JPH0476894B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for conveying sheets such as original documents and recording paper, such as copying machines, facsimile transceivers, printing machines, and line printers.

An example of a conventional device of this type for conveying a document sheet of a facsimile transmitter is shown in FIG. 1 and will be described.

An operator places a document sheet 1 on a document table 2, and pushes the sheet 1 out until it is pressed against the document table 2 by a take-in roller 3. The sheet 1 is taken in by the pressure rotation of the roller 3 driven by a motor (not shown), and the sheet 1 is taken in by the conveying rollers 4 and 5.
is nipped and sent to the reading section 14. The sent original sheet is illuminated by a fluorescent lamp 6, and the reflected light is reflected by a mirror 10 and an imaging lens system 1.
1, the image is formed on a charge couple device (CCD) 12 of a photoelectric conversion element and read. The optical signal of the read original sheet is converted into a scanning electric signal by the CCD 12, and after being subjected to necessary processing such as amplification, it is transmitted according to a conventional method. While being read in this manner, the sheet 1 is conveyed over the discharge tray 7 by rollers 4 and 5, and is discharged by discharge rollers 8 and 9.

In such a device, the operator forgets to push the document sheet out until it comes into contact with the take-in roller 3, and the document sheet remains on the document table 2, which is mistaken as a malfunction in the device. Sometimes. Also, it should be remembered that the operation of pushing out the original sheet itself is troublesome.

In order to avoid such inconvenience, there is a structure in which the original platen 2 is tilted as shown by the chain line and the original sheet is slid by its own weight and taken into the taking-in roller 3. However, if the document table is tilted, operability for the operator will be poor. In addition, the loading operation is affected by the frictional force between the sheet and the document table, the thickness of the sheet, and the stiffness of the sheet, causing trouble.

In addition to this, various other devices for conveying sheets have been proposed and commercialized. In all of these, the sheet is conveyed by the frictional conveying force of rollers or belts rotationally driven by a motor. A transmission system such as gears is required to transmit rotational force from the motor to the rollers and belts.

As a result, the sound generated by the transmission system can become a noise in quiet offices, and foreign objects can get stuck in the transmission system, causing it to malfunction. Furthermore, when manufacturing the device, it is necessary to fine-tune the transmission system and the amount of pressure applied by the rollers for each product, which makes the device expensive and time-consuming.

The present invention has been made for the purpose of eliminating the above-mentioned drawbacks of conventional sheet conveying devices.

Embodiments of the present invention will be described in detail below to clarify the structure of the present invention.

FIG. 2 is a perspective view of an embodiment of a sheet conveying device to facilitate understanding of the present invention.

In the figure, a photoelectric switch 25 attached to the sheet table 17 is turned on for the sheet 1 placed on the original sheet table 17. As a result, an electrostrictive element 19 (not shown in the figure) placed in contact with the back surface of the vibrating body 18 slightly protruding from the cutout surface of the seat base 17 is energized.
The electrostrictive element 19 excites the vibrating body 18 to generate progressive surface vibration waves. The sheet 1 moves in the direction of the reading section 14 (arrow X direction) due to its progressive surface vibration waves.
transported to. The conveyed original sheet is illuminated with a fluorescent lamp 6 as in conventional equipment, and is illuminated with a mirror 1.
0. The light enters the CCD 12 through the lens 11 and is read. The read original sheet is discharged onto a discharge tray 7 by rollers 5 and conveyed.

FIG. 3 shows details of a portion of the vibrating body 18 and the electrostrictive element 19, which generate progressive surface vibration waves, as viewed obliquely from below. In the figure, the electrostrictive element 19 is, for example, PZT (lead zirconium titanate). The vibrating body 18 is made of an elastic material such as aluminum, brass, or steel plate, and has an electrostrictive element 19 bonded thereto, and its front and rear ends are held by vibration absorbers (not shown) such as rubber. The electrostrictive element 19 is polarized into a plurality of polarities. In the figure, + and - indicate polarity. One polarization group 19A of the electrostrictive element 19 and the other polarization group 19B have a wavelength λ of 1/2 of the vibrating body within each group.
It is polarized at a pitch of nλ/2, which is an integer multiple of the wavelength. (n
= 1.2.3...The figure is for λ/2 pitch). Also, for one group 19A, for the other group 19B, (n ₀ +1/4)λ
It is polarized at a shifted pitch (n ₀ =0.1.2.3...The figure shows the case of λ/4). On the surface of the electrostrictive element 19, electrodes 20A and 21A having comb teeth are provided at every other polarization pitch in the polarization group 19A, and similar electrodes 20B and 21B are provided in each polarization pitch in the polarization group 19B. , provided. The AC power supply 23 is connected to the comb tooth electrodes 20A and 21A and a 90° phase shifter 24 through a photoelectric switch 25, and the output of the 90° phase shifter 24 is connected to the comb tooth electrodes 20B and 21B.

In such a sheet conveying device, the photoelectric switch 2
5 is closed, one polarization group 1 of the electrostrictive element 19
An AC voltage of VoSinωT is applied to 9A from an AC power supply 23, and a 90° phase shifter 2 is applied to the other group 19B.
4, an AC voltage of VoCosωT is applied.
Therefore, a forward electric field is applied to every other adjacent polarization in the polarization group 19A, and an opposite electric field is applied to every other remaining polarization. In the polarization group 19B, a forward electric field is applied to every other adjacent polarization, and an opposite electric field is applied to every other remaining polarization. AC electric fields with a phase shift of 90° are applied between the two groups 19A and 19B.

The electrostrictive element expands in the polarization direction when an electric field is applied in the forward direction of the polarization direction, and contracts when an electric field is applied in the opposite direction. Under the above AC electric field, if it expands at every other polarization position, it will contract at every other polarization position, and if it expands at every other polarization position with a 90° phase shift, it will contract at every other polarization position. Shrinks at the polarization position.

FIG. 4 shows a state in which this expansion and contraction is transmitted to the vibrating body and progressive surface vibration waves are generated. In the figure, each polarization group 19A and 19B of the electrostrictive element 19
are shown adjacent to each other for convenience of explanation, but since they satisfy the above-mentioned phase shift condition of λ/4, they are similar to the arrangement of the polarization groups 19A and 19B of the electrostrictive element 19 shown in FIG. They are substantially equivalent. Now, if only the polarization group 19A is expanded or contracted by the voltage VoSinωT, surface vibrations due to standing waves as shown in FIG. When only the polarization group 19B oscillates due to the voltage VocosωT, oscillations due to standing waves as shown in b occur. When two standing wave vibrations occur one after another, the vibration waves are combined and travel on the surface of the vibrating body 18. (a) is time T = 2nπ/ω,
(b) is T=π/2ω+2nπ/ω, (c) is T=π/ω+
2bπ/ω, (d) indicates the state of the vibration wave when T=3π/2ω+2nπ/ω. The wavefront of the surface vibration wave travels along the lower surface of the vibrating body 18 in the x direction. When it goes around the pole of the vibrating body 18, it moves along the upper surface in the -x direction (the third
(see figure). As you progress to the tip of the top surface in the -x direction,
It travels again along the lower surface in the x direction and then merges with the excited wave.

Such progressive surface vibration waves are accompanied by longitudinal waves and transverse waves, and if we focus on the mass points A ₁ , A ₂ , A _{3 .} . . on the upper surface of the vibrating body 18 as shown in FIG.
It is moving in a counterclockwise rotational ellipse with a vertical amplitude u and a horizontal amplitude w. The sheet 1 is in contact with the surface of the vibrating body 18. The sheet 1 is conveyed in the direction of the arrow X by being frictionally driven by the longitudinal amplitude u component of the elliptical motion of the mass points A ₁ , A ₂ , A _{3 .} . . on the surface.

In this way, this sheet conveying device does not use a drive motor, transmission system, or rotating roller, so
There is no rotation noise. There is no need to adjust the pressure contact amount of the roller or any other rotating parts.

FIG. 6 shows an embodiment of the invention. In this embodiment, sheets are fed in the X and Y directions. Since the sixth illustrated example is the same in principle as the second to fifth illustrated examples, the same elements are given the same reference numerals, and only the differences between the two will be mainly explained. At the end of the sheet table 17 in the Y direction, there is a folded part 17a as a sheet guide, and at the end in the X direction, there is a reading part 14 as in the previous example. The sheet stand 17 has a vibrating body 31 for conveying the sheet in the X direction.
and 32, and vibrating bodies 33 and 34 for conveying in the Y direction are arranged. Each vibrating body 31, 3
Electrostrictive elements are arranged at 2, 33, and 34 as in the previous example.

When a sheet is placed on the seat base 17 and the vibrating bodies 31, 32, 33, and 34 are vibrated by each electrostrictive element, the sheet moves in the X direction and the Y direction. When the sheet comes into contact with the folded portion 17a, the sheet no longer moves in the Y direction, but advances in the X direction along with the folded portion 17a. Therefore, even if the position where the sheet is placed is slightly shifted or twisted, the device will automatically correct the direction of travel.

FIG. 7 shows another embodiment, in which the seat base 1
A sheet restraining plate 35 is provided so as to sandwich the sheet 1 on top of the sheet 7, and is urged downward by a spring 36. Seat stand 1
A vibrating body 37 to which an electrostrictive element 39 is bonded is disposed at 7, and a vibrating body 38 to which an electrostrictive element 40 is bonded to the holding plate 35 is disposed. The sheet 1 receives a conveying force from both the sheet table 17 and the holding plate 35. The holding plate 35 may be provided with a folded portion 35a so as to easily receive the sheet.

As explained above, when the device of the present invention is used, there is no noise because there are no mechanical sliding parts such as rollers, and the device is ideal for office machines used in offices and the like. In addition, the sheet and the sheet base that bends and vibrates come into contact with each other on the surface or at multiple points, and the document is transported by the friction, so sheets of various thicknesses and stiffness can be handled more easily than with conventional methods such as rollers. Can be used for transportation. Furthermore, not only can skewing of the sheet be prevented, but also the seat base and the vibrating body are separate members, so there are no restrictions on the shape of the seat base.

[Brief explanation of the drawing]

Figure 1 is a side view of a conventional sheet conveying device;
The figure is a perspective view of an embodiment of the sheet conveying device to facilitate understanding of the present invention, FIG. 3 is an enlarged perspective view of the main part thereof, and FIGS. 4 and 5 are diagrams explaining progressive surface vibration waves. , FIG. 6 is a perspective view of a main part of an embodiment of the present invention, and FIG. 7 is a side view of a main part of another embodiment. 1 is a seat, 17 is a seat base, 18 is a vibrating body,
19 is an electrostrictive element, 23 is an AC power supply, and 24 is a 90° phase shifter.

Claims (1)

[Claims] 1. A sheet stand on which a sheet to be fed is pressed, a first vibrating body provided on the sheet stand and generating a progressive vibration wave that propagates in a direction along the sheet conveyance direction, and a A seat characterized by having a second vibrating body that generates progressive vibration waves in a traveling direction having a predetermined angle with the direction of the vibration waves generated in the first vibrating body, and a sheet guide provided at a predetermined position. Conveyance device.