JPH0411796Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

This invention relates to an improved thermal head that allows easy connection of the connection terminal section of the external connection board and the input terminal section of the head board side, stabilizes assembly accuracy, and improves workability. .

[Prior Art and its Problems] The basic structure of a thermal head is shown in FIGS. 3 and 4. A heat generating resistor 2, a driver circuit 3 for the heat generating resistor 2, and a comb-shaped input terminal portion 3a for supplying power or control signals to the driver circuit are provided on a base substrate 1 having a screw hole 1a. A head board 4 having a head board 4 is attached with predetermined positioning by adhesion or the like, and an external connection board 5 is superimposed on the base board 1 and head board 4. This external connection board 5 includes a translucent synthetic resin film 7 having a comb-shaped connection terminal portion 6a corresponding to the input terminal portion 3a on one side of the back surface, and a translucent synthetic resin film 7 disposed below the film 7. A reinforcing plate 8 is provided, and a screw through hole 5a corresponding to the screw hole 1a of the base substrate is bored across the film 7 and the reinforcing plate 8. The terminal section 6a on the external connection board 5 side and the input terminal section 3a on the head board 4 side are brought into contact with each other by overlapping the external connection board 5 on the base board 1 or the head board 4. I am made to do so. A protective cover 9 is further stacked on the external connection board 5, and this protective cover 9 has a bent protective plate 1 whose one edge extends beyond the driver circuit 3 to the upper surface of the head board 4.
0, and a pressing plate 11 whose distal edge is overlapped and connected to the proximal edge of the protective plate 10. This presser plate 11 has screw holes 11a that correspond to the screw holes of the base substrate 1 or the screw holes 5a of the external connection substrate 5. Then, the base board 1, the external connection board 5, and the protective cover 9.
This means that the mounting screws 12 are connected to each other through the screw holes 11.
By being screwed into the screw hole 1a through holes a to 5a, they are crimped and fixed to each other. In the figure, reference numeral 13 indicates the input signal connection circuit section of the thermal head, and 14a indicates the holding plate 11 and the external connection board 5.
A spacer 14b interposed between the connecting terminal section 6a and the input terminal section 3a on the head board
15 is a coating agent for protecting the driver circuit 3, 16 is thermal paper, and 17 is a platen for driving the thermal paper. By the way, in assembling the thermal head, first, the external connection board 5 is placed on the base board 1 on which the head board 4 is integrally positioned and mounted.
However, the driver circuit input terminal section 3a and the connection terminal section 6
and a are overlapped so that they correspond to each other and overlap. At this time, in order to adjust the overlapping position of the two, it was necessary to visually check the overlapping condition of the terminal portions of both from the translucent film side and manually adjust the misalignment between the two. Moreover, even if the external connection board 5 is superimposed on the base board 1 at an appropriate position in this way, the external force caused by tightening the screws when attaching the protective cover 9 thereon may cause the two to overlap. Often out of position,
In that case, the position must be adjusted again. Also, during screw tightening work, the screws must be tightened uniformly in each part while checking the overlapping position of the head board side terminal part 3a and the external connection board side terminal part 6a so that they do not shift. Therefore, assembly work requires a great deal of skill, and product accuracy varies due to subtle installation errors caused by differences in the skill of each worker. Conventionally, the above-mentioned problems have been a major obstacle in automating assembly. In addition, since the work is complicated, it takes time to complete the assembly, resulting in a reduction in production efficiency. This idea was devised under the above circumstances, and aims to provide a thermal head that can stabilize product accuracy, facilitate automation of assembly, and shorten assembly time. That is the issue.

[Means to solve the problem]

In order to solve the above problems, this invention adopts the following technical means. That is, the present invention has a base board on which a head board having a driver circuit, its input terminals, and a heat generating resistor is positioned and bonded in a predetermined manner on the front surface, and a back surface corresponding to the input terminal part on one side. an external connection substrate that has a connection terminal portion and is superimposed on the base substrate so that the connection terminal portion is pressed into contact with the input terminal portion; and a protection that is further superposed on the external connection substrate. In the thermal head, the base board, the external connection board, and the protective cover are fixed to each other by a plurality of screws in a superposed state, the base board, the external connection board, and the protective cover, The present invention is characterized in that at least two positioning holes are provided in each of the three members, through which the separate insertable and removable rod-shaped positioning means can be inserted in communication with each other in a predetermined fit while defining the relative position in a plane between the three members. .

[Functions and effects of the idea]

When the rod-shaped positioning means is inserted into the base board, the external connection board, and the protective cover in communication, the input terminals on the head board and the connection terminals on the external connection board are accurately overlapped, and Positioning holes are formed in such a manner that the protective cover presses the overlapping connection terminal portions from above at appropriate positions as described above. Therefore, the work procedure for installation is as follows:
It can be done as follows. First, at least two pins, which are rod-shaped positioning means, are provided protruding from a plate-shaped jig or the like at a predetermined interval, and each positioning hole is fitted into each of these rod-shaped positioning means, and the base board and the external connection board are connected. , and overlay the protective cover. In this state, the base board, external connection board, and protective cover are not fixed, but these three
The relative positions of the two members in the plane direction are determined to be predetermined positions. In other words, by simply overlapping the input terminals as described above, the input terminals on the head board and the connection terminals on the connection board can be accurately connected, even though both have a comb-like shape with a relatively fine pitch. Predetermined terminals are polymerized together. The protective cover is positioned so as to come into contact with the connection board with an appropriate pressing force and to achieve appropriate pressure contact between the two terminals. In this state, for example, screw the screw into the screw hole on the base board while passing through the screw through hole of the protective cover and the external connection board. Of course, the planar positions of these screw holes and screw holes are adjusted so that the screws can be inserted or screwed together. When tightening screws,
In the final stage of screw tightening, a force acts to rotate the protective cover clockwise around the screw shaft, but in the present invention, the rod-shaped positioning means inserted in communication with each positioning hole as described above is at least Since two screws are used, such rotation of the protective cover does not occur, and therefore, displacement of the three overlapping members due to screw tightening cannot occur. In this way, when the above three members, that is, the base board, the external connection board, and the protective cover are fixed to each other by tightening the plurality of screws, the plate-shaped jig is pulled out downward. The rod-shaped positioning means is removed from each positioning hole. As described above, in the present invention, positioning for connection between the input terminal section on the head board, which is integrally bonded to the base board, and the terminal section on the external connection board side is performed via the rod-shaped positioning means. This will be done automatically, so while looking through the film of the external connection board in the conventional example, connect the base board or head of the external connection board so that the terminal parts of both of the above are in an appropriate connection state. The troublesome work of adjusting the degree of overlap with the substrate is omitted. Further, the planar positioning of the protective cover with respect to the external connection board is also automatically performed via the rod-shaped positioning member. Furthermore, since the rotational position shift between the external connection board and the protective cover due to the load of external force during screw tightening work etc. is avoided, the overlapping position of the base board, external connection board, and protective cover after the screw tightening work is avoided. The confirmation work is also omitted. As a result of the above, the efficiency of assembling the thermal head is greatly improved, and even an unskilled person can easily assemble it. Furthermore, the occurrence of installation errors between products is also avoided, product accuracy is uniformly stabilized, and the assembly process can be easily automated. In addition, the rod-shaped positioning means in the present invention is removed from the positioning holes of each member after the work of connecting the base board, external connection board, and protective cover with screws is completed.
For example, the occurrence of thermal stress caused by a difference in thermal expansion coefficient between the base substrate and the protective cover can be alleviated.

[Explanation of Examples]

Hereinafter, embodiments of this invention will be described in detail with reference to the drawings. A preferred embodiment of this invention is shown in FIGS. 1 and 2.
As shown in the figure. As is clear from FIG. 1, the thermal head of this example consists of three members that are superposed on each other:
That is, the base board 1, the external connection board 5, and the protective cover 9 have positioning holes 18,
19 and 20 are provided, the other configuration is the same as the conventional example shown in FIGS. 3 and 4. Note that these positioning holes 18, 19,
20, the positioning holes 18 and 19 provided in the base board 1 and the external connection board 5 are aligned with the input terminal portion 3a provided in the head board on the base board 1 for external connection when the positions in the planar direction match. The openings are made so that the connecting terminal portions 6a on the board 5 side correspond to each other accurately and overlap with each other. Further, when the positioning holes 19 and 20 provided in the external connection board 5 and the protective cover 9 match in the planar direction, the protective cover 9
An opening is provided at a suitable position above the connection terminal portion 6a of the external connection board 5 so that the connection terminal portion 6a can be pressed downward. And each of these positioning holes 18,
Preferably, the guide pins 19 and 20 are sized so as to tightly fit with the guide pin 23 as a positioning means which is inserted in communication with the guide pins 23. In this example, each positioning hole 18, 19, 20 is provided at two locations. In the above configuration, the thermal head can be assembled as follows. As shown in FIG. 1, a plate-shaped jig 22 having two guide pins 23 protruding from its upper surface corresponding to the pitch of the two positioning holes 18, 19, 20 provided in each member is prepared, On this jig 22, positioning holes 18, 19,
20 are fitted into the guide pins 23, 23 and overlapped. In this state, the position of the external connection board 5 in the plane direction with respect to the base board 1, that is, more specifically, the input terminal section 3a provided on the head board on the base board and the connection provided on the external connection board 5. The terminal portions 6a are positioned so that they overlap conveniently, and between the external connection board 5 and the protective cover 9, the protective cover covers the upper surface of the connection terminal portion 6a of the external connection board.
It is positioned so that it can apply appropriate pressure to the input terminal portion 3a of the head board. In this way, with the three members 1, 5, and 9 properly and accurately positioned relative to each other in the planar direction, using a plurality of mounting screws 12,
By passing these through the screw holes 1a of the protective cover 9 and the screw holes 5a of the external connection board 5, and then screwing them into the screw holes 11a of the base board 1, the three members described above are connected to each other. Plan. At this time,
When performing the above-mentioned screw tightening work using the first mounting screw, in the final stage of screw tightening, an external force acts to rotate the protective cover 9 clockwise around the axis of the screw. However, two positioning holes are formed in each member, and two positioning pins 2 are inserted into these two positioning holes.
3 and 23 are inserted in communication with each other, even if a force is applied to rotate the protective cover 9 as described above, it is prevented from inadvertently rotating.
The above-mentioned accurate positioning state by the positioning pins 23, 23 is maintained until all the mounting screws 12 have been tightened. After the base board 1, external connection board 5, and protective cover 9 are connected and fixed to each other by the plurality of mounting screws 12 as described above, this assembled body is pulled upward from the jig 22. and insert each positioning pin 23 into the positioning hole 1 of each member.
The product is completed by removing from 8, 19, and 20.
As described above, the thermal head of the present invention can be assembled by a simple operation while ensuring proper positioning in the planar direction between the members constituting the thermal head. Installation errors are also avoided, product accuracy is uniformly stabilized, and automatic assembly is facilitated. Furthermore, in the present invention, since the bar-shaped positioning means is removed after the assembly operation, the thermal expansion coefficient between the base substrate and the protective cover is lower than that in the case where the bar-shaped positioning means remains in the assembled product. It is possible to reduce the occurrence of thermal stress caused by the difference in the temperature.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of this invention, Fig. 2 is an explanatory diagram of the assembly work of the above embodiment, Fig. 3 is an enlarged sectional view of the conventional example, and Fig. 4 is an exploded perspective view of the conventional example. . 1...Base board, 2...Heating resistor, 3...
Driver circuit, 3a... Input terminal section for driver circuit, 5... Board for external connection, 6a... Connection terminal section, 9... Protective cover, 18, 19, 20... Positioning hole, 23... Positioning means.

Claims (1)

[Claims for Utility Model Registration] A base board on which a head board having a driver circuit, its input terminals, and a heat generating resistor is positioned and adhered in a predetermined manner on the front surface, and the above-mentioned input terminal part on one side of the back surface. an external connection substrate having a corresponding connection terminal portion and superimposed on the base substrate so that the connection terminal portion is pressed into contact with the input terminal portion; and an external connection substrate further superposed on the external connection substrate. In a thermal head, the base board, the external connection board, and the protection cover are fixed to each other by a plurality of screws in a superposed state, the base board, the external connection board, and the protection cover The present invention is characterized in that at least two positioning holes are provided in each of the three members, through which the separate insertable and removable rod-shaped positioning means can be inserted in communication with each other in a predetermined fit while defining the relative position in a plane between the three members. , thermal head.