JPH0224155A - Recording system in thermal recorder - Google Patents

Abstract

PURPOSE:To simplify a device in construction by using sampled raw data for managing a heat history and conducting a data generation taking the heat history into consideration at the time of generating printing data. CONSTITUTION:Raw data sampled in an A/D converter 10 are sequentially stored in a memory for a last value 12 and a memory for a last value but one 13 through a data update logic part 11. In a value relation judgement logic part 14, the value relation is compared among past two data and present data, i.e. three raw data. The result of the judgement is transmitted to an interpolation address decision operating part 15 and, therein, addresses for the interpolation data are generated. In an interpolation data generation part 16, dot printing data connecting between the obtained addresses is generated. This printing data is transferred at high speed to a thermal head 18 through a thermal head transfer part 17 within one printing cycle. Then, a dot printing is conducted by heating elements corresponding to the printing data.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a recording method for a thermal recording device, and particularly to management of its thermal history.

[Summary of the invention]

The present invention is a thermal recording device that samples an input signal and records dots using a heating element with a dot number corresponding to the sampled value. By generating data in consideration of thermal history, the device configuration is simplified.

[Conventional technology and issues]

A thermal recording device, ie, a recorder using a thermal head, samples an analog input signal one by one and performs dot recording using a heating element with a dot number corresponding to the sampling value.

In this thermal head, if the same heating element is continuously driven, the element may deteriorate due to heat accumulation or burnout may occur. In order to avoid such continuous application of energy to the same heating element, the next dot to be driven is determined based on past energy application information (thermal history) to the heating element, but this is not possible in conventional methods. It is necessary to have as many memories (history depth) as necessary for management (history depth) that correspond one-to-one to heating elements, and to control them (for example, ``Japanese Patent Application Laid-Open No. 58-21118'').
etc).

In other words, in the past, arithmetic processing between print data corresponding to already generated heating elements was performed at the time of data transfer to the thermal head, resulting in a complex circuit configuration, resulting in an increase in the number of parts and an increase in the size of the device. There were issues that led to this.

The present invention was made in view of this point, and uses sampled raw data to generate #! ) The purpose is to simplify the configuration of the device by managing the history and making it possible to implement this using software.

[Means to solve the problem]

In order to achieve the above-mentioned object, the method of the present invention analyzes the raw data of two consecutive past samples in a heat-sensitive recording device that samples input signals and records dots using heating elements with dot numbers corresponding to sampling values. At the same time, the dot address of the corresponding heating element is determined from the raw data, the magnitude relationship between the past data and the current raw data is compared, and from the judgment result, continuous printing ( draw i!ii) generate data;
This print data is transferred at high speed to a thermal head within one print cycle to perform dot recording.

[Effect]

In this way, by managing the thermal history at the same time as printing data is generated, the configuration can be simplified, resulting in a significant reduction in the number of parts.Moreover, this method can be easily implemented using software. This also reduces the number of parts.

〔Example〕

Examples of the recording method of the present invention will be described below.

In controlling the thermal history of a thermal head, the printing pulse impact coefficient of each heating element is as follows for a general thermal head:
The maximum is 25%. Therefore, thermal history control can be satisfied if, for example, the maximum applied pulse width is set to 1 m5 ec in a printing period of 2 m5 ec, and it is ensured that the same dot is not driven more than twice in a row. The basis of this method is to generate such printing (drawing) data.

In this embodiment, a case where this operation is realized by software will be explained with reference to FIG.

It should be noted that throughout the entire process, print data is processed on a single buffer for transferring data from thermal to RAD.

Each process will be explained below.

(1) Clearing the previous data First, the previous print data remaining on the hand printer 7 is cleared. This is not done for the entire area of the buffer (it is cleared between the dot addresses for the previous and two previous data).

(2) Generation of dot address A dot address of the corresponding heating element is generated from the raw data input after A/D conversion. In addition, in this method,
The input raw data is subject to thermal history management, and the raw data for the past two consecutive times, that is, the previous time and the time before the previous time, are stored and held.

The input raw data is then compared to see if it is the same as the previous value, and different processing is performed depending on whether the data is the same or different.

(3) Processing of the same continuous data (baseline data) This is a process when print data of the same level is continuous, such as a part of the baseline of an electrocardiogram.

In this case, data can be sent to the thermal head buffer at the position corresponding to the dot address generated in (2), but in order to reduce the load on the same dot, print (heat generation) data is written every second time. That is, data transfer to the same dot is performed in accordance with the printing cycle as shown in FIG.

Furthermore, in this operation, by generating additional data for the dot address generated in (2), a thick baseline can be drawn. This additional data is indicated by a circle in the figure.

(4) Interpolation processing of change data This is a process when print data of different levels are consecutive, such as the QR3 complex of an electrocardiogram waveform.

In this way, if there is a difference between two consecutive pieces of data, they are interpolated and used as dot print data on the thermal head. Interpolation is performed using the previous and previous dot addresses and the current dot address. Based on the magnitude relationship between the raw data corresponding to these three, the four
There are two interpolation patterns.

For explanation purposes, the illustrations are from the previous article and the previous article.

And the raw data of this time are OLD and PREV respectively.

Display as CUR.

a. Monotonically increases or decreases (Figure 3A) If the data increases or decreases in a monotone like this,
0LD-PR at each printing timing as shown in the figure.
By generating interpolation (printing) data as shown by the solid line between EV and between PREV and CUR, continuous printing to the same heating element does not occur.

b. Phenomenon of partial return of current data (Figure 3B) In this pattern, where current data partially returns to previous interpolated data, there is a portion that overlaps with previous interpolated data (dotted line area in the figure). If this is printed, the heating element will be turned on twice in a row during this time, which is inconvenient, so clear data is entered in the dotted line part as the interpolated data this time. The remaining parts have already been cleared with the aforementioned +11. That is, by not printing this time, it is possible to prevent continuous load from being applied to the same dot.

C0 Return phenomenon that exceeds the previous interpolation amount (Figure 3 C) When the current data returns to exceed the previous interpolation data, the dotted line part in the figure overlaps with the previous printing, but the solid line part Therefore, in this case, interpolated data is generated between 0LD-CUR, that is, the dotted line portion is not printed, and only the solid line portion is printed.

d. Example of alternately interpolating between two different points (Fig. 3D) When the data at the upper and lower levels are alternately consecutive like this, if you perform the processing as described above, all the data will become blank. Therefore, when such a state continues,
Remember that the blank space has been set, and print data will be generated alternately.

(5) Updating history data After generating print data on the buffer as described above, the raw data is finally replaced as in the previous time - same previous time this time.

The above operations from +11 to (5) are all performed by software for each printing cycle, and the processing time is 150 to 200μ.
It is about sec. In actual processing, in a printing cycle of 2 m5ec, after data is transferred from the thermal to the RAD, print data is generated on the buffer by the processes (1) to (5) described above. That is, the print data generated on the buffer this time is transferred at high speed to the thermal head within the next print cycle, and dot recording is performed by the heating element corresponding to the print data.

In this way, with this method, even after data is transferred to the thermal head during a printing cycle of 2 m5ec, it can be processed sufficiently, so a single buffer for generating and holding print data can be used for both reading and writing. .

FIG. 4 shows an example of a configuration when the system of the present invention is implemented in hardware.

That is, the raw data sampled by the A/D converter (10) is sequentially stored in the previous value memory (12) and the previous value memory (13) via the data update logic unit (11), and the past two data are The raw data of this time and the raw data of this time are input to the magnitude relationship determination logic section (14) and the interpolation address determination calculation section (15), and the dot address of the corresponding heating element is generated from this raw data.

The magnitude relationship determination logic unit (14) compares the magnitude relationship between the past two raw data and the current three raw data, and the determination result is sent to the interpolation address determination calculation unit (15) to determine the dot of the interpolated data. An address is generated.

Then, in the interpolation data generation section (16), continuous dot print data is generated between the dot addresses obtained as described above, and this print data is transferred via the thermal head transfer section (17) within one print cycle. Thermal head (1
8), and dot printing is performed by the heating element corresponding to the print data.

As explained above, in this method, thermal history management is performed simultaneously when printing data is generated, so that the configuration can be simplified compared to the conventional method. In other words, in the past, thermal history was managed dot-by-dot when already generated print data was transferred to the thermal head, resulting in a complicated circuit configuration, but with the method of the present invention, thermal history is Raw data is used for history management, and thermal history is taken into account when generating print data, so there is no need for a complicated circuit configuration as in the past, and this results in a significant reduction in the number of parts and a downsizing of the device. Weight reduction can be achieved.

Moreover, this method can be implemented using either software or hardware; when implemented using software, the number of parts can be further reduced, and when implemented using hardware, real-time processing is possible. Moreover, since the structure is simpler than the conventional method, the device can be made smaller and lighter.

In addition, the method of the present invention can flexibly handle data other than analog signals (such as characters), and can be applied to printers that only print rather than recorders. Since management can be performed simultaneously, it is advantageous for realizing a small and lightweight printer.

(Effects of the Invention) As described above, according to the recording method of the thermal recording device of the present invention,
Since print data generation and thermal history management are performed simultaneously, the circuit configuration can be simplified compared to conventional systems, resulting in a significant reduction in the number of parts and making the device smaller and lighter.

Furthermore, since the present invention is a method that can be easily implemented using software, the number of parts can be reduced from this point of view as well.

[Brief explanation of the drawing]

FIG. 1 is a flowchart explaining the method of the present invention, FIG. 2 is an explanatory diagram of processing for baseline data, FIGS. 3A-D are diagrams for explaining print (between Jii) data generation for change data, and FIG. 4 is a block diagram showing a hardware embodiment of the method of the present invention.

Claims (1)

[Claims] In a thermal recording device that samples an input signal and records dots using a heating element with a dot number corresponding to the sampling value, it stores and holds raw data for two consecutive past samples, and records data from the raw data. Find the dot address of the corresponding heating element, compare and judge the magnitude relationship between the past data and the current raw data, generate continuous print data between the obtained dot addresses, and print this print data within one print cycle. A recording method for a thermal recording device that transfers dots to a thermal head to record dots.