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Title:
METHOD AND APPARATUS FOR REMOVING A STAIN FROM A TARGET OBJECT
Document Type and Number:
WIPO Patent Application WO/2012/073150
Kind Code:
A2
Abstract:
A method of removing a stain from a target object and an apparatus therefor are provided. The method comprises the steps of: placing a light source at a preset distance from the stain; illuminating the stain with light having a wavelength in the range of [400nm, 500nm] generated by the light source, wherein the light generated has a preset light intensity at the surface of the stain. With the illumination of the light source having a wavelength in the range of[400nm, 500nm], some stains, i.e. stains caused by food, can be removed from some target objects, i.e. fabrics.

Inventors:
GOTTENBOS BART (NL)
BRAUN DOREEN (NL)
Application Number:
PCT/IB2011/055223
Publication Date:
June 07, 2012
Filing Date:
November 22, 2011
Export Citation:
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Assignee:
KONINKL PHILIPS ELECTRONICS NV (NL)
GOTTENBOS BART (NL)
BRAUN DOREEN (NL)
International Classes:
D06L4/50
Foreign References:
US6300299B12001-10-09
US20070032842A12007-02-08
JP2010227184A2010-10-14
Other References:
None
Attorney, Agent or Firm:
KROEZE, John et al. (Building 44, AE Eindhoven, NL)
Download PDF:
Claims:
What is claimed is:

1. A method of removing a stain from a target object, the method comprising the steps of: a) placing a light source at a preset distance from the stain;

b) illuminating the stain with light having a wavelength in the range of [400nm, 500nm] generated by the light source, wherein the light generated has a preset light intensity at the surface of the stain.

2. The method of claim 1, further comprising the step of:

c) wetting the target object.

3. The method of claim 2, further comprising the steps of:

d) setting a timer for the duration of the illumination depending on the type of stain; e) shutting off the light source to stop the illumination when the timer expires.

4. The method according to any one of claims 1 to 3, wherein the preset light intensity is not less than 50W/cm2.

5. The method according to any one of claims 1 to 3, wherein the preset light intensity is set depending on the type of stain.

6. The method according to any one of claims 1 to 3, wherein the light source comprises a blue LED.

7. The method of claim 6, wherein the blue LED is configured to generate light having a wavelength of 460nm.

8. The method of claim 6, further comprising the step of:

f) setting the power of the light source depending on the size of the stain.

9. An apparatus for removing a stain from a target object, the apparatus comprising:

- a light source, configured to generate light having a wavelength in the range of

[400nm, 500nm];

- a support, configured to set the distance between the light source and the stain;

wherein the light source is further configured to generate light to illuminate the stain with a preset light intensity at the surface of the stain.

10. The apparatus of claim 8, wherein the light source comprises at least one blue LED.

11. The apparatus of claim 9, wherein the blue LED is configured to generate light having a wavelength of 460nm.

12. The apparatus of claim 9, wherein the light source is further configured to generate light with an intensity depending on the size of the stain.

13. The apparatus of claim 9, wherein the preset light intensity is not less than 50W/cm2.

14. The apparatus of claim 12, wherein the preset light intensity is set depending on the type of stain.

15. The apparatus of claim 8, further comprising:

- a sprayer, configured to spray fluid to wet the target object.

Description:
METHOD AND APPARATUS FOR REMOVING A STAIN FROM A

TARGET OBJECT

Technical field

The invention relates to stain removal, in particular, to a method of removing a stain from a target object and an apparatus therefor.

Background of the invention

Some stains, most notably those caused by some foodstuffs, for example carrot and spinach, are difficult to be removed by the laundry or the washing machine.

No light treatment devices for these food-caused stains are currently known.

Summary of the invention

Clothes are often bleached in the sun. And recently, it has been discovered that various stains caused by foodstuffs such as, for example carrots, spinach, tomatoes, berries or wine etc., can be almost completely removed by the sun, whereas they are difficult to be removed at the laundry.

The inventors have performed some experiments to mimic the effect by utilizing artificial light. Although most people ascribe the bleaching effect of the sun to the UV part of the sunshine, said experiments have revealed that the UV part of the sunshine is less of a key factor in removing the food-caused stain, maybe because those foodstuffs, e.g. carrots or spinach, absorb predominantly some lower visible wavelengths, i.e. 400-500nm. And some other wavelengths, in the neighborhood of [400nm,500nm], resulting from a violet LED array, also work for stains caused by spinach etc., but are less energetic than that of a Blue LED Array. Therefore, with a wavelength of around 460nm, blue LEDs may act as an effective light source in a device for removing, by illumination, some stains caused by some foodstuffs. And as hitherto no device has been available that can mimic this effect, such a light treatment device would be very handy for stain removal, especially when the sunshine is not available.

In view of the lack of handy and effective means for removing food-caused stains, it would be advantageous to achieve a method of removing a stain from a target object and an apparatus therefor. According to an embodiment of the invention, there is provided a method of removing a stain from a target object, the method comprising the steps of:

placing a light source at a preset distance from the stain;

illuminating the stain with light having a wavelength in the range of [400nm, 500nm] generated by the light source, wherein the light generated has a preset light intensity at the surface of the stain.

With the illumination of light having a wavelength in the range of [400nm, 500nm], some stains, for example food-caused stains, can be removed from target objects, for example, fabrics.

And, according to another embodiment of the invention, there is also provided an apparatus for removing a stain from a target object, the apparatus comprising:

a light source, configured to generate light having a wavelength in the range of [400nm, 500nm];

a support, configured to set the distance between the light source and the stain;

wherein the light source is further configured to generate light to illuminate the stain with a preset light intensity at the surface of the stain.

Advantageously, the apparatus further comprises a sprayer, configured to spray fluid to wet the target object.

With the fluid, for example water, provided by a sprayer, a stain may be more easily removed from the target object.

Brief description of the drawings

Other features, objects and advantages of the present invention will be more apparent by reference to the following detailed description of non-limited exemplary embodiments, when taken in conjunction with the accompanying drawings:

Fig. 1 illustrates a cross-sectional side view of an apparatus for removing a stain according to an embodiment of the present invention;

Fig. 2 illustrates a bottom view of an apparatus for removing a stain according to an embodiment of the present invention;

Fig. 3 illustrates another cross-sectional side view of an apparatus for removing a stain according to another embodiment of the present invention;

Fig. 4 illustrates a flowchart of the method of removing a stain from a target object according to an embodiment of the present invention;

Fig. 5 illustrates a further step of the method of removing a stain from a target object according to another embodiment of the present invention;

Fig. 6 illustrates the stain-removing effect over illumination time in a test conducted with the apparatus of Fig.3;

Same or similar reference signs refer to same or similar apparatuses or circuits.

Detailed description of the embodiments

Fig. 1 illustrates a cross-sectional side view of an embodiment of an apparatus for removing a stain according to the invention. As shown in Fig. 1, the apparatus 10A for removing a stain 101 from a target object 100 comprises a light source 11 and a support 12.

Fig. 2 illustrates a bottom view of an embodiment of the apparatus of Fig. 1.

The light source 11 is configured to generate light having a wavelength in the range of [400nm, 500nm]. And the support 12 is configured to set the distance between the light source 11 and the stain 101 so as to achieve an appropriate light intensity and illumination area on the surface of the stain 101, wherein the light source 11 is further configured to generate light to illuminate the stain with a preset light intensity at the surface of the stain 101. And the light source 11 emits light towards the stain 101 in a divergent manner as illustrated by the directional arrow in Fig. 1.

Optionally, the apparatus 10A may further comprise a timer configured to set a predefined duration, wherein the light source 11 illuminates the stain 101 for a time which is neither shorter nor longer than said predefined duration.

Optionally, the light source 11 may comprise at least one blue LED.

In some of the above embodiments, the light source 11 is further configured to generate light of an intensity depending on the size of the stain 101. For example, if the stain 101 occupies a relatively large area on the fabric 100, then the distance between the light source 11 and the stain 101 may be adjusted so as to achieve a spot size 15, resulting from the illumination by the light source 11, that fully covers the stain 101. And accordingly, the intensity of the light source 11 may be set to be higher to ascertain that the light intensity at the surface of the stain 101 is strong enough. And, of course, the adjustment of the distance between the light source 11 and the stain 101 may be achieved by utilizing the support 12.

Preferably, the preset light intensity is not less than 50W/cm 2 , so that the stain 101 may be removed in a relatively short time.

It is appreciated that the above-mentioned light intensity generally means the light intensity at the surface of the target object, for example a fabric, and that is the light intensity at the position of the stain. Generally, the light intensity may depend on the amount of light power emitted by the light source and the spot size. As LEDs have a divergent light beam, the spot size may depend on the divergence angle and the distance of the LED (or other divergent light source) from the fabric. The experiments are, for example, done with LEDs with a light output power of 700mW and a divergence angle of 120degrees. In the experiment, the distance between the light source and the stain is approximately 5mm, leading to a spot size of 17.3mm diameter and a spot area of 2.4cm 2 , and thus an average intensity of approximately 300mW/cm 2 . The intensity of 50mW/cm 2 can therefore be easily achieved with currently available LEDs.

For the apparatus 10A, preferably, the preset light intensity is set depending on the type of stain. If stain 101 is found to be stubborn, for example because the stain is caused by red fruit, such as wine, berries, then the preset light intensity may be set to a high value, for example 90W/cm 2 . And if the stain 101 is less stubborn, for example because the stain is caused by spinach, carrots, or tomatoes, which apparently are more sensitive to light, then, a light intensity of 50W/cm 2 may be enough for removing the stain.

Fig. 3 illustrates a cross-sectional side view of another embodiment of an apparatus for removing a stain according to the invention. As shown in Fig. 3, the apparatus 10B may further comprise a sprayer 13 which is configured to spray fluid 14, for example water, to wet the target object 100 (i.e. a fabric with the stain 101).

The use of the apparatus 10B is simple. For example, when clothes are taken out of the washing machine and it is noticed that a stain, for example a food-caused stain, has not been removed, then the wet clothes are put on a table and the apparatus 10B is placed over them. The light source 11 is switched on, positioned well on the stain 101, and after a certain time the stain is checked. If it is still present, the treatment may be continued. And if the clothes are dry and the stain is still not gone, the sprayer 13 can be configured to spray some water to rewet the stain 101 so as to continue the stain-removing treatment effectively.

Fig. 4 illustrates the flowchart of the method of removing a stain from a target object according to an embodiment of the invention. As shown in Fig. 4, the method comprises the steps SI and S2. In step SI, a light source is placed at a preset distance from the stain.

In step S2, the stain is illuminated with light having a wavelength in the range of [400nm, 500nm] generated by the light source, wherein the light generated has a preset light intensity at the surface of the stain.

Fig. 5 illustrates a further step S3 of the method of removing a stain from a target object according to another embodiment of the present invention.

In step S3, wetting of the target object is performed.

And, in some cases, in cooperation with Step S3, the illumination of step S2 can have a better stain-removing effect. And, if the stain is still not completely removed after the illumination of step S2, optionally, just perform step S3 again to rewet the target object with the stain. And then go on with the illumination by step S2, as indicated by the dotted-line arrow in Fig. 4.

To get a desired duration of the illumination in step S2, in some embodiments, the method of removing the stain from the target object further comprises 2 additional steps: Setting a timer for the duration of the illumination, depending on the type of stain; and Shutting off the light source to stop the illumination when the timer expires.

Prior to Step S2, according to the type of stain, a corresponding timer setting for the duration of the illumination is chosen. And when the timer expires, the light source shuts off to stop the illumination. With these 2 further steps, the illumination quantity will be neither too much nor too little for the given type of stain.

Generally, illumination with a high light intensity will help to remove the stain in a relatively short time. So, preferably, in some of the above embodiments, the preset light intensity on the stain is at least 50W/cm 2 .

It is appreciated that the preset light intensity is set depending on the type of stain. If there is a stubborn stain, for example red fruit stains (wine, berries), then the preset light intensity may be set to be a high value, for example 90W/cm 2 . And if the stain is less stubborn, for example the stain is caused by spinach, carrots or tomatoes, and is apparently more sensitive to light, then, a light intensity of 50W/cm 2 may be sufficient for removing the stain. In some experiments, according to an embodiment of the invention, a light intensity of 300mW/cm 2 allows spinach to be removed in 5 minutes, but carrot takes approximately 60 minutes. At a light intensity of 50mW/cm 2 , a corresponding illumination time needed to remove a spinach stain and a carrot stain may be approximately 30min and 6h, respectively. In some of the above embodiments, optionally, the light source may comprise a blue LED array to generate light having a wavelength in the range of [400nm, 500nm].

Optionally, some of the above embodiments may comprise still another step for setting the power of the light source in dependence on the size of the stain.

Thus, if the stain occupies a relatively large area on the fabric, then the distance between the light source and the stain may be adjusted to achieve that the spot size fully covers the stain, and accordingly, the power of the light source may be set to be higher to ascertain that the light intensity at the surface of the stain is strong enough.

Fig. 6 illustrates a stain-removing effect over illumination time in an experiment with the apparatus of Fig.3, under the experimental conditions that: target object 100, for example a T-shirt, is washed before use; food(Spinach & carrots) is put onto the T-shirt to form Spinach stain 1011 and carrot stain 1012 between which the borderline is illustrated by the dotted line in Fig.6, and the T-shirt is dried overnight; the T-shirts are washed with detergent in a short program (15min); Stain 1011 and stain 1012, which are sort of wet due to washing, are treated with the apparatus of Fig.3 at a light intensity of approximately 0.3W/cm 2 , and the light source 11 within the apparatus 10B is in the form of blue LEDs with a wavelength of 460nm.

As shown in Fig. 6, a plurality of stains are removed over increasingly longer treatment times (t=0.2 min, 5 min, 20 min, 3 hour) as illustrated in Fig.6A to Fig.6E, and finally, the stains are almost completely removed after 3 hours of illumination.

Above, the embodiments of the present invention have been described in detail, but the present invention is not limited to specific systems or devices: those skilled in the art can make various variations or modifications within the scope of the appended claims.