JPH04110586A - Refrigerator indoor temperature display device - Google Patents

Abstract

PURPOSE:To enable an indoor temperature of a refrigerator to be got in a sensitive manner by a method wherein two-color light emitting diode is controlled in its light emitting operation and a difference between a temperature of a temperature sensor and an indoor set temperature of the refrigerator is displayed in an analogue form as a variation of color-phase. CONSTITUTION:A panel plate 3 having a temperature displaying part 1 where an indoor temperature of refrigerator appears as a variation in color-phase and an operating knob 2 for use in setting an indoor refrigerator temperature is installed. A two-color light emitting diode is disposed at a rear part of the temperature displaying part 1. Numbers 1 to 9 set at an upper part of the operating knob 2 for use in setting the refrigerator indoor temperature which can be slid in a rightward or a leftward direction indicate a refrigerator indoor temperature which can be set. The two-color light emitting diode 10 constitutes a red color light emitting element R between it and one anode A1 disposed in respect to a common cathode K, and two elements having a green light emitting element G is formed between it and the other anode A2 are inserted into a transparent insulating case 11. Electrical current values flowing in each of the light emitting elements R, G are adjusted, a brightness of each of the light emitting elements R and G is varied and the colors of the light emitting diode 10 is changed to red, orange and green, respectively and then a difference between the set temperature in the temperature sensor and the set temperature value is displayed at the temperature displaying part 1 as a variation in color-phase.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an internal temperature display device for refrigerators, refrigerated showcases, etc.

(B) Conventional Technology In recent years, refrigerators, refrigerated showcases, etc. that enable long-term preservation of food by refrigerating or freezing it have become popular, whether for home or commercial use. In these freezing and refrigeration equipment, it is desirable to be able to easily grasp the refrigeration (freezing) temperature of food in order to ensure food preservation management. Therefore,
As a conventional refrigerator temperature display device, Japanese Patent Application Laid-Open No. 55-685
A method as shown in Publication No. 68 has been proposed.

What is described in the bulletin does not directly display the temperature detected by a temperature sensor placed in the freezer or refrigerator compartment, but instead displays a temperature value that is obtained by averaging the fluctuating detected temperatures, which more closely approximates the food temperature. temperature information can be obtained.

In addition, a method has been proposed in which a temperature sensor is added exclusively for temperature display, and a pseudo load is used to display a display that eliminates temperature variations.

(c) Problems to be solved by the invention However, it is difficult to average the temperature detected by the temperature sensor inside the refrigerator.
Alternatively, in the case of a method that eliminates temperature variations and displays the temperature close to the set temperature, the displayed temperature tends to hardly change, making it easier for users to intuitively understand whether the cooling function of a refrigerator, etc. is working smoothly. There is no such thing, so I am left feeling anxious. In particular, even if a failure occurs in the cooling device and the temperature becomes abnormal, the displayed temperature will be averaged or close to the set temperature, resulting in a problem in which failure cannot be immediately determined. In addition, a dedicated temperature sensor is required separately for temperature display, resulting in problems such as an increase in parts cost and a complicated circuit configuration.

The present invention solves the above problems and uses a temperature sensor that is involved in the control of the compressor, and the temperature inside the refrigerator is displayed as an analog value to indicate the difference from the set temperature, so that the temperature inside the refrigerator can be grasped intuitively. It is an object of the present invention to provide a refrigerator temperature display device that can effectively manage temperature.

(d) Means for solving the problem In order to achieve the above object, the present invention detects the temperature inside the refrigerator,
A temperature sensor that outputs detected temperature information based on the detected temperature, a temperature setting means that sets the internal temperature to a desired temperature, a two-color light emitting element having two light emitting parts of different colors, and each light emitting element. The driving current of the parts is adjusted based on the temperature information detected by the temperature sensor, and as the temperature changes from a low temperature range to a high temperature range within a predetermined temperature range including the set temperature, one light emitting part is strengthened and the other light emitting part is strengthened. The device is equipped with a control circuit section that controls light emission to weaken it, and a temperature display section that has the two-color light emitting element on the back side and displays a hue that changes depending on the degree of light emission of both light emitting sections.

Further, when the temperature sensor detects an abnormal state of high or low temperature in which the temperature inside the refrigerator exceeds a predetermined temperature range, the temperature display section displays a display state in which only one of the colors is emitted. It was designed so that

(e) When the internal temperature of the chamber is approximately the set temperature, driving current flows through the two light emitting parts of the 42-color light emitting element, and the temperature display part is displayed in a color intermediate between the two colors. However, as the temperature becomes higher or lower than the set temperature, the drive current flowing through one of the light emitting parts increases, and the hue of one becomes stronger. Thereby, the temperature display unit can recognize the internal temperature situation and the operating status of the cooling device by observing the change in intensity of the corresponding hue. In particular, when the temperature is abnormally high or low, only one color appears, so abnormal temperature situations can be immediately determined.

(f) Example The present invention will be described in detail below with reference to one drawing.

FIG. 1 shows a panel board 3 that includes a temperature display section 1 that displays the internal temperature as it changes in hue, and an operating knob 2 for setting the internal temperature.
This is a partial perspective view of a door body 4 of a refrigerator or the like equipped with a temperature display section 1, and a two-color light emitting diode (LED) is disposed on the back side of a temperature display section 1. The numbers 1 to 9 above the operating knob 2 for setting the internal temperature, which can be slid left and right, indicate the internal temperature (°C) that can be set, and in the figure, the internal temperature is set at scale "5". This shows the case where the temperature inside the refrigerator is set to +5° C. by aligning the center mark 2a of the operating knob 2. When the operation knob 2 for setting the temperature inside the refrigerator is set to "5" in this way, cooling operation control for controlling the temperature inside the refrigerator at 5° C. is executed.

Specifically, the compressor is turned on at +7℃ and turned on at +3℃.
The temperature is controlled within a temperature range of ±2° C., that is, 4° C., centered around +5° C., by ON/OFF control so that the switch becomes FF. A temperature sensor (described later) that detects the temperature inside the refrigerator and participates in the control is disposed inside the refrigerator.

On the other hand, the two-color light emitting diode IO, as shown in Figure 2,
The red light emitting element part (R) is placed between one anode pole (A) and the common cathode pole (K).
It has a structure in which two elements are inserted into a transparent insulating case part 11, which constitutes a green light emitting element part (G) between it and the other anode pole (A). By adjusting the balance of the current values flowing through each light emitting element part (R, G), both light emitting element parts (R, G) can be adjusted.

G) The same light emitting diode 10 as a whole by changing the brightness of
The color of the temperature sensor is changed to red, orange, and green, so that the difference between the temperature sensor and the set value temperature appears on the temperature display section 1 as a change in hue. That is, specifically, it is as follows.

Red: 2°C higher than the set value (e.g. 5°C) Orange: Set value (5°C)
For example, 5°C) Green: 2 degrees lower than the set value (for example, 5°C) Therefore, when the temperature display section 1 displays a color other than orange, slide the operation knob 2 for setting the internal temperature to set the temperature. When the display section 1 is adjusted to orange, the operation knob 2 for setting the temperature inside the refrigerator will be turned on.
There is also the advantage that the temperature of the temperature sensor can be accurately known from the memory display (1 to 9) of the position where the sensor has stopped.

Next, a specific example circuit of the present invention will be explained. In addition, the set temperature set with the operation knob 2 for setting the internal temperature is 5°C, the upper and lower limit temperatures are 7°C, 3°C, and 4°C.
An example of control in a temperature range of .degree. C. will be explained. Figure 3 is a circuit configuration diagram that includes a compressor control circuit and a two-color light emitting diode disturbance circuit. First, the compressor control circuit (I) will be explained. A thermistor 12 arranged as an element is connected in series with a standard resistor 13, and the standard resistor 13 changes its resistance value depending on the temperature inside the refrigerator. The change in resistance value is extracted as a divided voltage Va with respect to the standard resistance value 13, and is inputted to one terminal of the differential amplification circuit 14. On the other hand, the variable resistor 15 is adjusted by the operation knob 2 for setting the temperature inside the refrigerator, and the set temperature inside the refrigerator is applied as a divided voltage vb to the ten terminals of the differential amplifier circuit 14 via the resistor 16. has been entered.

In this case, the output of the differential amplification circuit 14 is a standard resistance value] 3, the divided voltage Va of the thermistor 12, and the voltage vb set by the operation knob 2 for setting the temperature inside the refrigerator are compared, and the thermistor 12 is When the detected temperature is 2 degrees Celsius higher than the set value temperature, an H output is output, and when it is 2 degrees Celsius lower, an L output is output. In this way, the differential amplifier circuit 14 operates at the set temperature (+
The resistor 16 and the feedback resistor F are designed so that an output change occurs when the temperature is ±2°C with respect to 5°C.

The output of the differential amplifier circuit] 4 is input to the transistor 18,
It controls the operating relay 19 of the compressor. As a result, when the temperature inside the refrigerator becomes high (+7° C. or higher), the H output of the differential amplifier circuit 14 turns on the transistor 18, energizes the operating relay 19, and operates the compressor. When the inside of the refrigerator becomes cold (below +3° C.), the transistor 18 and operation relay 19 are turned off by the L output of the differential amplifier circuit 14, and the operation of the compressor is stopped. By controlling the compressor in this way, the temperature inside the refrigerator is centered around the set temperature (+5°C) @
The temperature is controlled to maintain a temperature within 4°C.

Next, an LED rotation circuit [) that controls the lighting of the red LE020 corresponding to the red light emitting element part (R) and the green LED 21 corresponding to the green light emitting element part (G) shown in FIG. 2 mentioned above.
I will explain about it.

The voltage Va extracted from the connection point between the thermistor 12 and the standard value resistor 13 is treated as a linear voltage change with respect to temperature due to the negative characteristic of the thermistor 12. This Va is input to one terminal of the differential amplifier circuit 22 via a resistor 23,
A divided voltage from the connection point between the resistors 24 and 25 is input to the ten terminal of the differential amplification circuit 22. Here, the differential amplification circuit 22 is configured such that the temperature of the thermistor 12 is the set temperature (5
degree C), the output is adjusted by the resistors 23, 24, 25 and the feedback resistor 26 so that the output becomes a predetermined voltage Va (3V). By the way, the divided voltage vb from the variable resistor 15 is inputted to each one terminal of the differential amplification circuit 27.28 via a resistor 41.42, while each 27.2
The divided voltage from the variable resistor 29.30 is input to the terminal of 8. Further, 43 and 44 are feedback resistances.

Here, the output voltage Vd of the differential amplification circuits 27 and 28.

Ve amplifies the voltage divided by the variable resistor 15 by a factor of 1, so that when the set value of the variable resistor 15 is 5°C, the voltages become the respective predetermined voltages (approximately 2.07 V and 3.29 V). Adjust and set the variable resistors 29 and 30.

Then, the output Vd of the differential amplification circuit 27 and the output Ve of the differential amplification circuit 28 are respectively used as one input via the resistors 31 and 34, and the output Vc of the differential amplification circuit 22 is inputted to each resistor 33, Differential amplification circuits 35 and 36 are provided, which are commonly input to the other side via 32. In the differential amplifier circuit 35, the output Vd is inputted to one terminal, the output Vc is inputted to the tenth terminal,
On the other hand, in the differential amplifier circuit 36, the output Ve is at the + terminal,
Output Vc is input to one terminal. Here, the outputs Vg and Vh of the differential amplification circuits 35 and 36 are the outputs Vc of the differential amplification circuit 22 and the outputs of the differential amplification circuits 27 and 28 ~"d, Ve
, and are multiplied by a predetermined positive number (for example, about +10 times) and a negative number (for example, about -10 times) by differential amplification. (Actually, the output of the differential amplification circuit 22 is the voltage (for example, 31.'
Then, the set value of the variable resistor 15 is set to 5° C., and the outputs of the differential amplifying circuits 35 and 36 are adjusted to a certain voltage (for example, 3.1 yen) using the variable resistors 29 and 30. ) 37.38 is a feedback resistor, and 42.43 is a resistor. By doing this, the outputs vg and vh of the differential amplifier circuits 35 and 36
is the internal temperature (detected temperature of thermistor 2) in the temperature range of 3°C to 7°C, and the voltage value that is converted to voltage Vx”Vy changes in the range of, for example, 1.7v to 4.5v. That's how it goes.

Of course, the outputs of the differential amplifier circuits 35 and 36 have an inverse relationship, so when the output vg is 1.7V, the output vh is 4.5V.
v, and when the output Vg is 4.5v, the output vh is 1.7
It outputs V.

Then, the output voltage Vg of the differential amplification circuit 35 whose output changes from 1.7V to 4.5V is applied to the red LED 20 and adjusts the current value (Ir) flowing through the red LED 20 via the load resistor 39. . Therefore, the red LED 20 indicates that the temperature of the thermistor 12 is -2°C (2°C) lower than the set value (5°C).
When changing from +2°C (lower) to +2°C (2°C higher), the light gradually becomes brighter from almost off. In other words, the higher the temperature, the stronger the red light is emitted. Similarly, the differential amplifier circuit 36
The output voltage vh whose output changes from 1.7V to 4.7V is applied to the green LED 21 and adjusts the current value (Ig) flowing through the green LED 21 via the load resistor 40. Therefore, in this case as well, the green LED 21 gradually turns off from a bright state when the temperature of the thermistor 12 changes from -2°C to +2°C from the set value (5°C). In other words, the lower the temperature, the stronger the green light is emitted. At the set temperature (5° C.), the red LEE 20 and the green LED 21 have equal luminescence intensity, and exhibit an orange color that is a mixture of both. In this way, depending on the temperature detected by the thermistor 12, the differential amplifier circuit 3
5.36 output Vg, Vh changes, red LED20,
The current value flowing to the green LED 21 changes, and the current value flowing to the red LED 2 changes.
0. Due to the balance of light from both green LEDs 21,
The temperature display section 1 of the two-color light emitting diode 10 changes its hue from red to orange to green, and from green to orange to red.

FIG. 4 is a graph showing the current flowing through the red LED 20 and the green LED 21 with respect to the temperature difference from the set value as a ratio to the rated current. In the figure, Ir is for the red LED 20, and g is for the green LED 21. As can be understood from the graph, the temperature region ■ close to the set value exhibits an orange color, and the lower the temperature is below the set value, the more green the color becomes. The strong green region @ is near the lower limit (-2° C.) temperature. On the other hand, the red color becomes stronger as the temperature rises higher than the set value, and the region O where the red color is strong is near the upper limit temperature (+2° C.). However, the predetermined temperature difference (±2
℃), and the temperature difference is as much as ±4℃.

Area that is completely red■ and area that is completely green■
appears. Therefore, when the color is red, the temperature inside the refrigerator is too high.

Also, when it is green, it can perform an abnormal temperature detection function that can recognize an abnormal temperature that is too low.

The situation in which the temperature inside the refrigerator can be seen in an analog way as a change in hue is that even if the set temperature inside the refrigerator is freely changed using the operation knob 2 for setting the temperature inside the refrigerator, the same analog amount (
It is convenient to be able to see it as a change in hue (hue).

(G) Effects of the Invention As described above, according to the present invention, the temperature inside the refrigerator is detected, and based on the detected temperature, a temperature sensor involved in controlling the cooling device, such as a compressor, is used, and the detected temperature information is used. By controlling the two-color light emitting diode to emit light, the difference between the temperature sensor's temperature and the set temperature inside the refrigerator is displayed in an analog way as a change in hue, so you can see at a glance whether the cooling function is working properly or not. This allows refrigerator users to use the refrigerator with peace of mind. Moreover, since this analog change is uniform even if the set internal temperature is changed, temperature management can be performed reliably no matter what temperature is set. Furthermore, if the temperature inside the refrigerator changes beyond a certain temperature range, by setting the two-color light emitting diode to emit light in one of the two colors, it is possible to have an abnormal temperature detection function, making it possible to respond to abnormal temperatures. It is also possible to quickly achieve this.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view of a refrigerator door in which an internal temperature display section and a temperature setting child according to the present invention are arranged, FIG. 2 is a front view of a two-color light emitting diode, and FIG. 3 is a diagram showing the inside of a refrigerator according to the present invention. The circuit configuration diagram related to the temperature display device, Figure 4 shows the temperature difference between the set value and the
It is a graph showing the current flowing through color (green/red) light emitting diodes as a ratio to the respective rated current values. 1...Temperature display section, 2.Operation knob for setting internal temperature,
10...Two-color light emitting diode, 12...Thermistor,
20...Red LED, 21...Green LED.

Claims (2)

[Claims] (1) A temperature sensor that detects the temperature inside the refrigerator and outputs detected temperature information based on the detected temperature, a temperature setting means that sets the temperature inside the refrigerator to a desired temperature, and two light emitting parts of different hues.
The driving current of the two-color light emitting element and each light emitting part is adjusted based on the temperature information detected by the temperature sensor, and as the temperature changes from a low temperature range to a high temperature range within a predetermined temperature range including the set temperature, A control circuit section that controls light emission so that one light emitting section is strengthened and the other light emitting section is weakened, and the two-color light emitting element is arranged on the back side, and a hue that changes depending on the degree of light emission of both light emitting sections is displayed. An internal temperature display device characterized by comprising a temperature display section. (2) When the temperature sensor detects an abnormal state of high or low temperature in which the internal temperature abnormally exceeds a predetermined temperature range, the temperature display section displays only one of the luminescent colors. 2. The refrigerator temperature display device according to claim 1, wherein the internal temperature display device is configured to display a temperature in a refrigerator.