JPH0580608B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to thermometers and temperature measuring instruments for equipment observation and maintenance, and in particular, it is possible to check the result of the previous temperature measurement even while the temperature measurement is in operation. Regarding an electronic temperature measuring device with functions.

[Conventional technology]

Electronic temperature measuring instruments have been adopted in many fields in recent years, and in particular, for home use, they are rapidly becoming popular in place of conventional mercury thermometers due to their ease of use.

However, if a mercury thermometer is left in the same state after use, the measurement results obtained during the previous temperature measurement (i.e., body temperature measurement) can be checked for the next temperature measurement, whereas the conventional temperature measurement device described above The system only displayed the measured values obtained during operation, but did not have a function to check the previous measurement results. Therefore, for example, in order to know that the body temperature has risen or fallen abnormally, at least the previous measurement results are required. Do you want to remember the measurement results?
Otherwise, it was necessary to take notes, which was very inconvenient.

In order to solve this problem, an electronic temperature measuring instrument was proposed that had a memory function that retained the measurement results even after the power was turned off, and the results could be read out and displayed as needed (Published by Electronics Co., Ltd.) Digest, December 10, 1975, "CMOS IC Handbook", pp. 287-293).

[Problem that the invention seeks to solve]

The above-mentioned proposed conventional technology requires a dedicated memory switch for reading measurement results from the memory section in addition to a switch for starting the measurement operation, resulting in a complicated circuit configuration and a problem with the equipment. The overall size is large, and since two switches must be operated separately, the operation is complicated and easy to operate incorrectly.Moreover, it is difficult to use the previous measurement results read from the memory and the actual results obtained by the measurement operation. Since the current measurement results are displayed on the same display, if the above-mentioned switch is operated incorrectly, for example, the previous measurement results displayed may be mistakenly recognized as the current measurement results. Therefore, it is not particularly suitable for home use mainly used by women and girls.

[Means to resolve the problem]

This invention has been made in view of the above circumstances, and includes a first storage section that holds the current measurement result during temperature measurement operation and a second storage section that holds the previous measurement result, In addition to being able to start and stop the temperature measurement operation with a single switch operation, it is also possible to switch between displaying the current measurement result and the previous measurement result, and also displaying the previous measurement result. When displaying the results, the notification section is activated, making it possible to clearly determine whether the displayed measurement result is the previous measurement result or the current measurement result, which simplifies the circuit configuration. In addition to reducing the size of the entire device, the device is also easy to handle by simplifying operation and preventing erroneous operation.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the temperature measuring device according to the present invention, in which 1 is a switch, 2 is an oscillator, 3 and 4 are counters, 5 and 6 are RS type latch circuits, and 7 and 8 are Counter, 9 is a control section, 10 is a temperature measuring section, 11 and 12 are storage sections, 13 is a multiplexer, 14 is a display decoder, 15 is a display, 16
1 is an RS type latch circuit, 17 and 18 are falling edge detection sections, 19 is a notification signal generation section, 20 is a notification section, 21 is a transistor, 22 is an alarm, 23 to
27 is a NAND gate, and 28 to 35 are inverters.

In the figure, an oscillator 2, counters 3, 4,
7, 8, latch circuits 5, 6, 16, control section 9, temperature measurement section 10, display decoder 14, falling edge detection sections 17, 18, and notification signal generation section 19,
In each case, the signal supplied to the reset terminal R is “H”
(high level), it is in the reset state.

The switch 1 is a normally open switch that can be operated from the outside, such as a push switch, a slide switch, or a reed switch provided inside the main body case (not shown) that is operated from the outside using a magnet. positive supply voltage
Between the power supply terminal to which V _DD is applied and the ground terminal,
connected in series with a resistor. The connection point between this resistor and the switch 1 is connected to the reset terminal R of the counter 4 and the latch circuit 5 and to the NAND gate 23, and when the switch 1 is not operated (that is, in the open state), these are connected to "H". ” signal is supplied.

The oscillator 2 is a CR oscillator or a crystal oscillator, and generates a reference clock MCK. This reference clock MCK is frequency-divided by a counter 3 to a predetermined frequency and is supplied to counters 4, 8 and a display decoder 14 as a clock. Further, a plurality of predetermined count values of the counter 3 are supplied to the notification signal generation section 19. The oscillator 2 and the counter 3 are switched between an active state (reset release state) and a non-active state (reset state) by an MCK ON signal obtained by inverting the output of the NAND gate 23 with an inverter 28.

Counter 4 and latch circuit 5 indicate that switch 1 has been operated (that is, it has become closed)
It constitutes a determination section for determining. This counter 4 counts the clock from the counter 3 when the switch 1 is operated to release the reset. When counter 4 counts the first n items, its Q _o output goes from “L” (low level) to “H”
Thereafter, every time the counter 4 counts n, its Q _o output is inverted. Also, when the Q _o output of counter 4 is inverted k times, counter 4
The Q output of is inverted from "L" to "H". That is, when the counter 4 counts kn times after the reset is released, its Q output is inverted from "L" to "H", and thereafter the Q output is inverted every time it counts kn times. Note that in the following explanation, k=16.

On the other hand, the latch circuit 5 is set at the rising edge of the Q _o output of the counter 4 after the reset is released.
Its output is held at "L" unless it is inverted from "H" to "L" and reset.

The counter 4 and the latch circuit 5 are in a reset state when the switch 1 is open, and are in a reset release state when the switch 1 is closed, and each time the switch 1 is operated and becomes the closed state, the output of the latch circuit 5 is Inverted from “H” to “L”. Therefore, this Q output indicates that switch 1 has been operated by inverting from "H" to "L".

The latch circuit 6 is switched between the reset state and the reset release state by the GRST2 signal output from the NAND gate 30, and after the reset is released, the rising edge of the signal obtained by inverting the G4 signal output from the NAND gate 25 with the inverter 31 is set. is set. NAND gate 25 has counter 4
Q output and GRST1 signal are supplied. this
Only when the GRST1 signal is “H” and the Q output of counter 4 is inverted from “L” to “H”, G4
The signal is inverted from “H” to “L” and sent to inverter 3.
Since the output of 1 rises, the GRST1 signal goes “H”
Only when switch 1 is operated for a period of time and the operation duration is longer than the 16n count period of counter 4, latch circuit 6 is set and its Q
The output is inverted from "L" to "H". Therefore, the latch circuit 6 has a function of determining whether the operation duration of the switch 1 is longer or shorter than the 16n count period of the counter 4. The Q output of the latch circuit 6 is used as an SA signal to control the switching of the multiplexer 13, and is also supplied to the preset terminal PR of the counter 7 and the NAND gate 26.

The counter 7 is a 1-bit binary counter that counts by one at the falling edge of the Q output of the latch circuit 5, inverts the Q output each time it counts, and presets it at the rising edge of the Q output of the latch circuit 6. be done. The Q output of the counter 7 is inverted by the inverter 29 to form the GRST1 signal, and this GRST1 signal is inverted by the NAND gate 2
5 is also supplied to NAND gates 23 and 24. This counter 7 constitutes a selection section that selects whether to continue or stop the operation of the temperature measurement section 10, as will become clear in the description later.

The NAND gate 24 is also supplied with the Q output of the latch circuit 5. The output of this NAND gate 24 is inverted by an inverter 30 to form the GRST2 signal. This GRST2 signal is supplied to the reset terminals R of the counter 8, the control section 9, the temperature measurement section 10, the display decoder 14, the latch circuit 16, and the falling edge detection section 17, and is also supplied to the falling edge detection section 18, The signal is inverted by the inverter 33 and supplied to the NAND gate 27.

Counter 8 further divides the clock from counter 3. The Q _l output of the predetermined frequency division ratio is the control unit 9
is supplied to the temperature measuring unit 10 to control the temperature measurement, that is, the timing of temperature measurement. The Q _n output with a frequency division ratio twice that of the Q _l output is supplied to the latch circuit 16 as a set input. After the reset is released, the latch circuit 16 is set at the rising edge of the Q _n output of the counter 8, and its output is inverted from "H" to "L" and held until it is reset.
A falling edge of the output of the latch circuit 16 is detected by a falling edge detection section 17, and a MAX.R signal representing the falling edge is formed. this
The MAX.R signal resets the memory section 11 consisting of a D-type flip-flop. The output of latch circuit 16 is also supplied to NAND gate 27.

The temperature measuring section 10 starts operating when the reset is released, and measures the temperature once every cycle of the _Ql output of the counter 8. Each temperature measurement is completed immediately before the rising edge of the _Ql output of the counter 8. Temperature measuring section 10
compares the temperature value obtained by each temperature measurement (hereinafter referred to as the current temperature value) with the temperature value stored in the storage unit 11 in synchronization with the rising edge of this Q _l output. However, when the current temperature measurement value is large, MAX・φ
A signal is generated and the current measured temperature value is written into the storage section 11 in place of the previously held temperature measured value. Therefore, the storage section 11 stores the maximum temperature value among the current temperature values obtained so far after the temperature measurement section 10 has been reset.

The storage units 11 and 12 retain data even after the power is turned off. Therefore, even after the temperature measurement section 10 stops operating, the storage section 11 retains the maximum current temperature value obtained during its operation until it is reset by the MAX.R signal. The storage unit 12 stores the falling edge detector 1
The measured temperature value held in the storage section 11 is written by the "L" MEMO.phi. signal obtained by inverting the Q output of 8 with the inverter 35. This temperature measurement value is written immediately before the storage section 11 is reset. Therefore, this temperature value is the maximum value obtained in the previous measurement, and is the result of the previous measurement described above, and is hereinafter referred to as the previous temperature measurement value. The falling edge detection section 18 is switched between the reset state and the reset release state by the MCK ON signal obtained by inverting the output of the NAND gate 23 with the inverter 28, and after the reset is released, the GRST2 signal obtained from the inverter 30 is switched. A falling edge is detected and an "H" signal representing the falling edge is output. This "H" signal is inverted by the inverter 35 to form the MEMO.phi. signal.

The multiplexer 13 receives a signal from the latch circuit 6.
Controlled by the SA signal, a temperature measurement value from either one of the recording sections 11 and 12 is selected and sent to the display decoder 14. Although not shown, the multiplexer 13 is provided with a measurement range detection means, and when the selected temperature measurement value is outside the predetermined measurement range, the temperature measurement value is displayed on the display 15. Instead of values, data representing fixed numerical values, symbols, patterns, etc. is supplied to the display decoder 14.

Here, the above prescribed measurement range is 32.0℃~42.0℃
shall be. When the multiplexer 13 selects the previous temperature measurement value from the storage unit 12 and this value is less than 32.0°C, the display 15 will display the displayed value “32.0°C”.
The multiplexer 13 sends data to the display decoder 14 by the above measurement range detection means so that the display value "42.0°C" is displayed when the temperature exceeds 42.0°C. In addition, the multiplexer 13 receives the current temperature value from the storage unit 11 (strictly speaking,
The maximum value among the current temperature values obtained after the temperature measurement unit 10 is activated. ), this is the
When the temperature is less than 32.0℃, the displayed value "LO℃" will be 42.0℃.
When the temperature exceeds .degree. C., the multiplexer 13 sends data to the display decoder 14 so that the display value "HI.degree. C." is displayed. In this way, the out-of-measurement-range detection means is also controlled by the SA signal in order to make the display values of the previous temperature measurement outside the predetermined measurement range and the current temperature measurement from the storage unit 11 different.

The display decoder 14 and the display 15 constitute a display section. When the display decoder 14 is reset,
No signal is sent to the display 15, and for this reason,
The display 15 is in a blank display state in which nothing is displayed. When the GRST2 signal becomes "L" and the reset is released, the display decoder 14 decodes the output of the multiplexer 13 as long as the DisPR signal obtained by inverting the output of the NAND gate 27 with the inverter 34 is "L". However, when the DisPR signal becomes "H", it is preset and prohibits acceptance of the output of the multiplexer 13, and supplies a signal to the display 15 to light all segments. do.

The notification signal generating section 19 is a decoder, and when a count value in a predetermined range is supplied from the counter 3, it generates a notification signal CK that is "H" during the supply period. If the period during which the counter 3 counts from zero to the maximum count value is the counting operation cycle of the counter 3, then the above predetermined range is α (however,
α=1, 2, 3, . In this example, the second
As is clear from the figures and FIG. 3, two predetermined ranges are provided, and the notification signal CK is generated twice per the counting cycle. moreover,
A specific example of the notification signal CK is shown in FIG. In this specific example, assuming that the predetermined ranges set in the counter 3 are A ₁ and A ₂ , the time for the counter 3 to count the respective ranges A ₁ and A ₂ is set to approximately 0.1 seconds,
Also, after counting range A ₁ , start the next range.
There is a gap of about 0.1 seconds before the _count starts. On the other hand, the notification signal generator 19
The period during which counter 3 counts ranges A ₁ and A ₂ ,
This is detected and a notification signal CK of 2 to 4 kHz is generated. Therefore, when the counter 3 counts the range _A1 , the notification signal generator 19 outputs 2~2 for about 0.1 seconds.
Generates a 4kHz notification signal CK, then stops generating the notification signal CK for about 0.1 seconds, and then starts counter 3.
counts range A ₂ , 2~4kHz for about 0.1 seconds
The notification signal CK is generated. Notification signal generator 19
This operation is repeated in the counting operation cycle of the counter 3. It goes without saying that the period of the clock supplied from the counter 3 to the counters 4, 8 and the display decoder 14 is sufficiently shorter than the above-mentioned counting operation period. As is clear from FIG. 3, the counting operation period is set to 1/2 of the period of the Q _l output of the counter 8.

Notification signal generated from notification signal generation section 19
CK passes through the NAND gate 26 during the "H" period of the Q output of the latch circuit 6, is inverted by the inverter 32, and is supplied to the notification section 20 as the "H" notification signal DR.

The notification unit 20 includes an annunciator 22 and a transistor 21 connected in series between a power supply terminal to which a positive power supply voltage V _DD is applied and a ground terminal, and a notification signal DR from a NAND gate 32 is connected to the base of the transistor 21. is supplied.

With the above configuration, this embodiment is capable of displaying a display value according to the previous temperature measurement value at any time and for any period during use.Next, the operation of this embodiment is as follows. First, explanation will be given using the timing chart shown in FIG.

Regarding FIG. 2a, when not in use, regardless of whether the power (not shown) is turned on or off, the temperature measurement value _N
The storage unit 12 stores the previous temperature measurement value N _x ′, and when a battery is used as a power source, the power is normally turned on and the display unit 15 is in an operating state even when not in use. be. At this time, although the counter 7 has been reset, its Q output is "L" and the GRST1 signal is "H". Further, since the switch 1 is in the open state and the counter 4 and the latch circuit 5 are in the reset state, the output of the latch circuit 5 is "H" and the GRST2 signal obtained from the inverter 30 is also "H".

Therefore, since the two inputs of the NAND gate 23 are both "H", the MCK ON signal is "H", and the oscillator 2, counter 3, falling edge detector 18, and notification signal generator 19 are in the reset state. . Also, since the GRST2 signal is “H”,
Latch circuit 6, counter 8, control section 9, temperature measuring section 1
0, the display decoder 14, latch circuit 16, and falling edge detector 17 are also in the reset state, and the display 15 displays blank. Furthermore, GRST2
Since the signal is "H" and the output of the latch circuit 16 in the reset state is also "H", the DisPR signal obtained from the inverter 34 is "L".
Furthermore, since the latch circuit 6 is in the reset state, its Q output and therefore the SA signal are "L".
At this time, the multiplexer 13 receives the temperature measurement value from the storage unit 11 (at this time, the previous temperature measurement value
N _x ′) is selected.

The above is the state of each part when not in use.

In this state, when the switch 1 is operated to close, the input of the switch 1 side of the NAND gate 23 becomes "L", so the MCK ON signal becomes "L" and the oscillator 2, counter 3, and falling The edge detection section 18 and the notification signal generation section 19 are reset. For this purpose, the oscillator 2 generates a reference clock MCK, which is frequency-divided by the counter 3, and the notification signal generator 19 generates the notification signal CK.

At the same time, counter 4 and latch circuit 5 are also reset, and counter 4 counts the clock from counter 3. When the counter 4 counts n, its _Qo output is inverted from "L" to "H", and the latch circuit 5 is set at its rising edge. For this reason, the output of the latch circuit 5 is inverted from "H" to "L", and the counter 7 counts by 1 at the falling edge. Due to this count, the Q output of counter 7 changes from “L” to “H”
The GRST1 signal is inverted from "H" to "L".

Furthermore, as the output of the latch circuit 5 is inverted from "H" to "L", the output of the NAND gate 24 is inverted from "L" to "H", so GRST2
The signal is inverted from "H" to "L". Along with this, a latch circuit 6, a counter 8, a temperature measuring section 1
0, the display decoder 14, the latch circuit 16, and the falling edge detector 17 are released from reset and become active, and the counter 8 starts counting the clocks from the counter 3.

Furthermore, the falling edge of the GRST2 signal from "H" to "L" is detected by the falling edge detection section 18, and the "L" edge representing this falling edge is detected.
The MEMO·φ signal is supplied to the storage section 12. As a result, the previous temperature measurement value N _x ′ from the storage unit 11 is written in the storage unit 12 in place of the previous temperature measurement value N _x ″ held so far.

Furthermore, since the latch circuit 6 has been released from reset but not set, its Q output, and hence the SA signal, remain "L", and the multiplexer 13 receives the previous temperature measurement value from the storage section 11.
N _x ′ is selected. On the other hand, the display decoder 14
As explained above, the reset has been released, but the GRST2 signal becomes "L" and the output of the latch circuit 16, which is not set, remains "H", so the output of the NAND gate 27 becomes "H". ”
Therefore, the DisPR signal goes to “L”.
The signal is inverted from "H" to "H", and the display decoder 14 is preset. To this end, display decoder 14 does not accept the output signal of multiplexer 13, but instead lights up all segments of display 15.

Furthermore, since the Q output of the latch circuit 6 is "L", the notification signal from the notification signal generator 19
CK does not pass through the NAND gate 26 and is sent to the notification section 20.
is not supplied with the broadcast signal DR.

This state continues even after the switch 1 has been operated and is in the open state. This is because when switch 1 is opened, counter 4 and latch circuit 5 are reset, and the output of latch circuit 5 is inverted from "L" to "H", but counter 7 is not affected by this. Therefore, the GRST1 signal remains "L" as it is, and therefore the MCK ON signal obtained from the inverter 28 and the GRST2 signal obtained from the inverter 30 remain "L" as it is.
This is because it is maintained. In addition, the period of the closed state of switch 1 (i.e., the continuous operation time) is longer than the 16n count period of counter 4, and the Q output of counter 4 is reversed from "L" to "H" during the operation period of switch 1. However, since the GRST1 signal is "L", the G4 signal from the NAND gate 25 remains "H", and the output of the inverter 31 remains "L", so the latch circuit 6 is not set and remains unchanged. The Q output is kept at "L" as it is.

Meanwhile, the counter 8 continues to count, and when it counts a predetermined number l, its Q _l output is inverted from "L" to "H". The rising edge of this Q _l output is detected by the control section 9, but the control section 9
does not send a signal to Furthermore, when the counter 8 counts l and the count value becomes 2l, the
The _Ql output is inverted from "H" to "L", and its _Qn output is inverted from "L" to "H". The latch circuit 16 is set at the rising edge of this Q _n output, and its output is inverted from "H" to "L". The falling edge of this output is detected by the falling edge detection section 17 to form a MAX.R signal, whereby the storage section 11 is reset. As a result, in the storage unit 11, the previous temperature measurement value N _x ' is erased and the value 0 is held.

Furthermore, since the output of the latch circuit 16 becomes "L", the DisPR signal from the inverter 34 is inverted from "H" to "L", and the display decoder 14
The preset is released, and the output signal of the multiplexer 13 is accepted and decoded.

At this time, since the SA signal is "L", the multiplexer 13 selects the temperature measurement value from the storage unit 11, and since this temperature measurement value is 0, the out-of-measurement-range detection means in the multiplexer 13 selects the temperature measurement value from the storage unit 11. , the display value "LO°C" is displayed on the display 15.

The operating state of each part continues until the switch 1 is operated again. Meanwhile, the counter 8 continues counting operation, and when the count value reaches 3l, its _Ql output is reversed from "L" to "H", and the control section 9 detects this reversal and outputs it to the temperature measurement section 10. send a signal.

On the other hand, the temperature measuring section 10 completes the first temperature measurement immediately before the rising edge of the _Ql output of the counter 8, and when it receives a signal from the control section 9, the storage section 1
The temperature measurement value is read from 1 and compared with the current temperature measurement value N ₁ obtained by the first temperature measurement. in this case,
Since the read temperature value is 0 and the current temperature measurement value N ₁ is larger, the temperature measurement unit 10 sends the MAX·φ signal to the storage unit 11 and stores the current temperature measurement value N ₁ in the storage unit 11. write to. As a result, the display 15 displays a display value "T ₁ °C" corresponding to the current temperature measurement value N ₁ .

Furthermore, the counter 8 continues to count, and when the count value is 4l, its _Ql output is inverted from "H" to "L", and further, when the count value is 5l, the _Ql output is inverted from "L" to "H". However, at the rising edge of this Q _l output, the temperature measuring section 10 returns the current temperature value obtained just before that point.
_N2 is compared with the temperature measurement value _N1 held in the storage unit 11, and if the current temperature measurement value _N2 is larger, it is rewritten in the storage unit ₁₁ as the current temperature measurement value N2. For this reason, the display 15 displays a display value "T ₂ °C" corresponding to this current temperature measurement value N ₂ .

In this way, every time counter 8 counts 2l,
At the rising edge of the Q _l output, the temperature measurement section 10 compares the current temperature measurement value with the temperature measurement value held in the storage section 11. If the current temperature measurement value is large, the current measurement value is stored in the storage section 11. Rewrite to temperature value. Therefore, the storage unit 11
The maximum temperature value obtained so far after the reset is held, and during a period when the temperature value does not reach the temperature of the measurement target (for example, body temperature), the temperature measurement unit 10 The temperature measurement value held in the storage unit 11 is updated for each temperature, and the display 1 is updated accordingly.
The display value displayed in 5 is also updated.

After that, when the switch 1 is operated to close, the counter 4 and the latch circuit 5 are reset, and as explained earlier, the output of the latch circuit 5 is reversed from "H" to "L" and the counter is reset. 7 is 1
The Q output changes from “H” to “L”.
The GRST1 signal is inverted from "L" to "H". However, the output of the latch circuit 5 is “L”
Therefore, the GRST2 signal from the inverter 30 is held at "L", and since the input on the switch 1 side of the NAND gate 23 is "L",
The MCK・ON signal is also held at "L".
Therefore, even if the switch 1 is closed, the above operation continues.

Switch 1 continues to be closed, and finally, when counter 4 counts 16n, its Q output goes “L”.
to "H". At this time, since the GRST1 signal is “H”, the signal from the NAND gate 25 is
The G4 signal is inverted from "H" to "L", and the output of the inverter 31 is inverted from "L" to "H", and the latch circuit 6 is set by this inversion. For this reason, the Q output of the latch circuit 6 is inverted from "L" to "H", the SA signal becomes "H", and the multiplexer 13 receives the previous temperature measurement value from the storage section 12.
Select N _x ′. The display decoder 14 decodes this, and the display 15 displays a display value "T _x '°C" corresponding to this previous temperature measurement value N _x '. Note that if this previous temperature measurement value N _x ' is outside the predetermined measurement range, the out-of-measurement-range detection means in the multiplexer 13 causes the display unit 15 to display the value "32.0°C" or "42.0°C". Needless to say, is displayed.

Further, since the Q output of the latch circuit 6 becomes "H", the notification signal CK passes through the NAND gate 26, and the notification signal DR is supplied to the notification section 20. The transistor 21 becomes conductive every time the notification signal DR is supplied, and the notification device 22 is activated. Alarm 2
If 2 is a buzzer, it will be emitted continuously. The alarm 22 may be a lamp or a device that drives an IC memory that stores a melody with the notification signal DR, reads out the melody signal, and uses this to drive a speaker to generate a melody, or any alarm. can be used.

Furthermore, the counter 7 is preset at the rising edge of the Q output of the latch circuit 6, the Q output is inverted from "L" to "H", and the GRST1 signal is inverted from "H" to "L". As a result, Nand Gate 25
The G4 signal from the inverter 31 is inverted from “L” to “H” and the output of the inverter 31 is inverted from “H” to “L”.
The latch circuit 6 remains set.

This state continues even after the switch 1 has been operated and is in the open state. This means that even if switch 1 is opened, counter 4 and latch circuit 5 are reset and the output of latch circuit 5 changes from "L" to "H".
, both the GRST1 signal and GRST2 signal are held at "L", and the latch circuit 6
This is because it is held in the set state. Therefore, if the switch 1 is operated for more than 16n count period of the counter 4 while the temperature measurement unit 10 is in operation, the display 15 will display a displayed value (in FIG. , T _o+1 °C), a display value “T _{x ′} °C” corresponding to the previous temperature measurement value N
0 is activated.

Next, in FIG. 2b, when switch 1 is operated again, counter 4 and latch circuit 5 are reset, and the output of latch circuit 6 is inverted from "H" to "L". As a result, counter 7 becomes 1
The Q output changes from “H” to “L”.
At this time, the GRST1 signal is inverted from "L" to "H".
However, since the output of the latch circuit 5 is "L", the GRST2 signal remains "L", and
Since switch 1 is in the closed state, the MCK・ON signal also remains at "L". Therefore, temperature measuring section 1
0 is in the operating state, and the display section 15 indicates that the storage section 1
Display value “T _x ′℃” according to the previous temperature measurement value N _x ′ from 2
is displayed, and the notification section 20 is also operating.

When the switch 1 completes its operation and becomes open, the counter 4 and latch circuit 5 are reset, and the output of the latch circuit 5 is inverted from "L" to "H". Since the counter 7 is not affected by this, both inputs of the NAND gate 24 become "H",
The GRST2 signal is inverted from "L" to "H".

Therefore, the latch circuit 6, counter 8, control section 9, temperature measurement section 10, display section 14, latch circuit 16, and falling edge detection section 17 are reset to a non-operating state, and the display section 15 displays a blank display. When the Q output of the latch circuit 6 becomes "L", the NAND gate 26 is cut off and the supply of the notification signal DR to the notification section 20 is stopped. In addition, with the switch 1 in the open state, the 2 inputs of the NAND gate 23 become “H”,
MCK・ON signal is inverted from “L” to “H”,
Oscillator 2, counter 3, falling edge detector 18
Then, the notification signal generator 19 is reset and becomes inactive.

In this way, all the circuits become inactive, and the entire device stops operating, but at this time, the falling edge detection sections 17 and 18 do not generate the MAXR signal and the MEMO/φ signal, respectively, so the storage section 11 is not reset and holds the maximum current temperature measurement value N _x obtained during the current measurement, and the storage unit 12 holds the previous temperature measurement value N _x '. Storage part 1
This current temperature measurement value N _x held at 1 is written into the storage unit 12 at the time of the next measurement, and is used as the previous temperature measurement value.

The above is a case where the operation duration of the switch 1 is set to be longer than the 16n count period of the counter 4 while the temperature measurement section 10 is in operation, and when it is set to less than the 16n count period of the counter 4, the previous temperature measurement
The entire device stops operating without displaying the displayed value “T _x ′℃” corresponding to N _x ′. in this regard,
This will be explained using the timing chart shown in FIG.

In FIG. 3, the operation duration of the switch 1 to start the operation of the entire device is set to be longer than the 16n count period of the counter 4, but as explained earlier, the operation duration of the switch 1 is arbitrary. Therefore, in this case as well, when the entire device starts operating, the display 15 lights up all segments, displays the display value "LO℃", and then displays the current measurement from the storage section 11. Temperature value N ₁ , N ₂ ,
The display values ``T <sub>1</sub> ℃'', ``T ₂ ℃'', ``...'' are displayed in sequence according to ....

In this state, when the switch 1 is operated to close, the counter 4 and the latch circuit 5 are reset and the output of the latch circuit 5 becomes "H".
to "L". At the falling edge of this output, the counter 7 counts by 1, and the GRST1 signal, which was at "L", is inverted to "H".

At this time, switch 1 is closed, so
The MCK ON signal remains at "L", and the oscillator 2 and counter 3 operate to generate a clock. Furthermore, since the output of the latch circuit 5 is "L", GRST2 obtained from the inverter 30 is also "L", and the temperature measuring section 10, display decoder 14, etc. are operating. Furthermore, the latch circuit 6 is not set, the multiplexer 13 selects the current measured temperature value from the storage section 11, and the display 15 displays a corresponding display value.

If switch 1 is opened before counter 4 counts 16n, counter 4 and latch circuit 5
is reset, and the output of the latch circuit 5 is inverted from "L" to "H". Since counter 7 is not affected by this inversion of the Q output,
The GRST1 signal is kept at "H" as it is. As a result, the GRST2 signal is inverted from "L" to "H", and the latch circuit 6, counter 8, control section 9, temperature measurement section 10, display decoder 14, latch circuit 16, and falling edge detection section 17 are reset. It will stop working. Further, since both of the two inputs of the NAND gate 23 become "H", the MCK ON signal also becomes "H", and the oscillator 2, counter 3, and falling edge detector 18 are also reset and stop operating.

Therefore, while the entire device is operating, counter 4 is 16n.
If the switch 1 is operated for a period shorter than the count period, the latch circuit 6 is reset without being set. For this reason, the Q output of the latch circuit 6 is not inverted to "H", the display 15 does not display the display value " _T No notification signal is supplied to the device, and the entire device stops working.

As described above, in this embodiment, the operation of the entire device can be started and stopped by operating a single switch 1, and the duration of operation of this switch 1 while the entire device is operating can be changed. It is possible to select between displaying the displayed value according to the previous temperature measurement value or stopping the entire device, which simplifies the operation and makes it easier to handle, simplifying the circuit configuration and downsizing the entire device. It can be achieved.

In addition, after a period of time has passed until there is no change in the displayed value corresponding to the current temperature measurement displayed on the display 15 (in this case, in FIG. _o+1 ℃", which is the temperature of the object to be measured (for example, body temperature). Operate switch 1 to immediately display the display value "T _x ′℃" corresponding to the previous temperature measurement value N _x ′. After the temperature from the current measurement is obtained, the temperature from the previous measurement can be checked immediately, making it possible to compare the two and accurately grasp the trend of temperature change.

Moreover, when displaying the display value according to the previous temperature measurement value, at the same time, the notification section 20 is activated to clearly notify that this display value is being displayed.
Not only can it be clearly determined whether the displayed value displayed on the display 15 represents the temperature from the current measurement or the temperature from the previous measurement, but also it can be clearly determined whether the value displayed on the display 15 represents the temperature _from the current measurement or the temperature from the previous measurement. Switch 1 to display the displayed value “T _x ′℃”
The operation of the switch 1 and the operation of the switch 1 for stopping the operation of the entire device are made clear depending on whether the notification section 20 is activated or not, and erroneous recognition of displayed values and erroneous operations can be prevented.

Furthermore, when the device starts operating, all segments of the display 15 are lit, and then the display value "LO℃" is displayed, so check whether the display is operating normally. At the same time, you can confirm that the measurement has started, improving the reliability of the displayed content.

Furthermore, if the temperature value is outside the measurement range,
Since fixed numbers, symbols, patterns, etc. are displayed, it is possible to prevent unnecessary confusion from being caused to the user by displaying meaningless temperatures outside the measurement range.

In the above embodiment, if the period during which the counter 8 counts l is approximately 0.7 seconds, the display 15
The lighting period for all segments is approximately 1.4 seconds, and
The display period of the displayed value "LO℃" is about 0.7 seconds, and this is enough to recognize them. However, these numerical values and the specific numerical values used in the previous explanation are merely examples, and the present invention is not limited to these numerical values.

Further, in the above embodiment, the previous temperature measurement value _N
Instead, a rising edge detector is used, and the GRST2 signal is supplied to the reset terminal with a slight delay, and the MEMO/MEMO signal is detected at the rising edge of the GRST2 signal.
By forming the φ signal, the temperature measurement value held in the storage unit 11 when the temperature measurement unit 10 stops operating can be written into the storage unit 12 as the previous temperature measurement value for the next measurement. good.

Furthermore, in the above embodiment, the notification signal DR is sent to the notification unit 20 over the entire period in which the display value “T _x ′°C” corresponding to the previous temperature measurement value N _x ′ is displayed on the display 15.
However, the displayed value “T _x ′℃”
The notification signal DR may be supplied to the notification unit 20 for a predetermined period at the start of the display or after the display starts.This also allows the user to know that the display is performed according to the previous temperature measurement value N _x ′. It is possible to clearly distinguish between the displayed value based on the current temperature measurement value and the display value based on the previous temperature measurement value. In addition, one specific method for making such notification is as shown in FIG. Alternatively, a counter is provided that counts the edges of the _Ql output of the counter 8 and generates a Q output that is "H" for a period from the start of counting to a predetermined count value.
The Q output of this counter may be supplied to the NAND gate 26.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to start and stop measurement and display a display value according to the previous temperature measurement value by operating a single switch, which simplifies the operation. It is easy to handle, has a simplified overall configuration and can be made smaller, and is superior in that it can clearly distinguish between the temperature at the previous measurement and the temperature at the current measurement, and completely prevents erroneous operation. effect can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the temperature measuring device according to the present invention, FIGS. 2 and 3 are timing charts for explaining the operation of FIG. 1, and FIG. 4 is a notification signal of FIG. 1. FIG. 3 is a waveform diagram specifically showing a notification signal generated by the generating section. 1...Switch, 4...Counter, 5, 6...
Latch circuit, 7, 8...Counter, 10...Temperature measurement section, 11, 12...Storage section, 13...Multiplexer, 14...Display decoder, 15...Display device,
19... Notification signal generation section, 20... Notification section.

Claims (1)

[Claims] 1. A switch that can be operated from the outside, a first determination section that determines whether the switch is opened or closed, a temperature measurement section that starts operating in response to the output of the determination, and the temperature measurement section. a first storage section that holds measurement data of the temperature measuring section; a second storage section into which the measurement data held in the first storage section is written when the temperature measurement section starts or ends its operation; a second determination unit that determines the length of operation duration of the switch that is operated after the temperature measurement unit is activated; and selection of whether to continue or stop the operation of the temperature measurement unit depending on the output of the second determination unit; a selection unit to select the first and second selection units according to the output of the second determination unit;
a multiplexer that selects the measurement data read out from the storage section; a display section that displays the measurement data that is selected by the multiplexer; and a display section that displays the measurement data that is selected by the multiplexer; and a notification section that operates in response to selection of the measurement data read out from the second storage section, and when the temperature measurement section starts or stops operating, the first storage section The second storage section stores the current measurement data by the temperature measurement section, and the second storage section stores the previous measurement data by the temperature measurement section, and the display section displays the current measurement data according to the current measurement data. When the switch is operated after activation, depending on the length of the operation duration, the display on the display unit is switched from the current measurement data to the previous measurement data, and the notification unit is activated;
A temperature measuring device characterized in that it is configured to select whether to stop operation of the entire device or to stop operation of the entire device.