JP2505798Y2 - Wiring structure of the edge type print head substrate - Google Patents

Description

[Detailed description of the device]

[Industrial applications]

The present invention relates to a wiring structure for an end-face type print head substrate.

[Prior art]

For example, in a line type thermal print head, heating dots made of a heating element are continuously formed in a row on a ceramic substrate, and the above-mentioned heating dot example is formed through a comb-shaped electrode pattern which is continuous with the heating dots. It is configured to heat the selected portion. Normally, a thermal print head is constructed by arranging heating dots in a line along the edge of the surface of the print head substrate, but one block of heating dots consisting of a predetermined number of heating dots is driven by one driver IC. In addition, each common electrode lead of the heating dot is commonly connected to a common wiring pattern provided on the print head substrate along the heating dot. Since the heating dots are arranged in the longitudinal direction of the print head substrate without gaps, the common wiring pattern is formed in the longitudinal direction so as to be parallel to the heating dot row. Is pulled out to the side where the driver IC is provided and is connected to a flexible circuit board or the like extended from the main body of the printer. However, as the print width increases, the overall length of this common wiring pattern becomes longer, and the voltage applied to the heating dots drops significantly at the center of the print head in the width direction. The problem of adversely affecting In order to solve the above problem, in a normal line type thermal print head, the common wiring pattern is formed thick or the common wiring pattern of the common wiring pattern is formed from the back surface of the heat dissipation plate fixing the print head substrate. A method of increasing the current capacity and reducing the resistance by connecting a flexible printed cable or the like having an auxiliary pattern formed in the middle portion is adopted. By the way, in the conventional line type thermal print head described above, a drive circuit is often mounted on the same main plane where the heating dots are formed on the head substrate. However, it was necessary to carry out troublesome handling such as pressing it against the platen or backup member. For this reason, the size of the device using the thermal print head is increased, and it is necessary to apply a constant pressing force to the recording paper supported by the backup member over the entire length of the linearly extending heating dot row. However, the bending rigidity of a certain level or more is required, and therefore, the thermal print head cannot be made thinner. In order to solve the above problem, an end face type thermal print head in which heat generating dots are arranged on the end face portion of the head substrate has been developed and put to practical use widely. Also in the above-mentioned end face type thermal print head, when the printing width becomes long, the voltage applied to the heat generating dot is reduced in the vicinity of the central portion of the print head as in the conventional case. Therefore, on the back surface along the end surface portion, while providing a common reinforcing wiring pattern for conducting the common electrode derived from the heating dot, on both sides of the surface, one end conducts to the common reinforcing wiring pattern, A method of forming a common reinforcing electrode whose other end is connected to the flexible circuit board or the like and increasing the thickness of the common reinforcing wiring pattern and the common reinforcing electrode to increase the current capacity and reduce the resistance is taken. There is.

[Problems to be solved by the device]

In the end face type thermal print head, the common reinforcing wiring pattern and the common reinforcing electrode for reinforcing the common electrode to increase the current capacity are formed in a state of being divided into the front and back surfaces of the head substrate. There is. Therefore, it is necessary to form the common reinforcing wiring pattern on both sides of the heating dot on the end face portion and the conducting portion for conducting the common reinforcing electrode. However, since the conducting portion must be formed so as to pass through both sides of the heating dot row at the top of the end face portion, like the common reinforcing wiring pattern or the common reinforcing electrode,
If the thickness is increased to reinforce, the thickness of the heating dot array becomes thicker than that of the heating dot array, which deteriorates the paper contact with the heating dot array and deteriorates the print quality. Further, if the current capacity is increased by increasing the width of the conducting portion, the length of the head substrate becomes long, which is against the demand for miniaturization. Therefore, there is a problem that it cannot be applied to a print head having a long print width. The invention of the present application was conceived under the above-mentioned circumstances, solves the above-mentioned conventional problems, and forms a common reinforcing wiring pattern formed on the back surface and a common reinforcing wiring pattern formed on the front surface in an end-face type print head substrate. It is an object of the present invention to provide a wiring structure of an end face type print head substrate which can easily reinforce the conduction with the common reinforcing electrode.

[Means for Solving the Problems]

In order to solve the above problem, the present invention takes the following technical means. That is, according to the invention of the present application, the heating dots are arranged in rows on the front and back surfaces of the strip-shaped head substrate in a rounded continuous end face portion, while the common electrode derived from the heating dots is provided on the back face along the end face portion. In an end face type print head substrate, which is provided with a common reinforcing wiring pattern for conducting, and has common reinforcing electrodes conducting at both ends of the common reinforcing wiring pattern on both sides of the front surface, both sides of the front surface and the back surface of the head substrate. Reinforcement wiring structures are provided on both side end faces that are continuous with the edge so that the respective end portions of the common reinforcement wiring pattern and the common reinforcement electrodes are electrically connected to each other.

[Function and effect of device]

According to the invention of the present application, in an end-face type print head substrate, a common reinforcing electrode provided on both sides of the front surface and both ends of a common reinforcing wiring pattern provided on the back face are provided on both end faces of the print head substrate by a reinforcing wiring structure. By making the conductive state, the current capacity of the common electrode is increased and its resistance value is reduced. Both end surfaces on which the reinforcing wiring structure is formed are portions that are continuous with the side edges of the front surface and the back surface of the head substrate and that extend orthogonally from both ends of the end surface portion where the heating dots are arranged. Therefore, even if a reinforcing wiring structure having a large thickness is provided on the side end surface, the contact of the heating dot row with the printing paper does not change. Further, since the side end surface is continuous with the entire length of the side edges of the front surface and the back surface of the head substrate, it is possible to provide a wiring structure having a large width and form a reinforcing wiring structure having a desired capacitance. be able to. Further, by omitting the conducting portions provided at both ends of the end face portion on which the heating dot row is formed, the heating dot row can be formed to the full width of the head substrate, and the head substrate can be downsized. It will be possible. Further, even if a plurality of head substrates are provided in series, the breaks in the heating dot examples are almost eliminated, so that it is possible to deal with a print head having a long printing width. As described above, the reinforced wiring structure according to the present invention makes it possible to significantly reduce the resistance of the common electrode, can be applied to a print head having a long print width, and can improve print quality by eliminating uneven print density. Can be improved.

[Explanation of the embodiment]

An embodiment of the present invention will be specifically described below with reference to FIGS. 1 to 3. FIG. 1 is an external perspective view of an edge type print head substrate according to the present invention. As shown in this figure, an end face type print head substrate 1 has a strip-shaped head substrate 2 formed of ceramic or the like having a certain thickness, and at one end thereof, a front surface 3 and a back surface 4 are continuous end surfaces with roundness. The portion 5 is formed, and the heating dots 6 are arranged in a row on the top of the end surface portion 5 to be generally configured. A driver circuit 7 is mounted on the surface 3 of the head substrate 2 in the same manner as a conventional thermal print head substrate to form a drive circuit 8, and comb-shaped drive electrode leads 9 extending from the drive circuit 8 are formed. The heating dots 6 are electrically connected. Also, the common reinforcing electrode 10
And the lead patterns 11 for external connection are drawn out from the drive circuit 8 and are arranged in a comb shape in the central portion of the surface 3. On the other hand, on the back surface 4 of the head substrate 2, a common reinforcing wiring pattern 12 is formed in parallel with the end surface portion 5, and the common electrode lead 13 led out from each heating dot 6 is the common reinforcing wiring. Commonly connected to pattern 12. The common reinforcing wiring pattern 12 formed on the back surface 4 of the head substrate 2 and the common reinforcing electrode 10 formed on the front surface 3 of the head substrate 2 are provided on both sides of the heating dot row 6a formed on the end face portion 5. They are connected by a conducting portion 14 formed through the. Then, the surface 3 of the head substrate 2
In, a flexible cable (not shown) having a terminal portion corresponding to the external connection lead pattern 11 and the common reinforcing electrode 10, is connected and fixed so as to be superimposed on the connection lead pattern 11 and the common reinforcing electrode 10, Electric power and a drive signal are supplied to the drive circuit 8 and the heating dots 6 to drive the thermal print head. The common reinforcing wiring pattern 12 and the common reinforcing electrode 10 in the present embodiment are reinforced by being formed thicker than other lead patterns to increase the current capacity and decrease the resistance value. Has been. Now, as shown in FIG. 1, in this embodiment, at both end surfaces 15a and 15b which are continuous with both side edges of the front surface 3 and the back surface 4 of the head substrate 2, the end portions of the common reinforcing wiring pattern 12 are A reinforcing wiring structure 16 is formed to electrically connect between the common reinforcing electrodes 10. FIG. 2 is a sectional view taken along the line II-II in FIG. As shown in this figure, in the reinforcing wiring structure 16, a conductor film that wraps around the edges of the front surface 3 and the back surface 4 of the head substrate 2 is formed as a thick film on both end surfaces 15a and 15b of the head substrate 2. It is provided by Next, a method of forming the reinforcing wiring structure 16 will be described. In the present embodiment, as shown in FIG. 2, the reinforcing wiring structure 16 is formed by using a jig 18 having a substantially U-shape having an inner wall surface 17 corresponding to the side sectional shape of the head substrate 2. . First, a conductor paste 19 such as silver paste is applied to the inner wall surface 17 of the jig 18 to a predetermined thickness. Next, the jig
The inner wall surface 17 coated with the conductor paste 19 of 18 is pressed against both end surfaces 15a and 15b of the head substrate 2 so as to sandwich the side portions of the head substrate 2, and the conductor paste 19 is attached to the side surface 15a of the head substrate 2. , 15b or front 3 and back 4
Transfer to the top. The conductor pace and 19 are the head substrate 2
From both end surfaces 15a, 15b to both ends of the common reinforcing electrode 10 on the front surface 3 and the common reinforcing wiring pattern 12 on the rear surface 4, and then transferred by firing the head substrate 2 at a predetermined temperature. The conductive paste 19 is solidified and fixed to form the reinforcing wiring structure 16. The side end surfaces 15a, 15b on which the reinforcing wiring structure 16 is formed are
It is a portion that is continuous with the side edges of the front surface 3 and the back surface 4 of the head substrate 2 and that extends orthogonally from both ends of the end surface portion 5 on which the heating dot rows 6a are formed. Therefore, even if the thick film reinforcing wiring structure 16 is provided on the side end surfaces 15a and 15b, the contact of the heating dot row 6a with the printing paper does not change and the printing quality does not deteriorate. Further, since the respective side end surfaces 15a and 15b are continuous with the entire length of the side edges of the front surface 3 and the back surface 4 of the head substrate 2, it is possible to provide the reinforcing wiring structure 16 having a large width, which is desirable. The reinforcing wiring structure 16 having a capacitance can be formed. Further, if the conducting portions 14 provided at both ends of the end face portion 5 on which the heating dot row 6 is formed are omitted, the heating dot row is formed.
6a can be formed to the full width of the head substrate 2, and the head substrate 2 can be downsized. Further, even if a plurality of head substrates are provided in series, the breaks in the heating dot example 6a are almost eliminated, so that it is possible to cope with a print head having a long printing width. FIG. 3 is a view corresponding to FIG. 2 of another embodiment of the present invention. In this embodiment, instead of directly forming a wiring pattern on both end surfaces 15a and 15b to form a reinforcing wiring structure, a clip-shaped reinforcing wiring device 16a having a substantially U-shaped cross section is formed.
Is used to form the reinforcing wiring structure 16 according to the present invention. As shown in FIG. 3, the reinforcing wiring device 16a is a resin-molded product having an inner wall surface 20 corresponding to the cross-sectional shape of the side portion of the head substrate 2 and having a substantially U-shaped cross section. A conductor film 21 of copper or the like is attached and formed. The space between the inner walls 20a, 20a of the U-shaped end portions of the reinforcing wiring device 16a is formed to be slightly smaller than the thickness of the side portion of the head substrate 2. The head substrate 2 is fixed on both side end surfaces 15a and 15b so as to be elastically sandwiched from the side portions of the head substrate 2. Inner wall surface of the above reinforcing wiring device 16a
The common reinforcing electrode 10 and the common reinforcing wiring pattern 12 are separated from each other by elastically pressing the ends of the conductor film 21 formed on 20 to both ends of the common reinforcing electrode 10 and the common reinforcing wiring pattern 12. It is conducted. According to this embodiment, the reinforcing wiring structure 16 can be formed only by elastically fitting the reinforcing wiring device 16a on both sides of the head substrate 2, and the subsequent steps such as firing become unnecessary, thus reducing the manufacturing steps. Thus, the manufacturing cost can be reduced. As described above, the reinforced wiring structure according to the present invention makes it possible to significantly reduce the resistance of the common electrode, eliminate uneven printing density, and significantly improve printing quality. The scope of the present invention is not limited to the above embodiments. In the embodiment, the reinforcing wiring structure 16 is formed using the jig 18 having a substantially U-shaped cross section, but the reinforcing wiring structure may be formed by other means such as coating. Further, although the reinforcing wiring device 16a is made of resin in the second embodiment, it may be made of metal having conductivity and elasticity.

[Brief description of drawings]

FIG. 1 is an external perspective view of a wiring structure of an end face type print head substrate according to the present invention, FIG. 2 is a sectional view taken along the line II-II in FIG. 1, and FIG. 3 is another embodiment of FIG. It is a figure equivalent to. 1 ... Edge type print head substrate, 2 ... Head substrate,
3 ... front surface, 4 ... back surface, 5 ... end surface portion, 6 ... heating dot, 10 ... common reinforcing electrode, 12 ... common reinforcing wiring pattern, 15 ... side end surface, 16 ... reinforcing wiring structure.

Claims (1)

(57) [Scope of utility model registration request] 1. A strip-shaped head substrate has rounded and continuous rounded end face portions on which heat-generating dots are arranged in rows, and on the back face along the end-face portion, a common electrode derived from the heat-generating dots is electrically connected. In the end face type print head substrate, which is provided with a common reinforcing wiring pattern and which has a common reinforcing electrode that is electrically connected to both ends of the common reinforcing wiring pattern on both sides of the front surface, both side edges of the front surface and the back surface of the head substrate. Wiring structure of an end face type print head substrate, characterized in that a reinforcing wiring structure is provided on each of both side end surfaces continuous with each other to electrically connect each end of the common reinforcing wiring pattern and each of the common reinforcing electrodes. .