a document is ejected from above a contact glass.

There are many automatic copy document feeders that transport the document to the exposure section of a copying machine, automatically stop it at a predetermined position on the contact glass for exposure, and then automatically eject the document from the contact glass. Many products have been commercialized because they can efficiently copy and repeat copying of sheet originals.

The general mechanism of an automatic document feeder will be explained with reference to FIG. 1. The automatic document feeder 2 is attached to the copying machine main body 1 through a shaft 3 and can be opened at an angle of 90 degrees or more to the surface of a contact glass 13 or can be attached and removed. When using normal-sized sheet originals, set the automatic original feeder 2 on the contact glass 13 and use this, and when copying books, large drawings, etc. The original is flipped up and manually placed on the contact glass 13 to make a copy.

The automatic document feeder 2 is wound around a document insertion table 4 that also serves as a lid of a stacker 17, a document conveyance pulley 6 driven by a drive motor 14, a roller 10 and an idle pulley 11 that rotate in synchronization with the document feeder 2. a conveyance section 9 consisting of a conveyor belt 12, and a stacker 1 for storing exposed originals;
It has 7. On the other hand, a stop pawl 15 is provided along the edge of the contact glass 13 of the copying machine body 1 on the document ejection side so as to be movable forward and backward.

When the original 5 is inserted from the original insertion table 4 and detected by the sensor, the drive motor 14 is started and at the same time the pinch roller 7 is pressed against the pulley 6.
The original 5 is guided by the guide plate 8 and sent to the conveying section 9. The document 5 sent to the conveying section 9 is moved to the contact glass 13 by the frictional force between the pulley 6 and the wide endless belt 12 driven at a synchronous speed.
A stop claw 1 is conveyed upward, the tip of which protrudes above the document placement surface, and comes into contact with the outer peripheral surface of the belt 12.
5 and stops. Prior to this, the drive motor 14 stops, and the document is transported to the stop claw 15 by the inertia of the transport member. When the original 5 stops, exposure is performed by the exposure lamp 16, and the stop claw 15 has already been retracted before the exposure is completed, so when the belt 12 is driven, the next original is conveyed onto the contact glass 13 and at the same time. The exposed original is ejected and stored in the stacker 17.

The belt 12 is a wide belt that covers almost the entire width of the exposed area without any gaps so that there is no difference in light reflectance for thin paper originals, and there is no effect on the edges of the belt. When multiple stoppers are used at intervals, it is not possible to stop the document by making the stoppere pass through the belt surface, and the top edge of the stoppere is in contact with the outer edge of the wide belt. The document passage is blocked by the belt and the document passage is retracted from the belt surface to open the document passage and discharge the paper.

Conventionally, this document stopping mechanism has a stop pawl 15 whose upper end is shaped like a comb, which is engaged with the tip of a pawl release arm 19 implanted in a pawl actuating shaft 18 that is pivotally supported on the machine frame. When the document is stopped, the tip of the comb tooth is pressed against the circumferential surface of the belt 12 by the force of the spring, and in response to a release signal, the pivot arm 20 provided on the claw operating shaft 18 in parallel with the claw release arm 19 is activated. There is one in which the tip of the comb teeth of the stop pawl 15 is separated from the belt 12 by pushing down the pawl release pin. In this case, the pressure roller 22 that presses the belt 12 against the contact glass 13 is moved to the stop claw 1.
The belt 12 is arranged on the line between the teeth of the comb of
The teeth of the stop pawl are made to easily come into contact with the circumferential surface of the stop pawl, but in conventionally used stop pawls, the upper end surface of the teeth of the stop pawl is formed into a flat surface.
A rake angle, a relief angle, and a step, which are constituent elements of the present invention to be described later, are not provided. In another conventional device, a comb tooth-shaped stop pawl is provided with a rake angle and a step, and a solenoid is used to slide the stop pawl toward the original contact surface provided with the rake angle. However, the tips of the teeth of the stop pawl are still formed on a flat surface.

The most important part for the stop pawl to accurately stop various documents is the joint between the document conveyance belt and the stop pawl, and if a gap is created in this portion, the document will not be able to be stopped accurately.

As mentioned above, in conventionally used stop pawls, the upper end surface of the comb teeth that contact the belt is a flat surface, so the stop pawl is formed by being pressed by a pressure roller on the line between the comb teeth. If the belt does not conform correctly to the waveform shape of the belt surface, there is a gap in the center of the teeth, and the leading edge of the document curls upward, the document stop operation will not be performed correctly and the document will pass over the stop pawl. There are drawbacks to this.

Also, if a corner of the original gets into the gap, only a part of it will come out of the stopper claw,
Depending on the paper quality, there is a risk of an accident that may damage the manuscript.

The present invention improves the above-mentioned drawbacks of the document stopping mechanism of the conventional automatic document feeder, and provides a document stopping mechanism that can accurately and safely stop documents with poor conditions such as thin paper or curled documents. The purpose is to provide.

Hereinafter, the present invention will be explained in detail based on drawings showing embodiments thereof.

In the document stopping mechanism according to the embodiment of the present invention shown in FIGS. 2 to 4, the upper end of the stop pawl 23 is formed in the shape of a comb tooth, and the upper end of each comb tooth is in contact with the belt 12. 23a has an arc shape with a central portion protruding toward the belt 12 in a direction perpendicular to the paper passing direction. Further, the cross section of each tooth of the stop pawl 23 in the paper passing direction is as shown in FIG.
a and the outer peripheral surface of the belt 12 form a clearance angle α. Further, the surface 23b that the original comes into contact with and the surface perpendicular to the paper passing direction form a rake angle θ. Surface 23a
and the surface 23b form an acute ridge line 23d. Furthermore, at a position slightly below the upper surface of the contact glass 13 at the document stop operation position of the surface 23b in contact with the document, there is a stepped portion 23d whose stepped surface faces upward.
is provided. The direction in which the stop pawl 23 is retracted from the operating position to the non-operating position is substantially aligned with the original contact surface having a rake angle θ, as shown by arrow B in FIG. Further, on the upstream side of the stop pawl 23, as clearly shown in FIGS. 2 and 3, there is a pressure member that presses the back surface of the conveyor belt 12 on the extension of the position between the adjacent teeth of the stop pawl. A pressure roller 22 is provided.

Since this device is configured as described above, the belt 12 with tension is partially pressed against the upper surface of the contact glass 13 by the pressure roller 22. The corrugated shape and the tips of the arcuate teeth formed so that the central part of the stop pawl 23 protrudes are compatible with each other and come into close contact with each other, leaving no gap.

The upper end surface 23a of the teeth of the stop pawl 23 has a clearance angle α with respect to the circumferential surface of the belt 12 in the paper passing direction, so that the belt 12 does not come into surface contact with the surface 23a and is always in contact with the upper end surface 23a and the original contact surface 23b. Ridge line 2 formed
Since the contact is made at 3d, even if the paper curls upward, it will not get between the upper end surface of the stop pawl and the belt and pass through the stop pawl. In addition, since the document abutting surface 23b is provided with a rake angle θ, when the leading edge of the document comes into contact with this surface, the leading edge of the paper slides downward, preventing it from passing above the stop pawl, and ensuring that the document is securely placed. make it stop.

If you use an original whose leading edge is curled downward, the leading edge of the original will slide further downward, and if no measures are taken, it will get between the end of the contact glass 13 and the stop claw 23, resulting in paper ejection failure. However, as shown in detail in FIG.
c is provided, the leading edge of the document will not advance below this, and defective paper ejection is prevented.

In this embodiment, the stop pawl 23 is retracted parallel to the rake angle θ, but within the range of the angle A shown in FIG. Mistakes in releasing the stop are prevented.

As described above, according to the present invention, with a simple configuration,
Even in the case of originals in poor conditions such as thin paper or curled originals, it is possible to stop and release accurately and safely, which is effective in preventing malfunctions and improving copying efficiency.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a conventional copy document automatic feeding device, FIG. 2 is a cross-sectional view of an embodiment of the document stopping mechanism of the present invention as seen in the belt traveling direction, and FIG. 3 is a cross-sectional view showing the belt traveling direction. 4 is a perspective view thereof, and FIG. 5 is an enlarged sectional view illustrating the action of the stop pawl. 1... Copying machine main body, 2... Automatic document feeder, 12
... Belt, 13... Contact glass, 22... Pressure roller, 23... Stop claw (document stopping member), 23
a... Upper end surface of the stop claw, 23b... Original contact surface of the stop claw, 23c... Step portion, 23d... Ridgeline, α... Relief angle, θ... Rake angle.

Claims (1)

[Scope of Claims] 1. The document is conveyed to the exposure area by a wide document conveyance belt member provided so as to cover almost the entire width of the exposure area of the copying machine without any gaps, and the document is conveyed to the exposure area by the document discharge side edge of the contact glass. The document is temporarily stopped at a predetermined position on the contact glass by a document stopping member provided along the side so as to be able to approach and separate from the belt member, and then exposure is performed, and after the exposure is completed, the document stopping member is moved to the belt member. In a document stopping mechanism of an automatic copy document feeder in which the document is ejected from above a contact glass by retracting the document further, the portion of the document stopping member that comes into contact with the conveyor belt is shaped like a comb with a certain pitch. None, a stepped part with the stepped surface facing upward is provided on the surface that contacts the original in a range that is the same as or less than the height of the original placing surface at the original stop operation position, and the original above the stepped part is A rake angle is provided on the surface that contacts the belt, and a relief angle is provided on the surface that contacts the belt so that the document contacts the belt at the ridge line where the document contact surface intersects with the upper end surface, and at the upstream side of the document stopping member. A document stopping mechanism characterized in that a roller for pressing the back surface of the conveyor belt is provided on an extension of the position between each tooth of the member. 2. The retracting direction of the document stopping member from the operating position to the non-operating position is within a range sandwiched between substantially the same direction as the document contacting surface of the member and the document advancing direction. A document stopping mechanism according to claim 1.