JP2692997B2 - Image printer - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording device having an automatic paper feeding mechanism, and more particularly to an image printer.

2. Description of the Related Art In recent years, some image printers have an automatic paper feed mechanism for continuously and automatically supplying a special recording paper such as a PET base to a recording unit in the apparatus.

Hereinafter, an example of a conventional image printer will be described with reference to the drawings. FIG. 3 shows a sectional view of a conventional image printer. In FIG. 3, a recording unit including a thermal head 1, a platen 2 and an ink sheet 3 is provided in a main body 14 of an apparatus, and a capstan 4 for driving a recording paper 15 after being fed is provided on the upstream side in the paper feeding direction. A pinch roller 5 is provided, a switching guide 6 for switching between sheet feeding and sheet discharging is provided upstream of the pinch roller 5, and a separate roller 7 is provided further upstream thereof.
A pickup roller 8 is rotatably provided, and a conveyor belt 9 is stretched between the pickup roller 8 and the separate roller 7. Further, a reverse roller 10 is provided at a position corresponding to the separate roller 7, and the reverse roller 10 has a torque limiter coaxially and can rotate, and a reverse roller holding unit rotatably attached to the apparatus body 14. It is held by the angle 11 so that it can come into contact with the conveyor belt 9 on the side of the separate roller 7. Also, the guide plate 12 is a separate roller 7.
To the platen 2 of the recording unit and guides the recording paper 15 after being fed. A recording paper cassette 16 accommodating a sheet-shaped recording paper 15 is detachably attached to the guide portion 13 of the apparatus main body 14. The paper pressing plate 17 is provided so as to be rotatable around one end, and the recording paper 15 stored in the recording paper cassette 16 is stacked on the paper pressing plate 17, and the lifting lever 18 holds the paper pressing plate 17 at one end. The recording paper 15 is pressed against the conveyor belt 9 when the recording paper 15 is pivoted up and pushed up.

For the conventional image printer configured as described above,
The operation will be described below. First, a recording paper cassette 16 containing a plurality of recording papers 15 is inserted and held at a predetermined position along a guide portion 13 of the apparatus main body 14. At the time of paper feeding, the push-up lever 18 is rotated upward, the paper pressing plate 17 is rotated with one end as a fulcrum and the other end is pushed up, and the recording paper 15 stacked on the paper pressing plate 17 is conveyed by the conveyor belt. Press 9 Next, as the pickup roller 8 or the separate roller 7 rotates, the transport belt 9 is driven in the paper feeding direction, and one or several recording papers 15 are transported.

On the other hand, at the time of paper feeding, the reverse roller 10 which is separated from the separate roller 7 is rotated in the direction in which the reverse roller holding angle 11 presses the recording paper 15, and the separate roller 9 is conveyed via the conveyor belt 9. Press. Here, the reverse roller 10 is provided with a torque limiter on the same axis, and has the role of allowing the recording paper 15 to be conveyed as it is if it is one sheet of recording paper, and separating the second or more sheets if it is two or more sheets. There is. The conveyed one recording paper 15 is guided by the guide plate 12 and the switching guide 6, passes between the capstan 4 and the pinch roller 5, is detected by the sensor, and the conveyance is completed.

When the transportation is completed and the recording paper 15 is sandwiched between the capstan 4 and the pinch roller 5 and sent to the recording unit, the push-up lever 18 is lowered, and at the same time, the reverse roller 10 is also lowered by the reverse roller holding angle 11. Return to the initial position. At this time, the reverse belt is carried by the carrying belt 9.
As shown in FIG. 4, the recording paper 15 separated by the paper 10 is placed on the upper end surface of the recording paper cassette 16 and the reverse roller 10
May be left on the top surface of. In this state, the recording paper 15a conveyed to the first sheet, the recording paper cassette 16 and the recording paper 15b mounted on the reverse roller 10
Contact with each other and adhesion due to static electricity occurs
I will take it inside 14. For this reason, some conventional image printers have a recording paper scraping mechanism as shown in FIG.

In FIG. 5, reference numeral 19 denotes a scraping lever rotatably supported on the shaft of the pickup roller 8, and the tip end of the scraping lever 19 is biased downward by a biasing spring 20. When feeding the paper, the pick-up lever 19 is lifted to convey the recording paper 15a, and when the conveyance is completed, the reverse roller 1
The reverse roller 1 that rotates the second and subsequent recording papers 15b in the reverse transport direction by lowering the scraping lever 19 with the decrease of 0
The recording paper 15b is returned by urging the recording paper 15b so that the recording paper 15b is brought into contact with the recording paper 15b.

SUMMARY OF THE INVENTION However, in the above-described configuration, when the scraping mechanism is not provided, the recording paper 15b remains on the upper surface of the reverse roller 10 and remains, and the first conveyed recording paper 15a. The second and subsequent sheets of recording paper 15b mounted as described above on
However, there is a problem in that when they contact each other, they are brought into close contact with each other due to static electricity, and are repeatedly fed into the inside of the apparatus main body 14, resulting in a paper feed error.

Further, in the image printer having the paper scraping mechanism as shown in FIG. 4, the lever portion of the scraping bar 19 is set to the upstream side of the reverse roller 10 in the paper feeding direction, and the biasing spring 20 always moves downward. The first recording paper 15
When a is conveyed, the end face of the recording paper 15a is scraped off and pushes up the lever part of the reper 19 to advance, which is a load of conveyance, and the lever part is not directly in contact with the reverse roller. If the spring pressure of the urging spring 20 is set to a strong spring pressure effective to prevent double feeding, there are problems such as occurrence of paper feeding slip and delay of paper feeding time.

The present invention solves the above problem by providing a reverse roller having a width wider than that of a conveyor belt or a roller, and by bringing a scraping lever into contact with the reverse roller, it is possible to prevent double feeding with a weak load, and to prevent slipping or feeding of paper. An object of the present invention is to provide a highly reliable image printer that does not delay the paper feeding time.

Means for Solving the Problems To solve the above problems, the image printer of the present invention is
A recording paper cassette for storing sheet-shaped recording paper, a conveyor belt or roller which is provided above the recording paper cassette and conveys the recording paper when the stored recording paper comes into contact with the recording paper cassette. A paper pressing plate that presses the recording paper against the conveyor belt or the roller from below, and is provided on the downstream side of the conveyor belt or the roller in the sheet feeding direction so as to be able to press the conveyor belt or the roller. A reverse roller configured to separate the first and subsequent sheets and wider than a conveyor belt or a roller, and a lever member that is rotatable so that its leading end contacts both ends of the reverse roller from above. And a biasing means for biasing the tip of the lever member so as to contact the reverse roller.

Action With the above-described configuration, the scraping lever is in contact with the reverse roller, which causes the scraping lever to be lifted to the same height as the conveyor belt or the roller at the time of feeding, and the scraping lever is the first sheet. The load of lifting the recording paper can be reduced, and when the paper feed is completed, the drop-off lever follows the lowering of the reverse roller and moves down while holding the recording paper. Although conveyed by the pressing rotation of the stun and pinch rollers, the second and subsequent recording sheets are directly pressed by the reverse rotating reverse roller, and a strong reverse returning force is generated, and the recording sheets are returned to the recording sheet cassette.

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

FIG. 1 is a cross-sectional view showing the configuration of an image printer according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a main part of the image printer. In FIGS. 1 and 2, those having the same numbers as those of the conventional example indicate the same parts, and the detailed description thereof will be omitted. A reverse roller 30 is configured to have a width wider than that of the conveyor belt 9, and the tip end of the scraping lever 19 can contact the upper surface of the reverse roller 30.

Regarding the image printer thus configured,
The operation will be described. First, a recording paper cassette 16 accommodating a plurality of recording papers 15 is inserted and held at a predetermined position along the guide portion 13 of the apparatus body 14. When feeding, push up lever 18
Rotates upward, the paper pressing plate 17 is rotated with one end as a fulcrum and the other end is pushed up, and the recording paper 15 stacked on the paper pressing plate 17 is pressed against the transport belt 9. Next, the pickup roller 9
Alternatively, when the separate roller 7 rotates, the conveyor belt 9 is driven in the paper feeding direction, and one or several recording sheets 15 are conveyed. On the other hand, at the time of feeding, the reverse roller 30 which is separated from the separate roller 7 is rotated in the direction in which the reverse roller holding angle 11 presses the recording paper 15, and the separation roller 7 is inserted through the recording paper 15. Press. Here, the reverse roller 30 is provided with a torque limiter on the same axis, and operates so as to separate the second and subsequent recording sheets 15. The scraping lever 20 is a biasing spring 20.
Although it is in contact with the upper surfaces of both sides of the wide reverse roller 30 by the above, it does not become a large carrying load because it is lifted to the same height as the carrying belt 9.

One sheet of recording paper 15 that has been conveyed is guided by the guide plate 12 and the switching guide 6, passes between the capstan 4 and the pinch roller 5, and is conveyed when it is detected by the sensor.

When the conveyance is completed and the recording paper 15 is sandwiched between the capstan 4 and the pinch roller 5 and sent to the recording paper, at the same time, the reverse roller 30 is also rotated by the reverse roller holding angle 11 in the direction of separation to move to the initial position. Return to position. At this time, since the scraping lever 19 is urged so as to contact both ends of the reverse roller 30, it moves following the reverse roller 30 and clamps the recording paper 15. The recording paper 15a is conveyed to the recording unit by the pressing rotation of the capstan 4 and the pinch roller 5, but the second and subsequent recording papers 15b are directly pressed by the reverse rotating reverse roller 30 and a reverse return force is generated. By recording paper cassette 16
Will be returned to.

As described above, according to the present embodiment, the recording paper cassette that stores the recording paper, the conveyor belt that is provided above the recording paper cassette, the paper pressing plate that presses the recording paper against the conveyor belt, and the conveyor belt. Is provided on the downstream side of the
It can be pressed against the conveyor belt, operates so as to separate the second and subsequent sheets of recording paper when pressed, and the reverse roller, which is wider than the conveyor belt, and its tip end contacts both ends of the reverse roller from above. Thus, by providing a rotatable lever member and a biasing means for biasing the tip of the lever member so as to contact the reverse roller, double feeding of recording paper and paper feeding slip caused by adhesion force due to static electricity ,
It is possible to prevent a delay in paper feeding time.

Although the conveyor belt is stretched between the two shafts in this embodiment, two conveyor rollers may be used as the conveying means.

As described above, according to the present invention, the reverse roller for separating the recording paper is configured to be wider than the conveyor belt,
Since lever members for scraping off the second and subsequent recording sheets are brought into contact with both ends of this reverse roller from above,
With a weak biasing force, it is possible to effectively prevent double feed caused by static electricity sticking to each other on recording papers, and also to prevent paper feed slips and delays in paper feed time, dramatically improving reliability. The effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of an image printer according to an embodiment of the present invention, FIG. 2 is a perspective view of a main portion of the image printer, FIG. 3 is a sectional view of a conventional image printer, and FIG. FIG. 5 is a sectional view of the main part of the printer, and FIG. 5 is a perspective view of the main part of another embodiment of the conventional image printer. 2 ... Platen, 4 ... Capstan, 5 ... Pinch roller, 7 ... Separate roller, 8 ... Pickup roller, 9 ... Conveyor belt, 11 ... Reverse roller holding angle, 15 ... Recording paper, 16 …… Recording paper cassette, 17 ……
Paper pressing plate, 19 …… Keeping lever, 30 …… Reverse roller.

Claims (1)

(57) [Claims] 1. A recording paper cassette for accommodating a sheet of recording paper, and a conveyor belt which is provided above the recording paper cassette and conveys the recording paper when the accommodated recording paper comes into contact with each other. A roller, a paper pressing plate that presses the recording paper from the lower part of the recording paper cassette to the conveyor belt or roller, and a paper pressing plate that is provided on the downstream side of the conveyor belt or roller in the sheet feeding direction and presses the conveyor belt or roller. A reverse roller which is configured to separate the second and subsequent sheets of the recording paper when pressed and has a width wider than that of the conveyor belt or the roller; Image provided with a lever member rotatable so as to come into contact with the reverse direction, and a biasing means for biasing the tip end portion of the lever member so as to come into contact with the reverse roller Printer.