JPH0731085B2 - Temperature measuring instrument - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermometer and a temperature measuring device for observing and maintaining a device, and in particular, a function for confirming a previous temperature measurement result prior to a temperature measurement operation. The present invention relates to an electronic temperature measuring instrument equipped with.

[Conventional technology]

This kind of electronic measuring instrument has been adopted in many fields in recent years, and in particular, it is rapidly becoming popular for household use in place of the conventional mercury thermometer because of its simple use.

However, since it does not have the function of recognizing the previous temperature measurement result prior to the temperature measurement operation like the mercury thermometer, it is necessary to make a note of the previous temperature measurement value for each temperature measurement. There was complexity.

In order to solve such a problem, an electronic temperature measuring device has been proposed which has a memory function and holds the temperature measurement result even after the power is turned off so that the temperature measurement result can be read and displayed as needed. : Electronics Digest Co., Ltd., December 10, 1975, "CMOS IC Handbook" No. 287
Pp.-293).

[Problems to be solved by the invention]

In the above-mentioned conventional technique, a dedicated memory switch for reading the temperature measurement result from the memory unit is provided in addition to the switch for starting the temperature measurement, so that the circuit configuration becomes complicated and the entire device is Since the size is increased and the two switches have to be operated separately, the operation is complicated and erroneous, and is not suitable for home use mainly by women and girls.

[Means for solving problems]

The present invention has been made in view of the above circumstances, and includes a switch that can be operated from the outside, a counter that starts counting in conjunction with the first operation of the switch, and a first count value of the counter. Generate a reset release signal,
A signal generation unit that generates a reset signal having a predetermined pulse width with a second count value that is larger than the first count value, a temperature measurement unit that starts temperature measurement by the reset release signal, and a reset signal after reset by the reset signal. , A storage unit that updates the measured temperature data according to a determination signal output from the temperature measurement unit when the measured temperature data of the temperature measurement unit is higher than the stored temperature data, and the first operation of the switch And a display unit that displays the temperature indicated by the temperature data stored in the storage unit, and the counter, the signal generation unit, the temperature measurement unit, and the display unit in association with the second operation of the switch. And a means for bringing the reset state into a reset state, and in conjunction with the operation of the switch, the temperature indicated by the temperature data of the measurement stored in the storage section at that time is displayed on the display section, The reset signal After resetting, the temperature indicated by the temperature data of this time measured by the temperature measuring unit and stored in the storage unit is displayed on the display unit. The miniaturization is realized and the operation is simplified to make 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 a temperature measuring device according to the present invention, in which 1 is a switch, 2 is an oscillator, 3 is a counter, 4 is a NAND gate, 5 is a counter, 6 is an RS type latch circuit, 7 is a counter, 8 is an inverter, 9 is a counter, 10 is a control unit, 11 is a temperature measuring unit, 12 is a storage unit, 13 is a measuring range outside detection unit, 14 is a display decoder, 15 is an indicator, 16 is a NAND gate, 17,18 is RS
Type latch circuit, 19 is a falling edge detector, and 20 to 23 are inverters.

In the figure, an oscillator 2, a counter 3, 5, 7, 9 and a latch circuit 6,
17, 18, the control unit 10, the temperature measuring unit 11, the display decoder 14, and the falling edge detection unit 19 are in the reset state when the signal supplied to the reset terminal R is at a high level (hereinafter referred to as "H"). It is in.

The switch 1 is a normally open switch such as a push button switch that is operated from the outside. When the switch 1 is not operated, one input of the NAND gate 4 is “H”, and the counter 5 and The reset input of the latch circuit 6 is "H" and is reset.

The oscillator 2 is a CR oscillator, a crystal oscillator, or the like, and generates a reference clock MCK. This reference clock MCK is divided into a predetermined frequency by the counter 3 and supplied to the counters 5 and 9 and the display decoder 14. The oscillator 2 and the counter 3 are
The output signal of the NAND gate 4 is inverted by the inverter 8 to be switched between the operating state and the non-operating state by the MCK.N signal.

The counter 5 and the latch circuit 6 form a determination unit for determining that the switch 1 has been operated. In this determination unit, the counter 5 prevents malfunction due to chattering of the switch 1. When the switch 1 is operated and is closed for a predetermined period (about 0.1 seconds) or more, it overflows and its Q output becomes low. Invert from level (hereinafter referred to as "L") to "H". The latch circuit 6 is set at the rising edge of the Q output of the counter 5, and at the same time, its output is inverted from "H" to "L". Counter 5
The latch circuit 6 and the latch circuit 6 are in the reset state when the switch 1 is in the open state, and the reset is released when the switch 1 is in the closed state. Therefore, the output of the latch circuit 6 is output every time the switch 1 is operated to be in the closed state. Invert from “H” to “L”.

The counter 7 is a 1-bit binary counter, which counts one at the falling edge of the output of the latch circuit 6, and its Q output is inverted each time it counts. Q of counter 7
The output is inverted by the inverter 20 and supplied to the counter 9, the latch circuits 17 and 18 and the reset terminal R of the display decoder 14 as the GRST1 signal and also to the NAND gate 4. When the GRST1 signal is “H”, these circuits are in the reset state, and the display unit 15 displays a blank display (that is, nothing is displayed). Further, when the GRST1 signal becomes “L”, reset of these circuits is released at the same time, and the display unit 15 displays predetermined data.

The counter 9 further divides the clock from the counter 3. The Ql output with a predetermined frequency division ratio is supplied to the control unit 10, and the temperature measurement unit
Controls the timing of temperature measurement at 11. A Qm output having a frequency division ratio twice that of the Ql output is supplied to the latch circuit 17 as a set input, and a Qn output having a frequency division ratio twice the Qm output is supplied to the latch circuit 18 as a set input. The latch circuit 17 is set at the first rising edge of the Qm output of the counter 9 after the reset is released, and its output is inverted from “H” to “L”. The output of the latch circuit 17 is used as the GRST2 signal in the control unit 10,
It is supplied to the respective reset terminals R of the temperature measuring unit 11 and the falling edge detection unit 19, inverted by the inverter 21 and supplied to the NAND gate 16, and further inverted by the inverter 23 and EN of the out-of-measurement range detection unit. It is also supplied to the terminals.
In addition, the latch circuit 18 of the counter 9
Set on the first rising edge of the Qn output, its output reverses from “H” to “L”. This output is supplied to the falling edge detection unit 19 which has already been released from reset, and the MAX.R signal representing the falling edge is formed. This M
The AX.R signal resets the storage unit 12 which is a D-type flip-flop, and erases the previously measured temperature value that has been held so far.

When the temperature measuring unit 11 is released from the reset, the Ql of the counter 9
The temperature is measured once for each output cycle, and the temperature measurement is completed immediately before this Ql output. Then, in synchronization with the rising edge of the Ql output, the current temperature measurement value (measured temperature data) obtained at that time is compared with the temperature measurement value (temperature data) retained and stored in the storage unit 12, and at that time When the obtained measured temperature data is higher than the temperature data, the temperature measurement unit 11 generates the determination signal MAX.Φ, and the measured temperature data is stored in the storage unit 12 in place of the temperature data held so far. Write and update. Therefore, the storage unit 12 holds the maximum temperature measurement value obtained so far after the temperature measurement unit 11 is released from reset.

The temperature measurement value stored in the storage unit 12 is read out and supplied to the display decoder 14 via the measurement range outside unit 13 and
If the temperature measurement value read from the storage unit 12 is outside the predetermined measurement range, the outside-measurement-range detection unit 13 displays the temperature on the display unit 15 in order to display that fact. Instead of a value,
Data representing fixed numerical values, signals, patterns, etc. is output to the display decoder 14.

Here, the predetermined measurement range is 32.0 ° C to 42.0 ° C. Storage unit 12 before being reset by the MAX / R signal
If you want to display the previous temperature measurement value held in
When the temperature is lower than 2.0 ° C, the out-of-measurement range detection unit 13
“2.0 ° C” is displayed, and when it exceeds 42.0 ° C, “42.0
℃ ”is displayed. Also, when displaying the current temperature value held in the storage unit 12 after being reset by the MAX / R signal, if this is less than 32.0 ° C, “LO ° C”, 42.0 ° C
When the temperature exceeds, a symbol such as "HI ℃" or a pattern will be displayed. In this way, in order to display the previous temperature measurement value and the current temperature measurement value outside the predetermined measurement range differently, the measurement range outside detection unit 13 is controlled by the signal obtained by inverting the GRST2 signal by the inverter 23. To be done. The GRST2 signal is "H" during the previous temperature measurement value display period, and is "L" during the current temperature measurement value display period.

The display decoder 14 constitutes a display unit together with the display unit 15, and after the GRST1 signal is set to “L” to be released from the reset state, the display decoder 14 decodes the data from the out-of-measurement range detection unit 13 to display the display unit. Although the above display is performed at 15, the signal is further preset by the DisPR signal of "H" supplied from the inverter 22 to the preset terminal PR, and the display 15 is supplied with a signal for lighting all the segments.

Next, the operation of this embodiment will be described with reference to FIG. 2 showing the operation timing of each part.

The previous temperature measurement value is retained in the storage unit 12 even in the non-use state. When a power source (not shown) is turned on, the indicator 15 is activated. At the same time, the reset of the counter 7 is released, but its Q output is "L" and the GRST1 signal is "H". Therefore, the display decoder 14 is in the reset state, the display 15 is displaying a blank, and
The counter 9 and the latch circuits 17 and 18 are also in the reset state. For this reason, the outputs of the latch circuits 17 and 18 are both "H" and the GRST2 signal is "H". Therefore, the control unit 10, the temperature measuring unit 11,
The falling edge detection unit 19 is also in the reset state. "H" GR
The ST2 signal is inverted by the inverter 21 and supplied to the NAND gate 16, and the "H" output of the latch circuit 18 is also supplied to the NAND gate 16. Therefore, the output of the NAND gate 16 is inverted by the inverter 22 to obtain DisPR. The signal is "L"
Is.

Furthermore, since the input of the NAND gate 4 on the switch 1 side is "H" and the GRST1 signal which is the other input is also "H", the MCKN signal obtained by inverting the output of the NAND gate 4 by the inverter 8 is It is "H", and the oscillator 2 and the counter 3 are in the reset state.

In such a state, when the switch 1 is closed, the reset of the counter 5 and the latch circuit 6 is released, and the input of the NAND gate 4 on the switch 1 side is inverted from "H" to "L". It becomes L "and the oscillator 2 and the counter 3 are also released from reset. Therefore, the oscillator 2
Generates a reference clock MCK, which the counter 3 divides.

The counter 5 counts the clock output by the counter 3, but if the switch 1 is closed for about 0.1 seconds or more,
The counter 5 overflows and its Q output is inverted from "L" to "H". This inversion sets the latch circuit 6, and its output is inverted from "H" to "L". At the falling edge of this output, the counter 7 counts by 1,
Its Q output is inverted from “L” to “H”, and therefore GRST
1 signal is inverted from “H” to “L”.

As a result, the display decoder 14 is released from reset. Then, the previous temperature measurement value Nx ′ is read from the storage unit 12, supplied to the display decoder 14 via the out-of-measurement range detection unit 13, and decoded there to be displayed as “Tx ′ ° C.” on the display unit 15. . In this case, when the previous temperature measurement value Nx 'is out of the predetermined measurement range, the fixed value "32.0 ° C" or "42.0 ° C" is displayed.

When the switch 1 is opened, the counter 5 and the latch circuit 6 are reset again, but since the GRST1 signal is "L", the counter 9 and the latch circuits 17 and 18 are in the reset released state as they are, and The output of NAND gate 4 is "H"
The MCK · N signal is held at “L” and the oscillator 2
And the counter 3 is also working.

When the counter 9 continues to count a predetermined number n, the Ql output is inverted from “L” to “H”, and when the count value is 2n and the count value becomes 2n, the Ql output is changed from “H” to “H”. Inverts to "L" and the Qm output inverts from "L" to "H". The latch circuit 17 is set at the falling edge of the Qm output, and its output, that is, the GRST2 signal is inverted from "H" to "L".

Therefore, the reset of the control unit 10 and the temperature measuring unit 11 is released,
In addition, the signal supplied to the EN terminal of the out-of-measurement range detection unit 13 is inverted from "L" to "H" so that the display of the temperature measurement value outside the previous measurement range is different. Further, the input on the inverter 21 side of the NAND gate 16 becomes "H" and the input on the other latch circuit 18 side is also "H", so the DisPR signal is inverted from "L" to "H", and the display decoder 14 becomes It is preset. As a result,
The display decoder 14 is prohibited from accepting data from the out-of-measurement range detector, and all the segments of the display 15 are turned on.

In this way, by lighting all the segments of the display unit 15, it is possible to confirm that the display decoder 14 and the display unit 15 operate normally before starting the temperature measurement.

When the counter 9 continues to count further and the count value reaches 4n, the Ql output and the Qm output of the counter 9 change from "H" to "L", and the Qn output inverts from "L" to "H". This Qn
The latch circuit 18 is inverted from "H" to "H" by the rise of the output. The falling edge of this output is detected by the falling edge detection unit 19 to form the MAX.R signal, whereby the storage unit 12 is reset. As a result, the previous temperature measurement value Nx 'is erased and the value 0 is held in the storage unit 12.

Further, since the output of the latch circuit 18 becomes "L", the output of the NAND gate 16 becomes "H", and therefore,
The DisPR signal becomes “L”, and the display decoder 14 is released from the preset. As a result, the display decoder 14 has a storage unit.
The temperature measurement value read from 12 is supplied via the out-of-measurement range detection unit 13, but in this case, this temperature-measurement value is 0 and out of the measurement range, that is, below 32.0 ° C. The detector 13 displays the data representing "LO ° C" Decoder 14
, And is therefore displayed on the display 15.

When the count value of the counter 9 reaches 5n, the Ql output is inverted from "L" to "H", and the control unit 10 detects this inversion and sends a signal to the temperature measuring unit 11.

On the other hand, in the temperature measuring unit 11, the first temperature measurement is completed immediately before the rising edge of the Ql output of the counter 9, and the control unit 10
When the signal is received from, the temperature measurement value is read from the storage unit 12 and compared with the current temperature measurement value N ₁ . In this case, since the read temperature measurement value is 0, the current temperature measurement value N ₁ is larger. Therefore, the temperature measurement unit 11 sends the determination signal MAX · Φ to the storage unit 12, and the current temperature measurement value N ₁ is sent. Write N ₁ to the storage unit 12. As a result, the display value "T ₁ ° C" for the measured temperature value N ₁ is displayed on the display unit 15.

In addition, the period in which the counter 9 counts by n is set to about 0.7 second here, and therefore the Ql output is about
The cycle is 1.4 seconds, the Qm output is about 2.8 seconds, and the Qn output is about 5.6 seconds. Therefore, the display period of the previous temperature measurement value Tx ′ and the lighting period of all segments of the display unit 15 are about 1.4 seconds each,
It is about 0.7 seconds in the period when "LO ℃" is displayed.

When the counter 9 continues to count and the count value becomes 6n, the Ql output is inverted from "H" to "L", and when the count value is 7n, the Ql output is inverted from "L" to "H". To do. Along with this, in the temperature measuring unit 11, the current temperature measured value N ₂ obtained immediately before that is compared with the temperature measured value N ₁ held in the storage unit 12, and the current temperature measured value N ₂ is large. Sometimes, the storage unit 12 rewrites the current temperature value N ₂ . Therefore, the display value "T ₂ ° C" for the measured temperature value N ₂ is displayed on the display unit 15.

In this way, unless the switch 1 is operated, the counter 9 continues counting, and the current temperature measurement value and the temperature measurement value stored in the storage unit 12 at the rising time of the Ql output for every 2n count for about 1.4 seconds. Are compared, and when the current temperature measurement value is larger, the storage unit 12 rewrites the current temperature measurement value. Therefore, the display 15 displays the maximum temperature measured so far, and the displayed value is updated as the temperature rises.

The Qm output of the counter 9 rises every 4n counts, and the Qn output rises every 8n counts, but the latch circuits 17 and 18 are kept in the set state as they are, and the above temperature measuring operation is continued. It

Next, when the switch 1 is closed, the reset of the counter 5 and the latch circuit 6 is released. In this case as well, the MCK.N signal is held at "L", so that the oscillator 2 and the counter 3 are in the operating state. Therefore, the counter 5 counts the clock from the counter 3, and when it overflows after about 0.1 seconds, the latch circuit 6 is set and its output is inverted from "H" to "L". As a result, the Q output of the counter 7 is inverted from "H" to "L", and the GRST1 signal is inverted from "L" to "H". Therefore, the display decoder 14 is reset,
The display 15 displays a blank.

At the same time, the counter 9 and the latch circuits 17 and 18 are reset, and the outputs of the latch circuits 17 and 18 are inverted from "L" to "H" accordingly, so that the control unit 10 and the temperature measuring unit 11
And the falling edge detector 19 is also reset. In this case, since the MAX.R signal is not generated, the storage unit 12 retains the maximum temperature measurement value Nx so far.
This temperature measurement value Nx becomes the previous temperature measurement value for the next temperature measurement.

Furthermore, one input of NAND gate 4, GRST1
The signal is "H", the other input on the switch 1 side is "L" and MCK
The N signal is "L", but when the switch 1 is opened, both inputs of the NAND gate 4 become "H", so that the MCK · N signal becomes "H" and the oscillator 2 and the counter 3 are separated from each other. It becomes inactive. Of course, the counter 5 and the latch circuit 6 are also reset.

In this way, the temperature measurement operation is completed and the system is stopped.

As described above, in this embodiment, by operating the single switch 1, the previous temperature measurement value and the maximum of the current temperature measurement values are switched and displayed. Moreover, it suffices if these switching displays are closed for about 0.1 seconds or more with one operation of the switch, and there will be no erroneous operation. Therefore, when used for home use, even women and women can easily handle it.

When the temperature measurement value is out of the measurement range, the previous temperature measurement value and the current temperature measurement value are displayed with different values, symbols, or patterns. And can be clearly distinguished.

Further, before the temperature measurement is started, the storage unit 12 is reset and the stored content becomes 0. As a result, “LO ° C.” is displayed on the display unit 15, and it can be confirmed that the temperature measurement is started. .

Furthermore, it is possible to confirm that the display decoder 14 and the display 15 operate normally by turning on all the segments of the display 15 before starting the temperature measurement.

It should be noted that although specific numerical values are shown in the description of the above-mentioned embodiments, these are merely examples and the present invention is not limited to these values.

If the switch 1 can be opened and closed from the outside,
It is possible to use various types such as a push button type, a slide type, or a reed switch provided in a main body case (shown in the figure) and operated from the outside by a spout or the like.

〔The invention's effect〕

As described above, according to the present invention, the switching display between the previous temperature measurement value and the current temperature measurement value and the start and stop of the temperature measurement operation can be performed by operating a single switch.
Moreover, since the switch display between the previous temperature measurement value and the current temperature measurement value and the temperature measurement operation are performed by one operation of the switch, the operation is extremely simplified and the handling becomes extremely easy. It is possible to obtain an excellent effect that the structure is simple and the size can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a temperature measuring device according to the present invention, and FIG. 2 is a timing chart for explaining the operation of FIG. 1 ... Switch, 5 ... Counter, 6 ... Latch circuit,
9 ... Counter, 10 ... Control unit, 11 ... Temperature measuring unit, 12 ...
Storage unit, 15 …… Display unit, 17,18 …… Latch circuit, 19 ……
Falling edge detector.

Front Page Continuation Board of Referees Judge Chief Akio Miyamoto Judge Judge Shida Shinobu Judge Masaru Watanabe (56) References JP 56-158640 (JP, A) JP 48-70575 (JP, A) Showa 55-55726 (JP, U) Showa 39-26924 (JP, Y1)

Claims (1)

[Claims] 1. A switch that can be operated from the outside, a counter that starts counting in cooperation with the first operation of the switch, and a reset release signal generated from a first count value of the counter, A signal generation unit that generates a reset signal having a predetermined pulse width with a second count value that is larger than the count value; a temperature measurement unit that starts temperature measurement by the reset release signal; When the measured temperature data of the temperature measuring unit is higher than the measured temperature data, the storage unit that updates the measured temperature data by the determination signal output from the temperature measuring unit, and the storage unit that operates in conjunction with the first operation of the switch A display unit that displays the temperature indicated by the temperature data stored in the storage unit, and the counter, the signal generation unit, the temperature measurement unit, and the display unit, in conjunction with the second operation of the switch. And a means for putting it in a reset state, and in conjunction with the operation of the switch, the temperature indicated by the temperature data of the measurement stored in the storage section at that time is displayed on the display section, and the temperature of the storage section is displayed. A temperature measuring device characterized in that, after reset by a reset signal, the temperature indicated by the temperature data of the present measurement measured by the temperature measuring unit and stored in the storage unit is displayed on the display unit.