JP2643616B2 - Paper feeder such as printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeding device such as a printer.

[0002]

2. Description of the Related Art FIG. 6 is a schematic side view showing a paper feeding device of a conventional printer. In FIG. 6, reference numeral 1 denotes a paper cassette, 2 denotes paper, and 3 denotes a paper feed roller for separating the uppermost one of the paper 2. 4 is a paper feed roller, 5, 6, and 7 are paper guides,
8, 9 are pinch rollers, 10 is a platen roller, 11 is a thermal head, 12 is an ink sheet, 13 is a sheet leading edge detection sensor, and a sheet 2 fed from the sheet cassette 1
Is to be guided by the paper guides 5 and 6 by the paper feed roller 4 and to detect the leading end of the paper 2 wound around the platen roller 10.

Next, the operation will be described. Paper feed roller 3
The paper 2 separated from the paper cassette 1 is guided by the paper guide 5 and reaches the paper feed roller 4, and is guided by the paper feed rollers 4 to the paper guides 5 and 6,
It is sent to the pressure contact between the platen roller 10 and the pinch roller 9. At this time, in order to minimize the printing deviation, the paper path formed by the paper guides 5 and 6 for guiding the paper 2 to the platen roller 10 is narrowed as much as possible. Guided to 10. Further, the paper 2 is fed along the thermal head 11, passes through the pressure contact between the platen roller 10 and the pinch roller 8, reaches the paper leading edge detection sensor 13 added to the paper guide 7, and detects the leading edge of the paper. . At this time, the paper 2 is also restrained by the paper feed roller 4. The sheet 2 wound around the platen roller 10 via the pinch rollers 8 and 9 is sent by the driving force of the platen roller 10, and the sheet 2 is pressed against the pinch roller 8 and the platen roller 10 in order to expand the printing area. Printing is started after the sheet 2 is reversed by rotating the platen roller 10 in the reverse direction for a certain amount that does not deviate from the point (this is referred to as sheet leading operation).

[0004]

Since the conventional paper feeding device of the printer is constructed as described above, when the paper 2 is reversely fed, a gear system (which drives the platen roller 10 and the paper feeding roller 4). (Not shown) and backlash of each roller shaft and gear are accumulated,
A difference occurs in the sheet feed amount between the platen roller 10 and the sheet feed roller 4. Further, since the paper guide 5 guides the paper 2 so as to be in close contact in order to reduce the printing deviation, there is no place for the difference in the above-mentioned paper feed amount at the time of reverse feeding of the paper, which causes a paper jam. .

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a stable paper feeder such as a printer which can reduce a printing deviation and hardly cause a paper jam. It is a further object of the present invention to provide a paper feeding device such as a printer in which the occurrence of the paper jam does not depend on the accuracy of the completed paper feeding system.

[0006]

A paper feeding device such as a printer according to the present invention has a paper guide provided with a concave portion.

[0007]

In the paper feeding device such as a printer according to the present invention, the concave portion provided in the paper guide absorbs the slack of the paper which causes the paper jam.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic side view, FIG. 2 is a perspective view showing the paper guide of FIG. 1, and FIGS. 3 to 5 are views for explaining the operation. The description is omitted. In the drawing, reference numeral 14 denotes a concave portion provided in the paper guide 5, which absorbs the slack of the paper 2 at the time of reverse feeding of the paper. The paper guide 5 is provided with a paper running rib 5a and a paper restraining rib 5b.

Next, the operation will be described. The paper 2 fed by the paper feed roller 4 is connected to the paper running rib 5 by the paper restraining rib 5b of the paper guide 5 in order to reduce the printing deviation.
a (highly convex) than the platen roller 1 along the paper guide 5 while keeping the paper 2 in close contact with the paper restraining rib 5b.
Guided to 0. FIG. 4 shows a state in which the leading end of the sheet 2 thus fed reaches the leading end detection sensor 13.
In this state, the platen roller 10 and the sheet feed roller 4 rotate in reverse to back the sheet 2, and the slack of the sheet 2 due to the difference in the sheet feed amount between the platen roller 10 and the sheet feed roller 4 is reduced by the sheet guide 5 as shown in FIG. The sheet is absorbed by the concave portion 14 provided in the printer, and the sheet feeding is completed, and printing starts.

[0010]

As described above, according to the present invention, since the concave portion is provided in the paper guide, paper jam is less likely to occur.
There is an effect that a stable paper feeder can be obtained. Also,
There is also an effect that the occurrence of a jam becomes less dependent on the accuracy of the completion of the paper feeding system, and the apparatus can be inexpensive.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing one embodiment of the present invention.

FIG. 2 is a perspective view showing the paper guide of FIG. 1;

FIG. 3 is an explanatory diagram illustrating a middle of sheet feeding in FIG. 1;

FIG. 4 is an explanatory diagram illustrating a state in which a sheet leading edge detection sensor captures a sheet leading edge.

FIG. 5 is an explanatory diagram showing a state in which a sheet is fed backward from the state of FIG. 4;

FIG. 6 is a schematic side view showing a conventional device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 paper cassette 2 paper 3 paper feed roller 4 paper feed roller 5,6,7 paper guide 8,9 pinch roller 10 platen roller 11 thermal head 12 ink sheet 13 paper leading edge detection sensor 14 recess

Claims (1)

(57) [Claims] A sheet feed roller for separating the uppermost sheet of the sheets stored in a sheet cassette from the sheets located below the sheet cassette;
A paper feed roller that sends the separated paper to the platen roller
Roller from the paper feed roller and the platen roller
And a curved paper guide for guiding to over La, one
Paper between the paper feed roller and the platen roller
In a paper feeding device such as a printer that conveys the paper in a held state, a part of the paper guide expands outwardly from the curved surface.
A paper feeding device such as a printer, wherein a paper recess is provided.