JPH0321963Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a structure of a thermal head suitable for increasing printing speed in thermal recording using a thermal head.

<Prior Art> FIG. 4 is a plan view of a printing portion of a conventional thermal head, and FIG. 5 is a block diagram of a driving section of this thermal head. In the figure, 1 is the printing part of the thermal head, among which R1, R2, R3...Rn
One end is connected to the common electrode C, and the other end is connected to the electrode P.
1, P2, P3... are heating elements connected to Pn.

2 is a control section, which includes electrodes P1, P2, P3.
...Switches S1, S2, S3... connected to Pn
Sn is controlled, and the driving power supply Vb is connected to the heating element R from the power supply 3.
1, R2, R3...Rn.

With this configuration, move the thermal head 1 along the arrow A.
By selectively heating the heating elements R1, R2, R3...Rn while moving the heating elements R1, R2, R3, . ,R3...Rn
A dot of the size is printed.

In this case, the time t during which the thermal head 1 is in contact with the thermal paper or the ink ribbon is
When L is the dot length determined by the lengths of 1, R2, R3...Rn, and v is the moving speed of the thermal head 1, it is expressed as t=L/v (1). In order to increase the printing speed, it is necessary to increase the moving speed v of the thermal head 1, but the contact time t becomes shorter accordingly.

The thermal head 1 has a thermal time constant, and the heating element R
It takes time for the 1, R2, R3, . Furthermore, applying a large drive voltage to the head in a short period of time has the disadvantage of shortening the life of the head, and hitherto the structure of thermal heads has had various limitations in increasing the printing speed.

<Problems to be solved by the invention> The technical problem to be solved by the invention is to realize a thermal head with a structure suitable for increasing printing speed.

<Means for Solving the Problems> The configuration of the present invention is such that vertical strip heating elements and horizontal strip heating elements are arranged in multiple layers in a matrix, and a driving power supply is applied to the vertical heating elements and the horizontal heating elements. is selectively applied to generate a temperature higher than the coloring temperature of the thermosensitive recording at the intersection of these heating elements.

<Operation> The above technical means operates as follows. That is,
It is possible to selectively heat any intersection point between the heating elements in the vertical row and the heating elements in the horizontal row. For this reason, for example, if a plurality of intersection points arranged on a line in the same direction as the thermal head are synchronously controlled so as to generate heat on the same printing area in relation to the movement speed of the thermal head. , the same printing area can be heated by dividing it into multiple intersection points,
Even if the moving speed of the thermal head increases, the total contact time with the thermal paper or the like remains the same as in the original case, and printing of the same quality can be achieved.

<Examples> Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a printing section of a thermal head of an apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram of a driving section of this thermal head. In these figures, elements that are substantially the same as those in FIGS. 4 and 5 are given the same reference numerals, and explanations thereof will be omitted. Rx1, Rx2, Rx3...Rxn has one end connected to the common electrode Cx, and the other end connected to the electrode Px
1, Px2, Px3...The dotted line parts Ry1 and Ry2 are strip-shaped heating elements in a vertical row connected to the common electrode Cy and the other end to the electrodes Py1 and Py2. These heating elements are arranged in multiple layers in a matrix (in Figure 2, heating elements Rx1, Rx2, Rx3...Rxn, heating elements Ry1,
Although Ry2 is shown crossing, these heating elements are not in electrical contact. ).

The switches Sx1, Sx2, Sx3...Sxn connected to the electrodes Px1, Px2, Px3...Pxn are controlled by the control unit 2, and the power supply Vx for row drive is applied from the power supply 3 to the heating elements Rx1, Rx2, Rx3...Rxn. do.

Similarly, the switches Sy1 and Sy2 connected to the electrodes Py1 and Py2 are controlled by the control unit 2, and the power supply Vy for column drive is connected to the heating element from the power supply 3.
Apply to Ry1 and Ry2.

The operation of the apparatus according to the embodiment of the present invention constructed as described above will be explained with reference to the waveform diagram shown in FIG. Row heating elements Rx1, Rx2, Rx3...Rxn and vertical heating elements Ry
1, the intersection with Ry2 is A1, A2, A3...An, B
1, B2, B3...Bn, and here, the intersections A1, Bn, which are on the same line as the moving direction of the thermal head 1,
The explanation will focus on B1.

Figure 3a shows the application state of the drive power Vx to the row heating element Px1, Figure 3b shows the application state of the drive power Vy to the column heating element Ry1, and Figure 3c shows the application state of the drive power Vy to the column heating element Ry1.
FIG. 3 d shows the state of application of the driving power Vy to Ry2, the temperature state at the intersection A1, and FIG. 3 e the temperature state at the intersection B1.

Between time t0 and t1, the row heating element Rx1
A driving power is applied to the column heating element Ry1, and the intersection A1 generates heat to a coloring temperature level L1 or higher. Also, between time t1 and t2, the row heating element Rx
A driving power is applied to the heating elements Ry2 and 1, and the intersection point B1 generates heat to a temperature higher than the coloring temperature L1.

The timing of application of these driving power sources is adjusted in consideration of the moving speed of the thermal head 1, and the intersection point A is adjusted.
If synchronous control is performed so that 1 and B1 generate heat on the same printing area, the same printing area can be connected to the intersection point A of the two
1 and B1 can be heated, and even though the temperature at the intersection of 1 and 1 is relatively low, just below the coloring temperature, a sufficient amount of heat necessary for coloring can be obtained in total.

That is, when the moving speed of the thermal head 1 doubles, the time during which each of the intersection points contacts the thermal paper etc. becomes 1/2 shorter, but the total contact time remains the same as in the original case. Printing with the same quality is possible.
In this embodiment, there were two vertical rows of heating elements, but if these heating elements are arranged in n rows and adjusted so that these heating elements generate heat at the same printing location, the printing speed can be increased by n times. However, it can print with the same quality as gold.

Further, while the driving power source is connected to the heating elements in the horizontal rows or the heating elements in the vertical rows for preheating, the driving power source is selectively applied to the heating elements in the vertical rows or the heating elements in the horizontal rows based on the signal from the control unit 2. By doing this, the temperature of the selected intersection point can be changed to the coloring temperature L in a short time.
It can be increased to more than 1.

<Effects of the Invention> According to the present invention, arbitrary points of intersection between the heating elements in the vertical row and the heating elements in the horizontal row can be selectively heated. As a result, the plurality of intersection points are synchronously controlled in relation to the moving speed of the thermal head so that heat is generated on the same printing area, and the same printing area is shared and heated by the plurality of intersection points. If this is done, even if the moving speed of the thermal head increases, the total time during which the heating element comes into contact with the thermal paper or the like remains the same as in the original case, and printing of the same quality can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the printing part of the thermal head of the apparatus according to the embodiment of the present invention, Fig. 2 is a block diagram of the driving section of the thermal head shown in Fig. 1, and Fig. 3 is an explanation of the operation of the apparatus according to the embodiment of the present invention. 4 is a plan view of a printing portion of a conventional thermal head, and FIG. 5 is a block diagram of a driving section of the thermal head shown in FIG. 4. 1...Thermal head, Rx1, Rx2, Rx3
...Rxn...Horizontal rows of band-shaped heating elements, Ry1, Ry2...
... Vertical strip heating elements, 2... Control section, 3
……power supply.

Claims (1)

[Scope of utility model registration request] arranging strip-shaped heating elements in vertical columns and strip-shaped heating elements in horizontal columns in a multilayered matrix, selectively applying a driving power to the heating elements in the vertical columns and the heating elements in the horizontal columns;
A thermal head characterized in that a temperature higher than the coloring temperature of a thermosensitive recording material is generated at the intersection of these heating elements.