JPS61182544A - Electronic clinical thermometer - Google Patents

Abstract

PURPOSE:To simplify the measurement of bodily temperature by forming a timer for clocking a prescribed period from the off time of the detecting output of a touch switch and resetting a storage means by a time-up output and using the output of the storage means as an input signal for operation start. CONSTITUTION:A metallic cap 5 as a touch part of the touch switch is earthed through a resistor R1 and connected to an input terminal 8 of an LSI4. When the cap 5 is brought into contact with a human body to measure the bodily temperature, an electric signal of about 60Hz is induced to a point A which is in contact with the cap 5 because the internal impedance of the LSI4 is extremely high, and the signal on the point A is inverted and shaped by an inverter 9. An RSFF10 is set at a point when the output of the inverter 9 is turned from HIGH to LOW, and the output of the RSFF10 is turned to HIGH, so that a measuring circuit starts to operate and continues the measurement. In accordance with the operation start of the measuring circuit, a clock signal is counted up by a timer counter 11. When the cap 5 is separated from the human body, the output of the inverter 9 is turned to HIGH, the counter 11 is counted up, the FF10 is reset, and then the measuring circuit is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to an electronic thermometer, and particularly to an electronic thermometer using a touch switch for inputting the start of operation.

(B) Prior Art Electronic thermometers that are well known in general use batteries as a power source, and are provided with a switch to turn the power on and off in order to avoid unnecessary use of the battery. Conventionally, a push button switch or a slide switch using a rubber key is used as this switch.

(C) Problems to be Solved by the Invention Since the conventional pushbutton switches and slide switches described above are not sufficient in terms of waterproofness, the inventor of the present application has developed a method to increase sealing performance and ensure waterproofness. , created an electronic thermometer that uses a touch switch as an input switch, and filed a separate application. However, in response to using this touch switch to turn on the power, if a separate touch switch is also provided for turning off the power, circuit components for the touch switch will cost 2 cents, and There is a problem that the operation of the touch switch is confusing.

In view of the above, an object of the present invention is to provide an electronic thermometer with a small number of parts and excellent operability.

(d) Means for solving the problems The electronic thermometer of the present invention has a probe (3) in the case (1).
) A touch switch consisting of a touch part (5) exposed at the tip and a circuit part (R19) whose electrical characteristics change depending on whether the touch part is contacted or not contacted from the outside, and the contact of this touch switch. It is composed of a storage means (10) which is set by the detection output, and a timer (11) which measures a predetermined period of time from when the detection output of the touch switch is turned off and resets the storage means by the time-up output.

(E) Function With this electronic thermometer, when the probe tip is inserted into the armpit and makes contact, the touch switch detects this and
The storage means is set and a switch-on signal is input to the subsequent circuit. When the probe tip □ is removed from the body,
After a predetermined time, the timer times up, the storage means is reset, and the switch-on signal is turned off.

(f) Examples The present invention will now be explained in more detail with reference to Examples.

FIG. 2 is a schematic structural diagram of an electronic thermometer in which the present invention is implemented. The electronic thermometer of this embodiment has a case 1 which includes an LSI 4 formed of a C-MOS transistor inside, a main body part 2 which is provided with a display device (not shown), etc. Tapered probe portion 3 formed
It is composed of. A metal cap 5 is provided at the tip of the probe portion 3, and a thermistor 6 as a temperature sensor is provided within the cap 5. The thermistor 6 is electrically connected to the LSI 4 of the main body 2 through a lead la7. Further, the metal cap 5 covers the thermistor 6 and also serves as a touch part of the touch switch, and is grounded inside the case 1 via a high resistance R1 of approximately IOMΩ, and is also connected to the LSI 4.

The main part of the input circuit of this electronic thermometer is as shown in FIG. 8 is connected. This input terminal 8 is connected to an inverter 9 inside the LSI 4, and the output of this inverter 9 is connected to the cent input terminal of an RS flip-flop 10. Further, a clock signal from a clock source 12 is input to the timer counter 11. When this timer counter 11 counts a predetermined number of clock signals without being reset, that is, when it measures a predetermined time, it counts up and outputs an RS signal.
The flip-flop 10 is reset. Note that the clamp diode 1 connected to the terminal 8
3.14 is provided for electrostatic countermeasures.

The RS flip-flop 10 is configured such that when its set output is on (high), it is applied as an input switch-on signal to a measuring function circuit (not shown) at the subsequent stage.

Inside the LSI 4, of course, the electronic thermometer's original measurement function circuit that performs signal processing for temperature measurement based on the signal from the thermistor 6 is built-in, but Figure 1 shows only the main parts related to the input temperature. The measurement function circuit itself is omitted because it is no different from the circuit of a general electronic thermometer.

Next, the operation of the electronic thermometer of the above embodiment will be explained.

When the tip of the probe section 3 is inserted into the armpit to measure body temperature, the metal cap 5 comes into contact with the human body.

On the other hand, since the internal impedance of the LSI 4 is very high, an electrical signal of about 60 Hz is induced at point A where the metal cap 5 comes into contact, as shown in FIG. 3A. The signal at point A is inverted and shaped by the inverter 9 as shown in FIG. 3B. At the point where the output of the inverter 9 falls from high to low, the RS flip-flop 10 is set and its output becomes high (see point 1 in FIG. 3C). This signal causes the measurement function circuit to start operating and continue measurement.

Further, when the measurement function circuit starts operating, the clock source also generates a clock signal, so that the clock signal is counted by the timer counter 11.

While the probe part 3 is inserted into the body, the metal cap 5 is in contact with the body and an induced electric signal is generated at point A, so the timer counter 11 is constantly reset and the count-up is continued. Therefore, the RS flip-flop 10 remains set without being reset.
The measurement operation continues.

When the probe section 3 is separated from the body (at time t2 in FIG. 3),
The induced electric signal at point A disappears, the output of the inverter 9 becomes high, and the timer counter 11 is no longer reset and continues counting the clock signal. When a predetermined period of time has elapsed, the timer counter 11 counts up (at time t3 in FIG. 3), and the RS flip-flop 10 is reset. This also stops the operation of the measurement function circuit.

(G) Effects of the Invention According to the present invention, measurement can be started simply by the measurer inserting the probe section into the measurement site, and when the probe section is removed from the body after the measurement, the probe section will automatically start operating after a predetermined period of time. Since it is turned off, there is no need to operate any switches, so body temperature can be measured very easily.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the main circuit parts of an electronic thermometer showing an embodiment of the present invention, FIG. 2 is a diagram showing a schematic tank structure of the electronic thermometer, and FIG. 3 is a diagram showing the circuit structure of the electronic thermometer according to the embodiment. FIG. 4 is a waveform diagram of each part of the circuit for explaining the operation. case, 3 nib part, 5: metal cap, 9: inverter, 10: RS Frisopfloop, 11: timer counter.

Claims (1)

[Claims] (1) A touch switch consisting of a touch part exposed at the tip of the probe of the case, and a circuit part whose electrical characteristics change depending on whether the touch part is touched or not touched from the outside, and contact detection of this touch switch. A storage means set by the output, and a timer that measures a predetermined time from the time when the detection output of the touch switch is turned off and resets the storage means upon time-up output, and uses the output of the storage means as an input signal for starting operation. An electronic thermometer characterized by: