JP3189595B2 - Image printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image printer which uses a capstan roller and a pinch roller to transport recording paper during recording.

[0002]

2. Description of the Related Art In recent years, some image printers have been pursued to pursue miniaturization and cost reduction of apparatuses while pursuing high quality and high quality recording on special recording paper. Was.

Hereinafter, an example of the above-described conventional image printer will be described with reference to the drawings. FIG. 3 is a sectional view of a conventional image printer. In FIG.
Reference numeral 4 denotes an apparatus main body having a recording unit including a thermal head 1, a platen 2, and an ink sheet 3, reference numeral 8 denotes a rotatable pickup roller, reference numeral 7 denotes a separate roller rotatably provided like the pickup roller 8, and reference numeral 16 denotes a separate roller 7. The pickup roller 8, the separate roller 7, and the reverse roller 16 form a sheet feeding device for the sheet-like recording paper 12. Reference numeral 11 denotes a recording paper cassette which accommodates the recording paper 12 and is slidable and detachable on a cassette guide portion 18 of the apparatus main body 14, 13 denotes a lifting unit for pressing the recording paper 12 against the pickup roller 8, and 10 denotes a recording paper. Cassette 1
1 is a recording paper push-up plate which presses the recording paper 12 while being loaded by the elevating unit 13; 6 is a switching guide for switching between paper feeding and paper discharging; 15 is a guide member for guiding the recording paper 12; Reference numeral 5 denotes a pinch roller and a capstan roller which are driven after feeding the recording paper. Reference numerals 21 and 20 denote a discharge roller for discharging the recording paper 12 and a discharge pinch roller. 9 is a paper detection sensor for detecting the recording paper 12, 24
Is an IC cover attached to the thermal head 1 for guiding the ink sheet 3 and the recording paper 12 and protecting the IC of the thermal head 1, 26 is an ink sheet cassette around which the ink sheet 3 is wound, and 17 is an ink sheet cassette 26
An ink sheet cassette guide 19 for holding the recording paper 12 and guiding the recording paper 12; 19, a curved surface guide member for greatly changing the conveying direction of the recording paper 12; A sub-curved surface guide member is provided, and 27 is a bottom surface guide member. Reference numeral 25 denotes a fan motor for cooling the thermal head 1.

The operation of the conventional image printer configured as described above will be described below.

First, in FIG. 3, a recording paper cassette 11 containing a plurality of recording papers 12 is mounted along a cassette guide section 18 of a main body 14 of the apparatus. When the paper is fed, the elevating unit 13 rises to push up the recording paper push-up plate 10, presses the recording paper 12 on the recording paper push-up plate 10 against the pickup roller 8, and rotates the pickup roller 8 to rotate the recording paper 12. Conveyed. On the other hand, the reverse roller 16 that has been separated from the separation roller 7 rotates and presses the separation roller 7, and rotates in the reverse direction with respect to the paper feeding direction. If the above is the case, a sheet feeding means for separating the second and subsequent sheets is formed. The conveyed sheet of recording paper 12 is guided by the guide member 15 and the switching guide 6, conveyed by a predetermined amount after the recording paper 12 is detected by the paper detection sensor 9, and passes between the capstan roller 5 and the pinch roller 4. When the paper feeding operation is completed, the recording paper 12 is moved by the arrow A by pressing and rotating the capstan roller 5 and the pinch roller 4.
Conveyed in the direction. The recording paper 12 is guided obliquely downward by the rising IC cover 24 of the thermal head 1 except during recording, passes between the bottom guide member 27 and the ink cassette guide 17, and finally has the curved guide member 19.
Along the sub-curved surface guide member 22 so that the conveyance direction is largely bent upward.

Here, the end of the recording paper 12 passes through the switching guide 6, is detected by the paper detection sensor 15, and thereafter the thermal head 1 descends and is pressed by the platen roller 2, so that the recording operation in the recording unit is started. Begin. The recording paper 12 has an arrow B
After passing through the upper side of the switching guide 6 and the paper guide portion opposing the switching guide 6, the paper passes between the paper discharge roller 20 and the paper discharge pinch roller 21. After recording of one color, the thermal head 1 rises, and the end of the recording paper 12 reaches the paper detection sensor 15.
The recording paper 12 is pulled back in the direction of arrow A until the recording paper 12 is detected.

In the case of full-color printing, three colors of YMC are usually recorded. Therefore, the above operation is repeated three times. After the recording operation is completed, the recording paper 12 is driven by driving the paper discharge roller 20 and the paper discharge pinch roller 21. The sheet is discharged in the direction of arrow B.

[0008]

In the above configuration, however, the paper transport in the non-pressed state of the thermal head is light in load and causes no problem. When a large load is generated, a frictional load is also generated between the curved paper guide member and the sub-curved surface guide member and the recording paper, and the resultant force exceeds the recording paper conveyance force of the capstan roller / pinch roller. However, there has been a problem that color misregistration occurs, and a sliding scratch occurs on the recording paper by the curved guide member on the printing screen side. Further, in order to increase the recording paper conveyance force, the pressing force of the capstan roller and the pinch roller is increased, and as a result, the torque of the capstan drive motor is increased, which leads to an increase in cost and an increase in the size of the apparatus. Had problems.

An object of the present invention is to solve the above-mentioned problems and to provide a small-sized and low-cost image printer free from color misregistration and printed image flaws.

[0010]

In order to achieve this object, an image printer according to the present invention comprises a paper feeding means for feeding sheet-shaped recording paper, a capstan roller for feeding the recording paper after feeding, and a pinch. Paper transport means comprising rollers, thermal head for performing thermal transfer recording on recording paper, recording means comprising an ink sheet and a platen, and curved paper guide means for changing the recording paper transport direction to the downstream side of the recording paper transport of the recording means And the recording paper has a wrap angle of angle θ on the opposite surface of the paper guide.
Followed with recording paper due to wrap and recording paper conveyance sliding load
And a rotatable guide roller means.

[0011]

According to the present invention, with the above-described structure , the
The increase in the load will mainly be caused by head pressing at the time of recording, since the guide roller means is driven to rotate together with the recording paper, have a large sliding frictional force conventionally generated between the fixed sub-curved guide member and the recording sheet and whereas, to occur on the shaft of the guide roller means that Do a load of small rolling friction. Therefore, the recording paper conveying force required for the capstan roller and the pinch roller is smaller than in the conventional art, and color shift and sliding scratches on the recording paper do not occur. Further, in order to be able to reduce the recording paper conveying force, it is possible to reduce the pressing force of the capstan roller and the pinch roller, size and cost of the drive motor so Ru can be reduced torque of the capstan drive motor as a result In
Easy to use, the recording paper transport path can be downsized in the longitudinal direction.
With a simple configuration, the size of the apparatus can be reduced at low cost.

[0012]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a front sectional view of an image printer according to the present embodiment. FIG. 2 is a perspective view of main components in the present embodiment.

In FIG. 1, reference numeral 14 denotes a thermal head 1;
An apparatus main body having a recording unit composed of a platen 2 and an ink sheet 3; a rotatable pickup roller 8;
Is a reverse roller rotatably provided like the pickup roller 8, 16 is a reverse roller that can be pressed against the separate roller 7 and can rotate in the reverse direction, and the pickup roller 8, the separate roller 7, and the reverse roller 16 are sheet-like recording paper 12 Is formed. 11 is the recording paper 1
2, a recording paper cassette slidably and detachably mounted on a cassette guide section 18 of the apparatus main body 14, a lifting section 13 for pressing the recording paper 12 against the pickup roller 8, and a mounting section 10 for the recording paper cassette 11. A recording paper push-up plate which is pressed by the elevating unit 13 while loading the recording paper 12, 6 is a switching guide for switching between paper feeding and paper discharging, 15 is a guide member for guiding the recording paper 12, 4, 5,
Denotes a pinch roller and a capstan roller which are driven after the recording paper is fed. Reference numerals 21 and 20 denote a discharge roller for discharging the recording paper 12 and a discharge pinch roller. 9 is a paper detection sensor for detecting the recording paper 12, 24 is an IC cover attached to the thermal head 1 for guiding the ink sheet 3 and the recording paper 12 and protecting the IC of the thermal head 1.
Reference numeral 6 denotes an ink sheet cassette around which the ink sheet 3 is wound, and reference numeral 17 denotes an ink sheet cassette guide that holds the ink sheet cassette 26 and guides the recording paper 12. In FIGS. 1 and 2, reference numeral 19 denotes a curved guide member which largely changes the conveyance direction of the recording paper 12, 23 denotes a guide roller member having a gap corresponding to at least several paper thicknesses at an opposing portion of the curved guide member 19, and 27 denotes a guide roller member. It is a bottom guide member. 2
Reference numeral 5 denotes a fan motor for cooling the thermal head 1.

The operation of the image printer having the above-described configuration according to the present embodiment will be described below.

First, in FIG. 1, a recording paper cassette 11 containing a plurality of recording papers 12 is mounted along a cassette guide section 18 of a main body 14 of the apparatus. When the paper is fed, the elevating unit 13 rises to push up the recording paper push-up plate 10, presses the recording paper 12 on the recording paper push-up plate 10 against the pickup roller 8, and rotates the pickup roller 8 to rotate the recording paper 12. Conveyed. On the other hand, the reverse roller 16 that has been separated from the separation roller 7 rotates and presses the separation roller 7, and rotates in the reverse direction with respect to the paper feeding direction. If the above is the case, a sheet feeding means for separating the second and subsequent sheets is formed. The conveyed sheet of recording paper 12 is guided by the guide member 15 and the switching guide 6, conveyed by a predetermined amount after the recording paper 12 is detected by the paper detection sensor 9, and passes between the capstan roller 5 and the pinch roller 4. When the paper feeding operation is completed, the recording paper 12 is moved by the arrow A by pressing and rotating the capstan roller 5 and the pinch roller 4.
Conveyed in the direction. The recording paper 12 is guided obliquely downward by the rising IC cover 24 of the thermal head 1 except during recording, passes between the bottom guide member 26 and the ink cassette guide 17, and then to FIG. 1 and FIG. As shown in the figure, the conveyance direction is largely bent upward along the curved surface guide member 19 and the guide roller member 23. A load is applied to the curved guide member 19 and the back surface of the recording paper 12 by a sliding frictional force, but the front surface (printed screen) of the recording paper 12 is wound around the guide roller member 23 by an angle θ, but slides due to co-rotation. The load is a frictional load generated in the bearing portion of the guide roller member 23, and is sufficiently small as compared with the related art.

Here, the end of the recording paper 12 passes through the switching guide 6, is detected by the paper detection sensor 15, and thereafter the thermal head 1 is lowered and pressed by the platen roller 2, so that the recording operation in the recording unit is started. Begin. The recording paper 12 has an arrow B
After passing through the upper side of the switching guide 6 and the paper guide portion opposing the switching guide 6, the paper passes between the paper discharge roller 20 and the paper discharge pinch roller 21. Since the recording paper 12 is conveyed in the direction of arrow B, the load due to the pressing of the thermal head 1 and the platen 2, the load due to the sliding frictional force between the curved guide member 19 and the recording paper 12, and the guide roller member 23 that is smaller than in the related art. A friction load occurs in the bearing.

After recording of one color, the thermal head 1 is raised, and the recording paper 12 is pulled back in the direction of arrow A until the end of the recording paper 12 is detected by the paper detection sensor 15.

In the case of full-color recording, three colors of YMC are usually recorded. Therefore, the above operation is repeated three times. After the recording operation is completed, the recording paper 12 is driven by the discharge roller 20 and the discharge pinch roller 21 to drive the recording paper 12. The sheet is discharged in the direction of arrow B.

The guide roller member 23 is desirably of a left-right symmetric type with respect to the running direction of the recording paper 12 from the viewpoint of running stability. Further, when the cooling fan motor 25 is sandwiched between the pair of shapes, the size of the device can be further reduced. In addition, as the winding angle θ of the recording paper 12 is larger, the effect of reducing the load on the guide roller member 23 and the effect of reducing the scratches are greater as compared with the curved surface sub-guide member.

[0021]

As described above, the image printer of the present invention has the following advantages .
Paper feed means for feeding sheet-like recording paper, paper conveyance means consisting of a capstan roller and pinch roller for conveying the recording paper after feeding, and a thermal head, ink sheet, and platen for performing thermal transfer recording on the recording paper and comprising a recording unit, and a curved paper guide means for changing the conveying direction of the recording paper to the recording paper conveyance downstream side of the recording means,-out with winding the recording sheet to the pair facing surfaces of the paper guide with a winding angle of the angle θ In addition, the conveyance of the recording paper
By providing a driven rotatable guide roller means together with the recording sheet in the rolling, without the occurrence of color shift or slide print surface scratches caused by the increase in frictional load with a simple configuration, reduce the size of the device at a low cost An excellent image printer can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an image printer according to an embodiment of the present invention.

FIG. 2 is a perspective view of main components in one embodiment of the present invention.

FIG. 3 is a sectional view of a conventional image printer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermal head 2 Platen 3 Ink sheet 4 Pinch roller 5 Capstan roller 7 Separate roller 8 Pickup roller 12 Recording paper 14 Main body 16 Reverse roller 19 Curved surface guide member 23 Guide roller member

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takayuki Koike 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. In-company (56) References JP-A-63-135270 (JP, A) JP-A-6-47970 (JP, A) JP-A-5-286187 (JP, A) (58) Fields investigated (Int. . ^7, DB name) B41J 13/00 - 13/32

Claims (1)

(57) [Claims] A sheet feeding means for feeding sheet-shaped recording paper;
Paper transport means comprising a capstan roller and a pinch roller for transporting the recording paper after feeding, recording means comprising a thermal head for performing thermal transfer recording on the recording paper, an ink sheet, and a platen; and recording paper transport of the recording means on the downstream side
A curved paper guide means for changing the conveying direction of the recording paper in the vicinity of the apparatus wall, and the recording paper wound around the opposing surface of the paper guide means at a winding angle of an angle θ and a sliding load for conveying the recording paper. small and in possible rotated together with the recording paper
At least have a gap of several sheets of paper thickness and support it on a fixed shaft.
And a pair of guide roller means.