JPS5917770B2 - electronic thermometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic thermometer, and more particularly to an electronic thermometer that digitally displays the output of a temperature sensing element within a temperature measurement range.

The output of a temperature sensing element is generally exactly proportional to temperature within a certain range of temperature, but not exactly proportional to temperature outside the certain range.

Therefore, in a device that digitally displays the output of a temperature sensing element, if the output of the temperature sensing element is directly displayed when the temperature is outside a certain range, the displayed value will be inaccurate. However, if there is no display at all when the temperature is outside a certain range, it will be impossible to tell whether the electronic thermometer is working or not. This invention was made in consideration of the above problems, and its purpose is to provide an electronic thermometer that digitally displays the output of a thermosensor and that notifies you when the temperature is outside the temperature measurement range. The goal is to provide the following.

Another object of this invention is to
'' is displayed, and when the temperature is below the temperature measurement range, ``L'' is displayed.

In order to achieve the above object, the present invention includes a detection part that detects that the output of the temperature sensing element is outside the temperature measurement range, and a notification part that notifies that the output of the detection part is outside the temperature measurement range. establish.

In addition, the temperature measurement unit detects temperatures above and below the temperature measurement range,
The alarm unit will output H'' when the temperature measurement unit detects a temperature above the temperature measurement range.
is displayed, and when the temperature is detected to be below the temperature measurement range, L'' is displayed.

Next, before describing the embodiment, an overview will be given based on a functional block diagram (Figure □) and a schematic flowchart (Figure 8).

The output of the temperature sensing element 110 is converted into numerical data by an AD conversion means 111.

112 is an adder that adds the numerical data from the AD conversion means 111 and a basic value (equivalent to 300 V in the embodiment described later).

A maximum value holding circuit 113 holds the maximum value of the addition results.

Reference numeral 114 denotes a display control means, which displays the maximum value obtained sequentially as described above, and switches between displaying "L" or "H".

Reference numeral 115 denotes a comparison means, which determines whether the numerical data of the AD conversion means 111 is within a predetermined range (a range in which temperature measurement is possible) or not, if the numerical value is equal to or greater than the lower limit (“20” in the example described later) and the upper limit (“20” in the example described later). 130), and if the result is below the lower limit, display 3゛L゛ (S4, S5 in Fig. 8).
), if it is above the upper limit, “H” is displayed (S6 in Fig. 8,
S7) Control the display control means 114 to display.

On the other hand, within the above range, SlO, SlI, Sl2
, Sl3, the maximum value obtained one after another, that is, the measured body temperature, is displayed on the display 116. Embodiments illustrating the present invention will be described in detail below.

In this embodiment, a microprocessor is used, and the temperature measuring section is operated by the microprocessor.
FIG. 1 shows a bridge circuit for taking out the output of the temperature sensing element, a circuit for charging and discharging by the output of the temperature sensing element, that is, the output of the bridge circuit, and an interrupt circuit according to the present invention.
FIG. 2 is an electrical connection diagram showing the configuration of an embodiment.

In FIG. 1, reference numeral 1 denotes a pritzge consisting of a temperature sensing element 2 and resistors 3, 4, and 5, and a power supply 6 is connected to the input terminals 7 and 8 of the pritsge 1.
connected to. Reference numeral 11 designates an operational amplifier, the input side of which is connected to the output terminals 9 and 10 VC of the bridge 1.

A capacitor 12 is connected between the output terminal 9 and the output terminal of the amplifier 11.

The positive side of capacitor 12 is connected to microprocessor 14 via resistor 13. Reference numeral 15 denotes a zero point detection transistor, whose base is connected to the negative side of the capacitor 12, its emitter is grounded, and its collector is connected to the power supply 16 via a resistor 17, and the microprocessor 1
Connected to 4.

15, 16, and 17 constitute an interrupt circuit that outputs an interrupt signal.

Next, the operation of the device shown in FIG. 1 will be explained.

The temperature sensing element 2 receives body temperature, and its resistance value changes according to the temperature. Until the temperature of the temperature sensing element 2 exceeds 30°C, the polarity of the output voltage at the output terminals 9 and 10 of the bridge 1 is opposite to the charging polarity of the capacitor 12, and due to the presence of the operational amplifier 11, 12 charging is not performed. When the temperature of the temperature sensing element 2 exceeds 30° C., the polarity of the output voltage at the output terminals 9 and 10 of the bridge 1 becomes a predetermined polarity, and the capacitor 12 is charged. For this purpose, the bridge 1 should be in equilibrium when the temperature of the temperature sensing element 2 is 30°C. Microprocessor 14
As will be described later, the built-in count register CR counts 200, and every time it counts 200, the temperature sensing element 2
It is checked whether the temperature of the capacitor 12 is 30° C. or higher, that is, whether the capacitor 12 is charged. The operation for counting 200 will be described later.

If the temperature exceeds 30° C. at this time, the microprocessor 14 issues a discharge command to discharge the charge in the capacitor 12 via the resistor 13. A discharge MOS transistor (not shown) is built into the microprocessor 14, and the MOS transistor becomes conductive in response to a discharge command, and the charge in the capacitor 12 is discharged through the resistor 13 and the MOS transistor. When the charged potential of the capacitor 12 drops to a predetermined value (zero potential in this embodiment) due to discharging, the transistor 15 generates a signal, which is applied to the microprocessor 14 as an interrupt signal. When the interrupt signal is applied ≧, the microprocessor 14 makes the MOS transistor non-conductive and the capacitor 12VC. Start charging again. When the discharge ends, the count register CR
This is before the count value reaches 200. The counting operation or counting speed of the count register CR will be explained with reference to FIG. In FIG. 2, from time TO to t1, from t1 to T
2, each count register CR counts 200, and each time it reaches 200, the microprocessor 14
checks whether the capacitor 12 is charged or not. If capacitor 12 is charged at time T2, microprocessor 14 causes charging/discharging circuits (11, 12, 13 and MOS transistors in FIG. 1) to discharge. The capacitor 12 is charged by an output voltage of a predetermined polarity between the output terminals 9 and 10 that is generated when the temperature of the temperature sensing element 2 exceeds 30°C. It is proportional to the value where the temperature of No. 2 exceeds 30°C. For example, if the temperature of temperature sensing element 2 is 36.5°C, then temperature 6
．． The unbalanced voltage of the bridge 1 caused by the 5° C. earth rise becomes the charging voltage of the capacitor 12. By appropriately determining the resistance values of the resistor 13 and the MOS transistor, it is possible to maintain the voltage from time T2 to time T3 in FIG. The count value of the count register CR can be set to be 65. In this case, the count value from the start of discharge to the end of discharge is 65, and the charging potential of capacitor 12 is due to the fact that the temperature of temperature sensing element 2 exceeds the temperature of 30 °C when bridge 1 is in equilibrium by 6.5 °C. This is the output voltage of the bridge 1 that occurs. Therefore, if the temperature of the temperature sensing element 2 is, for example, 35.degree. C., the count register CR will count 50 corresponding to a temperature of 5.degree. C. from the start to the end of discharge. Assuming that discharging ends at time T3 in FIG. 2, the microprocessor 14 causes the charging/discharging circuit to start charging again, and also issues an interrupt command to count equivalent to counting 100 using the count register CR. It is processed by

After the interrupt command is executed, the microprocessor 14 instructs the count register CR to continue counting. By the time an interrupt signal is generated, the count register CR counts 65 when the temperature is 36.5°C, so it is 20.
Count 0-65=135. The time T when this counting ends
4, the count value 200 of the count register CR and the interrupt instruction (by executing the interrupt instruction, the count value 200 of the count register CR
Steps equivalent to counting 100 in R are consumed. ) is 300. At time T4, the microprocessor 14 checks whether or not the capacitor 12 is charged;
If it is charged, it commands discharge and repeats this operation an appropriate number of times. During this time, the temperature of the temperature sensing element 2 is assumed to reach the same temperature as the body temperature to be measured. Until then, as shown at times T4, t6, and t8vc in FIG. 2, each time the total count value reaches 300, the sum of this value 300 and the count value of the count register CR until the end of discharge is calculated. The numerical value 300 is a value corresponding to a temperature of 30°C. For example, if the temperature of the temperature sensing element 2 is 36.5°C at time T2, the count register CR up to time T3
The count value is 65, and the value 300 is added to this, which is 36.
5 is converted into temperature to obtain 36.5°C. Until the temperature of the thermosensor 2 becomes the same as the body temperature, for example, at time T.
5} is the count value of the count register CR at time T3l.
The count value of the count register CR remains constant after reaching the same temperature as the octabody temperature, which becomes larger than the lc count.

Therefore, the total value of 300 and the count value from the start of discharge to the end of the resistor CR is memorized each time, and the current total value is compared with the previous total value, and the current total value is the previous total value. If it had not become larger than the value, the temperature sensing element 2 has already
It is assumed that the temperature has become the same as the body temperature, and the total value at this time is converted to temperature and displayed on the display.

Next, the above operation will be explained using a flowchart.

First, the arrangement of the microprocessor will be explained with reference to FIG.

21 is a microprocessor, F, T, A, and B are registers, IR is an instruction register, ALU is a logic operation circuit, PC is a program counter, and +l is a +1 circuit.

Next, the layout of the RAM will be explained with reference to FIG.

In Figure 4, BR on the horizontal axis (O to 9, A to F)
The RAM address can be specified using MR (0 to 7) on the vertical axis. The BR on the horizontal axis is specified by the B register, and the vertical axis is specified by the program. In FIG. 4, CT and LC are counters, XR is a display register, CR is a count register, DR is a data register, and T, A, and B are registers. Figures 5-1 and 5-2 are flowcharts, and the numerals 1, 2, . Simply repeat each step 1, 2,...
Indicated by 0.

However, there are missing numbers. First, reset the RAM in step 1, then
20 from the microprocessor to the count register CR.
Give the command to count 0.

Every time the count register CR counts 200, the contents (data) of the counter CT are incremented by 1 by 3. Counter C at 4
Check whether the T data has changed to 1611C.

If NO, check whether the temperature is below 30℃ with 5, then press YE.
If it is S (below 30°C), register F2 is set at 6, and it is therefore determined whether the temperature has been displayed before. As will be seen later, when the temperature is below 30°C, except for cases where the temperature is once above 30°C and then becomes below 30°C, for example, at time tl in Figure 2, DR < 5XR. are both zero. Then return to 2 and counter C
T is incremented by 1 and the process moves from 4 to 5 until the data on the counter CT reaches 16VC. For example, in this case, time T in Figure 2
2, the temperature of the temperature sensing element 2 has reached 30°C. Therefore, when checking whether the temperature is <30℃ at 5, it is N.
It becomes OVC. Therefore, reset the register F2 with [phase], give a discharge command from the microprocessor to the charging circuit in (b), and set INTE to ``1'' with @.I
By setting "1" in NTE, interrupts are enabled.At this time, count register CR is set to 2.
Counting by VC continues, but when the charge/discharge circuit discharges to a predetermined value, that is, to zero potential in this embodiment, an interrupt signal is generated from the zero potential detection transistor 15 in FIG. INT) joins the microprocessor, moves to step 0VC, and CR at 2.
Counting is stopped at that point. This point corresponds to, for example, T3 in FIG. At ◎, a charging command is issued to the charging/discharging circuit, and the capacitor 12 in FIG. 1 starts charging again.
Step 9 moves the data in registers A, F, and B to RAM, and moves the contents of count register CR to data register D with @.
Put it in R.

For example, the count register C at time T3 in FIG.
If the count value of R is 65, this count value 65 is entered into the data register DRVC. Data register DR with O
Correct the contents of. This is because when the interrupt signal 1NT is applied, if the count value of CR changes from 19 to 20, for example, the lowest 9 changes to O, and the second
When the digit 1 has not yet changed to 2, the contents of the count register CR are transferred to the data register DR, and the contents of DR become 10. This is because the content of DR must be corrected to 20 at this time. After correcting the contents of DR in [phase], reset register F2 in step 5, and reset the counter LC in [phase].
Add +1 to This is because the operation of discharging and charging the charging/discharging circuit is repeated 15 times, so the number of charging/discharging operations can be calculated using the counter LC. O(' Check whether LC = 15 or not, and if NO, make sure that the same number of steps is consumed as when going through the YES routine in [phase]. This is done after moving to the interrupt instruction. This is because the number of steps equivalent to counting 100 in the count register CR is consumed no matter which routine is passed until exiting from the embedded instruction.F2 is set with O, and @, @: The number of steps can be calculated using 0, 0. A predetermined number of steps is consumed for the same purpose as in the case of [phase].

The data that was transferred to RAM with @ is transferred to registers A, F, BV.
Read C and return to 2 with [phase]. 2, the count register CR receives the interrupt signal 1NTVC. Then restart the counting that had been interrupted.

For example, if 65 were counted at the time of interruption, the remaining 135 are counted until the count reaches 200, and when the count reaches 200, the process moves to 3 and the contents of CT are incremented by 1. After time T2 in Figure 2, the operations from 2 to 5 and from [phase] to [phase] are repeated, and when this operation is repeated 15 times, LC = 15 at [phase], so @ is YES.
and moves to @. Check whether DR≧20 in [Phase]. However, in this example, the temperature is below 32°C and 43°C.
If the temperature exceeds ℃, the measurement will be inaccurate, and therefore the value below or above the measurement range will be indicated. DR≧20
If so, use @゜ to check whether DR≦130. Y
If it is ES, add DRVC3OO in [phase] and add XR in @
Check whether it is ≧DR. As will be described later, the data in the data register DR is stored in the register XR, and currently the previous data in the register DR is stored in the register XR. When LC=15VC is reached for the first time, the data of register DR has not yet been stored in register XR, so @ becomes NO. Therefore, moving to [phase], data register DR
The contents of register XRVC. Enter it, use @ to consume the specified step, and move to 2 via [phase] and [phase]. After the count value reaches 15 VC, the naori counter LC is reset to @, which will be described later, and starts counting from 1. The above operations, i.e. 2 to 5, [phase] to @, [phase] to [phase]
, @. While repeating the operations in the order from to @, the temperature of the temperature sensing element 2 becomes the same as the body temperature to be measured. After that [
phase]. DR≧20 is YES ('Yes, @ is DR≦13
If 0 is YES, then XR=DR in [phase], so O
Display the temperature at that time. This is [phase] and DRr
The value obtained by adding c3OO is converted to temperature and displayed. In this example, the value calculated in [phase]: is converted to 10
The value divided by is displayed as temperature. : @ DR≧20
If NO, check whether the temperature was displayed in step 4.

If the temperature has already been displayed with O, temporarily press D.
After R≧20VC and XR=DR (or The maximum temperature measured on the display remains displayed.
When we found out in step 9 that the temperature was not displayed, the temperature of the thermosensor 2 had not yet reached the human body temperature.
It is conceivable that the temperature will rise further (however, the temperature to be measured may be 32° C. or lower).

) Move to 9, set F2, and return to 2 via :0, 0, [present], [phase]. O'('Check whether DR≦130. If NO, it means that the temperature of the thermosensor 2 has already exceeded 43℃, which is beyond the accurate measurement range, so turn O immediately. Instruct the display of ゛H” on the display with O.
Display.

This "H" indicates that the temperature to be measured is higher than the measurement range and therefore cannot be measured accurately with this device.Since it was NO in [phase] and NO in @,
If it returns to 1 after going through Yunaishi@, check whether CT=16 at 4, and if NO, check at 5 whether the temperature is 30℃, and if NO, repeat the operation below [phase], YES
If so, set F2 at 6, check whether the temperature has already been displayed, and if the temperature has not been displayed by then, the temperature of temperature sensing element 2 is still rising, so return to 2, and then If the temperature has been displayed before, it means that the temperature of the temperature sensing element 2 has dropped from the previous measurement value because it was removed from the human body, so press O to display the highest temperature up to that point. In addition, if CT=16VC in 4 during the above operation, O
Then, the counter CT is reset and it is checked whether F2=1 at 0. At this time, if the temperature is below 30°C, or if it is below 30°C after the temperature has been displayed, or if the LC has not yet counted 15, F2 is set at 6 or (b). Since F2=1, a command to display "L" 5 is issued at O, and the display is caused to display "L" at 9. Then counter C at 7
T is +1, and when CT reaches 576 (assuming that 1 second has passed during this period), the data in register DR is put into register XR at 0, and O('LC register is reset,
Reset the counter CT with ◎ and return to step 2. If F2 is not set at 0, give a command to display the temperature of the data stored in the display register XR at 5 at 0.
The routine moves to routine 9,0,0 for displaying seconds.

As is clear from the above explanation, in this embodiment, while the temperature is in the process of rising after the start of measurement, "L" is displayed for 1 second until the temperature exceeds 30°C, and in step 4, The time it takes for the CT to count 16 (in this example, it is 1.5 seconds).

) does not display any data, but once the temperature exceeds 30°C, it displays the temperature for 1 second, and then displays the next VCl. The blinking display is performed by giving a blank time of 5 seconds with no display. Furthermore, if the temperature exceeds 32°C and then falls below 32°C, or if it exceeds 43°C, the highest temperature measured during the measurement period (this is the register XRVC
Are you included? ) In other words, H"" is displayed continuously. FIG. 6 is a front view of the electronic thermometer, where 100 is the electronic thermometer and 101 is a display section. In Figure 6, number 3
6.5 (This indicates the temperature), but if the temperature is within the temperature measurement range, the temperature measured at that time will be displayed. If the temperature is above the temperature measurement range or below the temperature measurement range, no number is displayed and "H" or "L" is displayed in the 102 section. According to the present invention, in the range where temperature measurement cannot be performed accurately, inaccurate numerical values are not displayed to confuse users, and the two marks indicate that the thermometer itself is operating normally. Therefore, it is possible to obtain an electronic thermometer that is very easy for the user to handle.

In addition, generally, body temperature can be used as long as it is accurate to several degrees Celsius around 37 degrees Celsius, so according to the present invention, it is possible to use an element with a relatively narrow range as a temperature sensing element. Accordingly, by using inexpensive elements, the cost of the thermometer itself can be reduced, and its practical effects are significant.

[Brief explanation of drawings]

Fig. 1 is an electrical connection diagram showing the configuration of one embodiment of the Blitz circuit, charging/discharging circuit, and interrupt circuit for extracting the output of the temperature sensing element in this invention, and Fig. 2 is an explanation of the operating principle of the electronic thermometer. Fig. 3 shows an example of the arrangement of the microprocessor, Fig. 4 shows an example of the arrangement of the RAM, Figs. 5-1 and 5-2 are flow charts, and Fig. 6 shows an example of the arrangement of the RAM.
The figure is a front view of the electronic thermometer, FIG. 7 is a functional block diagram, and FIG. 8 is a schematic flow chart. 1... Bridge circuit, 2... Temperature sensing element, 14... Microprocessor, DR...
data register.

Claims (1)

[Claims] 1. In an electronic thermometer equipped with a temperature sensing element, an A/D conversion means for A/D converting the output of the temperature sensing element, and a display that receives the output of the A/D conversion means and displays the body temperature numerically. , a setting means for setting an upper limit value and a lower limit value of a possible temperature measurement range of the temperature sensing element; and a setting means for setting an upper limit value and a lower limit value of a temperature measurement possible range of the temperature sensing element; a comparison means for specifically detecting whether the temperature is above the above-mentioned lower limit value or below the above-mentioned lower limit value; and a second mark different from the second mark when the output of the temperature sensing element is equal to or less than the lower limit value is displayed on the indicator instead of the numerical display. an electronic thermometer, the electronic thermometer having a control means, the first or second mark indicating that the thermometer is in operation when the temperature is outside the range in which the temperature can be measured.