JPH0445031A - Image printer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image printer with an automatic paper feed mechanism.

BACKGROUND OF THE INVENTION In recent years, some image printers are equipped with an automatic paper feeding mechanism to continuously and automatically feed special recording paper such as PET-based paper to the recording section within the device. Ta.

An example of the above-mentioned conventional double-image printer will be described below with reference to the drawings.

FIG. 3 shows a cross-sectional view of a conventional image printer. In FIG. 3, 14 indicates a thermal head 1, a platen 2. The main body of the apparatus has a recording section consisting of an ink sheet 3; 8 is a pickup roller rotatably provided on the main body 14 of the apparatus; 7 is a separate roller rotatably provided on the main body of the apparatus similar to the pick-up roller 8; 16 is a separate row 777 [ 17 is a reverse roller 16 that can be pressed and has a sittle limiter on the same axis and can rotate.
12 is a sheet of recording paper; 11 is a recording paper that stores the recording paper 12 and is detachable from the guide portion 18 of the apparatus main body 14; a cassette; 13 is a pressing means for pressing the recording paper 12 against the pickup roller 8; 1o is a paper pushing plate that presses the recording paper 12 while stacking it by the pressing means;
6 is a switching guide for switching between paper feeding and paper ejection; 1
6 is a guide member that guides the recording paper 12, and 4.5 is a pinch roller and a capstan roller that transport and drive the recording paper 12 after being fed.

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

First, a recording paper cassette 11 containing a plurality of recording papers 12
is inserted and held in a predetermined position along the guide portion 18 of the device main body 14. When feeding paper, the pressing means 13 rises, and the paper pushing plate 1o is rotatable about one end on the upstream side in the paper feeding direction as a fulcrum.
is pushed up to press the recording paper 12 on the paper pusher plate 10 against the pickup roller 8. At the same time, the pickup roller 8 and the separate roller 7 rotate in the paper feeding direction to convey a plurality of sheets of recording paper 12. On the other hand, when feeding paper, separate roller 7
The reverse roller 16, which was separated from the recording paper, presses the separate roller 7 by rotating the reverse roller holding angle 17 about the fulcrum in the direction of suppressing the recording paper. Here, the reverse roller 16 is equipped with a torque limiter and rotates in the opposite direction with respect to the paper feeding direction, so that if it is one sheet of recording paper 12, it is conveyed as it is, and if it is two or more sheets, it is handled after the second sheet. It forms a means of judgment.

The conveyed sheet of recording paper 12 is guided by the guide member 15 and the switching guide 6 and passes between the capstan roller 4 and the pinch roller 6 to complete the paper feeding operation. The pressing means 13 and the tribune roller 16 descend.

At this time, the recording paper 12 separated by the reverse roller 16
may climb onto the upper surface of the reverse roller 16, as shown in FIG. In this state, when the first recording paper 12& and the recording paper 12b riding on the upper surface of the lino roller 16 come into contact with each other, an adhesion force is generated due to static electricity, causing double feeding to be carried into the main body 14 of the apparatus. It had occurred.

In order to prevent this, some conventional printers are equipped with a recording paper ejecting mechanism as shown in FIG.

In FIG. 5, a brush drop lever 20 is rotated around the axis of the pickup roller 8, and is biased by a biasing means 21 so as to clamp the vicinity of both ends of the reverse roller 16 from above. .

When feeding paper, the edge drop lever 2o is lifted by the recording paper 12a conveyed by the pick-up roller 8, but when paper feeding is completed, the edge drop lever 20 also moves toward the recording paper as the reverse roller 16 descends. It descends while energizing 12a. Here, the second and subsequent sheets of recording paper 12b are likely to be fed double due to close contact due to static electricity, but it is possible that the river 70-16 is rotating in the opposite direction.
A reverse conveying force is generated, and the second and subsequent sheets of recording paper 12b are returned in the direction of the recording paper force center.

Problem to be Solved by the Invention However, in the above configuration, if there is no drop-off mechanism, the recording paper 12b will remain on the upper surface of the reverse roller 16, and the one recording paper that has been conveyed will be When the second or subsequent recording paper 12b comes into contact with the recording paper 12a, static electricity causes close contact with the recording paper 12b, causing double feeding into the apparatus main body 14, resulting in a paper feeding error. Further, as shown in FIG. 6, in the image printer 7 equipped with a kick-off mechanism, the lever portion of the kick-off lever 20 is always urged downward by the biasing means 21, so that double feeding can be prevented. If the spring pressure is set to a strong spring pressure that is effective for
There was a problem in that the recording paper being conveyed for the first sheet slipped.

In view of the above-mentioned problems, the present invention includes a rotatable lever member that pinches both ends of a reverse roller and the upstream side of the reverse roller in the paper feeding direction from above and abuts at an acute angle with respect to the paper feeding direction of recording paper. By providing a biasing means for biasing a lever member, it is possible to prevent double feeding and paper feeding slip with a small load, and to provide a high quality and highly reliable image printer that does not damage recording paper.

Means for Solving the Problems In order to solve the above problems, the image printer of the present invention has a recording paper cassette 7) for storing sheets of recording paper, and a first cassette for transporting the recording paper above the recording paper cassette. a conveyance roller, a paper push-up plate that presses the recording paper against the first conveyance roller from below the recording paper cassette, and a second conveyance roller provided substantially parallel to the first conveyance roller downstream in the paper feeding direction; A reverse roller that presses and separates the second conveyance roller from below and handles the second and subsequent sheets of recording paper, and a reverse roller that presses and separates the second conveyance roller from below and handles the second and subsequent sheets of recording paper. The structure includes a lever member that abuts at an acute angle and is rotatable, and a biasing means for biasing the lever member.

Function The present invention has the above-described configuration, and the kick-off lever generates a force that winds the second and subsequent sheets of recording paper downward around the reverse roller, generating a strong reverse conveying force, so the biasing force is set weakly. This can prevent double feeding. Further, by setting the biasing force weakly, the load on conveying the first recording paper is reduced, and paper feeding slip can be prevented. Furthermore, since the contact area between the scraping lever and the recording paper is increased, the pressure per unit area is reduced and scratches are less likely to occur.

Embodiment Hereinafter, an image printer according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing the configuration of an image printer in an embodiment of the present invention, and FIG. 2 is a perspective view thereof. In Figures 1 and 2, 1
4 is a thermal head 1° platen 2. The main body of the apparatus has a recording section consisting of an ink sheet 3; 8 is a pickup roller rotatably provided on the main body 14 of the apparatus; 8 is a separate roller rotatably provided on the main body of the apparatus similar to the pick-up roller 8; 1θ is a separate roller 7; p) A reverse roller that can be pressed and that can be rotated by holding a torque limiter on the same axis;
17 is a reverse roller holding angle which holds the reverse roller 16 and is rotatably attached to the main body 14 of the apparatus; 12 is a sheet of recording paper; 11 is a guide for storing the recording paper 12 and for the main body 14 of the apparatus; Removable recording paper cassette, 13
1 is a pressing means for pressing the recording paper against the pink up roller 8; 1o is a paper pushing plate that presses the recording paper 12 while stacking it; 6 is a switching guide for switching between paper feeding and paper ejection; 15 is a guide member that guides the recording paper 12; 4.6 is a pinch roller and a capstan roller that drive the recording paper after it has been fed; 22 is a kick-off lever, which uses the axis of the pickup roller 8 as its pivot axis; The biasing means 21 biases both ends of the reverse roller 16 and the upstream side in the paper feeding direction from above.

The operation of the image printer according to an embodiment of the present invention configured as described above will be described below.

First, a recording paper cassette 11 containing a plurality of recording papers 12
is inserted and held in a predetermined position along the guide portion 18 of the device main body 14. When feeding paper, the pressing means 13 rises, and the paper pushing plate 1o is rotatable about one end on the upstream side in the paper feeding direction as a fulcrum.
is pushed up to press the recording paper 12 on the paper pusher plate 1o against the pickup roller 8. At the same time, the pickup roller 8 and the separate roller 7 rotate in the paper feeding direction to convey a plurality of sheets of recording paper 12. Here, the recording paper 12 comes into contact with the kick-off lever 2, which comes into contact with the recording paper 12 from above at an acute angle with respect to the paper feeding direction.
2 is flipped up and conveyed to the separate roller 7. On the other hand, during paper feeding, the reverse roller 16, which was separated from the separate roller 7, moves to the reverse roller holding angle 1.
The separation roller 7 is pressed by rotation about the fulcrum in the direction of pressing the recording paper. Here, the reverse roller 16 is equipped with a torque limiter and rotates in the opposite direction with respect to the paper feeding direction, so that if it is one sheet of recording paper 12, it will convey the recording paper 12 as it is, and if it is two or more sheets, it will not move the second and subsequent sheets. It forms a means of judgment that results in

The transported sheet of recording paper 12a is guided by the guide member 16 and the switching guide 6, passes between the capstan roller 4 and the pinch roller 6, and the paper feeding operation is completed. It is conveyed by the pressure and rotation of the roller 5, and the pressing means 13 and reverse roller 16 descend. Further, the kick-off lever 22 also descends while urging the recording paper 12&, and the recording paper 12a is sandwiched between the reverse rows 916. At this time, the recording paper 12b is conveyed by the pickup roller 8 and separated by the reverse roller 16. When the recording paper 12 comes in contact with the recording paper 12 and causes static electricity, it tries to double feed, but the kicking lever 22 comes into contact with both ends of the reverse roller 16 and the upstream side in the paper feeding direction from above at an acute angle. Then, the second and subsequent sheets of recording paper 12b receive a downward winding force around the reverse roller 16, generate a strong reverse conveying force, and return to the recording paper cassette 11. Therefore, double feeding can be prevented by setting the biasing force weaker than in the past. Further, by setting the biasing force weakly, the transport load of the first recording paper 12& can be reduced and paper feeding slip can be prevented. Furthermore, since the contact area between the edge removal lever 22 and the recording paper 12 is increased, the pressure per unit area is reduced and scratches are less likely to occur.

Effects of the Invention As described above, the image printer of the present invention includes a recording paper cassette that stores sheets of recording paper, a first conveyance roller that conveys the recording paper above the recording paper cassette, and a lower part of the recording paper cassette. a paper push-up plate that presses the recording paper against the first conveyance roller; a second conveyance roller installed approximately parallel to the downstream side of the first conveyance roller in the paper feeding direction; A reverse roller that presses and separates the second conveyance roller and handles the second and subsequent sheets of recording paper, and a reverse roller that pinches both ends of the reverse roller and the vicinity of the upstream side in the paper feeding direction from above, forming an acute angle with respect to the paper feeding direction of the recording paper. By providing a lever member that can be rotated in contact with each other and a biasing means that biases the lever member, double feeding, paper feed slips, and damage to recording paper are prevented with a small load, and quality and reliability are greatly improved. It is possible to obtain the excellent effect of increasing the

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of an image printer according to an embodiment of the present invention, FIG. 2 is a perspective view of main parts in the same embodiment,
3 and 4 are cross-sectional views showing the configuration of a conventional image printer, and FIG. 6 is a perspective view of essential parts of the conventional image printer. End... Separate roller, 8... Pick up roller, 1o... Paper push-up plate, 12...
... Recording paper cassette, 16 ... Reverse roller, 21 ... Urging means, 22 ... 9 drop lever Name of agent Patent attorney Shige Takashi Awano 1 other person ^
1/ , , rash diagram θ

Claims (1)

[Claims] a recording paper cassette that stores sheets of recording paper; a first conveyance roller that conveys the recording paper above the recording paper cassette; and a first conveyance roller that conveys the recording paper from below the recording paper cassette. a paper push-up plate that presses the paper, a second conveyance roller provided substantially parallel to the paper feeding direction downstream of the first conveyance roller, and a paper push-up plate that presses the second conveyance roller from below the second conveyance roller. - A reverse roller that separates and handles the second and subsequent sheets of the recording paper, and a rotating roller that contacts both ends of the reverse roller and the vicinity of the upstream side in the paper feeding direction from above at an acute angle with respect to the paper feeding direction of the recording paper. An image printer comprising a movable lever member and a biasing means for biasing the lever member.