JPH0642174B2 - Temperature display device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature display device used for temperature control devices such as heating appliances and the like.

2. Description of the Related Art Generally, a temperature setting unit and a temperature detection unit are always provided in all devices that set a temperature and control the temperature, but the detected temperature is not always displayed.
In addition, when both the set temperature and the detected temperature are displayed, the two displays are used to display each of them individually or only one of them is selectively displayed.

For example, as shown in FIG. 5, a conventional temperature display device has a temperature detection unit 110 in which a temperature detecting thermistor 101 is divided by an appropriate resistor, and a variable resistor 103 has an appropriate resistor 104 for voltage limiting at one end thereof. To the other end of the temperature setting unit 111, which is also connected to a suitable resistor 105 for voltage limitation,
The signal from the temperature detecting unit 110 is connected to the contact 106-a, and the signal from the temperature setting unit 111 is connected to the contact 106-b, and the switch 106 having a common terminal as an output and the voltage at the common terminal of the switch 106 are input. And an A / D converter 112 for converting an analog voltage into a digital quantity, and
The switch 1 in which the output of the conversion unit 112 is connected to the common terminal
07 and the contact 107-a of the switch 107, which displays the detected temperature in two-digit day-shaped numbers, and the contact 107-b of the switch 107, which displays the set value, also displays the set value. The display unit 113 is composed of a display device 109 for the letter numbers.

The operation of the above configuration is such that when the switch 106 is on the 106-a contact side, the switch 107 is also connected to the 107-a contact side, and when the switch 106 is on the 106-b contact side, the switch 107.
Also, the switch 106 and the switch 107 are interlocked so that they are also connected to the 107-b contact side. That is, the A / D converter 112 alternately takes in the voltage V1 corresponding to the detected temperature and the voltage V2 corresponding to the set temperature by the switch 106 at high speed, and alternately takes in the voltage V1 and converts it into a digital amount at the same time via the switch 7 synchronized with the switch 106. The detected temperature is output to the display unit 108, and the set temperature is output to the display unit 109 to display both the detected temperature and the set temperature.

Further, as another conventional example, when displaying both the detected temperature and the set temperature on one display, the switch 1 in FIG. 6 is used.
It was realized by switching 14 manually rather than automatically.

Problems to be Solved by the Invention However, in the conventional configuration, two display units for the detected temperature and the set temperature are used to display the temperature of the same content even if the detected temperature and the set temperature are different. It's wasteful to do, and the cost is high. Further, it is preferred that the display design adopted in recent consumer devices is simple, and even from this point, the two display devices give a feeling of complexity and require a large space for arrangement. there were.

Furthermore, it is inconvenient for one display to know only one of the set temperatures, and it is more troublesome and practical to switch manually. There is also a risk of misjudgment if it is left to the user to judge whether the current display is the detected temperature or the set temperature in the state of the switch.

An object of the present invention is to solve such a conventional problem, and to display both the detected temperature and the set temperature on one display and to automatically switch the display by judging the status of the setting operation. It was done.

Means for Solving the Problems In order to achieve the above object, a temperature display device of the present invention includes a first display unit that displays a detected temperature and a set temperature, and a display switching unit that switches the content output to the first display unit. And a timer that is initially changed and starts a counting operation each time a temperature setting operation is performed. When the timer counts a predetermined value, the display content of the first display is switched.

Action The present invention has the above-described configuration, and since both the detected temperature and the set temperature are displayed on one display, the cost is low and a simple display design is possible. Moreover, the detected temperature is usually displayed, and when the temperature setting operation is performed, the set temperature is displayed, and the temperature is automatically returned to the original detection temperature if the temperature setting operation is not performed for a certain time. As a result, usability is significantly improved.

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

In FIG. 1, 1 is a thermistor for temperature detection, and 2 is its voltage dividing resistor. Reference numeral 4 is a temperature setting volume, which is appropriately divided by resistors 3 and 5. Reference numerals 6 and 7 are A / D converters for converting an input analog voltage into a digital amount and outputting the digital amount. The A / D converter 6 converts the voltage at the connection point between the thermistor 2 that outputs a temperature signal and the resistor 2 into a digital value, and outputs it to the signal line e as detected temperature information. A /
The D converter 7 receives the voltage of the movable terminal of the temperature setting volume 3 as an input and outputs the result of conversion into a digital amount to the signal line f as set temperature information. On the other hand, the voltage of the movable terminal of the volume 3 is also input to the differentiating circuit 8. The differentiating circuit 8 detects the change of the input voltage, that is, the operation of the volume 3, and outputs the "L" signal while the input voltage is changing. 9, the output signal c of the differentiating circuit 8 is input,
In addition, it is an increment type timer using the oscillator 10 as a clock source, and stops when the count value reaches the highest position. When the output signal c becomes "L", the count value returns to 0, and when the output signal c becomes "H", counting is started. Reference numeral 11 denotes a comparator, which outputs the result of comparing the output of the timer 9 and the value of the fixed value setting device 12.
For example, assuming that the value of the fixed value setting device 12 is set to 3 seconds now, if the output value of the timer 9 is less than 3 seconds, the "L" signal is output, and if it is 3 seconds or more, "H". Output a signal. 13 is a signal line connected to the output signal line d,
The display switch is connected to the signal line e or the signal line f. The display switching unit 13 is an input signal for the comparator 1.
When the output signal of 1 is "L", the signal line f and the signal line d are connected, and when the output signal of 1 is "H", the signal line e and the signal line d are connected. Reference numeral 14 is a two-digit number display represented by day-shaped numbers, and 15 is a detection temperature indicator 1 composed of an LED.
The display content indicator includes 5a and a set temperature indicator 15b. The LED block 15 indicates the detected temperature when the detection temperature indicator 15a is turned on, and indicates the set temperature when the set temperature indicator 15b is turned on. Reference numeral 16a denotes a first driver of the number display unit 14, which constitutes the first display unit 16 together with the number display unit 14 and includes a decoder for converting a digital signal into a corresponding LED lighting pattern. Reference numeral 17a denotes a second driver of the display content indicator 15, which turns on the detected temperature indicator 15a when the output signal of the comparator 11 is "H", and sets the temperature indicator 15b when "L". And the display content indicator 15 constitutes the second indicator 17.

Next, the operation of the above configuration will be described with reference to the timing chart of FIG. Now, assume that the temperature detected by the thermistor 1 is 20 ° C., the set temperature is 18 ° C., the numeral display 14 indicates “20”, and the detected temperature indicator 15a is lit. When the volume 4 is operated to change the set temperature from 18 ° C. to 22 ° C., the change in the voltage V1 is captured and the output signal c of the differentiating circuit 8 becomes “L” (point A). As a result, the timer 9 is initialized and the count value is smaller than the value (3 seconds) of the fixed value setting unit 12, so it is set to zero. As a result, the comparator 11 outputs "L", so that the display switch 13 connects the signal line d to the signal line f. Therefore, the number indicator 14 is "1.
Display contents indicator 15 at the same time as displaying "8" to "22"
The lighting of the number changes from 15a to 15b to indicate that the temperature is the set temperature. When the operation of the volume 3 is stopped when the set temperature is set to 22 ° C., the output signal c of the differentiation circuit 8
Returns to "H", and the counting operation of the timer 9 proceeds from this point (point B). When the count value of the timer 9 becomes 3 seconds or more, the output of the comparator 11 changes from "L" to "H".
Then, the signal line d is connected to the signal line e. Therefore, the number indicator 14 displays the detected temperature of "20", and at the same time, the lighting of the display content indicator 15 changes from 15b to 15a to indicate the detected temperature (point C). When the setting of the volume 3 is continuously changed without stopping for 3 seconds or more like the point E, the output of the comparator 11 continues to be "L".

In the above embodiment, the volume 3 is used as the temperature setting device, but as another embodiment, two non-locking switches 18a and 18b for setting the increasing method and the decreasing direction may be used as shown in FIG. In this case, the change of the set temperature is detected by the detection circuit 19 which is composed of a monostable flip-flop that operates by an edge signal. The counter 23 is a counter that increases or decreases each time the switches 18a and 18b are pressed, and the value indicates the set temperature. Further, FIG. 4 shows the value of the fixed value setting device 12 in the embodiment of FIG.
The variable range is limited to 2 to 5 seconds by the resistor 21 and the resistor 22 in another embodiment in which the variable range is 0.
If the value of the fixed value setter 12 is less than 2 seconds, it will return to the detected temperature display soon after checking the changed set value, and it will be very difficult to see. When trying to express two kinds of contents with one display, the timing of the response subtly affects the usability and is very important, and at the same time individual differences occur. This limit value has a lower limit of 2 seconds and an upper limit of 5 seconds. An A / D converter 23 converts the voltage obtained by the volume 20 into a digital value and sets it in the fixed value setting device 12.

All of these configurations can be performed by the microcomputer 24 and can be easily realized by a program.

EFFECTS OF THE INVENTION As described above, according to the temperature display device of the present invention, both the detected temperature and the set temperature are displayed on one display, and the configuration can be simplified. Also, since the count of the timer is initialized at every setting operation, the set temperature is displayed during the setting operation,
After a certain confirmation period after the operation is completed, the original detected temperature is displayed and the usability is significantly improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a temperature display device of the present invention, FIG. 2 is a waveform diagram of each part of the device, and FIGS. 3 and 4 are block diagrams showing another embodiment of the same. 5 and 6 are block diagrams showing a conventional example. 1 ... Thermistor for temperature detection (temperature detection means), 3 ...
... Volume for setting temperature (temperature setting means), 6 and 7 ... A / D converter, 8 ... Differentiating circuit, 9 ... Timer, 11 ... Comparator, 13 ... Display switching unit, 16 ... First indicator.

Claims (3)

[Claims] 1. A temperature detecting means for detecting a temperature, a temperature setting means for setting an arbitrary temperature, a first display for displaying the detected and set temperature by a numeral, and each time the temperature setting means is operated. , A timer that is initialized and starts counting, and normally outputs the temperature detected by the temperature detecting means to the first display, and outputs the output content until the timer counts a predetermined value after the temperature setting means is operated. A temperature display device comprising: a display switching means for changing to a set temperature and outputting it to the first display. 2. A comparator is provided for comparing the value of the timer with a predetermined value and sending the output to the display switching means, and the predetermined value to be compared with the value of the timer can be varied by this comparator. The temperature display device according to claim 1. 3. The temperature display device according to claim 2, wherein the variable width of the predetermined value to be compared with the timer value by the comparator is limited to 2 seconds to 5 seconds.