JPH0541891Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a serial thermal printer used as an output mechanism for various information processing devices, etc., and in particular to a structure for attaching a thermal head to a carriage. .

[Conventional technology]

In serial thermal printers, the thermal head is mounted on a carriage that moves back and forth along a platen that supports print media such as paper, but since the thermal head is a consumable item, it is not possible to attach or remove it from the carriage. One of the many types is one that allows the thermal head to be attached to and removed from the carriage with a single touch without using any special tools.

Fig. 10 is a perspective view showing a conventional thermal head mounting structure, Fig. 11 is a perspective view showing the structure of the carriage part in Fig. 10, and Fig. 12 is a side cross section of a serial thermal printer having the structure shown in Fig. 10. FIG. 13 is a plan view of the left side thereof.

First, in FIG. 12, 1 is a frame of the printer, 2 is a platen, and the front side of the platen 2 is formed of a flat elastic body 3 such as heat-resistant rubber.
Further, mounting holes are provided at both ends, and by fitting support pins 4 press-fitted into each mounting hole from both sides of the upper part of the frame 1, the frame 1 can be rotated by a certain angle around the support pins 4, which will be described later. It is designed so that it can always come into surface contact with the thermal head.

5 is a thermal head, and this thermal head 5
A flexible cable 6 is connected to the
Drive energy is transmitted from a control means (not shown) through the flexible cable 6.

In addition, as shown in FIG.
is bonded to the heat sink 7 using a protrusion 8 provided on one side of the heat sink 7 as a positioning reference, and two types of protrusions 9 and 10 are provided on both sides of the heat sink 7 in a predetermined positional relationship. There is.

11 is an upper guide shaft, and 12 is a lower guide shaft. Both guide shafts 11 and 12 are supported at both ends of the frame 1 so as to be parallel to each other.

A drive shaft 13 is located between the upper guide shaft 11 and the lower guide shaft 12, and has a spiral groove 14 on its outer peripheral surface.The drive shaft 13 is supported on both sides of the frame 1. It is rotated by a space motor (not shown).

Reference numeral 15 denotes a first carriage, and this first carriage 15 is provided with three holes, and each hole is connected to the guide shafts 11, 12 and the drive shaft 13.
The hole 16 through which the upper guide shaft 11 passes is elongated.

17 is a feed pin attached to the first carriage 15, and the tip of this feed pin 17 is attached to the drive shaft 1.
The drive shaft 1 protrudes into the hole through which 3 passes.
3, so that when the drive shaft 13 rotates, the first carriage 15 can move on the drive shaft 13 due to the action of the feed pin 17 and the groove 14.

In addition, as shown in FIG. 11, the first carriage 15
A protrusion 18 is provided on the back surface, and a cable clamp 19 can be attached to the protrusion 18.

Reference numeral 20 denotes a second carriage, which has two legs 21 at the bottom as shown in FIG. By passing the lower guide shaft 12 through the mounting hole while sandwiching the lower part of the first carriage 15, it is possible to move together with the first carriage 15 and rotate around the lower guide shaft 12. ing.

A rotation hole 22 parallel to the upper guide shaft 11 is provided on the back side of the second carriage 20, and a recess 23 and a mounting groove are provided on the front side, that is, the side facing the platen 2. 2
4, 25 are formed, and the heat sink 7 is inserted into the recess 23 from above, and the protrusions 9, 25 are formed.
The thermal head 5 is held by the second carriage 20 so as to face the platen 2 by fitting the thermal head 10 into the mounting grooves 24 and 25, respectively.

Here, the projection 10 and the mounting groove 25 are fitted together by utilizing the elasticity of the portion in which the mounting groove 25 is formed.
It is detachable from the carriage 20 .

Further, a flexible cable 21 connected to the thermal head 5 is guided to the back side of the first carriage 15 via the lower part thereof, and is latched to the protrusion 18 and fixed by a cable clamp 19.

Reference numeral 26 denotes a spring as a biasing means passed between the front surface of the first carriage 15 and the back surface of the second carriage 20, and the second carriage 20 is constantly pressed in the direction of the platen 2 by this spring 26. This allows the thermal head 5 to come into close contact with the elastic body 3 of the platen 2.

27 is a rotation hole 22 of the second carriage 20.
This is a rotating pin corresponding to the above, and the tip thereof has a conical shape as shown in Fig. 13.

The rotation pin 27 is press-fitted into the rotation hole 22 from one side of the frame 1,
When the thermal head 5 is pressed against the elastic body 3 of the platen 2, the center is positioned a certain amount closer to the first carriage 15 than the center of the rotation hole 22.

28 is a feed roller disposed below the platen 2, whose central shaft 29 is rotatably supported on both sides of the frame 1, and is connected to a line feed motor (also not shown) via a reduction gear train (not shown). ing.

Reference numeral 30 denotes a paper chute arranged along the outer periphery of the feed roller 28;
A plate spring 31 is fixed to the frame 1 by welding or the like, and a printing medium 32 supplied from outside the frame 1 is attached to the frame 1.
is pressed against the feed roller 28 by a leaf spring 31.

Next, the operation of the above-described configuration will be explained.

Now, as shown in FIG. 13A, when the thermal head 5 is in the normal printing stop position a along with the first carriage 15 and the second carriage 20, the thermal head 5 is in close contact with the elastic body 3 of the platen 2. It's summery.

Therefore, when setting the print medium 32, first the drive shaft 1 is set by a space motor (not shown).
3 in a predetermined direction and moved to the left, that is, toward the home position b, under the guidance of the upper guide shaft 11 and lower guide shaft 12, the rotation hole 22 provided in the second carriage 20 opens. It gradually fits into the rotation pin 27 fixed to the frame 1.

As the two are fitted together, the second carriage 20 moves the lower guide shaft 1 so as to separate the thermal head 5 from the elastic body 3 of the platen 2.
2, and when the thermal head 5 reaches the home position b, the rotation of the drive shaft 15 is stopped and the thermal head 5
stops together with the first carriage 15 and the second carriage 20.

At this time, the tip of the rotation pin 27 is completely fitted into the rotation hole 22 as shown in FIG. 13B, so that the thermal head 5 is separated from the elastic body 3 by a certain amount.

In this state, the print medium 32 shown in FIG. 12 is inserted between the feed roller 28 and the paper shoot 30, and pushed until the leading end of the print medium 32 is pressed against the feed roller 28 by the leaf spring 31.

Thereafter, a line feed motor (not shown) is driven to rotate the feed roller 28 together with its center shaft 29 in a predetermined direction, thereby feeding the print medium 3.
2 is loaded between the platen 2 and the thermal head 5, and the rotation of the feed roller 28 is stopped when a certain amount has been loaded.

After setting the printing medium 32 in this way, when printing is to be performed, the drive shaft 13 is rotated in the opposite direction by the space motor.

As a result, the thermal head 5 moves to the right in FIG. 13 together with the first carriage 15 and the second carriage 20, and along with this, the fitting between the rotation hole 22 and the rotation pin 27 is gradually released. Accordingly, the second carriage 20 is rotated by the spring 26 about the lower guide shaft 12 in the opposite direction.

When the position a is reached, the rotation hole 22 is completely removed from the rotation pin 27, and the thermal head 5 is brought into close contact with the elastic body 3 of the platen 2 via the printing medium 32, as shown in FIG. , after that, the thermal head 5 moves further to the right together with the first carriage 15 and the second carriage 20, and moves to the thirteenth carriage.
After passing through the acceleration range shown in FIG. A, the thermal head 5 prints on the print medium 32 in response to the drive energy supplied via the flexible cable 6 in the print range.

When one line of printing is completed, the feed roller 28 is rotated again by the line feed motor, and a line feed is thereby performed on the printing medium 32. This line feed is caused by the thermal head 5 passing through the printing medium 32 to the elastic body 3 of the platen 2. It is carried out in close contact with the

The above describes the conventional serial thermal printer and its thermal head mounting structure.
According to this, there are the following problems.

[Problem that the invention attempts to solve]

In the conventional technique described above, that is, in the thermal head mounting structure shown in FIG. 10, the heat sink to which the thermal head is fixed is inserted into the recess of the second carriage, thereby fixing the heat sink in such a way that the entire heat sink is wrapped around the second carriage. Since the thermal head is thereby fixed to the second carriage, the width of the second carriage is wider than the width of the heat sink.

Therefore, the space required for moving the carriage must be increased in proportion to the width, and the printer becomes wider, which poses a problem in making the printer more compact.

On the other hand, if you try to secure the necessary printing width within a limited width, the width of the thermal head, heat sink, second carriage, etc. will be limited, but with conventional structures, it is impossible to reduce these widths. Have difficulty.

The present invention was developed to solve these problems, and the object is to realize a thermal head mounting structure that allows the width of the carriage to be smaller than that of the thermal head, thereby making it possible to downsize the printer. It is.

[Means for solving the problem] In order to achieve the above-mentioned object, the present invention fixes a thermal head to a heat sink, and connects the thermal head via the heat sink to a carriage that moves parallel to a platen that supports a print medium. In the thermal head mounting structure of the printer to which the thermal head is mounted, the heat sink has two mounting grooves on the back side with the cross-sectional shape being roughly E-shaped, with the open surfaces facing opposite directions, and both mounting grooves are provided. A fixing protrusion that protrudes toward the open surface side is provided in the groove, and a protrusion that serves as a positioning reference for the thermal head is provided on one front side of the heat sink, and the thermal head has one side thereof attached to the protrusion. The carriage is made of an elastic material and has a width equal to or less than the width of the heat sink, and is fitted with the portion between the mounting grooves and the fixing protrusion to secure the heat sink. It is characterized by having one notch that holds it in a locked state.

[Effect]

In the present invention having the above-described configuration, the thermal head is fixed to the front of the heat sink by abutting one side of the thermal head against the protrusion, and the portion between the mounting grooves of the heat sink and the fixing protrusion utilizes the elasticity of the carriage. When the heat sink is fitted into the notch, the heat sink is held locked to the carriage due to the engagement between the notch and the fixing protrusion.

Therefore, compared to the conventional structure in which the entire heat sink is wrapped around and fixed in a carriage, the width of the carriage can be made equal to or less than the width of the heat sink, which reduces the space required to move the carriage. Since the heat sink can be made smaller, it is possible to make the printer more compact, and the heat sink is held in a locked state in the carriage by the heat sink notch and the fixing protrusion, so the thermal head can be attached with a simple structure. This allows for reliable installation.

In addition, the thermal head is fixed to the front of the heat sink by aligning one side with a protrusion that serves as a positioning reference provided on one side of the front of the heat sink, so when the heat sink is attached to the carriage, the position remains constant. Even if the thermal head is replaced, there is no need to adjust the initial position during printing.

〔Example〕 Examples will be described below with reference to the drawings.

Figure 1 is a perspective view showing the thermal head mounting structure of a printer according to the present invention, Figure 2 is a diagram showing the relationship between the thermal head and the heat sink, Figure 3 is a side view of Figure 2, and Figure 4 is the 5 is a perspective view of the platen in FIG. 4, FIG. 6 is a cross-sectional plan view of the left side in FIG. 4, and FIG.
8 is a partially enlarged view of FIG. 4, and FIG. 9 is a view taken along arrow E in FIG. 8.

First, in FIG. 4, reference numeral 33 denotes a frame of the printer. This frame 33 is made of elastic resin, and as shown in FIG. and a support hole 35 are provided, and a support hole 36 corresponding to the other side of the platen is provided on the other side.

Reference numeral 37 denotes a platen, and the front side is made of a flat elastic body 38 such as heat-resistant rubber, which is the same as in the past. A support shaft 42 is formed which has a protrusion 39 projecting from above and flanges 40 and 41 projecting in the opposite direction to the protrusion 39, and a substantially columnar support shaft 43 is formed on the other side. Fit the shaft 43 into the support hole 36, and insert the support shaft 42 through the insertion hole 34 to insert it into the support hole 3.
6, the platen 37 is supported so as to be rotatable at a certain angle so that the platen 37 can come into surface contact with a thermal head, which will be described later, at the surface of the elastic body 38.

Note that the flanges 40 and 41 prevent the platen 32 from moving in the left-right direction.

44 is a thermal head, and a flexible cable 45 is connected to this thermal head 44 as shown in FIGS. 1 to 3, so that drive energy is transmitted from a control means (not shown).

Reference numeral 46 denotes a heat sink having a roughly E-shaped cross-sectional shape, and as shown in FIGS.
A book mounting groove 47 is formed, and fixing protrusions 48 that protrude toward the release surface are formed in both mounting grooves 47, and a protrusion that serves as a positioning reference is formed on one front side. A portion 49 is formed, and the thermal head 44 is adhesively fixed to the heat sink 46 with one side abutted against this protrusion 49.

50 is an upper guide shaft, 51 is a lower guide shaft, and both ends of the guide shafts 50 and 51 are supported on both sides of the frame 33 so as to be parallel to each other.

A drive shaft 52 is located between the upper guide shaft 50 and the lower guide shaft 51, and has a spiral groove 53 on its outer peripheral surface, and the drive shaft 52 is supported on both sides of the frame 33. It is rotated by a space motor (not shown).

54 is a first member made of elastic resin.
As shown in FIG. An engagement groove 55 is provided at the lower part.

56 is a feed pin attached to the first carriage 54, and the tip of this feed pin 56 is connected to the drive shaft 5.
2 projects into the hole through which it engages with the groove 53 of the drive shaft 52, so that when the drive shaft 52 rotates, the first carriage 54 is moved onto the drive shaft 52 by the action of the feed pin 56 and the groove 53. can be moved.

57 is a projection provided on the back surface of the first carriage 54, and 58 is a cable clamp.

59 is a second carriage made of elastic resin similar to the first carriage 54;
As shown in FIG.
1 sandwiching the lower part of the first carriage 54, the rib 6
0 into the engagement groove 55 of the first carriage 54, there is almost no rattling in the left and right directions, and the first carriage 54 can be moved in the vertical direction. By passing the lower guide shaft 51 through the lower guide shaft 51 in series, it is possible to reciprocate along the front surface of the platen 37 together with the first carriage 54, and to move in a direction facing the front surface of the platen 37 with the lower guide shaft 51 as the center. It is now possible to rotate.

In addition, a notch 62 is formed in the center of the second carriage 59, which corresponds to the portion between the mounting grooves 47 of the heat sink 46 and the fixing protrusion 48. By fitting the fixing protrusion 49 into the notch 62, the thermal head 44 is attached to the elastic body 38 of the platen 37.
It is removably fixed and held so that it faces the.

Here, the fixing protrusion 48 and the notch 62 are fitted together using the elasticity of the second carriage 59, but with such a structure,
The width of the heat sink 4 relative to the width of the thermal head 44
6 and the first and second carriages 54, 59 can be reduced in width, making it possible to design them compactly.

Further, as shown in FIG. 2, by utilizing the shape of the heat sink 46, it is possible to mount thermal heads 44 of, for example, 16 elements and 26 elements on the heat sink 46 of the same size, and the center of the heat sink 46 and the element part of the thermal head 44 can be mounted. By keeping the dimension l constant, the first carriage 54, second carriage 59, and heat sink 46 can be used as common parts for two or more types of printers without having to correct the home position or printing position. It is also possible to do so.

The flexible cable 45 connected to the thermal head 44 is led to the rear side of the first carriage 54 via the lower part thereof, and is locked by a protrusion 57 and fixed by a cable clamp 58.

Reference numeral 63 denotes an arm portion formed to protrude from one side of the second carriage 59 toward the protrusion 39 formed on the support shaft 42 of the platen 37. The front surface of this arm portion 63 is such that the thermal head 44 is attached to the platen 37.
The arm portion 63 is set to be in a position closer to the elastic body 38 than the distal end surface of the protrusion 39 when it comes into close contact with the elastic body 38 , and the protrusion length of the arm portion 63 is set to be close to the second carriage together with the thermal head 44 . 5
9 is located at the home position b, the front portion has a length such that it rides on the tip end surface of the protrusion 39.

Reference numeral 64 denotes a spring as a biasing means passed between the front surface of the first carriage 54 and the rear surface of the second carriage 59. This spring 64 always applies an appropriate force to the second carriage 59 in the direction of the platen 37. This causes the thermal head 44 to come into close contact with the elastic body 38 of the platen 37.

65 is a feed roller disposed below the platen 37, and its central axis 66 is connected to the frame 33.
It is rotatably supported on both sides of the motor, and is connected to a line feed motor, also not shown, via a reduction gear train, not shown.

A paper chute 67 is arranged along the outer periphery of the feed roller 65 and is fixed to the frame 33.

A leaf spring 6 is attached to the bottom side of this paper shoot 67.
8 is fixed in a pretensioned state by welding or the like, and FIGS.
As shown in the figure, a shaft 71 of a pressure roller 70 is rotatably held in a bearing portion 69 formed by bending a part of a paper shoot 67, and the pressure roller 70 is connected to a feed roller by a leaf spring 68 via this shaft 71. 65.

The pressure roller 70 is disposed diagonally below the feed roller 65 at a position of about 45 degrees.

Next, the operation of the printer configured as described above will be explained.

First, as shown in FIG. 6A, the first carriage 5
When the thermal head 44, together with the fourth and second carriages 59, is in the normal printing position a, the thermal head 44 is in close contact with the elastic body 38 of the platen 37.

Therefore, when setting the print medium 32, first the drive shaft 5 is moved by a space motor (not shown).
2 is rotated in a predetermined direction and moved to the left, that is, toward the home position b, under the guidance of the upper guide shaft 50 and the lower guide shaft 51. The medium gradually rides on the protrusion 39 provided on the support shaft 42 of 37 and located outside the medium passage range.

Along with this climbing operation, the arm portion 6
3 is pushed by the protrusion 39, the second carriage 59 rotates around the lower guide shaft 51 so as to separate the thermal head 44 from the elastic body 38 of the platen 37, and the thermal head 44
When the thermal head 44 reaches the home position b and is detected by a detection means such as a micro switch (not shown), the rotation of the drive shaft 52 is stopped and the thermal head 44 moves to the home position along with the first carriage 54 and the second carriage 59. Stop at section b.

At this time, the arm portion 63 completely rides on the protrusion 39 as shown in FIG. 6B, and as a result, the thermal head 44 is separated from the elastic body 38 by a certain amount, creating a gap (platen gap) G as shown in FIG. At the same time, the platen 37 is held unrotatable by the pressure of the protrusion 39 and the arm 63 against each other.

In this state, when the print medium 32 shown in FIG. 4 is inserted between the feed roller 65 and the paper chute 67 and pushed in, the leading edge of the print medium 32 will easily slide along the R of the paper chute 67 and between the feed roller 65 and the pressure roller 70. It reaches the pressure welding part.

Thereafter, a line feed motor (not shown) is driven to rotate the feed roller 65 together with its central shaft 66 in a predetermined direction, thereby feeding the print medium 3.
2 is loaded between the platen 37 and the thermal head 44, and the rotation of the feed roller 65 is stopped when a certain amount has been loaded.

After setting the printing medium 32 in this way, when printing is to be performed, the drive shaft 52 is rotated in the opposite direction by the space motor.

As a result, the thermal head 44 moves integrally with the first carriage 54 and the second carriage 59 to the right in FIG. The carriage 59 is rotated by the spring 64 about the lower guide shaft 51 in the opposite direction.

When the arm portion 63 reaches the position a, the arm portion 63 is completely separated from the protrusion 39, and the thermal head 44 is brought into close contact with the elastic body 38 of the platen 37 via the print medium 32, as shown in FIG. Thereafter, the thermal head 44 is connected to the first carriage 54 and the second carriage.
After moving further to the right with the carriage 59 and passing through the acceleration range shown in FIG. During printing, even if the first carriage 54 is tilted, the second carriage 59
The legs 61 of the book are integrated by the ribs 60, so they will not open.

When one line of printing is completed, the feed roller 65 is rotated again by the line feed motor, thereby performing a line feed on the print medium 32. This line feed is caused by the thermal head 44 moving through the print medium 32 to the elastic body 38 of the platen 2. It is carried out in close contact with the

One embodiment of the present invention has been described above, but
The present invention is not limited to this.

For example, in the above-mentioned embodiment, the carriage is divided into the first carriage 54 and the second carriage 59, and the thermal head 44 is attached to the second carriage 59, but the thermal head 44 can also be attached to a single carriage. Of course it is possible.

[Effect of idea]

As explained above, the present invention provides a heat sink having a roughly E-shaped cross-sectional shape and having two mounting grooves on the back side with their open surfaces facing in opposite directions, and the two mounting grooves having the above-mentioned openings in both mounting grooves. The heat sink has a structure in which it has a fixing protrusion that protrudes from the surface side, and a protrusion that serves as a positioning reference for the thermal head on one front side of the heat sink, and the thermal head has one side abutted against the protrusion. The carriage is fixed to the heat sink, and the carriage is made of an elastic material and has a width equal to or less than the width of the heat sink, and is fitted with the portion between the mounting grooves and the fixing protrusion to lock the heat sink. It has a structure with one notch for holding.

Therefore, compared to the conventional structure in which the entire heat sink is wrapped around and fixed in a carriage, the width of the carriage can be made equal to or less than the width of the heat sink, which reduces the space required to move the carriage. Since the heat sink can be made smaller, it is possible to make the printer more compact, and the heat sink is held in a locked state in the carriage by the heat sink notch and the fixing protrusion, so the thermal head can be attached with a simple structure. This has the effect of making it possible to securely install the.

In addition, because the thermal head is fixed to the front of the heat sink by aligning one side with a protrusion that serves as a positioning reference provided on one side of the front of the heat sink, the position will be constant when it is attached to the carriage via the heat sink. Therefore, even if the thermal head is replaced, there is no need to adjust the initial position during printing.

In addition, by keeping the dimensions of the center of the heat sink and the element part of the thermal head constant with the protrusion of the heat sink as a reference, the home position and printing position can be adjusted without changing the home position or printing position for thermal heads with different numbers of elements. It becomes possible to use the heat sink and the carriage as common parts, and there is also the effect of increasing versatility.

[Brief explanation of drawings]

Figure 1 is a perspective view showing the thermal head mounting structure of a printer according to the present invention, Figure 2 is a diagram showing the relationship between the thermal head and the heat sink, Figure 3 is a side view of Figure 2, and Figure 4 is the 5 is a perspective view of the platen in FIG. 4, FIG. 6 is a cross-sectional plan view of the left side in FIG. 4, and FIG.
8 is a partially enlarged view of FIG. 4, FIG. 9 is a view taken along arrow E in FIG. 8, FIG. 10 is a perspective view of the conventional example, and FIG. 11 is a view of FIG. FIG. 12 is a side sectional view of a serial thermal printer equipped with a conventional example; FIG.
The figure is a plan view of the left side in FIG. 12. 44...Thermal head, 46...Heat sink, 47...Mounting groove, 48...Fixing protrusion, 49
...Protrusion, 54...First carriage, 59...
Second carriage, 62...notch portion.

Claims (1)

[Claims for Utility Model Registration] A thermal head mounting structure for a printer in which a thermal head is fixed to a heat sink and the thermal head is mounted via the heat sink to a carriage that moves parallel to a platen that supports a print medium, comprising: The heat sink has a roughly E-shaped cross-sectional shape and has two mounting grooves on the back side with their open surfaces facing in opposite directions, and a fixing protrusion that protrudes toward the open surface in both mounting grooves. and a protrusion serving as a positioning reference for the thermal head on one front side of the heat sink, the thermal head is fixed to the heat sink by abutting one side of the thermal head against the protrusion, and the carriage has an elastic The heat sink is made of a material having a width equal to or less than the width of the heat sink, and has one notch that fits into the portion between the mounting grooves and the fixing protrusion to hold the heat sink in a locked state. A printer thermal head mounting structure characterized by: