JP2503898Y2 - Thermal head - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermal head used in a facsimile or the like, and more specifically, to a wiring structure of a common power activating conductor of a plurality of driving integrated circuits for driving heating elements. Regarding

Prior Art A typical prior art is shown in FIG. A plurality of resistance heating elements 2 are arranged on the ceramic substrate 1 at intervals to form a heating element row 3. As shown in FIG. 11, a conductor 4 for wiring is formed on the ceramic substrate 1 by vapor deposition or the like. The conductor 4 for this wiring is
It is composed of an individual conductor 5 and a control conductor 6. A driving integrated circuit 8 is fixed on the power supply conductor 7, and the integrated circuit 8
Is supplied with electric power from the electric conductor 7 for supplying electric power, and this electric power is selectively led to the individual conductor 5 by a control signal from the electric conductor 6 for control, and is applied to one terminal of each resistance heating element 2. To be

The other terminal of the resistance heating element 2 is commonly connected to the conductor 9. The conductors 6, 7, 9 have flexible wiring boards 10 on them.
A DC power source is supplied between the conductor 7 for supplying power and the conductor 9 via the control conductor 6, a control signal is supplied to the control conductor 6, and each integrated circuit 8 controls a plurality of resistance heating elements 2.
The conductors 6, 7, 9 and the conductor 11 formed on the wiring board 10 are
The ceramic substrate 1 and the flexible wiring substrate 10 are pressed against each other for individual connection, thereby achieving electrical conduction.

Problems to be Solved by the Invention It is difficult for the ceramic substrate 1 to form a flat surface on which the conductors 4, 7, 9 are formed, and the surface is generally curved. Therefore, even if the flexible wiring board 10 is pressed against the conductors 6 and 7 and the like, a gap is formed therebetween, and for example, the electric conductor 7 for power supply and the conductor 11 formed on the wiring board 10 are electrically connected. Contact is uncertain. When the electrical contact of the power supply conductor 7 is poor, the power is not supplied to the large number of resistance heating elements 2 controlled by the integrated circuit 8 connected to the conductor 7, which makes printing uncertain. Will be things.

An object of the present invention is to provide a thermal head capable of reliably energizing a heating element array with electric power, improving the quality of thermal printing, and reducing power consumption.

Means for Solving the Problems The present invention provides a heating element array in which a plurality of resistance heating elements are linearly arranged, and a resistance heating element that is arranged along the heating element array and outputs power through a power supply terminal. A plurality of driving integrated circuits for selectively supplying heat to the elements to drive heat generation, a conductor commonly connected to the power supply terminals provided in each of the product circuits, and extending the conductors. A thermal head comprising a plurality of connection terminals and a control connection terminal for introducing a control signal to the driving integrated circuit, which are provided on an electrically insulating substrate.

The present invention also provides a flexible wiring board having a control wiring conductor and a power supply wiring conductor,
It is characterized in that the power supply wiring conductor is pressure-connected to the control connection terminal and the connection terminal provided on the electrically insulating substrate.

According to the present invention, the conductor formed on the electrically insulating substrate is provided in each of the plurality of driving integrated circuits or the seventh integrated circuit described later.
As shown in the figure, they are commonly connected to the power supply terminals provided in each of the two or more grouped driving integrated circuits. As a result, even if the electrically insulating substrate is made of ceramic or the like and is curved, and a flexible wiring substrate or the like for supplying power to the power supply terminal and one of the connection terminals are separated from each other. Electric power is supplied to the driving integrated circuit corresponding to the separated connection terminals via the other connection terminals, and it becomes possible to drive the resistance heating element corresponding thereto. Therefore, the heating element array can be positively energized, and the quality of thermal printing can be improved.

Further, the conductor on the electrically insulating substrate, as described above,
Since each of the plurality of driving integrated circuits or each of the grouped two or more driving integrated circuits is commonly connected to a power supply terminal, for example, the flexible wiring is provided. The electric power supplied through the substrate or the like is selected and supplied from the plurality of power supply terminals having the smallest electric resistance, so that the power consumption can be reduced.

Embodiment FIG. 1 is an exploded perspective view showing the construction of an embodiment of the present invention. A heating element row 23 is formed by arranging a plurality of resistance heating elements 22 on a ceramic substrate 21 at intervals. The resistance heating elements 22 are grouped into a plurality of groups, and the resistance heating elements 22 in each group are integrated driving circuit elements.
Electrically connected to 24.

FIG. 2 is a plan view of the ceramic substrate 21 with the driving integrated circuit element 24 removed. Ceramic substrate
A conductor 25 for supplying electric power is arranged on 21. The conductor 25 is a common conductor portion extending in the longitudinal direction of the heating element row 23.
26, and a plurality of branch conductor portions 27 extending from the common conductor portion to the side opposite to the heating element row 23 at intervals in the longitudinal direction.
It consists of and. On the common conductor portion 26, the integrated circuit elements 24 are arranged at intervals. A control conductor 28 for receiving a control signal for driving and controlling the integrated circuit element 24 is provided between the branch conductor portions 27, and the ceramic substrate 21.
Formed on. Further, an individual conductor 29 corresponding to each resistance heating element 22 is formed on the ceramic substrate 21 between the supply conductor portion 26 and the heating element array 23.

The integrated circuit element 24 is of a so-called flip chip type, has a width wider than that of the common conductor portion 26, and has a plurality of back surfaces 30 on the heating element row 23 side of the common conductor portion 26. The heating element array has an individual connection terminal 31 individually corresponding to the resistance heating element 22, and the heating element array is more than the common conductor portion 26.
A control signal terminal 32 for receiving a control signal for individually controlling the driving of the resistance heating elements 22 is provided on the side opposite to 23. Further, on the back surface 30, a power supply terminal 36 for supplying power from the common conductor portion 26 to the integrated circuit element 24 is formed.

Such an integrated circuit element 24 is disposed over the common conductor portion 26, and the terminal 3 formed on the back surface 30 thereof.
As shown in FIG. 3, 1, 32 are the individual conductors 29, respectively.
And is connected to the control conductor 28 via the solder 33. The power supply terminal 36 is connected to the common conductor portion 26 via solder 33. On the ceramic substrate 21, each resistance heating element 22
A common conductor 34 for commonly supplying electric power is formed.

The conductors 25, 28, 29, 34 are made of, for example, aluminum, the surface of which is plated with nickel or the like, and the portions connected to the respective connection terminals are plated with gold over nickel plating. . A wiring board 35 is provided on the free end side of the branch conductor portion 27 and the control conductor 28.
Is arranged. The wiring board 35 includes, for example, a board 45 made of a flexible synthetic resin material having electrical insulation, and the conductors 25, 28, 29, 34 on the surface 46 of the board 45 facing the ceramic board 21. It is composed of a plurality of wiring conductors 48 formed so as to correspond to each other.

The wiring conductor 48 includes a connection terminal 51 and a conductor portion 52 which are individually connected to the conductors 25, 28, 29, 34. External terminals 54 to which the connection terminals 51 of the wiring board 35 are connected are formed at the free ends of the branch conductor portion 27 and the control conductor 28.

FIG. 4 is a diagram showing the principle of the thermal head 60.
A predetermined power is supplied between the power supply conductor 25 and the common conductor 34. The resistance heating element 22 connected between the common conductor 34 and the common conductor portion 26 via the plurality of switching elements SW in the integrated circuit element 24 selectively operates according to the switching mode of the switching element SW. Driven.

FIG. 5 shows a thermal head 60 which is an embodiment of the present invention.
It is a longitudinal cross-sectional view showing the configuration of. The thermal head 60 includes a ceramic substrate 21 on which the heating element array 23 and the integrated circuit element 24 are arranged, a wiring substrate 35, a reinforcing plate 61 for reinforcing the wiring substrate 35, a reinforcing plate 61 and the ceramic substrate 21. And a head cover 63 that covers them. Connection terminals 51 formed on the ceramic substrate 21 and external terminals 54 formed on the wiring substrate 35.
Are pressed and electrically connected by a pressing member 65 made of, for example, rubber provided in the groove 64 formed in the head cover 63. This head cover 63
Are fixed to the reinforcing plate 61 by screw members 66.

FIG. 6 is a diagram showing a simplified basic configuration of the thermal head 60. In FIG. 6, the path of the control signal is omitted. To the connector 53 provided on the wiring board 35, a connector 71 to which a control signal from the power / control signal circuit 70 and power for printing is supplied is connected. The connector 53 includes power supply lines 1 and 1 individually corresponding to the integrated circuit elements 24 arranged on the ceramic substrate 21.
2, ..., li, ..., ln are formed, and the power for printing is supplied through the power supply line li to the power supply conductor.
It is supplied to the branch conductor portion 27 of 25.

Since the branch conductor portions 27 are connected to each other by the common conductor portion 26, the electric current supplied from the connector 53 flows through the power source line li having the smallest electric resistance among the plurality of power source lines li. Therefore,
Large current does not flow in the power supply line with large resistance,
It is possible to prevent heat generation regardless of printing.

Similarly, since the power supply conductors 25 are commonly connected in the common conductor portion 26 as described above, the current paths of the electric power supplied to the respective integrated circuit elements 24 have a plurality of current paths. Drive current flows. Therefore, the value of the current flowing through each power supply line li can be reduced, which also reduces the amount of heat generation unrelated to printing, thus reducing power consumption.

In the ceramic substrate 21, it is difficult to form a flat surface on which the conductors 25, 28, 29, etc. are formed as described in the section of the prior art, and the surface is curved. There are many. Therefore, even if the wiring board 35 made of the flexible material is pressed toward the ceramic board 21 by the pressing member 65, the contact state between the connection terminal 51 of the wiring board 35 and the external terminal 54 of the ceramic board 21 is not good. Certainly, a partial contact failure may occur. However, in the power supply conductor 25 of the present invention, the branch conductor portion 27 corresponding to each integrated circuit element 24 is commonly connected by the common conductor portion 26, so that the partial contact failure as described above occurs. However, it is possible to supply a driving current to the integrated circuit element 24 corresponding to this portion from another current path, and it is possible to prevent deterioration of print quality due to poor contact.

FIG. 7 is a schematic diagram showing the configuration of another embodiment of the present invention. In the power supply conductor 25 of the first embodiment, although all the branch conductor portions 27 corresponding to the integrated circuit element 24 are connected by the common conductor portion 26,
In the power supply conductor 25a of this embodiment, the common conductor portion 26a is provided only for the plurality of grouped branch conductor portions 27.

FIG. 8 is a simplified diagram showing the configuration of still another embodiment of the present invention. In the power supply conductor 25b of the present embodiment, the notch 80 is formed in the common conductor portion 26b, which is convenient for the arrangement of the integrated circuit element 24 and the connection of the conductors 28, 29 and the like.

FIG. 9 is a schematic view showing the configuration of still another embodiment of the present invention. In the power supply conductor 25c of this embodiment, the branch conductor portions 27 are formed for every other integrated circuit element 24. As a result, the number of control conductors 28 can be increased and the widths of the control conductors 28 and the branch conductor portions 27 can be increased. 7 to 9, the other conductors 28 and 29 and the structure related thereto are omitted.

In this embodiment, the flip-chip type is used as the integrated circuit element 24, but an integrated circuit element in which terminals and conductors are connected by so-called wire bonding may be used. Further, the terminals protruding outside from the coating layer of the integrated circuit element may be electrically connected to each conductor by soldering.

As described above, according to the present invention, the electrically insulating substrate is curved and the connection terminals provided on the electrically insulating substrate are separated from the power supply wiring conductor of the flexible wiring board, for example. However, since the driving current is supplied from another current path to the driving integrated circuit corresponding to the separated portion, it is possible to prevent the deterioration of the printing quality due to the contact failure. In addition, since a driving current flows through each driving integrated circuit through a plurality of current paths, the value of the current flowing through each conductor can be reduced, and the heat generation amount of each conductor can be minimized. be able to. Further, since there are a plurality of current paths, a large current flows through the current path with the smallest resistance value. Therefore, the current does not flow through the current path with the largest resistance value. Can be reduced, and the power consumption can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing the structure of an embodiment of the present invention, FIG. 2 is a plan view showing a state where an integrated circuit element 24 is removed from a ceramic substrate 21, and FIG. FIG. 4 is a cross-sectional view showing the connection structure, FIG. 4 is a view showing the basic principle of the present invention, and FIG. 5 is a vertical cross-sectional view showing the structure of the thermal head 60.
FIG. 6 is a diagram showing a simplified basic structure of the thermal head 60, FIG. 7 is a diagram showing a simplified structure of a second embodiment of the present invention, and FIG. 8 is a third embodiment of the present invention. FIG. 9 is a simplified view of the configuration of FIG. 9, FIG. 9 is a simplified view of the configuration of the fourth embodiment of the present invention, FIG. 10 is a plan view showing the configuration of a typical prior art, and FIG. FIG. 11 is a plan view of the substrate 1 used in the prior art shown in FIG. 10. 21 ... Ceramic substrate, 22 ... Resistance heating element, 23 ... Heating element array, 24 ... Integrated circuit element, 25, 25a, 25b, 25c ... Power supply conductor, 26 ... Common conductor part, 27 ... Branch conductor part, 28 ... Control conductor, 29 ... Individual conductor, 31 ... Individual connection terminal, 32 ... Control signal terminal, 34 ... Common conductor, 35 ... Wiring board, 48 ... Wiring conductor,
51 ... Connection terminal, 52 ... Conductor part, 53, 71 ... Connector, 54
… External terminal, 60… Thermal head, power supply / control signal circuit

Claims (2)

(57) [Scope of utility model registration request] 1. A heating element array in which a plurality of resistance heating elements are linearly arranged, and electric power is selectively supplied to the resistance heating elements via a power supply terminal arranged along the heating element array. A plurality of driving integrated circuits that are driven to generate heat, and commonly to each of these driving integrated circuits or the power supply terminals provided in each of two or more driving integrated circuits grouped together. A thermal head in which a conductor to be connected, a plurality of connecting terminals formed by extending the conductor, and a control connecting terminal for introducing a control signal to the driving integrated circuit are provided on an electrically insulating substrate. . 2. A flexible wiring board having a control wiring conductor and a power supply wiring conductor, a control connection terminal in which the control wiring conductor and the power supply wiring conductor are provided on an electrically insulating substrate, and a connection. The thermal head according to claim 1, wherein the thermal heads are connected to the terminals under pressure.