Space purification device

Abstract

The present invention comprises: a body case having a suction port and a blowout port; a blower unit that guides air from the suction port to the blowout port; an electrolytic cell that can be attached to and detached from the body case, the electrolytic cell mixing an electrolysis accelerator and water; an electrode unit that generates hypochlorous acid water from the electrolysis accelerator and the water mixed in the electrolytic cell; an electrostatic sensor in which the electrostatic capacitance changes on the basis of the amount of water within the electrolytic cell; and a determination unit (60) that determines the amount of water within the electrolytic cell on the basis of the electrostatic capacitance of the electrostatic sensor. The electrostatic sensor has a first electrode (18) and a second electrode (19) that increase in width downward in the vertical direction. The first electrode (18) and the second electrode (19) are provided at the same height and are configured to exhibit the same electrostatic capacitance characteristics when the amount of water within the electrolytic cell is the same.

Description

Space Purification Device

[0001] The present disclosure relates to a space purification device.

[0002] A dehumidifier capable of detecting the amount of water in a water reservoir that receives dehumidified water is known (see, for example, Patent Document 1). To detect the amount of water, a sensor that uses a change in capacitance is used.

[0003] Japanese Patent Application Laid-Open No. 2022-142012

[0004] In conventional technology, the amount of water in a container containing liquid can be detected by using a sensor whose capacitance changes when liquid is present. However, there is a demand for improving the detection accuracy of the amount of water detected by a sensor that uses the change in capacitance.

[0005] The present disclosure provides a space purification device that improves the detection accuracy of the amount of water detected by a sensor that uses changes in capacitance.

[0006] The space purification device according to the present disclosure includes a main body case having an inlet and an outlet, an air blower that guides air from the inlet to the outlet, an electrolytic cell detachably attached to the main body case for mixing an electrolysis accelerator and water, an electrode unit that produces hypochlorous acid water from the electrolysis accelerator and water mixed in the electrolytic cell, an electrostatic sensor whose capacitance changes based on the amount of water in the electrolytic cell, and a determination unit that determines the amount of water in the electrolytic cell based on the capacitance of the electrostatic sensor. The electrostatic sensor has first and second electrodes whose widths increase vertically downward, the first and second electrodes being disposed at the same height and configured to exhibit the same capacitance characteristics when the amount of water in the electrolytic cell is the same.

[0007] According to the present disclosure, it is possible to provide a space purification device that improves the detection accuracy of the amount of water detected by a sensor that uses changes in capacitance.

[0008] FIG. 1 is a perspective view of a space purification device according to an embodiment of the present disclosure. FIG. 2 is a perspective view of the space purification device according to the embodiment with the panel opened. FIG. 3 is a side cross-sectional view of the space purification device according to the embodiment. FIG. 4 is a front view showing an example of the shapes of the first electrode and the second electrode according to the embodiment. FIG. 5 is a schematic functional block diagram of a controller of a space purification device according to the embodiment. FIG. 6A is a diagram showing an example of a control procedure of a first acquisition process by a controller according to the embodiment in time series. FIG. 6B is a diagram showing an example of a control procedure of a second acquisition process by a controller according to the embodiment in time series. FIG. 7A is a diagram showing the relationship between the water volume and the voltage difference according to the embodiment. FIG. 7B is a diagram showing the relationship between the water volume and the voltage difference according to the embodiment and the comparative example. FIG. 8A is a diagram showing an example of a control procedure of a first acquisition process by a controller according to a modification of the present disclosure in time series. FIG. 8B is a diagram showing an example of a control procedure of a second acquisition process by a controller according to the modification in time series.

[0009] Hereinafter, embodiments of a space purification device according to the present disclosure will be described with reference to the drawings. Note that the following embodiments are presented as examples for explaining the present disclosure and are not intended to limit the present disclosure.

[0010] For example, the shapes, structures, materials, components, relative positional relationships, connection states, numerical values, mathematical formulas, and the content and order of each step in the method shown in the following embodiments are merely examples and may include content not described below. Furthermore, while geometric expressions such as "parallel" and "orthogonal" may be used, these expressions do not imply mathematical precision and include substantially permissible errors and deviations. Furthermore, expressions such as "simultaneous," "identical," and "the same" also include substantially permissible ranges.

[0011] In addition, in each drawing, substantially the same components are denoted by the same reference numerals, and redundant explanations are omitted or simplified. Furthermore, the dimensions of the components in each drawing are enlarged or reduced as appropriate to facilitate understanding. Furthermore, in each drawing, some components that are not important for explaining the embodiments are omitted.

[0012] (Embodiment) First, a space purification device D according to an embodiment of the present disclosure will be described.

[0013] The space purification device D is a device that is independently installed in a predetermined space and purifies the air present in the predetermined space in which the space purification device D is installed.

[0014] Fig. 1 is a perspective view of the space purification device D. Fig. 2 is a perspective view of the space purification device D in Fig. 1 with the panel 3 open.

[0015] As shown in FIGS. 1 and 2, the space purification device D includes a main body case 1.

[0016] The main body case 1 has a substantially box-like shape and is surrounded by a front surface 100 , a rear surface 101 , a first side surface 102 , a second side surface 103 , an upper surface 104 , and a lower surface 105 .

[0017] The direction from the front surface 100 to the rear surface 101 is the rear direction, and the direction from the rear surface 101 to the front surface 100 is the front direction. The direction from the first side surface 102 to the second side surface 103 is the left direction, and the direction from the second side surface 103 to the first side surface 102 is the right direction. Furthermore, the direction from the top surface 104 to the bottom surface 105 is the downward direction, and the direction from the bottom surface 105 to the top surface 104 is the upward direction.

[0018] Therefore, the front surface 100 and the rear surface 101 are arranged opposite each other in the front-to-rear direction, the first side surface 102 and the second side surface 103 are arranged opposite each other in the left-to-right direction, and the top surface 104 and the bottom surface 105 are arranged opposite each other in the up-to-down direction. The left-to-right direction can also be referred to as the horizontal direction, and the up-to-down direction can also be referred to as the vertical direction.

[0019] The main body case 1 has an air inlet 2 , an air outlet 6 , and a panel 3 .

[0020] The air inlets 2 are provided on both side surfaces (first side surface 102 and second side surface 103) of the main body case 1. The air inlets 2 are lattice-shaped openings that allow air from outside the main body case 1 to enter the main body case 1.

[0021] The air outlet 6 is provided on the top surface (upper surface 104) of the main body case 1. The air outlet 6 is an opening that can be opened and closed to blow air taken into the main body case 1 by the air inlet 2 out of the main body case 1. Note that in Figures 1 and 2, the air outlet 6 is in a closed state.

[0022] The panel 3 is provided on a first side surface 102, which is the right side surface when viewed from the front of the main body case 1. The panel 3 is an openable and closable cover, and is made primarily of plastic resin. One of the two air intake ports 2 is provided on the front side (forward side) of the main body case 1 in the panel 3. The inside of the panel 3 is the interior of the main body case 1.

[0023] An electrolytic cell 5 and a water storage tank 9 are provided inside the main body case 1 (see FIG. 2).

[0024] The electrolytic cell 5 has a box shape with an open top and is configured to store water. The electrolytic cell 5 is disposed at the bottom of the main body case 1 and is detachably attached to the main body case 1 by sliding horizontally relative to the main body case 1.

[0025] The electrolytic bath 5 mixes the electrolysis accelerator with water. Specifically, the electrolytic bath 5 mixes the electrolysis accelerator and water to be supplied to the electrolytic bath 5. In this embodiment, water is supplied to the electrolytic bath 5 by a water storage tank 9, but the user may directly supply water to the electrolytic bath 5. The electrolysis accelerator may be supplied to the electrolytic bath 5 by the user, or an electrolysis accelerator supply unit that supplies the electrolysis accelerator may be provided and the electrolysis accelerator may be supplied by controlling this electrolysis accelerator supply unit with the control unit 22 (see FIG. 3 ). Note that, in this case, dissolving the electrolysis accelerator in water is also considered to be mixing the electrolysis accelerator and water. By dissolving the electrolysis accelerator in water, water containing chloride ions is stored in the electrolytic bath 5. An example of an electrolysis accelerator is sodium chloride.

[0026] The water storage tank 9 is disposed above the electrolytic cell 5. The water storage tank 9 is detachably attached to the electrolytic cell 5 and the main body case 1. The water storage tank 9 is a hollow container capable of storing water and supplies water to the electrolytic cell 5. The water storage tank 9 is provided with a lid 10.

[0027] The lid 10 is attached to an opening located at the bottom of the water storage tank 9. An opening / closing portion is provided in the center of the lid 10, and when the opening / closing portion is opened, water in the water storage tank 9 is supplied to the electrolytic cell 5. Specifically, when the water storage tank 9 is attached to the electrolytic cell 5 with the opening of the water storage tank 9 facing downward, the opening / closing portion of the lid 10 opens. In other words, when the water storage tank 9 is filled with water and attached to the electrolytic cell 5, the opening / closing portion of the lid 10 opens, and water is supplied from the water storage tank 9 to the electrolytic cell 5. When water is supplied and the water level in the electrolytic cell 5 rises to the position of the lid 10, the opening / closing portion of the lid 10 is water-sealed. This stops the supply of water from the water storage tank 9, and water remains in the water storage tank 9. Whenever the water level in the electrolytic cell 5 drops, water from the water storage tank 9 is supplied to the electrolytic cell 5. In this way, the water level in the electrolytic cell 5 is maintained constant.

[0028] FIG. 3 is a side cross-sectional view of the space purification device D.

[0029] Inside the main body case 1, a blower section 12, an electrode section 14, and a purifier section 15 are provided.

[0030] The blower 12 is provided in the center of the main body case 1 and guides air from the air inlet 2 to the air outlet 6. The blower 12 is equipped with a fan. The fan is, for example, a sirocco fan, and rotates under the control of the control unit 22. As the fan rotates, air is sucked into the main body case 1 through the air inlet 2. The air sucked in through the air inlet 2 passes through the purification unit 15, which will be described later, and is then blown out from the air outlet 6.

[0031] The electrode unit 14 produces hypochlorous acid water from the electrolysis accelerator and water mixed in the electrolytic cell 5. The electrode unit 14 is equipped with an electrode member, and this electrode member is installed so as to be immersed in the water in the electrolytic cell 5. When electricity is applied to this electrode member, the electrode unit 14 electrochemically electrolyzes the water containing chloride ions in the electrolytic cell 5, i.e., the electrolyzed water, to produce hypochlorous acid water.

[0032] The electrode unit 14 generates hypochlorous acid water by repeating a cycle consisting of a current-carrying time during which current is applied to the electrode member for electrolysis and a non-current-carrying time after the current is stopped, i.e., a non-current-carrying time, multiple times. By providing a non-current-carrying time for the electrode member, the life of the electrode member can be extended. Note that if the current-carrying time is longer than the non-current-carrying time, a larger amount of hypochlorous acid is generated per cycle. Furthermore, if the non-current-carrying time is longer than the current-carrying time, the amount of hypochlorous acid generated per cycle can be reduced. Furthermore, if the amount of power during the current-carrying time is increased, more hypochlorous acid is generated.

[0033] The purifying unit 15 purifies the air by bringing the hypochlorous acid water produced in the electrolytic cell 5 into contact with the air drawn in through the suction port 2. The purifying unit 15 includes a filter.

[0034] The filter is a component that brings the hypochlorous acid water produced in the electrolytic cell 5 into contact with the air introduced into the main body case 1 by the blower 12. The filter is cylindrical and has a plurality of holes around its circumference that allow air to flow through. The filter is housed in the main body case 1 so that one end of the filter is immersed in the hypochlorous acid water produced in the electrolytic cell 5 to retain water, and is rotatable relative to the electrolytic cell 5 around a horizontally extending central axis. The filter is rotated by the drive unit, causing continuous contact between the hypochlorous acid water and the air. This enables air purification.

[0035] An air passage 13 is formed inside the main body case 1, extending from the air inlet 2 to the purification unit 15, the blower unit 12, and the outlet 6. When the fan of the blower unit 12 rotates, air is sucked in through the air inlet 2 and into the air passage 13, and is then blown out of the main body case 1 via the purification unit 15, the blower unit 12, and the outlet 6. This causes air containing the hypochlorous acid water in the electrolytic cell 5 to be released to the outside. In other words, the purification unit 15 purifies the space using the hypochlorous acid water produced in the electrolytic cell 5.

[0036] As shown in FIG. 3 , the main body case 1 also includes a partition wall 16 .

[0037] The partition wall 16 separates the electrostatic sensor space 31 in which the electrostatic sensor 17 is provided from the electrolytic cell space 32 in which the electrolytic cell 5 is provided. That is, the electrostatic sensor space 31 and the electrolytic cell space 32 exist within the main body case 1. In addition to the electrolytic cell 5, the water storage tank 9, the purifier 15, and the like are also disposed in the electrolytic cell space 32. That is, the water storage tank 9 is detachable from the electrolytic cell space 32. Meanwhile, the electrostatic sensor 17 and the controller 22 are disposed in the electrostatic sensor space 31.

[0038] Electrostatic sensor 17 is a sensor whose capacitance changes based on the amount of water in electrolytic bath 5. As shown in Fig. 3 , electrostatic sensor 17 is provided at a position facing electrolytic bath 5 across partition wall 16. Specifically, in this embodiment, electrostatic sensor 17 is provided at a position facing a side surface (a surface other than the top or bottom surface) of electrolytic bath 5 in the front-to-rear direction across partition wall 16. In more detail, the side surface of electrolytic bath 5 refers to the rear surface side of electrolytic bath 5 (the side facing rear surface 101 of main body casing 1, the rearward direction) and is the surface (side surface) of electrolytic bath 5 closest to electrostatic sensor 17.

[0039] Next, a specific configuration of the electrostatic sensor 17 will be described with reference to FIG.

[0040] Fig. 4 is a front view showing the configuration and arrangement of the electrostatic sensor 17. Fig. 4 shows the shape of the electrostatic sensor 17 when viewed from the front side toward the rear.

[0041] The electrostatic sensor 17 has two electrodes, a first electrode 18 and a second electrode 19, each of which has a capacitance. These capacitances change depending on whether or not a liquid (water) is present near the electrode. The capacitance also changes depending on the distance between the electrode and the liquid. Note that the water referred to in this embodiment includes water alone, a mixture of water and an electrolysis accelerator, hypochlorous acid water, and a mixture of hypochlorous acid water and an electrolysis accelerator. Each electrode is made of a metal, such as copper. However, the material of each electrode may be other metals, such as gold. Here, the horizontal length of each electrode is the width of each electrode, the vertical length of each electrode is the height of each electrode, and the front-to-back length of each electrode is the thickness of each electrode.

[0042] The first electrode 18 is disposed to the left of the second electrode 19. That is, the second electrode 19 is disposed to the right of the first electrode 18. The arrangement of the first electrode 18 and the second electrode 19 may be reversed. Furthermore, each of the first electrode 18 and the second electrode 19 has a shape that increases in width vertically downward. Furthermore, the first electrode 18 and the second electrode 19 are provided at the same height and have a shape that exhibits the same capacitance characteristics when the amount of water in the electrolytic cell 5 is the same. In other words, the first electrode 18 and the second electrode 19 are configured to exhibit the same capacitance characteristics when the water level in the electrolytic cell 5 is the same.

[0043] FIG. 4 shows an example of the shape of the first electrode 18 and the second electrode 19. In this embodiment, the first electrode 18 and the second electrode 19 are triangular. In this embodiment, the first electrode 18 and the second electrode 19 are triangular in shape, with the width increasing vertically downward. The first electrode 18 and the second electrode 19 may have other shapes. For example, the first electrode 18 and the second electrode 19 may be L-shaped. The first electrode 18 and the second electrode 19 may be semicircular, trapezoidal, circular, elliptical, or the like. That is, the first electrode 18 and the second electrode 19 may have any shape as long as they are provided at the same height and exhibit the same capacitance characteristics when the water level in the electrolytic cell 5 is the same.

[0044] In this embodiment, the first electrode 18 and the second electrode 19 have bilaterally symmetrical shapes so that they exhibit the same capacitance characteristics when the water level in the electrolytic cell 5 is the same. Note that the first electrode 18 and the second electrode 19 may have the same shape.

[0045] Next, the capacitance characteristics will be described in detail below.

[0046] The water level in the electrolytic cell 5 changes depending on the amount of water (amount of liquid) in the electrolytic cell 5. Specifically, the greater the amount of water in the electrolytic cell 5, the higher the water level in the electrolytic cell 5. When the water level in the electrolytic cell 5 changes, the proportion of water present in the position opposite the first electrode 18 changes. In other words, when the water level in the electrolytic cell 5 changes, the size of the area of ​​the first electrode 18 opposite to which water exists changes. Note that the electrode area (hereinafter referred to as electrode area) here refers to the area of ​​the front side of the first electrode 18 (the front side, front surface 100 side of the main body case 1) where water exists in the opposite position.

[0047] When the electrode area of ​​the first electrode 18 facing the water changes, the capacitance of the first electrode 18 changes. Specifically, the capacitance of the first electrode 18 increases as the amount of water in the electrolytic cell 5 increases. That is, the capacitance of the first electrode 18 increases as the water level in the electrolytic cell 5 increases.

[0048] The same applies to second electrode 19. When the water level in electrolytic cell 5 changes, the proportion of water present in the position opposite second electrode 19 changes. In other words, when the water level in electrolytic cell 5 changes, the size of the area of ​​second electrode 19 opposite to which water exists changes. Note that the electrode area (electrode area) referred to here is the area of ​​second electrode 19 on the front side (the front surface 100 side of main body case 1, the forward side) where water exists in the opposite position.

[0049] When the electrode area of ​​the second electrode 19 opposite to which water is present changes, the capacitance of the second electrode 19 changes. Specifically, the capacitance of the second electrode 19 increases as the amount of water in the electrolytic cell 5 increases. That is, the capacitance of the second electrode 19 increases as the water level in the electrolytic cell 5 increases.

[0050] As described above, when the amount of water in the electrolytic cell 5 is the same, the first electrode 18 and the second electrode 19 need to exhibit the same capacitance characteristics. Therefore, the first electrode 18 and the second electrode 19 are provided at the same height and have bilaterally symmetrical or identical shapes. Furthermore, the front side surfaces of the first electrode 18 and the second electrode 19 are provided in positions opposite the rear side surface of the electrolytic cell 5 with the partition wall 16 in between.

[0051] Here, the amount of water in the electrolytic cell 5 will be described. In the space purification device D, hypochlorous acid is generated by applying a voltage to the electrode unit 14. When applying a voltage to the electrode unit 14, it is preferable that all of the electrode members of the electrode unit 14 are immersed in water. If current is applied when at least a portion of the electrode members is not immersed in water, deterioration of the non-immersed portions of the electrode members will be accelerated.

[0052] The non-immersed water volume is the volume of water in the electrolytic cell 5 when at least a portion of the electrode members is not immersed in water. In other words, the non-immersed water volume in the electrolytic cell 5 when at least a portion of the electrode members is not immersed in water can also be said to be the volume of water in a drought state where the electrolytic cell 5 is short of water.

[0053] The water level when the water volume in the drought state is the largest is substantially the same as the height of the highest point of the electrode members. Here, the water level in the electrolytic cell 5 corresponding to the height of the highest point of the electrode members is referred to as the drought water level. The amount of water in the electrolytic cell 5 when water is present at the drought water level is referred to as the drought water volume. In other words, the drought water volume can be said to be the amount of water just before the electrode members are exposed to the water surface, and is not a state in which the water in the electrolytic cell 5 has been completely depleted.

[0054] Here, it is important to know whether the water in the electrolytic cell 5 is at the drought level or not. If the water in the electrolytic cell 5 is below the drought level, it is not preferable to energize the electrode unit 14, as described above.

[0055] The first electrode 18 is provided at a position opposite, across the partition wall 16, to the drought level of the water in the electrolytic cell 5, i.e., the water level at which the electrolytic cell 5 is in a drought state where there is a shortage of water. As shown in Fig. 4, the first electrode 18 is preferably positioned so that a portion of the first electrode 18 with a relatively large width is located at a position opposite the drought level.

[0056] The same applies to the second electrode 19. The second electrode 19 is provided at a position opposite, across the partition wall 16, the water level at which the water in the electrolytic cell 5 is at the drought level, i.e., the water level at which the electrolytic cell 5 is in a drought state where there is a shortage of water. As shown in Fig. 4, the second electrode 19 is preferably positioned so that a portion of the second electrode 19 with a relatively large width is located at a position opposite the drought level.

[0057] The reason why it is preferable to position the first electrode 18 and the second electrode 19 so that a relatively wide portion of the first electrode 18 and the second electrode 19 exists at a position opposite the drought water level will be described later.

[0058] 3, the control unit 22 controls the space purification device D. The specific control content will be described later.

[0059] The space purification device D includes a notification unit 8. The notification unit 8 is provided, for example, on the top surface of the space purification device D, and notifies the user of water volume information. In this embodiment, the water volume information refers to the water volume information of the electrolytic bath 5. An example of the notification unit 8 is a display LED, which displays the water volume information. The water volume information displayed by the notification unit 8 is controlled by the control unit 22. The notification unit 8 may also notify the user by sound, such as a buzzer.

[0060] Furthermore, the notification unit 8 does not have to be provided on the top surface of the space purification device D. For example, a mobile terminal may have the notification unit, and by enabling wireless communication between the mobile terminal and the control unit 22, the mobile terminal may notify the notification unit of the water volume information transmitted via wireless communication. In other words, the notification unit may be a touch panel or a display panel such as a liquid crystal panel or an organic EL panel.

[0061] Here, hypochlorous acid generated in the electrolytic cell 5 volatilizes in the electrolytic cell space 32. The volatilized hypochlorous acid can corrode the first electrode 18 and the second electrode 19 of the electrostatic sensor 17, as well as the circuit board used to realize the functions of the control unit 22. For this reason, the partition 16 is provided to prevent the volatilized hypochlorous acid from entering the electrostatic sensor space 31. In other words, the partition 16 separates the electrostatic sensor space 31 from the electrolytic cell space 32, preventing the volatilized hypochlorous acid from passing between them.

[0062] Next, each function of the control unit 22 according to the embodiment of the present disclosure will be described with reference to FIG.

[0063] FIG. 5 is a schematic functional block diagram of the control unit 22 and its peripheral parts.

[0064] Each functional block of the control unit 22 can be realized as hardware by elements and mechanical devices such as a computer's CPU (Central Processing Unit), and as software by a computer program, etc., but here, it is a functional block realized by the cooperation of these. Therefore, these functional blocks can be realized in various forms by combining hardware and software. In this embodiment, the control unit 22 is composed of a circuit board and is realized by combining each element on the circuit board and a computer program, etc.

[0065] The control unit 22 includes a first capacitor 44, a first ground 43, a first voltage application unit 40, a first connection unit 41, a second connection unit 42, a second capacitor 54, a second ground 53, a second voltage application unit 50, a third connection unit 51, a fourth connection unit 52, and a judgment unit 60.

[0066] The first capacitor 44 is, for example, a capacitor configured on a circuit board. The capacitance of the first capacitor 44 does not change depending on the amount of water in the electrolytic bath 5. In other words, the capacitance of the first electrode 18 changes depending on the amount of water in the electrolytic bath 5, but the capacitance of the first capacitor 44 does not change. In this embodiment, the control unit 22 is configured to include the first capacitor 44, but the control unit 22 may not be configured to include the first capacitor 44. For example, the first capacitor 44 may be provided on a circuit board different from that of the control unit 22, and the circuit board on which the first capacitor 44 is provided may be connected to the control unit 22.

[0067] The first voltage application unit 40 is generally called a power supply circuit and generates a voltage to be applied. An external power source is supplied to the space purification device D, for example, via a residential outlet, and the first voltage application unit 40 generates a voltage to be applied from the external power source. In this embodiment, the first voltage application unit 40 generates a DC voltage VDD as the voltage to be applied. The first voltage application unit 40 is, for example, a regulator.

[0068] By connecting the first voltage application unit 40 and the first electrode 18, a DC voltage VDD is applied to the first electrode 18, and an amount of charge corresponding to the capacitance of the first electrode 18 is charged. Furthermore, by connecting the first voltage application unit 40 and the first capacitor 44, a DC voltage VDD is applied to the first capacitor 44, and an amount of charge corresponding to the capacitance of the first capacitor 44 is charged.

[0069] The first ground 43 is generally called a ground (GND) and is a reference for voltage within the circuit. The first ground 43 can discharge electric charges from the connected device. That is, when the first ground 43 is connected to the first electrode 18, the electric charge stored in the first electrode 18 is discharged. Furthermore, when the first ground 43 is connected to the first capacitor 44, the electric charge stored in the first capacitor 44 is discharged.

[0070] The first connection unit 41 switches between a first mode in which the first electrode 18 is connected to the first voltage application unit 40 and a second mode in which the first electrode 18 is connected to the second connection unit 42. The first connection unit 41 may further have a third mode in which the first electrode 18 is connected to a first ground 43. The first connection unit 41 may further have a fourth mode in which the first electrode 18 is not connected to anything.

[0071] An example of the first connection unit 41 is a relay component. The first connection unit 41 may be configured with a component such as a transistor. The mode switching control by the first connection unit 41 is performed by a first voltage acquisition unit 61 of the determination unit 60.

[0072] The second connection unit 42 switches between a fifth mode in which the first capacitor 44 is connected to the first ground 43 and a sixth mode in which the first capacitor 44 is connected to the first connection unit 41. The second connection unit 42 may further include a seventh mode in which the first capacitor 44 is connected to the first voltage application unit 40. The second connection unit 42 may further include an eighth mode in which the first capacitor 44 is not connected to anything.

[0073] An example of the second connection unit 42 is a relay component. The second connection unit 42 may be configured with a component such as a transistor. The mode switching control by the second connection unit 42 is performed by the first voltage acquisition unit 61 of the determination unit 60.

[0074] The second capacitor 54 is, for example, a capacitor configured on a circuit board. The capacitance of the second capacitor 54 does not change depending on the amount of water in the electrolytic bath 5. In other words, the capacitance of the second electrode 19 changes depending on the amount of water in the electrolytic bath 5, but the capacitance of the second capacitor 54 does not change. In this embodiment, the control unit 22 is configured to include the second capacitor 54, but the control unit 22 may not be configured to include the second capacitor 54. For example, the second capacitor 54 may be provided on a circuit board different from that of the control unit 22, and the circuit board on which the second capacitor 54 is provided may be connected to the control unit 22. The first capacitor 44 and the second capacitor 54 are capacitors with the same capacitance.

[0075] The second voltage application unit 50 is generally called a power supply circuit and generates a voltage to be applied. An external power source is supplied to the space purification device D, for example, via a residential outlet, and the second voltage application unit 50 generates a voltage to be applied from the external power source. In this embodiment, the second voltage application unit 50 generates a DC voltage VDD as the voltage to be applied. The second voltage application unit 50 is, for example, a regulator.

[0076] By connecting the second voltage application unit 50 and the second electrode 19, a DC voltage VDD is applied to the second electrode 19, and an amount of charge corresponding to the capacitance of the second electrode 19 is charged. Furthermore, by connecting the second voltage application unit 50 and the second capacitor 54, a DC voltage VDD is applied to the second capacitor 54, and an amount of charge corresponding to the capacitance of the second capacitor 54 is charged.

[0077] The first voltage application section 40 and the second voltage application section 50 may be a common section. In other words, the first voltage application section 40 may also be used as the second voltage application section 50.

[0078] The second ground 53 is generally called ground (GND) and is a reference for voltage within the circuit. The second ground 53 can discharge electric charges from the connected device. That is, when the second ground 53 is connected to the second electrode 19, the electric charge stored in the second electrode 19 is discharged. Furthermore, when the second ground 53 is connected to the second capacitor 54, the electric charge stored in the second capacitor 54 is discharged.

[0079] The first ground 43 and the second ground 53 may be common to each other. In other words, the first ground 43 may also be used as the second ground 53.

[0080] The third connection unit 51 switches between a ninth mode in which the second capacitor 54 is connected to the second voltage application unit 50 and a tenth mode in which the second capacitor 54 is connected to the fourth connection unit 52. The third connection unit 51 may further include an eleventh mode in which the second capacitor 54 is connected to the second ground 53. The third connection unit 51 may further include a twelfth mode in which the second capacitor 54 is not connected to anything.

[0081] An example of the third connection unit 51 is a relay component. The third connection unit 51 may be configured with a component such as a transistor. The mode switching control by the third connection unit 51 is performed by the second voltage acquisition unit 62 of the determination unit 60.

[0082] The fourth connection portion 52 switches between a thirteenth mode in which the second electrode 19 is connected to the second ground 53 and a fourteenth mode in which the second electrode 19 is connected to the third connection portion 51. The fourth connection portion 52 may further include a fifteenth mode in which the second electrode 19 is connected to the second voltage application portion 50. The fourth connection portion 52 may further include a sixteenth mode in which the second electrode 19 is not connected to anything.

[0083] An example of the fourth connection unit 52 is a relay component. The fourth connection unit 52 may be configured with a component such as a transistor. The mode switching control by the fourth connection unit 52 is performed by the second voltage acquisition unit 62 of the determination unit 60.

[0084] The determination unit 60 determines the amount of water in the electrolytic bath 5 based on the capacitance of the electrostatic sensor 17. As described above, when the amount of water in the electrolytic bath 5 changes, the capacitance of the electrostatic sensor 17 (first electrode 18 and second electrode 19) changes.

[0085] The determination unit 60 includes a first voltage acquisition unit 61 , a second voltage acquisition unit 62 , a voltage difference calculation unit 63 , a water volume determination unit 64 , and a storage unit 65 .

[0086] The first voltage acquisition unit 61 executes a first acquisition process in which it applies a voltage to the first electrode 18 to charge the first electrode 18, stops the voltage application, and acquires a first voltage, which is the voltage across the first electrode 18 and the first capacitor 44 when the first electrode 18 and the first capacitor 44 are connected. Details of the first acquisition process will be described later.

[0087] The second voltage acquisition unit 62 executes a second acquisition process in which it applies a voltage to the second capacitor 54 to charge the second capacitor 54, stops the voltage application, and acquires a second voltage, which is the voltage across the second electrode 19 and the second capacitor 54 when the second electrode 19 and the second capacitor 54 are connected. Details of the second acquisition process will be described later.

[0088] The determination unit 60 performs the first acquisition process and the second acquisition process at the same time.

[0089] The voltage difference calculation unit 63 calculates a first voltage difference, which is the difference between the first voltage and the second voltage.

[0090] The water volume determination unit 64 determines the water volume in the electrolytic bath 5 based on the first voltage difference calculated by the voltage difference calculation unit 63. Specifically, if the first voltage difference is equal to or less than the drought threshold, the water volume determination unit 64 determines that the water volume in the electrolytic bath 5 is in a drought state, where water is insufficient. Note that the water volume determination unit 64 may also determine that the water volume in the electrolytic bath 5 is in a drought state, where water is insufficient, if the first voltage difference is smaller than the drought threshold. The drought threshold is stored, for example, in a memory unit 65 included in the control unit 22 (determination unit 60). The memory unit 65 is a so-called memory.

[0091] The drought threshold is a threshold for determining whether or not there is a water volume in the electrolytic cell 5 that is greater than the drought water volume, which is the amount of water in a drought state where the electrolytic cell 5 is short of water. The drought threshold is a value that is determined in advance, for example, by experiments or the like, and can be set arbitrarily. How the drought threshold is determined by experiments or the like will be described in detail later.

[0092] When it is determined that the amount of water in the electrolytic bath 5 is a drought amount, the water amount determination unit 64 notifies the user of the water amount information via the notification unit 8. That is, the notification unit 8 notifies the user of the water amount information based on the water amount determination made by the determination unit 60 (water amount determination unit 64). Specifically, when it is determined that the amount of water in the electrolytic bath 5 is a drought amount, the water amount determination unit 64 notifies the user of the drought amount of water in the electrolytic bath 5 via the notification unit 8. The notification unit 8 may notify the user of the drought amount of water in the electrolytic bath 5 by, for example, lighting an LED. The notification unit 8 may also notify the user of the drought amount of water in the electrolytic bath 5 by sounding a buzzer or the like.

[0093] Next, a detailed flow of control executed by the control unit 22 will be described with reference to the timing charts of FIGS. 6A and 6B.

[0094] 6A and 6B are diagrams showing an example of a control procedure by the control unit 22 in time series.

[0095] First, the first acquisition process will be described with reference to the timing chart of Fig. 6A. Here, the flow of the first acquisition process will be described.

[0096] It is preferable that the first voltage acquisition unit 61 sets the first connection unit 41 to the third mode and the second connection unit 42 to the fifth mode before performing the first acquisition process, that is, before timing T1. This allows the remaining charge in the first electrode 18 and the first capacitor 44 to be eliminated. At this time, the first electrode voltage, which is the voltage of the first electrode 18, and the first capacitor voltage, which is the voltage of the first capacitor 44, both become zero.

[0097] At timing T1, the first voltage acquisition unit 61 sets the first connection unit 41 to the first mode and the second connection unit 42 to the fifth mode. As a result, the first electrode 18 is charged and the first capacitor 44 is discharged. In other words, the first electrode voltage becomes VDD and the first capacitor voltage becomes zero.

[0098] Here, timing T1 is the timing for starting the first acquisition process and can be set arbitrarily. For example, the first voltage acquisition unit 61 may start timing T1 at a predetermined time interval, at a preset time, or when a receiving unit that receives a request to start from a user is provided and the receiving unit receives the request to start.

[0099] As shown in FIG. 6A , next, at timing T2, the first voltage acquisition unit 61 sets the first connection unit 41 to the second mode and the second connection unit 42 to the sixth mode. The first voltage acquisition unit 61 may set the first connection unit 41 to the second mode via the fourth mode. The first voltage acquisition unit 61 may also set the second connection unit 42 to the sixth mode via the eighth mode. This stops the application of voltage to the first electrode 18, stops the discharge of the first capacitor 44, and connects the first electrode 18 and the first capacitor 44. At this time, the first electrode 18 and the first capacitor 44 are connected in parallel. Because the first electrode 18 and the first capacitor 44 are connected in parallel, the first electrode voltage and the first capacitor voltage tend to the same voltage. The first electrode voltage and the first capacitor voltage at this time are referred to as the first voltage. The first voltage is determined by the amount of charge stored in the first electrode 18 before timing T2, the capacitance of the first electrode 18, and the capacitance of the first capacitor 44.

[0100] The time from timing T1 to timing T2 can be set arbitrarily, but at least the time until the charging of the first electrode 18 is completed is required. The charging of the first electrode 18 is completed when the amount of charge on the first electrode 18 does not increase any further even if a voltage is applied. The time until the charging of the first electrode 18 is completed can be measured in advance by experiment or the like, and the time from timing T1 to timing T2 can be set to a time equal to or greater than the maximum time required for charging the first electrode 18.

[0101] Next, the first voltage acquisition unit 61 acquires the first voltage at timing T3. Note that the time from timing T2 to timing T3 can be set arbitrarily, but at least the time until the first voltage reaches a stable voltage value is required. The time until the first voltage reaches a stable voltage value may be measured in advance through an experiment or the like, and a time equal to or greater than the maximum time until the first voltage reaches a stable voltage value may be set as the time from timing T2 to timing T3.

[0102] This concludes the description of the flow of the first acquisition process.

[0103] Next, the second acquisition process will be described with reference to the timing chart of Fig. 6B. Here, the flow of the second acquisition process will be described.

[0104] It is preferable that the second voltage acquisition unit 62 sets the fourth connection unit 52 to the thirteenth mode and the third connection unit 51 to the eleventh mode before performing the second acquisition process, that is, before timing T11. This makes it possible to eliminate any remaining charge in the second electrode 19 and the second capacitor 54. At this time, the second electrode voltage, which is the voltage of the second electrode 19, and the second capacitor voltage, which is the voltage of the second capacitor 54, both become zero.

[0105] At timing T11, the second voltage acquisition unit 62 sets the fourth connection unit 52 to the thirteenth mode and the third connection unit 51 to the ninth mode, thereby charging the second capacitor 54 and discharging the second electrode 19. In other words, the second capacitor voltage becomes VDD and the second electrode voltage becomes zero.

[0106] Here, timing T11 is the timing for starting the second acquisition process and can be set arbitrarily. For example, the second voltage acquisition unit 62 may start timing T11 at a predetermined time interval, at a preset time, or when a receiving unit that receives a request to start from a user is provided and the receiving unit receives the request to start.

[0107] As shown in FIG. 6B , next, at timing T12, the second voltage acquisition unit 62 sets the fourth connection unit 52 to the 14th mode and the third connection unit 51 to the 10th mode. The second voltage acquisition unit 62 may set the fourth connection unit 52 to the 14th mode via the 16th mode. The second voltage acquisition unit 62 may also set the third connection unit 51 to the 10th mode via the 12th mode. This stops the application of voltage to the second capacitor 54, stops the discharge of the second electrode 19, and connects the second electrode 19 and the second capacitor 54. At this time, the second electrode 19 and the second capacitor 54 are connected in parallel. Because the second electrode 19 and the second capacitor 54 are connected in parallel, the second electrode voltage and the second capacitor voltage tend to the same voltage. The second electrode voltage and the second capacitor voltage at this time are referred to as the second voltage. The second voltage is determined by the amount of charge stored in the second capacitor 54 before timing T12, the capacitance of the second electrode 19, and the capacitance of the second capacitor 54.

[0108] The time from timing T11 to timing T12 can be set arbitrarily, but at least the time required is until the charging of the second capacitor 54 is completed. The charging of the second capacitor is completed when the amount of charge in the second capacitor 54 does not increase any further even if a voltage is applied. The time until the charging of the second capacitor 54 is completed can be measured in advance by experiment or the like, and the time from timing T11 to timing T12 can be set to a time equal to or greater than the maximum time required to charge the second capacitor 54.

[0109] Next, the second voltage acquisition unit 62 acquires the second voltage at timing T13. Note that the time from timing T12 to timing T13 can be set arbitrarily, but at least the time until the second voltage reaches a stable voltage value is required. The time until the second voltage reaches a stable voltage value may be measured in advance through an experiment or the like, and the time from timing T12 to timing T13 may be set to a time equal to or greater than the maximum time until the second voltage reaches a stable voltage value.

[0110] This concludes the description of the flow of the second acquisition process.

[0111] After the first acquisition process and the second acquisition process are completed, the voltage difference calculation unit 63 calculates a first voltage difference, which is the difference between the first voltage and the second voltage. Specifically, the voltage difference calculation unit 63 calculates the first voltage difference by subtracting the second voltage from the first voltage. Note that the greater the amount of water in the electrolytic bath 5, the greater the first voltage difference. In other words, as more water in the electrolytic bath 5 is consumed by the purifier 15 and the like and the amount of water in the electrolytic bath 5 approaches the drought water level, the smaller the first voltage difference. In other words, as more water in the electrolytic bath 5 is consumed by the purifier 15 and the like and the water level in the electrolytic bath 5 approaches the drought water level, the smaller the first voltage difference.

[0112] Next, if the first voltage difference is equal to or less than the drought threshold, the water volume determination unit 64 determines that the water volume in the electrolytic cell 5 corresponds to a drought state where the electrolytic cell 5 is short of water. As described above, the drought threshold is used to determine whether the electrolytic cell 5 contains a water volume greater than the drought water volume, which is the amount of water in the drought state where the electrolytic cell 5 is short of water. The drought threshold is a value determined in advance through experiments or the like and can be set arbitrarily. For example, the first voltage difference when the drought water volume is present in the electrolytic cell 5 may be calculated in advance through experiments or the like, and the calculated value may be stored in the memory unit 65 as the drought threshold. This makes it possible to determine that the water volume in the electrolytic cell 5 corresponds to a drought state where the electrolytic cell 5 is short of water. Since the water volume in the drought state can be determined in this way, the supply of electricity to the electrode unit 14 during the drought state can be suppressed, thereby suppressing deterioration of the electrode unit 14.

[0113] When it is determined that the water volume in the electrolytic bath 5 is at a drought level, the water volume determination unit 64 notifies the user via the notification unit 8 that the water volume in the electrolytic bath 5 is at a drought level. This allows the user to understand that the water volume in the electrolytic bath 5 is at a drought level. This allows the user to understand that action is required, such as refilling the water storage tank 9 with water. Refilling the water storage tank 9 with water allows current to be applied to the electrode unit 14, enabling continuous production of hypochlorous acid.

[0114] Here, it is preferable that the first acquisition process and the second acquisition process are performed at the same timing. Specifically, it is preferable that at least timing T3 and timing T13 are performed at the same timing. It is also preferable that timing T1 and timing T11 are performed at the same timing. It is also preferable that timing T2 and timing T12 are performed at the same timing.

[0115] The reason for this will be explained. A stray capacitance exists between the first electrode 18 and the ground (first ground 43) of the control unit 22, and this stray capacitance changes over time. Furthermore, a stray capacitance also exists between the second electrode 19 and the ground (second ground 53) of the control unit 22. The value of this stray capacitance also changes over time. This is because the temperature, humidity, and surrounding electric field conditions change over time. In other words, even if the amount of water in the electrolytic cell 5 is the same, the first voltage and the second voltage will fluctuate depending on the timing. Therefore, by performing the first acquisition process and the second acquisition process at the same time as in the present disclosure, the influence of changes in stray capacitance can be suppressed. In other words, the water volume can be determined with high accuracy.

[0116] Specifically, the water volume determination unit 64 calculates the difference (first voltage difference) between the first voltage and the second voltage obtained at the same time when the same stray capacitance exists. Because the first voltage and the second voltage are obtained at the same time, the calculation of the first voltage difference cancels out the voltage change corresponding to the stray capacitance that is the same between the first voltage and the second voltage (first electrode 18 and second electrode 19). In other words, the change in stray capacitance (noise) that changes over time is prevented from affecting the value of the first voltage difference.

[0117] On the other hand, if the first acquisition process and the second acquisition process are performed at different times, changes in stray capacitance (noise) that change over time are likely to affect the value of the first voltage difference, which will deteriorate the accuracy of determining the water volume and reduce the accuracy of determining whether the water volume in the electrolytic cell 5 is in a drought state.

[0118] In this way, in the present disclosure, the first acquisition process and the second acquisition process are performed at the same time, thereby improving the accuracy of determining the water volume, and improving the accuracy of determining whether the water volume in the electrolytic cell 5 is in a drought state.

[0119] Here, the transition of the first voltage difference with respect to the amount of water in the electrolytic cell 5 will be described with reference to FIGS. 7A and 7B.

[0120] 7A and 7B are diagrams showing the relationship between the amount of water (water level) in the electrolytic cell 5 and the first voltage difference corresponding to the amount of water.

[0121] FIG. 7A illustrates the relationship between the first electrode 18 and the second electrode 19 in the present embodiment (triangular shape). The horizontal axis represents the first voltage value (voltage difference value), and the vertical axis represents the water volume (water level) in the electrolytic bath 5. As shown in FIG. 7A , the smaller the water volume in the electrolytic bath 5, the smaller the first voltage difference. As described above, whether the amount of water in the electrolytic bath 5 is equal to or greater than the drought water volume is related to whether the electrode unit 14 can be energized. Therefore, it is important to accurately determine whether the amount of water in the electrolytic bath 5 is equal to or greater than the drought water volume. If this determination is not accurate, the electrode unit 14 may be energized when the amount of water in the electrolytic bath 5 is less than the drought water volume, potentially accelerating deterioration of the electrode unit 14. Furthermore, if this determination is not accurate, the user may need to refill the water tank 9 more frequently, potentially reducing usability.

[0122] 7B is a diagram showing the relationship between the amount of water in electrolytic cell 5 and the first voltage difference when first electrode 18 and second electrode 19 have a (triangular) shape in the present embodiment, and the relationship between the amount of water in electrolytic cell 5 and the first voltage difference when, unlike the present embodiment, first electrode 18 and second electrode 19 have a rectangular shape whose width does not increase when the electrode is turned vertically downward (comparative example). In Fig. 7B, the relationship when each electrode has a triangular shape is shown by a solid line, and the relationship when each electrode has a rectangular shape (comparative example) is shown by a dashed line.

[0123] When each electrode is rectangular, the relationship between the water volume and the first voltage difference is proportional. That is, when the water volume decreases by water volume A, the first voltage difference decreases by water volume B in proportion to the water volume A.

[0124] However, when the electrodes are triangular, as in the present embodiment, the relationship between the water volume and the first voltage difference is not proportional. In particular, at water volumes near the drought level, a decrease in water volume by volume A causes a greater decrease in the first voltage difference than volume B. In other words, at water volumes near the drought level, the present embodiment exhibits a greater decrease in the first voltage difference relative to a decrease in water volume than the comparative example. However, to achieve such characteristics, as described above, it is preferable to position the first electrode 18 and the second electrode 19 so that the relatively wide portions of the first electrode 18 and the second electrode 19 are located at positions facing the drought level.

[0125] This will be explained in more detail. As mentioned above, when the water level (amount of water) in the electrolytic cell 5 changes, the proportion of water present at the position opposite the first electrode 18 changes. In other words, when the amount of water in the electrolytic cell 5 changes, the electrode area of ​​the first electrode 18 where water is present at the opposite position changes. When the electrode area of ​​the first electrode 18 where water is present at the opposite position changes, the capacitance of the first electrode 18 changes. The same is true for the second electrode 19.

[0126] Here, when the electrode shape is rectangular, the amount of change in the amount of water in electrolytic cell 5 is proportional to the amount of change in the electrode area of ​​first electrode 18, where water is present at a position opposite to first electrode 18. The same is true for second electrode 19. Therefore, the amount of water and the first voltage difference have a proportional relationship, as shown by the dashed line in FIG. 7B .

[0127] On the other hand, in this embodiment, the amount of change in the amount of water in the electrolytic cell 5 is not proportional to the amount of change in the electrode area of ​​the first electrode 18 opposite to which water is present. In this embodiment, the amount of change in the electrode area when the amount of water in the electrolytic cell 5 changes by a predetermined amount is larger when the water level in the electrolytic cell 5 is low than when the water level in the electrolytic cell 5 is high. The same is true for the second electrode 19. As a result, the amount of change in the first voltage difference is larger when the water level in the electrolytic cell 5 changes by a predetermined amount when the water level is low (water volume is small) than when the water volume changes by a predetermined amount when the water level in the electrolytic cell 5 is high (water volume is large).

[0128] In this embodiment, first electrode 18 and second electrode 19 are arranged so that a relatively wide portion of first electrode 18 and second electrode 19 exists at a position facing the drought water level. As a result, as shown in Fig. 7B, when the water volume in electrolytic cell 5 is close to the drought water level (drought water volume), the amount of change in the first voltage difference when the water volume changes by a predetermined amount is larger than in the comparative example. In other words, because the amount of change in the first voltage value in response to a change in water volume close to the drought water volume is large, it is possible to accurately determine whether the water in electrolytic cell 5 has decreased to the drought water volume (whether there is water in electrolytic cell 5 equal to or greater than the drought water volume).

[0129] In this way, by shaping the electrodes so that the change in capacitance of the electrodes becomes larger (steeper) for the same change in water volume, the first voltage difference can be changed steeply in response to changes in water volume, thereby improving the detection accuracy for the target water level (water volume).

[0130] (Modification) Next, a modification of the present disclosure will be described. The control unit 22 may perform control of the modification described below. A detailed flow of control executed by the control unit 22 in the modification will be described using the timing charts of FIGS. 8A and 8B.

[0131] 8A and 8B are diagrams showing an example of a time series of control procedures performed by the control unit 22 in a modification of the present disclosure.

[0132] First, the first acquisition process in the modified example will be described with reference to the timing chart of FIG. 8A.

[0133] The flow of the first acquisition process in the modified example will be described.

[0134] The processing up to timing T3 is the same as that described in FIG. 6A of the embodiment, and therefore the description thereof will be omitted.

[0135] After acquiring the first voltage at timing T3, the first voltage acquisition unit 61 sets the first connection unit 41 to the third mode and the second connection unit 42 to the seventh mode at timing T4. This causes the first capacitor 44 to be charged and the first electrode 18 to be discharged. In other words, the first capacitor voltage becomes VDD and the first electrode voltage becomes zero. Note that the time from timing T3 to timing T4 can be set arbitrarily, but a shorter time is preferable.

[0136] At timing T5, the first voltage acquisition unit 61 sets the first connection unit 41 to the second mode and the second connection unit 42 to the sixth mode. The first voltage acquisition unit 61 may set the first connection unit 41 to the second mode via the fourth mode. The first voltage acquisition unit 61 may set the second connection unit 42 to the sixth mode via the eighth mode. That is, the application of voltage to the first capacitor 44 is stopped, discharging of the first electrode 18 is stopped, and the first electrode 18 and the first capacitor 44 are connected in parallel. Because the first electrode 18 and the first capacitor 44 are connected in parallel, the first electrode voltage and the first capacitor voltage tend to be the same voltage. The first electrode voltage and the first capacitor voltage at this time are referred to as a third voltage. This third voltage is determined by the amount of charge stored in the first capacitor 44 before timing T5, the capacitance of the first electrode 18, and the capacitance of the first capacitor 44.

[0137] The time from timing T4 to timing T5 can be set arbitrarily, but at least the time until the charging of the first capacitor 44 is completed is required. The charging of the first capacitor 44 is completed when the amount of charge in the first capacitor 44 does not increase any further even if a voltage is applied. The time until the charging of the first capacitor 44 is completed can be measured in advance by experiment or the like, and a time equal to or greater than the maximum time required to charge the first capacitor 44 can be set as the time from timing T4 to timing T5.

[0138] The first voltage acquisition unit 61 acquires the third voltage at timing T6. Note that the time from timing T5 to timing T6 can be set arbitrarily, but at least a time is required for the third voltage to reach a stable voltage value. The time required for the third voltage to reach a stable voltage value may be measured in advance through an experiment or the like, and the time from timing T5 to timing T6 may be set to a time equal to or greater than the maximum time required for the third voltage to reach a stable voltage value.

[0139] This concludes the description of the flow of the first acquisition process in the modified example.

[0140] Next, the second acquisition process in the modified example will be described with reference to the timing chart of FIG. 8B.

[0141] The flow of the second acquisition process in the modified example will be described.

[0142] The processing up to timing T13 is the same as that described in FIG. 6B of the embodiment, and therefore the description thereof will be omitted.

[0143] After acquiring the second voltage at timing T13, the second voltage acquisition unit 62 sets the fourth connection unit 52 to mode 15 and the third connection unit 51 to mode 11 at timing T14. This causes the second electrode 19 to be charged and the second capacitor 54 to be discharged. In other words, the second electrode voltage becomes VDD and the second capacitor voltage becomes zero. Note that the time from timing T13 to timing T14 can be set arbitrarily, but a shorter time is preferable.

[0144] At timing T15, the second voltage acquisition unit 62 sets the fourth connection unit 52 to the 14th mode and the third connection unit 51 to the 10th mode. The second voltage acquisition unit 62 may set the fourth connection unit 52 to the 14th mode via the 16th mode. The second voltage acquisition unit 62 may also set the third connection unit 51 to the 10th mode via the 12th mode. That is, the application of voltage to the second electrode 19 is stopped, discharging of the second capacitor 54 is stopped, and the second electrode 19 and the second capacitor 54 are connected. At this time, the second electrode 19 and the second capacitor 54 are connected in parallel. Because the second electrode 19 and the second capacitor 54 are connected in parallel, the second electrode voltage and the second capacitor voltage tend to the same voltage. The second electrode voltage and the second capacitor voltage at this time are referred to as the fourth voltage. This fourth voltage is determined by the amount of charge stored in the second electrode 19 before timing T15, the capacitance of the second electrode 19, and the capacitance of the second capacitor 54.

[0145] The time from timing T14 to timing T15 can be set arbitrarily, but at least the time until the charging of second electrode 19 is completed is required. The charging of second electrode 19 is completed when the amount of charge on second electrode 19 does not increase any further even if a voltage is applied. The time until the charging of second electrode 19 is completed can be measured in advance by experiment or the like, and the time from timing T14 to timing T15 can be set to a time equal to or greater than the maximum time required for charging second electrode 19.

[0146] The second voltage acquisition unit 62 acquires the fourth voltage at timing T16. Note that the time from timing T15 to timing T16 can be set arbitrarily, but at least a time is required until the fourth voltage reaches a stable voltage value. The time until the fourth voltage reaches a stable voltage value can be measured in advance through an experiment or the like, and a time equal to or greater than the maximum time until the fourth voltage reaches a stable voltage value can be set as the time from timing T15 to timing T16.

[0147] This concludes the description of the flow of the second acquisition process in the modified example.

[0148] After the first and second acquisition processes are completed, the voltage difference calculation unit 63 calculates a first voltage difference, which is the difference between the first voltage and the second voltage. Specifically, the voltage difference calculation unit 63 calculates the first voltage difference by subtracting the second voltage from the first voltage.

[0149] Furthermore, the voltage difference calculation unit 63 calculates a second voltage difference, which is the difference between the fourth voltage and the third voltage. Specifically, the voltage difference calculation unit 63 calculates the second voltage difference by subtracting the third voltage from the fourth voltage.

[0150] Next, the voltage difference calculation unit 63 calculates an average voltage difference, which is the average of the first voltage difference and the second voltage difference.

[0151] In the present disclosure, the first electrode 18 and the second electrode 19 are arranged to exhibit the same capacitance characteristics when the amount of water in the electrolytic cell 5 is the same; however, there is some variation in the characteristics due to dimensional errors during electrode fabrication, etc. Furthermore, the first capacitor 44 and the second capacitor 54 are capacitors (capacitors) with the same capacitance, but there is also some variation in the characteristics due to manufacturing errors, etc. In the modified example of the present disclosure, the average voltage difference is calculated to suppress deterioration in the accuracy of water volume determination due to variation in the characteristics between the first electrode 18 and the second electrode 19 and between the first capacitor 44 and the second capacitor 54.

[0152] When the average voltage difference is not used to determine the water volume as in the modified example, variations in the characteristics of the first electrode 18 and the second electrode 19 and variations in the characteristics of the first capacitor 44 and the second capacitor 54 may affect the value of the first voltage difference. This reduces the accuracy of determining the water volume, and the accuracy of determining whether the amount of water in the electrolytic cell 5 is at a drought level becomes relatively low. On the other hand, in the modified example, the average voltage difference is used to determine the water volume, which improves the accuracy of determining the water volume, and improves the accuracy of determining whether the amount of water in the electrolytic cell 5 is at a drought level.

[0153] Next, if the average voltage difference is equal to or less than the drought threshold, the water volume determination unit 64 determines that the water volume in the electrolytic cell 5 is in a drought state, where water is insufficient. As described above, the drought threshold is used to determine whether a water volume greater than the drought water volume, which is the amount of water in the drought state where water is insufficient in the electrolytic cell 5, is present in the electrolytic cell 5. The drought threshold is a value determined in advance through experiments or the like and can be set arbitrarily. For example, the average voltage difference when the drought water volume is present in the electrolytic cell 5 may be calculated in advance through experiments or the like, and the calculated value may be stored in the memory unit 65 as the drought threshold. This allows for more accurate determination of the water volume in the electrolytic cell 5 as being in a drought state, where water is insufficient in the electrolytic cell 5. Because the drought water volume can be determined more accurately, the supply of current to the electrode unit 14 during a drought state can be suppressed, thereby suppressing deterioration of the electrode unit 14.

[0154] When it is determined that the water volume in the electrolytic bath 5 is at a drought level, the water volume determination unit 64 notifies the user via the notification unit 8 that the water volume in the electrolytic bath 5 is at a drought level. This allows the user to understand that the water volume in the electrolytic bath 5 is at a drought level. This allows the user to understand that action is required, such as refilling the water storage tank 9 with water. Refilling the water storage tank 9 with water allows current to be applied to the electrode unit 14, enabling continuous production of hypochlorous acid.

[0155] Here, it is preferable that the first acquisition process and the second acquisition process are performed at the same timing. That is, it is preferable that at least timing T3 and timing T13 are the same timing, and timing T6 and timing T16 are the same timing. It is also preferable that timing T1 and timing T11 are the same timing. It is also preferable that timing T2 and timing T12 are the same timing. It is also preferable that timing T4 and timing T14 are the same timing. It is also preferable that timing T5 and timing T15 are the same timing.

[0156] The reason is the same as that described above. By performing the first acquisition process and the second acquisition process at the same time, as in the modified example of the present disclosure, the influence of changes in stray capacitance can be suppressed. In other words, the water volume can be determined with high accuracy.

[0157] Specifically, the water volume determining unit 64 calculates the difference between the first voltage and the second voltage (first voltage difference) and the difference between the fourth voltage and the third voltage (second voltage difference) that were acquired at the same time when the same stray capacitance existed. Because the first voltage and the second voltage were acquired at the same time, the calculation of the first voltage difference cancels out the voltage change corresponding to the same stray capacitance between the first voltage and the second voltage (first electrode 18 and second electrode 19). Furthermore, because the fourth voltage and the third voltage were acquired at the same time, the calculation of the second voltage difference cancels out the voltage change corresponding to the same stray capacitance between the fourth voltage and the third voltage (second electrode 19 and first electrode 18). In other words, the change in stray capacitance (noise) that changes over time is prevented from affecting the values ​​of the first voltage difference and the second voltage difference.

[0158] If the first acquisition process and the second acquisition process are performed at different times, changes in stray capacitance (noise) that change over time are likely to affect the values ​​of the first voltage difference and the second voltage difference, which will deteriorate the accuracy of determining the water volume and reduce the accuracy of determining whether the water volume in the electrolytic cell 5 is in a drought state.

[0159] On the other hand, in this modified example, the first acquisition process and the second acquisition process are performed at the same time, which improves the accuracy of determining the water volume, and improves the accuracy of determining whether the water volume in the electrolytic cell 5 is in a drought state.

[0160] The relationship between the amount of water in the electrolytic cell 5 and the average voltage difference over time is also the same as in Figures 7A and 7B, and by changing the first voltage difference in Figures 7A and 7B to the average voltage difference, a similar relationship diagram is obtained.

[0161] Here, a comparative example of the electrostatic sensor 17 will be described. This comparative example is a capacitance-type sensor used in touch panels of mobile devices and the like. The capacitance-type sensor used in touch panels is defined as the comparative sensor. The comparative sensor can detect touch by a single electrode and detects touch by a person or the like based on a change in capacitance. Specifically, the voltage value or capacitance value when no person or the like is touching the sensor is used as a reference value, and touch by a person or the like is detected when there is a change from the reference value equal to or greater than a threshold value. Because the change from the reference value due to touch by a person or the like is large, using the comparative sensor does not pose any particular problem in such touch detection. However, this poses a problem when detecting changes in water volume in a situation where the electrode and water are separated and the water does not directly contact the electrode, as in the present disclosure. In a situation where the electrode and water are separated, as in the present disclosure, the changes in voltage value and capacitance value associated with changes in water volume are much smaller than the changes associated with touch detection. In other words, the comparative sensor cannot accurately detect changes in water volume in the present disclosure. However, the electrostatic sensor 17 of the present disclosure can detect changes in the water volume, improving the accuracy of determining the water volume, thereby improving the accuracy of determining whether the water volume in the electrolytic cell 5 is in a drought state.

[0162] The present disclosure has been described above based on embodiments and modified examples, but the present disclosure is in no way limited to the above, and it can be easily inferred that various improvements and modifications are possible within the scope that does not deviate from the spirit of the present disclosure.

[0163] For example, multiple independent electrostatic sensors 17 may be provided in the electrostatic sensor space 31. This allows multiple water levels to be detected with high accuracy. The amount of water in the water storage tank 9 can also be detected with high accuracy.

[0164] Furthermore, the first electrode 18 and the second electrode 19 may be integrally formed with the circuit board of the control unit 22. That is, the first electrode 18 and the second electrode 19 may be formed on the circuit board. For example, the first electrode 18 and the second electrode 19 may be formed by a copper foil pattern on the circuit board.

[0165] (Summary of the Invention) The space purification device according to the present disclosure comprises a main body case having an inlet and an outlet, an air blower that guides air from the inlet to the outlet, an electrolytic cell that is detachable from the main body case and mixes an electrolysis accelerator and water, an electrode unit that produces hypochlorous acid water from the electrolysis accelerator and water mixed in the electrolytic cell, an electrostatic sensor whose capacitance changes based on the amount of water in the electrolytic cell, and a determination unit that determines the amount of water in the electrolytic cell based on the capacitance of the electrostatic sensor, wherein the electrostatic sensor has first and second electrodes whose widths increase vertically downward, and the first and second electrodes are disposed at the same height and are configured to exhibit the same capacitance characteristics when the amount of water in the electrolytic cell is the same.

[0166] This makes it possible to improve the accuracy of detecting the amount of water to be detected using capacitance.

[0167] The first electrode and the second electrode may have bilaterally symmetrical shapes.

[0168] This allows the first electrode and the second electrode to exhibit the same capacitance characteristics when the amount of water in the electrolytic cell is the same.

[0169] The first electrode and the second electrode may have the same shape.

[0170] This allows the first electrode and the second electrode to exhibit the same capacitance characteristics when the amount of water in the electrolytic cell is the same.

[0171] The electrolytic cell may further include a first capacitor and a second capacitor whose capacitance does not change depending on the amount of water in the electrolytic cell, and the determination unit may perform a first acquisition process in which a voltage is applied to the first electrode to charge the first electrode, the application is stopped, and a first voltage is the voltage across the first electrode and the first capacitor when the first electrode and the first capacitor are connected, and a second acquisition process in which a voltage is applied to the second capacitor to charge the second capacitor, the application is stopped, and a second voltage is the voltage across the second electrode and the second capacitor when the second electrode and the second capacitor are connected, and determine the amount of water in the electrolytic cell based on a voltage difference that is the difference between the first voltage and the second voltage.

[0172] This allows changes in the amount of water to be detected, improving the accuracy of determining the amount of water.

[0173] The determination unit may also perform the first acquisition process and the second acquisition process at the same time.

[0174] This makes it possible to suppress the influence of changes in stray capacitance, i.e., to suppress changes in the voltage difference value due to the influence of changes in stray capacitance, thereby improving the accuracy of determining the water volume.

[0175] Furthermore, if the voltage difference is equal to or less than the drought threshold, the determination unit may determine that the amount of water in the electrolytic cell is in a drought state where the electrolytic cell is short of water.

[0176] This allows you to know when there is a shortage of water in the electrolytic cell.

[0177] The main body case may also have a partition wall that separates an electrostatic sensor space in which the electrostatic sensor is provided from an electrolytic cell space in which the electrolytic cell is provided.

[0178] This makes it possible to suppress corrosion of the electrostatic sensor.

[0179] The partition wall may separate the electrostatic sensor space from the electrolytic cell space so that volatilized hypochlorous acid cannot travel between them.

[0180] This makes it possible to suppress corrosion of the components in the electrostatic sensor space, including the electrostatic sensor.

[0181] The electrostatic sensor may also be provided at a position facing the side surface of the electrolytic cell across the partition wall.

[0182] This allows the capacitance of the electrostatic sensor to be changed in accordance with changes in the amount of water in the electrolytic cell.

[0183] The device may further include a purification unit that purifies the air by bringing hypochlorous acid water produced in the electrolytic cell into contact with air drawn in through the intake port.

[0184] This allows the generated hypochlorous acid water to be used to purify the air and space.

[0185] The device may further include a notification unit that notifies water volume information based on the water volume determination by the determination unit.

[0186] This allows the user to grasp the water volume information.

[0187] The space purification device according to the present disclosure is useful as a space purification device that purifies space.

[0188] REFERENCE SIGNS LIST 1 main body case 2 intake port 3 panel 5 electrolytic cell 6 outlet 8 notification unit 9 water storage tank 10 lid 12 air blower 13 air duct 14 electrode unit 15 purification unit 16 partition wall 17 electrostatic sensor 18 first electrode 19 second electrode 22 control unit 31 electrostatic sensor space 32 electrolytic cell space 40 first voltage application unit 41 first connection unit 42 second connection unit 43 first ground 44 first capacitor 50 second voltage application unit 51 third connection unit 52 fourth connection unit 53 second ground 54 second capacitor 60 determination unit 61 first voltage acquisition unit 62 second voltage acquisition unit 63 voltage difference calculation unit 64 water volume determination unit 65 memory unit 100 front surface 101 rear surface 102 first side surface 103 Second side surface 104 Upper surface 105 Lower surface D Space purification device T1 to T16 Timing

Claims

1. A space purification device comprising: a main body case having an inlet and an outlet; an air blower that guides air from the inlet to the outlet; an electrolytic cell that is detachable from the main body case and mixes an electrolysis accelerator and water; an electrode unit that produces hypochlorous acid water from the electrolysis accelerator and water mixed in the electrolytic cell; an electrostatic sensor whose capacitance changes based on the amount of water in the electrolytic cell; and a determination unit that determines the amount of water in the electrolytic cell based on the capacitance of the electrostatic sensor, wherein the electrostatic sensor has first and second electrodes whose widths increase vertically downward, and the first and second electrodes are disposed at the same height and are configured to exhibit the same capacitance characteristics when the amount of water in the electrolytic cell is the same.

2. The spatial purification device according to claim 1, wherein the first electrode and the second electrode are shaped symmetrically.

3. The space purification device according to claim 1, wherein the first electrode and the second electrode have the same shape.

4. The space purification device according to any one of claims 1 to 3, further comprising a first capacitor and a second capacitor whose capacitance does not change depending on the amount of water in the electrolytic cell, wherein the determination unit performs a first acquisition process of applying a voltage to the first electrode to charge the first electrode, stopping the application, and acquiring a first voltage which is the voltage across the first electrode and the first capacitor when the first electrode and the first capacitor are connected, and a second acquisition process of applying a voltage to the second capacitor to charge the second capacitor, stopping the application, and acquiring a second voltage which is the voltage across the second electrode and the second capacitor when the second electrode and the second capacitor are connected, and determines the amount of water in the electrolytic cell based on a voltage difference which is the difference between the first voltage and the second voltage.

5. The space purification device according to claim 4, wherein the determination unit performs the first acquisition process and the second acquisition process at the same time.

6. The space purification device according to claim 4, wherein the determination unit determines that the amount of water in the electrolytic cell is in a drought state where the electrolytic cell is short of water if the voltage difference is equal to or less than a drought threshold value.

7. The space purification device according to claim 1, wherein the main body case has a partition wall that separates an electrostatic sensor space in which the electrostatic sensor is provided from an electrolytic cell space in which the electrolytic cell is provided.

8. The space purification device according to claim 7, wherein the partition separates the electrostatic sensor space from the electrolytic cell space so that volatilized hypochlorous acid cannot pass between them.

9. The space purification device according to claim 7 or 8, wherein the electrostatic sensor is provided at a position facing the side surface of the electrolytic cell across the partition wall.

10. The space purification device according to claim 1, further comprising a purification unit that purifies the air drawn in through the intake port by bringing the hypochlorous acid water produced in the electrolytic cell into contact with the air.

11. The space purification device according to claim 1, further comprising a notification unit that notifies water volume information based on the water volume determination by the determination unit.

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