JP2781693B2 - Paper feed mechanism for 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 feed mechanism for a printer, and more particularly to a mechanism for correcting skew of a sheet before printing.

[0002]

2. Description of the Related Art In a conventional paper feed mechanism, an operator inserts a paper so that the leading end of the paper is in direct contact with a contact position between a platen and a pressure roller so as not to be skewed, or a paper feed roller and a platen and a pressure roller are used. The leading edge of the sheet is brought into contact with the contact position of, and further feeding is performed until the sheet is curved, and the skew of the sheet is corrected by forcing the leading edge of the sheet parallel to the contact position of the platen and the pressure roller,
Next, the skew-corrected sheet was sent to the printing start position by the platen.

[0003]

SUMMARY OF THE INVENTION With these conventional techniques,
When inserting paper so that the operator does not skew,
The operator must pay close attention to skew every time a sheet is inserted, which is troublesome and poor in operability.

Further, when the paper is fed by the paper feed roller until the paper is curved, depending on the paper to be used, the leading end of the paper is bent without being curved due to forced paper feeding.
In addition to the skew correction, there was a possibility that a secondary obstacle might occur, such as uncertainty in sheet feeding by the platen.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a paper feed mechanism of a printer device which automatically corrects skew of arbitrarily inserted paper before printing.

[0006]

In order to achieve the above object, a sheet feeding mechanism of a printer according to the present invention comprises a sheet detecting means, a driving motor, a power transmission switching means, a pair of a sheet feeding roller and a pinch roller. And a roller spring. The paper feed mechanism of the printer device includes a platen and a pressure roller for holding the paper and feeding the paper by rotation of the platen. The paper detection means detects the paper inserted in the printer device. The drive motor is to detect
The power transmission switching means is for intermittently driving the driving force of the driving motor to the platen, and the paper feed roller and the pinch roller are inserted. The pinch roller receives the spring force of the roller spring and resiliently contacts the paper feed roller, and the roller spring moves between the platen and the pressure roller in a stopped state. The sheet has a spring force large enough to cause a slip between the sheet and the sheet feeding roller before the sheet is bent by the feeding of the sheet feeding roller in a state where the sheet is in contact with the abutting edge.

[0007]

The sheet is fed by a pair of a sheet feeding roller and a pinch roller to abut the edge of the butted platen and the pressure roller, which are in contact with each other. In this case, the spring force of the roller spring that presses the pinch roller against the paper feed roller is set to a size that does not cause the sheet to bend. When the sheet is skewed, the sheet is rotated by feeding the paper feed roller, and the skewed posture is corrected so that the leading edge of the sheet is parallel to the butted edges of the platen and the pressure roller.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing one embodiment of the present invention.

In FIG. 1, a platen 1 is rotatably installed at the end side of a paper guide 5, and a pressure roller 2 is elastically contacted with the platen 1 by a pressure spring 3 through a hole 5 a of the paper guide 5.

The print head 4 is arranged at a position in front of the platen 1 and is installed so as to be able to reciprocate in the length direction of the platen 1.

A pair of a paper feed roller 6 and a pinch roller 7 are installed at the start end side of the paper guide 5 through a hole 5b of the paper guide 5, and the pinch roller 7 is connected to the paper feed roller 6 by a roller spring 8. We are in pressure contact. A sheet detecting means 9 is provided adjacent to the sheet feeding roller 6.

The paper feed roller 6 is linked to a drive motor 11 via a gear train. The platen 1 and the drive motor 11 are linked via a power transmission switching unit 12, and the driving force of the drive motor 11 is intermittently connected to the platen 1 by the power transmission switching unit 12.

The roller spring 8 is adapted to feed the sheet to the sheet feeding roller 6 before the sheet is bent by the feeding of the sheet feeding roller 6 in a state where the sheet is in contact with the butted edge of the platen 1 and the pressure roller 2 in the stopped state. 6 has a spring force large enough to cause slippage.

In the embodiment, a pressure roller 2 is pressed against a platen 1 by a pressure spring 3 and is in contact at a position (abutting edge of the platen 1 and the pressure roller 2) P.

When it is detected from the direction of arrow A that the sheet 10a has been inserted by the sheet detecting means 9, the drive motor 11 rotates in synchronism therewith, and the power is transmitted to the sheet feeding roller 6, and the sheet 10a is moved to the position P. Transport to

A pinch roller 7 is pressed against the paper feed roller 6 by a spring 8. Here, the spring 8 is set to have a frictional force that causes the paper 10a to come into contact with the position P and to be squeezed with the paper feed roller 6 without being crushed even if the paper 10a is further fed.

The paper 10a is moved to the position P by the paper feed roller 6.
During contact with the platen, transmission of the power of the drive motor 11 to the platen is cut off by the power transmission switching means 12.

FIG. 2 and FIG. 3 are plan views for explaining the operation of the device of the present invention. Here, to simplify the drawing, the pressure spring 3, paper guide 5, spring 8, drive motor 11, and power transmission switching means 12 shown in FIG. 1 are omitted. Further, it can be seen that the paper feed roller 6 and the pinch roller 7 are arranged near the center in the paper width direction.

Referring to FIG. When the paper 10b is inserted up to the paper feed roller 6, the paper detection means 9 detects the paper insertion, the paper feed roller 6 rotates and feeds in the direction of arrow B, and the power of the drive motor 11 is changed by the power transmission switching means 12. It comes into contact with the position P where the cut platen 1 and the pressure roller 2 come into contact. At this time, when the sheet is inserted obliquely, the point N of the sheet 10c contacts the position P first.

Thereafter, as shown in FIG. 3, when the paper 10c is further fed by the paper feed roller 6, the paper 10c rotates in the direction of arrow C about the point N as the center of rotation, and the leading end of the paper 10d is parallel to the position P. It can be abutted to correct skew.

The sheet 10d abutted in parallel with the position P is
The power of the drive motor 11 shown in FIG.
The print head 4 is sent to a printing start position where the print head 4 is located.

As described above, by performing a series of sheet feeding operations in the order of FIG. 1, FIG. 2, and FIG. 3, the sheet 10a inserted at an arbitrary inclination into the printer is automatically corrected, and an appropriate It is possible to send to the print start position.

[0023]

As described above, according to the present invention, the abutting edge between the platen and the pressure roller in the stopped state is
The sheet in the skew state is brought into contact with the sheet, and the sheet is rotated by the feed of the sheet feeding roller to correct the skew.
If the paper is skewed, the paper skew can be automatically corrected before printing.

[Brief description of the drawings]

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

FIG. 2 is a plan view illustrating the operation of the device of the present invention.

FIG. 3 is a plan view illustrating the operation of the device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Platen 2 Pressure roller 3 Pressure spring 4 Print head 5 Paper guide 6 Feed roller 7 Pinch roller 8 Roller spring 9 Paper detection means 10a, 10b, 10c, 10d Paper 11 Drive motor 12 Power transmission switching means

Claims (1)

(57) [Claims] 1. A sheet detecting means, a drive motor, a power transmission switching means, a pair of a sheet feeding roller and a pinch roller, and a roller spring, wherein a sheet is clamped by a platen and a pressure roller. A paper feed mechanism of a printer device that feeds a paper by rotating the paper, wherein the paper detection means detects the paper inserted into the printer apparatus, and a drive motor is driven to rotate in synchronization with the paper detection of the paper detection means. The power transmission switching means is for intermittently driving the driving force of the driving motor to the platen, and the paper feed roller and the pinch roller are for conveying the inserted paper to the platen side. The pinch roller receives the spring force of the roller spring and resiliently contacts the sheet feeding roller. The roller spring is configured to stop the platen and the pressure roller. The paper has a spring force large enough to cause a slip between the paper and the paper feed roller before the paper is bent by the feeding of the paper feed roller in a state where the paper is in contact with the abutting edge of the paper. Paper feed mechanism of the printer device.