JPH01115652A - Thermal printer device - Google Patents

Abstract

PURPOSE:To obtain a thermal printer device eliminating the fluctuation of printing density, by synchronously electrically conducting heating resistors disposed dispersedly every predetermined number of pieces every time when each of a plurality of control signals is applied. CONSTITUTION:Printing data sent from a host side is inputted to a shift register 3 in synchronism with a clock and temporarily accumulated therein. The printing data is outputted to a latch circuit 4 while shifting also in synchronism with a clock and latched therein. An output signal from the latch circuit 4 is electrically conducted to heating resistors which are connected to an output of a NAND circuit 5 connected to each strobe signal every time when a strobe pulse per block is applied, and a printing is performed. The heating resistors to be synchronously electrically conducted are disposed dispersedly every n- pieces, whereby a change in printing density is improved to a great extent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a thermal printer device, and particularly to a thermal printer device with constant printing density.

[Prior Art] FIG. 2 is a diagram showing the configuration of a conventional thermal printer device. In the figure, (3) is a shift register that temporarily stores print data, and (4) is a shift register (3).
The latch circuit is connected to the latch circuit, (r,,) to (r,,) are the heat generating resistors of the first block, (r21) to (r2.) are the heat generating resistors of the second block, (r3.) to ( r,) is the heating resistor of the third block, ...(rn,) ~ (r
□) is the heating resistor of the n-th block. (STI),
(Sr1), (Sr1), . . . (STn) are strobe signal lines for each block.

(5) is a NAND circuit provided in the number of heating resistors, one of which is connected to each output of the latch circuit (4), and the other connected to each strobe signal line.

FIG. 3 shows the strobe signal line (ST1) in FIG. 1.

It is a diagram showing pulse waveforms applied to (Sr1), (Sr1), . . . (STn).

FIG. 4 is a diagram for explaining the causes of print density fluctuations in a conventional thermal printer device. In the figure, (1) is a power source, which includes a battery (E) and an internal resistance (Rs). (2) is the power supply (1) through the wiring resistance (R1)
This is a thermal head connected to the

FIG. 5 is a diagram showing unevenness in print density when printing with a conventional thermal printer device.

A conventional thermal printer device is configured as described above.
Print data sent from the host side (not shown) is input to the shift register (3) in synchronization with the clock, and -
Accumulated over time. This print data is also output to the latch circuit (4) while being shifted in synchronization with the clock.
Latched. Next, the output signal from the latch circuit (4) is applied to the heating resistor of each block, which is connected to the output of the NAND circuit (5>), which is connected to each strobe signal line each time the strobe pulse for each block is sequentially applied. body (rl, ~r
+m)+(+”2r~r2j+(raI~r:++a)
H+...' (rn+ to roW,) are sequentially energized to print.

[Problem that the invention attempts to solve] In traditional thermal printer equipment like the one mentioned above.

Internal resistance (R5) of power supply (1) as shown in Figure 4
, the wiring resistance (11) and the wiring pattern resistance (not shown) in the thermal head (2), etc., as shown in FIG. In addition, in conventional energization, the influence of heat from adjacent dots is caused by two heating resistors (r2.) and (r2.), heating resistors (r2.) and (r3.), etc. etc., the seams between each block (T I
, T 2 , . . . T,), there were problems such as vertical line interference, that is, thin vertical lines appeared.

The present invention was made to solve this problem, and an object of the present invention is to provide a thermal printer device that eliminates fluctuations in print density.

[Means for Solving the Problems] In the thermal printer device according to the present invention, heating resistors that are energized at the same time are distributed and arranged every nth heat generating resistor.

[Function] In this invention, the heating resistor that is energized at the same time is
By distributing and arranging each piece.

Significantly improves print density changes.

[Embodiment] FIG. 1 is a diagram showing the configuration of a thermal link device according to an embodiment of the present invention. In fig.

It is the same as the one shown in FIG. 2 except that the heating resistors that are energized at the same time are distributed and arranged every n pieces.

In the thermal printer device configured as described above, when performing a printing operation, the operation is the same as the conventional one except that each strobe pulse is simultaneously applied to every n heating resistors.

[Effects of the Invention] As described above, the present invention includes a shift register that temporarily stores print data, a latch circuit that latches the print data from the shift register, and each output signal from the latch circuit. and a plurality of AND circuits that perform AND with the control signal.

A plurality of heat generating resistors are provided which are energized by the output signals of the AND circuits, and the positions of the heat generating resistors which are energized at the same time are distributed, which has the effect of greatly improving print density changes.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a thermal link device according to an embodiment of the present invention, Fig. 2 is a block diagram of a conventional thermal printer device, Fig. 3 is an operation waveform diagram of the above conventional example, and Fig. 4 is a block diagram of the above conventional example. FIG. 5 is a diagram illustrating the causes of print density fluctuations in print density unevenness when printing with a conventional thermal printer device. In the figure, (3)... shift register, (4)...
・Latch circuit, (5)...NAND circuit, (r,,)~
(r , , )...A heating resistor.

Claims (1)

[Claims] A shift register that temporarily stores print data, a latch circuit that latches the print data from the shift register, and a plurality of AND circuits that take the AND of each output signal from the latch circuit and each control signal. and a plurality of heat generating resistors energized by the output signal of each of the AND circuits, the heat generating resistors being distributed at predetermined intervals every time each control signal among the plurality of control signals is applied. A thermal printer device characterized by simultaneously energizing.