JPH0729701B2 - Paper feeder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sheet feeding device that is compact, quiet, has a wide feed amount setting range, and is capable of forward and reverse rotation feeding.

[Conventional technology]

Since the conventional paper feeding device uses a pulse motor or a DC motor, the paper feeding device is generally large in size, and requires a gear and a clutch, so that the operation noise is large.

FIG. 7 shows an example of a conventional sheet feeding device, in which 1 is a sheet, 2 is a platen, 3 is a pressure roller, 4 is a pulse motor, and 5 is a reduction gear.

In these operations, the rotation of the pulse motor 4 at a constant angle is transmitted to the platen 2 via the reduction gear 5, and the pressure
The sheet 1 held by the roller 3 moves in the direction of the arrow together with the platen 2.

(Problems to be Solved by the Invention) As described above, since the pulse motor 4 or the DC motor and the platen 2 are conventionally used, the paper feeding device is
The size is large, and there is a limit to downsizing, especially thinning.

Further, since it is inevitable to use the reduction gear 5 and the clutch, there is a drawback that noise is generated during operation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a compact and quiet printer by reducing the size and thickness of a sheet feeding device and reducing noise.

[Means for solving problems]

A sheet feeding device according to the present invention comprises a multi-joint link in which a mounting portion, a first link, and a second link are connected one after another by a rotation center, and a length of which is changed by energization and a pressing end portion are stacked. -Shaped first and second piezoelectric elements are fixed to the mounting portion and the first link, respectively, so that the first link can rotate in response to changes in the length of the first piezoelectric element. A first spring is used to couple the attachment portion and the arm of the first link so that the second link can rotate in response to a change in the length of the second piezoelectric element. A structure in which the first link and the arm of the second link are coupled using a second spring, and a contact portion is provided on the lower end side of the second link via a leaf spring. Is.

[Action]

In the present invention, by driving each piezoelectric element, the contact portion moves forward while contacting the paper, and then the reciprocating motion of returning without contact is repeated to feed the paper little by little.

〔Example〕

FIG. 1 is a side view for explaining the first embodiment of the present invention,
1 is paper, 6 and 7 are laminated piezoelectric elements, 8 and 9 are pressing ends, 1
Reference numerals 0 and 11 are arms, 12 and 13 are springs, 14 is a base, 15 is a mounting portion for the piezoelectric element 6, 16 and 17 are links, and the link 16 also serves as a mounting portion for the piezoelectric element 7. Reference numeral 18 is a leaf spring joined to the end of the link 17, 19 is a contact portion made of rubber, and 20 is a paper guide, which is fixed to the base 14.

FIG. 2 is a perspective view showing the shape of the pressing ends 8 and 9.

FIG. 3 is a diagram for explaining the operation of the above-described embodiment.
A, b, b1, b2, which are also shown in the figure, are the centers of rotation of links 16 and 17,
c, c1, c2, c3 indicate the positions of the tips of the contact portions 19.

First, the state of FIG. 1 will be represented as (a, b, c). When the piezoelectric element 7 is driven in the contracting direction from this state, the spring 13
Force causes the arm 11 and the link 17 to rotate counterclockwise, and the contact portion 19 separates from the sheet 1. This state can be represented as (a, b1, c3) in FIG. 3, for example. Now, when the contact portion 19 does not have the paper 1 and the paper guide 20,
Consider taking an elliptical route. For example root
When taking 21, the piezoelectric element 6 is driven and the rotation center b is set to b1.
It can be seen from the figure that the piezoelectric element 7 may be appropriately driven so as to move from the position to the point b2. Paper 1 and paper guide 20
If there is any, the tip of the contact portion 19 can follow the loop formed by the upper portion of the route 21 and the route 22 shown by the bold line in FIG. However, the error due to the deflection of the leaf spring 18 is omitted. Of course, it is possible to further reduce the deflection of the leaf spring 18, and in that case, the route of the tip of the contact portion 19 when the sheet 1 and the sheet guide 20 are not present is the route 23 shown by the two-dot chain line in FIG. It may be controlled to pass through.

FIG. 5 is a partial side view showing another embodiment of the present invention.
The flexible connecting member is used instead of the pressing ends 8 and the springs 12 and 13 of the piezoelectric elements 6 and 7 in FIG. That is, the piezoelectric elements 6 and 7 and the arms 10 and 11 are connected to each other.
By directly connecting at 24, the same effect as the embodiment of FIG. 2 is obtained, and in the embodiment of FIG. 2, when the driving force of the springs 12 and 13 is insufficient depending on the load or the operating speed. , It is possible that the intended action is not performed. In this embodiment, this point is improved so that a reliable operation can be performed both back and forth.

The above description has been made for one sheet feeding device.
For a sheet-like material having a horizontal width, it is necessary to feed both ends at the same time for stable feeding. Therefore, normally, a total of four sheet feeding devices, two at a time, are provided at both ends of the sheet 1, and these are simultaneously operated as a set of two at both ends.
Since 19 always contacts the paper 1, stable feeding can be performed.

The contact portion 19 may have a claw portion made of a highly wear-resistant material such as metal or ceramic as shown in FIG. 6, or the sheet 1 may be processed by another method. Anything that can be held by (Route 22 in FIG. 4) may be used.

Further, although the driving direction is the left direction in the drawings, the driving direction can be right. The embodiment of FIG. 1 can be driven in both left and right directions, but the contact portion of FIG. 6 is suitable only in the left direction.

In the above embodiment, the control means for energizing and de-energizing the piezoelectric elements 6 and 7 to cause the links 16 and 17 to perform a predetermined motion as shown in FIG. 3 is omitted.

〔The invention's effect〕

As described above, according to the present invention, the attachment portion (15), the first link (16), and the second link (17) are sequentially connected by the rotation centers (a, b) to form a multi-joint link. Then, the laminated first and second piezoelectric elements (6, 7) whose length is changed by energization and which have the pressing ends (8, 9) are attached to the mounting portion (15) and the first link ( 16), each of which is fixed to the mounting portion (1) using a first spring (12) so that the first link (16) can rotate in response to a change in the length of the first piezoelectric element. 15) and the arm (10) of the first link (16) are coupled so that the second link (17) can rotate in response to the change in the length of the second piezoelectric element. A second spring (13) is used to connect the first link (16) and the arm (11) of the second link (17), and the lower end of the second link (17) is The contact portion via a spring (18) (19) is provided, it is possible to construct a paper feed apparatus compact, lightweight. In particular, when feeding at a fine pitch like a line dot printer, there is no need to use a reduction gear, and there is an advantage that noise is not generated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of an embodiment of the present invention, and FIG.
FIG. 3, FIG. 4 and FIG. 6 are partial perspective views of the main part of the drawing, and FIG. 5, FIG. 6 and FIG.
FIG. 7 is a partial side view of another embodiment of the present invention, and FIG. 7 is a perspective view showing an example of a conventional sheet feeding device using a pulse motor. In the figure, 1 is a sheet, 6 and 7 are laminated piezoelectric elements, 8 and 9 are pressing ends, 10 and 11 are arms, 12 and 13 are springs, 14 is a base, 15 is a mounting part, and 16 and 17 are Link, 18 is a leaf spring, 19 is a contact portion, 20 is a paper guide, 21, 22 and 23 are movement routes of the tip of the contact portion, a, b
Is the center of rotation of the link, and c is the tip of the contact portion.

Claims (1)

[Claims] 1. A multi-joint link is formed by connecting a mounting portion (15), a first link (16) and a second link (17) one after another by means of a center of rotation (a, b), which is long by energization. Fixing laminated first and second piezoelectric elements (6, 7) having varying pressures and pressing ends (8, 9) to the mounting portion (15) and the first link (16), respectively. Then, a first spring (12) is used so that the first link (16) can rotate in response to a change in the length of the first piezoelectric element, and the attachment portion (15) and the first The second link (17) is connected to the arm (10) of the first link (16) so that the second link (17) can rotate in response to the change in the length of the second piezoelectric element. 13) is used to connect the first link (16) and the arm (11) of the second link (17), and a leaf spring (18) is provided on the lower end side of the second link (17). Connect through A paper feeding device characterized in that a touching portion (19) is provided.