JPS6349456A - Thermal dot line type recording method - Google Patents

Abstract

PURPOSE:To prevent jamming due to adhering of a thermal head and a sheet, by classifying a line of dots into plural groups then carrying out recording of one line with a time difference between the groups and heating the dots in said line again simultaneously. CONSTITUTION:A line of dots are classified by (x) dots, then the first group is heated so as to carry out recording. Heating by (x) dots is repeated, and when single line recording is finished, all dots in said line are heated simultaneously thereafter next line recording is started. Every time when single line recording is completed, all dots in said line are heated simultaneously so as to bring out a condition where a sheet 2 is easily peeled from a head 1 thereafter the sheet is fed out. Consequently, the sheet can be fed easily and smoothly thus eliminating the occurrence of troubles such as jamming. Simultaneous heating of dots can be carried out in various ways as required including heating of all dots in single line, heating of only heated dots in single line, heating all dots or only heated dots only when the number of heated dots in single line exceeds a predetermined value, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for controlling a recording operation in a thermal dot line type recording apparatus.

[Conventional technology]

There are various recording methods for recording devices such as printers and facsimile machines, such as a wire dot type, an inkjet type, and a thermal type.

Among these, the thermal type presses a thermal head in which electrothermal transducers (dots) such as multiple heating resistors are arranged against a sheet (recording medium such as paper or a thin 7-inch thin plate), and prints based on the print data signal. A dot pattern is formed on the sheet surface by generating heat from each electrothermal converter.

This thermal recording device is a typical non-impact recording method and is characterized by low noise, and can be further classified into the following three recording methods.

One is a thermal method, in which a thermal sheet is used as a sheet, and the sheet is colored by the heat of an electrothermal converter to form a printing pattern. This is a thermal transfer method in which the ink coated on the ink ribbon is melted and adhered to the sheet by pressing a thermal head through the ink ribbon to form a print pattern. This is a thermal carbon copying method in which the back side is coated with carbon, and while recording is performed on the first sheet using a thermal method or thermal transfer method, the carbon is transferred and recorded onto a second regular sheet.

In addition, the types of printing devices include a serial type that prints while moving the print head in a direction perpendicular to the conveying direction of the sheet, a line type that prints one line at a time, or a page type that prints one line at a time. There are models, etc.

The present invention relates to a recording control method for a thermal type recording apparatus that performs line type recording, that is, a thermal dot line type recording apparatus.

A thermal dot line type recording device is a thermal head (thermal dot line head) that has a structure in which a plurality of electrothermal transducers such as heat generating resistors are arranged horizontally in a single row on a head substrate such as a ceramic substrate over the same length as that during recording. This is a type of printer that records data using a serial number, and has characteristics such as a much faster recording speed than a serial type, and good recording accuracy because there is no head movement, and is commonly used in facsimiles and other applications. .

FIG. 1 schematically shows the general structure of a thermal dot line type recording device.

In Fig. 1, a plurality of electrothermal transducers (dots) 3 such as heating resistors are arranged in a horizontal row on the sheet 2 side of a thermal dot line head 1 shown in transparent view. Unlike the serial method, the head amp is not turned down.

In serial printing, the head is raised during paper feeding to reduce the paper feeding load, but in dot line printing, the paper is fed during printing, and printing is performed with the head always in pressure contact. If the head is moved up, it is only done when inserting paper, and unlike serial machines, it is rare to have a drive source for moving the head up and down. In the illustrated example, a platen roller that also serves as a sheet feeding roller is used as the platen 4.

The platen roller 4 pinch-rotates in synchronization with a print signal that drives (generates heat) the electrothermal transducers (dots) 3, and records as shown in the figure while feeding the sheet 2.

However, in conventional recording devices that use such a thermal dot line method, when recording, the head 1
There was a problem in that a sticking phenomenon occurred between the sheet 2 and the sheet 2, making sheet feeding unstable and causing problems such as paper jams.

The cause of this sticking phenomenon between the head 1 and the sheet 2 is as follows.

That is, when using a heat-sensitive sheet as the sheet 2,
The surface of the sheet is coated with a chemical that develops color in response to heat, and this chemical reacts with the heat generated by the head 1 to perform recording.

This chemical has a property of sticking to both the surface of the heat-sensitive sheet 2 and the surface of the head 1 when the head 1 in contact with the chemical reacts and cools down.

On the other hand, in the thermal dot line type head 1, driving all the dots for one line to generate heat at the same time requires a large amount of power and causes a thermal load problem, so all the dots for one line are divided into multiple groups. When dividing the recording medium and recording one line, a driving method is adopted in which heat is generated at different times for each group.

For this reason, when recording the same line, the dot that first generates heat will be cooled down by the time the next recording ends, and the dot portion of the head 1 will stick to the sheet 2.

Moreover, in the line method, the dot duty of the thin line is higher than that in the serial method, so the number of dots that stick together is significantly greater than in the serial method.

Therefore, when feeding the sheet and starting a new line every line recording, a large force is required to separate the stuck sheet 2 and head 1, and the load (resistance) on the sheet 1 to feed motor becomes excessive. As a result, sheet feeding becomes unstable and malfunctions such as paper jams occur.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for controlling a thermal dot line type recording apparatus that can solve the problems of the prior art described above and can easily and effectively eliminate the problem of paper jams caused by the sticking phenomenon between the thermal head and the sheet. It is.

[Means to achieve the purpose]

The present invention uses a thermal dot line recording method that divides one line of dots into a plurality of groups, records one line at a time lag between the groups, and then simultaneously heats the dots of that line again. It accomplishes its purpose.

Simultaneous heating of dots in the above method can be achieved by causing all dots in one line to generate heat, by causing only the dots in one line to generate heat, or when the number of dots in one line exceeds a predetermined value. The method can be implemented in various ways as necessary, such as a method in which all the dots are made to generate heat or only the heat-generating dots are made to generate heat.

〔Example〕

Hereinafter, the method of the present invention will be specifically explained with reference to FIGS. 1 to 5.

In the first place, in the recording method of a line print type thermal recording device, that is, the thermal dot line method, it requires a large amount of power to generate heat for all the dots for one line at the same time. A method is adopted in which all the dots are divided into a plurality of groups, and each group is driven to generate heat step by step with a time difference, thereby recording one line.

For example, to record using 144 dots for one line, the dots are driven 2.1 times, each with 6 dots. In this case, if the heat generation time (during heat pulse) of each electrothermal transducer is 5 ms and each group is heated in turn without wrapping, it will take 5 ms to record one line.
A time of X24=120ms is required.

However, after this amount of time has elapsed, by the time the last group on the same line is heated, the first dot to be heated will have already cooled down sufficiently, and as mentioned above, the thermal head and heat-sensitive sheet will cool down to the cooled dot part. It sticks to me.

Therefore, the present invention has been developed to solve the problem (doors that have become stuck after being cooled).
He noticed that when heated again, it melts again and becomes easy to peel off, and this principle was used to complete the process.

That is, the present invention is capable of controlling a thermal dot line type recording device in such a way that one line is divided and recorded by successively generating heat, and then the dots of that line are simultaneously heated in a predetermined pulse. This is to prevent the sheets from sticking together.

The amount of heat when simultaneously generating heat again is not for recording, but simply to make it easier to peel off the stuck dots, so during that heat pulse it is more extreme than during the recording pulse (5 m5 in the example above). Can be shortened.

If the sheets are fed immediately after this simultaneous heat generation, the sheets can be easily fed and problems such as paper jams will not occur.

FIG. 2 is a block diagram of a control system for carrying out the thermal dot line type recording method according to the present invention described above.

In FIG. 2, a CPU (microprocessor) 11 of the recording device is connected to a host machine 12 such as a computer or a word processor. Receives print data signals and necessary command signals (commands).

The CPU 1 controls a sheet feed (platen roller 4 drive) motor 14 via a driver (drive circuit) 13, and controls a plurality of thermal dot line heads 1 based on a print data signal from a host machine 12. The heat generation drive of the electrothermal converter (dot) 3 is controlled.

Driving the motor 14.15 and the electrothermal converter 3
The recording operation, which consists of heat generation drive, etc., is controlled based on a program stored in a ROM attached to the CFull.

Further, a RAM having a buffer memory and the like for temporarily storing print data and temporarily storing heat generating dots in one line is also provided in the CPU II.

Various embodiments of the thermal dot line recording method according to the present invention will be described in detail below.

In the first embodiment, one line of dots is divided into multiple groups, one line's worth of recording is performed with a time difference between the groups, and then a short heat pulse is simultaneously applied to all the dots on that line. A method of generating heat is adopted.

Since the heat pulses applied at the same time are sufficiently shorter than the recording pulses, dots other than those forming the recording pattern will not be recorded. However, if there is a risk that it may be recorded due to temperature conditions, it may be necessary to make corrections.

FIG. 3 is a flowchart showing the control operation procedure of the first embodiment.

In FIG. 3, when the recording operation is started at step 100, first, at step 101, the first group of dots of one line divided into X dots is heated and recorded. Next, in step 102, it is determined whether or not recording of that line has been completed. If not, the process returns to step 101 to generate heat in the next group and repeat the recording.

When the recording for one line is completed by repeating heating of X dots, the process proceeds to step 103, where all the dots on that line are simultaneously heated, and then the process proceeds to step 104, where the sheet is fed and the recording of the next line is started. enter.

Repeat the same operation for the next line and record.

According to the first embodiment described above, every time recording for one line is completed, all the dots on that line are simultaneously heated to make the sheet 2 easily peeled off from the head 1, and then the sheet is fed. Therefore, sheets could be fed easily and smoothly, and problems such as paper jams could be avoided.

In the second embodiment, one line of dots is divided into a plurality of groups, and after 1942 minutes of recording is performed with a time difference between the groups, only the dots on one line that are heated are simultaneously subjected to short heating. A method of generating heat by applying pulses is adopted.

In this second embodiment, the heated dots (used for recording) in one line are memorized, and only the heated dots are repeatedly made to generate heat at the same time, so that in the case of the above-mentioned first embodiment, In addition to the effect of eliminating clogging by preventing sticking, there is no possibility of reheating and recording unrecorded dots.
This embodiment has the advantage that there is no need to perform temperature correction, and that power consumption can be saved more than in the first embodiment since the number of dots that are simultaneously heated is limited to the recording dots at that time.

FIG. 4 is a flowchart showing the control operation procedure of the second embodiment.

In FIG. 4, when the recording operation is started at step 200, first, at step 201, the first group of dots of one line divided into X dots is heated and recorded. When heat is generated, in step 202 it remembers which dot (number of dots) in that group was heated (
.

In the next step 203, it is determined whether or not recording of all groups of the line has been completed. If not, the process returns to step 201 and stores the heat generation and heat dots of the next group (step 202). Repeat.

When one line's worth of recording is completed by repeating heating of X dots, the process advances to step 204, where only the dots (heated dots) stored in step 202 among the dots on that line are heated again at the same time, and this heat generation is Immediately after, the sheet is fed in step 205, and then the next step 20
At step 6, the memory of the heating dots at step 202 is cleared and the recording operation for the next line begins.

Repeat the same operation for the next line and record.

In the third embodiment, one line of dots is divided into a plurality of groups, and after one line's worth of recording is performed with a time difference between the groups, the number of heated dots in one line reaches the set value. Only when this limit is exceeded, a method is adopted in which the dots are simultaneously heated.

In this case, simultaneous heating of the dots may be achieved by simultaneously heating all the dots in one line as in the first embodiment, or by heating only one dot among the dots in one line as in the second embodiment. A method may also be used in which only the dots that actually generate heat are simultaneously heated.

In other words, in this embodiment, when the dot duty of the recording line exceeds the set value, it is considered that if the number of recording (heat generating) dots in the recording line is small, the number of dots that stick together is small and the peeling resistance that causes the recording line does not occur. However, the simultaneous heat generation in the first embodiment or the second embodiment described above is performed.

Therefore, according to the third embodiment, it is possible to prevent the thermal head and the heat-sensitive sheet from sticking together and to eliminate paper jams, which is the same function and effect as the first and second embodiments. As long as the dot duty of the line is small and the above-mentioned sticking does not occur, simultaneous heat generation of the dots is omitted, resulting in an effect that power consumption can be saved accordingly.

FIG. 5 is a flowchart showing the control operation procedure of the third embodiment.

In FIG. 5, when the recording operation is started in step 300, first, in step 301, the first group of dots of one line divided into X dots is heated and recorded. When heat is generated, in step 302, which dot (number of dots) of the group was caused to generate heat is memorized.

In the next step 303, it is determined whether recording of all groups of that line has been completed, and if not, the process returns to step 301, and the next group's heating and heating dot storage (step 302) is performed. Repeat.

When one line of recording is completed by repeating heating of X dots, the process advances to step 304 to check whether the number of heated dots in that line, that is, the number of dots stored in step 302, is greater than the set value y. Determine.

If the number of memorized dots is greater than y, step 305
Proceed to step 1 and perform simultaneous heating of the dots, that is, simultaneous heating of all dots in one line or simultaneous heating of heated (memorized) dots in one line to eliminate sticking of the recorded sheet. Immediately after the sheet is brought into a state where it can be easily fed, the sheet is fed in step 306.

The number of dots memorized (generated heat) in step 304 is y
If it is determined that the sheet is smaller, the sheet is suddenly fed by jumping to step 306.

After the sheet is fed, the memory of the number of heating dots is cleared in step 307, and the process returns to step 301 to proceed to the recording operation of the next line.

Repeat the same operation for the next line and record.

According to each of the embodiments described above, in recording using the thermal dot line method, after recording a certain line with a time difference using divided heat, all dots or the heating dots of that line are simultaneously recorded with a very short pulse width. Since we have adopted a control system that reheats the sheet and feeds the sheet immediately after that, the head (heating element) and the sheet that have been stuck together can be easily separated, which prevents defects such as jams. Ta.

〔effect〕

As is clear from the above explanation, according to the present invention, the dots of the I line are divided into a plurality of groups, one line's worth is recorded with a time difference between the groups, and then the dots of the line are heated again at the same time. Therefore, there is provided a thermal dot line recording method that can easily prevent the head from sticking to the sheet and effectively prevent defects such as paper jams.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing a schematic configuration of a thermal dot line type recording device suitable for implementing the method of the present invention, and FIG. 2 is a schematic perspective view showing a thermal dot line type recording device suitable for implementing the method of the present invention. 3 is a flowchart showing the operating procedure of the first embodiment of the method of the present invention, FIG. 4 is a flowchart showing the operating procedure of the second embodiment of the method of the present invention, and FIG. 5 is a flowchart showing the operating procedure of the third embodiment of the method of the present invention. 1--Thermal dot line head, 2-
·······sheet, 3············dot (electrothermal converter), 4·············platen (sheet feeding roller). Agent: Yasushi Ooto, Patent Attorney Figure 3 Figure 4

Claims (4)

[Claims] (1) Thermal dot line type recording characterized by dividing one line of dots into multiple groups, recording one line at a time lag between the groups, and then simultaneously heating the dots of that line again. Method. (2) The thermal dot line recording method according to claim 1, characterized in that all dots in one line are simultaneously heated. (3) The thermal dot line recording method according to claim 1, wherein only the heated dots in one line are heated at the same time. (4) The thermal system according to any one of claims 1 to 3, characterized in that the dots are simultaneously heated only when the number of heated dots in one line exceeds a set value. Dot line recording method.