Refrigerator

Abstract

This refrigerator comprises: a water supply tank that stores water to be supplied to an ice tray; a sensor electrode that is of a shape having a width which varies in the height direction, and that detects a capacitance in the water supply tank; and a control device that determines the water level of the water supply tank by comparing a water supply decrease amount, which is the difference in capacitance between before and after supplying water from the water supply tank to the ice tray, with a reference decrease amount, which is set for the water supply decrease amount.

Description

refrigerator

[0001] This technology relates to a refrigerator with an ice-making function, and in particular to determining the water level in a water supply tank that stores water for making ice inside the refrigerator.

[0002] One method for determining the water level in a container is to measure the capacitance of the container. Specifically, the capacitance of the container is measured using a capacitance detection electrode installed near the container, and the water level is determined from the relationship between the magnitude of the capacitance and the water level.

[0003] The problem here is that capacitance measurements are affected not only by the water level in the container, but also by the surrounding environment, including the container. For example, when determining the water level in a refrigerator's water tank that stores water to supply to ice trays, food items with a high water content may be placed around the water tank. In this case, the capacitance measurement will be higher than usual. For this reason, the water level may not be accurately determined from the capacitance measurement.

[0004] As a technique for addressing such problems, for example, a method is disclosed in which two electrodes of different lengths are provided and the water level in a container is estimated from the correlation between the capacitances detected and measured by the two electrodes (see, for example, Patent Document 1). With this method, the water level is not determined directly using the measured capacitance value, so the influence of the environment around the container can be eliminated.

[0005] In addition, a method has been shown in which an electrode is provided for each water level to be checked, and the water level is determined by the appearance of an inflection point in the capacitance at each electrode (see, for example, Patent Document 2). This method also does not directly use the measured capacitance value to determine the water level, so it can eliminate the influence of the surrounding environment.

[0006] Patent No. 6598171 Patent No. 6756061

[0007] The most common usage pattern for a water tank installed in a refrigerator is to start with the tank full, then make ice, and once the water in the tank is empty, for example, the water is refilled to full capacity. In this type of usage, the above-mentioned conventional method can determine the water level as intended.

[0008] However, some refrigerator users start using the refrigerator with a full water tank, make ice several times, and then the ice storage box becomes full. They stop using the refrigerator for a while, and then, once there is some free space in the ice storage box, they fill the water tank again and resume using the refrigerator. In this case, the water level in the water tank will remain close to full. Other users will fill the water tank with a small amount of water, make ice several times, stop using the refrigerator, and then, after a while, add a small amount of water to the water tank and resume using the refrigerator. In this case, the water level in the water tank will remain close to the bottom of the tank.

[0009] In this way, there are cases where the water level displacement is fixed in a narrow area near the top or bottom of the water supply tank. In such cases, the methods of the above-mentioned patent documents may not be able to determine the water level as intended. For example, the method of Patent Document 1 may not be able to obtain a correlation equation between the two electrodes. Furthermore, the method of Patent Document 2 may not be able to capture the inflection point of the capacitance during use.

[0010] Therefore, with the above-mentioned method, it is difficult to determine whether the water level is low, meaning there is little water left, or high, meaning there is ample water, unless the capacitance value and water volume value are calibrated for each container configuration. While this could be addressed by increasing the number of electrodes, because refrigerators are consumer products, it is desirable to be able to determine the water level with as simple a configuration as possible, without increasing the number of electrodes.

[0011] Therefore, in order to solve the above problem, an object is to provide a refrigerator that makes it easier to grasp the water level in the water tank.

[0012] The disclosed refrigerator comprises a water supply tank for storing water to be supplied to the ice tray, a sensor electrode having a shape with a width that varies in the height direction and for detecting the capacitance in the water supply tank, and a control device for determining the water level in the water supply tank by comparing the amount of water supply descent, which is the difference in capacitance before and after water is supplied from the water supply tank to the ice tray, with a reference amount of water supply descent set for the amount of water supply descent.

[0013] In the disclosed refrigerator, the control device determines the water level of the water tank based on the difference between the amount of capacitance decrease due to water supply between a reference amount and a water supply amount, using the capacitance of the water tank obtained from a sensor electrode with a shape that varies in width in the height direction. By comparing the amount of capacitance decrease from a single sensor electrode, the control device can eliminate the influence of the surrounding environment and perform a more accurate water level determination. Furthermore, even when the water tank has a narrow water level range and the user repeatedly supplies water to the ice tray and pours water into the water tank, the simple configuration allows for an approximate grasp of the water level in the water tank.

[0014] 1 is a diagram illustrating an example of a refrigerant circuit 2 included in a refrigerator 1 according to embodiment 1. FIG. 2 is an exterior front view illustrating an example configuration of a refrigerator 1 according to embodiment 1. FIG. 3 is an exterior front view illustrating each storage compartment of the refrigerator 1 shown in FIG. 2. FIG. 4 is a side perspective view of the refrigerator 1 shown in FIG. 2 taken along the line A-A. FIG. 5 is a front schematic view illustrating a state in which the refrigerator compartment door 11 of the refrigerator compartment 10 shown in FIG. 2 is open. FIG. 6 is a side perspective view illustrating another example of the refrigerator 1 according to embodiment 1. FIG. 7 is a cross-sectional schematic view of an automatic ice maker 200 in the refrigerator 1 according to embodiment 1. FIG. 8 is a diagram illustrating the positional relationship between a water supply tank 210 and a sensor electrode 300 according to embodiment 1. FIG. 9 is a diagram illustrating the relationship between a control board 100 and devices connected by signals to the control board 100 in the refrigerator 1 according to embodiment 1. FIG. 10 is a diagram mainly illustrating the configuration of a control device 110. FIG. 11 is a diagram illustrating the relationship between the water level and capacitance of a water supply tank 210 according to embodiment 1. FIG. 12 is a diagram illustrating the process flow related to determining the water level of the water supply tank 210 according to embodiment 1. FIG. 13 is a diagram illustrating the process flow of a heat generation amount adjustment function unit 114 according to embodiment 1. FIG. 10 is a diagram showing the positional relationship between the water supply tank 210 and the sensor electrode 300 installed on the peripheral member 16 in the refrigerator 1 according to embodiment 2. FIG. 11 is a diagram showing the process flow relating to determining whether the amount of water in the water supply tank 210 is insufficient according to embodiment 2. FIG. 12 is a diagram explaining the process flow of the heat generation amount adjustment function unit 114 according to embodiment 2. FIG. 13 is a diagram showing the positional relationship between the water supply tank 210 and the sensor electrode 300 installed on the peripheral member 16 in the refrigerator 1 according to embodiment 3. FIG. 14 is a diagram showing the process flow relating to determining whether the amount of water in the water supply tank 210 is excessive according to embodiment 3. FIG. 15 is a diagram explaining the process flow of the heat generation amount adjustment function unit 114 according to embodiment 3. FIG. 16 is a diagram showing the shape of the sensor electrode 300 according to embodiment 4. FIG. 17 is a diagram showing other shapes of the sensor electrode 300 according to embodiment 4.

[0015] A refrigerator according to the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to the following embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure. The present disclosure also includes all possible combinations of configurations among the configurations shown in the following embodiments and their modifications. In each drawing, identical reference numerals denote identical or equivalent components, and this applies throughout the entire specification. The present disclosure also includes other processes that can be performed between the processes performed in each embodiment. The surface seen from the front of the refrigerator is referred to as the front or front surface, and the surface opposite the front surface is referred to as the rear surface. The upper surface of the refrigerator viewed from the front side is referred to as the top surface, and the surface opposite the top surface is referred to as the bottom surface. The left and right surfaces of the refrigerator viewed from the front side are referred to as sides. In the following description, the top of the drawings will be referred to as "up" and the bottom as "bottom." To facilitate understanding, terms that primarily represent directions when viewing the refrigerator from the front side (e.g., "right," "left," "front," "rear," etc.) will be used as appropriate. However, these terms are for illustrative purposes only and do not limit the disclosure. When viewing the refrigerator from the front side, the vertical direction is the height direction, and the front-to-back direction is the depth direction. The direction perpendicular to the height direction of each component is the width direction. Here, "perpendicular" does not have to be strictly perpendicular, and includes cases where the component is approximately perpendicular. The relative dimensional relationships, shapes, materials, etc. of each component in each drawing may differ from those in the actual product.

[0016] Embodiment 1. Figures 1 to 8 are diagrams illustrating a refrigerator 1 according to Embodiment 1 and the configuration inside the refrigerator 1. Figure 1 is a diagram illustrating an example of a refrigerant circuit 2 included in the refrigerator 1 according to Embodiment 1. The refrigerator 1 according to Embodiment 1 includes a compressor 3, a heat sink 4, an expansion device 5, and a cooler 6. The compressor 3, the heat sink 4, the expansion device 5, and the cooler 6 are connected by refrigerant piping to form the refrigerant circuit 2 in which the refrigerant circulates.

[0017] The compressor 3 draws in a refrigerant, compresses it, and discharges it. The capacity of the compressor 3 can be changed by adjusting the rotation speed. The radiator plate 4 is a heat exchanger that exchanges heat between the refrigerant and outside air to release the heat of the refrigerant to the outside air. The expansion device 5 decompresses the refrigerant to expand it. The expansion device 5 is, for example, a capillary tube or an electronic expansion valve. FIG. 1 schematically shows a case where the expansion device 5 is a capillary tube. The cooler 6 is a heat exchanger that cools the air inside the refrigerator 1 by exchanging heat between the air inside the refrigerator 1 and the refrigerant. In the refrigeration cycle in which the refrigerant circulates through the refrigerant circuit 2, the radiator plate 4 functions as a condenser, and the cooler 6 functions as an evaporator.

[0018] FIG. 2 is an exterior front view showing one configuration example of refrigerator 1 according to embodiment 1. FIG. 3 is an exterior front view showing each storage compartment of refrigerator 1 shown in FIG. 2. FIG. 3 shows refrigerator 1 shown in FIG. 2 with its doors removed, with the boundaries between adjacent doors indicated by dashed lines. As shown in FIG. 3, refrigerator 1 includes refrigerator main body 1a, refrigerator compartment door 11, switchable compartment door 21, ice-making compartment door 31, freezer compartment door 41, and vegetable compartment door 51. Refrigerator main body 1a includes refrigerator compartment 10, switchable compartment 20, ice-making compartment 30, freezer compartment 40, and vegetable compartment 50 as storage compartments for accommodating food and other stored items. Refrigerator main body 1a includes inner box 1b, outer box 1c, and insulating material 1d between inner box 1b and outer box 1c.

[0019] The opening of the refrigerator compartment 10 shown in FIG. 3 is provided with a refrigerator compartment door 11 as shown in FIG. 2. The refrigerator compartment door 11 of the refrigerator compartment 10 is a double-hinged door. The refrigerator compartment door 11 has a left door 11a and a right door 11b. The refrigerator compartment door 11 is not limited to a double-hinged door, but may be a single-hinged door. The opening of the switchable compartment 20 shown in FIG. 3 is provided with a switchable compartment door 21 as shown in FIG. 2. The opening of the ice-making compartment 30 shown in FIG. 3 is provided with an ice-making compartment door 31 as shown in FIG. 2. The opening of the freezer compartment 40 shown in FIG. 3 is provided with a freezer compartment door 41 as shown in FIG. 2. The opening of the vegetable compartment 50 shown in FIG. 3 is provided with a vegetable compartment door 51 as shown in FIG. 2.

[0020] The refrigerator compartment 10 and the vegetable compartment 50 are maintained at refrigeration temperatures. The refrigeration temperatures are, for example, in the range of approximately 0°C to approximately 10°C. The ice-making compartment 30 and the freezer compartment 40 are maintained at freezing temperatures, which are lower than the refrigeration temperatures. The freezing temperatures are generally in the range of approximately -15°C to approximately -18°C. The switchable compartment 20 is a storage compartment where the user can select whether to store items at the refrigeration temperature or the freezing temperature. Here, FIG. 3 shows, with hatching, the partitions between the storage compartments, including the partition 70 between the refrigerator compartment 10 and the ice-making compartment 30, and the insulating material 1d that covers the refrigerator body 1a including the multiple storage compartments.

[0021] Fig. 4 is a side perspective view of refrigerator 1 shown in Fig. 2 taken along the line A-A. Fig. 4 shows a cross section passing through ice-making compartment 30, and the direction of arrow Y in the figure indicates the depth direction of refrigerator 1. In Fig. 4, hatching indicates partitions between storage compartments, including partition 70 between refrigeration compartment 10 and ice-making compartment 30, and insulating material 1d that covers each door and refrigerator body 1a including the multiple storage compartments.

[0022] As shown in Fig. 4, refrigerator 1 is provided with air passage 60 through which cool air cooled by cooler 6 flows, and blower 61 that supplies the cool air flowing through air passage 60 to each storage compartment. Air passage 60 and blower 61 are provided on the rear side of refrigerator 1. Refrigerator 1 controls a refrigeration cycle that circulates refrigerant through refrigerant circuit 2, and circulates cool air near cooler 6 inside the refrigerator using blower 61, thereby performing a cooling operation to cool the air in multiple storage compartments.

[0023] As shown in Fig. 4, the cooler 6 is equipped with a cooling temperature sensor 6a that detects the temperature of the air being cooled by the cooler 6. A heater 6b that removes frost that has adhered to the cooler 6 is provided below the cooler 6. When energized, the heater 6b heats the air around the cooler 6. This melts and removes the frost that has adhered to the cooler 6. As a result, the cooling capacity of the cooler 6 is restored.

[0024] As shown in Figures 3 and 4, refrigerator compartment 10 is fitted with refrigerator compartment temperature sensor 12 for detecting the temperature of the air within refrigerator compartment 10. A refrigerator compartment damper 13 for regulating the flow rate of cold air flowing into refrigerator compartment 10 from air duct 60 is provided on the rear side of refrigerator compartment 10. A lighting device 14 for illuminating the interior of refrigerator compartment 10 is provided in refrigerator compartment 10. The light source of lighting device 14 is, for example, an LED (Light Emitting Diode). Also provided within refrigerator compartment 10 are a water supply tank 210 for storing water for making ice in automatic ice maker 200, and peripheral components 16 such as storage shelves installed around water supply tank 210, as will be described later.

[0025] Fig. 5 is a front schematic view showing the refrigerator compartment door 11 of the refrigerator compartment 10 shown in Fig. 2 in an open state. When the refrigerator compartment door 11 of the refrigerator compartment 10 is a double-hinged door, the user can open and close the left door 11a and the right door 11b independently, as shown in Fig. 5. In addition, a door switch 15 that detects the open / closed state of the left door 11a and the right door 11b is provided on the front surface of the partition 70 that separates the refrigerator compartment 10 from the ice-making compartment 30 and the switchable compartment 20.

[0026] 2 and 4, an operation panel 500 is provided on the left door 11a of the refrigerator compartment 10 to allow the user to set operating conditions such as the refrigeration temperature and freezing temperature. The operation panel 500 has an input device (not shown) for inputting settings for the operating conditions of the refrigerator 1, and a display device (not shown) that displays the operating conditions of the refrigerator 1. The operation panel 500 may also have a microcomputer (not shown) that controls the input device (not shown) and the display device (not shown).

[0027] As shown in FIGS. 3 and 4 , a freezer compartment temperature sensor 42 is attached to freezer compartment 40 to detect the temperature of the air within freezer compartment 40. A switchable compartment temperature sensor 22 is attached to switchable compartment 20 to detect the temperature of the air within switchable compartment 20. A switchable compartment damper 23 is provided on the rear side of switchable compartment 20 to adjust the flow rate of cool air flowing into switchable compartment 20 from air duct 60. A vegetable compartment temperature sensor 52 is attached to vegetable compartment 50 to detect the temperature of the air within vegetable compartment 50. A vegetable compartment damper 53 is provided on the rear side of vegetable compartment 50 to adjust the flow rate of cool air flowing into vegetable compartment 50 from air duct 60. As shown in FIG. 3 , an ice making compartment temperature sensor 32 is attached to ice making compartment 30 to detect the temperature of the air within ice making compartment 30. An ice making compartment damper 33 is provided on the rear side of ice making compartment 30 to adjust the flow rate of cool air flowing into ice making compartment 30 from air duct 60. Furthermore, refrigerator compartment temperature sensor 12, freezer compartment temperature sensor 42, switchable compartment temperature sensor 22, vegetable compartment temperature sensor 52, ice-making compartment temperature sensor 32, and cooling temperature sensor 6a are, for example, thermistors. Furthermore, refrigerator 1 in embodiment 1 has control board 100 at the top of the rear side, as shown in FIG. 4 . Control board 100 is a board that has control-system devices. Control board 100 will be described later. Refrigerator 1 also has communication device 400 on the ceiling surface. Communication device 400 is a device that transmits and receives wireless signals for communication between external devices such as a smartphone and control device 110, which will be described later.

[0028] 3 and 4, automatic ice maker 200 is installed in ice making compartment 30 and refrigerating compartment 10 of refrigerator 1. Automatic ice maker 200 has water supply tank 210, automatic water supply mechanism 220, ice making tray 230, ice release mechanism 240, and ice storage box 250.

[0029] As described above, water supply tank 210 is installed in refrigerator compartment 10, for example. Water supply tank 210 is a container that stores water used to supply water to ice tray 230 to make ice. Automatic water supply mechanism 220 is a device that pumps water from water supply tank 210 and automatically supplies water to ice tray 230 based on instructions from control device 110, which will be described later. The main components of automatic water supply mechanism 220 are installed in refrigerator compartment 10. Details of automatic water supply mechanism 220 will be described later.

[0030] Ice tray 230, ice release mechanism 240, and ice storage box 250 are installed in ice making chamber 30. Ice tray 230 is a tray that freezes supplied water to produce ice. Ice tray 230 has multiple recesses, for example, due to partitions inside the tray, and can produce, for example, multiple rectangular parallelepiped-shaped ice pieces at one time. Ice release mechanism 240 is a device that rotates ice tray 230 to drop the produced ice from ice tray 230 into ice storage box 250. Ice storage box 250 is a box that stores the produced ice in ice making chamber 30.

[0031] Furthermore, refrigerator 1 according to embodiment 1 includes warming heater 600 and sensor electrode 300. As will be described later, warming heater 600 supplies heat to water supply tank 210 under the control of control device 110 to prevent the water in water supply tank 210 from freezing. Here, water supply tank 210 is assumed to be embedded in refrigerator body 1a between inner box 1b and outer box 1c at a portion of inner box 1b that abuts against water supply tank 210. However, the installation position is not limited thereto, and water supply tank 210 may be installed in peripheral member 16, for example.

[0032] The sensor electrode 300 serves as a sensor for detecting the capacitance of the water supply tank 210. The sensor electrode 300 is made of a thin metal, such as aluminum tape or copper film. Here, one sensor electrode 300 is attached to the surface of the peripheral member 16 opposite the surface that contacts the water supply tank 210, along the tank side surface 211 of the water supply tank 210. However, this is not limiting. For example, the sensor electrode 300 may be attached to the back surface of the inner box 1b. The sensor electrode 300 may also be attached directly to the tank side surface 211 of the water supply tank 210. In this case, the sensitivity of the sensor electrode 300 is increased, but the sensor electrode 300 is exposed. Therefore, for example, from the perspective of design, the sensor electrode 300 may be installed in a location that is not visible to the user. Furthermore, for example, from the perspective of protecting the sensor electrode 300, the sensor electrode 300 may be installed in a location that is not directly accessible to the user. In this case, multiple sensor electrodes 300 may be used. Having more sensor electrodes 300 can improve the accuracy of the determination. However, a single sensor electrode 300 requires less wiring and simplifies the design. The sensor electrode 300 will be described in more detail later.

[0033] FIG. 6 is a side perspective view showing another example of refrigerator 1 according to embodiment 1. FIG. 6 shows the same refrigerator 1 as FIG. 2, viewed from the A-A cross section. As shown in FIG. 6, water supply tank 210 can also be embedded in partition 70. In this case, sensor electrode 300 is installed, for example, on the side of recess 71 in partition 70 for embedding water supply tank 210. Embedding water supply tank 210 in partition 70 makes sensor electrode 300, in particular, less susceptible to the effects of the surrounding environment. For this reason, a structure in which water supply tank 210 is embedded in partition 70 is expected to provide more accurate water level determination.

[0034] Fig. 7 is a cross-sectional schematic diagram of automatic ice maker 200 in refrigerator 1 according to embodiment 1. Fig. 7 shows automatic ice maker 200 cut at a position just before water supply pipe 222. More specifically, this is the position that passes through the bottom surface of the recess in the second row from the front of ice tray 230.

[0035] Water supply pipe 222 passes through partition 70 and is provided between ice tray 230 and water supply tank 210. Outlet 224 of water supply pipe 222 is disposed diagonally below and to the left of inlet 223.

[0036] 7, water supply pipe 222 is positioned so that water from outlet 224 hits a sloped surface provided toward the center of ice making tray 230 in a recessed portion that is the second row from the front and is located on the water supply pipe 222 side among multiple recessed portions in ice making tray 230. By positioning the point where water supplied from outlet 224 hits the tray at a distance equivalent to one recessed portion on the water supply pipe 222 side from the edge of ice making tray 230, it is possible to prevent the water supplied from outlet 224 from spilling out of ice making tray 230.

[0037] 7 has a step formed inside, with a first step 212 that has a shallow water depth when filled with water, and a second step 213 that is adjacent to the first step 212 and has a deeper water depth than the first step 212. The second step 213 is formed adjacent to the first step 212 in the left-right direction in the water supply tank 210. A water supply pump 221 is disposed on the second step 213 so as to be in contact with the wall surface of the water supply tank 210 in the front-rear direction. The first step 212 is formed to be higher than the water supply port 225 of the water supply pump 221 disposed on the second step 213.

[0038] The first step 212 is formed so as to slope downward toward the second step 213, so that water on the first step 212 flows to the second step 213. For example, the first step 212 is formed so as to slope downward by about 7° with respect to the horizontal direction.

[0039] The first step 212 is formed so that the bottom surface slopes downward from one wall surface of the water supply tank 210 to the opposing other wall surface. In this case, the one wall surface of the water supply tank 210 is the wall surface that contacts the water supply pump 221 arranged in the second step 213.

[0040] The second step 213 is formed taking into consideration the width of the water supply pump 221 so that the water supply pump 221 can be disposed therein. The second step 213 is formed so that a portion of the bottom surface slopes upward from one wall surface of the water supply tank 210 where the water supply pump 221 is disposed to the other opposing wall surface. Here, the remaining portion of the bottom surface of the second step 213 is the portion where the water supply pump 221 is disposed. In other words, the bottom surface of the second step 213, excluding the portion where the water supply pump 221 is disposed, is formed so that the bottom surface slopes upward as it becomes further away from the water supply pump 221.

[0041] By forming the first step portion 212 and the second step portion 213 with an incline, etc., a continuous surface is formed in the water supply tank 210 between the lowest bottom surface of the first step portion 212 and the highest bottom surface of the second step portion 213.

[0042] Next, the ice-making operation of automatic ice maker 200 will be described. When refrigerator 1 starts operating, for example, control device 110 of control board 100 causes automatic ice maker 200 to start the automatic ice-making cycle. In the automatic ice-making cycle, automatic water supply mechanism 220 first draws a certain amount of water from water supply tank 210 and automatically supplies it to ice tray 230 in ice making compartment 30. The supplied water is cooled and frozen in ice tray 230. At this time, an ice temperature sensor (not shown) or the like detects the temperature of the water supplied to ice tray 230. Then, when control device 110 determines, based on the temperature detected by the ice temperature sensor, that the water temperature has sufficiently dropped below a predetermined temperature and reached the temperature of ice, it determines that the ice is ready. Control device 110 then causes ice release mechanism 240 to release the completed ice from ice tray 230. The released ice falls into ice storage box 250 installed below ice tray 230 and is stored there.

[0043] Control device 110 causes automatic ice maker 200 to repeatedly execute the automatic ice making cycle described above, and stops the automatic ice making cycle when a sufficient amount of ice has accumulated in ice storage box 250. Control device 110 periodically checks whether the amount of ice stored in ice storage box 250 is sufficient using an ice detection mechanism (not shown). When control device 110 determines that the amount of stored ice is no longer sufficient, it causes automatic ice maker 200 to execute the automatic ice making cycle again.

[0044] 8 is a diagram illustrating the positional relationship between the water supply tank 210 and the sensor electrode 300 according to the first embodiment. For ease of explanation, the water supply tank 210 will be described as a rectangular parallelepiped container. As described above, the sensor electrode 300 is a sensor that detects the capacitance of the water supply tank 210. As will be described later, the sensor electrode 300 sends an electrode signal based on the detected capacitance to the control device 110.

[0045] As shown in FIG. 8 , the width w of the sensor electrode 300, which is perpendicular to the height direction, varies depending on the position in the height direction. The width w of the sensor electrode 300 gradually narrows in the height direction from the electrode upper end 310 to the electrode connection portion 320, and gradually widens from the electrode connection portion 320 to the electrode lower end 330. Here, the portion of the sensor electrode 300 above the electrode connection portion 320 is referred to as the upper electrode portion 340, and the portion below the electrode connection portion 320 is referred to as the lower electrode portion 350. The electrode connection portion 320 is the center of the sensor electrode 300 in the height direction, and corresponds to the center of the water level in the water supply tank 210. However, the position of the electrode connection portion 320 is not limited to the center.

[0046] Furthermore, the sensor electrode 300 in the first embodiment is installed in a positional relationship in the height direction such that the position of the electrode upper end 310 corresponds to and coincides with the top of the water supply tank 210. The sensor electrode 300 is also installed in a positional relationship such that the position of the electrode lower end 330 corresponds to and coincides with the bottom (inner bottom surface) of the water supply tank 210. How the water level in the water supply tank 210 is determined will be described in detail later.

[0047] 9 is a diagram showing the relationship between control board 100 and devices connected by signals to control board 100 in refrigerator 1 according to Embodiment 1. As described above, refrigerator 1 has control board 100. Control board 100 is a board that has control system devices such as control device 110 and drive element 120.

[0048] The control device 110 controls the devices in the refrigerator 1, controlling the temperature inside the refrigerator, etc. The control device 110 controls the compressor 3, the blower 61, and the heater 6b based on temperatures detected by the refrigerator compartment temperature sensor 12, the freezer compartment temperature sensor 42, the selectable compartment temperature sensor 22, the vegetable compartment temperature sensor 52, the ice-making compartment temperature sensor 32, and the cooling temperature sensor 6a. The control device 110 also controls the opening and closing of the refrigerator compartment damper 13, the selectable compartment damper 23, the vegetable compartment damper 53, and the ice-making compartment damper 33 based on the temperature signals, thereby adjusting the amount of cool air sent to each storage compartment. Furthermore, the control device 110 controls the illumination of the lighting device 14 based on an opening / closing signal sent from the door switch 15. The control device 110 adjusts the amount of current (operation rate) in the drive element 120 to control the heat output of the warming heater 600. The control device 110 is also connected to the communication device 400, enabling it to transmit and receive signals to and from external devices. Furthermore, control device 110 receives an operation signal from operation panel 500 and sends a display signal to operation panel 500. In particular, control device 110 in the first embodiment determines the capacitance of sensor electrode 300 based on an electrode signal sent from sensor electrode 300, as will be described later.

[0049] Here, the control device 110 includes, as hardware, a microcomputer having a control arithmetic processing unit 110a such as a CPU (Central Processing Unit). The control device 110 also includes a storage device 110b. The storage device 110b includes a volatile storage device such as a RAM (Random Access Memory) that can temporarily store data. The storage device 110b also includes a non-volatile auxiliary storage device such as a flash memory that can store data long-term, including a ROM (Read Only Memory). The storage device 110b also includes program data that describes the processing procedures to be performed by each functional unit, which will be described later. The control arithmetic processing unit 110a then executes processing based on the program data to realize the processing of each functional unit.

[0050] FIG. 10 is a diagram mainly showing the configuration of the control device 110. As described above, the control device 110 controls the temperature inside the refrigerator 1, and in this example, it particularly includes a water level determination function unit 111, a heat generation amount adjustment function unit 114, a water volume shortage determination function unit 112, and an excess water volume determination function unit 113. The water level determination function unit 111 determines the water level inside the water supply tank 210 based on the capacitance of the water supply tank 210 detected by the sensor electrode 300. The water volume shortage determination function unit 112 determines whether the amount of water remaining in the water supply tank 210 for the next automatic water supply is sufficient. The excess water volume determination function unit 113 determines whether the amount of water dispensed into the water supply tank 210 is excessive. The heat generation amount adjustment function unit 114 adjusts the heat generation amount of the warming heater 600.

[0051] 11 is a diagram showing the relationship between the water level and capacitance in the water supply tank 210 according to the first embodiment. Next, the water level determination performed by the water level determination function unit 111 of the control device 110 will be described. When viewed from the side, the area where the water in the water supply tank 210 overlaps with the sensor electrode 300 decreases as the water level in the water supply tank 210 drops during automatic water supply. This decrease appears as a decrease in capacitance before and after water supply.

[0052] As described above, the sensor electrode 300 has a shape with a width w that varies in the height direction. Therefore, even if the amount of decrease in the water level is the same, the amount of decrease in the area where the water in the water supply tank 210 overlaps with the sensor electrode 300 varies depending on the water level in the water supply tank 210. For example, the shape of the electrode upper portion 340 of the sensor electrode 300 gradually narrows in width w from the electrode upper end portion 310 to the electrode connection portion 320. Therefore, when the water level in the water supply tank 210 remains above the electrode connection portion 320 of the sensor electrode 300, the amount of decrease in the area where the water in the water supply tank 210 overlaps with the sensor electrode 300 decreases each time water is supplied. Therefore, the amount of decrease in capacitance due to the electrode signal of the sensor electrode 300 decreases.

[0053] Therefore, in refrigerator 1 according to the first embodiment, a water supply drop amount (previous drop amount) is set as the reference drop amount, which is the difference between the capacitances detected by sensor electrode 300 before and after the previous water supply by automatic water supply mechanism 220 to ice tray 230, and is stored in storage device 110b. Here, the water supply drop amount is the difference between the capacitances detected by sensor electrode 300 before and after the previous water supply by automatic water supply mechanism 220 to ice tray 230. Water level determination function unit 111 then compares the previous drop amount with the current drop amount. The current drop amount is the drop in capacitance measured by sensor electrode 300 before and after the most recent water supply to ice tray 230. If the current drop amount is smaller than the previous drop amount, water level determination function unit 111 can determine that the water level in water tank 210 is above electrode connection unit 320. Here, the position of the electrode connection part 320 corresponds to the center part of the water level of the water supply tank 210, so the water level is "medium or higher."

[0054] On the other hand, the shape of the sensor electrode 300 at the electrode lower portion 350 gradually widens in width w from the electrode connection portion 320 to the electrode lower end portion 330. As a result, the amount of capacitance decrease due to the electrode signal of the sensor electrode 300 increases. Therefore, if the amount of decrease this time is greater than the amount of decrease the previous time, the water level determination function unit 111 can determine that the water level in the water supply tank 210 is below the electrode connection portion 320. In this way, the water level determination function unit 111 can roughly determine the water level in the water supply tank 210.

[0055] Here, the water level determination function unit 111 may determine that the water level of the water supply tank 210 due to the previous water supply was above the electrode connection unit 320, and that the water level of the water supply tank 210 due to the current water supply is below the electrode connection unit 320. In this case, it is considered that the water level of the water supply tank 210 that decreased during the previous water supply was near the electrode connection unit 320. At this time, it is considered that the water level of the water supply tank 210 due to the current water supply will be a water level that is lower than the position corresponding to the electrode connection unit 320 by the amount of one water supply. Furthermore, it is considered that the water level of the water supply tank 210 due to the next water supply will be a water level that is lower than the water level of the water supply tank 210 due to the current water supply by the amount of one water supply. From this, for example, after the water level determination performed by the water level determination function unit 111 is switched to a level below the electrode connection unit 320, it is possible to more specifically grasp the water level of the water supply tank 210 using the position of the electrode connection unit 320 as a reference. If it is known how many remaining water dispenses the water level corresponding to the position of the electrode connection part 320 corresponds to, it is possible to derive the remaining number of water dispenses by counting or the like.

[0056] 12 is a diagram illustrating the flow of processing related to determining the water level of the water supply tank 210 according to Embodiment 1. The water level determination processing shown in FIG. 12 will be described as being performed by the water level determination function unit 111 of the control device 110.

[0057] When refrigerator 1 starts operating, water level determination function unit 111 starts monitoring the capacitance based on the electrode signal from sensor electrode 300 (step S1). If water level determination function unit 111 determines based on the electrode signal that the capacitance has increased, for example, due to pouring water (step S2), it resets the data on the previous amount of descent stored in storage device 110b by deleting it or the like, and changes it to undetermined (step S3).

[0058] On the other hand, when automatic water supply mechanism 220 automatically supplies water during the automatic ice making cycle, the amount of water in water supply tank 210 decreases. As the water decreases, the water level in water supply tank 210 drops, and the area of ​​the sensor electrode 300 that overlaps with the water decreases. As a result, the capacitance indicated by the electrode signals before and after automatic water supply decreases. Based on the electrode signals, water level determination function unit 111 determines whether the capacitance has decreased and whether automatic water supply has occurred (step S4). If water level determination function unit 111 determines that automatic water supply has occurred, it calculates the amount of capacitance decrease this time (step S5).

[0059] The water level determination function unit 111 compares the calculated current drop amount with the previous drop amount stored as data in the storage device 110b (step S6). If the water level determination function unit 111 determines that the data on the previous drop amount is not stored in the storage device 110b (step S7), it sets the calculated current drop amount as the data on the previous drop amount, which is the reference drop amount, and stores it in the storage device 110b (step S11), and continues processing.

[0060] The water level determination unit 111 then determines whether the previous amount of drop is equal to or greater than the current amount of drop (step S8). If the water level determination unit 111 determines that the previous amount of drop is not equal to or greater than the current amount of drop, it determines that the approximate water level is "below medium" (step S9). Here, "medium water level" means that the water level in the water supply tank 210 is at a water level corresponding to the electrode connection part 320 in the center part of the electrode in the vertical direction. On the other hand, if the water level determination unit 111 determines that the previous amount of drop is equal to or greater than the current amount of drop, it determines that the approximate water level is "above medium" (step S10). The water level determination unit 111 then sets the calculated current amount of drop as data on the previous amount of drop, stores it in the storage device 110b (step S11), and continues processing.

[0061] The water level determination function unit 111 notifies or alerts the user based on the determination result (step S12). For example, the water level determination function unit 111 sends a communication signal including the determination result via the communication device 400 and displays it on a display device (not shown) of an external device such as a smartphone to notify the user. Alternatively, the water level determination function unit 111 sends a display signal including the determination result to the operation panel 500 and displays it on the operation panel 500 to notify the user. Based on the determination result, the water level determination function unit 111 may convert the result into information that is easy for the user to understand, such as "how many times ice can be made remaining," and notify or alert the user of the converted information. The control device 110 may also control the blower 61, the ice-making chamber damper 33, and the like.

[0062] 13 is a diagram illustrating the processing flow of the heat generation amount adjustment function unit 114 in embodiment 1. When the refrigerator 1 starts operating, the heat generation amount adjustment function unit 114 starts monitoring the determination result of the water level determination function unit 111 (step S21). When the heat generation amount adjustment function unit 114 determines that there has been a change in the water level determination of the water level determination function unit 111 (step S22), the heat generation amount adjustment function unit 114 determines whether the water level is "below medium" (step S23).

[0063] When the heat generation amount adjustment function unit 114 determines that the water level determination function unit 111 has determined that the water level is "below medium," it sets the heat generation amount of the heat retention heater 600 to "heat generation amount for below medium" (step S24) and adjusts the amount of power supplied to the drive element 120 (step S26). On the other hand, when the heat generation amount adjustment function unit 114 determines that the water level determination function unit 111 has determined that the water level is not "below medium," it sets the heat generation amount of the heat retention heater 600 to "heat generation amount for medium or higher" (step S25) and adjusts the amount of power supplied to the drive element 120 (step S26). The drive element 120 controls the heat generation amount of the heat retention heater 600 based on the adjusted amount of power supplied.

[0064] Here, the setting data for the "medium or higher heat generation amount" and the "medium heat generation amount" are set in advance and stored in the storage device 110b or the like of the control device 110. The amounts of current flowing through the drive elements 120 corresponding to the "medium or higher heat generation amount" and the "below-medium heat generation amount" are calculated by dividing the "medium or higher heat generation amount" and the "below-medium heat generation amount" by the rated heat generation amount of the heater 600. Generally, the smaller the amount of water in the water supply tank 210, the less heat generation is required to raise the water temperature in the water supply tank 210, so the "below-medium heat generation amount" can be set to be lower than the "medium or higher heat generation amount."

[0065] As described above, according to the refrigerator 1 of the first embodiment, the water level determination function unit 111 of the control device 110 determines the water level in the water supply tank 210 based on a comparison of the magnitude of the capacitance decrease before and after the current water supply with the magnitude of the capacitance decrease before and after the previous water supply. Therefore, the water level can be determined after two water supplies. Therefore, the water level in the water supply tank 210 can be grasped even when the refrigerator is used in a manner that involves repeating ice making and water filling into the water supply tank 210 relatively few times. Furthermore, the water level determination function unit 111 of the control device 110 can determine the water level in the water supply tank 210 based on the capacitance of a single sensor electrode 300. This simplifies the configuration related to water level determination. Furthermore, connecting a single sensor electrode 300 to the control device 110 can suppress increases in the cost of harnesses and other components. Furthermore, the water level determination function unit 111 determines the water level based on the magnitude of the decrease in capacitance when automatic water supply is performed, rather than the capacitance itself, so that the water level determination can be performed while suppressing the influence of capacitance fluctuations due to changes in the surrounding environment. Also, the heat generation amount adjustment function unit 114 in the first embodiment can adjust the heat generation amount of the warming heater 600 to a necessary and sufficient amount according to the amount of water in the water supply tank 210. This allows the refrigerator 1 to save power consumption.

[0066] Embodiment 2 In embodiment 2, a description will be given of the determination of a water shortage in water supply tank 210 performed by water shortage determination function unit 112 of control device 110 described in Fig. 10. When water shortage determination function unit 112 determines that there is not enough water left in water supply tank 210 to fill ice tray 230, it determines that there is a water shortage.

[0067] Fig. 14 is a diagram showing the positional relationship between water supply tank 210 and sensor electrode 300 attached to peripheral member 16 in refrigerator 1 according to embodiment 2. In refrigerator 1 according to embodiment 2, in response to the water shortage determination by water shortage determination function unit 112, the position of electrode lower end 330 of sensor electrode 300 is adjusted so that it coincides with the water level when ice tray 230 is filled with water in water supply tank 210. For this reason, as shown in Fig. 14, peripheral member 16 has alignment shape portion 16a. Alignment shape portion 16a aligns sensor electrode 300 so as to prevent misalignment when sensor electrode 300 is attached to peripheral member 16 for installation.

[0068] For example, in refrigerator 1 in the first embodiment, sensor electrode 300 is installed so that the position of electrode lower end 330 coincides with the bottom of water supply tank 210. In this case, even if the amount of water remaining in water supply tank 210 after a certain automatic water supply is less than enough to fill ice tray 230, the capacitance will decrease when the next automatic water supply is performed.

[0069] Therefore, after water is supplied to ice tray 230 in one automatic water supply, whether or not there will be a shortage of water in water supply tank 210 in the next automatic water supply is determined based on the absolute value of the amount of capacitance decrease in that time. In this case, the determination result in water level determination function unit 111 is affected by fluctuations in the surrounding environment, and the amount of decrease may fluctuate, so it may not be possible to make an accurate determination.

[0070] Therefore, the water level determination function unit 111 may not be able to determine whether the water level is insufficient until the water supply tank 210 is empty. If the water supply tank 210 is empty, the capacitance during automatic water supply does not decrease. Therefore, if the automatic water supply mechanism 220 repeats automatic water supply until the capacitance stops decreasing, the water level determination function unit 111 can determine whether the water level in the water supply tank 210 is insufficient, regardless of the influence of the surrounding environment.

[0071] However, unless there is exactly enough water for one fill in water supply tank 210, this will eventually result in a shortage of water to be supplied to ice tray 230, delaying the timing of the water shortage determination. Therefore, as shown in FIG. 14 , in refrigerator 1 according to embodiment 2, the position of electrode lower end 330 of sensor electrode 300 corresponds to the water level when water supply tank 210 is filled with enough water to fill ice tray 230. In this case, if the amount of water in water supply tank 210 is less than the amount of water to fill ice tray 230 after a certain water supply, the water level in water supply tank 210 will be located below electrode lower end 330 of sensor electrode 300. Therefore, the decrease in capacitance decreases significantly. Therefore, water level determination function unit 111 can determine whether there is a shortage of water to supply to ice tray 230 before the next automatic water supply is performed.

[0072] 15 is a diagram showing the flow of processing related to determining whether there is a shortage of water in the water supply tank 210 according to embodiment 2. The determination of whether there is a shortage of water is mainly performed by the water shortage determination function unit 112 based on the calculation results of the water level determination function unit 111, etc.

[0073] As described in the first embodiment, when the water level determination function unit 111 of the control device 110 determines that automatic water supply has been performed (step S31), it calculates the current water descent amount (step S32). The water volume shortage determination function unit 112 of the control device 110 determines whether the current water descent amount calculated by the water level determination function unit 111 is less than the descent amount threshold (step S33). Here, the descent amount threshold is a threshold value set in advance through experiments or the like to determine whether there is a water descent amount, and is a value smaller than the calculated water descent amount obtained when the water level in the water supply tank 210 is at or above the electrode lower end 330. When the water volume shortage determination function unit 112 determines that the descent amount is not less than the descent amount threshold, it determines that there is no water descent amount (step S36) and continues processing.

[0074] On the other hand, if the water level deficiency determination function unit 112 determines that the value of the decrease is less than the set deficiency threshold, it determines that there is a water deficiency (step S34). Then, the water level deficiency determination function unit 112 notifies or alerts the user that there is a water deficiency (step S35) and prompts them to fill the water supply tank 210. For example, the water level determination function unit 111 sends a communication signal via the communication device 400 and displays the information on a display device (not shown) of an external device such as a smartphone to notify the user. Also, for example, the water level determination function unit 111 sends a display signal to the operation panel 500 and displays the above-mentioned information on the operation panel 500 to notify the user. The water level determination function unit 111 may also control devices within the refrigerator 1.

[0075] 16 is a diagram illustrating the processing flow of the heat generation amount adjustment function unit 114 according to embodiment 2. The heat generation amount adjustment function unit 114 according to embodiment 2 adjusts the heat generation amount of the warmth heater 600 based on the determination result of the water amount shortage determination function unit 112. Here, in the case of a water shortage, there is little water in the water supply tank 210, so although this is not particularly limited, the description will be given assuming that the heat generation amount of the warmth heater 600 is adjusted to be reduced.

[0076] When the refrigerator 1 starts operating, the heat generation amount adjustment function unit 114 starts monitoring the determination result of the water shortage determination function unit 112 (step S41). If the heat generation amount adjustment function unit 114 determines that there has been a change in the determination result of the water shortage determination function unit 112 (step S42), the heat generation amount adjustment function unit 114 determines whether the water shortage determination function unit 112 has determined that there is a water shortage (step S43).

[0077] When the heat generation amount adjustment function unit 114 determines that the water volume deficiency determination function unit 112 has determined that the water volume is insufficient, it sets the heat generation amount of the heat preservation heater 600 to the ``heat generation amount for water volume deficiency'' (step S44) and adjusts the amount of electricity flowing to the drive element 120 (step S45).

[0078] Here, the setting data for the "heat generation amount for water shortage" is set in advance and stored in the storage device 110b of the control device 110. The amount of current flowing through the drive element 120 corresponding to the "heat generation amount for water shortage" is calculated by dividing the "heat generation amount for water shortage" by the rated heat generation amount of the heater 600. When there is a water shortage, the water in the water supply tank 210 is likely to be nearly empty, or there will be so much water remaining that the automatic water supply mechanism 220 cannot pump it all up. For this reason, the value of the "heat generation amount for water shortage" can be set lower than when there is no water shortage, and it is still possible to prevent the water in the water supply tank 210 from freezing.

[0079] As described above, according to refrigerator 1 in embodiment 2, control device 110 has water shortage determination function unit 112 and determines whether the amount of water in water supply tank 210 is insufficient. At this time, sensor electrode 300 is installed so that the position of electrode lower end 330 corresponds to the position of the water level when water supply tank 210 is filled with enough water to fill ice tray 230. Therefore, water shortage determination function unit 112 can determine whether the amount of water is insufficient when there is not enough water remaining in water supply tank 210 to supply ice tray 230. Furthermore, heat generation amount adjustment function unit 114 in embodiment 2 can adjust the heat generation amount of warming heater 600 to a necessary and sufficient amount based on the water shortage determination by water shortage determination function unit 112, thereby reducing the power consumption of refrigerator 1.

[0080] Embodiment 3 In embodiment 3, an excessive water amount determination in water supply tank 210 performed by excess water amount determination function unit 113 of control device 110, as described in Fig. 10, will be described. Excess water amount determination function unit 113 determines whether the amount of water poured into water supply tank 210 is excessive. If an excessive amount of water is poured into water supply tank 210, there is a possibility that water will spill from water supply tank 210 into refrigerator compartment 10. There is also a possibility that the amount of water supplied to ice tray 230 will increase due to an increase in water pressure in water supply tank 210, for example.

[0081] 17 is a diagram showing the positional relationship between water supply tank 210 and sensor electrode 300 attached to peripheral member 16 in refrigerator 1 according to embodiment 3. In embodiment 3, in response to the excess water level determination by excess water determination function unit 113, the position of electrode upper end 310 of sensor electrode 300 is aligned to a position that is lower than the recommended upper water level when a user fills water supply tank 210 by an amount equivalent to the amount of water that fills ice tray 230. For this reason, as shown in FIG. 17 , peripheral member 16 has alignment shape portion 16b. Alignment shape portion 16b aligns sensor electrode 300 to prevent misalignment when attaching sensor electrode 300 to peripheral member 16 for installation.

[0082] For example, in refrigerator 1 in embodiment 1, sensor electrode 300 is installed so that electrode upper end 310 is positioned to coincide with the top of water supply tank 210. In this case, determining whether the water level in water supply tank 210 has exceeded the set recommended water level due to the user pouring water is determined by inferring from the capacitance value of sensor electrode 300 itself or by determining from the absolute value of the amount of capacitance decrease at the time of the first automatic water filling. This makes it difficult for control device 110 to make an accurate determination that takes into account fluctuations in the surrounding environment.

[0083] Therefore, in refrigerator 1 of embodiment 3, the position of electrode upper end 310 of sensor electrode 300 is adjusted to the position shown in Fig. 17. In this case, for example, when water is poured into water supply tank 210 to a water level exceeding the recommended upper water level, the water level movement at the first water supply after the user pours water into water supply tank 210 occurs above electrode upper end 310. Therefore, there is almost no decrease in the capacitance detected by sensor electrode 300 before and after the water supply.

[0084] On the other hand, when the amount of water poured by the user is below the recommended upper limit of the water level of the water supply tank 210, the water level changes below the upper end of the sensor electrode 300 from the first water pour, causing a drop in capacitance. Therefore, after the user pours water into the water supply tank 210, it can be determined whether the amount of water in the water supply tank 210 is excessive based on whether the capacitance included in the electrode signal related to detection by the sensor electrode 300 drops when water is first poured.

[0085] 18 is a diagram showing the flow of processing related to the determination of excess water volume in the water supply tank 210 according to embodiment 3. The determination of excess water volume is mainly performed by the excess water volume determination function unit 113 based on the result of the water level determination by the water level determination function unit 111, etc.

[0086] As described in the first embodiment, when a user pours water into the water supply tank 210, the capacitance related to the detection by the sensor electrode 300 increases. Therefore, the water level determination function unit 111 determines whether the user has poured water into the water supply tank 210 based on the capacitance (step S51). If the water level determination function unit 111 determines that the user has poured water into the water supply tank 210, it further determines whether the first water supply has occurred since the water supply tank 210 was poured (step S52). If the water level determination function unit 111 determines that the first water supply has occurred, it calculates the current descent amount (step S53).

[0087] The excess water amount determination function unit 113 determines whether the current capacitance decrease calculated by the water level determination function unit 111 is equal to or greater than a preset excess water amount determination threshold (step S54). If the excess water amount determination function unit 113 determines that the capacitance decrease is equal to or greater than the excess water amount determination threshold, it determines that the water level resulting from the water poured into the water supply tank 210 is equal to or less than the recommended upper water level of the water supply tank 210, and therefore determines that the water amount is not excessive (step S57).

[0088] On the other hand, if the excess water determination function unit 113 determines that the capacitance decrease is not equal to or greater than the excess water determination threshold, it determines that excessive water has been poured into the water supply tank 210 to a water level higher than the recommended upper limit water level, and therefore determines that the amount of water is excessive (step S55). The excess water determination function unit 113 then notifies or alerts the user that the amount of water is excessive (step S56). For example, the excess water determination function unit 113 may send a communication signal via the communication device 400 to display a notification on a display device (not shown) of an external device such as a smartphone, or send a display signal to the operation panel 500 to display a notification on the operation panel 500. Furthermore, the excess water determination function unit 113 may also control devices within the refrigerator 1.

[0089] 19 is a diagram illustrating the processing flow of the heat generation amount adjustment function unit 114 according to embodiment 3. The heat generation amount adjustment function unit 114 according to embodiment 3 adjusts the heat generation amount of the warmth heater 600 based on the determination result of the excess water amount determination function unit 113. Here, in the case of an excess water amount, there is a large amount of water in the water supply tank 210, so although this is not particularly limited, the description will be given assuming that the heat generation amount of the warmth heater 600 is adjusted to be increased.

[0090] When the refrigerator 1 starts operating, the heat generation amount adjustment function unit 114 starts monitoring the determination result of the excess water amount determination function unit 113 (step S61). If the heat generation amount adjustment function unit 114 determines that there has been a change in the determination result of the excess water amount determination function unit 113 (step S62), the heat generation amount adjustment function unit 114 determines whether the excess water amount determination function unit 113 has determined that the amount of water is excessive (step S63).

[0091] When the heat generation amount adjustment function unit 114 determines that the excess water amount determination function unit 113 has determined that the water amount is excessive, it sets the heat generation amount of the heat preservation heater 600 to the ``heat generation amount for excess water amount'' (step S64) and adjusts the amount of electricity flowing in the drive element 120 (step S65).

[0092] Here, the setting data for the "heat generation amount for excess water amount" is set in advance and stored in the memory device 110b or the like of the control device 110. The amount of current flowing through the drive element 120 corresponding to the "heat generation amount for excess water amount" is calculated by dividing the "heat generation amount for excess water amount" by the rated heat generation amount of the heater 600.

[0093] As described above, according to refrigerator 1 in embodiment 3, control device 110 has excess water determination function unit 113 and determines whether the amount of water in water supply tank 210 is excessive. At this time, sensor electrode 300 is installed so that the position of electrode upper end 310 corresponds to the position of the top of water supply tank 210. Therefore, excess water determination function unit 113 of control device 110 can determine whether the amount of water in water supply tank 210 is excessive. Furthermore, heat generation amount adjustment function unit 114 in embodiment 3 can adjust the heat generation amount of warming heater 600 to a necessary and sufficient amount based on the excess water amount determination by excess water determination function unit 113, thereby reducing the power consumption of refrigerator 1.

[0094] Embodiment 4 Fig. 20 is a diagram showing the shape of a sensor electrode 300 according to embodiment 4. As described in embodiment 1, the sensor electrode 300 has a shape having a width w that varies in the height direction. Therefore, as shown in Fig. 20, one of the two sides of the sensor electrode 300 in the height direction may be diagonal to change the width w.

[0095] Figure 21 is a diagram showing another shape of the sensor electrode 300 according to embodiment 4. As shown in Figure 21, the sensor electrode 300 may have a shape in which the width w of the electrode connection portion 320 is wide, such as a diamond shape. When the sensor electrode 300 is diamond-shaped, the water level determination function unit 111 determines that the water level in the water supply tank 210 is above the electrode connection portion 320 if the current amount of descent is greater than the previous amount of descent. On the other hand, the water level determination function unit 111 determines that the water level is below the electrode connection portion 320 if the current amount of descent is smaller than the previous amount of descent.

[0096] Embodiment 5. In the above-described embodiment 1, the reference drop amount is set as the previous drop amount, but this is not limited to this. The reference drop amount may be set based on the drop amount from the time before last. Although this increases the time until the water level determination is performed, the difference between the reference drop amount and the feedwater drop amount can be made larger.

[0097] 1 Refrigerator, 1a refrigerator body, 1b inner box, 1c outer box, 1d insulation material, 2 refrigerant circuit, 3 compressor, 4 heat sink, 5 expansion device, 6 cooler, 6a cooling temperature sensor, 6b heater, 10 refrigerator compartment, 11 refrigerator compartment door, 11a left door, 11b right door, 12 refrigerator compartment temperature sensor, 13 refrigerator compartment damper, 14 lighting equipment, 15 door switch, 16 peripheral components, 16a, 16b alignment shape portion, 20 switching compartment, 21 switching compartment door, 22 switching compartment temperature sensor, 23 switching compartment damper, 30 ice making compartment, 31 ice making compartment door, 32 ice making compartment temperature sensor, 33 ice making compartment damper, 40 freezer compartment, 41 freezer compartment door, 42 freezer compartment temperature sensor, 50 vegetable compartment, 51 vegetable compartment door, 52 Vegetable compartment temperature sensor, 53 Vegetable compartment damper, 60 Air passage, 61 Blower, 70 Partition, 71 Recess, 100 Control board, 110 Control device, 110a Control and arithmetic processing device, 110b Storage device, 111 Water level determination function unit, 112 Water volume shortage determination function unit, 113 Water volume excess determination function unit, 114 Heat generation amount adjustment function unit, 120 Drive element, 200 Automatic ice maker, 210 Water supply tank, 211 Tank side surface, 212 First stage portion, 213 Second stage portion, 220 Automatic water supply mechanism, 221 Water supply pump, 222 Water supply pipe, 223 Inlet, 224 Outlet, 225 Water supply port, 230 Ice tray, 240 Ice release mechanism, 250 Ice storage box, 300 Sensor electrode, 310 Electrode upper end portion, 320 Electrode connection part, 330 lower end of electrode, 340 upper electrode, 350 lower electrode, 400 communication device, 500 operation panel, 600 heat retention heater.

Claims

1. A refrigerator comprising: a water supply tank for storing water to be supplied to an ice tray; a sensor electrode having a shape with a width that varies in the height direction and for detecting capacitance in said water supply tank; and a control device for determining the water level in said water supply tank by comparing an amount of water supply descent, which is the difference in capacitance before and after water is supplied from said water supply tank to said ice tray, with a reference amount of water supply descent set for the amount of water supply descent.

2. The refrigerator according to claim 1, wherein the sensor electrode is installed along the side of the water supply tank with an upper end position corresponding to a position below the upper end of the water supply tank and a lower end position corresponding to a position above the inner bottom surface of the water supply tank, and has an upper electrode portion whose width narrows downward from the upper end of the electrode, and a lower electrode portion below the upper electrode portion whose width widens downward from an electrode connection portion which is a connection portion with the upper electrode portion, and wherein the control device, when determining that the amount of water supply descent is smaller than the reference descent amount, determines that the water level in the water supply tank is above the electrode connection portion, and when determining that the amount of water supply descent is greater than the reference descent amount, determines that the water level in the water supply tank is below the electrode connection portion.

3. The refrigerator according to claim 1 or 2, wherein the reference amount of decrease is the amount of decrease in capacitance when water was previously supplied from the water supply tank to the ice tray.

4. A refrigerator as claimed in any one of claims 1 to 3, wherein the sensor electrode is installed along a side of the water supply tank at a position where the lower end of the electrode is at a height corresponding to the water level when the water tank is filled with an amount of water to fill the ice tray, and the control device determines whether there is a shortage of water in the water supply tank based on the amount of descent of the water supply capacitance.

5. A refrigerator as claimed in any one of claims 1 to 4, wherein the sensor electrode is installed along a side of the water supply tank at a position where an upper end of the electrode is at a height corresponding to the water level when water is supplied from the upper limit water level of the water supply tank to an amount equivalent to one ice tray's worth of water, and the control device determines whether there is an excess amount of water in the water supply tank based on the amount of water supply descent of the capacitance.

6. A refrigerator as claimed in any one of claims 1 to 5, further comprising a heat retention heater that supplies heat to the water supply tank, wherein the control device adjusts the heat output of the heat retention heater based on the determined water level in the water supply tank.

7. The refrigerator according to claim 6, wherein said control device adjusts the heat generation amount of said warming heater to a preset heat generation amount for water shortage when it determines that the amount of water in said water supply tank is insufficient.

8. The refrigerator according to claim 6 or 7, wherein said control device adjusts the heat generation amount of said warming heater to a preset heat generation amount for an excess water amount when it determines that the amount of water in said water supply tank is excessive.

9. The refrigerator according to any one of claims 1 to 8, wherein the control device resets the reference lowering amount when water is poured into the water supply tank.

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