JPH11286147A - Perfecting mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform printing simultaneously on the surface and read of a thermal sheet by disposing a first print section comprising a first line thermal head and a platen roller symmetrically to a second print section comprising a second line thermal head and a platen roller. SOLUTION: When an LF motor is turned in a predetermined direction based on a drive command of a sheet carrying system, feed rollers 11, 21 and platen rollers 13, 23 are turned synchronuously through a plurality of sets of gear train. Consequently, a thermal sheet is carried between a line thermal head 12 and a platen roller 13 at a first print section 10 and printing is performed on the surface side thereof. Subsequently, the thermal sheet is carried between a line thermal head 22 and a platen roller 23 at a second print section 20 disposed symmetrically to the line thermal head 12 with respect to the thermal sheet carrying path and printing is performed on the rear side of the thermal sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-sided printing mechanism, and more particularly to a two-sided printing mechanism for simultaneously printing both sides of a thermal paper using a line thermal head.

[0002]

2. Description of the Related Art A conventional double-sided printing mechanism will be described in detail with reference to the drawings.

FIG. 4 is a side view showing an example of the prior art. The two-sided printing mechanism shown in FIG. 4 includes a printing unit 1 arranged on both sides of the path of the sheet P conveyed by the sheet feeding units 110 and 111.
20 and 130 (see, for example,
-51149 gazette).

[0004] The printing means 120 and 130 are provided with carriers 121 and 131 which reciprocate in parallel with the plane of the paper P.
have. Carriers 121 and 131 have thermal heads 122 and 132 and motors 123 and 133 for self-propelling.
Are provided. Running gears 124 and 134 are attached to the motors 123 and 133.

On the other hand, carriers 125, 131 are provided in frames 125, 135 of printing means 120, 130, respectively.
Shaft 1 for guiding the paper in parallel with the paper surface of the paper P
26, 136, racks 127, 137 with which the running gears 124, 134 mesh, and platens 128, 138 are provided.

[0006] An ink ribbon is installed on the carriers 121 and 131, and the motors 123 and 133 are rotated forward or backward, and the carriers 121 and 131 are reciprocated to give print commands to the thermal heads 122 and 132, thereby enabling double-sided printing. Done.

[0007]

The above-described conventional double-sided printing mechanism has a drawback that it has a large size and a low printing speed because there are many mechanical parts such as a frame on which a platen is mounted.

[0008]

According to a first aspect of the present invention, a double-sided printing mechanism includes a first printing unit having a first line thermal head and a first platen roller sandwiching a paper transport path; The second line thermal head and the second printing unit having the second platen roller are arranged symmetrically with each other, and printing is performed simultaneously on the front and back surfaces of the thermal paper.

A double-sided printing mechanism according to a second aspect of the present invention is the double-sided printing mechanism according to the first aspect, wherein the first and second feed rollers and the first and second feed rollers are fed from an LF motor driving source fixed to a frame for transporting the thermal paper. A gear mechanism for transmitting rotation to the first and second platen rollers, a first gear fixed to the first and second feed rollers, and a second gear fixed to the first and second platen rollers.

According to a third aspect of the invention, in the double-sided printing mechanism according to the first aspect, the first and second printing units are configured such that the first and second thermal heads and the first and second platen rollers face each other. In contrast to the arrangement of the line thermal head and the platen roller of the first printing unit for printing on the front side of the thermal paper, the line thermal head and the platen roller of the second printing unit for printing on the back side of the thermal paper are symmetrical to each other. Are located.

A double-sided printing mechanism according to a fourth aspect of the present invention is the first aspect, wherein the first and second plates for detecting the thermal paper before the first and second platen rollers and transporting the thermal paper to a printable position are provided. A sensor is provided.

A double-sided printing mechanism according to a fifth aspect of the present invention is the double-sided printing mechanism according to the first aspect, wherein the thermal paper is conveyed by a first foot roller, and the first sensor detects the leading end of the thermal paper, and
The thermal paper is sent to a position where printing is possible between the line thermal head and the first platen roller, and printing is performed on the front side of the thermal paper by a print command to the first line thermal head.

According to a sixth aspect of the present invention, in the first aspect of the present invention, when a certain amount of thermal paper is sent from the first printing unit, the leading end of the thermal paper is detected by the second sensor. The thermal paper is sent to a position where printing can be performed between the second line thermal head and the second platen roller symmetrically arranged with the line thermal head. Print on the back side.

A double-sided printing mechanism according to a seventh aspect of the present invention is the double-sided printing mechanism according to the first aspect, wherein the first and second inks pass between the first and second line thermal heads and the first and second platen rollers. The first and second ribbons are synchronized with the transport speed of the paper.
Means for feeding the ink ribbon in each direction;
And means for simultaneously thermally transferring the ink applied on the printing surface side of the second ink ribbon to both sides of the paper.

[0015]

Next, the present invention will be described in detail with reference to the drawings. 1A to 1C are a side view and a plan view showing one embodiment of the present invention. FIG. 2 shows FIG.
FIG. 4 is a side view showing details of a printing unit shown in FIG.

The double-sided printing mechanism shown in FIGS. 1 (a) to 1 (c)
Printing unit 10 having a first platen roller 13 and a first printing unit 10
And the second line thermal head 22
Printing section 20 having a second platen roller 23 and a second printing section 20
Are arranged symmetrically with each other, and printing is performed simultaneously on the front and back surfaces of the thermal paper 1.

The double-sided printing mechanism of the present invention comprises a feed roller 11, 21 and a platen roller 1 from a drive source of an LF motor 3 fixed to a frame 2 for transporting a thermal paper 1.
Gears (11) 6 and gears (12) 7 for transmitting rotation to gears 3 and 23, gear (F) 5 fixed to feed rollers 11 and 21, and gear (P) fixed to platen rollers 13 and 23. ) 4 is provided.

In the printing units 10 and 20, line thermal heads 12 and 22 and platen rollers 13 and 23 face each other.
In contrast to the arrangement of the line thermal head 12 and the platen roller 13 of the printing unit 10 for printing on the front side of the thermal paper 1, the line thermal head 22 and the platen roller 23 of the printing unit 20 for printing on the back side of the thermal paper 1 are symmetrical to each other. Are located in

Further, sensors 14 and 24 are provided in front of the platen rollers 13 and 23 for detecting the thermal paper 1 and transporting the thermal paper 1 to a printable position.

Next, the operation will be described. The LF motor 3 rotates in a certain direction according to a drive command of the paper transport system. By driving the LF motor 3, the respective gears are connected, and the feed rollers 11, 21 and the platen rollers 13, 23
The rotation is transmitted to.

The thermal paper 1 conveyed by the driving of the LF motor 3 is sent to printing sections 10 and 20 where printing can be performed by feed rollers 11 and 21, and is printed on both front and back sides of the thermal paper 1.

First, the thermal paper 1 is conveyed by the feed roller 11, the leading end of the thermal paper 1 is detected by the sensor 14, and the thermal paper 1 is moved to a position where printing can be performed between the line thermal head 12 and the platen roller 13. The printing is performed on the front side of the thermal paper 1 by a print command to the line thermal head 12.

Next, a certain amount of heat-sensitive paper 1
Is sent, the leading end of the thermal paper 1 is detected by the sensor 24, and the thermal paper 1 is sent to a position where the thermal paper 1 can be printed between the line thermal head 22 and the platen roller 23 symmetrically arranged with the line thermal head 12, Printing is performed on the back side of the thermal paper 1 by a print command to the line thermal head 22.

The double-sided printing mechanism of the present invention can simultaneously print on both the front and back surfaces of the thermal paper by unidirectional transport of the thermal paper.

FIG. 3 is a side view showing a second embodiment of the present invention. The two-sided printing mechanism shown in FIG. 3 includes ink ribbons 9-a and 9-b passing between the line thermal heads 12 and 22 and platen rollers 13 and 23, and the ink ribbons 9 in synchronization with the transport speed of the paper 8. Means for feeding the ink ribbons 9-a and 9-b in the directions of the respective arrows;
-B means for simultaneously thermally transferring the ink applied to the printing surface side to both sides of the paper 8.

The printing section can be miniaturized because it is composed only of the parts facing the line thermal head and the platen roller, and the printing speed is improved because the line thermal head is used.

[0027]

According to the double-sided printing mechanism of the present invention, since the paper runs only in one direction between a pair of line thermal heads arranged opposite to each other, there is an effect that the printing speed can be reduced in size.

[Brief description of the drawings]

FIGS. 1A to 1C are a side view and a plan view showing a first embodiment of the present invention.

FIG. 2 is a side view showing details of FIG. 1;

FIG. 3 is a side view showing a second embodiment of the present invention.

FIG. 4 is a side view showing an example of the related art.

[Explanation of symbols]

 1 paper 2 frame 3,5 LF motor 4,7 gear 8 paper 9a, 9b ink ribbon 10,20 printing unit 11,21 feed roller 12,22 line thermal head 13,23 platen roller 14,24 sensor

Claims (8)

[Claims] 1. A first printing section having a first line thermal head and a first platen roller sandwiching a paper transport path, and having a second line thermal head and a second platen roller sandwiching a paper transport path. A double-sided printing mechanism wherein the second printing unit and the second printing unit are arranged symmetrically with respect to each other, and printing is performed simultaneously on both sides of the thermal paper. 2. A gear mechanism for transmitting rotation to a first and second feed roller and a first and second platen roller from an LF motor driving source fixed to a frame for transporting the thermal paper, and 2. The double-sided printing mechanism according to claim 1, further comprising a first gear fixed to the first and second feed rollers, and a second gear fixed to the first and second platen rollers. 3. A first printing section for printing on the front side of thermal paper, wherein the first and second printing sections face the first and second thermal heads and the first and second platen rollers. 2. The double-sided printing mechanism according to claim 1, wherein the line thermal head and the platen roller of the second printing unit for printing on the back side of the thermal paper are arranged symmetrically with respect to the arrangement of the line thermal head and the platen roller. 4. A double-sided printing mechanism according to claim 1, further comprising a first sensor and a second sensor for detecting the thermal paper and transporting the thermal paper to a printable position before the first and second platen rollers. . 5. A thermal paper is conveyed by a first feed roller, and a first sensor detects a leading end of the thermal paper,
2. The thermal paper is sent to a position where printing is possible between the first line thermal head and the first platen roller, and printing is performed on the front side of the thermal paper by a print command to the first line thermal head. Double-sided printing mechanism. 6. When a certain amount of thermal paper is fed from the first printing unit, the leading end of the thermal paper is detected by a second sensor, and a second line disposed symmetrically with the first line thermal head. 2. The double-sided printing mechanism according to claim 1, wherein the thermal paper is sent to a position where printing is possible between the thermal head and the second platen roller, and printing is performed on the back side of the thermal paper by a print command to the second line thermal head. 7. The double-sided printing mechanism according to claim 1, wherein printing is performed simultaneously on the front and back surfaces of the thermal paper by one-way transport of the thermal paper. 8. A first and a second plate passing between a first and a second line thermal head and a first and a second platen roller.
Means for feeding the first and second ink ribbons in each direction in synchronization with the paper transport speed;
2. A double-sided printing mechanism according to claim 1, further comprising: means for thermally transferring the ink applied to the printing surface side of the first and second ink ribbons to both sides of the paper simultaneously.