JPH0810168B2 - Electronic thermometer display method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a display method for an electronic thermometer.

(B) Disadvantages of the Prior Art The conventional electronic thermometer immediately shifts to the measurement mode when the power switch is turned on, and has only the normal measurement mode as the operation mode. However, in such a thermometer, if the circuit function is not normal, an erroneous measurement is made, and there is no means for displaying that the displayed value is an erroneous measured value when the erroneous measurement is performed. . Therefore, the conventional electronic thermometer has a problem that the reliability of the temperature measurement accuracy is poor.

(C) Object of the Invention An object of the present invention is to provide a display method for an electronic thermometer, which enables self-diagnosis of circuit function for each use in a short time and allows an operator to measure the body temperature with peace of mind. .

(D) Configuration and Effect of the Invention In the present invention, a display means including a plurality of display elements, a switch, a temperature detection element, a reference resistance, and the temperature detection element or the output of the reference resistance are processed to display the temperature. A display method for an electronic clinical thermometer, comprising: a temperature measuring means for measuring; and a control means for displaying the corresponding temperature on said display means based on the output of this temperature measuring means, said control means comprising the following (a)-( The display means is controlled in the step (c).

(A) in response to the operation of the switch, turning on all of the display elements of the display means in preference to the temperature measuring means; and (b) after the step (a), the reference resistor is turned off. A step of displaying a predetermined temperature value obtained through the temperature measuring means on the display means for a predetermined time, and (c) after the step (b), the temperature detecting element is obtained through the temperature measuring means. Displaying the temperature to be displayed on the display means.

According to the above configuration, when the switch operates, first of all, the display elements are turned on in priority to the temperature measuring means. Thereby, the operator can confirm whether or not a part or the whole of the display element has a failure. If there is no failure in the display element, there is almost no possibility of erroneous display of the temperature due to the failure of the display element in the subsequent operation, and the display of the predetermined temperature numerical value and the measured body temperature is performed by the temperature measuring means. It can be seen that it depends on whether or not the measurement operation works properly.

After confirming the lighting of the display element, a predetermined temperature value obtained from the reference resistance through the temperature measuring means is displayed for a predetermined time, so that the operator can confirm in advance whether or not the thermometer operates correctly before the measurement. .

Due to the above display sequence, the operator knows that there is a failure in the display means if all the display elements do not light up immediately after the switch operation. If is not displayed, it means that there is a failure in the temperature measuring means. Therefore, it is possible to easily and smoothly detect whether the display unit is out of order or the temperature measuring unit is out of order, and the operator can start measuring the body temperature with peace of mind. Further, since the person inspecting the failure of the thermometer can detect the failure of the display means and the failure of the temperature measuring means separately, it is possible to easily and quickly know the cause of the failure of the thermometer.

If you turn on all lights or perform a test display such as a predetermined temperature display only after the temperature measurement, the normal operation of the thermometer can be confirmed at the end. Some operators will not feel reassured. However, in the present invention, because of the above-described display order, the operator can safely start the body temperature measurement.

Furthermore, the display order of the test display before the temperature measurement is
Since there is a predetermined temperature numerical value display after all lighting, even from the psychological aspect of the operator, at the time of display of the predetermined temperature numerical value
You can get ready to measure body temperature and get ready for a smooth measurement. On the contrary, if there is a full lighting test display after the predetermined temperature numerical value display, the operator is checking the temperature display by the first predetermined temperature numerical value display, so the full lighting test display is displayed. There is a risk of momentary psychological upset and confusion as to whether or not the circuit has failed at that point, and the preparation for measurement may be delayed, but this is not the case with the present invention.

(E) Description of Embodiments FIG. 1 is a block diagram of an electronic thermometer showing one embodiment of the present invention. In the figure, the thermistor (temperature sensitive resistor)
One ends of the Rx and the reference resistor R are commonly connected and connected to a power supply (not shown) having a power supply voltage, and the other ends thereof are connected to a capacitor C whose one end is grounded via a switch SW. The switch SW is a switch that is switched according to the output of the flip-flop FF1, and is configured to switch to the thermistor Rx side when the Q output of the flip-flop FF1 is present, and to the reference resistor R side when there is no Q output. There is. The reference resistance R has a resistance value when the temperature-sensitive resistance Rx is, for example, 37.0 ° C. The switch circuit 14 includes a push button switch (not shown) for instructing the start of measurement.
It outputs an oscillation start signal to the oscillator 1 and the clock oscillator 5, and also outputs a function test start signal to the function test circuit 15. Further, the switch circuit 14 outputs a display test signal for turning on all the lights of the display 13 to the driver 12 for a certain period of time after the push button switch is pressed. Functional test circuit 15
Receives the clock signal from the clock oscillator 5 and outputs the output for a fixed time as a reset signal to the flip-flop FF1 via the OR circuit 16.

The oscillator 1 is an oscillator that oscillates at a frequency substantially determined by the time constant of the capacitor C and the thermistor Rx or the reference resistor R, and its output is given to the counter 2. Counter 2
Is a No-adic counter capable of counting up to a predetermined number No, the output of which is given to the latch circuit 3 and the overflow output thereof is given to the delay circuit 4 and the latch circuit 7. On the other hand, the output of the clock oscillator 5 which oscillates at a predetermined clock frequency fc is given to the counter 6. The output of the counter 6 is given to the latch circuit 7 and the comparison circuit 8. The clock oscillator 5, the counter 6, the latch circuit 7 and the comparison circuit 8 constitute a time measuring means for measuring the time until the counter 2 overflows. The latch circuit 7 is a holding circuit for holding the count value which uses the overflow output of the counter 2 as a strobe signal, and the output thereof is given to the comparison circuit 8. The comparator circuit 8 compares these two types of input signals and produces an output when both inputs match. The output is given to the delay circuit 9 and further given to the latch circuit 3 as a strobe signal. The output of the delay circuit 4 is given to the flip-flop FF1 as a set signal and also given to the counters 2 and 6 via the OR circuit 10 as a clear signal. The output of the latch circuit 3 is given to the decoder 11 and the read-on memory ROM. The read-on memory ROM is a memory in which the temperature value corresponding to the input is stored, and the temperature information output is displayed by the display 13 via the driver 12.

FIG. 2 is a circuit diagram showing an example of the oscillator 1 and its peripheral portion. As shown in the figure, the capacitor C has a discharge resistor R1.
The inverters 17 and 25 and the MOS transistor 18 are connected via the. Here, the inverter 25 has a hysteresis characteristic, and the inverter 17 does not have a hysteresis characteristic. The outputs of the inverters 25 and 17 are given to the set input terminal and the reset input terminal of the flip-flop FF2 via the gate circuits 19 and 20, respectively. Flip Flop
The Q output of FF2 is the counter 2 and the MOS transistor described above.
Given to 18 gates. The oscillation start signal from the switch circuit 14 is applied to the CL terminal of the flip-flop FF2.

FIG. 3 is a block diagram showing the switch circuit 14. In the figure, the power supply voltage V _DD is introduced to the D input terminal of the flip-flop FF3, and each C of the flip-flops FF3 and FF4 is introduced.
The divided clock signal CLS is applied from the clock oscillator 5 to the LK terminal. The Q output of flip-flop FF3 is applied to the D input terminal of flip-flop FF4. Q output of flip-flop FF4 is CL of flip-flop FF5
It is given to the K input terminal and the NOR circuit 22, and its output is given to the NOR circuit 21. The D input of the flip-flop FF5 is given from the output of the flip-flop FF5, and its Q output is given to the NOR circuits 21 and 22. The output terminal of the NOR circuit 21 is connected to the D input terminal of the flip-flop FF6, and the clock signal is applied from the clock oscillator 5 to its CLK input terminal. The outputs of the aforementioned push button switches (not shown) are connected to the CLK input terminals of the flip flops FF3, 4, and 6. The Q output of the flip-flop FF6 is supplied to the function test circuit 15 as a function test start signal and to the oscillator 1 as an oscillation start signal, and the output is supplied to the clock oscillator 5 as an oscillation start signal. The function start signal and the oscillation start signal to the oscillator 1 correspond to the Q output "0" (low), and the oscillation start signal to the clock oscillator 5 corresponds to the output "1" (high). The output of the NOR circuit 22 is given to the driver 12 as a display test signal. This display test signal is a NOR circuit
Corresponds to 22 outputs "1".

FIG. 4 is a block diagram showing the function test circuit 15.
In the figure, a counter 24 receives a clock signal from the clock oscillator 5 and a function test start signal via the inverter 23, and counts for a fixed time. Then, the count-up signal is output from the count-up output of the counter 24 to the S input terminal of the flip-flop FF7. The output of the inverter 23 is also given to the R input terminal of the flip-flop FF7, and the output of the flip-flop FF7 is given to the R input terminal of the flip-flop FF1 via the OR circuit 16 as described above. The flip-flops FF1 and FF7 are reset-priority flip-flops.

Next, the measurement operation of this electronic thermometer will be described.
FIG. 5 is a waveform diagram showing a terminal voltage waveform of the capacitor C. Now, assuming that the switch SW is on the reference resistance R side,
The capacitor C is charged via the reference resistor R, and the terminal voltage thereof gradually rises. When the terminal voltage reaches the ON voltage V ₂ of the inverter 25, the flip-flop FF2 is set, the MOS transistor 18 is turned on, and the capacitor C is discharged through the resistor R ₁ . When the below-point voltage decreases and reaches the off voltage V ₁ of the inverter 25, the flip-flop
FF2 is reset and recharged. The charging time Tc is Is represented by When R ₁ <R, Rx, the discharge time can be ignored. Therefore, the oscillation frequency fo of the oscillator 1 is (However, I will keep it. ). Counters 2 and 6 are simultaneously cleared to count the output pulses of oscillator 1 and clock oscillator 5, respectively. When the count value of the counter 2 reaches the predetermined number No, the count value of the counter 6 is held in the latch circuit 7 by the overflow output. By the way, since the time until the counter 2 overflows is No / fo, assuming that the clock frequency of the clock oscillator 5 is fc (for example, 33 KHz), the count value of the counter 6 held in the latch circuit 7 is Can be expressed as Next, the overflow output of the counter 2 is applied to the OR circuit 10 with a small time delay by the delay circuit 4 to clear the counters 2 and 6 and set the flip-flop FF1. By inverting flip-flop FF1, switch SW is switched from the reference resistor R side to the thermistor Rx side. When the thermistor Rx is connected, the oscillation frequency fx of the oscillator 1 is obtained by converting R in the following equation (2) into Rx. (However, ) (When connected to the thermistor Rx). After that, the counter 2 starts counting the output pulses of the oscillator 1 having the oscillation frequency fx. On the other hand, the counter 6 again counts the output pulses of the clock oscillator 5. Here, the clock frequency is fc '. When the counter 6 reaches the count value represented by the equation (3), the comparison circuit 8
Detects a match between the two and temporarily holds the count value of the counter 2 at that time by the latch circuit 3. When the count value held by the latch circuit 3 is Nx, the count value (f'cNx / fx) counted by the counter 6 is held by the latch circuit 7 within the time (Nx / fx) when the counter 2 counts up to Nx. Is equal to the count value fcNo / fo (value of equation (3)). Therefore, the following formula is established.

Assuming that the clock frequency does not change during switching between the reference resistor R and the thermistor Rx, fc and fc ′ are equal. Therefore, by modifying equation (4) and substituting equations (2) and (2) ′, , The following equation holds.

By the way, the resistance value of the thermistor Rx can be expressed by the following equation.

However, Ro: Resistance value at absolute zero To: B: Boltzmann constant T: Absolute temperature Although the switch SW is composed of a semiconductor switch, if the reference resistance R and the thermistor Rx have almost the same resistance value, the switch ON resistance and OFF Since the values of the voltage V ₁ and the on-voltage V ₂ are considered to be equal, it can be set that k ₁ = k ₂ . Substituting equation (6) into equation (5) using this, Is established. Rewriting this for T, Therefore, if Nx is determined, the temperature can be obtained because all others are constants. Read-on memory RO shown in FIG.
The conversion code is stored in M based on equation (7),
The Nx data held in the latch circuit 3 is given to the read-only memory ROM through the decoder 11 and the temperature information is read. The temperature information is displayed on the display 13 via the driver 12.

Next, the circuit function test operation in this electronic thermometer will be described.

Figures 6 and 7 show switch circuit 14 and functional test circuit 1, respectively.
5 is a timing chart showing the operation of 5. When the push-button switch of the switch circuit 14 is pushed, the flip-flops FF3, 4, 6 are reset at the rising timing of the input. Immediately after the reset, the function test start signal, the oscillation start signal of the oscillator 1 and the oscillation start signal of the clock oscillator 5 are output from the output of the flip-flop FF6.
At this time, the NOR circuit 22 outputs a display test signal.
That is, the push-button operation shifts to the power-on state. The time during which this display test signal is output is the 6th
As shown in the figure, it is the sum of the on time T ₁ of the push button switch and the time T ₂ provided to prevent chattering. By the way, since the time T ₂ is about 2 ¹⁰ / fc seconds, it can be said that T ₁ >> T ₂ . Therefore, the display test signal is output almost for a certain period of time while the push button switch is being pressed.
When this display test signal is given to the driver 12, all lights of the display 13 are turned on. This allows the operator to
The normal operation of the display 13 can be checked by visually confirming whether all lights of 13 are turned on. After the lapse of T ₂ time from turning off the push-button switch, the flip-flops FF4,5 are set at the falling timing of the clock signal CLS, the output of the NOR circuit 22 is inverted, and the display test signal is not output.

On the other hand, while the display test signal is being output, the function test circuit 15 receives the function test start signal via the inverter 23 and the clock signal from the clock oscillator 5,
The counter 24 starts counting. At the same time, the reset signal is given to the flip-flop FF7, and the output of the flip-flop FF7 becomes "1". This output is introduced to the R input terminal of the flip-flop FF1 via the OR circuit 16, and the flip-flop FF1 is reset.
Therefore, the switch SW remains connected to the reference resistance R side without being switched to the temperature sensitive resistance Rx side. Therefore,
The oscillator 1 is forcibly oscillated by the reference resistor R. As described above, the reference resistance R is the temperature-sensitive resistance Rx at 37.0 ° C.
Since the resistance value is set to 3, the display 13 displays 37.0 ° C. as a reference temperature value for a certain time until the counter 24 counts up. That is, the operator
The circuit function can be tested by visually confirming whether or not 37.0 ° C is displayed. In addition,
This test is performed even when the pushbutton switch is being pressed while the display test signal is being output, but since all of the indicators 13 are lit during that T ₁ hour,
The display of 37.0 ° C can be confirmed substantially after the push button switch is pushed.

Next, when the counter 24 counts up, the count-up output is given to the flip-flop FF7, and the flip-flop FF7 is set. Therefore, the reset signal to the flip-flop FF1 is released, and the normal measurement operation described above is started.

When the push button switch is pressed after the measurement is completed, the flip flops FF3, 4 are reset at the rising timing of the input. Then, after the push button switch is completely pressed, the time T ₃ provided to prevent chattering elapses, and then the flip-flop FF4 is reset and the flip-flop FF5 is reset at the falling timing of the clock signal CLS. Therefore, the Q output of the flip-flop FF6 becomes "1" and the output becomes "0", and the power is turned off. That is, flip-flop FF6
The oscillation of the oscillator 1 and the clock oscillator 5 is stopped by the inversion of the output of.

[Brief description of drawings]

1 is a block diagram of an electronic thermometer showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing the periphery of an oscillator 1 of the electronic thermometer, and FIG. 3 is a switch circuit 14 of the electronic thermometer. Circuit diagram, FIG. 4 is a circuit diagram of the functional test circuit 15 of the electronic thermometer, FIG. 5 is a waveform diagram showing a terminal voltage waveform of the electronic thermometer capacitor C, and FIG. 6 and FIG. 6 is a timing chart showing the operation of the switch circuit 14 and the function test circuit 15 of the thermometer. 1 ... Oscillator, 13 ... Display, 14 ... Switch circuit, 15 ... Function test circuit, R ... Reference resistance, Rx ... Temperature sensitive resistance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masatsugu Miura 10 No. 10 Hanazono Dodo-cho, Ukyo-ku, Kyoto City, Kyoto Prefecture Tateishi Electric Co., Ltd. (72) Inventor Hidetoshi Matsumoto No. 10 Hanazono Todo-cho, Ukyo-ku, Kyoto Tateishi Electric Co., Ltd. (56) Reference JP-A-52-77774 (JP, A) JP-A-53-69685 (JP, A) JP-A-54-156579 (JP, A) JP-A-59-30030 (JP, A) JP-B-52-27016 (JP, B2) OPERATING AND MANUAL AL 2804A QUARTZ THERM OMETER (Quartz Thermometer 2804A Instruction Manual), HEWLETT. PACKA RD COMPANY, 1980 MEDICA, 2. Jahrgang, 10. Juni 1981, Heft. 6,414-420

Claims (6)

[Claims] 1. A display means comprising a plurality of display elements, a switch, a temperature detection element, a reference resistance, and temperature measurement means for processing the output of the temperature detection element or the reference resistance to measure the temperature. A display method of an electronic thermometer having a control means for displaying the corresponding temperature on the display means based on the output of the temperature measuring means, wherein the control means displays the display in the following steps (a) to (c). A method for displaying an electronic clinical thermometer characterized by controlling means. (A) in response to the operation of the switch, turning on all of the display elements of the display means in preference to the temperature measuring means; and (b) after the step (a), the reference resistor is turned off. A step of displaying a predetermined temperature value obtained through the temperature measuring means on the display means for a predetermined time, and (c) after the step (b), the temperature detecting element is obtained through the temperature measuring means. Displaying the temperature to be displayed on the display means. 2. The electronic thermometer according to claim 1, wherein the switch is a push button switch, and when the push button switch is operated, all of the display elements are turned on. Display method. 3. In the step (a), in response to an operation of the push button, a power-on state is set, and all the display elements of the display means are turned on in priority to the temperature measuring means. The method for displaying an electronic thermometer according to claim 2, characterized in that: 4. The electronic thermometer according to claim 1, 2, or 3, wherein in the step (a), all the display elements of the display means are turned on at the same time. Display method. 5. In the step (a), all display elements of the display means are turned on for a certain period of time, and the first, second, third, or fourth aspects are included. The display method of the electronic thermometer according to the item. 6. A power-off state in response to a second operation of the push button switch, as claimed in claim 2, claim 3, claim 4, or claim 5. Display method of electronic thermometer.