JPH03182432A - Automatic sheet feeder - Google Patents

Abstract

PURPOSE:To limit the skew direction of a sheet in only one direction and prevent the sheet from being skewed in the undesirable direction by operating a lifting means in the direction that sheet feed rollers approach to a sheet feed bed at the rotation position where a shaft is detected. CONSTITUTION:Rear ends 19c of no-drive regions 19a of multiple roller elements 19 differ in phase from one shaft end to the other shaft end in sequence. The driving force is transmitted to a sheet 23 in sequence from the roller element 19 with the most advanced phase. When the roller elements 19... with the advanced phase at the rear ends 19c of the no-drive regions 19a are arranged in sequence from the right side of a shaft 18, the sheet 23 is delivered so that the right side precedes, and there is no fear at all that the sheet 23 is obliquely delivered in the direction that the left side precedes.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device that automatically feeds sheet-like paper (cut paper) serving as an information medium to a printer or the like of an information processing device.

(Prior Art) Fig. 3 is a diagram schematically showing a printer equipped with an automatic paper feeding device for sheet paper, in which l is a print head, 2 is a platen, and 3 is a connection between print head 1 and platen 2. 4 and 5 are paper feed rollers located before and after the print section 3, and 6 detects the paper just before the paper feed roller 4 on the paper feed side. A paper feed side sensor; 7 is a paper discharge side sensor that detects paper immediately after the paper feed roller 5 on the paper discharge side;
8 is a paper feed table, 9 is a pulse motor 10 and a rack and pinion 1
1 is a paper feed table elevating mechanism, 12 is a swing frame pivotally supported on a fulcrum bin 13, 14 is a paper feed roller pivoted to the seeding end of the swing frame 12, and 15 is a swing frame 12. 16 is a stopper for regulating the lowering position of the swing frame 12; limit 7 for detecting the upward movement of the swing frame 12
It's a toss inch.

The feed roller 14 typically includes a plurality of roller elements 19 fixed to a shaft 18, as shown in FIG. 20 is a pulse motor for driving the paper feed roller, 21 is its rotation transmission mechanism, and 22 is a one-way clutch. The sensor 6.7 for detecting the paper sheet is usually arranged close to the left side of the paper path, which is the starting point for measuring the printing position.

In such a device, the paper feed roller 14 is rotated forward with the paper feed roller 4 on the paper feed side stopped or rotated in reverse to feed the paper 23, and after the leading edge of the paper is detected by the paper feed side sensor 6. Then, after rotating the paper feed roller 14 by a predetermined amount to bend the leading edge of the paper between the paper feed roller 14 and the paper feed roller 4 on the paper feed side, the paper feed roller 4.5 is rotated in the normal direction. There is a known means for correcting the skew of the paper by feeding the paper 23 into the printing unit 3 so that the leading edge of the fed paper follows the paper feed roller 4 on the paper feed side.

(Problems to be Solved by the Invention) In this case, when the right side of the paper is skewed in the preceding direction, as shown by the solid line in FIG. 4, the skew can be reliably corrected. However, when the left side of the paper is greatly skewed in the leading direction, even if the left side of the leading edge of the paper is detected by the paper feed side sensor 6 and the paper is further fed a predetermined amount, the right side of the leading edge of the paper will be on the paper feeding side. It may happen that the paper does not reach the position of the paper feed roller 4, and in this case, the skew of the paper cannot be corrected.

The present invention makes it possible to avoid the above-mentioned problems by providing an automatic paper feeder in which the paper does not skew in an undesirable direction.

(Means for Solving the Problems) The automatic paper feeding device of the present invention includes a non-driving area 19a on a part of the circumferential surface as a plurality of roller elements constituting the paper feeding roller 14.
A roller element 19.27 provided with 27a is used. The non-drive area 19a, '27a is, for example, a roller element 19.
It is formed by cutting out a part of the circumferential surface of 27 or by providing a member with a low coefficient of friction on a part of the circumferential surface. A plurality of roller elements 19, 27, . The phase is sequentially shifted toward the end side.

An origin detecting means 25 for detecting the rotational position of the shaft 18 when the non-driving areas 19a, 27a of all the roller elements are in contact with the paper 23 is provided on the shaft 18 or its drive system.

The paper feed tray 8 and the paper feed roller 14 have a structure in which the paper 23 on the paper feed tray 8 and the paper feed roller 14 are brought into contact with each other and separated by widening and narrowing the gap therebetween, and the detected rotation of the shaft 8 is The paper 23 and paper feed roller 14 are brought into contact at this position. That is, the non-driven areas 19a, 2 of all roller elements 19.27
The sheet feeding operation is started with the state in which the sheet 7a is in contact with the sheet as the starting point.

(Function) The paper 23 on the paper feed table 8 and the paper feed roller 14 come into contact with each other at the non-driving areas 19a, 27a of the roller elements 19.27, and then the paper feed roller 14 rotates to drive the paper feed roller. The areas 19b and 27b come into contact with the paper 23, and the paper 23 is sent out. At this time, the non-driving area 1 of the plurality of roller elements
Rear ends of 9a and 27a (front ends of drive areas 19b and 27b)
19C127C has a phase shift sequentially from one shaft end to the other shaft end, so the driving force is transmitted to the paper 23 in order from the roller element with the most advanced phase. Therefore, from the right side of the shaft 18, the rear ends 19c, 27c of the non-driving area of the roller element 19.
27..., the paper 23 will be fed out with the right side leading, and there will be no possibility that the paper will be fed obliquely in the direction in which the left side is leading, and the left side of the paper will be in the lead. It is possible to prevent the skew of the paper from becoming uncorrectable due to the skew of the direction.

(Embodiment) FIGS. 1 to 5 show an embodiment of the present invention, in which 19a is a chamfered portion provided on a part of the circumferential surface of a short cylindrical roller element 19, and 19b is a cylindrical portion. , 19c is an edge on the rear side (opposite paper feeding side) of the chamfered portion 19a, 24 is a slit disk fixed to the shaft 18, and 25 is a photoelectric sensor for detecting the slit 26 of the slit disk 24. Other symbols have been explained in the prior art section.

A plurality of roller elements 19 fixed to the shaft 18 are
As shown in FIG. 2, the rear end 19C of the chamfered portion 19a is arranged so that the phase thereof is sequentially delayed from the right side of the shaft 18 (closer to the right side of the paper) to the left side. The slit disk 24 is fixed to the shaft 18 so that the slit 26 is detected by the photoelectric sensor 25 when the chamfered portions 19a of all roller elements face the paper 23. The arrow in FIG. 2 indicates the rotation direction of the paper feed roller 14.

The paper feeding operation of the paper 23 is performed according to the procedure shown in FIG.

That is, the paper feed roller 4 is rotated (step A), and the position of the slit 26 is detected by the photoelectric sensor 25 (step B).
, the rotational position of the shaft 18 of the paper feed roller is positioned at the origin (step C). Next, the paper feed tray 8 is raised (step D>, the raising of the paper feed tray is confirmed using the limit switch 16 (step E)), and then the raising operation is stopped (step F). With the above operation, the paper 23 on the paper feed tray 8 comes into contact with the non-driving areas 19a of all the roller elements 19.

Then, while the paper feed roller 4 on the paper feed side is stopped or rotated in reverse, the paper feed roller 14 is rotated forward (Step G), and the paper 23 is fed, and the leading edge of the paper is detected by the paper feed side sensor 6 (Step H). After the paper feed roller 14 is rotated by a predetermined amount (step I), the leading edge of the paper is bent between the paper feed roller 14 and the paper feed roller 4 on the paper feed side. 5 in the forward direction (step J) to feed the paper 23 into the printing section 3, and at the same time lower the paper feed table 8 by a certain pulse amount (step K).
Then, predetermined printing processing is performed by line feed feed and operation of the print head 1 (step L), and when the printing processing is completed and the sensor 7 detects the ejection of the printed paper (step P), the next paper is fed. Enter the paper action.

FIG. 6 shows another means for forming a non-driving area on a part of the circumferential surface of the roller element of the paper feed roller 14, in which a part 27a of the circumferential surface of the roller element 27 is made of plastic.
The other region 27b is made of rubber. Paper 23
When the paper feed roller 14 and the paper feed roller 14 are in contact with the plastic portion 27a, the friction between the two is small, so even if the roller element 27 rotates, no driving force is transmitted to the paper, and the drive force is not transmitted to the paper until it comes into contact with the rubber portion 27b. Since a paper feeding force is applied to the paper 23, the same effect as in the case where the chamfered portion 19a described above is provided is achieved.

(Effects of the Invention) According to the automatic paper feeder of the present invention described above, the oblique direction of the fed paper can be restricted to only one direction.
It is possible to prevent the paper from skewing in an undesirable direction, and it is possible to avoid troubles caused by the skewing of the paper in an undesirable direction.

[Brief explanation of drawings]

1 to 5 are diagrams showing a first embodiment of the present invention, in which FIG. 1 is a perspective view of the paper feed roller, FIG. 2 is an enlarged side view of the paper feed roller, and FIG. 3 is an automatic feed roller. It is a flowchart showing paper binding. FIG. 6 is an enlarged side view of a paper feed roller showing a second embodiment of the present invention. In the figure, 1: Print head 2 Nibraten 8: Paper feed table 9: Paper feed table lifting mechanism 14: Paper feed roller 18: Axis 19.27: Roller element 19a, 27a: Non-drive area 19c, 27c: Non-drive area Trailing edge 23: paper 24; slit disk 25: photoelectric sensor

Claims (1)

[Claims] A paper feed table (8), a paper feed roller (14) arranged above it
) and an elevating means (9) for increasing and narrowing the mutual distance between the paper feed table (8) and the paper feed roller (14), and the paper feed roller (14)
a plurality of roller elements (1) of equal diameter fixed to a shaft (18);
9, 27)..., each roller element (19, 27)... has a non-driving area (19a, 27a) on a part of its circumferential surface. and
The rear ends (19c, 27c) of this non-driving area are arranged so that the phases of the plurality of roller elements (19, 27) are sequentially shifted from those on one shaft end side to those on the other shaft end side. The non-driven areas of all roller elements (19a, 27
a) includes origin detection means (24, 25) for detecting the rotational position of the shaft (18) where the shaft (18) contacts the paper (23);
An automatic paper feeder characterized in that the elevating means (9) is operated in a direction in which the paper feed roller (14) and the paper feed table (8) approach each other at the detected rotational position.