JPH0548407B2 - - 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 result is required, so when using the above temperature measuring device, the user must 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).

[Problems that the invention attempts 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, and it is not particularly suitable for home use, where it is mainly used by women and girls.

[Means for solving problems]

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 results and the previous measurement results. When it is detected that the maximum value has been reached, this maximum value and the previous measurement result are displayed alternately, which simplifies the circuit configuration and downsizes the entire device.
The operation is simplified, and the current measurement result and the previous measurement result can be easily compared, making it easy to handle.

〔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
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 is a counter, 24 to 27 are NAND gates, and 28 is a NOR circuits 29 to 35 are inverters.

In the figure, an oscillator 3, counters 3, 4,
7, 8, 23, latch circuits 5, 6, 16, control unit 9, temperature measurement unit 10, display decoder 14, falling edge detection units 17, 18, notification signal generation unit 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 24, 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 operating state (reset release state) and a non-operating state (reset state) by an MCK ON signal obtained by inverting the output of the NAND gate 24 with an inverter 29.

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 the counter 4 counts the first n items, its Q output changes from “L” (low level) to “H”
Thereafter, every time the counter 4 counts n, its Q output is inverted.

On the other hand, the latch circuit 5 is set at the rising edge of the Q output of the counter 4 after the reset is released, and 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 open, 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 counter 7 is a 1-bit binary counter, and counts by one at the falling edge of the Q output of the latch circuit 5, and the Q output is inverted every time it counts. This Q output is inverted by inverter 30.
A GRST signal is formed. This GRST signal is transmitted to the latch circuit 6, counter 8, control section 9, and temperature measurement section 1.
0 is supplied to each reset terminal R of the display decoder 14, latch circuit 16, and falling edge detection section 17, and is inverted by the NAND gate 24, NOR circuit 28, falling edge detection section 18, and inverter 31, and becomes 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
The temperature measurement unit 10 controls the temperature measurement, that is, the temperature measurement timing. 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 _Qn 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 MAX・R
The signal is stored in a storage section 11 consisting of a D-type flip-flop.
Reset. 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 in the storage section 11 in place of the previously held temperature measured value. Therefore, the storage section 11 stores the largest current temperature measurement value obtained so far after the temperature measurement section 10 has been reset. Storage parts 11, 12
The data is retained even after the power is turned off. Therefore, even after the temperature measurement unit 10 stops operating, the storage unit 11 stores
It holds the maximum current temperature value obtained during its operation until it is reset by the MAX・R signal. Storage part 1
2 is the "L" MEMO signal obtained by inverting the Q output of the falling edge detector 18 with the inverter 34.
The temperature value held in the storage unit 11 is written in response to the φ signal. This temperature measurement value is written immediately before the storage section 11 is reset. Therefore, this temperature measurement value is the maximum value obtained in the previous measurement, and this is the previous measurement result as described above, and is hereinafter referred to as the previous temperature measurement value. The falling edge detector 18 inverts the output of the NAND gate 24 using an inverter 29 to obtain an MCK signal.
The ON signal switches between the reset state and the reset release state, and after the reset is released, the falling edge of the GRST signal obtained from the inverter 30 is detected and an "H" signal representing the falling edge is output. This "H" signal is inverted by the inverter 34 to form the MEMO.phi. signal.

The multiplexer 13 is controlled by an SA signal obtained by inverting the output of the NAND gate 26 with an inverter 33, selects the temperature measurement value from either one of the recording sections 11 and 12, and sends it to the display decoder 14. Here, the multiplexer 13 is
When the SA signal is “H”, the temperature measurement value from the storage unit 12 is selected, and when the SA signal is “L”, the temperature value from the storage unit 12 is selected.
The temperature measurement value from 1 shall be selected.

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 GRST 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 32 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.

In addition, although not shown in the display decoder 14,
An out-of-measurement-range detection means is provided, and if the temperature measurement value selected and supplied by the multiplexer 13 is outside the predetermined measurement range, the display 15 displays a fixed value instead of the temperature measurement value. Data representing numerical values, symbols, patterns, etc. is supplied to the display 15.

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 display decoder 14 uses the above-mentioned measurement range detection means to change the display decoder 14 to the display 1 so that when the temperature exceeds 42.0℃, the display value ``42.0℃'' is displayed.
Send data to 5. In addition, the multiplexer 13 receives the current temperature measurement value from the storage unit 11 (strictly speaking, the temperature measurement unit 1
The maximum current temperature value obtained after 0 operation. (same below), the display decoder 14 is set on the display 15 so that when the temperature is less than 32.0°C, the display value "HI°C" is displayed when the displayed value "LO°C" exceeds 42.0°C. Send data. In this way, in order to make the displayed value different between the previous temperature measurement value outside the predetermined measurement range and the current temperature measurement value from the storage unit 11, the above-mentioned measurement range detection means also uses SA.
Controlled by a signal.

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, . . . ), the notification signal CK is generated from the notification signal generating section 19 α times during this counting operation period. In this embodiment, as is clear from FIG.
is assumed to occur. 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, the above-mentioned 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 is the Q output of latch circuit 6 and Q _l of counter 8.
When both outputs are “H”, NAND gate 25
The signal is inverted by an inverter 36, and is supplied to the notification section 20 as an "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 _VDD is applied and a ground terminal, and a notification signal from an inverter 36 is connected to the base of the transistor 21.
DR is supplied.

The NOR circuit 28 which receives the GRST signal as one input has the following:
The MAX·φ signal generated by the temperature measuring section 10 is also supplied, and the output of this NOR circuit 28 is inverted by an inverter 35 and supplied to the reset terminal of the counter 23. The counter 23 is supplied with the _Ql output of the counter 8 as a clock, and counts by 1 at the falling edge of the _Ql output. When the counter 23 counts a predetermined number (12 here),
The Q _o output is inverted from "L" to "H", and the latch circuit 6 is set at the rising edge of this Q _o output.

Here, when the GRST signal is "L", the counter 23 is reset and counts by 1 for each falling edge of the _Ql output of the _counter 8.
At the rising edge of the output, the temperature measuring section 10 goes to “H”.
When the MAX·φ signal is generated, the counter 23 is reset by the MAX·φ signal. Therefore, the current temperature value obtained by the temperature measurement section 10 is stored in the storage section 1.
During the period when the temperature value is larger than the temperature value held at 1, the temperature measurement unit 10 generates the MAX·φ signal at every rising edge of the _Ql output of the counter 8, so the counter 23 outputs the _Ql output of the counter 8. The one count at the falling edge and the reset at the rising edge are repeated, and the count value of the counter 23 does not increase and the latch circuit 6 is not reset. On the contrary,
After the temperature measurement value of the temperature measurement unit 10 reaches the maximum value, the temperature measurement unit 10 does not generate the MAX・φ signal, so the counter 23 is not reset and the count value is
12, the latch circuit 6 is set.

The Q output of the latch circuit 6 is supplied to the NAND gate 26 together with the Q _l output of the counter 8, and the output is inverted by an inverter 33 to become the SA signal. Therefore, when the latch circuit 6 is not set and its Q output is "L", the SA signal is "L",
The multiplexer 13 selects the temperature measurement value from the storage section 11, but the latch circuit 6 is set to select the temperature value from the storage section 11.
When the output becomes “H”, the SA signal of counter 8
“H” and “L” alternately depending on the “H” and “L” of the Q _l output.
becomes “L”, and the multiplexer 13
The temperature measurement value from the storage unit 12 and the temperature measurement value from the storage unit 12 are alternately selected.

Next, the operation of this embodiment will be explained 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 previous temperature measurement value _N
Even when not in use, the power is normally turned on and the display section 15 is in an operating state. Further, at this time, although the counter 7 has been reset, its Q output is "L" and the GRST signal is "H". Also,
Since switch 1 is in the open state and counter 4 and latch circuit 5 are in the reset state, latch circuit 5
The output of is "H".

Therefore, since both inputs of the NAND gate 24 are "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 GRST signal is "H", the latch circuit 6, counter 8, control section 9, temperature measurement 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. Further, since the GRST signal is "H" and the output of the latch circuit 16 in the reset state is also "H", the DiPR signal obtained from the inverter 32 is "L". Furthermore, since the latch circuit 6 is in the reset state, its Q output is "L" and the SA signal is "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 such a state, when the switch 1 is operated to close, the input of the switch 1 side of the NAND gate 24 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 Q 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 GRST signal is inverted from "H" to "L". Along with this, a latch circuit 6, a counter 8, a control section 9, a temperature measurement section 10, a display decoder 1
4. The latch circuit 16 and falling edge detection section 17 are reset and activated, and the counter 8
starts counting the clocks from counter 3. Furthermore, since the GRST signal is supplied to the counter 23 via the NOR circuit 28 and the inverter 35,
The counter 23 is also reset.

Furthermore, the falling edge of the GRST 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, in the storage section 12, the previous temperature measurement value _NX ' from the storage section 11 is written in place of the previous temperature measurement value _NX '' that has been held so far.

Furthermore, since the latch circuit 6 has been reset but not set, its Q output is "L" and the SA signal remains "L", and the multiplexer 13 receives the previous measurement from the storage section 11. Temperature value
N _X ′ is selected. On the other hand, the display decoder 14
As explained earlier, the reset has been released, but the GRST signal goes to "L" and the output of the latch circuit 16 which is not set remains at "H", so the output of the NAND gate 27 goes to "H". Therefore, the DisPR signal is inverted from "L" to "H" and the display decoder 14 is preset. For this reason, display decoder 14 does not accept the output signal of multiplexer 13, but instead
All segments of the display 15 are lit.

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 25 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 GRST signal is kept at "L" as it is, and therefore the MCK ON signal obtained from the inverter 29 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". An edge is detected by the control section 9 at the rise of this Q _l output, but the control section 9
No signal sent to 0. Further, when the counter 8 counts l and the count value becomes 2l, the Q _l output is inverted from "H" to "L", and the counter 23 counts by 1 and the count value becomes 1. At the same time, the Q _n output of the counter 8 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.
A MAX.R signal is generated, and the storage section 11 is reset by this signal. As a result, in the storage unit 11, the previous temperature measurement value _NX ' is deleted and the value 0 is held.

Furthermore, since the output of the latch circuit 16 becomes "L", the DisPR signal from the inverter 32 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”, multiplexer 1
3 selects the measured temperature value from the storage unit 11, and since this measured temperature value is 0, the out-of-measurement-range detection means in the display decoder 14 causes the display 15 to display the displayed value "LO℃". is displayed. Meanwhile, the counter 8 continues its counting operation, and the count value reaches 3.
When the Q _l output is reversed from "L" to "H", the control section 9 detects this reversal and controls the temperature measuring section 10.
send a signal to.

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 value _N1 is larger, the temperature measurement unit 10 sets the MAX value of "H".
Generates a φ signal and sends it to the storage unit 11, and stores the current measured temperature value N.
1 is written into the storage unit 11. As a result, indicator 1
5 shows the displayed value “T ₁ ℃” corresponding to this current temperature measurement value N ₁
is displayed.

At the same time, this MAX·φ signal is supplied to the reset terminal R of the counter 23 via the NOR circuit 28 and the inverter 35. As a result, the counter 23 is reset and its count value becomes zero. Further, when the counter 8 counts by l and the count value reaches 4l, the Q _l output is inverted from "H" to "L", and the counter 23 counts by 1 and the count value becomes 1.

Furthermore, when the counter 8 counts by l and the count value reaches 5l, the _Ql output inverts from "L" to "H", and the temperature measuring section 10 detects the temperature immediately before the rising edge of this _Ql output. Compare the current temperature measurement value N ₂ and the temperature measurement value N ₁ held in the storage unit 11,
When the current temperature measurement value _N2 is larger, the storage unit 11
It is rewritten to the current measured temperature value _N2 . For this,
The display 15 displays a display value "T ₂ °C" corresponding to this current temperature measurement value N ₂ . Further, the counter 23 is reset by the MAX·φ signal generated at this time.

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 value of the temperature measurements obtained so far after the reset is held, and during the period when the temperature measurement value does not reach the temperature of the measurement target (for example, body temperature), the temperature measurement unit 10 is The temperature value held in the storage unit 11 is updated every time the temperature is measured, and the display 1 is updated accordingly.
The display value displayed in 5 is also updated.

In addition, the counter 23 counts 1 each time the Ql output of the counter 8 falls, but during the period in which the temperature measurement values held in the storage unit 11 are sequentially updated, each rising edge of the _Ql output of the counter 8 The counter 23 is reset by the MAX·φ signal generated from the temperature measuring section 10. Therefore, during this temperature value update period, the counter 23 alternates between reset 1 and the counter, and the count value alternately becomes 0 and 1 and does not increase. As a result, the latch circuit 6 is not set, so the multiplexer 13 continues to select the current measured temperature value from the storage section 11, and the value displayed on the display 15 is updated.

In this way, the temperature measurement section 10 continues to measure the temperature, and if the current temperature measurement value _NX obtained is larger than the temperature measurement value NX _-1 held in the storage section 11, _The temperature value _N
If _the temperature value _N For this reason, the counter 23 is not reset and the counter 8
1 more count at the next falling edge of the Q _l output. As a result, the counter value of the counter 23 is 2.
becomes.

Then, if the current temperature value obtained by the temperature measurement unit ₁₀ does not become larger than the temperature measurement value N Okay, the current temperature value _N ), the counter 23 is not reset,
The count value increases by one at each falling edge of the _Ql output of the counter 8. In addition, the display 15 displays a display value "T ₁ ℃" corresponding to the maximum current temperature measurement value _N
continues to be displayed.

Then, as shown in FIG. 2b, the counter 23
When the counter value of becomes 12, its Q _o output becomes “L”
to "H". The latch circuit 6 is set at the rising edge of this _Qo output, and its Q output is inverted from "L" to "H". This Q output “H”
The condition persists until latch circuit 6 is reset.

When the Q output of the latch circuit 6 becomes "H", the output of the NAND gate 26 becomes "L" when the Q _l output of the counter 8 is "H", and the Q _l output of the counter 8 becomes "L".
becomes “H” when SA is output from inverter 33.
The signal changes from "H" to "L" as the _Ql output of the counter 8 changes from "H" to "L". As a result, the multiplexer 13 receives the current temperature value from the storage unit 11.
N _X and _the previous _{temperature measurement} value N

On the other hand, when the Q output of the latch circuit 6 becomes "H" and the Q _l output of the counter 8 is "H", the notification signal CK from the notification signal generator 19 passes through the NAND gate 25 and is inverted by the inverter 36. , “H”
is supplied to the transistor 21 of the notification section 20 as the notification signal DR. By the way, when the Q _l output of the counter 8 is "H", the SA signal is " _H " and the multiplexer 13 selects the previous temperature measurement value N Temperature value
Since the display value "N _{X '} ℃" corresponding to N _X ' is displayed, the display value " _{N N}
During the display period, the notification signal DR is supplied to the notification unit 20 and the notification device 22 makes a sound.

This determines the temperature of the object to be measured (this is the maximum value of the current temperature measurement, and in the case of a thermometer, the body temperature).
It is possible to know through the notification that the results have been obtained,
Further, this temperature and the temperature obtained during the previous measurement are displayed alternately and clearly distinguishable from each other by notification. Therefore, the current measurement result can be accurately known, and the current and previous measurement results can be compared and the trend of temperature change can be accurately grasped.

Thereafter, when the switch 1 is operated to close, the counter 4 and the latch circuit 5 are reset again, and as explained earlier, the Q output of the latch circuit 5 is inverted from "H" to "L". Te counter 7
counts by 1, its Q output is inverted from “H” to “L”, and the GRST signal changes from “L” to “H”.
to be reversed. However, since the input on the switch 1 side of the NAND gate 24 is “L”, MCK・ON
The signal is also maintained at "L". Therefore, even if the switch 1 is closed, the above operation continues.

As the GRST signal becomes "H", the latch circuit 6, counter 8, control section 9, temperature measurement section 10,
The display section 14, latch circuit 16 and falling edge detection section 17 are reset to a non-operating state,
The display section 15 displays a blank display. Further, since the Q output of the latch circuit 6 becomes "L", the NAND gate 25 is cut off, and the supply of the notification signal DR to the notification section 20 is stopped.

When the switch 1 completes its operation and becomes closed, the counter 4 and latch circuit 5 are reset, and the output of the latch circuit 5 is inverted from "L" to "H". Counter 7 is not affected by this, so
The GRST signal remains at "H". Then, by opening the switch 1, the two inputs of the NAND gate 24 become "H", the MCK ON signal is inverted from "L" to "H", and the oscillator 2, counter 3, and falling edge detector 18 and the notification signal generating section 19 are reset and become inactive.

In this way, all of the circuits become inactive, and the entire device stops operating. At this time, the falling edge detectors 17 and 18 output signals of MAX and R, respectively.
Since the MEMO/φ signal is not generated, the memory unit 11 is not reset and retains the maximum current temperature value _NX obtained during the current measurement, and the memory unit 12 stores the previous temperature measurement value _NX. ′ is maintained. This current temperature measurement value _NX held in the storage section 11 is written into the storage section 12 at the time of the next measurement, and is used as the previous temperature measurement value.

In addition, when displaying according to the above-mentioned previous temperature measurement value N _{X ′} , if this previous temperature measurement value N
Needless to say, the display value "32.0° C." or "42.0° C." is displayed on the display 15 by the out-of-measurement-range detection means provided at 4.

Further, as the annunciator 22, a buzzer can be used, but it is not limited to this, and a lamp can also be used.The melody signal is read out by driving an IC memory that stores a melody with the annunciation signal DR, and drives a speaker with this. Any alarm device may be used, including one that generates a melody.

Furthermore, in the above embodiment, the falling edge detection unit ₁₈ writes the previous temperature measurement value N
Instead, a rising edge detection section is used, and the GRST signal is supplied to the reset terminal with a slight delay, and the rising edge of the GRST signal is used to detect MEMO and
By forming a signal, the temperature value held in the storage unit 11 when the temperature measurement unit 10 stops operating may be written into the storage unit 12 as the previous temperature measurement value for the next measurement. .

Furthermore, in the above embodiment, the notification signal DR is supplied to the notification unit 20 during the entire display period of the display value _{" T} A rising edge detection section of the Q output of the latch circuit 6 is provided to generate an "H" pulse of a constant width from the rising edge of the Q output, and by supplying this pulse to the NAND gate 25, the displayed value on the display 15 is The notification signal DR may be supplied to the notification unit 20 only during the period when the alternating display of "T _X °C" and "T _X 'C" starts.

It is clear from the above description that even if the switch 1 is operated before the temperature measurement value obtained by the temperature measurement section 10 reaches the maximum, the entire device will stop.

As described above, in this embodiment, it is possible to start and stop the operation of the entire device by operating a single switch 1, and it is also possible to automatically notify that the current temperature value has reached the maximum. This makes it easier to confirm. If this embodiment is a thermometer, a conventional mercury thermometer may be placed under the armpit, for example.
It is assumed that the body temperature will be displayed if it is inserted for more than a minute, but in this example, it is possible to accurately confirm that the body temperature is displayed.
The reliability of displayed values is greatly improved.

Further, in this embodiment, when the current temperature measurement value reaches the maximum, this maximum current temperature measurement value and the previous temperature measurement value are displayed alternately, and the notification makes it easy to distinguish between them. Because of this, it is possible to easily and accurately compare the two and determine trends in temperature changes.

In short, this embodiment is very easy to operate and provides accurate measurement results. Furthermore, since a single switch is operated, there is no possibility of erroneous operation, the circuit configuration is simplified, and the entire device can be made smaller.

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. Furthermore, the current temperature measurement value _NX and the previous temperature measurement value _NX ' are also displayed alternately for about 0.7 seconds each, but this is sufficient for recognizing 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.

〔Effect of the invention〕

As explained above, according to the present invention, measurement can be started and stopped by operating a single switch, and required measurement results can be easily recognized. Since this measurement result and the measurement result obtained from the previous measurement are displayed alternately in a distinguishable manner, the operation is simplified, making it easier to handle and preventing erroneous operation. It is possible to know reliably and accurately, and moreover, it is possible to easily know trends in temperature changes.

Furthermore, since a single switch is provided, the circuit configuration is simplified and the device can be made smaller.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the temperature measuring device according to the present invention, and FIGS. 2a and 2b are timing charts for explaining the operation of FIG. 1. 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, 23
……counter.

Claims (1)

[Claims] 1 A switch that can be operated from the outside, a first determination section that determines the open/close operation state of the switch, a temperature measurement section that starts operating in response to the output of the determination section, and holds measurement data of the temperature measurement section. a first storage section that stores the temperature measurement section; a second storage section that stores the measurement data held in the first storage section when the temperature measurement section starts or ends the operation of the temperature measurement section; a detection unit that detects that the measurement data of has reached a maximum value; a multiplexer that selects the measurement data read from the first and second storage units according to the output of the detection unit; a display section that displays a display according to the selected measurement data, and when the temperature measurement section starts or stops operating, the first storage section stores the current measurement data by the temperature measurement section in the first storage section. The second storage section holds the previous measurement data by the temperature measurement section, and the multiplexer stores the data read from the first storage section during a period when the current measurement data by the temperature measurement section increases sequentially. and after the current measurement data by the temperature measurement section reaches a maximum value, the measurement data read out from the first and second storage sections are alternately selected. A temperature measuring device characterized by: