JPH06227072A - Paper feed mechanism - Google Patents

Abstract

PURPOSE:To provide a paper feed mechanism which can eliminate a dent and transfer to a medium such as pressure sensitive paper within a printing range, in relation to the paper feed mechanism of a printer. CONSTITUTION:In a paper feed mechanism provided with a plurality of rollers 14 which are arranged in a coaxial state, abut against a platen and convey a medium to be supplied, rollers 14 are provided in a pair so that they abut against a platen 11 on both the sides at the outside of a printing range.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art FIGS. 7A and 7B are schematic explanatory views of the structure of a conventional paper feeding mechanism (FIG. 7A is a front view and FIG. 7B is a side view), in which 1 is a platen and 2 is a pinch roller. 3 is a bail roller. A plurality of pinch rollers 2 and a plurality of bail rollers 3 are provided coaxially so as to come into contact with the platen 1 in the print area, and convey recording paper such as pressure-sensitive paper in the print area during paper feeding. The contact force of each roller with respect to the platen 1 is applied by a spring (not shown).

[0003]

In the above conventional structure, the paper is fed by the roller within the printing area, and the roller contact force with respect to the platen is adjusted by the spring. There is a limit, and when pressure sensitive paper or the like is used, for example, the roller causes the pressure marks 4a and the transfer 4b on the pressure sensitive paper.

It is an object of the present invention to provide a paper feeding mechanism capable of eliminating an indentation and a transfer to a medium such as a pressure sensitive paper in a printing area.

[0005]

In order to achieve the above object, according to the present invention, as shown in the principle diagram of FIG. 1, a plurality of units which are arranged coaxially and abut against a platen 11 to convey a medium to be supplied are conveyed. In a paper feed mechanism including individual rollers, the rollers are provided so as to contact the platen 11 on both sides outside the printing area (first configuration). In this figure, a pair of pinch rollers 14 and a pair of bail rollers 15 are shown.

[0006] Further, at least one pair of rollers arranged coaxially and abutting the platen 11 on both sides outside the printing region, and a single-cut medium rotatably supported by a shaft along the platen 11 and supplied. In a paper feeding mechanism of a printer including a pair of cut sheet guides 16 for guiding the sheet toward the platen 11, at least one of the rollers is provided with the cut sheet guide 1 on the side corresponding to the roller.
It is configured to open and close and move in conjunction with the rotation of 6 in the forward and reverse directions and the movement along the platen 11 (second configuration).

Further, a tractor for transporting the continuous form medium to be fed toward the platen is added to the paper feeding mechanism of the second structure, and the tractor is interlocked with the movement of the single-cut guide along the platen. The third configuration is characterized by being configured so as to move.

[0008]

Since the pair of rollers for conveying the medium abut on the platen 11 outside the printing area, the impression and transfer when using the pressure sensitive paper, which has been a problem in the past, are eliminated. In the case of the second configuration, it corresponds to the use of a plurality of types of single-cut media having different widths, and when the moving-side single-cut guide 16 is opened / closed and moved, one of the rollers can move. Since it opens and closes and moves in conjunction with each other, it is possible to cope with changes in the medium width.

Further, in the case of the third structure, when a tractor for conveying a continuous form medium is provided, it is possible to cope with a change in the width of the continuous form medium, and when the single-cut guide on one side is moved. , The tractor moves in conjunction with each other to respond to changes in the medium width. In this case, it goes without saying that the roller on one side also moves.

[0010]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 2 is a front view of the paper feeding mechanism of this embodiment, and FIG. 3 is a side view of the same. In FIG. 2, 11 is a platen and 12 is a paper feeding mechanism. The platen shaft 11a of the platen 11 is supported by the frame 13 of the apparatus. The paper feeding mechanism 12 is
A pinch roller 14, a bail roller 15, a single-cut guide 16, and a tractor 17 are provided, and a pair of these is provided corresponding to the left and right of the platen 11, respectively. Details of the configuration and operation of the paper feeding mechanism 12 are as follows.

The single-cut guide 16 is provided in parallel with the platen 11 and is supported by the frame 13 by a shaft 18A,
Can be rotated on shaft 18A of 18B (can be opened / closed)
The pin 16a, which is supported by the shaft 18A and is provided at one end of the pin 16a, is engaged with an elongated hole 19a formed in a main bracket 19 which is movably supported by the shafts 18A and 18B along the platen.

A pinch roller opening / closing bracket 20 is rotatably supported on the shaft 18A, and a round hole 20a at one end of the pinch roller opening / closing bracket 20 is engaged with the pin 16a. The pinch roller 14 is rotatably supported by the pin 16a, and the pinch roller 14 is in contact with the platen 11 by the urging force of a spring 21 urging the pinch roller opening / closing bracket 20. Teeth 20b are formed on the other end of the pinch roller opening / closing bracket 20.

A bail roller opening / closing bracket 22 having a tooth 22a meshing with a tooth 20b formed at one end is rotatably supported on the main bracket 19 via a pin 23, and the other end of the bail roller opening / closing bracket 22 is connected to the bail roller bracket. It faces the flange 24 a of 24. The bail roller bracket 24 rotatably supports the bail roller 15, and is supported by a pin 25 and rotatable.

The bail roller bracket 24 is biased by a spring 26, and the bail roller 15 is in contact with the platen 11 by this biasing force. When the pinch roller 14 and the bail roller 15 are in contact with the platen 11 in this manner, the single-cut guide 16 guides the single-cut medium to the platen 1.
The single-cut medium, which is in a position to be guided toward 1, is guided by the single-cut guide 16 to the side and supplied, is the platen 11
And the pinch roller 14 and the bail roller 15 which are pressed against this
It is transported by.

When the continuous form medium is used, the continuous form medium is set to the platen 1
FIG. 4 shows a fixing structure of the tractor 17 that conveys the tractor 17 toward the first position. The tractor 17 is shown in FIG.
Further, as shown in FIG. 4B which is a sectional view taken along line BB of FIG. 3, the tractor fixing stud 27 fixes the main bracket 19 and is movable together with the main bracket 19 guided by the shafts 18 and 18B. The tractor drive shaft 28 is an extension of the shaft 18B.

The drive system for the tractor 17 and the platen 11 is as shown in FIG. 5, and these are driven by a common drive motor 29 by the illustrated gear system. In FIG. 5, 3
Reference numeral 0 is a carrier which is guided by the guide shaft 31 and is movable along the platen 11, and 32 is a print head mounted on the carrier 30.

The medium 1 of the paper feeding mechanism 12 having such a structure
00 (see FIG. 2), the left and right paper feeding mechanisms 12 are positioned at the positions where the rollers 14 and 15 come into contact with each other on both sides of the medium to be set outside the printing area in the following procedure. When the position of the paper feeding mechanism 12 on one side is fixed and the paper feeding mechanism 12 on the other side is positioned according to the medium width, the other paper feeding mechanism 12 is positioned.
Move only the position of.

FIG. 6 is an explanatory view of the operation of the paper feeding mechanism of this example (FIG. 6A shows each roller open state, and FIG. 6B shows each roller closed state similar to FIG. 3). At the time of positioning, move the single-cut guide 16 from the state of FIG.
Rotate a predetermined amount in the direction. As a result, the pinch roller opening / closing bracket 20 engaging with the single-cut guide 16 via the pin 16a rotates in the direction of arrow D against the urging force of the spring 21 by a predetermined amount, and the pinch roller 14 is shown in FIG. 6 (A). To be opened. At this time, the pin 16a has an elongated hole 19a (see FIG.
(See) Move in.

At the same time, the pinch roller opening / closing bracket 20
The bail roller opening / closing bracket 22, which engages with the teeth via teeth 20b and 22a, rotates in the direction of arrow E in FIG. 6B by a predetermined amount. During this rotation, the bail roller opening / closing bracket 2
The other end of 2 is the flange 24 of the bail roller bracket 24.
By engaging with a, the bail roller bracket 24 is rotated in the direction of arrow F in FIG. 6B against the biasing force of the spring 26. As a result, the bail roller 15 is opened as shown in FIG.

When the single-cut guide 16 is moved in the predetermined direction along the platen 11 with the rollers 14 and 15 opened as described above, the tractor 17, the main bracket 19, the pinch roller opening / closing bracket 20, The bail roller opening / closing bracket 22 also moves in conjunction with each other, and each of the rollers 14 and 15 reaches a predetermined position (a position facing the end of the medium to be set outside the printing area). When the cut sheet guide 16 is rotated to its original position, the rollers 14 and 1 are rotated.
5 is closed as shown in FIG. 6 (B), and the positioning of the feed mechanism 12 is completed.

In this state of positioning, the fed single-cut sheet medium is guided and fed and conveyed by the single-cut sheet guide 16, and the continuous form medium fed by the tractor 17 is guided by the conveyance guide 33.

As described above, in this example, each roller 14,
Since the paper feed mechanism can be positioned so that 15 is in contact with both sides of the medium outside the printing area, it is possible to eliminate the impression and transfer when using pressure sensitive paper, which has been a problem in the past.

The paper feeding mechanism 1 positioned as described above
The printing on the medium conveyed by 2 is performed by the platen 11
This is done by operating the print head 32 on the carrier 30 which moves along with the print head 32 at a predetermined time and in a predetermined pattern.

[0025]

As described above, according to the present invention, the paper can be fed at the left and right ends of the medium outside the printing area, so that it is possible to prevent the impression and transfer of the pressure-sensitive paper in the printing area. Become. Further, by rotating and moving the single-cut guide, the rollers and the tractor can be positioned at desired positions.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a front view of the paper feeding mechanism according to the embodiment of the invention.

FIG. 3 is a side view of the paper feeding mechanism of the embodiment of the present invention.

4A and 4B are explanatory views of a fixing structure of a tractor according to an embodiment of the present invention, FIG. 4A is a view taken in the direction of arrow A in FIG. 3, and FIG. 4B is a sectional view taken along line BB in FIG.

FIG. 5 is an explanatory diagram of a drive system for a tractor and a platen according to an embodiment of the present invention.

FIG. 6 is an operation explanatory view of the paper feeding mechanism of the embodiment of the present invention,
FIG. 6A shows each roller open state, and FIG. 6B shows each roller closed state.

FIG. 7 is a schematic diagram illustrating the structure of a conventional paper feeding mechanism.
7A is a front view, and FIG. 7B is a side view.

[Explanation of symbols]

 11 Platen 12 Paper Feed Mechanism 14 Pinch Roller (Roller) 15 Bail Roller (Roller) 16 Cut Sheet Guide 17 Tractor

Claims (3)

[Claims] 1. A coaxially arranged abutting platen,
In a paper feeding mechanism of a printer including a plurality of rollers for feeding a medium to be supplied, at least one pair of the rollers is provided so as to contact the platen on both sides outside a printing area. Feeding mechanism. 2. A pair of rollers arranged coaxially and abutting both sides of the platen outside the printing area, and rotatably supported by a shaft along the platen.
In a paper feed mechanism of a pretan provided with a pair of cut sheet guides for guiding a supplied cut sheet medium toward the platen on both sides, at least one of the rollers is provided on a side corresponding to the roller. A paper feeding mechanism configured to open and close and move in association with forward and reverse rotations of the cut sheet guide and movement along the platen. 3. The paper feed mechanism according to claim 2, further comprising a tractor for feeding the continuous form medium supplied to the platen, the tractor interlocking with the movement of the single-cut guide along the platen. A paper feed mechanism characterized in that it is configured to move as it moves.