JPS6335432B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to thermal recording in which exothermic recording is performed on a thermal imaging paper, and particularly to thermal recording in which multi-point recording is performed in a wide range such as the width of the recording paper.

In such thermosensitive recording, for example, N=
Since the number of recorded dots is large (1728 dots), one end and the other end of the heating element that conduct electricity to the recording section are connected in common, and each part of the heating element is energized in a time-sharing manner.

Conventionally, since the time t for recording one dot is long, for example, 2 to 5 msec, for example, as shown in FIG.
216 groups (1 group 1728/216 = 8 dots)
Each group is divided into 8 heat generating sections, and one end of each group is connected in common to form the first set of 216 common connection lines 1 ₁ to 1 ₂₁₆ and the first set connected thereto.
216 terminals P ₁ to _{P 216} are formed, and the other ends of the heating elements at corresponding positions in each group are commonly connected to form a second set of eight common connection lines 2 ₁ to 2 ₈ . 216 image signal heating circuits are connected to each of the first set of terminals P ₁ to _{P 216} , and eight group selection signals are connected to each of the second set of terminals P ₁ to _{P 8} . Each of the heat generation energizing circuits is connected. In this case, the total number of heat generating circuits or drivers is:
216+8=224 pieces.

When recording is performed by dividing the recording paper into groups in this way and continuously feeding the recording paper, as shown in Figure 2, the dots shift sequentially within each group (set), and the dot shift is largest at the boundary between the sets, and here appears to be cut off.

An object of the present invention is to make such discontinuities less likely to appear.

In order to achieve this object, the present invention alternately starts from the center of the heat-generating parts in each set, and sequentially starts from the right side, then the left side, or from the left side to the right side. Energizes heat generation. That is, within each group, the devices at the ends of the group are energized to generate heat, starting from the center of the group. For example, as shown in Figure 3, for the first set, R ₄ −
Heat is energized in this order: R ₅ −R ₃ −R ₆ −R ₂ −R ₇ −R ₁ −R ₈ . The same applies to other groups.

By energizing the recording as described above, as shown in FIG. 3, the dot misalignment at the boundary between the sets becomes smaller and no discontinuity appears.

FIG. 4 shows the main configuration of a recording energizing circuit that performs recording in the order shown in FIG. 3. 1st set of terminals P ₁
~ _P216 each has a transistor _Tr1 ~ _Tr216
Their respective emitters are connected and their collectors are commonly connected to the positive power supply. An image signal (recording "1") is applied to the bases of the transistors Tr ₁ to Tr ₂₁₆ from a 216-bit serial-in/parallel-out shift register 5 via an amplifier 3 and a latch 4. This shift register 5 has 1728
An image signal is provided at a predetermined sampling rate from a bit serial-in/serial-out shift register 7. An image signal for one line (1728 pixels) is given to the shift register 7 via an OR gate 8 and an AND gate 9, and a shift output is sent via an OR gate 8 and an AND gate 10 until recording for one line is completed. It is input in a circular manner. The output end of an inverting amplifier 11 (when the input is " ₁ ", the output is connected to ground or a negative power supply) is connected to each of the second set of terminals S1 to _S8 ,
Each output line of a decoder 12 is connected to each inverting amplifier 11, and a count code of a counter 13 is applied to this decoder 12.

A timing circuit 14 controls opening and closing of AND gates 6, 9 and 10, applies clock pulses to shift registers 5 and 7, and clears and counts up counter 13. This timing circuit may be a combination of logic elements such as a counter, logic gate, flip-flop, frequency divider, etc., or a microprocessor.

The recording energizing operation will be explained below, mainly focusing on the operation of the timing circuit 14. The timing circuit 14 requests the image signal sending side to transfer the image signal for one line, opens the AND gate 9 (turns on), gives a shift pulse to the shift register 7, and transfers the image signal for one line.
When the image signal for one line is stored in , the AND gate 9 is closed (off), the AND gate 10 is opened (on), and a shift clock (1728 steps shift) is applied to the shift register 7. Assuming a shift of (1 pixel), the 4th pulse of the shift clock, the 12th pulse, etc.
The AND gate is opened (turned on) every 8i-4th pulse, and the pixel signal of the 8i-4th pixel of the first line is taken out by the AND gate 6 and serially input to the shift register 5. After all 216 pixel signals of the 8i-4th pixel are stored in the shift register 5, AND gates 10 and 6 are closed, the pixel signal of the 8i-4th pixel is latched in the latch 4, and the counter 13 is set to 1 dot. Recording time, e.g. 2msec,
Counts up at the cycle of . When you finish this,
This means that all of the 8i-4 pixels have been recorded.
Next, the latch 4 is cleared, the gate 10 is opened, and the shift pulses are sent to the shift register 7, while the shift pulses 5, 13, 8i-3
Open the AND gate 6 for each number, and this time turn to the number 8i-3.
The pixel signal of the pixel is stored in the shift register 5 and latched in the latch 4 to cause the counter 13 to count up. As a result, recording of the 8i-3rd pixel is performed.

Next, similarly, the shift register 7 is circularly shifted to record the 8i-5th pixel. Similarly, the 8i-2nd pixel, the 8i-6th pixel, the 8i-1st pixel
Recording of pixels, 8i-7th pixel and 8i-0th pixel is performed.

This completes the recording of one line. The recording from the second line onwards is also the same as described above.

As described above, in the present invention, the heat generating portions within each group are energized to generate heat not in the order in which they are arranged, but in a manner that gradually distributes the heat from the center to the left and right in the direction of the boundary, so that large dot misalignment at the boundary between the groups can be prevented. It never occurs and no discontinuity appears.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram showing the structure of one heat-generating recording head, and FIG. 2 is an enlarged plan view showing the dot distribution recorded by the conventional method with the recording head. FIG. 3 is an enlarged plan view showing the dot distribution recorded by the recording method of the present invention. Figure 4 shows
Implementing the method of the present invention to produce the record shown in FIG. 3 1
FIG. 2 is a block diagram showing the configuration of two devices. 1 ₁ to 1 ₂₁₆ , 2 ₁ to 2 ₈ : common connection line, P ₁ to _{P 216} ,
_S1 to _S8 : terminal, _R1 to _R1728 : heating element (heating part), 11: amplifier, 4: latch, 5, 7: shift register, 6, 9, 10: AND gate, 8:
Orgate.

Claims (1)

[Claims] 1 Arrange the heat generating elements in a direction that intersects the feeding direction of the recording paper, divide the heat generating elements into n groups with m heat generating parts in this arrangement direction as one set, and divide the heat generating parts at corresponding positions in each set into n groups. In thermal recording, a specific set of heat-generating parts are commonly connected and energized to generate heat at one point by selective energization based on the image signal of the commonly-connected heat-generating parts. A heat-sensitive recording method characterized in that heat generation is energized in sequence starting from the center, then the right side, then the left side, or the left side and the right side.