JPS61130817A - Thermal plotter for recording chromatogram - Google Patents

Abstract

PURPOSE:To enable the continued recording of a chromatogram regardless any disconnection in thermosensitive elements, by providing the thermosensitive elements with a heat insulated detection means. CONSTITUTION:When a data '1' is latched with a latch circuit 9 passing through a CPU bus 8, a transistor 11 is turned ON through a resistance 10 and current flows to one thermosensitive element 2 of a thermosensitive head module 1 via a current detection resistance 12. The elements 2 is heated with the current to discolor a thermosensitive recording paper contacting the element 2 to record. At the same time, the voltage across the resistance 12 is amplified 7, the output thereof is inputted into a comparator 6 to be compared with a specified voltage and a signal of '1' or '0' is outputted to the CPU bus 8 through a gate circuit 5. In this manner, the voltage across the resistance 12 inserted in series into the element 2. Thus, whether the element 2 operates normally or not, namely, the disconnection of the element 2 can be detected and in case of disconnection, the element 2 can be switched over to another element 2 to record a chromatogram continually.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a thermal plotter for recording chromatograms, and more particularly to a thermal plotter for recording chromatograms, which is suitable for continuing recording even if a heat-sensitive element during recording is disconnected. It is something.

[Background of the invention]

Conventionally, chromatograms have been recorded using pen recorders, but in recent years, recording of chromatograms using a thermal grommet, which can record not only chromatograms but also characters, etc., has become popular.

Thematic ivy can be roughly divided into parallel recording methods and serial recording methods, but the serial recording method is generally used because high resolution is required for recording chromatograms.

The thermal head module, which is the recording section, is made up of a plurality of thermal elements, and is designed to record information on the thermal recording paper in that area by selectively applying current to these elements and heating them. In the case of line recording such as a chromatogram, only 18 of these plural heat-sensitive elements are used (Japanese Patent Laid-Open No. 52-94294, Japanese Patent Laid-Open No. 54-337).
52, JP-A-57-1766).

By the way, due to the structure of the heat-sensitive element, there is a possibility that the wire may be worn out due to friction with the recording paper, or the wire may be burnt out due to overheating. However, recording of chromatograms using conventional thermal plotters is carried out by fixedly using only one heat-sensitive element of the heat-sensitive head module, and there is no means to detect disconnection of the heat-sensitive element, so If the heat-sensitive element is disconnected, there is a drawback that further recording is no longer possible.

Moreover, it takes more than an hour to record a single sample, and because it takes a long time, it is often operated unmanned, so if recording is interrupted midway, there will be a large loss of time and samples. .

[Purpose of the invention]

The present invention has been made in view of the above, and its purpose is to continue recording even if the heat-sensitive element during recording is disconnected.
An object of the present invention is to provide a chromatogram recording thermal plotter capable of recording a chromatogram.

[Summary of the invention]

A feature of the present invention is that a disconnection detection means is provided in the valley heat-sensitive element of the heat-sensitive head module.

[Embodiments of the invention]

The present invention will be explained in detail below using the embodiment shown in FIG. 1 and FIG. 2.

FIG. 1 is a block diagram showing an embodiment of a thermal plotter for recording chromatograms of the present invention.

In FIG. 1, 1 is a thermal head module, 2 is each thermal element of the thermal head module 1, 3 is a memory, 4 is a microprocessor (CPU), 5 is a gate circuit, 6 is a comparator, and 7# is a differential amplifier. , 8 is a CPU path, 9 is a latch circuit, 10 is a resistor, 11 is a transistor, 12 is a current detection resistor, and 5 to 7 and 9 to 12 are provided according to the aK of the heat sensitive element 2.

When data "1#" is latched into the latch circuit 9 through the CPU bus 8, the transistor 11 connected via the resistor 10 is turned on, and current flows through the resistor 12t- to one thermal element 2 of the thermal head module 1. The heat-sensitive cord 2 is heated by this current, and the heat-sensitive recording paper 13 (see FIG. 2) that is in contact with the heat-sensitive element 2 changes color, thereby performing recording.

At the same time, the voltage across the resistor 12 is amplified by the differential amplifier 7, the output of which is input to the comparator 6, where it is compared with a predetermined voltage, and the signal @1" @Qll is sent through the gate circuit 5. and outputs it to the CPU spring 8.

As described above, in the embodiment shown in FIG. 1, the voltage across the current detection resistor 12 inserted in series with the heat-sensitive element 2 is compared with a predetermined voltage, and the magnitude of the current flowing into the heat-sensitive element 2 is measured. By doing so, it is possible to detect whether or not the heat-sensitive element 2 is normal, that is, to detect a disconnection of the heat-sensitive element.

Here, the latch circuit 9, the resistor 10, the transistor 10,
A configuration consisting of a current detection resistor 12, a thermal element 2, a differential amplifier 7, a comparator 6, and a gate circuit 5 is set as one unit.
Multiple pieces are available.

When recording on the recording paper 13, the CPU 4 sets data @1'' in the latch circuit 9 to drive one heat-sensitive element 2 through the CPU bus 8, and also sets the comparator 6 corresponding to the heat-sensitive element 2 being driven. The output of gate circuit 5
When the output of the comparator 6 is '1#, it is judged that normal recording is possible, and after a predetermined time, the latch circuit 9 is set to '''0#, and the power to the thermal element 2 is turned off. On the other hand, if the output of the comparator 6 is 10#, it is determined that the heat-sensitive cable 2 is disconnected, and the above operation is performed to drive another heat-sensitive element 2.

As described above, according to the embodiment of the present invention, the heat sensitive element 2
It is possible to detect a disconnection of the wire, and in the event of a disconnection, the heat-sensitive element 2 can be switched to another heat-sensitive element 2, so that chromatograms can be continuously recorded.

〔Effect of the invention〕

As described above, according to the present invention, even if the heat-sensitive element during chromatogram recording is disconnected, the chromatogram can be continuously recorded.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a thermal plotter for recording chromatograms according to the present invention, and FIG. 2 is a diagram showing recording of a chromatogram by the heat-sensitive element 4 shown in FIG. ■...gM head module, 2...thermal element, 3
...Memory, 4...CPU, 5...Gate circuit,
6...Comparator, 7...Differential amplifier, 9...Latch circuit, 11...Transistor, 12...Resistor for current detection, 13...-Thermosensitive recording paper.

Claims (1)

[Scope of Claims] 1. A paper feeding mechanism, a thermal head module including a plurality of thermal elements, a drive mechanism for driving the thermal head module in a direction perpendicular to the paper feeding direction, and a selectively arranged thermal head module for each of the thermal elements. 1. A thermal plotter for chromatographic recording, comprising a thermal head drive circuit for supplying power to a thermal head drive circuit, characterized in that each of the thermal elements is provided with disconnection detection means. 2. A patent claim in which the wire breakage detection means includes means for switching the heat-sensitive element to another heat-sensitive element in the heat-sensitive head module to continue recording when it is detected that the heat-sensitive element during recording is broken. A thermal plotter for recording chromatograms according to item 1.