JP3840402B2 - Thermal printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermal printer, and more particularly to a thermal printer capable of performing thermal printing by coloring thermal paper.
[0002]
[Prior art]
As shown in the schematic plan view of FIG. 4, the conventionally proposed thermal printer has a frame 21, and a pair of side plates 21 a facing each other are formed above and below the frame 21.
A cylindrical platen roller 22 is rotatably supported between the pair of side plates 21a.
[0003]
The platen roller 22 has a rotating shaft 23 that protrudes in the vertical direction in the figure, and the rotating shaft 23 can be supported on a shaft support portion 21b formed on a pair of side plates 21a via a bearing 23a.
As shown in FIG. 5, the shaft support portion 21b is substantially U-shaped by opening the upper side of the side plate 21a, and the rotation shaft 23 is attached to the U-shaped shaft support portion 21b so that the shaft support portion 21b can be supported. Yes.
A head mounting base 25 to which the thermal head 24 is fixed is disposed on the left side of the platen roller 22 in the figure. The head mounting base 25 is elastically biased toward the platen roller 22, so that the thermal head 24 is moved to the platen roller 22. It comes to come into pressure contact with.
Locking members 26 and 26 are provided outside the pair of side plates 21a (upper and lower sides in the drawing) for preventing the rotation shaft 23 attached to the shaft support portion 21b from coming off.
[0004]
As shown in FIG. 5, the locking member 26 is formed with an inclined surface 26a that can be prevented from coming off by pressing the rotating shaft 23 attached to the shaft support portion 21b on one side, and a support pin attached to the side plate 21a on the other side. 27 is rotatably supported.
The locking member 26 is elastically biased upward, and the rotating shaft 23 attached to the shaft support portion 21b is pressed against the inclined surface 26a by this elastic force so that it is prevented from coming off from the shaft support portion 21b. It has become.
[0005]
Further, the platen roller 22 with the rotation shaft 23 prevented from coming off from the shaft support portion 21b is rotated by the rotation of a motor or the like transmitted from the outside.
Then, the thermal paper (not shown) is conveyed between the platen roller 22 and the thermal head 24 that are in pressure contact with each other, and a plurality of heating elements (not shown) of the thermal head 24 are caused to generate heat. It is possible to print images such as letters by coloring.
[0006]
[Problems to be solved by the invention]
However, the conventional thermal printer as described above has a problem that since the locking member 26 is disposed outside the side plate 21a, the width dimension A becomes large and the recent requirement for small size cannot be satisfied.
The present invention has been made in view of the above-described points. The thickness of the locking member that pivotally supports the platen roller on the side plate is equal to or less than the thickness of the side plate, and the locking member is disposed within the thickness range of the side plate. It is an object of the present invention to provide a thermal printer which is disposed and has a reduced width.
[0007]
[Means for Solving the Problems]
As a first means for solving the above problems, a thermal printer of the present invention includes a thermal head, a platen roller to which the thermal head can be pressed, and a frame that supports the thermal head and the platen roller, The platen roller has a rotating shaft that can be rotatably supported on the frame. The rotating shaft can be supported on a shaft supporting portion of a pair of side plates formed on the frame, and the shaft supporting portion is open on one side. A locking member that is formed in a substantially U-shape and that can be prevented from coming off the shaft support by pressing the rotating shaft attached to the shaft support from the one side , A state in which a pressing surface capable of pressing the rotating shaft attached to the shaft support portion is formed on one side, and a rotation fulcrum formed on the other side can be turned as a fulcrum, and the rotation shaft is attached to the shaft supporting portion. When operated to rotate the locking member in a direction to close the opening portion in the U-shape, the rotary shaft is rotatably supported in a pressed the shaft support and the pressing surface, the plate thickness of the locking member Is equal to or less than the plate thickness of the side plate, and the locking member is disposed within the plate thickness range of the side plate.
[0009]
Further, as a second means for solving the above-mentioned problem, the locking member is configured to open the U-shaped portion in a direction in which the rotating shaft is pivotally supported on the pivotal support portion by the locking member. When the member is rotated, the retaining of the rotating shaft is released, and the platen roller is pressed by the thermal head and can be discharged from the shaft support portion.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the thermal printer of the present invention will be described with reference to FIGS. FIG. 1 is a plan view of the thermal printer of the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a schematic view for explaining the operation of the locking member according to the present invention.
[0011]
First, an embodiment of the thermal printer according to the present invention will be described with reference to FIG. 1. A frame 1 made of a resin material or the like is provided, and a pair of side plates 1a and 1a are opposed to each other. Is formed.
[0012]
As shown in FIG. 2, the pair of side plates 1a and 1a is formed with a shaft support portion 1b that can support the rotating shaft 3 via a bearing 3a described later. The shaft support portion 1b is formed in a substantially U shape by opening one side on the upper right side in the figure.
The dimension of the portion opened in the U-shape is formed as a dimension B, and a rotation shaft 3 of a platen roller 2 described later can be pivotally supported via a bearing 3a.
The dimension between the pair of side plates 1a and 1a is such that the dimension from the outer surface 1c to the outer surface 1c is C.
[0013]
Further, between the pair of side plates 1a and 1a, a platen roller 2 having a main body portion 2a formed in a columnar shape and formed of a member having a large friction coefficient such as rubber on the outer peripheral portion is positioned.
The platen roller 2 projects from the main body portion 2a in the longitudinal direction from both end surfaces in the vertical direction in the figure, and a rotation shaft 3 is formed. The rotary shaft 3 can be mounted on the shaft support portion 1b from a portion opened in a U-shape having a dimension B via a bearing 3a.
For this purpose, the platen roller 2 is detachable from the shaft support 1b.
[0014]
On the left side of the platen roller 2 in the figure, a thermal head 4 capable of being pressed against the platen roller 2 is fixedly disposed on the head mounting base 5.
The head mounting base 5 is supported by a bottom plate (not shown) of the frame 1 on the lower side, and is elastically urged in the direction of arrow D by an urging member (not shown).
When the head mounting base 5 is elastically biased in the direction of the arrow D as described above, the thermal head 4 can be brought into pressure contact with the outer peripheral portion of the platen roller 2 with a predetermined pressure.
[0015]
Further, as shown in FIG. 2, a locking member 6 having a substantially L shape that can open and close a U-shaped portion having a dimension B formed on the side plate 1 a is disposed.
The locking member 6 has a plate thickness dimension equal to or less than the plate thickness dimension of the side plate 1a, and the locking member 6 is disposed within the plate thickness range of the side plate 1a. Therefore, the width dimension of the thermal printer of the present invention can be made smaller than the conventional width dimension A.
In addition, the locking member 6 is formed with an inclined pressing surface 6a on one side on the right side of the figure through which the rotating shaft 3 can be pressed against the shaft support 1b in the direction of arrow E via a bearing 3a.
For this purpose, the pressing surface 6a prevents the platen roller 2 pivotally supported on the pivotal support 1b from coming off.
[0016]
Further, a round hole-shaped rotation fulcrum 6b is formed on the other left side of the locking member 6 in the figure. The rotation fulcrum 6b is attached by being fitted to a support pin 7 attached to the lower side of the head mounting base 5.
Then, the locking member 6 that supports the rotation fulcrum 6b on the support pin 7 is applied with the urging force of the arrow F from the lower side, and the pressing force of the arrow E is applied to the pressing surface 6a. .
Therefore, the rotary shaft 3 supported by the shaft support portion 1b is supported by the pressing force indicated by the arrow E through the bearing 3a so that the rotation shaft 3 is prevented from being detached from the shaft support portion 1b. Yes.
Further, the rotating shaft 3 at this time is rotatable within a bearing 3a held by the shaft support portion 1b. The rotating shaft 3 can rotate even when a driving force such as a motor is applied from the outside even when the thermal head 4 is in pressure contact with the urging force of the arrow D.
[0017]
Further, when the platen roller 2 is taken out from the shaft support portion 1b for maintenance or the like, as shown in FIG. 3, from the state shown in FIG. 2, the portion where the locking member 6 is opened in the U shape of the shaft support portion 1b is removed. When it is rotated in the opening direction, the retaining shaft of the rotating shaft 3 with the bearing 3a attached thereto is released.
At the same time, the platen roller 2 is pressed by the thermal head 4 urged in the direction of arrow D so that the platen roller 2 can be ejected from the shaft support portion 1b in the direction of arrow H.
That is, the locking member 6 is rotated in the direction (arrow G direction) in which the U-shaped part is opened while the rotary shaft 3 is pivotally supported by the shaft support 1b via the bearing 3a. When the moving operation is performed, the retaining of the rotating shaft 3 is released via the bearing 3a, and the platen roller 2 is pressed by the thermal head 4 and can be discharged from the shaft support portion 1b.
[0018]
Such a thermal printer of the present invention conveys thermal paper (not shown) between the platen roller 2 and the thermal head 4 that are in pressure contact with each other, and a plurality of heating elements (not shown) of the thermal head 24. By selectively generating heat based on the print information, the thermal paper can be selectively colored to print images such as characters. Further, since no components are attached to the respective outer surfaces 1c of the pair of side plates 1a, the width C can be made smaller than the width A of the conventional thermal printer, and the size can be reduced. .
[0019]
Further, in the description of the embodiment of the present invention, the locking member 6 is formed to be equal to or less than the thickness of the side plate 1a and is positioned within the thickness range of the side plate 1a. The member 6 may be disposed so as to be located inside the outer surface 1c of the side plate 1a.
In addition, the bearing 3a is attached to the rotating shaft 3 of the platen roller 2, and the rotating shaft 3 is supported on the shaft support 1b via the bearing 3a. However, the rotating shaft 3 includes the bearing 3a. The rotating shaft 3 may be directly held on the shaft support 1b without being mounted.
That is, the rotary shaft 3 may be one that can be pivotally supported by the pivotal support portions 1 b of the pair of side plates 1 a formed on the frame 1.
[0020]
【The invention's effect】
As described above, the thickness of the locking member according to the present invention is equal to or less than the thickness of the side plate, and the locking member is disposed within the thickness range of the side plate. The width dimension can be reduced by the thickness of the locking member without protruding.
[0021]
Further, when the locking member is rotated in a direction in which the portion opened in the U-shape is closed in a state where the rotation shaft is mounted on the shaft support portion, the rotation shaft is pressed by the pressing surface and is supported by the shaft support portion. Therefore, when performing maintenance or the like, the platen roller can be easily attached and detached, and the workability is good.
[0022]
In addition, when the locking member is rotated in a direction to open the U-shaped portion in a state where the rotating shaft is prevented from being detached from the shaft support portion by the locking member, the retaining of the rotating shaft is released. Since the platen roller is pressed by the thermal head and can be discharged from the shaft support portion, a thermal printer in which the platen roller can be easily attached and detached can be provided.
[Brief description of the drawings]
FIG. 1 is a plan view illustrating a thermal printer of the present invention.
FIG. 2 is a side view of FIG.
FIG. 3 is a schematic view for explaining the operation of the locking member according to the present invention.
FIG. 4 is a plan view of a conventional thermal printer.
FIG. 5 is a side view of FIG. 4;
[Sharpness of sign]
DESCRIPTION OF SYMBOLS 1 Frame 1a Side plate 1b Shaft support part 2 Platen roller 3 Rotating shaft 4 Thermal head 5 Head mounting plate 6 Locking member 6a Pressing part 6b Rotation fulcrum 7 Support pin

Claims (2)

A thermal head, a platen roller to which the thermal head can be pressed, and a frame that supports the thermal head and the platen roller;
The platen roller has a rotation shaft that can be rotatably supported on the frame, and the rotation shaft can be supported on a shaft support portion of a pair of side plates formed on the frame. A locking member that is formed in an open substantially U-shape and that presses the rotating shaft attached to the shaft support portion from the one side and can be prevented from coming off from the shaft support portion is provided. A state in which a pressing surface capable of pressing the rotating shaft mounted on the shaft support portion is formed on the one side, the rotation shaft formed on the other side is rotatable as a fulcrum, and the rotation shaft is mounted on the shaft supporting portion. Then, when the locking member is rotated in a direction to close the U-shaped open portion, the rotating shaft is pressed by the pressing surface and is pivotally supported by the shaft support portion, and the plate of the locking member The thickness is equal to or less than the plate thickness of the side plate and is within the plate thickness range of the side plate. Thermal printer characterized by being provided with the locking member. When the locking member is pivoted in a direction to open the U-shaped open portion while the rotating shaft is pivotally supported by the locking member, the retaining shaft of the rotating shaft is prevented. 2. The thermal printer according to claim 1, wherein the thermal printer is released and the platen roller is pressed by the thermal head and can be discharged from the shaft support portion.

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