Washing machine and stain detection method

Abstract

To provide a washing machine and a stain detection method capable of detecting stains on the inner surface of an outer tub. [Solution] A washing machine according to one embodiment comprises a housing having an inlet through which the material to be treated is put in, an outer tub arranged within the housing, an inner tub arranged within the outer tub, the inner tub containing the material to be treated put in from the inlet and having a plurality of through holes formed therein, an illumination unit that outputs illumination light to illuminate the inside of the inner tub, and an illuminance detection unit arranged outside the outer tub that detects the illuminance on the outer surface of the outer tub.

Description

[Technical Field]

[0001] The present invention relates to a washing machine and a method for detecting soiling. [Background technology]

[0002] The washing machine has an outer tub and an inner tub placed inside the outer tub. Items to be treated, such as laundry, are placed in the inner tub. The inner tub has a through-hole formed in it. This allows treatment water (such as water containing detergent) stored in the outer tub to flow into the inner tub, allowing the items to be treated placed in the inner tub to be washed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-92335 Summary of the Invention [Problem to be solved by the invention]

[0004] If you use a washing machine for a long period of time, mold and other dirt will form on the inside of the outer tub.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a washing machine capable of detecting dirt on the inner surface of the outer tub and a method for detecting dirt on the outer tub. [Means for solving the problem]

[0006] [1] A washing machine according to one aspect of the present invention includes a housing having an inlet through which an object to be treated is put, an outer tub arranged within the housing, an inner tub arranged within the outer tub, the inner tub accommodating the object to be treated put in through the inlet and having a plurality of through holes formed therein, an illumination unit that outputs illumination light to illuminate the inside of the inner tub, and an illuminance detection unit that is arranged outside the outer tub and detects the illuminance of the outer surface of the outer tub.

[0007] In the washing machine described in [1] above, the interior of the inner tub can be illuminated by the illumination light output from the illumination unit. The inner tub has a through-hole, and the illumination light passes through the through-hole to illuminate the outer tub. Therefore, when the outer tub is viewed from the outside, the illuminance is high at least in the area facing the through-hole. When dirt forms on the inner surface of the outer tub, the illuminance on the outer surface decreases depending on the degree of dirt. Therefore, the illuminance detection unit can detect the dirt on the inner surface of the outer tub by detecting the illuminance on the outer surface.

[0008] [2] The washing machine described in [1] above may further include a control unit that determines whether or not the outer tub is soiled based on the detection result of the illuminance detection unit.

[0009] [3] The washing machine described in [2] above may further include a notification unit that notifies the user that the outer tub is dirty when the control unit determines that the outer tub is dirty.

[0010] [4] In the washing machine described in [1] or [2] above, the inlet may be formed on the front wall of the housing, and the illuminance detection unit may be located closer to the rear wall of the housing. In this case, the surroundings of the illuminance detection unit are darker, so that the illuminance detection by the illuminance detection unit is less affected by the brightness of the surroundings of the illuminance detection unit. This allows for more accurate detection of dirt.

[0011] [5] In the washing machine described in any one of [1] to [4] above, the illumination unit may be disposed near an upper portion of the housing so as to output the illumination light downward, and the illuminance detection unit may be disposed near a lower portion of the housing. In this case, the illumination light passing through a through-hole formed in the inner tub within the inspection range of the illuminance detection unit includes illumination light propagating forward from the illumination unit. Therefore, the amount of illumination light passing through the through-hole increases. As a result, the difference in illuminance between when there is dirt and when there is no dirt increases, making it easier to detect dirt.

[0012] [6] In the washing machine according to any one of [1] to [4] above, the outer tub may be made of a material that is transmissive to the illumination light.

[0013] [7] A dirt detection method according to another aspect of the present invention is a detection method for detecting dirt on the inner surface of an outer tub arranged in a housing of a washing machine, and includes a detection step of detecting the illuminance on the outer surface of the outer tub while illuminating with illumination light an inner tub arranged in the outer tub, the inner tub containing the object to be treated and having a plurality of through holes, and a determination step of determining whether or not there is dirt on the inner surface of the outer tub based on the detection result of the detection step.

[0014] In the dirt detection method described in [7] above, in the detection step, the illuminance on the outer surface of the outer tub is detected while illuminating the inner tub with illumination light. Furthermore, in the determination step, the presence or absence of dirt on the inner surface of the outer tub is determined based on the detection result of the detection step. As a result, the detection method can detect dirt on the inner surface of the outer tub.

[0015] [8] In the contamination detection method described in [7] above, the detection step may be performed when the object to be treated is not placed in the inner tank. When the object to be treated is not placed in the inner tank, the amount of light output from the through-hole toward the outer tank increases. As a result, the difference in illuminance between when contamination is present and when it is not present increases, making it easier to detect contamination.

[0016] [9] In the dirt detection method described in [7] or [8] above, the judgment step may determine whether or not the dirt is present by comparing the detection result of the detection step with a reference illuminance corresponding to a threshold value that distinguishes between cases where dirt is present on the inner surface of the outer tank and cases where it is not present.

[0017]

[10] The dirt detection method described in any of [7] to [9] above may include a notification step of notifying a user that dirt has been detected on the inner surface of the outer tub if the determination step detects dirt on the inner surface of the outer tub. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a washing machine and a dirt detection method that can detect dirt on the inner surface of the outer tub. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a cross-sectional view illustrating a schematic configuration of a washing machine according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing the electrical configuration of the washing machine shown in FIG. [Figure 3] FIG. 3 is a flowchart of an example of a stain detection method. [Figure 4] FIG. 4 is a diagram showing the outer surface of the outer tank when the outer tank is not contaminated in a verification experiment. [Figure 5] FIG. 5 is a diagram showing the outer surface of the outer tub in FIG. 4 when tissue paper, which is a model of soiling, is inserted between the outer tub and the inner tub. [Figure 6] FIG. 6 is a diagram for explaining another example of the arrangement position of the illuminance detection unit. [Figure 7] FIG. 7 is a diagram for explaining still another example of the arrangement position of the illuminance detection unit. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The same elements are designated by the same reference numerals, and duplicated explanations will be omitted. The dimensional proportions in the drawings do not necessarily correspond to the actual proportions.

[0021] The overall configuration of a washing machine 1 according to one embodiment will be described with reference to FIG. 1. FIG. 1 is a schematic diagram illustrating the general configuration of a washing machine. In the following description, the X and Z directions shown in FIG. 1 may be used to describe the washing machine 1. The Z direction corresponds to the height direction (or up-down direction or vertical direction) of the washing machine 1 in the installed state shown in FIG. 1. The X direction corresponds to the front-to-back direction of the washing machine 1 in FIG. 1. In the following description, unless otherwise specified, the X and Z directions are orthogonal to each other. The direction perpendicular to the plane of FIG. 1 corresponds to the left-to-right direction of the washing machine 1. In this specification, terms indicating directions such as "front," "back," "up," "down," "left," and "right" are terms based on the installed state of the washing machine 1.

[0022] The washing machine 1 is a drum-type washing machine. The washing machine 1 has a function of washing objects to be treated, such as clothes. The washing machine 1 has a housing 10 having, for example, a rectangular parallelepiped shape. The shape of the housing 10 can be changed as appropriate. A circular door 11 that can be opened and closed is attached to a front wall 101 of the housing 10. The door 11 has a window 11a. The window 11a protrudes into the housing 10. The window 11a may be door glass. The front wall 101 of the housing 10 has a circular inlet 101a formed therein, through which objects to be treated in the washing machine 1 are put. The inlet 101a is opened and closed by the door 11.

[0023] An outer tub 12 and a drum (inner tub) 13 are arranged within the housing 10. Both the outer tub 12 and the drum 13 have a cylindrical shape with a bottom. The outer tub 12 is also known as an outer tub body. The outer tub 12 is made of a material that does not block light. An example of the material for the outer tub 12 is resin. The outer tub 12 is formed, for example, from white resin. In this embodiment, the drum 13 also functions as a dehydration tub. An example of the material for the drum 13 is stainless steel. The drum 13 is rotatably arranged within the outer tub 12. The outer tub 12 and the drum 13 are arranged concentrically (coaxially) with respect to a central axis extending, for example, in the X direction. The central axes of the outer tub 12 and the drum 13 may extend in a direction inclined relative to the X direction.

[0024] The outer tank 12 is a tank capable of storing treated water. In this specification, "treated water" refers to a liquid appropriate for each process, such as the washing process and rinsing process, of the object to be treated. Therefore, in the washing process, the treated water may be water (liquid) containing detergent, etc., and in the rinsing process, the treated water may be tap water. In the rinsing process, the treated water may contain a fabric softener.

[0025] The outer tub 12 is elastically supported by a support mechanism (not shown) within the housing 10. The support mechanism may include, for example, at least one damper and at least one spring. The outer tub 12 has a circular opening 12a located in front of the opening 13a of the drum 13.

[0026] The peripheral edge of opening 12a and the peripheral edge of input port 101a are connected by an annular packing 14 made of an elastic material. The cross-sectional shape of packing 14 may be set appropriately. The peripheral surface of closed door 11 contacts packing 14, and the gap between input port 101a and door 11 is watertight.

[0027] The material to be treated is accommodated inside the drum 13. A large number of through holes 13b are formed on the inner peripheral surface of the drum 13. The through holes 13b allow treated water to flow from the outer tank 12 into the inner tank 13, and also allow treated water to flow from the inner tank 13 to the outer tank 12. The through holes 13b also function as dewatering holes. A plurality of (e.g., three) baffles 13c are provided on the inner peripheral surface of the drum 13 at equal intervals in the circumferential direction. A balancer (not shown) may be provided on the inner peripheral surface of the front part of the drum 13.

[0028] A drive motor 15 for rotating the drum 13 is installed within the housing 10 behind the outer tub 12. The drive motor 15 may be disposed between the rear wall 102 of the housing 10 and the outer tub 12. The rotation shaft 15a of the drive motor 15 extends, for example, along the central axis of the drum 13 and is connected to a portion of the drum 13. The rotation shaft 15a and the drum 13 may be connected via a pulley, a speed reduction mechanism, or the like, or may be connected directly. During the washing and rinsing processes, the drive motor 15 rotates the drum 13 at a relatively low rotation speed so that the centrifugal force acting on the objects to be treated in the drum 13 is less than gravity, causing the objects to tumble. During the spin-drying process, the drive motor 15 rotates the drum 13 at a relatively high rotation speed so that the centrifugal force acting on the objects to be treated in the drum 13 is greater than gravity, causing the objects to stick to the inner circumferential surface of the drum 13.

[0029] Washing machine 1 has water supply mechanism 20 above outer tub 12 within housing 10. Water supply mechanism 20 is a mechanism for supplying treated water to outer tub 12. An example of water supply mechanism 20 will be described based on the configuration shown in FIG.

[0030] The water supply mechanism 20 may be configured to include a water supply pipe 21, a water supply valve 22, an automatic treatment agent dispenser 23, and a water supply pipe 24. The water supply pipe 21 and the water supply pipe 24 may be flexible hoses, or may be made of piping materials other than hoses. When the water supply valve 22 is opened, tap water from a water faucet is supplied into the automatic treatment agent dispenser 23 through the water supply pipe 21.

[0031] The automatic treatment agent dispenser 23 dispenses a detergent (treatment agent) into tap water supplied from the water supply pipe 21 to produce treated water. The treated water is supplied to the outer tub 12 through the water supply pipe 24. Such treated water containing detergent is used in the washing process. The automatic treatment agent dispenser 23 may be configured to be able to produce treated water containing a fabric softener, for example, in addition to the treated water containing the detergent. The treated water containing fabric softener is used, for example, in the rinsing process.

[0032] Switching between a mode for adding detergent to tap water and a mode for adding fabric softener to tap water within the automatic treatment agent dispenser 23 may be performed by controlling the flow path within the automatic treatment agent dispenser 23 (for example, by switching using a valve). The automatic treatment agent dispenser 23 may also be configured to allow selection of a mode in which a treatment agent such as detergent is not dispensed into tap water. In this case, tap water is supplied to the outer tub 12. The water supply mechanism 20 may have a water supply pipe that supplies tap water to the outer tub 12 without passing through the automatic treatment agent dispenser 23.

[0033] A drainage mechanism 30 is provided below outer tub 12 within housing 10. Drainage mechanism 30 is a mechanism for discharging treated water within outer tub 12 to the outside of washing machine 1.

[0034] An example of the drainage mechanism 30 will be described based on the embodiment shown in Fig. 1. The drainage mechanism 30 may be configured to include a drainage pipe 31, a drainage filter unit 32, a drainage pipe 33, and a drainage valve 34. The drainage pipes 31 and 33 may be flexible hoses, or may be made of piping materials other than hoses.

[0035] Drain pipe 33 connects the lower part of outer tub 12 to drain filter unit 32. Drain filter unit 32 removes foreign matter mixed in the treated water flowing in from drain pipe 31. Examples of foreign matter removed by drain filter unit 32 include lint and hair. Drain pipe 33 is connected to drain filter unit 32. Drain pipe 33 carries the treated water from which foreign matter has been removed by drain filter unit 32. The end of drain pipe 33 opposite to the end connected to drain filter unit 32 is connected to a drain outlet provided in a waterproof pan or the like outside washing machine 1. Drain valve 34 is provided on drain pipe 33. Opening and closing drain valve 34 controls the discharge of treated water from outer tub 12. When drain valve 34 is opened, treated water discharged from outer tub 12 through drain pipe 31 flows through drain filter unit 32 and into drain pipe 33. As a result, the treated water is discharged to the drain outlet outside washing machine 1.

[0036] The drain filter unit 32 may have a filter body 321 that removes the above-mentioned foreign matter, and a case 322 that detachably houses the filter body 321. In the example shown in Fig. 1, the drain pipe 31 and the drain pipe 33 are connected to the case 322. In the example shown in Fig. 1, the drain filter unit 32 is configured so that the filter body 321 can be detachably attached to the case 322 from the front wall 101 of the housing 10.

[0037] As described above, treated water is supplied into outer tub 12, and therefore, when washing machine 1 is used for a long period of time, dirt may form on inner surface 121 of outer tub 12. The dirt includes mold, fiber debris, detergent residue, etc. Washing machine 1 further includes lighting unit 41 and illuminance detection unit 42 to detect the dirt.

[0038] Illumination unit 41 outputs illumination light L to illuminate the inside of drum 13. Illumination unit 41 may be located at an upper portion within housing 10. For example, illumination unit 41 may be located near the top of input port 101a so as to be able to illuminate the inside of drum 13, as shown in FIG. 1. In the embodiment shown in FIG. 1, illumination unit 41 is attached to the top of annular gasket 14 so as to be able to output illumination light L into drum 13. In drum-type washing machine 1, treated water tends to accumulate at the bottom of drum 13, so if illumination unit 41 is located near the top of housing 10, illumination unit 41 is less likely to be affected by the treated water. An example of illumination unit 41 is an LED.

[0039] The illuminance detection unit 42 detects the illuminance of the outer surface 122 of the outer tub 12. The illuminance detection unit 42 is disposed outside the outer tub 12. In FIG. 1, the illuminance detection unit 42 is disposed between the top wall 103 of the housing 10 and the peripheral wall of the outer tub 12. The installation position of the illuminance detection unit 42 is not limited as long as it can detect the illuminance of the outer surface 122. As shown in FIG. 1, the illuminance detection unit 42 may be attached to the underside of the automatic processing agent dosing device 23. The illuminance detection unit 42 may be disposed on the top wall 103, the water supply pipe 21, or another support member. The illuminance detection unit 42 detects the illuminance of an area 122a of the outer surface 122 of the outer tub 12, which is within the detection range a of the illuminance detection unit 42. The illuminance detection unit 42 may be an illuminance sensor (or an illuminance meter).

[0040] The washing machine 1 will be further described with reference to FIG. 2. FIG. 2 is a block diagram showing an example of the electrical configuration of the washing machine 1. As shown in FIG. 2, the washing machine 1 has a control unit 51 that controls the washing machine 1. The washing machine 1 may further include an operation unit 52, a memory unit 53, and a display unit (notification unit) 54. Below, a configuration in which the washing machine 1 has the operation unit 52, the memory unit 53, and the display unit 54 will be described.

[0041] Operation unit 52 includes a power button for turning on and off the power to the device, a start button for starting operation, and a program selection button for selecting any one of a plurality of operation programs available for washing machine 1. Operation unit 52 outputs an input signal corresponding to the button operated by the user to control unit 51. Operation unit 52 may be located in any position in housing 10 that is easy for the user of washing machine 1 to operate. For example, operation unit 52 may be located on the upper part of front wall 101 of housing 10, or on top wall 103 (see FIG. 1) of housing 10.

[0042] The storage unit 53 includes a memory element (for example, an EEPROM, a RAM, etc.). The storage unit 53 stores programs for executing various operation courses available in the washing machine 1, such as a wash course, and a program for detecting dirt on the outer tub 12. The storage unit 53 stores various parameters and control flags used to execute these programs, as well as information necessary to perform various functions of the washing machine 1.

[0043] Display unit 54 includes a light-emitting element such as an LED, and a display such as a liquid crystal panel. Display unit 54 displays the selected operation course and the progress of each operation course in response to a control signal from control unit 51. Display unit 54 also functions as a notification unit that notifies the user of an abnormality in washing machine 1. An "abnormality" in washing machine 1 also includes a case where the dirt in outer tub 12 exceeds an allowable range. Display unit 54 may be located in the same location as operation unit 52 in housing 10.

[0044] The control unit 51 includes a CPU, etc. The control unit 51 is electrically connected to the operation unit 52, the memory unit 53, the display unit 54, the drive motor 15, the water supply valve 22, the automatic processing agent dispenser 23, the drain valve 34, the lighting unit 41, and the illuminance detection unit 42.

[0045] In washing machine 1, when a user selects a washing course on operation unit 52, control unit 51 performs washing (washing process, rinsing process, spin-drying process, etc.) of the items to be treated placed in washing machine 1 by controlling, for example, drive motor 15, water supply valve 22, automatic treatment agent dispenser 23, and drain valve 34 in accordance with a program stored in memory unit 53. Control by control unit 51 of automatic treatment agent dispenser 23 includes, for example, selection of the treatment agent to be dispensed, control of the timing of dispensing, etc.

[0046] In washing machine 1, control unit 51 controls lighting unit 41 and illuminance detection unit 42, thereby making it possible to detect dirt on outer tub 12. A method for detecting dirt on outer tub 12 in washing machine 1 will be described below. Fig. 3 is a flowchart showing the basic flow of the dirt detection method.

[0047] When the user turns on the power of the washing machine 1 by operating the operation unit 52, the control unit 51 controls the illumination unit 41 to emit illumination light L from the illumination unit 41 (illumination step S1). The illumination unit 41 may automatically output illumination light L when the power of the washing machine 1 is turned on. In this case, it is not necessary for the control unit 51 to control the illumination unit 41, and therefore the control unit 51 and the illumination unit 41 do not need to be electrically connected.

[0048] When illumination light L is being output from illumination unit 41 as described above, illuminance detection unit 42 detects the illuminance of outer surface 122 of outer tub 12 (illuminance detection step S2). When illumination light L is output from illumination unit 41, control unit 51 may operate illuminance detection unit 42, or illuminance detection unit 42 may operate automatically when washing machine 1 is turned on. In the flowchart shown in FIG. 3, illumination step S1 and illuminance detection step S2 are illustrated separately, but illumination step S1 may be part of illuminance detection step S2.

[0049] The illuminance detection unit 42 inputs the detection result to the control unit 51. The control unit 51 determines whether the inner surface 121 of the outer tub 12 is soiled or not based on the detection result of the illuminance detection unit 42 (determination step S3). Specifically, the control unit 51 compares the illuminance detected by the illuminance detection unit 42 with a reference illuminance. If the illuminance is equal to or less than the reference illuminance, the control unit 51 determines that the inner surface 121 of the outer tub 12 is soiled. If the illuminance detected by the illuminance detection unit 42 is greater than the reference illuminance, the control unit 51 determines that the inner surface 121 is not soiled. The reference illuminance may be, for example, an illuminance corresponding to a threshold value that distinguishes between cases where soiling occurs and cases where soiling does not occur, based on the results of a test conducted in advance before the washing machine 1 is shipped from a factory. The reference illuminance may be, for example, an illuminance that is determined by taking into account a preset allowable illuminance decrease from the illuminance detected when the washing machine 1 is first turned on after purchase. The reference illuminance may be stored in the storage unit 53.

[0050] If the control unit 51 determines in the determination step S3 that the inner surface 121 of the outer tub 12 is dirty ("YES" in the determination step S3), the control unit 51 may control the display unit 54 to notify the user of this (notification step S4). The notification may be, for example, a message indicating that the outer tub 12 is dirty displayed on the display unit 54, or a part that should be lit when the outer tub 12 is dirty may be lit. As described above, if the notification step S4 is performed, the processing flow associated with the dirt detection is terminated after the notification step S4 is performed.

[0051] In the determination step S3, when the control unit 51 determines that the outer tub 12 is not dirty ("NO" in the determination step S3), the flow of processing associated with the detection of dirt is terminated.

[0052] The washing machine 1 includes an illumination unit 41 and an illuminance detection unit 42. When illumination light L is output from the illumination unit 41, the interior of the inner tub 13 is illuminated by the illumination light L. Because a through-hole 13b is formed in the inner tub 13, the illumination light L illuminating the interior of the inner tub 13 is output through the through-hole 13b into the outer tub 12, and the inner surface 121 of the outer tub 12 is also illuminated by the illumination light L. Therefore, when the outer tub 12 is viewed from the outside, at least the portion facing the through-hole 13b appears bright. In other words, the illuminance of at least the portion of the outer tub 12 facing the through-hole 13b is high. If dirt adheres to the inner surface 121 of the outer tub 12, the illuminance of the portion facing the through-hole 13b when viewed from the outside decreases depending on the degree of dirt. Therefore, by detecting the illuminance of the outer surface 122, it is possible to detect dirt on the inner surface 121 of the outer tub 12.

[0053] The results of an experiment verifying that the illuminance on the outer surface 122 decreases when the inner surface 121 of the outer tub 12 becomes dirty will be explained using Figures 4 and 5. In the experiment, tissue paper P was used as a model of dirt on the outer tub 12, and the change in illuminance on the outer surface 122 was observed when tissue paper P was inserted between the outer tub 12 and the inner tub 13 and when it was not inserted.

[0054] Figure 4 is a diagram showing the outer surface 122 of the outer tub 12 when the outer tub 12 is not soiled in a verification experiment. That is, Figure 4 is a diagram showing the state of the outer surface 122 when no tissue paper P is sandwiched between the outer tub 12 and the inner tub 13. As shown in area A in Figure 4, the portion of the outer surface 122 of the outer tub 12 facing the through-hole 13b was bright.

[0055] Fig. 5 is a diagram showing the outer surface 122 of outer tub 12 when tissue paper P, a model of dirt, is inserted between outer tub 12 and inner tub 13 in Fig. 4. As shown in Fig. 5, it can be seen that in region A, the brightness of the portion facing through hole 13b is reduced compared to the case of Fig. 4, i.e., the illuminance is reduced. Therefore, it was verified that dirt on inner surface 121 of outer tub 12 that occurs over a long period of use of washing machine 1 can be detected based on the illuminance of outer surface 122 of outer tub 12.

[0056] To detect contamination of the outer tub 12, the illuminance of the portion facing the through-hole 13b when viewed from the outside of the outer tub 12 is utilized. Therefore, the outer tub 12 may be made of a material that can transmit at least the illumination light L.

[0057] Before performing the illumination step S1 to detect dirt on outer tub 12, i.e., before outputting illumination light L from illumination unit 41, the illuminance of outer surface 122 may be detected by illuminance detection unit 42. In this case, control unit 51 uses the difference between the illuminance detected before performing illumination step S1 and the illuminance detected while performing illumination step S1 as the illuminance for dirt detection. This allows dirt to be detected without the influence of the brightness inside washing machine 1 when detecting dirt on outer tub 12 (brightness when illumination light L is not being output), thereby enabling more accurate dirt detection.

[0058] When detecting contamination in the outer tub 12, contamination detection may be performed when no treatment object has been placed in the inner tub 13. In this case, a step of checking whether or not no treatment object has been placed in the inner tub 13 (whether or not the inner tub 13 is empty) may be performed before performing the illumination step S1. For example, before performing the illumination step S1, the control unit 51 drives the drive motor 15 to rotate the inner tub 13. The rotational torque at that time may be detected, and based on the detected rotational torque, it may be determined whether or not a treatment object has been placed in the inner tub 13.

[0059] When detecting contamination in the outer tank 12 when no material to be treated has been placed in the inner tank 13, the illumination light L is likely to be reflected within the inner tank 13, and a large amount of light is output from the through-holes 13b toward the outer tank 12. As a result, the difference in illuminance between when contamination exists and when it does not exists becomes large, making it easier to detect contamination.

[0060] Although the embodiments of the present invention have been described above, the present invention is not limited to the illustrated embodiments, but is intended to include the scope indicated by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0061] As shown in FIG. 6, illuminance detection unit 42 may be disposed at the rear of housing 10 (in other words, closer to rear wall 102). In washing machine 1, external light does not enter washing machine 1 from any source other than input port 101a, so the inside of washing machine 1 is usually dark. In particular, since the rear of housing 10 is dark, illuminance detection by illuminance detection unit 42 is less susceptible to the influence of the brightness of the environment around illuminance detection unit 42. This allows for more accurate detection of dirt.

[0062] The illuminance detection unit 42 may be disposed near the bottom of the housing 10, as shown in Fig. 7. Specifically, the illuminance detection unit 42 may be disposed below the outer tub 12. In the embodiment shown in Fig. 7, the illuminance detection unit 42 is attached to the drain pipe 33, but the installation position of the illuminance detection unit 42 is not limited to the embodiment shown in Fig. 7. For example, the illuminance detection unit 42 may be attached to the bottom wall of the housing 10 or to another support member.

[0063] 7, the illumination unit 41 is also disposed near the upper part of the housing 10, and the illumination unit 41 outputs illumination light L downward. Therefore, in a configuration in which the illuminance detection unit 42 is disposed near the lower part of the housing 10, the illumination light L that passes through the through-hole 13b within the inspection range of the illuminance detection unit 42 includes illumination light L that has propagated forward from the illumination unit 41. Therefore, the amount of illumination light L that passes through the through-hole 13b is greater than in a case in which only the illumination light L reflected within the inner tank 13 passes through the through-hole 13b. As a result, the difference in illuminance between when contamination is present and when it is not present is greater, making it easier to detect contamination.

[0064] The notification unit indicating that dirt has been detected may be configured to notify the user that dirt has been detected by, for example, sound.

[0065] The detection of the dirt on the outer tub 12 may be carried out after the operation course, such as the washing course selected by the user, has been completed.

[0066] The washing machine 1 may have other functions in addition to washing the object to be treated, such as a function to dry the object to be treated.

[0067] The washing machine according to the present invention is not limited to a drum type washing machine, but may be, for example, a vertical washing machine.

[0068] The above-described embodiments and modifications may be combined as appropriate without departing from the spirit of the present invention. [Explanation of symbols]

[0069] 1...Washing machine, 10...Housing, 12...Outer tank, 13...Drum (inner tank), 13b...Through hole, 41...Illumination section, 42...Illuminance detection section, 51...Control section, 54...Display section (notification section), 101...Front wall, 101a...Inlet, 102...Rear wall, 121...Inner surface, 122...Outer surface, L...Illumination light.

Claims

1. a housing having an inlet through which the material to be treated is introduced; an outer tank disposed within the housing; An inner tank disposed in the outer tank, the inner tank accommodating the object to be treated introduced through the introduction port, and having a plurality of through holes formed therein; an illumination unit that outputs illumination light that illuminates the inside of the inner tank; an illuminance detection unit disposed outside the outer tub and detecting illuminance on the outer surface of the outer tub; Equipped with washing machine.

2. The control unit further includes a controller that determines whether or not the outer tub is dirty based on the detection result of the illuminance detector. The washing machine according to claim 1.

3. The washing machine further includes a notification unit that notifies a user that the outer tub is dirty when the control unit determines that the outer tub is dirty. The washing machine according to claim 2.

4. The insertion port is formed in the front wall of the housing, The illuminance detection unit is disposed near the rear wall of the housing. The washing machine according to claim 1 or 2.

5. the illumination unit is disposed near an upper portion of the housing so as to output the illumination light downward; The illuminance detection unit is disposed near the bottom of the housing. The washing machine according to claim 1 or 2.

6. The outer tank is made of a material that is transmissive to the illumination light. The washing machine according to claim 1 or 2.

7. A detection method for detecting dirt on the inner surface of an outer tub disposed in a housing of a washing machine, comprising: a detection step of detecting the illuminance of an outer surface of the outer tank while illuminating the inside of the inner tank with illumination light, the inner tank being disposed within the outer tank and containing the object to be treated and having a plurality of through holes; a determination step of determining whether or not the inner surface of the outer tub is contaminated based on the detection result of the detection step; Equipped with Dirt detection methods.

8. The detection step is carried out in a state where the object to be treated has not been placed in the inner tank. The method for detecting dirt according to claim 7 .

9. In the determination step, the presence or absence of contamination is determined by comparing a reference illuminance corresponding to a threshold value that distinguishes between a case where contamination has occurred on the inner surface of the outer tub and a detection result in the detection step. The stain detection method according to claim 7 or 8.

10. and a notification step of notifying a user that dirt has been detected on the inner surface of the outer tub when the determination step detects dirt. The stain detection method according to claim 7 or 8.

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