JP2008086634A - Washing apparatus using molecule detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a washing apparatus capable of achieving high washing effect and rinsing effect by accurately detecting concentration of detergent molecules contained in a solution. <P>SOLUTION: The washing apparatus includes a detergent sensor 52 for detecting concentration of the detergent in a washing liquid in a water receiving tub, and a control circuit for controlling a water pouring valve, a detergent pouring device, a drain valve and a washing/spin-drying tub from a detected result by the detergent sensor 52. The detergent sensor 52 has a prism 84 having a first reflection surface, a metallic layer 86 formed on the first reflection plane of the prism 84, a light source 80 arranged opposite to the metallic layer 86 so that light enters the first reflection surface in a total internal reflection condition, a hydrophobic layer 90 formed on the metallic layer 86, and a photo-detector 92 for detecting a change in positions of a generated dark line, by surface plasmon resonance, in reflection light which is emitted from the light source 80 and reflected by the reflection plane. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus for cleaning a substance, and more particularly, to a cleaning apparatus including an apparatus for detecting molecules having amphiphilic properties such as detergents using surface plasmon resonance.

  In recent years, automatic washing apparatuses such as washing machines and dishwashers have been developed. In such an automatic cleaning apparatus, it is important to measure the detergent concentration in the solution. This is because if the concentration of the detergent contained in the rinsing water at the end of rinsing is high, the rinsing effect becomes insufficient, and if the concentration of the detergent is too low during washing, the washing ability is lowered. Therefore, it is necessary to measure the detergent concentration in the solution and maintain an appropriate detergent concentration.

As a method of measuring the detergent concentration, there is a method of measuring the detergent concentration by measuring the electrical conductivity of a solution in which the detergent is dissolved as disclosed in Patent Document 1. According to this method, at the time of cleaning, detergent and water are continuously added until it is suitable for cleaning based on the measurement result of electric conductivity. Further, at the time of rinsing, water is continuously added until the concentration of the detergent is sufficiently reduced based on the measurement result of electric conductivity.
JP-A-6-218183

  By the way, the cleaning ability of the detergent is determined by the concentration of the surfactant dissolved in the solution. The detergent molecules are separated into an ionic surfactant having a detergency in water and a counter ion having no detergency. Counter ions that do not have a cleaning function greatly contribute to the electric conductivity of the detergent solution.

On the other hand, an ionic surfactant having a detergency has a higher molecular weight than a counter ion, and therefore contributes little to electric conductivity. For example, sodium dodecyl sulfate (C ₁₈ H ₃₇ SO ₃ Na), which is a typical surfactant, has a molecular weight of 333.59, which is the molecular weight of C ₁₈ H ₃₇ SO ₃ ^— , which is a surfactant site. The molecular weight of the ion Na ⁺ is 22.99.

  Therefore, according to the measurement of electrical conductivity, the amount of counter ions in the aqueous solution can be measured, but the amount of surfactant cannot be measured. As a result, even if the electrical conductivity is measured, the surfactant concentration cannot be accurately detected, and the cleaning ability cannot be accurately known. Therefore, there is a possibility that the cleaning is not performed sufficiently or the rinsing is not performed sufficiently.

  In addition to ionic surfactants, there are nonionic surfactants, but nonionic surfactants do not ionize in water, so there is no change in electrical conductivity due to changes in dissolved concentration. The method described in Document 1 cannot be applied.

  Therefore, it is an object of the present invention to more accurately detect the concentration of detergent molecules contained in a solution compared to measuring electrical conductivity, thereby achieving a high cleaning effect and a rinsing effect. It is to provide a device.

  The cleaning apparatus according to the first aspect of the present invention includes a cleaning tank, a water supply means for supplying water to the cleaning tank, a detergent supply means for supplying detergent to the cleaning tank, and a cleaning tank. Cleaning means for cleaning the cleaned object using the cleaning liquid obtained by mixing the water supplied by the water supply means and the detergent supplied by the detergent supply means, and the detergent in the cleaning liquid in the cleaning tank A molecular detection device for detecting the concentration of water, a discharge means for discharging the cleaning liquid in the cleaning tank, and a water supply means, a detergent supply means, a discharge means, and a cleaning based on the detection result from the molecular detection device Control means for controlling the means. The molecular detection device is a molecular detection device that detects amphiphilic molecules using surface plasmon resonance, and includes a transparent substrate having a first reflective surface, and a metal formed on the first reflective surface of the transparent substrate. A light source disposed on the opposite side of the metal layer with respect to the first reflective surface so that light is incident on the first reflective surface under total reflection conditions; a hydrophobic layer formed on the metal layer; Detecting means for detecting a change in the position of the dark line caused by surface plasmon resonance in the reflected light emitted by the light source and reflected by the reflecting surface. The molecular detection device is arranged so that the hydrophobic layer faces a portion of the cleaning tank where the cleaning water is stored.

  According to this cleaning apparatus, based on the detection result of the detergent concentration by the molecular detector, the control means includes the water injection means, the detergent injection means, and the cleaning means for executing the cleaning of the object to be cleaned disposed in the cleaning tank. Be controlled. Therefore, it is possible to automatically control the introduction and rinsing of the detergent without waste so as to reach an appropriate detergent concentration based on the detection result. As a result, detergent and water can be saved, and the environmental load can be reduced. Further, according to the molecular detection device included in the cleaning device, the light emitted from the light source is totally reflected by the metal layer formed on the first reflecting surface of the transparent substrate. In the reflected light totally reflected by the metal layer, a dark line is generated by surface plasmon resonance. A hydrophobic layer is formed on the metal layer, and the optical properties such as the refractive index of the interface between the metal layer and the hydrophobic layer depend on the amount of the hydrophobic group of the amphiphilic molecule adsorbed on the hydrophobic layer. Changes, and the position of the dark line changes. This change in position is detected by detection means. The change in the position of the dark line changes depending on the amount of amphiphilic molecules adsorbed on the hydrophobic layer. The amount of amphiphilic molecules adsorbed on the hydrophobic layer varies depending on the concentration of amphiphilic molecules present in the space where the hydrophobic layer faces. Therefore, the concentration of the amphiphilic molecule can be detected by using the change in the position of the dark line caused by the surface plasmon resonance. Amphiphilic molecules are reversibly adsorbed to or separated from the hydrophobic layer depending on the concentration of the molecule in water. Therefore, the detection device does not need to be disposable and can be used repeatedly. Furthermore, a drug that removes amphiphilic molecules is not necessary. As a result, it is possible to provide a cleaning apparatus that can detect the concentration of detergent molecules contained in a solution more accurately than that for measuring electrical conductivity, thereby realizing a high cleaning effect and a rinsing effect. it can.

  Preferably, the control means is responsive to determining that the concentration of the detergent is less than a predetermined first threshold value based on a signal from the molecular detection device when performing the washing by the washing means. The detergent supply means is controlled to add to the washing tank.

  According to this cleaning apparatus, when the cleaning by the cleaning means is executed, the control means controls the detergent supply means to add the detergent to the cleaning tank based on the signal from the molecular detection device. Therefore, when the concentration of the detergent is low and not suitable for washing, the detergent concentration can be increased to a concentration suitable for washing. As a result, it is possible to provide a cleaning apparatus capable of performing appropriate cleaning with a sufficient detergent concentration.

  Preferably, the control means is responsive to the determination that the concentration of the detergent is equal to or higher than a predetermined second threshold value based on a signal from the molecular detection device during the rinsing by the cleaning means. The water supply means is controlled to add to the washing tank.

  According to this cleaning apparatus, when the rinsing is performed by the cleaning means, the control means controls the water supply means so as to add water to the cleaning tank based on the signal from the molecular detection device. Therefore, when the concentration of the detergent is high and rinsing is not sufficient, rinsing is performed by adding water until it can be determined that the rinsing has been sufficiently performed. As a result, it is possible to provide a cleaning device that can perform sufficient rinsing.

  More preferably, the molecular detection device further includes a protective layer formed between the metal layer and the hydrophobic layer for protecting the metal layer.

  According to this cleaning device, there is a protective layer for protecting the metal layer between the metal layer and the hydrophobic layer. Therefore, it is possible to provide a cleaning device that can prevent the metal layer from peeling and oxidizing.

  Preferably, in the hydrophobic layer, an organic molecule containing a substance selected from the group consisting of an alkyl group, an alkylbenzene group, an alkylnaltalene group, a perfluoroalkyl group, a polypropylene oxide group, and a polysiloxane group is chemically bonded to the protective layer. It is formed by things.

  According to this cleaning device, amphiphilic molecules are efficiently adsorbed to the hydrophobic layer. Therefore, the detection sensitivity is improved.

  Preferably, the protective layer is formed of a material selected from the group consisting of silicon oxide, titanium oxide, aluminum oxide, and zinc oxide.

  According to this cleaning apparatus, the protective layer is formed of any one of silicon oxide, titanium oxide, aluminum oxide, and zinc oxide. Since the protective layer is an oxide, chemical coating of the hydrophobic layer on the metal layer is facilitated. As a result, the strength of the hydrophobic layer increases.

  Preferably, the metal layer is formed of a material selected from the group consisting of gold, silver, platinum, and aluminum.

  According to this cleaning apparatus, the metal layer is formed of any one of gold, silver, platinum, and aluminum. Therefore, surface plasmon resonance can be excited efficiently. As a result, amphiphilic molecules can be detected with high sensitivity.

  Preferably, the cleaning device is an automatic washing machine, and the cleaning means includes means for cleaning the clothes with the cleaning liquid in the cleaning tank by rotating the cleaning tank around a predetermined rotation axis.

  According to this cleaning device, the cleaning tank rotates around a predetermined rotation axis. Accordingly, if the cleaning liquid and the clothes are placed in the cleaning tank, the clothes can be cleaned.

  Preferably, the cleaning device is a dishwasher, and the cleaning means is disposed in the cleaning tank, and the cleaning liquid stored in a predetermined part in the cleaning tank is ejected to an object to be cleaned disposed in the cleaning tank. Including a cleaning liquid nozzle.

  According to this cleaning apparatus, the cleaning liquid stored in a predetermined part in the cleaning tank is sprayed onto the object to be cleaned arranged in the cleaning tank. Therefore, if the object to be cleaned is placed in the cleaning tank, It is possible to remove the dirt on the washing object.

  The molecular detection device included in the cleaning device according to the present invention measures the concentration of the ionic surfactant in the cleaning solution by directly adsorbing it to the hydrophobic membrane, so that the concentration can be measured without being affected by counter ions. . Further, even in the case of a nonionic surfactant, the nonionic surfactant is directly adsorbed on the hydrophobic membrane, so that the concentration can be measured without being influenced by counter ions. As a result, it is possible to provide a cleaning apparatus that can more accurately detect the concentration of detergent molecules contained in the solution and thereby achieve a higher cleaning effect and rinsing effect than those that measure electrical conductivity. .

  Further, according to the cleaning apparatus of the present invention, when the cleaning by the cleaning means is executed, the control means controls the detergent supply means so as to add the detergent to the cleaning tank based on the signal from the molecular detection device. Therefore, when the concentration of the detergent is low and not suitable for washing, the detergent concentration can be increased to a concentration suitable for washing. As a result, it is possible to provide a cleaning apparatus capable of performing appropriate cleaning with a sufficient detergent concentration. Further, when rinsing is performed by the cleaning means, the control means controls the water supply means so as to add water to the cleaning tank based on a signal from the molecular detection device. Therefore, when the concentration of the detergent is high and rinsing is not sufficient, rinsing is performed by adding water until it can be determined that the rinsing has been sufficiently performed. As a result, it is possible to provide a cleaning device that can perform sufficient rinsing.

  According to this cleaning device, there is a protective layer for protecting the metal layer between the metal layer and the hydrophobic layer. Therefore, peeling and oxidation of the metal layer can be prevented. In addition, amphiphilic molecules are efficiently adsorbed to the hydrophobic layer. Therefore, the detection sensitivity is improved. Furthermore, the protective layer is formed of any one of silicon oxide, titanium oxide, aluminum oxide, and zinc oxide. Since the protective layer is an oxide, chemical coating of the hydrophobic layer on the metal layer is facilitated. As a result, the strength of the hydrophobic layer increases. In addition, the metal layer is formed of any one of gold, silver, platinum, and aluminum. Therefore, surface plasmon resonance can be excited efficiently. As a result, amphiphilic molecules can be detected with high sensitivity.

[First Embodiment]
<Configuration>
FIG. 1 shows a cross-sectional view of a configuration of an automatic washing machine 30 that is a cleaning device according to a first embodiment of the present invention. Referring to FIG. 1, an automatic washing machine 30 is disposed inside a water receiving tub 40 having a hollow cylindrical shape with an open top for storing water during washing, and is to be cleaned. A washing / dehydrating tub 42 as a cleaning means having a hollow cylindrical shape with an opening at the top, in which drain holes 60 to 70 for dehydration are perforated, for storing laundry and dehydrating The rotating shaft 44 attached to the bottom bottom center of the washing and dewatering tub 42, the motor 48 provided below the water receiving tub 40 so as to provide power for rotating the rotating shaft 44, and the power of the motor 48 are And a belt 46 for transmitting to the rotating shaft 44 and rotating the rotating shaft 44. Since the washing / dehydrating tub 42 is rotated by the motor 48 via the rotating shaft 44, the laundry, which is the object to be cleaned, can be cleaned by the washing water inside.

  The automatic washing machine 30 is further included in the drainage valve 50 as drainage means for draining the water drained from the drain holes 60 to 70 and collected in the water receiving tank 40, and the water collected in the water receiving tank 40. A detergent sensor 52 which is a molecular detection device for measuring the concentration of the detergent to be used using surface plasmon resonance and outputting the measurement result as an electrical signal, and a signal representing the detergent concentration measurement result output by the detergent sensor 52 And a control circuit 54 as a control means including a processor for performing various processes for receiving and adjusting the detergent concentration.

  The principle of surface plasmon resonance will be described later.

  The automatic washing machine 30 is further controlled by a control circuit 54 and controlled by the detergent injection device 56 as a detergent supply means for injecting the detergent into the washing and dewatering tub 42, and also by the control circuit 54. And a water injection valve 58 as water supply means for injecting water into the water.

  FIG. 2 is a flowchart showing details of a control structure of a program for controlling the washing process by the automatic washing machine 30 shown in FIG. Referring to FIG. 2, in step 150, water injection and detergent injection are performed. In step 152, the motor 48 (see FIG. 1) is rotated and washing is started. At this time, a timer (not shown) for measuring the washing time is also started.

  In step 154, processing for determining whether or not the time for washing by the timer is within a specified time is performed. If it is within the specified time, the process proceeds to step 156. When the specified time expires, the process proceeds to step 164.

  Once the water and detergent have been agitated to some extent, at step 156, the detergent concentration is detected by the detergent sensor 52 (see FIG. 1).

  In step 158, processing is performed by the detergent sensor 52 to determine whether or not the detergent concentration is equal to or higher than a prescribed first threshold value suitable for washing. If it is equal to or greater than the first threshold value, the process proceeds to step 162, and if it is less than the first threshold value, the process proceeds to step 160. In step 160, a process in which an appropriate amount of detergent is injected by the detergent injection device 56 according to the concentration is performed. Thereafter, the processing returns to step 154 and the subsequent processing is repeated. In step 162, a washing operation is performed for a certain period of time, and then the process returns to step 154.

  In step 164, processing for ending the washing operation is performed. In step 166, drainage from the drain valve 50, dehydration, and water injection from the water injection valve 58 are performed. In step 168, rinsing is performed for a certain time. In step 170, the detergent sensor 52 performs the detergent concentration detection process again.

  In step 172, a process for determining whether or not the concentration of the detergent measured by the detergent sensor 52 is equal to or less than a predetermined second threshold value is performed. If the detergent concentration exceeds the second threshold value, the process returns to step 166 and the subsequent processing is repeated. If the detergent concentration is equal to or lower than the second threshold value, the process proceeds to step 174. In step 174, drainage and dewatering from the drain valve 50 are performed. Here, the rotation of the motor 48 is further stopped, and the washing process is terminated.

  FIG. 3 is a sectional view showing the internal configuration of the detergent sensor 52 and the configuration of the detection space 102 adjacent to the detergent sensor. In this figure, the detergent sensor 52 is shown by rotating the detergent sensor 52 shown in FIG. 1 by 90 degrees clockwise.

  Referring to FIG. 3, the detergent sensor 52 is arranged so that the total reflection surface faces the detection space 102. The prism 84 as a transparent substrate and the incident light formed on the total reflection surface of the prism 84 are formed. A light source 80 disposed at a position on the opposite side of the detection space 102 so that light is incident on the total reflection condition under the total reflection condition with respect to the total reflection surface of the metal layer 86 and the prism 84, and a light source And a condensing lens 82 for condensing incident light emitted from 80 on the total reflection surface of the prism 84.

  The detergent sensor 52 further includes a protective layer 88 formed on the metal layer 86 in order to prevent peeling and oxidation of the metal layer 86, and a parent formed on the protective layer 88 and existing in water in the detection space 102. Reflected light from the metal layer 86 having a hydrophobic layer 90 for adsorbing the hydrophobic group of the medicinal molecule, a light receiving region divided into a first portion 94 and a second portion 96, and entering each portion For detecting the intensity of the signal and converting it into a voltage signal, and a voltage signal from the first portion 94 and the second portion 96 and receiving the difference as a sensor output 100 to the outside. And a dynamic amplifier 98.

  The opening of the detection space 102 facing the water receiving tub 40 is used to appropriately detect the detergent molecules by suppressing the water flow of the washing machine so that the water flow does not disturb the adsorption of the detergent molecules and the hydrophobic layer 90. Eaves 104 and 106 are formed.

<Detection method of detergent concentration>
With reference to FIG. 4, the surface plasmon resonance which is the principle of detection of the detergent concentration by the detergent sensor 52 will be described.

  When incident light enters the metal layer 86 that is a conductor at a predetermined incident angle, a surface plasmon wave is excited in the metal layer 86. Normally, when the metal layer 86 is irradiated with laser light and the component parallel to the metal layer 86 of the wave number vector of the laser light coincides with the wave number of the surface plasmon wave, resonance occurs, and a part of the energy of the incident light is Used to excite surface plasmon waves and attenuates reflected light. This phenomenon is surface plasmon resonance.

  Surface plasmon excitation conditions vary greatly depending on physical properties in the vicinity of the interface of the metal layer 86, such as refractive index or dielectric constant. For example, even if there is a slight change in the refractive index of the metal layer 86, the resonance condition changes greatly, and the surface plasmon excitation condition changes. By the way, it is known that when a substance to be detected is adsorbed on the hydrophobic layer 90, the refractive index at the interface of the metal layer 86 changes. As a result, when the substance to be detected is adsorbed on the hydrophobic layer 90, the refractive index changes at the interface of the metal layer 86, and the surface plasmon excitation condition changes greatly. Therefore, the substance can be detected with high sensitivity. Of the change in the excitation condition of the surface plasmon resonance due to the adsorption of the substance to be measured, the incident angle at which the surface plasmon resonance occurs can be detected by measuring the reflected light intensity for each incident angle with the photodetector 92. This is the principle of a detection method using general surface plasmon resonance. Even when the protective layer 88 is formed between the metal layer 86 and the hydrophobic layer 90 as in the present embodiment, the near-field excited by surface plasmon resonance is reduced by reducing the thickness of the protective layer 88. Adsorption of a substance on the hydrophobic layer 90 can be detected by making it sufficiently reach the hydrophobic layer 90. The film thickness of the protective layer 88 will be described later.

  Next, a method for detecting the detergent concentration using the above-described plasmon resonance will be described. The detergent molecule is amphiphilic. Therefore, referring to FIG. 4, micelles 110 and 112 in which a plurality of detergent molecules are aggregated are generated in the water in the laundry layer into which the detergent molecules are introduced. In micelles 110 and 112, the detergent molecules are aggregated so that the hydrophobic groups of the detergent molecules face inward and the hydrophilic groups face outward. It is known that for the formation of micelles 110 and 112, the detergent concentration must be above a certain concentration. The detergent concentration at which the micelles 110 and 112 are formed in this way is called the critical micelle concentration.

  The detergent molecule is amphiphilic and has a hydrophobic group 118 and a hydrophilic group 116 as shown in FIG. The hydrophobic group 118 may be adsorbed on the hydrophobic layer 90.

  The detergent has cleaning ability when the detergent concentration is above the critical micelle concentration. At this time, the amount of the detergent molecules 114 adsorbed on the hydrophobic layer 90 is saturated. When the detergent concentration falls below the critical micelle concentration, the micelles 110 and 112 disappear, a part of the detergent molecules 114 adsorbed on the hydrophobic layer 90 is desorbed, and the number of detergent molecules adsorbed on the hydrophobic layer 90 decreases. Accordingly, the amount of the detergent molecules 114 adsorbed on the hydrophobic layer 90 depends on the concentration of the detergent molecules in the water.

  That is, as the concentration of the detergent increases, the adsorption of the detergent molecules 114 to the hydrophobic layer 90 proceeds, and the adsorption amount is saturated near the critical micelle concentration. On the contrary, when the concentration of the detergent molecules 114 becomes lower than the critical micelle concentration, the desorption of the detergent molecules 114 proceeds from the hydrophobic layer 90, and the amount of the detergent molecules 114 adsorbed on the hydrophobic layer 90 decreases. In this way, adsorption and desorption occur according to the detergent concentration in the water, and an equilibrium state is reached. As a result, the amount of the hydrophobic groups 118 of the detergent molecules 114 adsorbed on the hydrophobic layer 90 depends on the concentration of the detergent in water, and the amount of adsorption increases when the concentration is high. When the concentration is low, the amount of adsorption decreases.

  This concentration dependency is a phenomenon that occurs because the detergent molecules 114 have amphipathic properties. Such a phenomenon does not occur in lipophilic molecules having no amphiphilic properties such as physiologically active substances and oils. Similarly, even hydrophilic molecules do not show concentration dependence. When the hydrophobic group 118 of the detergent molecule 114 is adsorbed to the hydrophobic layer 90, the hydrophilic group 116 is turned into water.

  If the concentration is higher than the critical micelle concentration, the hydrophobic groups 118 of the detergent molecules 114 are adsorbed on the particles such as oil and surround the particles, and the hydrophilic groups 116 are directed outward. Therefore, in this case, particles such as oil do not adsorb on the hydrophobic layer 90 of the detergent sensor 52.

  5 and 6 show examples of reflected light intensity patterns seen on the detection surface of the photodetector 92. FIG. FIG. 5 shows an intensity pattern when the detergent molecules 114 (see FIG. 4) are not adsorbed on the hydrophobic layer 90. The entire hatched portion 120 reflects the shape of the reflected light beam. In the left half, incident light is absorbed by surface plasmon resonance, and a dark line 124 in which the intensity of reflected light is reduced is generated. The reason why dark lines are partially generated in the intensity pattern is as follows.

  In FIG. 4, incident light is converged by the condenser lens 82 and applied to the metal layer 86. The angle of the incident light on the metal layer 86 extends from the angle of the center of the incident light to an angle range corresponding to the convergence. This means that the light spreads on both the positive and negative sides by an angle corresponding to the numerical aperture of the lens from the angle of the center of the incident light.

  Within that angular range, only a limited angle can excite surface plasmon resonance. Absorption of incident light occurs only at this excitable angle. Accordingly, the angle at which the absorption occurs within the angle range of the incident light is only a certain part, and only the incident light at the remaining angle at which no absorption occurs reflects to the photodetector 92 side.

  Therefore, on the photodetector 92, the reflected light cannot be detected at the angle at which the surface plasmon is excited, and only the reflected light at other angles can be detected. Therefore, a portion corresponding to the angle at which the surface plasmon is excited appears as a dark line in the intensity pattern on the photodetector 92.

  Here, as the detergent concentration increases, the detergent molecules adsorbed on the hydrophobic layer 90 also increase. When detergent molecules adsorbed on the hydrophobic layer 90 increase, the optical conditions such as the refractive index at the interface of the metal layer 86 change, and the incident angle at which surface plasmon resonance can be excited increases. Then, the dark line 124 in FIG. 5 gradually moves to the right side (the side on which the angle of reflected light increases), and shows a pattern like the dark line 130 shown in FIG. That is, the dark line gradually moves from the region of the first portion 94 (see FIG. 4) to the region of the second portion 96.

  By outputting the difference between the detection values of the first portion 94 and the second portion 96 from the differential amplifier 98, the movement of the dark line can be electrically measured. FIG. 7 shows a curve 140 showing the relationship between the detergent concentration at this time and the sensor output 100 which is the output of the differential amplifier 98. As shown in this figure, the sensor output voltage increases as the detergent concentration increases.

<Operation>
The operation of the automatic washing machine 30 will be described with reference to FIG. 1, FIG. 3, and FIG. First, when the laundry to be cleaned is put into the washing and dewatering tank 42 (see FIG. 1), detergent is injected from the detergent injection device 56 and water is injected from the water injection valve 58. The power of the motor 48 is transmitted to the rotating shaft 44 via the belt 46, and the washing and dewatering tub 42 rotates. The water stored in the washing and dewatering tub 42 flows into the water receiving tub 40 through the drain holes 60 to 70.

  At this time, water mixed with detergent flows into the detection space 102 (see FIG. 3) attached to the side surface of the water receiving tank 40. A large number of detergent molecules form micelles 110 and 112 (see FIG. 4) in water, but the hydrophobic groups 118 of the detergent molecules 114 that did not form the micelles 110 and 112 are adsorbed to the hydrophobic layer 90.

  Here, the incident light emitted from the light source 80 included in the detergent sensor 52 is collected by the condenser lens 82 and applied to the metal layer 86 formed on the prism 84. A hydrophobic layer 90 is formed on the surface of the metal layer 86 with a protective layer 88 interposed therebetween. When incident light is incident on the metal layer 86 at a predetermined incident angle, surface plasmons are excited in the metal layer 86. The angle at which the surface plasmons are excited varies according to the amount of detergent molecules 114 adsorbed on the hydrophobic layer 90. The reflected light from the metal layer 86 is converted into two kinds of voltage signals by the photodetector 92 and supplied to the differential amplifier 98. The value of this voltage signal represents the intensity of the reflected light incident on the detection surface of the light receiver. Therefore, the output voltage of the detection surface where the dark line is generated by the surface plasmon is lower than that of the other region. The differential amplifier 98 takes a difference between two kinds of voltages. Using this voltage difference, the differential amplifier 98 measures the reflected light intensity.

  The differential amplifier 98 transmits a signal representing the measurement result to the control circuit 54 (see FIG. 1). In accordance with the measurement result transmitted from the detergent sensor 52, the control circuit 54 controls the detergent injection device 56 to inject further detergent if the detergent concentration is too low, and further controls the water injection valve 58 if the detergent concentration is too high. Inject water.

  When washing using the detergent at an appropriate detergent concentration is completed and dehydration is completed, drainage is performed from the drain valve 50 under the control of the control circuit 54. Thereafter, the automatic washing machine 30 performs a rinsing operation. The details of the rinsing operation are basically the same as the washing using the detergent, except that the detergent is not injected, and therefore the description will not be repeated here.

  Also in the case of rinsing, rinse water flows into the detergent sensor 52 and the detergent concentration is measured. The measured detergent concentration measurement result signal is transmitted to the control circuit 54. If the detergent concentration is sufficiently low, the washing is terminated after rinsing and dehydration. If the detergent concentration is too high, the control circuit 54 controls the water injection valve 58 to inject water to perform rinsing and dehydration again.

<Production method>
Below, the concrete component of the detergent sensor 52 is shown. The light source 80 is a semiconductor laser having a wavelength of 635 nm, the numerical aperture of the condenser lens 82 is 0.05, the material of the prism 84 is Lumicera (registered trademark, manufactured by Murata Manufacturing Co., Ltd., refractive index 2.08), and the metal layer 86 is 50 nm thick. Gold and the protective layer 88 are made of 2 nm thick silicon oxide.

  The incident angle at the center of the incident light is 45 degrees, and the incident angle at the beam end is within a range of ± 3 to 4 degrees due to condensing. This condition is determined according to one of the conditions for efficiently exciting the surface plasmon resonance. When the above wavelength and the refractive index of the prism are fixed, it is preferable that the metal layer 86 has a thickness of 10 to 100 nm and the protective layer 88 has a thickness of 1 to 20 nm.

  The manufacturing method of the hydrophobic layer 90 is as follows. Put 0.064 g of octadecyltriethoxysilane in a container and dissolve in 5.950 g of toluene (1 wt% solution). Further, the high refractive index prism is put in the liquid and stirred at room temperature for 30 minutes. Thereafter, the substrate is taken out and dried at room temperature for 23 hours. After drying, the surface is washed with acetone. As a result, octadecylsilane can be strongly bonded onto the protective layer 88 made of silicon oxide, and a strong hydrophobic layer 90 is formed.

  According to the automatic washing machine 30 according to the present embodiment, since the detergent concentration can be detected by the detergent sensor 53, automatically when the surfactant concentration in the cleaning liquid is lower than the first threshold value. The detergent concentration required for cleaning can be achieved by adding detergent. Further, when rinsing, if the surfactant concentration in the cleaning liquid is higher than the second threshold value, the surfactant concentration can be sufficiently lowered by automatically injecting water.

  Further, the detergent molecules 114 (see FIG. 4) are reversibly adsorbed and separated from the hydrophobic layer 90 according to the concentration of the detergent in water. Therefore, it is not necessary to make the detection device disposable, and it can be used repeatedly.

  Furthermore, a drug or the like that removes the detergent molecules 114 is unnecessary. Therefore, it is possible to realize a popular detergent detection device with a low environmental load.

  There is a protective layer for protecting the metal layer between the metal layer and the hydrophobic layer. Therefore, it is possible to realize a molecular detection device that can prevent peeling and oxidation of the metal layer.

  The material of the metal layer 86 may be any of silver, platinum, and aluminum in addition to gold.

  Further, the protective layer 88 may be any of titanium oxide, aluminum oxide, and zinc oxide in addition to silicon oxide.

  The octadecyltriethoxysilane used as the material for forming the hydrophobic layer 90 includes a linear alkyl group in which 18 carbons are linearly bonded as a hydrophobic group, but in addition, a branched alkyl group, alkylbenzene. It may be an organic molecule containing any one of a group, an alkylnaltalene group, a perfluoroalkyl group, a polypropylene oxide group, and a polysiloxane group.

  In addition, the reaction conditions for manufacturing the hydrophobic layer 90 described in the present embodiment are an example. It is necessary to change the concentration of the silane coupling agent, the type of the solvent, the stirring time, the drying time, and the cleaning solvent depending on the type of substituent to be mounted on the hydrophobic layer 90.

[Second Embodiment]
<Configuration>
In FIG. 8, the structure of the automatic washing machine 150 which is a washing | cleaning apparatus based on the 2nd Embodiment of this invention is shown with sectional drawing. The automatic washing machine 150 is a washing machine for washing heavy dirt such as shoes and work clothes. In FIG. 8, the same components as those in the first embodiment are denoted by the same reference numerals, and the same names are used. Their functions are also the same. Therefore, description thereof will not be repeated.

  Referring to FIG. 8, this automatic washing machine 150 is provided at the lower part of the inner side surface of the water receiving tub 40 in addition to the configuration of the automatic washing machine 30 according to the first embodiment shown in FIG. It further includes a turbidimeter 152 for measuring the turbidity of water caused by dirt such as mud. The automatic washing machine 150 further receives outputs of the turbidimeter 152 and the detergent sensor 52 instead of the control circuit 54 of the automatic washing machine 30 shown in FIG. 1, and the drain valve 50 and the detergent injection device 56 according to the outputs. A control circuit 154 including a processor for controlling the water injection valve 58 and the motor 48.

  FIG. 9 is a flowchart showing details of a control structure of a program executed by the control circuit 154 for controlling the washing process by the automatic washing machine 150 shown in FIG. Referring to FIG. 9, in step 260, water is injected, and motor 48 (see FIG. 8) is rotated to perform washing. When the water is stirred to some extent, the turbidity of the water is detected using the turbidimeter 152 in step 262.

  In step 264, a process for determining whether the turbidity of water is equal to or less than a prescribed value suitable for washing using a detergent is performed. If it is equal to or less than the specified value, the process proceeds to step 268, and if it is higher than the specified value, the process proceeds to step 266.

  In step 266, the process of draining the water in the washing tub 40 from the drain valve 50 is performed, and the process returns to step 260.

  In step 268, water injection and detergent injection are performed. In step 270, the motor 48 is rotated to perform washing.

  In step 272, processing for determining whether or not the time from the start of washing is within a specified time is performed. If it is within the specified time, the process proceeds to step 274, and if longer than the specified time, the process proceeds to step 282.

  Once the water and detergent have been agitated to some extent, the detergent concentration is detected by the detergent sensor 52 at step 274.

  In step 276, processing is performed by the detergent sensor 52 to determine whether or not the concentration of the detergent is equal to or higher than a predetermined first threshold value suitable for washing. If it is equal to or greater than the first threshold value, the process proceeds to step 278, and if it is less than the first threshold value, the process proceeds to step 280. In step 280, a process is performed in which an appropriate amount of detergent is further injected by the detergent injection device 56 in accordance with the concentration. Thereafter, the processing returns to step 272 and the subsequent processing is repeated.

  In step 278, a process of continuing the washing operation for a predetermined time is performed, and then the process returns to step 272. In step 282, processing for ending the washing operation is performed.

  In step 284, drainage from the drain valve 50, dehydration, and water injection from the water injection valve 58 are performed. In step 286, rinsing is performed. In step 288, the detergent sensor 52 performs the detergent concentration detection process again.

  In step 290, processing for determining whether or not the concentration of the detergent measured by the detergent sensor 52 is equal to or less than a predetermined second threshold value is performed. If the detergent concentration exceeds the second threshold value, the process returns to step 284 and the subsequent processing is repeated. If the detergent concentration is less than or equal to the second threshold, the process proceeds to step 292. In step 292, drainage and dewatering from the drain valve 50 are performed. Here, the rotation of the motor 48 is further stopped, and the washing process is terminated.

<Operation>
The operations of the automatic washing machine 150 according to the present embodiment and the automatic washing machine 30 according to the first embodiment are almost the same. However, the automatic washing machine 150 according to the present embodiment includes a turbidimeter 152 that detects the turbidity of the washing water. Therefore, dirt such as mud contained in the water is detected from the turbidity of the washing water before washing using the detergent, and the result is given to the control circuit 154. The control circuit 154 given the result controls the operation of the washing machine based on the result. Specifically, if the turbidity is larger than the reference value, control is performed such that drainage and reinjection are performed and washing is performed again. If the turbidity is below the reference value, control is performed so that water injection and detergent injection are performed. Since other operations are similar to those described in the first embodiment, description thereof will not be repeated. As a configuration of the turbidimeter, for example, a turbidimeter using an optical sensor disclosed in JP-A-8-141273 can be used.

  According to the automatic washing machine 150 according to the present embodiment, even if a lot of dirt due to mud such as shoes and work clothes adheres, mud dirt is removed to some extent by detecting the turbidity by the turbidimeter 152. Can be washed with detergent. Therefore, it can wash efficiently.

[Third Embodiment]
<Configuration>
FIG. 10 is a cross-sectional view showing the configuration of a dishwasher 218 that is a cleaning device according to the third embodiment of the present invention. Referring to FIG. 10, dishwasher 218 defines a space for storing and cleaning dishes therein, and has a housing 200 having an opening on the front (left side in FIG. 10), and a housing. It includes a door 204 whose posture can be changed between a state of covering the opening of the body 200 and a state of exposing the opening.

  In the space inside the housing 200, tableware which is an object to be cleaned is accommodated, and a cleaning tank 202 as a cleaning means for cleaning the tableware using cleaning water containing a detergent, and the cleaning tank 202 The washing water used for washing is collected in a lower part of the water and is roughly divided into a detection space 203 for detecting the detergent concentration.

  The door 204 is formed with a translucent portion 206 for efficiently collecting external light into the cleaning tank 202, and a handle 208 used for opening and closing is provided at the front portion of the door 204. Yes. Further, a seal member 210 for sealing the cleaning tank 202 from the outside is provided between the lower portion of the door 204 and the opening of the housing 200.

  The dishwasher 218 further includes a support arm 212 that supports the door 204 so as to be rotatable up and down within a rotation range of 90 degrees around a fulcrum provided on the side surface of the housing 200, and tableware provided in the washing tub 202. A basket 214, a water supply means for injecting cleaning water from the lower part to the upper part in the cleaning tank 202, and a cleaning nozzle 216 as a detergent supply means, are provided adjacent to the detection space 203, and are stored in the detection space 203. A detergent sensor 52 which is a molecular detection device for detecting the detergent concentration of the washing water, and a water injection device and a detergent injection device (not shown) for supplying water and detergent to the detection space 203, respectively.

  The detergent sensor 52 is exactly the same as the detergent sensor 52 shown in FIG. 3, and detects the detergent concentration using surface plasmon resonance.

  FIG. 11 is a flowchart showing a control structure of a program for controlling the dishwasher 218 shown in FIG. Referring to FIG. 11, in step 220, cleaning water containing the detergent once injected into detection space 203 is jetted from cleaning nozzle 216. In step 222, washing is started by spraying washing water containing detergent from the washing nozzle 216 to the tableware or the like. At this time, a timer (not shown) for measuring the washing time is also started.

  In step 224, processing for determining whether or not the time for washing by the timer is within a specified time is performed. If it is within the specified time, the process proceeds to step 226. When the specified time expires, the process proceeds to step 234.

  When the washing water containing the detergent circulates in the washing tank 202 and flows again into the detection space 203, the detergent concentration is detected by the detergent sensor 52 in step 226.

  In step 228, processing is performed by the detergent sensor 52 to determine whether or not the concentration of the detergent is equal to or higher than a predetermined first threshold value suitable for cleaning. If it is equal to or greater than the first threshold value, the process proceeds to step 230, and if it is less than the first threshold value, the process proceeds to step 232. In step 232, processing is performed in which an appropriate amount of detergent is further injected into the detection space 203 from a detergent injection device (not shown) according to the concentration. Thereafter, the processing returns to step 224 and the subsequent processing is repeated. In step 230, a washing operation is performed for a predetermined time, and then the process returns to step 224.

  In step 234, processing for ending the washing operation is performed. In step 236, drainage and water injection into the detection space 203 are performed. In step 238, rinsing is performed with water ejected from the cleaning nozzle 216 for a certain period of time. In step 240, the detergent concentration of the rinse water flowing into the detection space 203 is again detected by the detergent sensor 52.

  In step 242, a process for determining whether or not the concentration of the detergent measured by the detergent sensor 52 is equal to or less than a predetermined second threshold value is performed. If the detergent concentration exceeds the second threshold value, the process returns to step 236 and the subsequent processing is repeated. If the detergent concentration is equal to or lower than the second threshold value, the process proceeds to step 244. In step 244, the rinsing water is discharged.

  In step 246, the process of drying the tableware is performed, and the cleaning process is terminated.

<Operation>
The operation of the dishwasher 218 will be described with reference to FIG. First, when a washing object such as tableware is put in the tableware basket 214, detergent and water are injected into the detection space 203 from a detergent injection device and a water injection device (not shown). Water containing the detergent injected into the detection space 203 is sprayed from the cleaning nozzle 216 into the cleaning tank 202. The water containing the detergent sprayed into the cleaning tank 202 circulates in the cleaning tank 202 and flows into the detection space 203 again.

  The detergent concentration of the wash water flowing into the detection space 203 is detected by the detergent sensor 52, but the detection operation here is the same as the detection operation of the detergent sensor 52 according to the first embodiment, so the description will not be repeated. .

  The differential amplifier 98 transmits a signal representing the measurement result to a control circuit (not shown). According to the measurement result transmitted from the detergent sensor 52, the control circuit causes the detergent to be further injected into the detection space 203 and sprayed from the washing nozzle 216 into the washing tank 202 if the detergent concentration is too low. If the detergent concentration is too high, water is further injected into the detection space 203 and water is jetted from the cleaning nozzle 216 to the cleaning tank 202.

  When cleaning with the detergent is completed at an appropriate detergent concentration, drainage is performed under the control of the control circuit. Thereafter, the dishwasher 218 performs a rinsing operation. The details of the rinsing operation are the same as cleaning using a detergent, except that the water does not contain a detergent, and therefore the description will not be repeated here.

  Also in the case of rinsing, rinse water flows into the detection space 203 and the detergent concentration is measured by the detergent sensor 52. The measured detergent concentration measurement result signal is transmitted to the control circuit. If the detergent concentration is sufficiently low, the washing is finished after rinsing and draining. If the detergent concentration is too high, the control circuit sprays water from the washing nozzle 216 through the detection space 203 and again rinses and drains. If the detergent concentration at the time of rinsing and draining becomes appropriate, the tableware and the like are dried, and the cleaning process is completed.

  According to the dishwasher 218 according to the present embodiment, since the detergent concentration can be detected by the detergent sensor 52, when the surfactant concentration in the washing liquid is lower than the first threshold value, it is automatically set. The detergent concentration required for cleaning can be achieved by adding detergent. Further, when rinsing, if the surfactant concentration in the cleaning liquid is higher than the second threshold value, the surfactant concentration can be sufficiently lowered by automatically injecting water.

  According to the detergent sensor 52 included in the automatic washing machines 30 and 150 and the dishwasher 218 according to the present invention, the incident angle of light at which surface plasmon resonance occurs at the interface of the metal layer 86 is a detergent molecule adsorbed on the surface of the hydrophobic layer. Depends on the amount of adsorption. The amount of adsorption of the detergent molecules depends on the concentration of the detergent molecules in the water. Therefore, the incident angle of light at which surface plasmon resonance occurs in the metal layer 86 depends on the concentration of detergent molecules in water. As a result, the detergent concentration can be measured with high sensitivity by the amount of reflected light.

  The embodiment disclosed herein is merely an example, and the present invention is not limited to the above-described embodiment. The scope of the present invention is indicated by each claim in the claims after taking into account the description of the detailed description of the invention, and all modifications within the meaning and scope equivalent to the wording described therein are intended. Including.

2 is a view showing a cross section of an automatic washing machine 30. FIG. It is a flowchart which shows the control structure of the program for control of the automatic washing machine 30 shown in FIG. It is a figure which shows the internal structure of the detergent sensor 52, and the structure of the detection space 102 adjacent to the detergent sensor 52 in a cross section. It is a figure which shows the detection principle of the detergent density | concentration by the detergent sensor. It is a figure which shows the example of the intensity pattern of the reflected light seen on the detection surface of the photodetector. It is a figure which shows the example of the intensity pattern of the reflected light seen on the detection surface of the photodetector. It is a graph which shows the relationship between the detergent density | concentration when the movement of a dark line is electrically measured, and the sensor output. It is a figure which shows the cross section of the automatic washing machine 150. FIG. It is a flowchart which shows the control structure of the program for control of the automatic washing machine 150 shown in FIG. It is a figure which shows the cross section of the dishwasher 218. FIG. It is a flowchart which shows the control structure of the program for control of the dishwasher 218 shown in FIG.

Explanation of symbols

30 and 150 automatic washing machine, 40 water receiving tub, 42 washing and dewatering tub, 44 rotating shaft, 46 belt, 48 motor, 50 drain valve, 52 detergent sensor, 54 control circuit, 56 detergent injection device, 60-70 drain Hole, 80 Light source, 82 Condensing lens, 84 Prism, 86 Metal layer, 88 Protective layer, 90 Hydrophobic layer, 92 Photo detector, 94 First part, 96 Second part, 98 Differential amplifier, 100 Sensor output , 104 and 106 eaves part, 110 and 112 micelle, 114 detergent molecule, 116 hydrophilic group, 118 hydrophobic group, 124, 130 dark line, 200 housing, 202 washing tank, 203 detection space, 204 door, 206 translucent part, 208 Handle, 210 seal member, 212 support arm, 214 tableware basket, 216 washing nozzle, 218 dishwasher

Claims (9)

A washing tank;
Water supply means for supplying water to the cleaning tank;
Detergent supply means for supplying detergent to the washing tank;
A cleaning means for cleaning the object to be cleaned disposed in the cleaning tank using a cleaning liquid obtained by mixing water supplied by the water supply means and a detergent supplied by the detergent supply means;
A molecular detector for detecting the concentration of the detergent in the cleaning liquid in the cleaning tank;
Discharging means for discharging the cleaning liquid in the cleaning tank;
Control means for controlling the water supply means, the detergent supply means, the discharge means, and the cleaning means based on the detection result from the molecular detection device,
The molecular detection device is a molecular detection device that detects amphiphilic molecules using surface plasmon resonance,
A transparent substrate having a first reflective surface;
A metal layer formed on the first reflective surface of the transparent substrate;
A light source disposed on the opposite side of the metal layer with respect to the first reflective surface so that light is incident on the first reflective surface under total reflection conditions;
A hydrophobic layer formed on the metal layer;
Detecting means for detecting a change in the position of a dark line caused by surface plasmon resonance in the reflected light emitted from the light source and reflected by the reflecting surface;
The molecular detection device is a cleaning device arranged such that the hydrophobic layer faces a portion of the cleaning tank where cleaning water is stored.   In response to the determination that the concentration of the detergent is less than a predetermined first threshold, based on a signal from the molecular detection device when the cleaning unit performs the cleaning, The cleaning apparatus according to claim 1, wherein the detergent supply unit is controlled to add a detergent to the cleaning tank.   In response to the determination that the concentration of the detergent is equal to or higher than a predetermined second threshold, based on the signal from the molecular detection device, when the rinsing is performed by the cleaning unit, The cleaning apparatus according to claim 1, wherein the water supply unit is controlled to add water to the cleaning tank.   The cleaning apparatus according to any one of claims 1 to 3, wherein the molecular detection device further includes a protective layer formed between the metal layer and the hydrophobic layer for protecting the metal layer. .   In the hydrophobic layer, an organic molecule containing a substance selected from the group consisting of an alkyl group, an alkylbenzene group, an alkylnaltalene group, a perfluoroalkyl group, a polypropylene oxide group, and a polysiloxane group is chemically bonded to the protective layer. The cleaning apparatus according to any one of claims 1 to 4, wherein the cleaning apparatus is formed by:   The cleaning device according to claim 4 or 5, wherein the protective layer is formed of a material selected from the group consisting of silicon oxide, titanium oxide, aluminum oxide, and zinc oxide.   The said metal layer is a washing | cleaning apparatus in any one of Claims 1-6 formed with the material chosen from the group which consists of gold | metal | money, silver, platinum, and aluminum. The washing device is an automatic washing machine;
The said washing | cleaning means contains a means for washing | cleaning clothes with the washing | cleaning liquid in the said washing tank by rotating the said washing tank around a predetermined | prescribed rotation axis | shaft. Cleaning device. The washing device is a dishwasher;
The cleaning means includes a cleaning liquid nozzle that is disposed in the cleaning tank and ejects a cleaning liquid stored in a predetermined portion of the cleaning tank to an object to be cleaned disposed in the cleaning tank. The cleaning device according to any one of claims 1 to 7.

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