Patent Number: 
Section: description

FIG. 1 shows a first embodiment of the apparatus 1 for radiation treatment for personal care according to the invention, with a housing 2 in which a UV source 3 is present which in this embodiment comprises two compact UV lamps 33. The apparatus 1 further comprises a wall 4 manufactured from a light-transmitting material and closing off the housing 2. In this embodiment, the wall 4 is made from an inorganic glass, but the wall may alternatively be made from any other known type of UV-transmitting material. The wall 4 has a central area 7 and side areas 8 adjoining the central area, as viewed in longitudinal direction. The wall 4 has a lower transmission to radiation having a wavelength  less than 320 nm adjacent the central area 7 than adjacent the side areas 8. This is realized in this embodiment in that the wall has a greater thickness adjacent the central area than adjacent the side areas, as is apparent from FIG. 2a. It is advantageous if this greater thickness adjacent the central area is realized by means of a coating 21 on the wall, which coating is provided in a greater number of layers adjacent the central area 7 than adjacent the side areas 8. The coating in this embodiment comprises a sol-gel material, but the coating may alternatively comprise any other known type of material. The radiation originating from the UV source 3 is thus better transmitted adjacent the side areas 8 of the wall than adjacent the central area 7 of the wall 4. As a result, a distribution of effective radiation energy resulting from radiation with a wavelength  less than 320 nm over an irradiation plane 9 is realized as indicated with the curve UVBinv. in FIG. 2b. The value of the effective radiation energy is plotted on the vertical axis in FIG. 2b, and the longitudinal direction of the irradiation plane 9 is plotted on the horizontal axis. Compared with the curve UVBnorm, which indicates the distribution of effective radiation energy resulting from radiation with a wavelength  less than 320 nm in a known apparatus, it is apparent that the distribution realized over the longitudinal direction of the irradiation plane 9 by means of the apparatus according to the invention is substantially homogeneous. The problem of an uneven distribution of the effective radiation energy solved by the invention arises in particular in the longitudinal direction of the irradiation plane, which is why the distribution in lateral direction is not pictured here. It is furthermore visible in FIG. 2b that the distribution UVTotinv. of the total effective radiation energy resulting from radiation from the UV source with a wavelength  less than 320 nm and with a wavelength in the range from 320 to 400 nm taken together is also more homogeneous in an apparatus according to the invention than the corresponding distribution UVTotnorm realized in a known apparatus. FIG. 3a shows a second embodiment of an apparatus 1xe2x80x2 for radiation treatment for personal care according to the invention. In this embodiment, the wall 4xe2x80x2 is manufactured from a first material 10 with a comparatively high transmissivity to radiation having a wavelength  less than 320 nm, and a second material 11 is provided adjacent the central area having a comparatively low transmissivity to radiation with a wavelength  less than 320 nm. The first material in this embodiment comprises inorganic glass, but the first material may alternatively comprise some other known type of material with a comparatively high transmissivity to radiation with a wavelength  less than 320 nm. The second material in this embodiment comprises a sol-gel material, but the second material may alternatively comprise some other known types of material with a comparatively low transmissivity to radiation with a wavelength  less than 320 nm. The distribution of effective radiation energy over an irradiation plane in this embodiment approximates the distribution as pictured in the graph of FIG. 2b. It is furthermore advantageous if the material 11 has not only a comparatively low transmissivity to radiation with a wavelength  less than 320 nm but also a comparatively high transmissivity to radiation with a wavelength in the range from 320 to 400 nm. The UV source 3 produces a small quantity of radiation in this range, which quantity if transmitted fully by the wall 4xe2x80x2 will not be of any risk to the user. Since the second material 11 has a comparatively high transmissivity to radiation with a wavelength in the range from 320 to 400 nm, this radiation is transmitted for a major portion to the central portion of the irradiation plane 9. The comparatively small quantity of radiation produced by the UV source in this range is thus optimally utilized. FIG. 3b shows the wall 4xe2x80x2 viewed from a direction A in FIG. 3a. It is apparent here that the second material 11 is provided in a predetermined pattern of dots. It is noted that the shape of the material elements to be provided and the configuration in which this is done may be freely chosen in dependence on the desired embodiment of the apparatus for radiation treatment. It is also possible for the second material 11 to be provided on the wall 4xe2x80x2 in shapes other than in dots, and in configurations other than the pattern shown in FIG. 3b.  FIG. 4 shows a third embodiment of an apparatus 1xe2x80x3 for radiation treatment for personal care according to the invention, in which intermediate areas 5 are present between the central area 7xe2x80x3 and the side areas 8xe2x80x3, in which areas 5 the wall 4xe2x80x3 has a transmission to radiation with a wavelength  less than 320 nm which lies between the transmission of the central area 7xe2x80x3 and the transmission of the side areas 8xe2x80x3. In this embodiment, the wall 4xe2x80x3 comprises not only the coating 21, which is provided in a number of layers adjacent the central area as described with reference to FIG. 2a, but also further coating layers 31 provided adjacent to the intermediate areas 5 in a smaller number than the coating adjacent the central area. The wall 4xe2x80x3 thus has a transmission to radiation with a wavelength  less than 320 adjacent the intermediate areas 5 which lies between the transmission of the central area 7xe2x80x3 and that of the side areas 8xe2x80x3. The intermediate areas 5 thus contribute further to the realization of a substantially homogeneous distribution of effective radiation energy of radiation having a wavelength  less than 320 nm over the irradiation plane. It is noted that the transmission of the intermediate areas may be realized in alternative manners such as, for example, by means of a further material which is provided adjacent the intermediate areas in the embodiment as described with reference to FIG. 3a.  FIG. 5 shows a fourth embodiment of an apparatus 1xe2x80x2xe2x80x3 for radiation treatment for personal care according to the invention in which the housing 2 has a base wall 14 which extends substantially parallel to the UV-transmitting wall 4, which housing has at least one, in this embodiment two reflecting side walls 15 which extend from the base wall 14 but alongside the UV source 3 at an angle to said base wall. The reflecting side wall 15 comprises a material which has a comparatively low reflectivity for radiation with a wavelength  less than 320 nm at a side facing the UV source. In this embodiment, this material 16 comprises an aluminum alloy, but the material may alternatively comprise any other known type of material with a comparatively low reflectivity to radiation with a wavelength  less than 320 nm. This radiation is thus reflected towards the central portion of the irradiation plane to a low degree only. Furthermore, the wall 4xe2x80x2xe2x80x3 has a lower transmission to radiation with a wavelength  less than 320 nm adjacent the central area 7xe2x80x2xe2x80x3 than adjacent the side areas 8xe2x80x2xe2x80x3, which is realized in this embodiment in that the wall 4xe2x80x2xe2x80x3 has a coating of greater thickness adjacent the central area 7xe2x80x2xe2x80x3 than adjacent the side areas 8xe2x80x2xe2x80x3. It is noted that the lower transmission adjacent the central area 7xe2x80x2xe2x80x3 of the wall 4xe2x80x2xe2x80x3 may be realized in alternative ways, for example as described for the second embodiment of the apparatus according to the invention. The combination of the wall 4xe2x80x2xe2x80x3 with the reflecting side wall 15 comprising the material 16 of comparatively low reflectivity to radiation with a wavelength  less than 320 nm contributes to an even more homogeneous distribution of the effective radiation energy over the entire irradiation plane. It is advantageous here, furthermore, if said material 16 has a comparatively high reflectivity to radiation with a wavelength in the range from 320 to 400 nm, so that the radiation in this range is optimally utilized. It is noted that an apparatus for radiation treatment for personal care according to the invention also relates to types of such apparatuses other than the apparatus pictured in FIG. 1 such as, for example, a suntanning couch with a collapsible housing. It is further noted that besides the embodiments mentioned above alternative embodiments are equally possible, in which the wall adjacent the central area has a lower transmission to radiation with a wavelength  less than 320 nm than adjacent the side areas such as, for example, an embodiment in which the UV-transmitting wall is built up from materials with a varying transmissivity to radiation with a wavelength  less than 320 nm.