JPH024533A - Thermal sensitive recording system - Google Patents

Abstract

PURPOSE:To eliminate omission of printing by overlapping adjacent heat generating elements of each group at a part corresponding to one dot to be heated when the groups are sequentially heat-generated in a time division manner. CONSTITUTION:When an enable signal ENB1 is input, drivers D16-D10 of a group 1 are operated, data d17-d10 of the group 1 of a shift register SR are applied to heat generating elements R17-R10 to be heated. Then, when an enable signal ENB2 is input, the heat generating elements R27, R26,... of a group 2 are heated similarly. Simultaneously, the signal ENB2 for the group 2 is also applied to the adjacent driver D10 of the group 1 through an OR gate OR1, the element R10 is so heated in the degree as not to generate heat, the temperature of the element R27 disposed at the end is maintained as specified, and it is recorded with dots of specified size. Thus, it can prevent omission of printing.

Description

[Detailed description of the invention] [Table of contents] a. Important industrial uses If Figure) Effects of the invention [Summary] Regarding the heat-sensitive recording method using a line-shaped thermal print head, we have developed a line-shaped thermal print head for the purpose of preventing white spots that occur at the boundaries of groups during recording. Divide into multiple groups and use a time-sharing method for each group.
In a thermal recording method that generates heat from a heat-generating element, heating the heat-generating elements of a group that generates heat simultaneously with heating the adjacent heat-generating elements of a group adjacent to this group, or heating the heat-generating elements of a group that generates heat. At the same time, heating elements in adjacent groups before and after the groove are heated.

[Industrial application field]

The present invention relates to a thermal recording system for facsimiles and various other types of thermal printers having linear thermal print heads, and more particularly to a thermal recording system that maintains the dot size at a regular size and prevents dots from falling out.

[Prior Art] Conventionally, a thermal recording method using a line-shaped thermal print head has been used in facsimiles and various other printers.

The line-type thermal recording system has a pixel density of 8d OL/mm, 300
dPI (300 tons per inch), /l0
There are some such as 0dPI.

When the overall size becomes large, such as A4 or B4, it is common practice to divide the thermal heads into groups in terms of power consumption, and apply power to each group in a time-sharing manner to generate heat. be.

[Problem to be solved by the invention]

The above-mentioned conventional devices had the following drawbacks.

(1) Self-missing in the sub-scanning direction occurs due to uneven paper feeding.

(2) If you change the group enable output method,
Due to the reduction of dots, self-missing occurs in the main scanning direction.

(3) The larger the gap in the time division of the thermal bed, the smaller the size of adjacent dots on the grip, causing white spots to occur.

The present invention has been made to solve these conventional drawbacks, and aims to effectively prevent dots from becoming smaller and eliminate self-dot dropouts.

[Means to solve the problem]

In order to achieve the above object, the present invention is as follows.

In other words, in the present invention, the cause of the dot size reduction is
This is because the dots next to the dots at the end of the group that are currently being heated are cold, so to solve this problem, heat the adjacent dots or adjacent groups to the extent that the thermal recording paper does not develop color. It is based on the principle that the dot that is currently being heated can be expanded to its normal size.

FIG. 1 is a diagram showing the principle of the heat-sensitive recording method according to the present invention, and the present invention will be explained in detail below based on this diagram.

Shift register SF? has 1,947 minutes of data manually compiled.

This shift register SR divides one line into multiple groups G, and now! For example, the group is illustrated as eight dots.

Group l is d17~d lG, group 2 is az7~
It is divided into d2°-.

Accordingly, for example, Group I is composed of eight dots of heating elements (heating resistance elements) ranging from RIT to R5 degrees, and eight drivers DR ranging from DI7 to D1 degrees.

When the enable signal ENB 1 is input, the group 1 driver l)+? ~D1° operates, so heating element R17~
Data from dl'l to d1° of group 1 of shift register SR is applied to 8 dots of R1°, and heat is generated in accordance with the data.

Subsequently, an enable signal is input to enable ENB2, and group 2 generates heat.

At this time, the driver 02 is activated by the enable signal ENB2.
1, 8 dots of ozb'- are enabled,
Data dZ for 8 dots of group 2 of shift register
7. Is d zb-d 2° the heating element R2 of group 2?
, R26''- to generate heat.

At the same time, driver D of group l. , the enable signal ENB2 for group 2 is the OR gate O.
Since the power is applied via Rt, the heating element R3° of one adjacent dot in the adjacent group of group 2 is also heated. At this time, no data is sent to the heating element RI0, and the heating element RI0 is heated to such an extent that no color develops.

Thereafter, in the same way, the heating elements are sequentially driven to generate heat for each group and recorded on the recording paper. When 1547 minutes are over, the shift register SR is reset, data for the next line is input, and the same operation is performed. Repeat.

After all, the heating elements are driven in each group while overlapping one dot at a time.

[Effect]

With the above configuration, when each group generates heat, the heating elements of the adjacent L dots of that group and the adjacent group are driven to generate heat by overlapping them to the extent that they do not produce color, so that the heat generated at the end of each group is driven to generate heat. The temperature of the element is maintained as specified.

Therefore, it is possible to always record with dots of a specified size, so that blank spots do not occur.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. Second
The figure is an explanatory diagram of a heat-generating recording method that is an embodiment of the present invention.

In the figure, SR is a shift register for inputting data, and is used to input 1547 worth of data at once. Further, this shift register S17 divides the 1547 minutes into 8 groups of 8 points each, and extracts data for each group in a time-sharing manner. Furthermore, this shift register S1 has a reset (RESI) signal, a latch (LATCH) signal, and a clock (C[
, 0CK) signals are manually input, and 1517 minutes of data (DATA) are sequentially input manually using these signals.

DR is a driver for driving the heat generating elements (heat generating resistor elements) R, 7 to R8 degrees, and is usually composed of a transistor circuit.

■,. is the power supply for the heater, 0R1-ORv is the orageto, E
NBl and -ENBo are enable signals for the above-mentioned drivers, and are enabled at low level "L".

In this example, the l group consists of heating elements for 8 dots,
(2) The line is composed of eight groups, and when each group is driven sequentially in a time-division manner, the adjacent heating elements of the previous group are overlamped by one dot and driven.

As shown in the figure, group 1 consists of 8 heating elements R17 to R0.
Dot portion and its driver [)It~D1°, shift register dl? ~d. The dots are divided into groups 2 to 8 using the same 8 dots.

and a driver D for the last heating element R1° to R2° to R7° of each group except group 8. ,D2゜,D
7° is connected to the output of an OR gate 0Rl-ORT which uses two enable signals for that group and the next group as human input signals.

Now, with one line of data set in the shift register SR, the enable signal ENB for group l is
1 (“L゛°)” is manually operated, driver D I7, D
16, -D I l, 01G operates.

Same as Gore! Then, the data d +7~d of group l of the shift register, h---d+ +~d to (8
bits) are driver D1□~D. is input to generate heat in the heating element 1217, [N1N1, Rto].

Next, when the enable signal ENB2 of group 2 is input manually, the drivers D27, D2b of group 2 are activated, and the data dZ? of group 2 of the shift register is activated.
, d26- is manually applied to the driver, and the heating elements RZ7, RZ
6- Generate heat.

At this time, the enable signal E N 132 is the OR gate O
Since the Rt is input manually, the enable signal IEN132 is
('"Lpa) also manually operates Dl., the driver of group l.

Therefore, when driving the heating elements of group 2,
The last heating element R1° of group 1, which is the adjacent +'+iT group, is also heated to such an extent that no color develops.

Similarly, group 3, group 4, group 8
The recording of 1947 minutes is completed by generating heat up to l1ll'j degrees.

Note that the heating element D11, which is the last bit of group 8,
0 means that there is no next group, so the output of the OR gate is not input.

3 to 6 are diagrams showing a thermal recording method which is another embodiment of the present invention, FIG. 3 is a block diagram of a preheating control circuit, and FIG. 4 is a diagram showing the pulses applied to the thermal head in FIG. Detailed block diagram of the generation circuit, fifth closing operation flowchart,
FIG. 6 is a timing waveform diagram.

In Fig. 3, 1 is a data receiving circuit, 2 is a main control panel circuit, 3 is a thermal print head, 4 is a data transfer circuit, and 5 is a character generator (CC) to which code data is sent. It generates characters when

When the image data is received, this CG5
doesn't work.

[5 is a thermal head application pulse generation circuit that generates application pulses for the thermal print head 3, and 7 is a line memory (RAM) that temporarily stores the reception data.

In FIG. 4, IO is a period detection circuit, which detects the period of vi return printing time. 11 is a thermal head temperature detection circuit; 13 is a group enable calculation and setting circuit that calculates and sets the width of the group enable; and 14 is a group enable output position setting circuit that determines the position of the main enable.

15 is a group enable interval detection circuit, I
O is a preheating pulse setting circuit that determines the pulse width of the auxiliary enable for auxiliary heating, 17 is a preheating pulse output position setting circuit, and 18 is a group enable output circuit, and the output signal of this circuit is sent to the thermal head. applied.

In this case, the drive circuit for the heat generating element, etc. is comprised of dedicated hardware, and is usually controlled by a microcomputer.

Therefore, as mentioned above, in order to apply a narrow auxiliary enable pulse to the groups before and after the group desired to generate heat to preheat them, the microcomputer This software can be used to control the system.

Next, the operation will be explained based on the flowchart shown in FIG.

When the data receiving circuit 1 in FIG. 3 receives the sent pig, the main control circuit 2 issues a print instruction.

The main control circuit 2 instructs the start of printing, the printing time (period! IJI), and sets the mode. This instruction is received by the print instruction receiving circuit 12 (see FIG. 4) in the thermal head application pulse generation circuit 6 and communicated to the group enable output position setting circuit 14, where the group enable output timing is set.

At the same time, from period detection circuit No. 10 +'+
In addition to measuring the time from the previous print instruction to the current print instruction, the thermal head temperature detection circuit
, the temperature of the thermistor (not shown) of the thermal head is detected, and the group enable calculation and setting circuit 13
Manipulate navel data.

The group enable calculation and setting circuit 13 sets the group enable time, that is, the width of the enable pulse.

In addition, the groove buoy pull interval detection circuit 15
Then, the group enable time is subtracted from the group enable output timing, the interval between group enables is detected, and based on this, the preheating pulse setting circuit I6 and the preheating pulse output position setting circuit 17 set the interval between enables. Set preheat pulse.

By combining the above data, etc., the output pulse is finally determined in the group enable circuit I8, and the pulse to be applied to the thermal head is output.

In this way, if the time-sharing idle time between a drive in one group and the drive in the next group is large and the dots at both ends of the group do not generate heat completely, if the time-sharing idle time exceeds a certain amount of time, the adjacent Control is performed to preheat groups up to group 8, and heat is generated for 1947 minutes.

FIG. 6 is a timing waveform diagram, and in this example, the second M
As in the embodiment shown in 1, 1947 heating elements are divided into eight groups from group 1 (Gl) to group 8 (C8), and each group is sequentially driven in a time-division manner.

Further, the driver is in an enabled state at a low level "I," and is in an inactive state at a high level "II."

First, main enable pulse 1) G at 1 (“L” level)
l is driven and generates heat. Next, by applying the auxiliary enable pulse S1 to 62, in order to enlarge the dot at the right end of G1, the entire G2 is preheated (preheated to a temperature that does not produce color).

Subsequently, by applying the auxiliary enable pulse S2 to Gl, G
Preheat the entire C1 for 2, and then use the king rice for G2~
C2 is made to generate heat by pull pulse P2.

Then, an auxiliary enable pulse S3 to G3 preheats the entire G3 for G2.

Thereafter, control is performed in the same manner up to group 8, and 1947
End the fever for minutes.

〔Effect of the invention〕

As explained above, the present invention has the following effects.

(1) When the thermal heads are divided into groups and each group generates heat sequentially in a time-sharing manner, self-disconnection occurs because the adjacent heating elements of the adjacent groups in each group are overlamped to generate heat. The printing quality etc. are improved without any problems.

(2) Since preheating is carried out in a time-divided manner to the extent that the groups before and after the group to be heated are not colored, the dots do not become small at the ends of the group and self-dropping does not occur.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the principle of the present invention, Fig. 2 is a block diagram of the first embodiment of the present invention, Fig. 3 is a block diagram of the second embodiment of the present invention, and Fig. 4 is the thermal 57 door of Fig. 3. FIG. 5 is an operational flow diagram of the second embodiment of the present invention, and FIG. 6 is an explanatory diagram of the operation of the second embodiment of the present invention. l-Data receiving circuit 2-Main control circuit 3-Thermal printer head 4-Data transfer circuit 5-Character generator 6-Thermal head application pulse generation circuit 7-Line data memory 10-All 1/1 detection circuit 11 - Thermal head temperature detection circuit 12 - Print instruction receiving circuit 13 - Group enable calculation and setting circuit 1 /I
- Group Input ■ 5 - Group Input Circuit 16 - Preheating Pulse Setting Circuit 17 - Preheating Pulse Output Position Setting Circuit I8 - Group Enable Output Circuit Pull Output Position Setting Circuit Interval Detection Between Pulls

Claims (2)

[Claims] (1) In a thermal recording method in which a line-shaped thermal print head is divided into multiple groups and the heating elements of each group are sequentially heated in a time-sharing manner, at the same time as heating the heating elements of the group to be heated, A thermal recording method characterized by heating adjacent heating elements of this group and an adjacent group. (2) In a thermal recording method in which a linear thermal print head is divided into multiple groups and the heating elements of each group are sequentially heated in a time-sharing manner, at the same time as heating the heating elements of the group to be heated, A thermal recording method characterized by heating heating elements in adjacent groups before and after the group.