JPS59177243A - Sheet feed device - Google Patents

Abstract

PURPOSE:To transfer sheets by applying transferring force to sheets so that paper jams may be made hardly occured, and the space for the layout of the arrangement is made small, by providing such an arrangement that a progressive wave is generated in resilient members by means of vibrators formed of piezo elements or the like, and sheets are pressed to these resilient members. CONSTITUTION:Piezo elements 1 through 4 are secured to resilient members 5, 6 with the use of adjexives or the like. The resilient members 5, 6 are connected, as electrical conductors, to an earth circuit, and an alternate electrical field is applied to vibrators 1, 3 by means of an oscillator 7. Vibrators 2, 4 are applied with an electrical field having a phase-shift of pi/2 phase shifter 10. Accordingly, the vibrators 1 through 4 applied with the electrical fields vibrate so that the resillient members 5, 6 vibrate. Since the vibators 1, 2 and the vibrators 3, 4 are respectively spaced by a predetermined distance such as, for example, a wavelength of (n + 1/4)lambda, a progressive wave advancing from an exhaust port 9 to a paper feed port 8 is generated in the resilient members 5, 6. With this arrangement sheets are fed in the direction opposite to the advancing direction of the progressive wave.

Description

[Detailed Description of the Invention] The present invention is applicable to computers, copying machines, printers, facsimiles,
The present invention relates to sheet feeding devices such as word processors, typewriters, and other various machines equipped with a mechanism for feeding sheets.

Conventionally, in this type of apparatus, the sheet feeding mechanism has been driven by a rubber roller, belt, or the like using a rotary drive source such as a motor. However, the feeding device using this method requires a large space for the arrangement of rubber rollers or belts, and has the disadvantage that the sheet is likely to get caught between rollers or belts, resulting in so-called jam phenomenon. It had a

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a novel sorting and feeding device that is improved in view of these drawbacks.

Another object of the present invention is to provide a sheet feeding device that can feed the sheet by forming traveling waves in an elastic body that clamps the sheet.

That is, the main structure of the present invention capable of achieving the above-mentioned object is a sheet feeding device in which the sheet is moved by an elastic body using a vibrator made of a piezoelectric material or the like.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an embodiment of the present invention. In the figure, 1, 2, 4, and 4 are vibrators made of piezoelectric elements, 5 and 6 are elastic bodies, 7 is an oscillator, 8 is a sheet feed port, and 9 is a sheet discharge port. Vibrator 1/2
The elastic body 5 is firmly fixed with adhesive or the like, and the vibrators 6 and 4 are similarly fixed to the elastic body 6. Also,
The elastic bodies 5 and 6 are held down with an appropriate force. In this embodiment, the elastic bodies 5 and 6 are connected as conductors to a ground circuit, and an oscillator 7 applies an alternating electric field to the vibrators 1 and 6. An alternating current electric field with a phase shift of i is applied through a phase shifter. Note that the effective values of the electric fields applied to the vibrators 1, 2, 6, and 4 are equal. The vibrators 1, 2, 6, and 4 to which an electric field is applied vibrate, causing the elastic bodies 5 and 6 to vibrate. Since the oscillators 1 and 2 and the oscillators 6 and 4 are installed with a wavelength of (+7)λ (n is a natural number), a traveling wave is formed from the discharge port 9 to the paper feed port 8. When the bending vibration of the elastic body 5/B becomes a traveling wave, if we focus on one point on its surface, its locus depicts an ellipse. Therefore, the outer part of the bend always has a velocity component in the opposite direction to the traveling direction of the traveling wave.
The sheet is always in contact with the outer part of the bend and is thus sent in the direction opposite to the direction of travel of the traveling wave.

In addition to the L piezoelectric ceramic, for example, a single crystal piezoelectric material, a polymer piezoelectric material, a magnetostrictive vibrator, a vibrator using electromagnetic force, etc. can be used as the vibrator.

Further, as the elastic body, various metal materials, plastics, rubber, and other materials can be selected depending on the fixed vibration frequency and elastic coefficient of the vibrator.

Further, FIGS. 6 and 4 show an example of a method of supporting the elastic body 5. Support rods protruding from both ends of the elastic bodies 5 and 6 are fixedly fixed with fixing screws 16 to be held.

FIG. 2 shows another embodiment of the present invention, in which a vibrator with a large electromechanical coupling coefficient, such as a piezoelectric ceramic, is used to generate vibrations in vibrators 1 and 6, and the vibrations cause other vibrations. The energy generated by the vibrators 2 and 4 at the end is dissipated by a resistor or the like. The vibrations are not reflected and become traveling waves.

FIG. 5 incorporates a piezoelectric ceramic within the feedback loop of the oscillator. R (resistance) and C (capacitor) ensure that only the necessary frequency oscillation occurs. Z is a matching impedance and is determined so as to increase the power supplied to the piezoelectric ceramic.

In the embodiments shown in FIGS. 6 and 7, a piezoelectric material 11 of approximately the same size as the elastic bodies 5 and 6 is fixed to the elastic bodies 5 and 6, and electrodes 10 are attached only to necessary parts to vibrate.

The embodiment shown in FIG. 8 improves energy efficiency by allowing the power consumed in the embodiment shown in FIG. 2 to be fed back and reused.

FIG. 9 shows an embodiment in which the lower elastic body B of the embodiment shown in FIG. 1 is made of a plate member with a small coefficient of friction.

According to this, the elastic body 5 can be implemented with only one, and the configuration can be simplified.

In FIG. 10, the upper elastic body 60 of the embodiment shown in FIG. 1 is made into a roller, and is constructed only of the elastic body 5, similar to the embodiment shown in FIG.

As explained above, according to the configuration of the present invention, sheets can be conveyed without using a rotationally driven device such as a roller or a belt, and sheet jamming phenomenon is eliminated.
Moreover, the space required for arrangement can be reduced.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing an embodiment of the present invention, Figures 2 and 6
Figures 7, 8, 9 and 10 are cross-sectional views showing other embodiments, Figure 6 is a cross-sectional view showing a method of supporting the elastic body, and Figure 4 is a side view thereof. , Figure 5 shows the oscillation circuit. In the figure, 1, 2, 3, and 4 are piezoelectric elements, 5 and 6 are elastic bodies, 7 is an oscillator, 10 is an electrode, and 11 is a piezoelectric material.0 Applicant: Canon Co., Ltd.

Claims (1)

[Claims] A sheet feeding device characterized in that a traveling wave is formed in an elastic body by a vibrator made of a piezoelectric material or the like, and the elastic body presses a sheet 1 to apply a conveying force to the sheet and cause the sheet to be conveyed.