JP2687232B2 - Sheet feeder - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device provided in a computer, a copying machine, a facsimile, a word processor, a typewriter, and other various machines having a mechanism for feeding sheets. is there.

(Background of the Invention) Conventionally, an apparatus of this type is configured to form a traveling wave in an elastic body that holds a sheet and send the sheet, as disclosed in Japanese Patent Laid-Open No. 59-177243. It was

Here, the principle of sheet conveyance in the above proposal will be described with reference to FIG.

The sheet 13 is held by the elastic members 11 and 12 with an appropriate pressing force. Progressive bending vibrations (traveling waves) are formed in the elastic bodies 11 and 12, and the phase difference between these traveling waves is spatially 180 °. The bending vibrations of 12 and 12 proceed so that the respective convex portions are always opposed to the sheet 13 side. At this time, when attention is paid to a material point having, for example, a convex portion on the surfaces of the elastic bodies 11 and 12, the material point generally moves in an elliptical orbit. Second
In the figure, as for the elastic body 11, when the traveling wave travels rightward, the mass point draws a clockwise elliptical locus as shown in the figure. Therefore, the direction of movement of the mass point of the convex portion is opposite to the direction in which the vibrations of the elastic bodies 11 and 12 proceed, and this acts as a force for transporting the sheet 13.

On the other hand, in the concave portion, a sheet transfer force in the same direction as the traveling direction is generated, but since the pressure is smaller than that in the convex portion,
Since the frictional force between the sheet 13 and the elastic bodies 11 and 12 is small and the sheet transfer force is also small, the total sheet transfer force acts in the direction opposite to the traveling direction of the bending vibration described above.

FIG. 3 shows an example of an apparatus for generating the sheet transfer force as described above. In the figure, 11, 12 and 13 are the elastic bodies and sheets described above. Further, 14-1, 14-2, 15-1 (not shown), 15-2 are vibrators fixed on the elastic bodies 11, 12, 16 is a pressing support member, 17-1, 17-2 are The support side plate and 18 are bottom plates.

The elastic body 12 is supported by the bottom plate 18, and the elastic body 11 is supported by the pressing support member 16. Further, the elastic body 11 presses the sheet 13 with an appropriate force due to the spring property of the pressing support member 13, and holds the sheet 13 together with the elastic body 12. By applying a frequency voltage to each vibrator to the elastic bodies 11 and 12 and applying vibration, the convex portions are always opposed to each other as described above, and thus the sheet transfer force is generated. The sheet is conveyed in the direction of the arrow in the figure. Although the arrows in the figure indicate both directions, this means that the direction of sheet conveyance can be reversed by switching the traveling direction of vibration.

FIG. 4 and FIG. 5 show an example (only the main part is shown) of an apparatus in which the vibrating body is realized by another structure.

FIG. 4 shows a sheet made of track-like elastic bodies 20-1 and 20-2 to which track-like vibrators 19-1 and 19-2 are fixed.
It is configured to sandwich 13, and a sheet transfer force is generated by forming progressive bending vibration in the elastic bodies 20-1 and 20-2 by applying a frequency voltage to the vibrators 19-1 and 19-2. The points are the same as those of the device shown in FIG.

FIG. 5 is a sectional view of the apparatus shown in FIG. 4 as seen from the sheet feeding direction, and steps are provided on the left and right. This is an elastic body 20-
Since the direction of the sheet transfer force acts in the opposite direction on the left side and the right side of 1,20-2, to prevent the transfer force on the opposite side (the right side in FIG. 5) from acting on the sheet 13. is there.

By the way, in the conventional apparatus as described above, the sheet can be conveyed only in a specific direction. However, in recent years, in the above-mentioned various mechanical devices, there is a great demand for conveying a sheet in a plurality of directions, and the appearance of a device has been desired to meet this demand.

In view of this point, it can be realized by preparing a plurality of conventional devices as described above and arranging them so that the transfer force is generated in an arbitrary direction by the resultant force of these devices.
However, in this case, when it is desired to convey the sheet by the transfer force of only one of the plurality of devices, it is necessary to stop the vibration of the elastic body of the unnecessary device only between the sheet and the elastic body. A large frictional resistance is generated, and the frictional resistance causes a problem that a smooth sheet cannot be conveyed. In order to solve this problem, for example, in a device that does not require a transfer force, a method may be considered in which the gap between the opposing elastic bodies is widened to reduce the frictional resistance, but in this case, the gap is newly widened. A mechanism is required, the structure is complicated, and it is expensive.

(Object of the Invention) An object of the present invention is to smoothly carry out sheet conveyance in the same direction as the transfer force direction generated in any one of a plurality of elastic bodies with an inexpensive and simple configuration. It is to provide a sheet feeding device that can do this.

(Characteristics of the Invention) In order to achieve the above object, the present invention applies a plurality of elastic bodies arranged to generate a sheet transfer force in different directions due to the formation of traveling waves, and a frequency voltage. Then, when a wave is formed in each elastic body and a sheet conveyance instruction is made in the same direction as the transfer force direction generated in any one elastic body, the other elastic bodies are And a wave forming control means for forming a standing wave, thereby forming a standing wave in an elastic body that does not require a transfer force,
It is characterized in that the transfer force is made zero and the frictional resistance between the elastic body and the sheet, which is unnecessary, is reduced.

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

FIG. 1 shows an embodiment of the present invention, in which 1a, 2a,
3a and 4a are vibrators composed of piezoelectric elements, 5a and 6a are elastic bodies, 7a is an oscillator for applying a frequency voltage to the electric vibrators 1a to 4a, and 8a and 9a.
Is a switch, and 10a is an energy absorber.

The vibrators 1a and 2a are fixed to the elastic body 5a with an adhesive or the like. Similarly, the vibrators 3a and 4a are fixed to the elastic body 6a with an adhesive or the like. Further, the elastic bodies 5a and 6a are pressed by an appropriate force. In the embodiment, the elastic bodies 5a and 6a are connected to the ground circuit as conductors, and by applying a frequency voltage (AC electric field) to the vibrator 1a by the oscillator 7a, the elastic bodies 5a and 6a are connected.
Vibration occurs at 6a. The vibrators 2a and 4a are the elastic bodies 5a and 6a.
Generates power with the vibration of. When the switches 8a and 9a are closed, the generated electric energy is dissipated by the energy absorbing unit 10a including a resistor. Therefore, the vibration is not reflected but becomes a traveling wave. Elastic body 5a, 6a
When the bending vibration of B becomes a traveling wave, focusing on one point on the surface, the locus draws an ellipse as described above.
Therefore, the outer part of the bend always has a velocity component in the direction opposite to the traveling direction of the traveling wave, and the sheet always contacts the outer part of the bending, so that the direction opposite to the traveling direction of the traveling wave occurs. Sent. In FIG. 1, the carrying force is generated from left to right.

 The same operation is performed in 1b to 10b.

A case where the sheet is conveyed from the left to the right in the drawing in the above configuration will be described.

Only the transfer force generated in the device on the upper side in the figure needs to be applied to the sheet. Now, if the oscillator 7b is stopped in order to make the transfer force of the lower device zero, the elastic bodies 5b and 6b are pressed, so that a large frictional resistance is generated between the sheet and the elastic bodies 5b and 6b. As described above, smooth transportation cannot be performed.

Therefore, in this embodiment, the switches 8b and 9b provided in the lower device are opened, and the vibrators 2b and 4 are provided in the energy absorbing unit 10b.
Vibration is reflected without dissipating the electric energy generated in b, and a standing wave is formed in the elastic bodies 5b and 6b. When the standing wave is formed in this way, almost no transfer force is generated and the frictional resistance is reduced, so that the sheet can be smoothly conveyed from left to right.

On the contrary, when it is desired to generate the transfer force only in the lower device, it can be similarly realized by opening the switches 8a and 9a and closing the switches 8b and 9b.

Also, close both switches 8a, 9a and switches 8b, 9b,
By appropriately adjusting the amplitudes of the oscillators 7a and 7b, it becomes possible to carry the sheet in any direction determined by the resultant force of the transfer forces generated in the respective devices.

According to this embodiment, a standing wave is formed on the elastic body on the side where the transfer force is unnecessary, and a traveling wave is formed on the elastic body on the side requiring the transfer force (by switching the switch). With a simple structure and a low cost, it is possible to convey a sheet in any direction.

(Correspondence between the invention and the embodiment) In this embodiment, 5a, 6a, 5b, 6b is a plurality of elastic bodies of the present invention, oscillator 7a, 7b, switches 8a, 8b, 9a, 9b, energy absorption unit 10a, 10b. Respectively correspond to the wave formation control means.

(Modification) In the present embodiment, only the one-way feed is shown, but the two-way feed is possible with the following configuration.

(1) Reverse feed can also be performed by switching the circuit, that is, by exchanging the oscillator and the energy absorbing section.

(2) Providing elastic bodies in which the directions of the traveling waves are opposite for each axis (upper and lower devices), and bidirectional feed is performed. in this case,
When feeding in a certain direction, a standing wave is formed in one elastic body.

(Effects of the Invention) As described above, according to the present invention, a standing wave is formed in an elastic body that does not require a transfer force to make the transfer force zero, and the elastic body becomes unnecessary. Since the frictional resistance between the sheet and the sheet is reduced, the sheet conveyance in the same direction as the direction of the transfer force generated in any one of the plurality of elastic bodies is inexpensive and simple. This makes it possible to carry out smoothly.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, and FIG. 2 is a view for explaining the principle of sheet conveyance in this type of apparatus,
3 is a perspective view showing a structural example of a conventional device, FIG. 4 is a perspective view showing a structural example of another conventional device, and FIG. 5 is a sectional view taken in the sheet feeding direction of FIG. 1a, 1b, 2a, 2b, 3a, 3b, 4a, 4b …… Resonator, 5a, 5b, 6a, 6b ……
Elastic body, 7a, 7b ... Oscillator, 8a, 8b, 9a, 9b ... Switch,
10a, 10b …… Energy absorption part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroyuki Seki Inventor Hiroyuki Sekimaruko 3-30-2 Ota-ku, Tokyo Canon Inc. (72) Inventor Eiichi Yanagi 3-30-2 Shimomaruko Ota-ku, Tokyo Canon Inc. Within the corporation

Claims (1)

(57) [Claims] 1. A plurality of elastic bodies arranged so as to generate a sheet transfer force in different directions when a traveling wave is formed, and a frequency voltage is applied to form a wave in each elastic body. When a sheet conveying instruction is made in the same direction as the direction of the transfer force generated in any one elastic body, the other elastic bodies are provided with a wave formation control means for forming a standing wave. A sheet feeding device equipped.