Method for the optical examination of a liquid and washing machine with a lye container and a device for the optical examination of a washing solution containing particles

Description

[0001] The invention relates to a method for the optical examination of a washing liquor containing particles according to the preamble of patent claim 1.

[0002] US Pat. No. 4,406,028 A discloses a washing machine and a method with various sensors for detecting the color of a wash solution. US Pat. No. 2,007,46942 A1 discloses such a washing machine and a method with a multi-band color sensor.

[0003] Such a method can be used in a washing machine for the optical examination of the washing solution.

[0004] In such a method for the optical examination of a liquid containing particles, light emitted by a light source is coupled into the liquid. At least a portion of the coupled light is reflected by the particles in the liquid. The light reflected by the particles is then coupled out of the liquid. At least a portion of the coupled out, reflected light is then recorded by a receiver. Currently, only the intensity of the recorded light is evaluated, which then allows certain determinations about the turbidity of the liquid to be made.

[0005] The invention is based on the object of improving a method according to the preamble of claim 1 and a washing machine according to the preamble of claim 3 in such a way that the structure of the washing machine and its control are optimized.

[0006] This object is achieved by a method according to claim 1 and the washing machine according to claim 3 by the respective characterizing features. In the method according to the invention, the light received by the receiver is subjected to a spectral analysis. The spectral analysis can be carried out in particular with regard to the color components contained in the received light. This allows, in particular, the discoloration of the washing solution to be measured. Further embodiments of the invention are the subject of the dependent claims.

[0007] For comprehensive analysis, the light emitted by the light source may be visible white light.

[0008] According to the invention, the red, green, and blue light components of the light captured by the receiver are provided in the spectral analysis, allowing discoloration to be precisely detected. According to the invention, the turbidity of the wash liquor is determined from the spectral analysis of the light captured by the receiver.

[0009] For this purpose, the NTU (Nephelometric Turbidity Unit) characteristic curve is determined.

[0010] The invention further provides a washing machine with a device for optically examining a washing liquor containing particles, in particular a device operated by means of such a method, according to claim 3.

[0011] The device comprises a light source for emitting light into the wash liquor, a receiver for receiving light reflected by the particles in the wash liquor, and a microprocessor.

[0012] According to the invention, the receiver comprises a color sensor. The color sensor serves for the selective spectral detection of the light reflected by the particles in the wash liquor and measures a red light component, a green light component, and a blue light component and forwards it to the microprocessor. The light source, the receiver, and the microprocessor are arranged on a circuit board, which is provided on a translucent window and / or on an opening of the washing machine's tub. The microprocessor is designed to subject the light reflected by the particles, received by the receiver, to a spectral analysis with regard to the color components contained therein and to determine a red light component, a green light component, and a blue light component of the light received by the receiver and reflected by the particles as a discoloration of the wash liquor.Furthermore, the microprocessor is designed to determine an NTU (Nephelometric Turbidity Unit) characteristic curve as a turbidity of the washing liquor from the spectral analysis of the light received by the receiver and reflected by the particles, as well as to provide the color components and the turbidity to a control system of the washing machine as four output signals, which represent the red light component, the green light component and the blue light component as well as the NTU characteristic curve.

[0013] In a further embodiment of the device, the light source can be a lamp emitting white light, visible to the human eye. To save energy, a light-emitting diode can be used as the light source. For precise detection of discoloration, the color sensor measures the red, green, and blue light components of the light reflected by the particles in the wash solution. The measured red, green, and blue light components are simply transmitted to a microprocessor for further analysis.

[0014] In a compact design, the light source, the receiver with its color sensor and the microprocessor are arranged on a circuit board in the form of a sensor unit.

[0015] In a simple manner, the sensor unit can be provided for arrangement on a translucent window and / or on an opening of a container, in particular a suds container in a washing machine.

[0016] The washing machine, which is also referred to below as a cleaning appliance, can also comprise a control device for carrying out the treatment process. Furthermore, the cleaning appliance has a container for holding a cleaning liquid, wherein the cleaning liquid contains particles, for example, color and / or dirt particles arising during the treatment process. Finally, a device for optically examining the cleaning liquid is arranged on and / or in the container, for example at an opening of the container, at a translucent window of the container, or the like. This device can be designed in more detail as described above. With the help of this device, the discoloration of the cleaning liquid and / or the turbidity of the cleaning liquid can be detected.According to the invention, the device for optically examining the cleaning fluid provides the measured value for the red light component, the green light component, the blue light component and for the turbidity.

[0017] Furthermore, the measured value for the red light component, the green light component, the blue light component and the turbidity can be forwarded to the control unit so that the control unit can control the treatment process in an effective manner using this measured value.

[0018] The cleaning device is a washing machine, and the objects are laundry or similar.

[0019] The cleaning fluid can be water, possibly with detergent added. If discoloration is detected, the control unit can abort the treatment process to prevent damage to the items being treated. If excessive cloudiness is detected in the cleaning fluid, the control unit may initiate the addition of additional detergent and / or a further rinse with clean water to achieve an improved cleaning result.

[0020] A particularly preferred embodiment of the method according to the invention and the associated device is as follows: It provides for the color detection of washing liquor containing color particles and / or dirt particles in a washing machine. In addition, integrated turbidity detection is also performed.

[0021] The device suitable for this purpose comprises a reflection arrangement of optical components, whereby the beam coupled from a selectable light source is reflected by the particles in an aqueous solution and recorded by a color sensor. Due to the reflection from the particles, the wavelength of the light coupled into the medium changes depending on the color of the medium. An alternative selection of light sources for optimized matching of the receiver's light sensitivity allows for optimized signal behavior. This represents a significant difference from other color sensors for white goods, which couple via almost monochromatic light sources and only measure the reflected portion over a broadband range.

[0022] An integrated microprocessor processes the generated signals and passes them on to the washing machine's control system. A total of four output signals are provided: 1. the red light component, 2. the green light component, 3. the blue light component, and 4. the NTU (Nephelometric Turbidity Unit) characteristic curve.

[0023] This makes it possible the detection of the discoloration of washing liquor in the washing process of a washing machine and / or the determination of the control parameter for an optimized washing liquor dosage and / or the detection of possible contamination of freshly added water and / or the early detection of discoloring laundry items and / or the measurement of a turbidity characteristic curve in the critical lower turbidity range and / or the provision of easily interpretable measured values and their rapid integration into a washing machine process control system.

[0024] The advantages achieved by the invention are, in particular, that it makes it possible to prevent discoloration of garments during the washing process. Furthermore, an optimized use of detergents can be achieved using a detergent dosing system. Finally, improved detection of turbidity in washing solutions, particularly in addition to the detection of discoloration, and / or improved resolution in the measurement of turbidity are also possible.

[0025] An embodiment of the invention with various developments and refinements is shown in the drawings and is described in more detail below. Fig. 1 a device for optical examination of a washing solution in schematic view, Fig. 2 the arrangement of the device from Fig. 1 on the tub of a washing machine and Fig. 3 shows a device made of Fig. 2 cleaning device in schematic view.

[0026] In Fig. 1 1 schematically shows a device for the optical examination of a washing solution 1 containing particles 2, for example dye and / or dirt particles 2, wherein the washing solution 1 is also referred to below as liquid 1. Light 4 is emitted by a light source 3. This light 4 is coupled into the liquid 1. If the light 4 strikes a particle 2, a portion of this light 4 is reflected, while another portion of this light 4 can be absorbed by the particle 2. The light 5 reflected by the particles 2 is coupled out of the liquid 1. At least a portion of the coupled out, reflected light 5 is then received by a receiver 6. The light 5 received by the receiver 6 is then subjected to spectral analysis.With the aid of spectral analysis, the color components contained in the recorded reflected light 5 can be determined, so that the discoloration and / or contamination of the liquid 1 caused by the color and / or dirt particles 2 is measured.

[0027] The light source 3 can be a light-emitting diode (LED). Preferably, a light source that emits visible white light 4 is selected as the light source 3. The white light 4 is then composed of the corresponding components of red light 4a, green light 4b, and blue light 4c. Depending on the color of the particles 2, the reflected light 5 contains a corresponding red light component 5a and / or green light component 5b and / or blue light component 5c. The red light component 5a and / or the green light component 5b and / or the blue light component 5c are then provided in the spectral analysis of the light 5 received by the receiver 6. Expediently, the receiver 6 is then a color sensor, or the receiver 6 comprises a color sensor, wherein the color sensor measures the corresponding components 5a, 5b, 5c.The color sensor 6 thus serves in particular for the selective spectral detection of the light 5 reflected by the particles 2 in the liquid 1.

[0028] For further evaluation, the measured red light component 5a and / or green light component 5b and / or blue light component 5c or the corresponding signals of the receiver 6 are transmitted to a Fig. 2 The signal is transmitted to the microprocessor 7 shown. In the microprocessor 7, the turbidity of the liquid 1 can also be determined from the spectral analysis of the light 5 received by the receiver 6. The turbidity is provided as a so-called NTU (Nephelometric Turbidity Unit) characteristic curve.

[0029] The device for optically examining a liquid 1 containing particles 2 is described in more detail in Fig. 2 can be seen. The device comprises the illuminant 3 as a light source for emitting light 4 into the liquid 1 and the color sensor 6 as a receiver for receiving light 5 reflected by the particles 2 in the liquid 1, and optionally the microprocessor 7. The illuminant 3 and / or the color sensor 6 or the receiver 6 and / or the microprocessor 7 are arranged on a circuit board 8, 8' in the manner of a sensor unit 9. The sensor unit 9 has a housing 10 and a plug connection 11 for the electrical connection of the sensor unit 9. Furthermore, the housing 10 has a translucent window 12 which is assigned to the illuminant 3 and the color sensor 6.

[0030] As already mentioned, the sensor unit 9 can be used to detect the color of the washing solution 1 in the tub 13 of a washing machine. For this purpose, the sensor unit 9 is arranged in an opening 14 of the tub 13 such that the light 4, 5 can be coupled into the washing solution 1 through the window 12 and can be coupled out of the washing solution 1. The housing 10 of the sensor unit 9 is mounted in the opening 14 by means of a seal 15. Instead of an opening 14 in the tub 13, a window can also be provided in the tub 13, at which the sensor unit 9 is arranged, although this is not shown in more detail.

[0031] In Fig. 3 A schematic view of a cleaning device 16, which in this case is a washing machine, for treating laundry 17 is shown in more detail. The cleaning device 16 has a drum 18, which is rotatable by means of a motor, for holding the laundry 17. The drum 18 is arranged in a container 13 for holding a cleaning liquid 1, which is water mixed with detergent and / or clear water, so that the cleaning liquid 1 flows through the drum 18.

[0032] Furthermore, the cleaning device 16 has a control unit 19 for carrying out the treatment process for the laundry 17, wherein the control unit 19, among other things, controls the motor for rotating the drum 18 according to the washing program. Due to the treatment process, ie the washing process, the cleaning liquid 1 contains particles 2, as shown in Fig. 1. On and / or in the container 13, the Fig. 2 The sensor unit 9, shown in more detail, is arranged as a device for optically examining the cleaning fluid 1. With the aid of the sensor unit 9, the discoloration of the cleaning fluid 1 and / or the turbidity of the cleaning fluid 1 can be measured and / or detected.

[0033] As already shown by Fig. 1As described, the sensor unit 9 provides the measured value 20 for the red light component 5a and / or the green light component 5b and / or the blue light component 5c and / or for the turbidity. The measured value 20 for the red light component 5a and / or the green light component 5b and / or the blue light component 5c and / or for the turbidity is forwarded by the sensor unit 9 to the control unit 19 for use in controlling the treatment process. The measured value 20 is then evaluated in the control unit 19 with regard to the respective treatment process. Thus, if discoloration of the cleaning liquid 1 is detected, the treatment process can be aborted to prevent damage to the laundry 17. For this purpose, the control unit 19 sends an abort signal 21, which switches off the motor for rotating the drum 18.If excessive cloudiness of the cleaning fluid 1 is detected, for example, liquid detergent 22 located in a reservoir 23 can be added. For this purpose, the control unit 19 controls a dosing pump 25 using a pump signal 24, so that the dosing pump 25 pumps additional detergent 22 from the reservoir 23 via a supply line 26 into the container 13 in the desired amount.

[0034] The invention is not limited to the described and illustrated embodiment. Rather, it also encompasses all expert developments within the scope of the invention defined by the patent claims.

Claims

1. A method for the optical examination of suds (1) containing particles (2) in a washing machine with a sensor unit (9) comprising a light source (3) and a receiver (6), wherein light (4) emitted by the light source (3) is coupled into the suds (1), wherein light (5) reflected by the particles (2) is decoupled from the suds (1), and wherein at least a part of the decoupled, reflected light (5) is received by a receiver (6), characterized in that the light (5) received by the receiver (6) is subjected to a spectral analysis through a microprocessor with regard to the colour components contained therein and a red light component (5a), a green light component (5b) and a blue light component (5c) of the light (5) received by the receiver (6) is determined such that the colouring of the suds (1) is measured, and an NTU (Nephelometric Turbidity Unit) characteristics is determined as a turbidity of the suds (1) from the spectral analysis of the light (5) received by the receiver (6) through the microprocessor, wherein the colour components and the turbidity are provided to a controller of the washing machine as four output signals which reflect the red light component (5a), the green light component (5b) and the blue light component (5c) as well as the NTU characteristics.

2. The method for the optical examination of suds (1) containing particles (2) according to claim 1, characterized in that the light (4) emitted by the light source (3) is visible white light.

3. A washing machine with a suds container (13) and a device for the optical examination of suds (1) containing particles (2) with a sensor unit (9) comprising a light source (3), a receiver (6) and a microprocessor (7), wherein the light source (3) is provided for emitting light (4) into the suds (1), wherein the receiver (6) is provided for receiving light (5) reflected by the particles (2) in the suds (1), and wherein the receiver (6) comprises a colour sensor for the selective spectral detection of the light (5) reflected by the particles (2) in the suds (1), which to measure a red light component (5a) and a green light component (5b) and a blue light component (5c) of the light (5) reflected by the particles (2) in the suds (1) and to transmit to the microprocessor (7) for evaluation, wherein the light source (3), the receiver (6) with the colour sensor (6) and the microprocessor (7) are arranged on a printed circuit board (8, 8') which is provided at a translucent window and / or at an opening (14) of the suds container (13) of the washing machine, characterized in that the microprocessor is formed to subject the light (5) received by the receiver (6) and reflected by the particles (2) to a spectral analysis with regard to the colour components contained therein and to determine a red light component (5a), a green light component (5b) and a blue light component (5c) of the light (5) received by the receiver (6) and reflected by the particles (2) as a colouring of the suds (1), to determine an NTU (Nephelometric Turbidity Unit) characteristics as a turbidity of the suds (1) from the spectral analysis of the light (5) received by the receiver (6) and reflected by the particles (2), as well as to provide the colour components and the turbidity to a controller of the washing machine as four output signals which reflect the red light component (5a), the green light component (5b) and the blue light component (5c) as well as the NTU characteristics.

4. The washing machine according to the preceding claim, the sensor unit (9) has a housing (10) which is mounted on a window in the suds container (13) or in an opening (14) of the suds container (13) by means of a sealing (15).

5. The washing machine according to claim 3 or 4, characterized in that the light source (3) is an illuminant emitting visible white light.

6. The washing machine according to the preceding claim, wherein the illuminant is a light emitting diode.

7. The washing machine according to any one of claims 3 to 6, characterized in that the controller device (19) is formed to interrupt the treatment process when a colouring is determined and / or for subsequent dosing of detergent (22) if too much turbidity is detected.