JPS6326851B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a system of temperature measuring instruments. The purpose of the present invention is to accurately measure the temperature of an object (target) in as short a time as possible when measuring temperature using a temperature measuring device, and to notify that the temperature is being measured accurately. purpose. Furthermore, another object of the present invention is to miniaturize the above measurement system into a simple system. When measuring temperature using a temperature measuring device, it takes a considerable amount of time for the temperature sensor of the temperature measuring device to become equal to the temperature of the object to be measured (object) and to reach a state of temperature equilibrium. With conventional temperature measuring instruments, it was not possible to know when the temperature sensor was in a state of temperature equilibrium with the object to be measured, and it was not possible to know whether the displayed temperature was the correct value. As a result, I left it unattended for longer than necessary and relied on my intuition to read the temperature display. Furthermore, in recent years, electronic wristwatches with digital displays have become popular, and it has been considered to provide these electronic wristwatches with a temperature measurement function. However, because electronic wristwatches are worn on the wrist at all times, the temperature sensor inside the electronic wristwatch is at a temperature that is different from the outside temperature and body temperature. Therefore, when measuring the outside temperature with this electronic wristwatch, a temperature shield must be placed between the wrist and the electronic wristwatch, or the electronic wristwatch must be removed from the wrist to prevent body heat from being transferred. The latter case is the simplest, and it is also convenient because if you want to measure your body temperature, you only need to hold the electronic wristwatch under your armpit. However, the problem here is that it is necessary to quickly and accurately measure the temperature or body temperature, and at the same time notify the user that accurate temperature measurement has been completed. This also applies to the general conventional temperature measuring instruments mentioned above. The present invention provides a solution to these problems and provides a new temperature measuring device. Hereinafter, specific examples will be explained with reference to the drawings.
FIG. 1 is a block diagram of a specific example of a conventional quartz crystal thermometer. 101 is a crystal oscillator sensor, 102
103 is a gate circuit, a counter circuit, etc. for counting the frequency of 101 and converting it into temperature, and 104 is a decoder/driver circuit for driving the display 105. In this conventional example, it is assumed that the temperature of the sensor 101 is _T0 . This sensor allows
Consider the case of measuring the temperature of an object at temperature T′.
As shown in FIG. 2, the temperature T of the sensor 101 comes into contact with the object to be measured at time t=0 and gradually changes from temperature T ₀ to temperature T' of the object to be measured. sensor 1
The temperature T of 01 is given by the following equation. Here, T ₀ : Temperature of the sensor just before measurement (when t=0) T' : Temperature of the object to be measured T : Temperature of the sensor at time t t : Elapsed time k : Constant However, here, the object to be measured The heat capacity of the sensor is much larger than that of the sensor, and it is assumed that there is no temperature change during measurement. Figure 2 shows equation (1), but in order to measure the temperature T' of the object to be measured, normally
It takes several seconds to several tens of seconds. This varies not only depending on the value of k but also due to the influence of convection and the like. Therefore, obtaining sufficiently reliable temperature measurements requires a considerable amount of time. Another inconvenience is that the measurer does not know how much time it will take to obtain an accurate measurement value. The present invention solves the above drawbacks,
This temperature measuring instrument has a system that performs accurate measurements in the shortest possible time, notifies the measurer of the completion of the measurement, and at the same time allows the measurer to know how accurate the measurement is. FIG. 3 is a block diagram of a specific example of the temperature measuring device according to the present invention. In the figure, 301 is a crystal oscillator sensor, 302 is a standard frequency generator, 303, 306
is a gate circuit, counter circuit, etc. that counts the frequency from the crystal oscillator sensor and converts it to temperature.
304 is a decoder/driver circuit for driving the display body 305. 307 is a circuit that stores the count value converted into temperature by 306; 308 is the value of the memory 307 and the count value 30
If the difference between the two is greater than a predetermined value, the counting result of 306 is written into the memory of 307. At the same time, the value 306 passes through the decoder and driver 304 and is displayed on the display 305. If the above difference is less than a predetermined value, a signal is sent to the decoder/driver 304 to cause the display 305 to blink. At the same time, the gate of the drive circuit 309 of the buzzer or speaker 310 is opened to make the buzzer or speaker 310 sound. The clock for ringing 310 above is obtained from 302. Sampling interval for temperature measurement (tn-tn-1 in Figure 4)
is determined by the reference signal 302. Further, the difference between the count value of 306 and the value of the memory 307 (Tn-Tn-1 in FIG. 4) is preset to 308 in advance. FIG. 4 is a diagram for explaining the operation when temperature measurement is performed using the temperature measuring device shown in FIG. 3 of the present invention. At time t=0, the temperature of the object to be measured at temperature T' begins to be measured. The temperature is sampled and measured at time intervals of tn−tn−1, and the temperature difference Tn−
When Tn-1 becomes the formula Tn-Tn-1≦ε (2) for a predetermined value ε, a signal indicating the end of the measurement is given at 305 in Fig. 3.
Or issue by 310. The value of ε is determined by the comparator 3
This value is preset to 08. Next, how much the measured temperature Tn deviates from the true temperature T' of the object to be measured with respect to the set value of ε is as follows. From equation (1) From equations (3) and (4) From equations (2) and (3), From equations (3) and (7), As will be explained later in Fig. 5, in reality, k2 is the equation (9), so for example, if we take the equation ε=0.1 [℃] (10) tn−tn−11.4 [sec] (11), then (8 ) The right side of equation ε becomes equation (12), and equation (8) becomes approximately Tn−T′≦ε=0.1 equation (13). Therefore, in this case, 0.1 for the true value
The user can also see that the temperature is being measured with an accuracy of °C. In order to further improve the measurement accuracy, ε may be made smaller according to the above discussion. The value of k is
The value is determined by the measuring instrument, so it is best to measure it in advance. This gives ε, k, tn−
Since tn-1 is known, the measurement accuracy for the true value can be determined from equation (8). Therefore, the third aspect of the present invention
By using the temperature measuring device shown in the figure, when the measurement is completed, the user is notified that the measurement has been completed, and at the same time, the user can also know the accuracy of the measured value, making it possible to perform accurate measurements in a short time. It became. FIG. 5 is a block diagram of another embodiment of the present invention. This figure shows the TM resonator (Patent Application Certificate 52-
107478, 52−107480, 53−23903, 53−149499,
53-149500, etc.) (Oscillator detailed in patent application document 55-174170)
This is an example. As stated in claim 4 of the present application
The TM oscillator and twin-mode oscillator refer to those described in the above patent specification by et al., respectively. The system of FIG. 5 and FIG. 6 showing the operation timing of FIG. 5 will be described below. The names and functions of each part in Figure 5 are as follows. 501 is an oscillation circuit shown in FIG. 6, which will be described later;
2 is the clock output _F of 501 (frequency of bending vibration)
503 is a counter that measures seconds, minutes, hours, days, etc.; 504 is a decoder and driver that drives the liquid crystal display device 503, etc.; The above series of blocks collectively constitute a clock function. On the other hand, the functions of a crystal thermometer are configured as follows. △= _F − _T ≒ output from 501 oscillator
Const− _T ( _T is the frequency of torsional vibration) The voltage waveform of the frequency signal is
If the series resonant resistance of _{the T} vibration of the TM crystal resonator is large, it will contain a large amount of _F component, but in order to prevent malfunction due to this, the △ waveform has a frequency several times that of △.
Sampling is performed at a sampling frequency of 10 to 20 KHz to cut out high frequency components and obtain a Δ signal whose phase fluctuates but whose average frequency is constant. This function is performed by a sampling circuit 508 in the figure consisting of a D-type FF. 506 and 507 are a timer and a timer time setting section, respectively, which output a timer time of time T every cycle of the clock Φ ₀₀ . (See Figure 7). Φ ₀₁ gives the minimum resolution of time T. The timer functions to adjust variations in the frequency temperature characteristics of _T of the TM crystal resonator. This adjustment is done as follows. First, the difference frequency Δ can be expressed by the following equation. △=△ ₀ + _T α (θ−θ ₀ ) (14) Formula α=−α _T = −40 to −50 PPM/℃ However, here θ is temperature, θ ₀ is, for example, θ ₀ = 0℃ α is △ The first temperature coefficient of △ ₀ , _T0 is _F when θ=θ ₀
is the difference frequency between and _T and the frequency of _T. At this time 5
The number N of output pulses of the AND circuit of No. 09 is given by the following equation: N=△ _T =△ _0T + _T0Tα (θ− _θ0 )= _N0 +ΔN(θ− _θ0 ) (15). For example, in order to set the amount of change △N in the number of pulses per 1°C of N to 10, the time T may be set so as to satisfy the following equation: △N= _T0 T・|α|=10 (16). Calculating this T for the case of a TM crystal resonator, α=40PPM/℃, _T0 =192KHz, so _T0 =7.64Hz/℃, so T=1.31sec. In this case, it is sufficient that the input clock Φ ₀₀ to the timer is 2 seconds, and the temperature measurement is repeated every 2 seconds. When △N=10, the minimum resolution of temperature measurement is
The temperature will be 0.1℃. From equation (16), it is clear that the variation in the primary temperature coefficient and _T0 of the TM crystal resonator can be adjusted by changing the timer time T. Next, 510 is an up-down counter that can be preset, 512 is an external setting terminal of 510, and formula (15) is used.
Set the N ₀ value. 511 is a circuit that memorizes the presence or absence of the carry output of the 510 counter;
17 is a differentiation circuit that generates a differential pulse Φ ₁ at the falling edge of a binary digital signal of H (High) and L (Low) of the timer output T, and 516 is a delay circuit that further delays Φ ₁ in time. . 513,514 is D
A data latch circuit 515 is a type FF, and 515 is a decoder that converts the binary numbers 513 and 514 into decimal numbers, and a driver that drives the liquid crystal display device 518. The operations of blocks 510-518 are performed as follows. Referring to FIG. 7, first, data N ₀ of 512 is preset to the counter 510 by a clock pulse of Φ ₂ . And time T is the logic level H
The counter 510 starts counting from the moment . At this time, the counter starts operating as a down counter. If the number of pulses N during the time T shown in equation (15) is N≧N ₀ , the carry offset is 5.
At the same time as the output is output from the counter No. 10, the counter becomes an up counter instead of a down counter. Further, the carry value is stored in 511. 511 may be a 1-bit counter. Also, if N<N ₀ , 51
Since 0, no signal is output, and the internal state of 511 maintains the L level state at the time of reset. 5
The operations of the counter 10 and the latch circuits 513 and 514 and the state of internal data are as shown in the lower part of FIG. In the figure, 71 indicates a count state, 72 indicates a data holding state, and 73 indicates a preset state.
The output S of the memory circuit 511 corresponds to a positive temperature when it is at L level, and corresponds to a negative temperature when it is at H level.
In this way, since the previous sampling value is stored in the memory 520, the temperature counted at each sampling time is compared with the value 520 by the comparison calculation circuit 519. As a result of the above comparison, the difference is the initially set ε (same definition as equation (2))
If the temperature is smaller than , a signal is sent to the decoder and driver 515 of the display device 318, causing the temperature indication value of the display device to blink, and at the same time, opening the gate of the driver circuit 521 of the buzzer or speaker 522, and making a sound 522. . As described above, the present invention is characterized by having a structure in which the notification mechanism operates when formula (2) is satisfied. The effect is from equation (2) to (13)
This has already been explained using the formula, and by using a TM oscillator and a twin mode oscillator as in this specific example, the structure can be made even simpler and more effective. That is, the sensor oscillator and the reference signal generator are composed of a single crystal oscillator. FIG. 6 is a diagram of another specific example of the present invention, and FIG.
01 is a detailed diagram of a portion. This figure shows the above-mentioned device used in the temperature measuring device according to the present invention.
This is an oscillation circuit that can simultaneously oscillate two frequencies of a TM crystal resonator. The names and functions of each part in the diagram are as follows. 601,
602, 604, and 605 are C-MS inverters for amplifiers, and 603 is a C-MS2 input NR circuit which serves as an amplitude modulator. 606,607,
609, 610, 611, 612 are the amplifiers,
This is for the DC bias that sets the operating point of the amplitude modulator. A capacitor 619 connecting one of the inputs and the output terminal of the NR circuit is a capacitor for attenuating frequency components of 10 KHz or more of Δ. Further, the resistor 608, the capacitor 616, the trimmer capacitor 617, and the TM vibrator 600 form an _F and _T resonance circuit. Coupling capacitor 615,6
19, diode 620, resistors 613, 614,
Capacitor 618 collectively constitutes a detector. The operating principle of this oscillation circuit is as follows. The voltage waveform at point ◎ is obtained by amplitude modulating carrier frequency _F by modulation frequency Δ. ◎The voltage waveform is _filtered by a 600TM crystal oscillator and
Superimposed waveforms of _T = _F - △ and _F + △ appear. is a loop in which the rectangular wave _F is amplified in two stages until it is saturated with the power supply voltage and returns to the input side of the amplitude modulator. and 603 in reverse phase
It splits into two loops that return to the amplitude modulator.
The voltage waveform Δ is characterized by being in phase between the terminals of the 600 TM crystal resonators. FIG. 8 is a circuit diagram of a specific example of the present invention. This figure shows a circuit 30 that compares and calculates the temperature value output from the temperature counting circuit in FIGS. 3 and 5 of the present invention with the previously sampled temperature value.
This is a specific example representing 8 and 519. time tn−1
Let Tn-1 be the temperature sampling value at Tn-1, Tn be the temperature sampling value at Tn, and let ε be the accuracy as described above. When Tn≦Tn-1+ε (25) is satisfied, a signal is sent to 304 and 504 to display the It can be notified by flashing or sounding a buzzer. In equation (25), let A=Tn equation (26) and B=Tn-1+ε (27) equation. Since the output signals of 308 and 519 are the binary signals of A above, each bit of the calculation circuit output is set as A ₀ , A ₁ , ..., Ai, and also for B as B ₀ ,
Let B ₁ ,...,Bi be made with an inverter.
Although FIG. 8 shows up to i=3, generally this circuit may be connected in cascade. The output C in FIG. 8 is High when A≦B (28), and is Low otherwise. Therefore, an operation signal is sent to the above-mentioned 308 and 519 using this C signal. Further, the memory circuits 307 and 519 may be latch circuits, which latch a value added with a fixed value. Next, FIG. 9 is a sketch of a specific example in which the present invention is applied to an electronic wristwatch. In the figure, 900 is a watch band, 901 is an electronic wristwatch body, 902 is a buzzer sound emitting part, 903 is a liquid crystal display panel, 904
is the seconds display digit, 905 is the minute display digit, 906 is the hour display digit, and 907 is 2 indicating the time display mode.
There are two dots. 908,909,910,9
Reference numerals 11 denote a display illumination lamp button switch, a display switching mode button switch, a date switching mode switch, and a stopwatch operation button switch, respectively. By pressing the button switch 909, the display mode is selected and becomes the time mode shown in this figure. Further, by pressing the button switch 909, the mode is switched to temperature measurement mode. A sketch of a specific example of this mode is shown in FIG. In the diagram, 1000 is the watch band, 1
001 is the electronic watch body, 1002 is the buzzer sound emitting part, 1003 is the liquid crystal display panel, 1004 is
Temperature display digits up to two digits below the decimal point, 1005 are temperature display digits above the decimal point. 1006 is a digit that represents the sign of the temperature; it is not displayed when it is positive, and - when it is negative.
is displayed. A dot 1007 represents a decimal point, and when the mode is switched to the temperature display mode, the dot 907 representing the time disappears and this 1007 is displayed. A symbol 1008 appears to indicate temperature measurement mode. As mentioned above, the sampling value of temperature measurement is a preset value ε
On the other hand, when the relationship of equation (2) is satisfied, the symbol 1008 blinks. At the same time, the buzzer 1002 emits a sound to notify the user. Of course, the numbers displayed are 1004, 1005, 10, just like on a regular wristwatch.
06 may blink. Next, FIG. 11 further shows a diagram of a specific example of the present invention,
10 is a diagram for explaining the operations in FIGS. 9 and 10. FIG. When an electronic wristwatch is equipped with the temperature measuring device according to the present invention described above, the temperature inside the electronic wristwatch is neither body temperature nor outside temperature. The internal temperature of the electronic wristwatch worn on this wrist
T ₀ is experimentally given approximately by the following equation. T ₀ =0.61T′+14 Equation (17) Here, T′ is the outside temperature. Now, suppose that in order to measure the outside temperature, the user presses the mode switching button 905 in FIG. 9 to switch to the temperature measurement mode, and then puts the watch in the state shown in FIG. 10, and then removes the watch from his wrist. The temperature inside the watch is from T ₀ , (1)
In order to satisfy the formula, the temperature becomes T after time t seconds,
Eventually, it converges to the outside temperature T'. After time tn,
(2) is satisfied, the buzzer sounds and the display flashes,
Suppose that it has been announced. From equation (2), Tn−T′=(T ₀ −T′)e ^−tn/k (18) Equation Tn−1−T′=(T ₀ −T′)e ^−tn−1/k (19 ) Formula Tn−Tn−1=ε (20) From formulas (18) and (19), From equation (20) From equations (9) and (10), if k2, tn−tn−11.4

[Formula] Equation (22) can be approximately transformed into ε(T'−T ₀ )e ^-tn/k (23), and becomes tn=k ln(ε/T′−T ₀ ) (24 ) Formula Now, in FIG. 11, the horizontal axis represents the outside temperature T', and the vertical axis on the right side represents the temperature T ₀ of the wristwatch determined by equation (17) at 1101. The vertical axis on the left is the temperature from the start of temperature measurement calculated from equation (24),
It represents the time tn until the end notification signal is given. Curve 1102 is when k=2, ε=0.1,
1103 is when k=2 and ε=0.5. As can be seen from this figure, k2, sampling interval
If tn-tn-11.4 (sec), the measurement accuracy is 0.1
It can be seen that it takes about 10 seconds at most to measure the outside temperature from -20°C to 60°C. It can be seen that when the measurement accuracy is set to 0.5°C (ε=0.5), sufficient measurement can be performed after about 7 to 8 seconds. This measurement accuracy is a value unique to the watch, so it may be displayed on the watch in advance, or if necessary, ε
It may be possible to change the . As described above, by using the temperature measuring device of the present invention, temperature can be measured accurately in a short time. Furthermore, the user can know the measurement accuracy and can also know when the measurement has ended. Further, by using the structure of the present invention, a temperature sensor and a reference can be combined into one, and the structure can be made simple and downsized. or,
The circuit configuration for measurement is also simple, and as in the present invention,
It can be configured on one chip using C-MOS IC. Furthermore, these features allow electronic wristwatches to be equipped with temperature measuring devices and other devices to be easily equipped, resulting in a wide range of applications.

[Brief explanation of the drawing]

FIG. 1 is a diagram of a specific example of a conventional temperature measuring device. FIG. 2 is a diagram for explaining the time required for temperature measurement using a conventional temperature measuring device. FIG. 3 is a block diagram of a specific example of the temperature measuring device according to the present invention. FIG. 4 is an explanatory diagram when temperature is measured using FIG. 3. FIG. 5 is a block diagram of another specific example of the temperature measuring device according to the present invention. FIG. 6 is a diagram of another specific example of the temperature measuring device according to the present invention. FIG. 7 is a timing diagram for explaining the operation of FIG. 5. FIG. 8 is a diagram of another specific example of the present invention. FIG. 9 and FIG. 10 are diagrams of other specific examples of the present invention. FIG. 11 is a diagram for explaining the operations in FIGS. 9 and 10. 101,301...Crystal oscillator sensor, 10
2,302...Reference frequency generator, 103,30
3,306...Temperature counting circuit, 104,304...
...Display decoder/driver circuit, 105, 30
5... Display body, 307... Memory, 308... Comparison calculation circuit, 309... Buzzer/speaker drive circuit, 310... Sound generating body, 501... Twin mode oscillation circuit, 502... Frequency divider, 503... ... Counter, 504 ... Display decoder/driver circuit,
505...Display body, 506...Timer, 507...
...Timer time setting section, 510...External setting terminal,
511... Carry storage circuit, 517... Differential circuit, 513, 514... Data latch circuit, 51
5...Decoder/driver circuit, 518...Display body, 519...Comparison calculation circuit, 520...Storage circuit, 521...Buzzer/speaker drive circuit, seventh
Figure, Φ ₀₀ ... clock, T ... timer period, φ ₁ ...
... Differential pulse, A, B ... Input signal, C ... Output signal, 900, 1000 ... Electronic watch band,
901,1001...Watch body, 902,100
2... Buzzer sound emitting unit, 903, 1003... Display body, 904... Second display digit, 905... Minute display digit,
906... Hour display digit, 907... Time mode display dot, 908, 1009... Display illumination lamp button switch, 909, 1010... Mode switching button switch, 910, 1011... Month/day switching button switch, 911, 1012 ……
Stopwatch operation button switch, 1004
... Temperature display below the decimal point, 1005 ... Temperature display above the decimal point, 1006 ... Temperature negative sign display, 1
007...Decimal point, 1008...Temperature display mode instruction, 1101...Temperature curve of the watch being carried, 1
102, 1103...Measurement time curve.

Claims (1)

[Claims] 1 Using a vibrator that simultaneously generates two different vibration mode components, outputs a first frequency signal fF whose frequency is stable against temperature changes and a second frequency signal Δf whose frequency changes in a predetermined manner against temperature changes. a frequency divider 502 that outputs a time unit signal and a thermometer control clock signal Φ01 based on the output signal of the oscillation circuit, and a time display means 50 that counts the time unit signal and displays the time.
3,504,505, a timer 506 that outputs a timer time signal T of a predetermined period based on the clock signal Φ01, with the timer time signal T as one input and the second frequency signal Δf as the other input; a gate circuit 509 that passes the second frequency Δf at a period determined by a timer time signal;
a counter 5 that counts a second frequency Δf from the gate circuit every time the timer time signal is output;
10. A first storage circuit 513, 51 that stores the counted value of the counter in synchronization with the timer time signal.
4. A second unit that stores the previous count value of the counter.
a storage circuit 520, a comparison calculation circuit 519 that compares the count values of the first storage circuit and the second storage circuit and outputs a detection signal when the difference is less than a predetermined value ε (ε≠0); and the comparison calculation circuit A temperature measuring instrument characterized by comprising a display means 518 that displays a temperature based on a detection signal of the temperature, and a time signal mechanism 521, 522 that emits a sound.