JPH02209339A - Paper feeder - Google Patents

Abstract

PURPOSE:To secure such a paper feeder that is simple in structure, compact in size, lighter in weight and high in efficiency by constituting each projection in at least two loop positions of high-order flexural vibration, pressurizing a sheet of paper and holding it between for conveying. CONSTITUTION:Support grooves 15a, 15b of a vibrator 16 are installed in correspondence to a node position of the flexural vibration, and cylindrical projections 14a, 14b are set up in correspondence to a loop position of the flexural vibration. Then, the vibrator 16 is positioned and fixed by a support block 17 via the support grooves 15a, 15b. Thus, paper 18 is pressurized and placed on the cylindrical projections 14a, 14b and this support block 17, and an ac electric field in and around resonance frequency of the vibrator 16 is impressed on a piezoelectric body tightly attached to a prismatic vibrator constituting the vibrator 16. With this constitution, since the cylindrical projections 14a, 14b vibrates in describing an almost circular locus to the prismatic vibrator 16 within a vertical plane, the paper 18 can be moved in an arrow direction.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a paper feeding device that generates driving force using elastic vibrations caused by a piezoelectric body.

2. Description of the Related Art In recent years, paper feeding devices have attracted attention in which elastic vibrations are excited in a vibrating body made of a piezoelectric body 1 such as a piezoelectric ceramic, and this vibration is used as a driving force.

Hereinafter, the conventional technology of a paper feeding device will be explained with reference to the drawings.

In conventional paper feeding devices, a vibrating body is constructed by bonding a piezoelectric material such as a piezoelectric ceramic to a flat elastic material such as metal.
A longitudinal vibration mode and a flexural vibration mode with equal resonance frequencies of the flat plate are simultaneously excited in the vibrating body to create an elliptical locus at a certain point on the flat plate, and the paper is held between the rollers at the apex of the elliptical locus. It is something to send.

FIG. 4 is a displacement distribution diagram of the longitudinal vibration mode and the bending vibration mode, which have the same resonance frequency and are excited in the flat plate. Figure (a)
is the displacement distribution 2 of the longitudinal vibration mode of the flat plate vibrating body 1, and (b) is the displacement distribution 3 of the bending vibration mode of the flat plate vibrating body 1.
It is. The arrows in the figure indicate the direction of vibration displacement at a certain time. Vertical vibration creates horizontal movement, and flexural vibration creates vertical movement. Therefore, in the shaded area in the figure, an elliptical locus with a large lateral component due to the longitudinal vibration mode is obtained.

Figure 5 is an overview of the paper feeding device using the vibration mode shown in Figure 1, with (a) showing the charge distribution and (b)
shows the piezoelectric body position corresponding to the charge and the structure of the paper feeding device. The piezoelectric body 8 is attached to the elastic flat plate 6 corresponding to the charge distribution in the longitudinal vibration mode, and the piezoelectric bodies 7a, 7b, 7c, and 7d are attached to the elastic flat plate 6 in accordance with the charge distribution 5 in the flexural vibration mode to vibrate. It makes up the body. Then, the paper 10 is pressed and pinched by the rollers 9a and 9b, respectively, at the diagonally shaded portions where an elliptical locus with a large lateral component in FIG. 4 is obtained. By applying an electric field to the piezoelectric body 7.8, the photographing body is excited to move the paper 10.

Problems to be Solved by the Invention As described above, the conventional paper feeding device described above must vibrate a flat plate having a large mass in order to move paper having a small mass. Also, since it uses two different vibration modes: longitudinal vibration mode and flexural vibration mode,
In order to match the resonance frequencies of the two vibration modes, the amplitude of one of the two vibrations becomes smaller.Also, since the vibration node is located in the center of the vibrating body, it is difficult to fix the position. However, there were problems with low efficiency and large dimensions and weight.

Means for Solving the Problems The present invention configures a vibrating body by bonding piezoelectric bodies to adjacent main surfaces of a prismatic elastic body, and applies an electric field to the piezoelectric body to cause the vibrating body to 2 where the vibration planes are spatially orthogonal
excite two high-order bending vibrations, fix the position of the object to be photographed via at least two nodes of the high-order bending vibrations, and fix the position of the object to be photographed through at least two nodes of the high-order bending vibrations; A protrusion is formed on the protrusion, and the paper is pressurized and sandwiched between the protrusion and the flat plate to move the paper.

By changing the active vibrating body from a conventional flat plate to a prism, the shape and weight are reduced (and by adopting the same mode of vibration from the longitudinal vibration mode and the flexural vibration mode as the imaging mode, the two vibration modes are reduced). It becomes easier to match the resonant frequencies, and as a result, vibrations can be excited efficiently, and since the nodes of the two vibrations match, it becomes easier to fix the position of the vibrating body.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram of a photographing object according to an embodiment of the present invention.

11 is a prismatic elastic body made of metal etc., 12a, 12b
, 12c, 12d, 12e, and 12f are piezoelectric bodies fixed to the prismatic elastic body 11 in order to excite high-order deflection imaging;
Also 13a, 13b, 13c, 13d, 13e, 13f
is a group of piezoelectric bodies fixed to the prismatic elastic body 11 in order to excite high-order deflection motion perpendicular to the above-mentioned high-order deflection motion, and these piezoelectric bodies are polarized in the thickness direction. . 14
A and 14b are cylindrical projections, 15a and 15k) are support grooves, and constitute a vibrating body 16. The pressure in the same figure! The positive and negative signs attached to the body groups indicate the direction of polarization of the piezoelectric body.

FIG. 2 shows a displacement distribution of high-order bending vibration excited in the vibrating body shown in FIG. 1. FIG. The displacement distribution shown in the figure is the displacement distribution when an electric field is applied to and driven the piezoelectric group 12 or 13.If both piezoelectric groups are driven, the displacement distribution orthogonal to the displacement distribution shown in the figure can be obtained simultaneously. Can be excited. Support groove 15a
・15b is installed corresponding to the nodal position of the above-mentioned bending vibration,
The cylindrical projections 14a and 14b are installed corresponding to the antinode position of the bending vibration. If the piezoelectric body groups 12 and 13 are simultaneously driven by two electric fields with a phase difference of 90 degrees, the cylindrical protrusions 14a and 14b will move into the prismatic vibrating body 1 due to mutually orthogonal bending vibrations.
It vibrates in a nearly circular locus in a plane perpendicular to 6.

FIG. 3 shows an example of the structure of a paper feeding device using the above-mentioned moving body. The vibrating body 16 has support grooves 15a and 15b.
The position is fixed by the support stand 17 via. Paper 18 is placed under pressure on the cylindrical projections 14a and 14b and the support base 17, and by applying an alternating current electric field near the resonance frequency of the vibrating body 16 to the piezoelectric body groups 12 and 13, the cylindrical projection 14
Since a and 14b vibrate in a plane perpendicular to the prismatic vibrating body 16, drawing a substantially circular locus, the paper 18 moves in the direction of the arrow in the figure.

In this embodiment, the piezoelectric body group shown above is used, but any piezoelectric body from the piezoelectric body groups 12a to 12f or 13a to 13f may be thinned out. In addition, in this example, high-order deflection imaging of a prism with both ends free is used as the vibration mode, but a higher-order mode can also be used, or high-order deflection imaging with both ends fixed is used. The paper feeding device can also be configured in the same way.

Effects of the Invention As described above, according to the present invention, it is possible to provide a paper feeding device with a simple structure, small size, light weight, and high efficiency.

[Brief explanation of the drawing]

Fig. 1 is an overview of a vibrating body according to an embodiment of the present invention, Fig. 2 is a displacement distribution diagram of high-order bending vibration of the vibrating body of Fig. 1, and Fig. 3 is a diagram using the vibrating body of Fig. 1. Fig. 4 is a diagram showing the displacement distribution of the longitudinal vibration mode and bending vibration mode of the vibrating body of the conventional paper feeding device, and Fig. 5 shows the vibration mode shown in Fig. 1. FIG. 2 is an overview diagram of the paper feeding device used. 11...Prismatic elastic body, 12a, 12b, 12c
・12d・12e・12f・・・Piezoelectric body group, 13
a, 13b, 13C, 13d, 13e, 13f...
...Piezoelectric body group, 14a, 14b...Cylindrical projection,
15a/15b...Support groove, 16...
Vibrating body, 17... Support stand, 18... Paper. Name of agent: Patent attorney Shigetaka Awano and one other figure 43 Figure 4 (a) Figure!

Claims (1)

[Claims] A vibrating body is constructed by bonding a piezoelectric body to adjacent main surfaces of a prismatic elastic body, and by applying an electric field to the piezoelectric body, two heights whose vibration planes are spatially perpendicular to the vibrating body are created. Excite the following flexural vibrations, and at least 2 of the above higher-order flexural vibrations.
The vibrating body is fixed in position via two nodes, protrusions are formed at at least two antinode positions of the high-order bending vibration, and the paper is pressurized and sandwiched between the protrusions and the flat plate, and the paper is moved. A paper feeding device characterized by: