The present invention relates to a household appliance comprising a UV light source.

One of the disinfection technologies in household appliances is the use of UV light sources. The use of UV light source can provide hygiene on its own, but in addition to the use of UV light source, effective hygiene performance can be achieved at lower temperatures and shorter programs for temperature values and program durations, which are supportive elements providing hygiene. The bacteria and virus elimination capacity of UV rays is directly proportional to the light intensity and the exposure time to light. Losses may occur in the light source power, which is one of the important parameters for hygiene performance, due to its lifetime or possible malfunctions/misuses. If these losses or malfunctions are not noticed, serious losses may occur in the hygiene performance provided by the technology and the developed algorithm. Due to this risk, there is a need for a detection system to monitor and control the amount of light emitted by the UV light source positioned in the household appliance.

In the state of the art Patent Application No. CN106245294, a household appliance is disclosed, comprising a UV light source.

In the state of the art European Patent Application No. EP3449947, a household appliance is disclosed, comprising a UV light source.

The aim of the present invention is the realization of a household appliance wherein the process to be adaptively applied to the material in the chamber according to the operational performance of the UV light source is controlled.

The household appliance of the present invention comprises a body; a chamber which is arranged in the body; a heater which heats the chamber; a UV light source which is disposed in the body and which emits UV light into the chamber; a housing wherein the UV light source is disposed; and a sensor which is disposed in the housing and which measures the light intensity.

The household appliance of the present invention further comprises a control unit which, when the data received from the sensor is below a first threshold value predetermined by the manufacturer, performs one of the embodiments which are to increase the operation time of the UV light source during the process to be applied to the materials in the chamber according to the program selected by the user, to increase the time of the process to be applied to the materials in the chamber according to the program selected by the user, and to increase the temperature in the chamber during the process. The parameters such as the process time, the operation time of the UV light source during the process, the temperature of the chamber during the process or the average temperature thereof, etc. are saved in the memory of the control unit for each program which can be selected via the control panel by the user. For example, when the household appliance is a laundry dryer, when a program is selected, the drying process time of 80 minutes in said program, the operation time of the UV light source of 15 minutes out of 80 minutes and the temperature in the chamber of 40° C during the drying process are saved in the memory of the control unit by the manufacturer. When the user selects said program via the control panel, the process is performed as saved in the memory of the control unit as long as the data received from the sensor is higher than the first threshold value. When the data received from the sensor falls below a first threshold value predetermined by the value as a result of the power of the UV light source and hence the light intensity thereof decreasing, the control unit increases the process time to be longer than 80 minutes, and/or increases the operation time of the UV light source to be longer than 15 minutes and/or operates the heater so as to increase the temperature in the chamber. The virus and bacteria elimination capacity of the UV light is directly proportional to the application time of the UV light and the intensity of the UV light. Therefore, when the intensity of the UV light emitted by the UV light source decreases, the operation time of the UV light source is increased so as to increase the application time of the UV light. Thus, losses which may occur in the disinfection performance are prevented. Moreover, it is known that most of the viruses and bacteria cannot survive at high temperatures (56° C or above). By increasing the ambient temperature as the efficiency of the UV light source decreases, the materials in the chamber are disinfected.

In an embodiment of the present invention, the household appliance comprises a visible light sensor which measures the amount of visible light. The UV light sources emit radiation at a plurality of wavelengths. Some of these radiations are at visible wavelengths and some are at UV light wavelengths. The power of the UV light source decreases as it is used, which causes a decrease in the intensity of the light emitted by the UV light source. There is a correlation between the decrease in the intensity of light at the visible wavelength and the decrease in the UV light intensity. After said correlation is defined in the control unit by the manufacturer, the decrease in the UV light intensity can be deduced from the decrease in the visible light intensity. Sensors which detect UV light are more expensive than sensors which detect visible light. By means of the sensor which detect visible light, the decrease in the intensity of the light emitted by the UV light source at the visible wavelength can be determined. According to the data received from the sensor and by means of the relation between the decrease in the visible light intensity and the decrease in the UV light intensity, the control unit can determine whether the UV light intensity is under the first threshold value.

In an embodiment of the present invention, the household appliance comprises the control unit which warns the user audibly and/or visually when the data received from the sensor falls below a second threshold value predetermined by the manufacturer. Thus, when the user is informed of the malfunction of the UV light source if the UV light source does not function properly.

In an embodiment of the present invention, the household appliance comprises a glass which almost completely covers the surface of the housing facing the chamber. The housing is covered by means of the glass. In a preferred embodiment of the present invention, the glass is manufactured from soda barium material.

In an embodiment of the present invention, the household appliance comprises a reflector which is provided in the housing and which reflects the rays emitted by the UV light source into the chamber. The reflector is manufactured from aluminum or Teflon material with high reflection performance. The reflector is disposed into the housing so as to be positioned behind the UV light source, and has a rounded form so as to surround the UV light source both from above and below. Thus, the UV rays to be emitted by the UV light source into the housing are transmitted into the chamber by being reflected from the reflector surface. In an embodiment of the present invention, the household appliance is a laundry dryer. In an embodiment of the present invention, the laundry dryer comprises a front bearing which rotatably supports the chamber and a housing which is arranged on the front bearing. The housing is positioned on the surface of the front bearing facing the interior of the chamber. Thus, the sensor in the housing is prevented from being affected by the light in the environment where the household appliance is installed, and from generating erroneous results.

In an embodiment of the present invention, the household appliance is a washing machine. The chamber is a washing chamber which is suitable for loading the laundry to be washed.

In an embodiment of the present invention, the household appliance is a cooking device. The chamber is a cooking chamber which is suitable for loading the foodstuffs to be cooked. In another embodiment of the present invention, the foodstuffs are placed into the chamber to be disinfected and exposed to UV rays.

In an embodiment of the present invention, the household appliance is a dishwasher. The chamber is a washing chamber which is suitable for loading the dishes to be washed.

By means of the present invention, a household appliance is realized, comprising the control unit which regulates the process to be applied to the material in the chamber according to the intensity of the light emitted by the UV light source such that the disinfection performance is increased.

The household appliance realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

Figure 1 - is the schematic view of the household appliance of the present invention.

Figure 2 - is the schematic view of the UV light source and the housing wherein the same is disposed of the present invention.

Figure 3 - is the perspective view of the front bearing whereon the housing is arranged.

The elements illustrated in the figures are numbered as follows:

1. Household appliance 2. Body

3. Chamber

4. Heater

5. Housing

6. UV light source

7. Sensor

8. Control unit

9. Glass

10. Reflector

11. Front bearing

The household appliance (1) comprises a body (2); a chamber (3) which is disposed in the body (2) and wherein the materials to be treated with one of the processes of drying, washing and cooking are loaded; a heater (4) which is provided in the body (2) and which heats the chamber (3); a housing (5) which is arranged in the body (2); and a UV light source (6) which is disposed in the housing (5) and which is suitable for emitting UV light into the chamber (3). The material to be treated can be a foodstuff to be cooked, laundry to be washed or dried or dishes to be washed. Depending on the type of the household appliance (1), the chamber (3) can be a washing chamber wherein the washing process is performed, a drying chamber wherein the drying process is performed and a cooking chamber wherein the cooking process is performed. The housing (5) is arranged on the body (2).

The household appliance (1) of the present invention comprises a sensor (7) which is disposed in the housing (5) and which detects the light intensity, and a control unit (8) which, when the data received from the sensor (7) is below a first threshold value predetermined by the manufacturer, increases the operation time of the UV light source (6) predetermined by the manufacturer according to the program selected by the user and/or increases the time of the process to be applied to the materials predetermined by the manufacturer according to the program selected by the user and/or operates the heater (4) so as to increase the temperature in the chamber (3) during the process. The virus and bacteria elimination effect of the UV light is directly proportional to the intensity of the light and the application time of the light. The UV light source (6) cannot always emit the UV rays at the same intensity. The sensor (7) is a sensor (7) which measures the intensity and/or amount of the light reaching the same. The sensor (7) is positioned on the side wall of the housing (5). By means of the sensor (7), the radiant power of the UV light source (6) and the intensity of the UV rays emitted by the UV light source (6) can be determined. The time of the process to be applied in the programs to be selected by the user via the control panel and the operation time of the UV light source (6) during the process are saved in the memory of the control unit (8) by the manufacturer. When the light intensity determined by the sensor (7) is below a first threshold value predetermined by the manufacturer, the operation time of the UV light source (6) during the process is increased according to the program selected by the user and/or the time of the process to be applied saved in the memory of the control unit (8) is prolonged and/or the temperature of the chamber (3) during the process is increased by a certain amount. In a preferred embodiment of the present invention, the first threshold value is defined as half of the intensity of the light emitted by the UV light source (6) working at full performance. For example, in a household appliance (1) having the drying function, the drying process lasts 50 minutes in a drying program and the UV light source (6) is operated for the last 15 minutes of said 50 minutes to provide disinfection. When said program is selected and the data received from the sensor (7) is below the first threshold value, the control unit (8) extends the operation time of the UV light source (6) during the drying process to 30 minutes. Moreover, the program time of 50 minutes is extended to 70 minutes such that the laundry loaded into the chamber (3) to be dried is treated for an extra time of 20 minutes so as to be disinfected. In addition, the temperature of the chamber (3) wherein the drying process is performed is increased by the control unit (8) operating the heater (4) such that the bacteria and viruses are eliminated by high heat. Thus, even if the efficiency of the UV light source (6) decreases, the disinfection performance is improved.

The household appliance (1) of the present invention comprises the sensor (7) which is a visible light sensor detecting the amount of visible light. Lights at wavelengths between 380 nm and 700 nm can be seen with the human eye and are called visible light. The UV light source (6) not only emits UV light that the human eye cannot see, but also emits different lights at a wavelength between 380nm and 700nm. The UV light source (6) loses the radiant power thereof over time. While the UV light at a wavelength of 254 nm is emitted at an intensity of 0.113 from a fully functioning UV light source (6), the light at the visible wavelength of 577 nm is emitted at an intensity of 0.185 units. When the UV light source (6) is measured after a certain amount of use, it is determined that a UV light at a wavelength of 254 nm is emitted at an intensity of 0.049 units, and the visible light at a wavelength of 577 nm is emitted at an intensity of 0.075 units. Since the light intensities of both lights decrease at similar rates throughout the usage period, the sensor (7) to be placed in the housing (5) can be a visible light sensor which detects visible light. Sensors which detect visible light are much cheaper than sensors which detect UV light. Thus, the present invention can be applied in a cost-effective manner.

In an embodiment of the present invention, the household appliance (1) comprises the control unit (8) which warns the user audibly and/or visually that the UV light source (6) does not run properly when the data received from the sensor (7) reaches a second threshold value predetermined by the manufacturer and falls below the second threshold value. The second threshold value is zero or a value close to zero, and is used to detect situations where the UV light source (6) emits almost no light. When the data received from the sensor (/) reaches the second threshold value or falls below such value, the user is warned audibly and/or visually. Thus, the user can understand that the UV light source (6) does not run properly, and can replace the UV light source (6).

In an embodiment of the present invention, the household appliance (1) comprises a glass (9) which completely covers the surface of the housing (5) facing the chamber (3) and which is manufactured from a material which allows UV light transmittance. Thus, the UV light source (6) is protected against external mechanical factors. In a version of the present invention, the glass (9) is manufactured from quartz material which allows the passage of UV rays.

In an embodiment of the present invention, the household appliance (1) comprises a reflector (10) which is provided in the housing (5) so as to be positioned behind the UV light source (6) and which reflects all the rays emitted by the UV light source (6) into the chamber (3). By means of the reflector (10), the UV rays emitted by the UV light source (6) towards the interior of the housing (5) are directed into the chamber (3). Thus, the amount of UV rays to be sent onto the laundry is increased and the laundry is sterilized.

In an embodiment of the present invention, the household appliance (1) is a laundry dryer. In this case, the material to be treated is laundry while the chamber (3) is the drying chamber, in other words the drum wherein the drying process is performed. The user selects the drying process program to be applied to the laundry via the control panel. If the intensity of the light emitted by the UV light source (6) is higher than the first threshold value during the drying process, the drying process is performed as the selected program saved in the memory of the control unit (8). If the value received by the sensor (7) is below the first threshold value during the drying process, the control unit extends the operation time of the UV light source (6) during the selected program in order to prevent any decrease in the disinfection performance. Thus, the operation time of the UV light source (6) is adaptively adjusted, and the disinfection performance of the laundry dryer is increased. Moreover, when the data received from the sensor (7) is equal to or below the first threshold value during the drying process, the drying process time to be applied in the program selected by the user via the control panel can be longer than the value saved in the memory of the control unit (8) for said program. In other words, the decrease in the disinfection performance which may be caused by the decrease in the power of the UV light source (6) is compensated by increasing the process time. Moreover, the data received from the sensor (7) during the drying process is equal to or below the first threshold value, the control unit (8) operates the heater (4) to increase the temperature of the chamber (3). Since most of the bacteria and viruses cannot survive at temperatures higher than 56° C, when the power of the UV light source (6) decreases, the ambient temperature is increased so as to disinfect the laundry.

In an embodiment of the present invention, the household appliance (1) comprises a front bearing (11) which rotatably supports the chamber (3) and the housing (5) which is arranged on the front bearing (11). The housing (5) is positioned on the surface of the front bearing (11) facing the interior of the chamber (3). Thus, the sensor (7) in the housing (5) is prevented from being exposed to light coming from outside the body (2), and is enabled to receive light only from the UV light source (6). Consequently, the intensity of the light emitted by the UV light source (6) can be measured more correctly. In an embodiment of the present invention, the household appliance (1) is a washing machine. In a preferred version of the present invention, the UV light source (6) is disposed in the bellows provided in the body (2) of the washing machine.

In an embodiment of the present invention, the household appliance (1) is a cooking device. In an embodiment of the present invention, the household appliance (1) is a dishwasher. In a preferred version of the present invention, the UV light source (6) is disposed on the door which allows access or prevents access into the chamber (3).

By means of the present invention, a household appliance (1) with improved disinfection performance is realized, comprising the control unit which adjust the operation time of the UV light source (6) and/or the process time and/or the temperature of the chamber (3) according to the intensity of the light emitted by the UV light source (6).