CN107794722B

CN107794722B - Transparency-adjustable laundry treatment appliance with a door insert and corresponding operating method

Info

Publication number: CN107794722B
Application number: CN201710784249.XA
Authority: CN
Inventors: M·克莱因
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2016-09-06
Filing date: 2017-09-04
Publication date: 2022-03-01
Anticipated expiration: 2037-09-04
Also published as: CN107794722A; EP3290576A1; DE102016216897A1; EP3290576B1

Abstract

The invention relates to a laundry treatment appliance 1 having a housing 2, a treatment chamber 3 for laundry to be treated, a control unit 4, and a door unit 5 for opening and closing the treatment chamber 3, wherein the door unit 5 has a door insert 6 for closing the treatment chamber 3, which door insert comprises a transparent material 7, characterized in that the door insert 6 has a first layer 8, the light transmittance of which can be changed by changing the temperature and/or electrical properties of the first layer 8, wherein the door insert 6 is configured such that it is in a transparent state when an operating program is not being carried out. The invention also relates to a method for operating the laundry treatment appliance.

Description

Transparency-adjustable laundry treatment appliance with a door insert and corresponding operating method

Technical Field

The invention relates to a laundry treatment appliance having a housing, a treatment chamber for laundry to be treated, a control unit, a door unit for opening and closing the treatment chamber, wherein the door unit has a door insert which closes the treatment chamber, the door insert comprising a transparent material. The invention also relates to a method for operating the laundry treatment appliance.

Background

Laundry treatment appliances such as washing machines and dryers usually have a drum as a treatment chamber for the laundry, which treatment chamber is accessible via a door unit. The door unit, i.e. the window leading to the drum, is usually composed of a plastic frame and a transparent glass connected thereto. The frame and the glass can be connected by bolting, gluing, welding or by injection molding. This connection allows the use of different glasses and also the electrical manipulation of the door unit and the glass used therein.

The use of external touch-sensitive operating devices for operating household appliances, such as washing machines, dryers or stoves, has become increasingly popular in the last years. Such a touch-sensitive operating device may be, for example, a smartphone or also a tablet power supply. They usually have a touch screen which combines a display device with an operating device. The operation of the household appliance mostly takes place by the App. Although a fast operation of the household appliance can be achieved in this way, the touch screens available on smartphones and tablet computers are mostly very small. The technology available in domestic appliances has however become more and more sophisticated in the last years, and the operation has therefore become more and more complex. Therefore, displaying summaries of complex content on small touch screens poses a challenge. It is therefore desirable to additionally provide the following possibilities in the context of domestic appliances: complex content is displayed over a large area.

Publication WO 2010/128729 a2 describes a washing machine comprising a casing forming the external appearance of the washing machine and containing an opening. The drum is rotatably supported inside the housing and loaded with laundry through the opening. The housing further has a door for opening and closing the opening, wherein a display unit for showing washing information is provided on the door.

Publication WO 2006/021936 a1 describes a domestic appliance comprising a housing, a door mounted on the housing and enabling a user to access the interior of the housing, and a window positioned on the housing and/or the door and allowing the user to view the interior of the housing. A display unit is mounted on the window, the display unit allowing a user to observe data provided by the control card for controlling the home appliance while observing the inside of the housing through the window.

Publication GB 2511360 describes a laundry treatment machine, in particular a washing machine and a drying machine. There are drums for laundry having windows or glass parts that allow line of sight into the drum. At least a portion of which has thermochromic properties. Here, the glass may have such thermochromic properties or a sticker or film having thermochromic properties may be bonded to the glass. The door may for example be at least partly made of a material, such as synthetic plastic, in which pigments having thermochromic properties are contained.

The patent of us patent No. 5,451,932 describes a method and device for explaining the state of a household appliance. The apparatus for displaying a change between first and second operating conditions of a household appliance further comprises an elongated thermally conductive substrate in heat transfer relationship with the first heater and disposed adjacent the first heating appliance so as to derive thermal energy generated by the first heating appliance and conduct the heat; and a temperature sensitive material included on the substrate, the material being capable of changing its appearance as a reaction to a change in temperature of the conductive substrate. The temperature-sensitive material comprises in particular a thermochromic material. In an embodiment, beneath the layer of thermochromic material is a dyed material, wherein the thermochromic material may be opaque when cooled below a threshold temperature so as to obstruct the view of the dyed material, and may become transparent when heated above the threshold temperature so as to enable the dyed material to be viewed.

The publication KR 20140125996 a describes a refrigerator that can change its external appearance to be transparent or opaque by using an electrochromic device. An electrochromic device comprising: a transparent first electrode disposed within the transparent first substrate; an electrochromic first layer positioned in the first electrode; a transparent second electrode positioned within a transparent second substrate, the second substrate opposing the first substrate; and an electrolyte layer between the electrochromic first and second layers. Energy losses can thus be prevented in this way, since the door does not have to be opened in order to observe the interior.

Disclosure of Invention

Against this background, the object of the present invention is to provide a laundry treatment appliance having an improved display device. In particular, it should be possible to increase the safety during the operation and running of the household appliance and to make the display of information on the display device more user-friendly. The possibility of using different design elements during operation of the laundry treatment appliance should preferably also be achieved. Furthermore, it is an object of the present invention to provide a method for operating such a laundry treatment appliance.

According to the invention, this object is achieved by the laundry treatment appliance according to the invention and by a method suitable therefor. The invention also relates to preferred embodiments of the laundry treatment appliance according to the invention and of the method according to the invention. Even if this is not specified in detail here, preferred embodiments of the laundry treatment appliance according to the invention correspond to preferred embodiments of the method according to the invention and vice versa.

The subject matter of the invention is therefore a laundry treatment appliance having a housing, a treatment chamber (typically a drum) for the laundry to be treated, a control unit, and a door unit for opening and closing the treatment chamber, wherein the door unit has a door insert for closing the treatment chamber, which door insert comprises a transparent material, wherein the door insert has a first layer, the light transmittance of which can be changed by a change in the temperature and/or electrical properties of the first layer, wherein the door insert is configured such that it is in a transparent state when no operating program is carried out.

The transparent material is in particular plastic or glass, preferably glass. The door unit usually also comprises, in addition to the door insert, a frame surrounding the door insert.

According to the invention, the term "first layer" is to be interpreted broadly and also includes, in particular, inhomogeneous layer structures in which different low-molecular or high-molecular substances having thermochromic and/or electrochromic properties can be embedded. The first layer can be arranged in the door insert in different ways. The first layer may be arranged as an outer layer on the transparent material, such that the first layer is arranged as an inner or outer layer with respect to the arrangement with respect to the process chamber. However, the first layer is preferably between two plates made of transparent material. In this way, the first layer is protected, for example, from external or internal damage due to external impacts or other external factors or processes running in the process chamber.

According to the invention, laundry treatment appliances in which the first layer has electrochromic properties are preferred. Here, the concept "electrochromic properties" means that a change in applied current or applied voltage causes a change in light transmission and/or color.

The electrochromic properties can be adjusted in different ways. Preferably, the laundry treatment appliance has a control unit for controlling the electrochromic properties in accordance with a treatment program implemented in the laundry treatment appliance and/or in accordance with an input on the operating unit.

For example, the electrochromic of the first layer can be controlled in such a way that symbols or characters are displayed which indicate an operating program (for example a washing program or a drying program). However, it is likewise possible to show different program phases by means of different colors of the door insert. Finally, the program phase change or interruption can be indicated by a flashing of the door insert, wherein "flashing" means that the transparency or the color of the door insert changes within a short time interval.

As electrochromic substances (also referred to herein as "electrochromic active substances") inorganic or organic substances can be used. Suitable electrochromic substances are, for example, tungsten oxide. When a charge is exported onto a thin coating of tungsten oxide, the coating is made optically active and changes its color. When tungsten oxide is used as electrochromic substance, there is, for example, a conductive, transparent polymer film in the first layer, which polymer film separates the electrode comprising tungsten oxide from the counter electrode comprising lithium ions.

However, it is preferable to use an organic substance as the electrochromic substance. The first organic substance-based electrochromic layer generally comprises an active electrochromic layer, in particular between electrodes arranged perpendicularly with respect to one another. In this case, the electrodes are located, for example, on the surfaces of the two glass plates adjacent to the first layer. For this purpose, the two glass plates are usually coated in an electrically conductive manner and provided with electrical connections.

The main constituents of the active layer inside the first layer can be, for example, redox systems and pH-active pigments. Here, the concentration ratio of the redox couple is changed by applying a voltage so that protons and/or other ions are released or bound. This acts on the pH, causing the pH-active pigment to undergo a color change.

Particularly suitable electrochromic substances are organic polymers in which the different oxidation states are distinguished by their color. Here, however, the cations and/or anions are also moved, in particular for charge balancing after the redox process. Suitable organic polymers are, in particular, electrically conductive organic polymers such as viologens, polythiophenes and polyanilines.

The operation of the laundry treatment appliance can be carried out in different ways. The operating unit can therefore be fixedly mounted on the laundry treatment appliance. Alternatively or additionally, a mobile operating unit can be provided. The mobile operating unit is preferably configured as an external touch screen.

In a preferred embodiment, the laundry treatment appliance has at least one operating unit in the form of an external touch screen and an interface for communication between the control unit and the operating unit. The operating unit in the form of an external touch screen is in particular a smartphone or a tablet computer. The operating unit is generally provided for controlling the laundry treatment appliance. If the operating unit is a mobile external operating unit, i.e. an operating unit which is not fixedly positioned on the laundry treatment appliance, for example an external operating unit in the form of an external touch screen, the connection between the control unit and the operating unit is usually a wireless connection for data exchange. Such a connection may be established, for example, via WLAN, bluetooth, etc. According to the present invention, the type of wireless connection is not limited. Data are exchanged between the control unit and the external operating unit at least by means of the connection.

The generally used, external and/or internal operating unit is preferably provided for forming a screen display for controlling the laundry treatment appliance on the first and/or second floor. Here, the concept "screen display" is to be broadly understood. For example, a colored, for example red screen display can be provided, which extends over the entire door insert. When a red screen display is realized by way of the first layer being provided with electrochromic properties, different optical effects can be envisaged, for example flashing of the entire surface of the door insert or other optical movement processes.

Preferably, according to the invention, in particular when the first and/or second layer contains an electrochromic substance, the first and/or second layer preferably shows text, symbols, patterns and/or pictures, wherein a picture also means a picture in monochrome, which picture extends over the entire door insert. Which may be still pictures or animations. Here, the text includes letters, numbers, and special symbols. The representation can be performed in color, grayscale and/or black/white. The design of the content is targeted for the respective user groups in the following ways: the user group for example prefers traditional, functional or modern presentation.

Laundry treatment appliances in the sense of the present invention are usually washing machines, dryers or washer-dryers. In order to receive and treat the objects, the laundry treatment appliance comprises a treatment chamber. The treatment chamber is in particular a drum if the laundry treatment appliance is a washing machine, a drying machine or a washer-dryer.

In order to be able to receive the items of laundry to be treated, the treatment chamber has an opening through which the items of laundry can be loaded. The treatment of the laundry is usually carried out under defined process conditions, i.e. dry hot process air in a clothes dryer or wash liquor in a washing machine. It is therefore generally necessary that the treatment chamber can be closed during the treatment of the laundry. The laundry treatment appliance according to the invention therefore has a door unit for opening and closing the treatment chamber. The configuration of such a door unit is not restricted, but generally depends on the type of laundry treatment appliance and therefore on the type of treatment taking place in the treatment chamber.

The door unit provided according to the invention preferably has at least one door frame, a hinge and at least one transparent first door insert, the hinge being mounted such that it enables the opening and closing of the door unit on the laundry treatment appliance.

The transparent material only has to be adapted to the respective process conditions during the treatment of the objects in the treatment chamber, depending on the type and configuration of the laundry treatment appliance. Typically, the transparent door insert is made of glass or a plurality of glasses. However, the tolerance of the transparent door insert with respect to the individual process conditions present in the treatment chamber can also be provided by a defined thickness of the door insert.

The shape of the door insert, in particular of the transparent door insert, can also be different depending on the type of laundry treatment appliance and the configuration of the treatment chamber. The transparent door insert in the door unit of a washing machine usually has the shape of a round window. The material, thickness and shape of the door insert depend at least on the type and configuration of the laundry treating appliance in which the door insert is used.

Based on the presence of the first layer and, if appropriate, the second layer, the door insert can be opaque, transparent (i.e. transparent) or partially transparent, depending on the extent to which the user of the laundry treatment appliance should be able to see into the interior of the treatment chamber.

Finally, according to the invention, preference is given to laundry treatment appliances in which the first layer and/or the second layer have thermochromic properties.

In a preferred embodiment, the first layer has thermochromic properties. I.e. the first layer changes colour upon a change in temperature. This process is generally reversible. The thermochromic behavior is here given by the presence of the thermochromic substance. Thermochromic substances are, for example, inorganic compounds such as rutile and zinc oxide, or organic compounds such as Bixantylidenverbundingen and Bianthronylverbundingen (German). For example, 9 '-Bixantyliden and 10,10' -Biantrhronylden are used for this purpose. Polymers, for example polyether components containing lithium chloride, are also suitable in particular as organic compounds.

According to the invention, it is preferred that the laundry treatment appliance has a thermochromic chemical substance arranged in the first and/or second layer and an electrochromic substance arranged in the first layer in such a way that the substances are located in different regions of the door insert, as viewed in the direction of the door insert. This makes it possible to insert thermochromic and electrochromic substances separately for the purpose of displaying information and/or designs on the door insert. This is particularly advantageous when the information about the temperature present in the process chamber is to be displayed as separate information on the door insert. This can be achieved, for example, by a thermochromic substance being present only in certain regions of the door insert.

In a particularly preferred embodiment of the laundry treatment appliance according to the invention, the second layer has thermochromic properties and is located closer to the treatment chamber than the first layer. In this embodiment, the distance between the process chamber (whose temperature is to be tracked if necessary) and the thermochromic substance is particularly small.

Finally, it is particularly preferred according to the invention that in the laundry treatment appliance the first layer and/or the second layer is arranged between the two glass panes of the door insert.

The first layer and, if appropriate, the second layer or further layers having electrochromic and/or thermochromic properties are usually not uniformly formed, but in turn form a layer structure, in particular a non-uniform layer structure. The layer structure depends in particular on whether and which thermochromic and/or electrochromic substances are introduced. When using electrochromic substances, it is a consideration that electrodes must generally be applied to the first layer for the purpose of controlling them. This means that, in the case of an electrochromic first layer, this is usually arranged between two transparent plates, on which electrodes are applied.

According to the invention, laundry treatment appliances in which the first layer is electrochromic and is configured as a display device for displaying information about the laundry treatment appliance and/or a treatment program running therein are preferred.

In particular, it is advantageous when electrochromic compounds are used if the laundry treatment appliance comprises at least one sensor for measuring an operating parameter and the control unit is provided for displaying the measured operating parameter in a first layer configured as a display device. The sensor may be, in particular, a temperature sensor, but may also be, for example, a pressure sensor or a load sensor.

In a preferred embodiment, the laundry treatment appliance comprises a motion sensor which can determine whether a user is present in the vicinity of the laundry treatment appliance, and the control unit is provided for causing a control of the first layer predetermined for this case if presence has been determined. Here, "vicinity" may be a fixedly set or user-adjustable quantity depending on the standing position, wherein the distance and/or height of the moving object (user) may be taken into account if necessary. Such a motion sensor also enables recognition of gestures, if necessary. This embodiment makes it possible at least for the display on the door insert, i.e. the control of the electrochromic first layer, to be adapted to the user. When reference is made herein to an "electrochromic layer" or a "thermochromic layer", this means in particular that the layer has electrochromic or thermochromic properties. This does not mean that the layer may not also have the corresponding other properties, i.e. thermochromic or electrochromic properties.

In a further preferred embodiment, the laundry treatment appliance comprises a light sensor which can detect the light intensity L in the surroundings of the laundry treatment appliance_UAnd the control unit is arranged to be below the minimum value L_UminWhile increasing the transparency of the first layer and/or exceeding the maximum value L_UmaxThe transparency of the first layer is reduced.

The laundry treatment appliance according to the invention is generally configured such that the transparency of the door insert is reduced after the laundry treatment appliance has been opened, preferably at the beginning of a treatment program, either only such transparency is reduced or the transparency is reduced by changing color. This does not exclude: the transparency increases and decreases again during the processing procedure. This is particularly the case when the door insert is color changing. Furthermore, the transparency or the color of the door insert can be changed, if necessary repeatedly, depending on the region of the door insert that is to be viewed.

However, it is also possible according to the invention for the door insert to be at least partially permanently transparent, so that it enables a user to view the treatment chamber. This means in particular that the user can observe the treatment chamber and the items of laundry located therein in this embodiment independently of the switched-on state of the laundry treatment appliance or of the proceeding of the treatment program.

Furthermore, the subject matter of the invention is a method for operating a laundry treatment appliance having a housing, a treatment chamber for laundry to be treated, a control unit, a door unit for opening and closing the treatment chamber, wherein the door unit has a door insert for closing the treatment chamber, which door insert comprises a transparent material, wherein the door insert has a first layer, the light transmittance of which can be changed by changing the temperature and electrical properties of the first layer, wherein the door insert is configured such that it is in a transparent state when no operating program is carried out, comprising the following steps:

(a) opening the laundry treatment appliance and establishing an electrical connection between the control unit and the electrochromic-active substance in the first layer;

(b) applying a voltage or a current to the first layer in order to cause the transparency of the first layer to be reduced as desired under the control of the control unit in response to an input on the operating unit and/or in response to the display of information about the laundry treatment appliance and/or a treatment program running in the laundry treatment appliance; and

(c) the transparent state is reestablished at the latest after the laundry treatment appliance has been switched off.

In this case, the opening of the laundry treatment appliance and the establishment of an electrical connection between the control unit and the electrochromic active substance in the first layer can take place simultaneously or successively.

The transparent state can be reestablished at the end of the treatment program or, if necessary, at an earlier predetermined point in time, but at the latest when or after the laundry treatment appliance is switched off. In this case, it may also be provided that the gate unit flashes at the end of the processing program.

The concept "handler" is generally to be broadly construed herein. The treatment program may comprise a program which can be standardized in the laundry treatment appliance, the parameters of which program are stored in advance as default values in the control device, i.e. a so-called standard treatment program; and including a handler with additional options, i.e. with program parameters that can be changed by the user with respect to the standard setting. Additional options can be predefined items, such as a delayed start, a program sequence designed to meet other predefined items, such as rapidity, a washing program which is run in the washing machine, for example, as quickly as possible, or a washing program designed for energy efficiency, a cleaning step, or a washing program which is adapted to a specific soil (such as blueberry soil or red wine soil), for example.

The present invention has many advantages. For example, a display device applied to the door insert by means of an electrochromic substance can be designed over a large area and, in an embodiment of the invention, at the same time allows a user to observe the interior of the process chamber. The possibility of an enlarged display of specific operating states, for example, operating disturbances, increases the operating safety of the household appliance in particular. In an embodiment of the invention, the user can immediately know even at a distance if there is a malfunction on the appliance and take corresponding measures. Even in a dark room, in the absence of light, or during nighttime descent, the following advantages are provided: a display of content that is magnified and well readable. Furthermore, the invention enables additional design possibilities and thus personalized features for the user of the laundry treatment appliance.

Drawings

Further details of the invention are given by the following description of an embodiment for a laundry treatment appliance according to the invention, which is not limiting of the invention. Reference is made herein to fig. 1 and 2.

Fig. 1 shows a side view of a laundry treatment appliance according to the invention.

Fig. 2 shows a perspective view of a laundry treatment appliance according to the invention.

Detailed Description

In fig. 1, the laundry treatment device 1 is a washing machine in an embodiment not limiting the present invention. The washing machine has a housing 2, on which a door unit 5 is mounted for opening and closing a drum 3, which serves as a treatment chamber for laundry, not shown here. The door unit 5 comprises a door insert 6 which is transparent in the off state of the laundry treatment appliance. In the embodiment shown here, the door insert 6 comprises two

glass plates

12 and 13 as transparent material 7, between which a first layer 8 and a second layer 11, each having electrochromic and thermochromic properties, are located. The thermochromic and electrochromic substances are arranged in the first layer 8 and the second layer 11 in such a way that they are located in different regions of the door insert 6 when viewed in the direction of the door insert 6. This makes it possible, for example, to arrange in particular a thermochromic substance in the first and/or

second layer

8, 11 in the lower part of the door insert 6, which can directly reflect the temperature within the treatment chamber 3, and in particular an electrochromic substance in the first and/or

second layer

8, 11 in the upper part of the door insert 6, so that information about the laundry treatment appliance 1 and the treatment program taking place therein can be shown in the upper part in a controlled manner by the control unit 4.

In the laundry treatment appliance shown in fig. 1, the operating unit 9 is mounted statically.

Fig. 2 shows a perspective view of a laundry treatment appliance 1 according to the invention, here configured as a drying machine, wherein a smartphone 10 is used as an external operating unit as operating unit 9. Here, 14 denotes an electronic control device for an electrochromic first layer, i.e. with an electrochromic substance, which is not shown in any more detail here.

In the laundry treatment appliance of fig. 1 and 2, the method according to the invention can be carried out.

List of reference numerals

1 washing treatment device

2 casing

3 treatment chamber

4 control unit

5-door unit

6 door insert

7 transparent material, here a glass plate

8 first layer (having electrochromic and/or thermochromic properties)

9 operating unit

10 external operation unit

11 second layer (having electrochromic and/or thermochromic properties)

12 first glass plate

13 second glass plate

14 electronic control device for an electrochromic first layer

Claims

1. Laundry treatment appliance (1) having a housing (2), a treatment chamber (3) for laundry to be treated, a control unit (4), a door unit (5) for opening and closing the treatment chamber (3), wherein the door unit (5) has a door insert (6) for closing the treatment chamber (3), which door insert comprises a transparent material (7), characterized in that the door insert (6) has a first layer (8), the light transmittance of which can be changed by a change in the temperature and/or electrical properties of the first layer (8), wherein the door insert (6) is configured such that it is in a transparent state when an operating program is not carried out,

wherein the first layer (8) is electrochromic and is configured as a display device for displaying information about the laundry treatment appliance (1) and/or about a treatment program running in the laundry treatment appliance,

wherein the laundry treatment appliance (1) comprises a light sensor which is able to detect a light intensity L in the surroundings of the laundry treatment appliance (1)_UAnd the control unit (4) is arranged to be below a minimum value L_UminThe transparency of the first layer (8) is increased and/or the maximum value L is exceeded_UmaxWhile reducing the transparency of said first layer (8),

wherein the laundry treatment appliance comprises a sensor for measuring an operating parameter, and the control unit (4) is provided for displaying the measured operating parameter in a first layer (8) configured as a display device.

2. Laundry treatment appliance (1) according to claim 1, characterized in that the control unit (4) is provided for controlling the electrochromic properties in accordance with a treatment program implemented in the laundry treatment appliance (1) and/or in accordance with an input on an operating unit (9, 10).

3. Laundry treatment appliance (1) according to claim 2, characterized in that it has an operating unit (9) configured as an external touch screen (10) and has an interface for communication between the control unit (4) and the operating unit (9).

4. Laundry treatment appliance (1) according to any of the claims 1 to 3, characterized in that the door insert (6) further has a second layer (11), the second layer (11) being closer to the treatment chamber (3) than the first layer (8), the first layer (8) and/or the second layer (11) having thermochromic properties.

5. Laundry treatment appliance (1) according to claim 4, characterized in that the first layer (8) has thermochromic properties.

6. Laundry treatment appliance (1) according to claim 4, characterized in that in the first layer (8) and/or in the second layer (11) thermochromic chemicals and in the first layer (8) electrochromic substances are arranged such that they are in different regions of the door insert (6) when viewed in the direction of the door insert (6).

7. Laundry treatment appliance (1) according to claim 4, characterized in that the second layer (11) has thermochromic properties.

8. Laundry treatment appliance (1) according to claim 4, characterized in that the first layer (8) and/or the second layer (11) are arranged between two glass plates (12, 13) of the door insert (6).

9. Laundry treatment appliance (1) according to any of claims 1 to 3, characterized in that the laundry treatment appliance (1) comprises a motion sensor which is able to determine whether a user is present in the vicinity of the laundry treatment appliance (1), and in that the control unit (4) is provided for causing a control of the first layer (8) which is predefined for the situation if this presence has been determined.

10. Laundry treatment appliance (1) according to any of claims 1 to 3, characterized in that the door insert (6) is at least partially permanently transparently configured, such that it enables a user to view the treatment chamber (3).

11. Method for operating a laundry treatment appliance (1) having a housing (2), a treatment chamber (3) for laundry to be treated, a control unit (4), and a door unit (5) for opening and closing the treatment chamber (3), wherein the door unit (5) has a door insert (6) for closing the treatment chamber (3), which door insert comprises a transparent material (7), wherein the door insert (6) has a first layer (8), the light transmittance of which can be changed by a change in the temperature and/or electrical properties of the first layer (8), wherein the door insert (6) is configured such that it is in a transparent state when an operating program is not carried out, wherein the first layer (8) is electrochromic and is configured as a display device, for displaying information about the laundry treatment appliance (1) and/or about a treatment program running in the laundry treatment appliance, wherein the laundry treatment appliance (1) comprises a light sensor which is able to detect a light intensity L in the surroundings of the laundry treatment appliance (1)_UAnd the control unit (4) is arranged to be below a minimum value L_UminThe transparency of the first layer (8) is increased and/or the maximum value L is exceeded_UmaxWhile reducing the transparency of said first layer (8), said method comprising the steps of:

(a) opening the laundry treatment appliance (1) and establishing an electrical connection between the control unit (4) and the electrochromic active substance in the first layer (8);

(b) -applying a voltage or a current to the first layer (8) in order to cause a desired reduction in the transparency of the first layer (8) in response to an input on an operating unit (9, 10) and/or in response to the display of information about the laundry treatment appliance (1) and/or about a treatment program running in the laundry treatment appliance, controlled by the control unit (4); and is

(c) The transparent state is reestablished at the latest after the laundry treatment appliance (1) has been switched off,