JPH0351230A - Paper feeding device and paper feeding cassette for printer - Google Patents

Abstract

PURPOSE:To securely prevent erroneous feeding by applying force to one of recording papers in a direction reverse to the direction of carrying the paper to a fitting device of a printer to provide a separation means for providing a gap at a boundary between the paper and the other recording papers before the paper to be fitted to a printer fitting device is carried to the fitting device. CONSTITUTION:A separation roller 1 is reversed in the direction of an arrow Tb for a predetermined time prior to paper feeding motion by a paper feeding command from a printer to convexly bend one of recording papers in contact with the separation roller 1 between the separation roller 1 and a part of the inner wall of a cassette 8 to separate the one from the other recording papers 10. Next, the separation roller 1 reversed for the predetermined time is rotated regularly to carry the separated recording paper 11 to the platen drum 2 side of the printer for printing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a paper feeding mechanism of a printer and a structure of a cassette.

[Prior art 3] It has been conventional to use cut sheets as recording sheets for printers, and the cut sheets are stacked and stored in a cassette. The general structure is as described in Japanese Patent Laid-Open No. 58-171979, in which a separation roller is provided above a cassette containing recording paper, and the stacked recording paper is separated one by one by rotation of the separation roller. It has become. The separated recording paper is mounted on a platen drum via a conveyance roller,
The image is printed using a thermal transfer sheet and a thermal head. The structure shown in the above conventional example differs from the printer structure of the present invention in the following points. In the conventional example, since cut sheets of plain paper are used as recording paper, printer troubles due to static electricity are rare, and the case of cut sheets of special paper such as synthetic paper is not mentioned at all.

This type of device is also described in Japanese Patent Laid-Open No. 59-55767 and Utility Model No. 58-20602.

[Problem to be solved by the invention]

The above prior art is written on paper B)? ! No consideration has been given to synthetic paper, which generates a large amount of static electricity due to friction, etc., and if synthetic paper is used as recording paper, it will not separate each sheet completely, leading to problems with printers (such as transporting multiple sheets of recording paper into the printer) There was a problem that caused so-called double feet.

An object of the present invention is to ensure the separation of stacked cut sheets and to prevent double feeding during printing.

[Means to solve the problem]

In order to achieve the above object, one sheet of the stacked recording sheets is first separated from the other recording sheets and then subjected to the conventional conveyance process.

Furthermore, a claw is provided on the inner wall of the recording paper storage cassette/box to ensure separation.

[Effect]

Before starting the paper feeding operation in response to a paper feeding command from the printer, the transport roller is reversed for a predetermined period of time, and the sheet of recording paper that is in contact with the transport roller is placed in a convex shape between the transport roller and a part of the inner wall of the cassette. After bending the recording paper and separating it from other recording paper, the conveyance roller, which rotated in reverse for a certain period of time, now rotated in the normal direction to convey the recording paper in the direction of the printer's platen drum for printing.

〔Example〕

A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 shows a schematic cross section of the inside of a thermal transfer printer.

A separation roller 1 is fixedly or movably provided above the cassette 8 in which the recording paper 10 is stored so as to be in contact with the recording paper 10. The support 9 is a jig for supporting the weight of the recording paper 10 and pressing it toward the separation roller 1, 61.62
is a recording paper transport roller that transports the separated sheet of recording paper 11 in the direction of the platen drum 2. 12 is recording paper 11
7 is an auxiliary roller for pressing the recording paper 11 onto the platen roller 2; 31, 32 is a paper roller that winds up or unwinds the ink paper 4; 5 is a recording paper sensor; A thermal head is shown that applies thermal energy to the ink paper 4 based on a signal.

FIG. 2 shows the relationship among the print start signal S1, the rotation directions Ta and Tb of the separation roller 1, and the output signal S12 of the recording paper sensor 12.

When a print start command S1 is input to the printer, the support 9 pushes up the stacked recording paper 10 and brings it into contact with the separation roller 1. The separation roller 1 rotates in the direction Tb to move the recording paper 10 away from the platen tram 2 for the duration of the first hole, and pushes the one recording paper 11 that has come into contact with the separation roller 1 out of the stacked recording papers 10 into a convex shape. Form a curved part. At this time, a gap is created between one curved sheet of recording paper 11 and the other recording paper 10, so that the edges pressed together when cutting the recording paper may easily separate, or the electrostatic attraction force of the contact surface may be reduced. This will lower the temperature and make it easier to transport. In this way, after the recording paper 11 is separated in a curved manner, the rotation of the separation roller 1 is reversed and the recording paper 11 is separated.
When the recording paper 11 is rotated in the direction Ta for conveying it to the platen drum 2 side, the recording paper 11 is conveyed toward the conveyance rollers 61 and 62 as shown by the broken line while trying to return to its original state (flat). Further, when the leading edge of the recording paper 11 is detected by the paper sensor 12, a detection signal S1
2 is output and the rotation of the 1 separation roller 1 is stopped to prepare for conveyance of the next recording paper. Alternatively, the support 9 may be lowered to eliminate contact between the separation roller 1 and the recording paper 10. In any case, the recording paper 11 is placed between the auxiliary roller 7 and the platen drum 2, and is attached to the platen drum 2 along a paper guide (not shown).6 The attached recording paper 11 is heat-sensitive. The ink paper 4 is pressed against the platen drum 2 at the position of the head 5, and ink having a density proportional to the thermal energy applied to the thermal head 5 is transferred onto the recording paper 11 to obtain a printed image.

There was no problem if the recording paper 10 was plain paper as in the past, but in thermal printers, such as sublimation dye printers, the recording paper 10 is made of synthetic paper or a dye layer is coated on the surface of the plain paper. Since special paper is used, static electricity of several thousand volts is generated due to frictional charging between two adjacent sheets of recording paper 10, and separation of recording paper 11 is extremely difficult due to the accompanying electrostatic force.

Particularly in the stacked state immediately after purchase from a recording paper manufacturer or recording paper retailer, most of the surface area of the recording paper is in contact, so the electrostatic force proportional to the contact area is large, making it difficult to separate the sheets. Yes, a double feed was definitely occurring. However, once separated and an air layer is created, static electricity is discharged into the atmosphere during separation, and ions are neutralized on the front and back sides through the surface of the paper, reducing static electricity.The air layer also reduces the contact area with the paper surface. It has been discovered that the electrostatic force decreases extremely, resulting in a dotted contact state, which reduces the electrostatic force and facilitates separation.

Furthermore, as mentioned above, the recording paper 10 used in image printers is often made of synthetic paper or special paper and has strong paper stiffness (elastic force due to flexibility), so it becomes curved as shown in Figure 1. There will be no creases and the finish of the print will not be affected. Further, the recording paper 1o is in contact with the separation roller 1.

If the surface 11 is the opposite side to the surface to be printed, that is, the back side of the recording surface, the separation roller 1 will not cause scratches, so the printed image will not be damaged.

A second embodiment of the present invention will be explained with reference to FIG.

FIG. 3 shows the cassette 8 and conveyance roller 61 in FIG.
This is an enlarged view of part 62.

Another separation roller 15 is provided in pressure contact with the conveyance roller 62. Since the separation roller 15 rotates in the opposite direction to the conveyance roller 62, even if a double feed occurs, the separation roller 15 can remove and separate the double-feeted unnecessary recording paper 16.

Therefore, reliability of paper feeding can be improved. The material of the separation roller 15 should not be made of a slippery material such as a fully bent one.
Materials with a large friction coefficient, such as rubber, make paper more likely to get caught, further improving the reliability of paper feeding.

A third embodiment of the present invention will be described with reference to FIG.

In FIG. 4, the recording paper 10 in the cassette 8 is deformed into a convex shape toward the separation roller 1 by setting the positional relationship between the support 9 and the separation roller 1. The distance Ql between the inner wall of the cassette 8 and the separation roller 1 is made smaller than the distance Q2 between the inner wall and the tip of the support 9. That is, Qs<fi
When set to z, the recording paper 1o is deformed into a convex shape at the same time as the support 9 is pushed up. If the operation shown in FIG. 1 is performed after this state is established, separation of the recording paper 10 will be more reliable.

FIG. 5 shows a fourth embodiment of the present invention. A separating claw 13 is provided at the upper part of the wall of the cassette 8 on the side of the transport rollers 61 and 62. The upper side of the separating claw 13 has an angle θ with the inner wall, making a 90° relationship.0 When the leading edge of the recording paper 11 separated by the separating roller 1 comes off the separating claw 13, the recording paper 11 and other recording papers are separated. 1o has the effect of ensuring reliable separation by the separation claw 13.

Furthermore, if the tip of the separation claw 13 that contacts the recording paper 1o is made into a pointed shape, the separation function can be further improved. Furthermore, if the upper side of the separating claw 13 is made streamlined or otherwise rounded, when the recording paper 10 is conveyed, the recording paper 10
It also has the effect of not damaging the surface.

Furthermore, if the tip of the separation claw 13 that contacts the recording paper 1o is made into a pointed shape, the separation function can be further improved.

FIG. 6 shows a fifth embodiment of the invention. In FIG. 6, a convex separating claw 14 is provided on a part of the inner wall of the cassette 8. As shown in FIG. According to this embodiment, when the support 9 pushes up the recording paper 10, the leading edge of the recording paper 10 comes into contact with the separating claw 13, and the stacked recording papers 10 are turned over one by one, and the separating roller 10
This has the effect of making separation easier. Furthermore, since the recording paper 10 is separated by 10a and 10b each time it is recorded, it is possible to reduce the accumulation of static electricity.

FIG. 7 shows a sixth embodiment of the present invention. In FIG. 7, the recording paper 11 is separated into convex shapes without using the separating roller 1, but by a separating means 15 such as a suction machine, and after separation, the recording paper 11 is conveyed by the separating roller 1. 1
The movement can be made in one direction, which has the effect of reducing the range of motion.

Although the separation roller 1 of the present invention has been described in a two-dimensional representation, the length in the depth direction should be appropriately selected depending on the width of the recording paper 10, and the material should preferably be one with a large coefficient of friction (for example, rubber). There is.

In the first to sixth embodiments described above, the command to feed the recording paper, the command to separate the recording paper, and further the command to control these mechanisms may be given from a control unit inside the printer. However, it may be given from a control unit external to the printer.

Furthermore, the external control unit of the above printer is the CPU (Ce) of a personal computer or workstation.
It may be a central processing unit (processing unit) or a CPU of a large computer. In other words, it is sufficient to have a mechanism that can generate a print command regardless of the speed of arithmetic processing or the size of information processing. Of course, a word processor, a notebook type computer, a word processor, etc. may also be used.

Note that the printer control described above is issued based on the result of judgment, so it does not need to be the result of computer calculations.
Pressing a button and issuing control commands to feed paper based on human judgment,
Needless to say, you can also start printing.

〔Effect of the invention〕

According to the present invention, by changing the conventionally used separation roller 1 to the structure according to the present invention, it is possible to reliably prevent misfeeds, especially budal feeds, that occur when a plurality of recording sheets 10 are conveyed.

Furthermore, the paper feeding function can be significantly and reliably improved without increasing the price of the device. In addition, since misfeeds can be prevented, it is possible to prevent the increase in expenses due to collecting and inspecting the printer, and it has the mental effect of not only reducing the reliability of the printer's operation but also not damaging the customer's trust6.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of one embodiment of the present invention, FIG. 2 is a signal timing chart for explaining FIG. 1, and FIGS. 3 to 7 are side views showing other embodiments of the present invention. It is. ■, 15...Separation roller, 8...Cassette, 9...
・Support, 10.11...Recording paper, 13.14...
Separation claw, 1 Fig. 1 Fig. Fig. Fig. Fig. Fig. U

Claims (1)

[Scope of Claims] 1. A printer that has a cassette containing recording paper, stacks cut recording paper on the cassette, and loads the paper sheets one by one into a device during printing to print on the recording paper with a thermal head, Separating means for applying force in a direction opposite to the direction in which one sheet of recording paper to be loaded into the printer loading device is conveyed to the loading device to create a gap between the recording sheets and other recording sheets; A paper feeding device for a printer, comprising a conveyance means for conveying the recording paper to the mounting device after passing through the separation means. 2. The paper feeding device for a printer according to claim 1, wherein the separating means also serves as the conveying means. 3. A separating roller is provided between the cassette and the loading device, and a recording paper conveyance roller and a separation roller that contacts one of the conveyance rollers and reverses the recording paper to the side opposite to the loading device side. A paper feeding device for a printer according to claim 1. 4. A paper feeding cassette for a printer, characterized in that the cut recording paper stored in the cassette is deformed into a convex shape toward the separating means at least only when the recording paper is loaded. 5. A paper feeding device according to claim 1, characterized in that the paper feeding cassette according to claim 4 is used. 6. A paper feed cassette for a printer, characterized in that a protruding separating claw is provided on a part of the inner wall of the paper feed cassette. 7. A paper feeding device according to claim 1, characterized in that the paper feeding cassette according to claim 6 is used. 8. A plate-shaped or protruding separating claw is provided on the inner wall of the cassette at or near the upper end of the cassette, and the angle θ between the inner wall of the cassette and the upper side of the separating claw is less than 90 degrees. Printer paper cassette. 9. A paper feeding device according to claim 1, characterized in that the paper feeding cassette according to claim 8 is used. 10. A printer comprising the paper feeding device according to claim 1, and the paper feeding cassette according to claim 4, the paper feeding cassette according to claim 6, or the paper feeding cassette according to claim 8. 11. An information processing apparatus characterized in that the printer according to claim 10 is used as a printer that prints a result of processing information.