JP2002067420A - Thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of shift between sheets at the time of carrying a thermal multiple copy sheet. SOLUTION: A thermal printer 1 having a print section 10 comprising a platen 12 and a thermal head 13 abutting against the platen at a print position 15 through a sheet passage 11 in the vicinity of a sheet discharge port 6 in the sheet passage 11 extending from a sheet feed port 8 to the sheet discharge port 6 in a housing provided with the sheet feed port 8 and the sheet discharge port 6 is provided with a regulation member 16 having one end part secured to the housing and the other free end extending along the outer surface 2L of the housing from the thermal head 13 side to the platen 12 side while traversing the sheet discharge port 6. At the time of printing on a thermal multiple copy sheet 110, the thermal multiple copy sheet 110 carried in the sheet passage 11 and passed through the print position 15 is pressed against the outer surface 2L of the housing by the regulation member 16 immediately after passing through the print position 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer for printing on a recording material using a thermal head.

[0002]

2. Description of the Related Art Conventionally, a recording material having a thermosensitive coloring property inserted in a nip portion between a platen and a thermal head is used.
There is a thermal printer in which printing is performed on a recording material by heating with a heating element of a thermal head while being conveyed by a platen. The thermal printer is excellent in quietness in printing and suitability for miniaturization.

An outline of such a thermal printer will be described with reference to FIGS. FIG. 5 is a sectional view schematically showing a portable thermal printer.
The thermal printer 100 includes a paper path 102 in a housing 101 for guiding a recording material to a predetermined path. In the paper path 102, there is provided a printing unit 106 having a platen 103 driven to rotate by a motor (not shown) and a thermal head 104 abutting on the outer peripheral surface of the platen 103 via the paper path 102. The thermal head 104 includes a plurality of heating elements that generate heat based on print data transmitted to the thermal printer 100.
(Not shown) at the nip portion 106a.
It is arranged so as to abut.

In such a thermal printer 100,
As shown in FIG. 7, a plurality of recording materials (here, three
The thermal multiplex copying paper 110 in which the thermal papers 107, 108, and 109 are superposed on each other may be applied. In this thermal multiplex copying paper 110, all thermal papers 107, 1
Various studies have been made to maintain good print quality at 08,109. As one of them, the heat from the thermal head 104 is transferred to each of the thermal papers 107, 108,
In order to transmit the thermal paper to the thermal paper 107,
There is a thermosensitive multiplex copying paper 110 provided with a wax layer (not shown) having excellent thermal conductivity between 8,109. Thereby, the heat from the thermal head 104 is transferred to each of the thermal papers 107,
108, 109 and all thermal paper 10
Good print quality is maintained at 7, 108 and 109.

In general, thermal multiplex copying paper 110 used in the above-described thermal printer 100 is designed so that the thermal papers 107, 108, and 109 do not separate during printing, and can be easily printed after printing. Binding part 1 whose one side is stopped by glue or the like so that it can be separated into
It is assumed to be 11.

[0006]

Here, the nip 10
The behavior of the thermal multiplex copying paper 110 when passing through the sheet 6a will be considered with reference to FIGS. For convenience,
In the thermal multiplex copying paper 110, the thermal head 104
Assuming that the upper side is the upper side, in the thermal printer 100 described above, the transport force of the platen 103 is set to the lowest thermal paper
The heat-sensitive multiplex copy paper is conveyed by transmitting to the lowermost paper (109). On the other hand, the uppermost thermal paper (hereinafter referred to as the uppermost paper) 107 is in contact with the thermal head 104 whose position is fixed. For this reason, the nip portion 106
In a, between the top paper 107 directly printed by the thermal head 104 and the thermal head 104,
A frictional force μ is applied between each of the thermal papers 107, 108 and 109 and between the lowest paper 109 and the platen 103.
1, μ2 and μ3 act. Generally, friction force μ1, μ
2 and μ3, the state where the relationship of μ1 <μ2 <μ3 is established is an ideal relationship in which the thermosensitive multiplex copying paper 110 can be favorably conveyed.

By the way, as described above, the nip 10
6a, the conveying force of the platen 103 is the lowest paper 1
Since the uppermost sheet 107 is transmitted to only the thermal head 104 and is in contact with the fixed thermal head 104, the uppermost sheet 107 has a greater resistance in the advancing direction than the lowermost sheet 109.

Further, in the thermal multiplex copying paper 110, as described above, since a wax layer (not shown) is provided between the thermal papers 107, 108, 109, each thermal paper 10
The frictional force μ2 acting between the thermal papers 107, 108, and 109 tends to be low, and slippage tends to occur between the thermal papers 107, 108, and 109.

For this reason, as shown in FIG. 7, the lower thermal paper 108 or 109 is lower than the upper thermal paper 107 or 10.
8 is easier to advance than a single thermal multi-copy paper 1
In 10, the degree of progress is different between the upper order and the lower order. Hereinafter, a difference in the degree of progress between a higher order and a lower order in a single thermosensitive multiplex copy sheet 110 is referred to as a sheet shift.

Since the press contact force between the platen 103 and the thermal head 104 is acting on the nip 106a, the above-mentioned misalignment between the sheets is caused by the nip 106a.
It is thought that this occurs on the downstream side in the transport direction.

However, in practice, the sheet gap that occurs immediately after passing through the nip 106a
Therefore, the printing position is different for each thermal paper and the printing quality is degraded.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a thermal printer which can prevent the occurrence of a paper gap during conveyance of thermal multiplex copy paper.

[0013]

According to a first aspect of the present invention, there is provided a thermal printer comprising: a sheet path for guiding a recording material to a predetermined path; a platen provided in the sheet path and driven to rotate; A printing unit having a thermal head that abuts at a printing position via the paper path, and is provided downstream of the printing unit in the paper path in the transport direction of the recording material, and passes through the printing position. A pressing member that presses the recording material in the thickness direction so as not to hinder the conveyance of the recording material.

Therefore, when the thermal multiplex copying paper is transported, the thermal multiplex copying paper that has passed the printing position is pressed down in the thickness direction to such an extent that the transport is not hindered by the pressing member. This makes it possible to apply a pressing force in the thickness direction to the thermal multiplex copy paper after passing through the printing position.

According to a second aspect of the present invention, in the thermal printer according to the first aspect, the thermal printer further includes a housing-shaped housing in which a paper feed port and a paper discharge port are formed, and the printing unit is disposed in the housing. The paper path extends from the paper supply port to the outside of the housing from the paper discharge port via the inside of the housing, and the pressing member has one end fixed to the housing and the other end connected to the housing. A restricting member having a free end extending from the thermal head side to the platen side along the outer surface and extending across the sheet discharge port, and the outer surface of the housing with which the restricting member comes into contact.

Therefore, when the thermal multiplex copying paper is conveyed, the thermal multiplex copying paper that has passed the printing position is pressed from the thermal head side to the outer surface of the housing by the regulating member. This makes it possible to use the housing to apply a pressing force in the thickness direction to the thermal multiplex copying paper after passing through the printing position.

The third aspect of the present invention is the first or second aspect.
In the thermal printer described above, the paper path is bent along an outer peripheral surface of the platen.

Therefore, the thermal multiplex copying paper conveyed in the paper path is bent at the printing section with the thermal head side as the outer peripheral side. By this, for example, general slips,
When transporting the thermal multiplex copying papers that are bound together at least at the binding portion provided at at least one end, the paper path is merely bent along the outer peripheral surface of the platen, and the paper path becomes the outer peripheral side by bending. The force to pull the thermal paper on the thermal head side toward the platen side via the binding portion by the thermal paper on the inner peripheral side and the force by the regulating member to press the thermal multiplexed copy paper against the outer surface of the housing are substantially reduced. It is possible to operate in the same direction.

The invention according to claim 4 is the invention according to claim 2 or 3.
In the thermal printer described above, the one end of the regulating member is fixed inside the housing.

Therefore, it is possible to more effectively apply a force for pressing the thermal multiplex copying paper from the thermal head side in the thickness direction.

According to a fifth aspect of the present invention, in the thermal printer according to the second, third or fourth aspect, the regulating member is a sheet-like member having a width substantially equal to a width dimension of the paper discharge port.

Therefore, the operation according to the second, third, or fourth aspect can be realized with a practically simple configuration.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. This embodiment shows an example of application to a portable information terminal device having a built-in printing device for performing printing by a thermal method as a thermal printer.

FIG. 1 is a plan view showing an information terminal device according to an embodiment of the present invention, and FIG. 2 is a side view showing a part of the device in cross section. The information terminal device 1 includes a housing 2 having a flat housing shape. The housing 2 is formed by an upper housing 2a and a lower housing 2b integrally formed by a mold.

The upper housing 2a is provided with an input section 3 having various operation keys, an operation display section 4 having a touch panel laminated thereon, and the like. The input unit 3 has a power switch 3
a, a numeric keypad 3b, a function key 3c, and the like. Also, the upper surface rear of the upper housing 2a (FIG. 1)
In the middle (upper side), there is formed a paper discharge port 6 to which a printed slip is issued. A grip portion 7 to be gripped by an operator is formed on the upper side of the upper housing 2a.

On the front surface of the housing 2, a paper feed port 8 into which a heat-sensitive recording material is inserted is formed at a boundary between the upper housing 2a and the lower housing 2b. As the heat-sensitive recording material, a sheet-shaped heat-sensitive paper having a heat-sensitive coloring layer having a heat-sensitive coloring property formed on its surface, a heat-sensitive multiplex copy paper 110 (see FIG. 4) in which a plurality of heat-sensitive papers are overlapped, and the like are recorded. Used as a material.

In the vicinity of the paper feed port 8, there is provided a reflection type optical sensor 9 for detecting the thermal recording material inserted in the paper feed port 8. The reflection type optical sensor 9 is arranged so that its output value changes according to the presence or absence of the thermal recording material.

In the housing 2, a substantially U-shaped paper path 1 from the paper feed port 8 to the paper discharge port 6 via the printing unit 10 is provided.
1 is formed. The paper path 11 is linearly communicated from the paper feed port 8 to a lower side of a platen 12 described later, reaches a nip section 15 described later while largely changing the direction along the outer peripheral side of the platen 12, and is discharged from the nip section 15. The paper port 6 is linearly communicated.

The printing unit 10 includes a cylindrical platen 12 that is driven to rotate by a motor (not shown) and a paper path 1 by being urged by an urging member (not shown).
1 and a line-type thermal head 13 which comes into contact with a platen 12 via the first thermal head 1.

The platen 12 also functions as a transport mechanism that applies a transport force to the thermosensitive recording material guided in the paper path 11 by being driven to rotate by a motor. The outer peripheral surface of the platen 12 is covered with an elastic member such as rubber. In the present embodiment, the outer peripheral surface of the platen 12
Although covered by an elastic member such as rubber, the present invention is not limited to this, and the platen 12 itself may be formed by an elastic member such as rubber.

Below the platen 12, a pinch roller 1 urged toward the platen 12 by an urging member (not shown)
4 are provided. The heat-sensitive recording material conveyed to the printing unit 10 is pressed against the platen 12 by a pinch roller 14.

A plurality of heating elements (not shown) arranged in a line are formed at a position (hereinafter referred to as a nip portion) 15 of the thermal head 13 in contact with the platen 12. In the nip portion 15, printing is performed on the thermal multiplex copy paper 110 passing through the nip portion 15. Therefore, in the present embodiment, the nip portion 15 formed by the thermal head 13 and the platen 12 is set as a printing position. I have. Although not particularly shown, the thermal head 13 is mounted so as to be rotatable about a support shaft (not shown), and swings in a direction away from the platen 12 due to the thickness of a thermal recording material guided in the paper path 11. Move.

Further, in the information terminal device 1 of the present embodiment, a rectangular sheet-like film 16 as a regulating member is attached so as to cover the paper discharge port 6. One end of the film 16 is fixed to the housing 2,
The other end of the thermal head 1 extends along the outer surface of the housing 2.
The free end extends from the third side to the platen 12 across the sheet discharge port 6. Also, one end of the film 16 is
It is fixed inside the housing 2. Here, the film 16, the contact portion 2 _L abutting the upper surface of the film 16 of the housing 2, the pressing member is realized.

Incidentally, the film 16 of the present embodiment is
Has a length L of 20 extending along the housing 2.
mm or more. The film 16 of the present embodiment is a colorless and transparent sheet.

In this embodiment, the length L of the portion of the film 16 extending along the housing 2 is 20 mm.
Although formed as described above, the present invention is not limited to this, and depending on the type of thermal multiplex copying paper 110 to be used,
The length L can be changed to any length. The length L of the film 16 in the present embodiment is preferably in the range of about 5 mm to 20 mm in consideration of ease of use and the like.

In addition, although not particularly shown, the information terminal device 1 has a housing 2 in which a battery, a control board on which a microcomputer is mounted, various motors including a motor for rotating the platen 12 described above, and the like are built. I have. The microcomputer includes a CPU for driving and controlling each unit in the information terminal device 1, a ROM for storing a control program and the like,
The power supply switch 3a is turned on by connecting a RAM or the like serving as a work area of the CPU to a bus line.
Power from the battery
Various processes are executed according to the control program. In addition, the microcomputer can receive a key operation from the input unit 3 when power is supplied from the battery.

In such a configuration, a plurality of sheet-like thermal papers 107, 108, and 109 are used as thermal recording materials.
(3 sheets in this case) Superimposed thermal multiplex copy paper 110
A printing operation using (see FIG. 4) will be described.
Thermal paper 107,10 constituting thermal multiplex copying paper 110
Reference numerals 8 and 109 denote binding portions 1 on one side which is on the downstream side in the transport direction.
11 are bound together by glue or the like.

First, the microcomputer is, for example,
Upon receiving the detection signal from the reflection type optical sensor 9, the motor is driven for a predetermined time. As a result, the platen 12 is driven to rotate for a predetermined time, and the leading end of the heat-sensitive recording material is
Is transported until it reaches.

The end of the thermosensitive multiplex copy paper 110 is located at the nip 1
When a predetermined key operation is performed by the operator in a state in which the sheet has been transported to reach the position No. 5, the microcomputer drives a motor (not shown) to rotate the platen 12, and based on the print data stored in the memory. To selectively drive the heating elements of the thermal head 13. As a result, predetermined items are printed on the thermal multiplex copying paper 110.

Here, the external force acting on the heat-sensitive multiplex copying paper 110 when passing through the nip portion 15 will be considered. The thermal head 13 and the top paper 107 are added to the thermal multiplexed copying paper 110 at the time of passing through the nip portion 15.
, Frictional forces μ1, μ2, μ3 are acting between the thermal papers 107, 108, 109, 110 and between the platen and the lowermost paper 109, respectively. Generally, frictional force μ
In the case of 1, μ2, and μ3, the state where the relation of μ1 <μ2 <μ3 is established is an ideal relation in which no sheet gap occurs.

By the way, in the information terminal device 1 described above,
Thermal copy paper 11 only by the transport force of platen 12
Convey 0. At the time of transport, the thermal multiplex copy paper 110 in the nip portion 15 is in contact with the thermal head 13 on which the uppermost paper 107 is fixed, and the lowermost paper 109 is directly under the transport force of the platen 12. . As a result, the uppermost sheet 107 has a greater resistance in the advancing direction than the lowermost sheet 109, and is less likely to advance than the lowermost sheet 109.

Further, in the thermal multiplex copying paper 110, as described above, a wax layer (not shown) is provided between the thermal papers 107, 108 and 109, so that each thermal paper 10
The frictional force μ2 between the thermal papers 7, 108, and 109 tends to be low, and the thermal papers 107, 108, and 109 tend to slip.

If the degree of progress of the single heat-sensitive multiplex copying paper 110 is different between the upper and lower papers, the printing position will be different for each heat-sensitive paper and a paper gap will occur (see FIG. 7), and the printing quality will deteriorate. Resulting in.

In the present embodiment, the nip 15 is provided immediately before the paper exit 6 and the film 16 is provided immediately after the paper exit 6, so that the nip 15 is conveyed into the paper path 11 and As shown in FIG. 3, the heat-sensitive multiplexed copying paper 110 passing through the
6, the thermal head 13 presses against the contact portion 2 _L from the thermal head 13 side, and advances along the outer surface of the housing 2.

As a result, as shown in FIG. 4, the heat-sensitive multiplex copy paper having passed through the nip portion 15 is
5, a force can be applied to the thermal multiplex copying paper 110 to press the thermal multiplex copying paper 110 in the thickness direction. Thereby, each thermal paper 107,
It is possible to prevent the occurrence of a sheet gap between the sheets 108 and 109, and to maintain good print quality on the thermal multiplex copy sheet.

Further, since one end of the film 16 is fixed to the inside of the housing 2, the heat-sensitive multiplex copying paper 110
On the other hand, a force pressing in the thickness direction from the thermal head 13 side can be applied more effectively.

Further, since the film 16 is formed so that the length L extending along the housing 2 is at least 20 mm, the thermal multiplex copying paper 110 after passing through the nip portion 15 is the force to press the head 13 side to the contact portion 2 _L, can be made to act sufficiently to the extent that the paper between the deviation does not occur. Thermal multiplex copy paper 110
The force for pressing the thermal head 13 side to the contact portion 2 _L is the length of the length L is larger than the longer, in this embodiment, in consideration of the length of slips to be issued 20m
because it is the m, it does not hinder the cutting or the like of issued documents while sufficiently by the action of force for pressing the heat-sensitive multiple copying paper 110 from the thermal head 13 side to the contact portion 2 _L.

Further, since the paper path 11 is bent along the outer peripheral surface of the platen 12, the thermal multiplex copying paper 110 conveyed in the paper path 11 moves the thermal head 13 side toward the outer peripheral side at the nip 15. And bend. Multiple thermal copy paper 1 used in information terminal device 1 of the present embodiment
10 are bound together by the binding unit 111, so that the lowermost paper 109 is bound by the binding unit 1 by being bent.
A force acts to draw the uppermost sheet 107 to the platen 12 via the sheet 11. This force, the film 16 acts on the force and substantially the same direction to be impose thermal multiple copy paper 110 to the contact portion 2 _L.

As a result, the paper path 11 is
2, the uppermost sheet 107, which is the outer peripheral side by being bent, is attracted to the platen 12 side, and the film 16 causes the heat-sensitive multiplex copy paper 110 to contact the contact portion 2. It is possible to apply the force to be pressed against the _L in substantially the same direction, and to suppress the occurrence of slip between the thermal papers 107, 108, 109 with a practically simple configuration, It is possible to prevent the gap between the sheets occurring on the downstream side from spreading to the nip portion 15 and to maintain good printing quality on the thermal multiplex copy sheet.

In addition, since the film 16 is formed into a sheet having a width substantially equal to the width of the paper discharge port 6, the thermal multiplex copy paper 110 can be easily compared with the thermal head 13 with a practically simple configuration. , The force pressing in the thickness direction can be made to act more effectively.

In the present embodiment, since the film 16 is formed of a transparent material, a printed matter such as a slip issued from the paper discharge port 6 can be immediately visually recognized by the operator.

[0052]

According to the thermal printer of the first aspect of the present invention, when the thermal multiplex copying paper is transported, the thermal multiplex copying paper that has passed the printing position is moved in the thickness direction so as not to hinder the transport by the pressing member. By pressing down, it becomes possible to apply a pressing force in the thickness direction to the thermal multiplex copying paper after passing through the printing position,
It is possible to prevent misalignment between the thermal papers. This makes it possible to provide a thermal printer having good print quality on thermal multiplex copying paper.

According to the second aspect of the present invention, in the thermal printer according to the first aspect, when the thermal multiplex copying paper is transported, the thermal multiplex copying paper that has passed the printing position is regulated by the regulating member from the thermal head side to the outer surface of the housing. By pressing against the paper, it is possible to apply a pressing force in the thickness direction to the thermal multiplex copying paper after passing the printing position by using the housing, so that the number of parts is not particularly increased. In addition, it is possible to prevent misalignment between the thermal papers. This makes it possible to provide a thermal printer having good print quality on thermal multiplex copying paper.

According to the third aspect of the present invention, in the thermal printer according to the first or second aspect, the thermal multiplex copying paper conveyed in the paper path is bent at the printing section with the thermal head side as the outer peripheral side. Thus, for example, when transporting thermal multiplex copying papers that are bound together by a binding unit provided at least at one end, such as a general slip, it is only necessary to bend the paper path along the outer peripheral surface of the platen. The force to pull the thermal paper on the thermal head side, which is the outer peripheral side by being bent, toward the platen side via the binding portion by the thermal paper, which is the inner peripheral side, and the regulating member causes the thermal multiplex copying paper to move to the housing. Since it is possible to apply a force for pressing against the outer surface in substantially the same direction, it is possible to prevent misalignment between the thermal papers with a practically simple configuration. This makes it possible to provide a thermal printer having good print quality on thermal multiplex copying paper.

According to a fourth aspect of the present invention, in the thermal printer according to the second or third aspect, a force for pressing the thermal multiplex copying paper in the thickness direction from the thermal head side is more effectively applied. Is possible,
The effect described in claim 2 or 3 can be realized more reliably.

According to the invention described in claim 5, according to claim 2,
In the thermal printer according to the third or fourth aspect, the effect of the second, third or fourth aspect is achieved with a practically simple configuration by forming the regulating member into a sheet shape having a width substantially equal to the width dimension of the paper discharge port. Can be realized.

[Brief description of the drawings]

FIG. 1 is a plan view showing an information terminal device according to an embodiment of the present invention.

FIG. 2 is a side view showing a part of the cross section.

FIG. 3 is an enlarged view showing a part thereof.

FIG. 4 is an enlarged view showing a part thereof.

FIG. 5 is a sectional view schematically showing a portable thermal printer.

FIG. 6 is a sectional view showing a part thereof.

FIG. 7 is a cross-sectional view illustrating the occurrence of a sheet shift.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Thermal printer 2 Housing 2 _L , 16 Pressing member 6 Paper discharge port 8 Paper supply port 10 Printing part 11 Paper path 12 Platen 13 Thermal head 16 Regulation member

Continued on front page F term (reference) 2C058 AB16 AC06 AE02 AE10 AF31 AF37 2C059 DD05 DD13 2C065 AA01 AB01 AC04 AF01 CC23 CC24 CC29 CC30 3F101 FB15 FD02 LA07 LB03

Claims (5)

[Claims] 1. A sheet path for guiding a recording material to a predetermined path, a platen provided in the sheet path and driven to rotate, and a thermal contacting the platen with the platen at a printing position via the sheet path. A printing unit having a head, provided in the paper path on the downstream side of the printing unit in the transport direction of the recording material, in the thickness direction such that the transport of the recording material passing the printing position is not hindered. And a pressing member for pressing down on the thermal printer. 2. A housing having a housing shape having a paper feed port and a paper discharge port formed therein, wherein the printing unit is disposed in the housing, and the paper path passes from the paper feed port to the inside of the housing. Then, from the discharge port to the outside of the housing, the pressing member,
A regulating member having one end fixed to the housing and a free end extending from the thermal head side to the platen side along the outer surface of the housing along the outer surface across the paper discharge port; 2. The thermal printer according to claim 1, wherein the thermal printer is constituted by the outer surface of the housing with which a member contacts. 3. The thermal printer according to claim 1, wherein the paper path is bent along an outer peripheral surface of the platen. 4. The thermal printer according to claim 2, wherein said one end of said regulating member is fixed inside said housing. 5. The thermal printer according to claim 2, wherein said regulating member is a sheet-like member having a width substantially equal to a width dimension of said paper discharge port.