WO2008128900A2

WO2008128900A2 - Domestic appliance comprising a panel of a material that is at least partially transparent

Info

Publication number: WO2008128900A2
Application number: PCT/EP2008/054318
Authority: WO
Inventors: Miguel Angel BUÑUEL MAGDALENA; Rafael Cases Andreu; Jesús CEAMANOS GAYA; Carlos Vicente Mairal Serrano; Rosa Isabel Merino Rubio; Víctor Manuel ORERA CLEMENTE; Daniel Sola Martinez; José Ignacio Peña Torre
Original assignee: BSH Bosch und Siemens Hausgeräte GmbH
Priority date: 2007-04-19
Filing date: 2008-04-10
Publication date: 2008-10-30
Also published as: WO2008128900A3; ES2322006A1; ES2322006B1; EP2191201B1; EP2191201A2

Abstract

The invention relates to a domestic appliance comprising a panel (10) of a material that is at least partially transparent, said panel comprising a front or upper side (12) that is accessible to the user. To equip a domestic appliance of this type with an additional signalling function in an optically pleasing manner, a sub-region (18) of the panel (10) beneath the front or upper side (12) is provided with a luminescent material (20).

Description

Home appliance device with a pane of an at least partially transparent material

The invention is based on a domestic appliance device with a pane of an at least partially transparent material according to the preamble of claim 1 and a method for producing such a pane according to the preamble of claim 14.

In the household appliance sector, various devices with at least partially transparent panes are known. Examples include oven panes and cooktops of radiant panels or induction cooktops. The transparent material may be, for example, a glass or a glass ceramic and partially printed. Furthermore, it is known to print such transparent materials in partial areas with markings, for example in order to visualize heating zones of a hob or to achieve a typical appearance for the manufacturer. In particular, in the field of induction hobs mainly crystal glass is used for the cooking surface because of the low electrical conductivity, low thermal expansion, high temperature resistance and excellent optical properties.

Despite the advantageous properties mentioned above, however, there is still a need for further development, for example with regard to operational safety and optical differentiation possibilities in the area of cover plates for induction hobs.

The invention is in particular the object of providing generic household appliance devices in a visually appealing way with an additional signal function. The invention is based, in particular, on a household appliance device with a pane made of an at least partially transparent material, comprising a front or top side accessible to a user.

It is proposed that a portion of the disc below the front or top is provided with luminescent material. The luminescent material can be excited to illuminate in a manner which appears reasonable to the person skilled in the art and depending on the specific type of household appliance device, so that the pane can be equipped with an additional signal function. The fact that the luminescent material is not arranged on the top, which is accessible to the user, the luminescent material is protected and wear or damage to a layer of the luminescent material can be avoided.

As luminescent materials are paramagnetic ions such as 4f ions (rare earths such as Pr ³⁺ , Er ³⁺ , Nd ^3+, etc.) and 3d-ions (transition heavy metals such as Mn ²⁺ , Cr ³⁺ , Ni ^2+, etc.). into consideration. The synthesis and characterization of 4f and 3d doped silicates, fluorine tin chromates, and other glasses has been extensively studied in recent years due to their broad applicability in laser, fiber, and communication technologies. Also, the doping of building glasses with these elements has recently become the focus of research efforts, demonstrating that industrial application of the optical properties of luminescent ions is feasible.

While in the prior art, a glass ceramic has always been doped in a homogeneous manner, the invention proposes to introduce the luminescent material only in a partial region of the disc. As a result, a special effective signal function can be achieved by which differentiated information can be transmitted. In this context, a subarea should always be defined as a real subarea that does not encompass the entire disc. In a development of the invention it is proposed that the luminescent material is introduced into the transparent material. Thereby, a secure confinement of the luminescent material can be ensured, which on the one hand damage the luminescent material by scratches or the like, and on the other hand, the luminescent material does not escape.

For the household appliance area advantageous material properties such as low electrical conductivity and low thermal expansion can be ensured if the transparent material is a glass or glass ceramic material, for example, sold under the trade name "Ceran" material.

The luminescent material can be introduced in a particularly simple manner into a sharply demarcated part region if the luminescent material is printed on one of the front or top side opposite back or bottom side of the disc. For example, a screen printing technique can be used to print the luminescent material.

When the luminescent material is incorporated into a portion of the disk immediately adjacent one of the front and top surfaces opposite the back or bottom, i. E. just below the surface of the

Rear or bottom is arranged, it is on the one hand protected against access by the user from the front or top and on the other hand can be easily and selectively introduced into certain, sharply defined subregions. Furthermore, electromagnetic radiation for exciting the luminescence from the underside can be radiated, so that attenuation of the radiation by absorption in the transparent material can be minimized by a short path which the radiation has to cover in the transparent material to a minimum.

In a further development of the invention it is proposed that the luminescent

Material comprises luminescent ions which are introduced by a laser insertion process in the transparent material. By the laser storage drive the portion that is provided with the luminescent material can be flexibly adapted to the needs of the specific application, so that by means of the additional signal function of the disc clearly defined information can be transmitted, for example, a residual heat treatment, a Heizzonenausfall or similar transport.

As an alternative or in addition to the laser insertion method, the luminescent material can be introduced into recesses in the rear or underside of the disc. The recesses may be formed, for example, as in particular microscopic blind holes, which are e.g. with a laser drilling or

Laser processing methods are introduced into the back or bottom of the disc. The luminescent material can be sealed against environmental influences if the recesses filled with the luminescent material are sealed with a protective layer.

It is further proposed that the luminescent material contains rare earth ions with valence electrons in a 4f-orbital. Such ions exhibit the property that multiple infrared photons can be converted to a visible photon. This phenomenon is known as "up-conversion" and can be used, for example, in hobs with radiant heaters.

For example, if a portion of a cover of a hob associated with a heating zone is doped with Er ³⁺ ions, the infrared radiation emitted during operation of the radiant heater would excite the Er ³⁺ ions for luminescent emission of green light, thus providing a striking contrast to the conventional Red radiating radiators would be reached. The

Conspicuity of the heated heating zone can be significantly increased, so a heat heating can be made more effective.

Selective excitation of the luminescent material, depending on a desired function, can be achieved if the home appliance device has a

Light emitting diode for exciting the luminescence of the luminescent material includes. In particular, when the light-emitting diode emits ultraviolet radiation, For example, the radiation exciting the luminescence can remain invisible, which leads to a particularly clear appearance of the luminescent subregion and thus improves the signal effect. The light-emitting diode can be actuated for example by a control unit.

If the domestic appliance device comprises a control unit and a temperature sensor associated with the partial area, wherein the control unit operates the light-emitting diode depending on a signal of the temperature sensor, an effective residual heat heating can be achieved.

Even if the radiant heater no longer produces visible light, the residual heat of a heating zone can be visualized strikingly by pressing the LED.

Furthermore, the invention relates to a method for producing a pane of an at least partially transparent material for a domestic appliance device, wherein the pane comprises a front or top accessible to a user.

In order to equip the disk with an additional signal function, it is proposed that luminescent material be introduced into the transparent material in a partial area below the front or top of the disk.

According to a development of the method according to the invention, it is proposed that a powder with oxides of luminescent ions is applied to the back of the pane in the partial area and then the area is locally heated with a laser in order to diffuse the luminescent ions into the transparent material. As a result, a clearly defined subarea with luminescent material can be coded in an industrially applicable, simple manner.

It is also proposed that in the sub-area on a back of the Slice holes are made in the transparent material and the lumi- neszente material is introduced into the holes. In a particularly advantageous embodiment of the method according to the invention, the holes are closed after introduction of the luminescent material with a protective layer. The holes can be made in a flexibly configurable manner and very precisely in the back of the disk when done with a laser.

Further advantageous features of the invention will become apparent from the following description of the figures. The figures, the description and the claims contain numerous features in combination, which the person skilled in the art will also consider individually and summarize to further meaningful combinations.

Showing:

FIG. 1 shows a household appliance device in the form of a glass ceramic hob with a pane of transparent glass-ceramic material in a cutout, FIG.

FIG. 2 shows a domestic appliance device with a pane according to a first alternative embodiment of the invention, in which the luminescent material is introduced into the transparent material in a laser deposition process, and FIG

Fig. 3 shows a household appliance device according to a further alternative embodiment of the invention, in which the luminescent material is introduced into recesses in a back in the disc.

FIG. 1 shows a domestic appliance device designed as an induction glass-ceramic cooktop with a pane 10 of transparent glass ceramic material in a cutout. The disc 10 covers a cooktop which comprises four heating zones, under each of which induction heating elements, not shown here, are arranged are. The disk 10 shown in Figure 1 can also be used to cover radiant heaters.

On a user-accessible top 12 cooking pots or pans can be placed in operation, which can be heated by means of the induction heaters.

On one of the upper side 12 opposite underside 14 designed as NTC element temperature sensor 16 is arranged, which serves to regulate the operation of the induction heater. The temperature sensor 16 is arranged in the center of an annular portion 18 of the disc 10 which is provided with luminescent material 20. The luminescent material 20 is printed on the underside 14 of the disc 10 in a screen printing process.

The luminescent material 20 contains rare earth ions with valence electrons in a 4f-orbital, Er ³⁺ ions. He ³⁺ ions have a variety of possible optical transitions in their basic configuration. When Er ³⁺ ions are excited by ultraviolet light having a wavelength of about 400 nm, the ions from the ground state are excited into excited states and then a spontaneous emission of green light having a wavelength of 530 nm is generated.

On one side of the hob plate designed as a hob 10, a light emitting diode 22 is arranged, which emits ultraviolet light. The ultraviolet light is coupled into the side surfaces of the pane 10 formed of glass or glass ceramic material and passed through total reflection at the upper side 12 and at the lower side 14 into the partial area 18 equipped with luminescent material 20. The Er ³⁺ ions absorb the ultraviolet light of the light emitting diode 22 and emit green light having the wavelength of 530 nm, and the portion 18 emits green light when the light emitting diode 22 is turned on. In further embodiments of the invention, the portion 18 has other shapes such as lines, letters or the like.

The light emitting diode 22 is operated by a control unit 24, which also reads out a signal of the temperature sensor 16. In one embodiment of the invention, the control unit 24 switches on the light-emitting diode 22 whenever the temperature detected by the temperature sensor 16 is above a threshold value, for example 50 or 60 ^° C.

Figures 2 and 3 show alternative embodiments of the invention, wherein analog or identically acting features are provided with the same reference numerals. The following description is limited to differences from the embodiment shown in Figure 1, while reference is made to the description of Figure 1 with regard to the same features.

In the embodiments illustrated in FIGS. 2 and 3, the luminescent material 20 is introduced in each case into the transparent material by various methods into a region of the disc 10 which adjoins the underside 14 directly.

In the exemplary embodiment illustrated in FIG. 2, the luminescent material 20 is introduced into the transparent material by means of a laser insertion method. For this purpose, a powder with 4f ions is applied to the underside 14 of the disk 10. Subsequently, the desired portion 18 is strongly heated with a laser. As a result, the ions of the luminescent material 20 burn into the glass-ceramic material of the pane 10 or the ions diffuse under the surface of the underside 14 of the glass-ceramic material. The remaining luminescent material 20 is removed, so that only in the selected and treated with the laser portion 18 luminescent material 20 immediately below the surface of the bottom 14 remains. Figure 3 shows a further alternative embodiment of the invention, in which with a laser, a grid or grid of small, formed as blind holes recesses 26 are incorporated in the bottom 14 of the disc 10. Subsequently, the recesses 26 were filled with the luminescent material 20 and the recesses 26 filled with the luminescent material 20 were sealed with a protective layer 28 of glass.

The invention is not limited to the improvement of cover plates of hobs, but can also be applied in other household appliances. For example, the use in an oven window is conceivable. Further, different portions of the slices may be provided with various luminescent materials that may, for example, illuminate in different colors and / or that may be excited in a different manner to selectively provide different optical signals. For example, Pr ³⁺ ions can be used which are converted by ultraviolet light

Emission of yellow light from 580 to 590 nm wavelength can be excited. Further, 5f ions, such as Ce ³⁺ , which excite ultraviolet light to largely emit white light in a wide spectral range can also be used. Alternative 4f ions are Dy ^3+, Tm ^3+, Eu ^3+, Ho ³⁺ and Oxidzu- sammensetzungen such ions such as Er ₂ O ^"3, Pr ₂ ^O" 3 etc. More luminescent

Materials that can be used are quantum dots, such as AIAs, GaAs and others. Such materials are particularly useful in connection with the embodiment of the invention shown in Figure 3, are incorporated in the small recesses 26 in the back of the disc 10.

In order to avoid absorption of the ultraviolet light during transport through the disk 10, in further alternative embodiments of the invention, the ultraviolet light may be radiated onto the subregion 18 from the underside 14. When the luminescent material 20 has been deposited just below the bottom surface 14, even with a strong attenuation of the ultraviolet light in the transparent material, it can be ensured that a large part of the ultraviolet light reaches the luminescent material 20. Furthermore, the glass ceramic pane according to the invention can also exert a signal function without external illumination solely by thermoluminescence, so that infrared photons of a heat source can excite the luminescent material 20 for luminescence.

As a further effect of the luminescent material 20, suppression of 4 f -luminescence by the temperature can be used. In some luminescent materials, the luminescence disappears at a temperature above about 160 ^° C. For example, if the luminescent material 20 is applied to an inner side of an oven pane, it can be concluded from the fact that the luminescence disappears that, for example, preheating the Oven is finished.

reference numeral

10 slice

12 top

14 bottom

16 temperature sensor

18 subarea

20 material

22 LED

24 control unit

26 recess

28 protective layer

Claims

claims

A domestic appliance device comprising a disc (10) made of an at least partially transparent material, comprising a user-accessible front or top side (12), characterized in that a portion (18) of the disc (10) below the front or top side (12). is provided with luminescent material (20).

2. Domestic appliance device according to claim 1, characterized in that the luminescent material (20) is introduced into the transparent material.

3. Domestic appliance device according to one of the preceding claims, characterized in that the disc (10) is formed as a hob plate of a hob.

4. Domestic appliance device according to one of the preceding claims, characterized in that the transparent material is a glass or glass ceramic material.

5. Domestic appliance device according to one of the preceding claims, characterized in that the luminescent material (20) on one of the front or top side (12) opposite the rear or bottom side (14) of the disc (10) is printed.

6. Household appliance device according to one of the preceding claims, characterized in that the luminescent material (20) in a directly on one of the front or top (12) opposite the rear or bottom (14) adjoining region of the disc (10) is introduced ,

7. Domestic appliance device according to one of the preceding claims, characterized in that the luminescent material (20) comprises luminescent ions, which are introduced by a laser storage process in the transparent material.

8. Domestic appliance device according to one of the preceding claims, characterized in that the luminescent material (20) in recesses (26) in one of the front or top (12) opposite the rear or bottom (14) of the disc (10) are introduced ,

9. Domestic appliance device according to one of the preceding claims, characterized in that with the luminescent material (20) filled recesses (26) with a protective layer (28) are closed.

10. Domestic appliance device according to one of the preceding claims, characterized in that the luminescent material (20) contains rare-earth ions with valence electrons in a 4f-0rbital.

11. Domestic appliance device according to one of the preceding claims, characterized in that the luminescent material (20) contains He ³⁺ ions.

12. Domestic appliance device according to one of the preceding claims, characterized by a light emitting diode (22) for exciting the luminescence of the luminescent material (20).

13. Domestic appliance device according to claim 12, characterized by a portion (18) associated with the temperature sensor (16) and by a control unit (24) for operating the light emitting diode (22) depending on a signal of a temperature sensor (16).

14. A method for producing a disc (10) from an at least partially transparent material for a household appliance device wherein the disc (10) comprises a user accessible front or top side (12), characterized in that in a portion (18) of the disc (10) below the front or top (12) of the disc (10) luminescent material (20) is introduced into the transparent material.

15. The method according to claim 14, characterized in that a powder with oxides of luminescent ions in the portion (18) on a back of the disc (10) is applied and then the portion (18) is locally heated with a laser to the luminescent ions diffuse into the transparent material.

16. The method according to claim 14, characterized in that recesses (26) are incorporated into the transparent material in the subregion (18) on a rear side of the disc (10) and the luminescent material (20) is introduced into the holes.

17. The method according to claim 16, characterized in that the recesses (26) after the introduction of the luminescent material (20) with a

Protective layer (28) are closed.

18. The method according to claim 16 or 17, characterized in that the recesses (26) are introduced with a laser in the back of the disc (10).