FIELD OF THE INVENTION

The invention relates to a garment steamer having a steam generator and control means for controlling steam output from the steam generator. The invention may be used in the field of garment care.

BACKGROUND OF THE INVENTION

Garment steamers typically comprise a steam generator for generating steam, and a steamer head having steam vents from which the generated steam passes out of the steamer head and towards a garment being treated. Garment steamers tend to be used for steaming garments, fabric-like materials hung over a steaming board or laid over a hard surface, or for steaming hanging upholstery, drapes, etc. Such steam treating may be for the purpose of removing wrinkles, refreshing or straightening fabric, etc. Such garment steamers may include a trigger in the form of one or more elastically loaded push buttons to control the steam release or steam generation process according to when the steam is required for treating the garment. In this way, the push button(s) may provide a trigger control for the user to release steam from the steamer head as-needed. The push button(s) is/are usually integrated into the handle of the garment steamer, which is a convenient location for the user. The push button(s) may, however vary in size, shape and placement across various steamer models.

In one example, pushing of the push button causes a signal to be sent directly to a controller that controls a water pump. In response to the push button signal, the controller controls the water pump to pump a suitable amount of water from a water tank to the steam generator in order to generate steam. Depending upon the model, the steam generator is enclosed in a base of a stand garment steamer or is mounted in the steamer head itself. In another example, the garment steamer has a steam generator and an electronic valve for controlling the release of steam from the steam generator. In such a design, the push button controls the electronic valve via a controller.

Whilst the trigger control provided by the push button(s) has advantages, such as energy and water efficiency benefits, there are certain disadvantages. For example, the user may experience physical fatigue due to the requirement to maintain pressure on the push button in order for steam delivery to be maintained. The requirement to push the button also adds a further step which the user must perform in order to steam treat a garment or fabric.

Some garment steamers may not provide such a trigger control, such that the steam output is continuous while the device is switched on. In these designs, water pools in the steam generator which results in continuous generation of steam. Users of such garment steamers may accordingly not experience the above-described disadvantages of the push button, but control over the steam release/generation process itself is nonetheless limited. Such devices may also have inherent problems associated with higher water and energy consumption.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the invention to propose garment steamer that avoids or mitigates the above- mentioned problems.

The invention is defined by the independent claims. The dependent claims define advantageous embodiments.

To this end, the garment steamer according to the invention comprises: a steam generator for generating steam, a steamer head comprising a laser sensor for measuring the distance between the steamer head and a garment placed in front the laser sensor, control means to control, based on the distance, the delivery of steam from the steam generator.

By controlling the delivery of steam from the steam generator according to the distance between the steamer head and the garment, steam can be supplied as-needed to the garment, with associated water and energy consumption benefits. Moreover, the requirement for the user to, for instance, maintain pressure on a push button in order for steam to be delivered to the garment is obviated.

Preferably, the steamer head comprises a front plate having steam vents for expelling steam, and the laser sensor is arranged on the front plate.

This means that steam is expelled in the direction of the garment from which the distance to the steamer head is measured.

Preferably, the laser sensor is mounted in a casing having a front surface, the front surface:

- being flush with the front plate, or

- being recessed from the front plate.

Mounting the laser sensor in this manner assists to ensure correspondence between the measured distance and the distance between the garment and the area of the steamer head from which steam is expelled. Moreover, if the front surface is recessed from the front plate 106, this prevents protruding edge catching onto garment as well as enables the front plate to contact well with garment being treated.

In one example, the control means are adapted to stop the delivery of steam from the steam generator if the distance is larger than a given distance threshold, and allow the delivery of steam from the steam generator if the distance is smaller than the given distance threshold.

Thus, steam is only supplied once the steamer head is within range of the garment.

Alternatively or additionally, the control means are adapted to allow the delivery of steam with a first steam rate from the steam generator if the distance is within a first range of distance, and allow the delivery of steam with a second steam rate from the steam generator if the distance is within a second range of distance. The first steam rate in this example is different from the second steam rate.

This enables enhanced control over the amount of steam being supplied to the garment. Preferably, the control means are adapted to turn-off an electrical supply to the steam generator if the distance remains the same during a certain time duration.

In this way, the laser sensor can be used to determine when the garment steamer is idle and should be turned off to conserve water and energy.

Preferably, the control means are adapted to generate a visual and/or sound information based on the distance.

Such visual and/or sound information can guide the user to use the garment steamer in a safe and effective manner.

In an embodiment, the control means comprise a pump to carry water from a water source to the steam generator, and a microcontroller to actuate the pump based on the distance.

Thus, the control means control the production of steam by the steam generator based on the distance measured via the laser sensor.

In another embodiment, the control means comprise an electronic valve to control the flow of steam from the steam generator, and a microcontroller to actuate the electronic valve based on the distance.

When the garment steamer comprises the casing, the casing preferably comprises a cover window.

The cover window can act as a barrier to protect the laser sensor, e.g. from dust and condensed water.

Preferably, the cover window has a thickness which is less than 2.0 mm, and more preferably equal or less than 1.5 mm.

This maximum thickness of the cover window limits attenuation of light passing out of/into the laser sensor. Also, limiting the thickness of the cover window allows minimizing internal light reflection/refraction, and thus reducing the noise or false sensing. Preferably, the laser sensor comprises an optical sensing element, an air gap being arranged between the optical sensing element and the cover window.

This air gap prevents any contact between the optical sensing element and the cover window, which facilitates the mounting of the cover window in the steamer head.

Preferably, the air gap is equal or less than 0.5 mm, and more preferably equal or less than 0.3 mm.

This relatively small value of the air gap helps to minimise internal reflection of laser light from the cover window itself that would otherwise happen with larger value for the air gap.

Preferably, a rubber gasket is arranged between the casing and the front plate, or between a front plate holder of the steamer head and the front plate.

This rubber gasket assists to insulate the laser sensor from the heat of the front plate during use of the garment steamer. This may lessen the risk of the sensing capability of the laser sensor being compromised by the elevated temperatures within the steamer head, and may also lessen the risk of heat-damage to the laser sensor.

Preferably, the laser sensor is a time-of-flight laser sensor.

Such a time-of-flight laser sensor can be readily assembled into the steamer head, and is less prone to interference by ambient light. Moreover, such a time-of-flight laser sensor can benefit from being relatively insensitive to the different colours and reflectance properties of different fabric types.

Detailed explanations and other aspects of the invention will be given below.

BRIEF DESCRIPTION OF THE DRAWINGS

Particular aspects of the invention will now be explained with reference to the embodiments described hereinafter and considered in connection with the accompanying drawings, in which identical parts or sub-steps are designated in the same manner: Figs.1 A to ID provide views of a steamer head of a garment steamer according to an example;

Figs. 2A to 2J depict a sequence of assembly steps used to fabricate the steamer head shown in Figs. 1 A to ID;

Fig. 3 provides a cutaway view of part of the steamer head shown in Figs. 1 A to ID;

Fig. 4 provides a cross-sectional view of the steamer head shown in Figs. 1 A to ID;

Fig. 5 A provides an enlarged view of a part of the steamer head shown in Fig. 4;

Fig. 5B provides an alternative embodiment of Fig. 5 A;

Fig. 6 provides a block diagram of a garment steamer according to an example;

Fig. 7 provides a block diagram of a garment steamer according to another example;

Fig. 8 provides a block diagram of a garment steamer according to a further example;

Fig. 9 provides a flowchart of a steam generator control method according to an example;

Fig. 10 schematically depicts approach of a sensor of the garment steamer towards a fabric for illustrating the control method of Fig. 9;

Fig. 11 provides a flowchart of a steam generator control method according to another example;

Figs. 12A and 12B schematically depict approach of a sensor of the garment steamer towards a fabric for illustrating the control method of Fig. 11;

Fig. 13 provides a flowchart of a steam generator control method according to yet another example;

Figs. 14A and 14B schematically depict approach of a sensor of the garment steamer towards a fabric for illustrating the control method of Fig. 13; and

Fig. 15 provides a flowchart of a steam generator control method according to a further example.

DETAILED DESCRIPTION OF THE INVENTION

Provided is a garment steamer comprising a steam generator for generating steam, and a steamer head comprising a laser sensor for measuring the distance between the steamer head and a garment placed in front the laser sensor. The garment steamer further comprises control means configured to control, based on the measured distance, the delivery of steam from the steam generator. Figs. 1A to ID depict a steamer head 100 of a (handheld) garment steamer for treating a garment. The garment steamer also comprises a steam generator 102 for generating steam.

In this example, the steam generator 102 is included in the steamer head 100. Water can be pumped to the steamer head 100 from a water tank arranged in the steamer head, or alternatively from a water source (not visible) in a base unit which is separate from the steamer head 100, and the steam generator 102 evaporates the water supplied thereto in order to generate the steam for treating garments. In this example, the water can be supplied to the steamer head 100 via a tube between the water source and the steamer head 100.

In another example, the steam generator 102 is included in a base unit of the garment steamer which is separate from the steamer head 100. In this case, the garment steamer corresponds to a so-called stand garment steamer. The steam generated by the steam generator 102 is supplied, via a suitable thermally robust hose, to the steamer head 100. In addition to the steam generator in the base, the garment steamer may also comprise a second steam generator in the steamer head.

The steamer head 100 comprises a laser sensor 104 for measuring the distance between the steamer head 100 and a garment placed in front the laser sensor 104.

Any suitable laser sensor 104 can be used. The laser sensor 104 can operate based on a principle of light reflectance from the garment. In this case, an optical element included in the laser sensor 104 has a laser light source, such as a laser diode, which transmits light towards the garment. The sensing element also comprises a light sensor for sensing the light reflected back from the garment.

The laser light transmitted and sensed by the laser sensor 104 can have any suitable wavelength. Infra-red wavelengths, between 700 nm and 1 mm, e.g. about 940 nm, are preferred because the ranging provided by the laser sensor 104 is less sensitive to the visible colour and visible light reflectance properties of different fabric types.

Preferably, the laser sensor 104 is a time-of-flight laser sensor 104. This type of laser sensor 104 operates by transmitting light pulses towards a target, e.g. a garment or fabric, which light pulses are reflected back to the laser sensor 104 from the target. By computing the time-of- flight of the light pulses, the proximity of the target relative to the laser sensor 104 can be determined.

Such a time-of-flight laser sensor 104 can also be readily assembled into the steamer head 100, is minimally prone to interference by ambient light, and benefits from being relatively insensitive to the different colours and reflectance properties of different fabric types.

An example of a suitable time-of-flight laser sensor 104 is the VL53L0X time-of-flight laser sensor from ST Micro-electronics. This time-of-flight laser sensor 104 comprises a vertical- cavity surface-emitting laser as the laser diode-based laser light source.

Preferably, the steamer head 100 is configured to maintain an operating temperature of the laser sensor 104 of 50°C to 70°C, such as 60°C. This may enable optimal performance of the laser sensor 104, e.g. the time-of-flight laser sensor 104.

The garment steamer also comprises control means (not visible in Figs. 1A to ID) to control, based on the measured distance, the delivery of steam from the steam generator 102. The control means will be described in more detail herein below with reference to Figs. 6 to 15.

In the example shown in Figs. 1A to ID, the steamer head 100 comprises a front plate 106 having steam vents 108 for expelling steam.

The front plate 106 may be formed from any suitable material, such as a metal or metal alloy. A coating, e.g. a sol-gel-type coating, can optionally be applied to such a metallic front plate 106. The treatment surface of the front plate 106 which comes into contact with the fabric being treated may therefore be defined by a surface of such a coating.

The laser sensor 104 is arranged on or within the front plate 106. By arranging the laser sensor 104 on or in the front plate 106 in which the steam vents 108 are provided, steam is advantageously expelled in the direction of the garment from which the distance to the steamer head 100 is measured. Moreover, this configuration assists to avoid the sensing region of the laser sensor 104 no longer facing and sensing a garment when the user is positioning the steamer head 100 in order to steam extremities of the garment. As shown in Figs. 1 A, 1C, and ID, the front plate 106 (at least partly) delimits an aperture 110 in which the laser sensor 104 is located.

The laser sensor 104 is preferably mounted in a casing 112, 114 having a front surface, the front surface:

- being flush with the front plate 106, or

- being recessed from the front plate 106. For example the recess is in the order of a millimetre.

Mounting the laser sensor 104 in this manner assists to ensure correspondence between the measured distance and the distance between the garment and the area of the steamer head 100 from which steam is expelled. Moreover, if the front surface is recessed from the front plate 106, this prevents protruding edge catching onto garment as well as enables the front plate to contact well with garment being treated.

In the example shown in Figs. 1A to ID, the casing 112, 114 comprises a sensor holder 112 and a cover window 114. The laser sensor 104 is mounted in the sensor holder 112, and the cover window 114 is placed over the sensor holder 112. In this case, an outer surface of the cover window 114 is flush with the treatment surface of the front plate 106.

At least a portion of the cover window 114 is optically transmissive for the wavelengths of light transmitted and received by the laser sensor 104 in order for the distance to be measured between the steamer head 100 and the garment. For example, the cover window 114 has an optical transmissivity of greater than 80%, and more preferably greater than 90%, at such light wavelengths. This assists to minimise distortion of photon beams transmitted from/reflected to the laser sensor 104.

In order to maximise the transmissivity of the cover window 114, its thickness is minimised, preferably equal or less than 2.0 mm, more preferably equal or less than 1.5 mm, such as between 0.5 mm and 1.5 mm, e.g. about 1.0 mm. Also, limiting the thickness of the cover window allows minimizing internal light reflection/refraction, and thus reducing the noise or false sensing.

The cover window 114 is preferably a glass cover window 114. The glass for the glass cover window 114 is selected according to its robustness, particularly at the temperatures of the front plate 106 during use of the garment steamer, and optical transmissivity. For example, Gorilla® glass from Coming, Inc. has been found to be suitable for such a glass cover window 114.

Preferably, a rubber gasket 116 is arranged between the casing 112, 114 and the front plate 106, or between a front plate holder 122 of the steamer head and the front plate 106.

This rubber gasket 116 may assist to insulate the laser sensor 104 from the heat of the front plate 106, which can have a temperature of more than 100°C, such as for example around 130°C, during use of the garment steamer. This may lessen the risk of the sensing capability of the laser sensor 104 being compromised by the elevated temperatures within the steamer head 100, and may also lessen the risk of heat damage to the laser sensor 104.

In the example shown in Figs. 1 A to ID, the rubber gasket 116 serves the additional purpose of insulating a housing assembly 118A, 118B of the steamer head 100 from the front plate 106 during use of the garment steamer. Such heat insulation assists to minimise heat transfer from the front plate 106 to a handle portion 120 of the housing assembly 118A, 118B which is grasped by the user. In this example, the rubber gasket to insulate the laser sensor and the steamer head housing from the front plate is integrally formed. In another example, two separate rubber gasket may be used.

The rubber gasket 116 also serves the purpose of sealing the steamer head 100 to minimise water leakage between the front plate 106 and the housing assembly 118 A, 118B.

The rubber gasket 116 can be formed from any suitable thermally resistant elastomeric material, such as silicone rubber.

The material from which the housing assembly 118A, 118B can be formed is not particularly limited. The housing assembly 118A, 118B is preferably formed from a plastic, such as polypropylene or polybutylene terephthalate, to assist in making the steamer head 100 more lightweight.

As shown in Figs. 1A and IB, the housing assembly 118A, 118B is defined in this example by a first housing part 118A and a second housing part 118B. The internal components of the steamer head 100, and in particular the steam generator 102, are enclosed by the first housing part 118A and the second housing part 118B of the housing assembly 118A, 118B, together with the front plate 106.

The front plate 106, together with the rubber gasket 116, is assembled onto the housing assembly 118A, 118B via a front plate holder 122. In this example, the sensor holder 112 is also mounted on the front plate holder 122.

Fig. ID provides a view of the separate components of the steamer head 100. The front plate holder 122 comprises a recessed region 124 in which the sensor holder 112 is received during assembly of the steamer head 100. As shown in Fig. ID, the recessed region 124 is shaped and dimensioned to complement the profile of the sensor holder 112.

The view provided in Fig. ID shows part of the steam generator 102, and in particular the steam distribution plate 126 of the steam generator 102 in which steam channels 128 are defined. Each of the steam channels 128 aligns with a respective steam vent 108 of the front plate 106 when the steamer head 100 is assembled.

In the example shown in Figs. 1A to ID, the steamer head 100 comprises a user interface 130, in this case in the form of a push button. The control means and the laser sensor 104 enable control over the steam delivered by the steam generator 102 without requiring such a push button 130 to be continuously pressed when steam is required. But additionally providing a user interface 130 enables further options for controlling the garment steamer.

For example, the control means can be triggered to initiate the (automated) control over the delivery of steam from the steam generator 102 based on the measured distance, by a user input entered via the user interface 130, e.g. a single press and release of the push button 130.

This could improve the safety of the garment steamer because the automatic steam control is only initiated once the user has entered the input via the user interface 130. This could assist to mitigate the risk that a body part of the user, e.g. a hand, in front of the front plate 106 accidentally causes steam to be delivered towards the body part.

In another example, the garment steamer is configured to permit manual control over the steam delivery from the steam generator 102 in a first mode, e.g. by continuously pushing the push button 130, and the above-described control over the steam delivery in which the control means controls the delivery of steam from the steam generator 102 based on the measured distance in a second mode.

The user interface 130 may, for instance, be configured to enable the user to select either the first mode or the second mode.

As shown in Figs. 1A to ID, an electrical connection 132, e.g. electrical wiring, extends from the laser sensor 104. This electrical connection 132 carries sensor signals from the laser sensor 104 to the control means, e.g. to a microcontroller included in the control means.

Figs. 2A to 2J depict a sequence of assembly steps used to fabricate the above-described steamer head 100.

Fig. 2A shows mounting of the laser sensor 104 in the sensor holder 112. In this example, the sensor holder 112 delimits an opening 134 which aligns with an optical sensing element 136 included in the laser sensor 104. The optical sensing element 136 transmits light towards the garment and receives light returning from the garment. Providing the opening 134 in the sensor holder 112 assists to minimise blocking or attenuation of the light passing out of or into the sensing element 136 by the sensor holder 112.

The optical sensing element 136 is preferably mounted on a printed circuit board (PCB) 138. As shown in Fig. 2A, the sensor holder 112 includes a cavity 140 in which the PCB 138 is accommodated.

Once the laser sensor 104 is received in the cavity 140, remaining space in the cavity 140 is preferably filled with a suitable thermal padding to minimise the risk of the sensing capability of the laser sensor 104 being compromised by the elevated temperatures within the steamer head 100. Such thermal padding may also protect the laser sensor 104 from thermal damage.

A resin, such as silicone paste, can provide such thermal padding and also assist to secure the laser sensor 104 within the cavity 140. Also evident in Fig. 2A are holes 142 which enable the sensor holder 112 to be fastened to the front plate holder 122 via suitable fasteners 144, e.g. screws. This fastening is shown in Fig. 2B. Thus, the sensor holder 112, whilst holding the laser sensor 104, is secured to the front plate holder 122. This affords the front plate holder assembly shown to the right of the arrow in Fig. 2B.

Fig. 2C depicts covering of the optical sensing element 136 of the laser sensor 104 with the cover window 114. The arrows in Fig. 2D represent securing of the cover window 114 over the optical sensing element 136 by filling a groove or grooves 146 around the cover window 114 with a suitable adhesive or resin, such as silicone paste or epoxy resin.

Preferably, the cover window 114, as shown in Fig. 2E, has an optically transmissive region 148, which optically transmissive region aligns with the optical sensing element 136 when the cover window 114 is secured over the laser sensor 104, and a non-transmissive region 150 surrounding the optically transmissive region 148. The non-transmissive region 150 may assist to improve the performance of the laser sensor 104 by blocking extraneous light which would otherwise interfere with the sensing of the reflected light returning to the optical sensing element 136 from the garment.

The non-transmissive region 150 can, for example, be provided by painting the cover window 114, other than in the optically transmissive region 148, with an opaque, e.g. black, paint.

Fig. 2F shows the cover window 114 assembled onto the front plate holder assembly.

In Fig. 2G, the rubber gasket 116 is assembled onto the front plate holder 122. The rubber gasket 116 (at least partly) delimits an open area 152 in which the cover window 114 is received. Thus, the rubber gasket 116 does not block light from exiting and entering the optical sensing element 136 of the laser sensor 104.

Fig. 2H shows the front plate 106 being assembled onto the rubber gasket 116. The cover window 114 is received within an aperture 110 provided in the front plate 106, as previously described. The steam generator 102 is affixed to the front plate holder 122, as shown in Fig. 21, which affords a steam generator assembly. The steam generator assembly is subsequently enclosed between the first housing part 118A and the second housing part 118B of the housing assembly 118 A, 118B, as shown in Fig. 2J.

There is preferably no direct contact between the steam generator 102 and the laser sensor 104, such that heat transfer is mostly by radiation instead of conduction. Maximising the distance between the laser sensor 104 and the steam generator 102 assists to keep such heat transfer to a minimum.

Fig. 3 provides a cutaway view of part of the steamer head 100. The steam generator 102 in this example has a steam generator cover 154. With this arrangement, only a relatively small degree of radiation heat transfer, as represented by the arrow 156 in Fig. 4, is provided from the steam generator 102 to the laser sensor 104. This may assist the laser sensor 104 to operate within its intended/specified temperature range.

As illustrated in Fig. 4 and Fig. 5B, there are shown shows areas 158A, 158B for example made of the resin, e.g. silicone paste or epoxy resin, used to adhere the cover window 114 to the front plate holder 122. In other examples, the cover window 114 is directly adhered to the sensor holder 112.

Preferably, a tolerance 160 of 0.5 mm to 1 mm is provided between the front plate 106 and the cover window 114. This may assist to prevent that thermal expansion of the front plate 106 impinges on or damages the cover window 114.

Fig. 5A provides an enlarged view (rotated by 90 degrees) of a part of the steamer head shown in Fig. 4.

An air gap 162 is arranged between the (top of the) optical sensing element 136 and the cover window 114. Preferably, the (thickness of the) air gap is equal or less than 0.5 mm, more preferably equal or less than 0.3 mm. Elements 158A and 158B are arranged between the front plate holder 122 and the cover window 114. The air gap is determined in particular by the following parameters: - the spacing 164 between the front plate holder 122and the cover window 114, which is determined by the thickness of elements 158A and 158B,

- the cumulated thickness of PCB 138 and the optical sensing element 136.

The thickness 166 of the cover window 114 is also preferably less than 2.0 mm, and more preferably equal or less than 1.5 mm, as previously described.

Thus, in a preferred embodiment, the combined depth 164, 166 of the air gap and the cover window 114 is less than 2.0 mm. This may minimise internal reflection and attenuation of the light passing out of and into the optical sensing element 136 of the laser sensor 104.

Fig. 5B provides an alternative embodiment of Fig. 5 A.

Fig. 5B differs from Fig. 5A in that elements 158A and 158B are arranged between the sensor holder 112 and the cover window 114.

Fig. 6 provides a block diagram of a garment steamer 200 according to an example. The garment steamer 200 comprises the laser sensor 104, and the control means 202 A, 204A.

The laser sensor 104 is for measuring the distance between the steamer head 100 and a garment placed in front the laser sensor 104, as previously described. The control means 202 A, 204 A are configured to control, based on the measured distance, the delivery of steam from the steam generator 102.

In the example of Fig. 6, the control means 202A, 204A comprise a pump 204A to carry water from a water source to the steam generator 102, and a microcontroller 202 A configured to actuate the pump 204A based on the measured distance.

The pump 204A and the water source in this example are preferably provided in a base unit which is separate from the steamer head 100. In this case, a cord carrying a water tube connects the base unit to the steamer head 100. The cord may also carry electrical wiring between the steam head 100 and the base unit. In a handheld steamer, the pump and water source (e.g. a water tank) are integrated in the steamer head. Such electrical wiring can, for example, carry sensory signals from the laser sensor 104 to the microcontroller 202A, when the microcontroller 202A is included in the base unit.

The arrow between the block 104 corresponding to the laser sensor and the block 202 A representing the microcontroller denotes the transfer of sensory signals or data from the laser sensor 104 to the microcontroller 202 A.

Similarly, the arrow between the block 202A corresponding to the microcontroller and the block 204A representing the pump denotes control signals which control the actuation of the pump 204 A. Controlling the supply of water pumped to the steam generator 102 by the pump 204A based on the distance measured between the steamer head 100 and the garment enables convenient control over the delivery of steam from the steam generator 102.

Fig. 7 provides an alternative example in which the control means 202B, 204B comprise an electronic valve 204B configured to control the flow of steam from the steam generator 102, and a microcontroller 202B to actuate the electronic valve 204B based on the measured distance.

In this example, the delivery of steam from the steam generator 102 is thus controlled by the electronic valve 204B controlling the flow of steam from the steam generator 102, as opposed to the control over the production of steam described above in relation to the example of Fig. 6.

Fig. 8 provides a block diagram of an exemplary garment steamer 200. In this example, the steamer head 100 of the garment steamer 200 comprises a first power supply 206 which supplies power to the laser sensor 104, an auxiliary controller 208, and a first communications module 210.

The garment steamer 200 shown in Fig. 7 further comprises a base unit 212. The base unit 212 comprises a second power supply 214 which supplies power to a main controller 216, a steam generator driving and control circuit 218, and a second communications module 220.

The first communications module 210 and the second communications module 220 communicate with each other, as represented in Fig. 7 by the double-headed arrow therebetween, such that sensory signals or data from the laser sensor 104 of the steamer head 100 are communicated to the main controller 216 and the steam generator driving and control circuit 218. The latter may then provide control signals for controlling the delivery of steam by the steam generator 102 according to the measured distance between the steamer head 100 and the garment, as previously described.

Thus, at least some of the processing of the sensory data is implemented in the main controller 216 and the steam generator driving and control circuit 218 in the base unit 212. But by also at least partially processing the sensory data using the auxiliary controller 208 in the steamer head 100, and transmitting the thus processed data to the main controller 216 in the base unit 212, noise can be reduced relative to the scenario in which all processing of the sensory data is performed within the base unit 212.

Exemplary control methods for controlling the delivery of steam by the steam generator 102 will now be described with reference to Figs. 9 to 15. Such methods are implementable via a suitably configured controller, such as the microcontrollers 202A, 202B described above in relation to Figs. 6 and 7.

In other words, the controller can be pre-programmed with a suitable algorithm to control the above-described pump 204A or electronic valve 204B according to the measured distance of the steamer head 100 from the garment, with reference to one or more given threshold distances.

When, for example, the garment steamer 200 is switched on, the proximity sensor, e.g. the laser sensor 104, can automatically compute the target distance between the steamer head 100 and the garment/fabric up to a range of 2 metres in less than 30 ms.

Fig. 9 provides a flowchart of a control method 300 according to a first example. In operation box 302, the distance between the steamer head 100 and the garment is obtained via a proximity sensor, e.g. the above-described laser sensor 104.

In decision box 304 it is determined whether or not the distance is larger than a given distance threshold, such as 35 mm to 40 mm. If yes, the steam is stopped or is not delivered from the steam generator 102 in operation box 306. If no, the delivery of steam from the steam generator 102 is allowed in operation box 308. This is schematically illustrated in Fig. 10. The laser sensor 104 approaches a garment 310, and the distance D between the laser sensor 104 and the fabric 310 is determined via reflection of the transmitted light 312 from the garment 310. The reflected light 314 is reflected back towards the laser sensor 104.

Fig. 10 also shows the given distance threshold Dl. If the measured distance D is larger than the given distance threshold Dl, the steam delivery is stopped. But if the measured distance D is not larger than, in other words is equal to or less than, the given distance threshold Dl, the steam delivery is allowed.

Thus, steam is only supplied once the steamer head 100 is within range of the garment 310.

Fig. 11 provides a flowchart of another control method 316. Similarly to the control method 300 shown in Fig. 9, in operation box 302, the distance D between the steamer head 100 and the garment 310 is obtained via a proximity sensor, e.g. the above-described laser sensor 104. In decision box 304 it is determined whether or not the distance D is larger than a given distance threshold Dl, such as 40 mm. If yes, the steam is stopped or is not delivered from the steam generator 102 in operation box 306. If no, it is determined in decision box 318 whether or not the distance D is larger than a second given distance threshold which is smaller than the given distance threshold Dl.

If the distance D is larger than the second given distance threshold, the steam delivery from the steam generator 102 is implemented at a first steam rate R1 in operation box 320. If the distance D is not larger than, in other words is less than or equal to, the second given distance threshold, the steam delivery from the steam generator 102 is implemented at a second steam rate R2 which is different from the first steam rate R1.

For example, the given distance threshold Dl is 40 mm, and the second given distance threshold is 10 mm.

Preferably, the second steam rate R2 is less than the first steam rate R1 in order to lessen the risk of a greater amount of steam being supplied relatively close to the garment 310 causing damage to the garment 310. More generally, steam in this example is delivered from the steam generator 102 with the first steam rate R1 if the distance D is within a first range of distance, and with the second steam rate R2 if the distance D is within a second range of distance. This enables enhanced control over the amount of steam being supplied to the garment 310.

The control method 316 of Fig. 11 is schematically depicted in Figs. 12A and 12B. When the measured distance D is greater than the given distance threshold Dl, the steam delivery from the steam generator 102 is stopped. When the measured distance D is less than or equal to Dl, steam delivery from the steam generator 102 is allowed.

The first range of distance is defined between the given distance threshold Dl and the second given distance threshold D2. When the measured distance D is in this first range of distance, steam is delivered at the first steam rate Rl.

When the measured distance D is less than D2, in other words when the measured distance is within the second range of distance, steam is delivered at the second steam rate R2.

Fig. 13 provides a flowchart of another control method 324. Similarly to the control method 300 shown in Figs. 9 and 11, in operation box 302, the distance D between the steamer head 100 and the garment 310 is obtained via a proximity sensor, e.g. the above-described laser sensor 104. In decision box 304 it is determined whether or not the distance D is larger than a given distance threshold Dl, such as 40 mm. If yes, the steam is stopped or is not delivered from the steam generator 102 in operation box 306. If no, steam delivery is initiated in operation box 308.

It is determined in decision box 326 whether or not the distance D is larger than a third given distance threshold. If yes, first visual and/or sound information is issued to the user via a suitable (further) user interface, for example by a green light being on and a red light being off, in operation box 328. If no, second visual and/or sound information is issued to the user via the further user interface, for example by the abovementioned green light being off and the abovementioned red light being on. The first and second visual and/or sound information are different from each other. Thus, the visual and/or sound information is issued based on the measured distance D. This can guide the user to use the garment steamer 200 in a safe and effective manner, for example by indicating to the user when the steamer head 100 is too close to the fabric 310.

The control method 324 of Fig. 13 is schematically depicted in Figs. 14A and 14B. In both Figs. 14A and 14B steam delivery from the steam generator 102 is allowed because the steamer head 100 is within the given distance threshold D from the garment 310.

In Fig. 14A, the distance D is larger than the third given distance threshold D3, such that the further user interface 332A issues the first visual and/or sound information.

In Fig. 14B the distance D is less than the third given distance threshold D3, such that the further user interface 332B issues the second visual and/or sound information.

Fig. 15 provides a flowchart of another control method 334. Similarly to the control method 300 shown in Figs. 9, 11, and 13, in operation box 302, the distance D between the steamer head 100 and the garment 310 is obtained via a proximity sensor, e.g. the above-described laser sensor 104. In decision box 304 it is determined whether or not the distance D is larger than a given distance threshold Dl, such as 40 mm. If no, steam delivery is initiated in operation box 308.

If yes, the steam is stopped or is not delivered from the steam generator 102 in operation box 306, and it is determined in decision box 336 whether or not the steam delivery has been stopped for a certain time duration, e.g. 10 minutes. If yes, the electrical supply to the steam generator 102 is tuned off in operation box 338.

In this way, the proximity sensor, e.g. the laser sensor 104, can be used to determine when the garment steamer 200 is idle and should be turned off to conserve water and energy.

Whilst the above-described control methods, such as the control methods 300, 316, 324, and 334 respectively depicted in Figs. 9, 11, 13 and 15, can be effectively implemented using the laser sensor 104, e.g. the time-of-flight laser sensor 104, described above. Alternative proximity sensors may also be employed in such methods, such as ultrasonic proximity sensors. The above embodiments as described are only illustrative, and not intended to limit the technique approaches of the present invention. Although the present invention is described in details referring to the preferable embodiments, those skilled in the art will understand that the technique approaches of the present invention can be modified or equally displaced without departing from the protective scope of the claims of the present invention. In particular, although the invention has been described based on a garment steamer, it can be applied to any household appliance which can be brought into proximity with a surface to which steam is to be applied by the household appliance. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. Any reference signs in the claims should not be construed as limiting the scope.