Radiation apparatus

A radiation apparatus for cosmetic, photobiological and/or photo chemical purposes containing at least one ultraviolet ray source and devices for operation for the production of the ignition voltage and operating current and a filter device for emitting rays in the region of 320 nm to 450 nm and for cutting out short wave rays below 320 nm and long wave rays above 800 nm and preferably above 450 nm.

BACKGROUND OF THE INVENTION 
This invention relates to a radiation apparatus for cosmetic, 
photobiological and/or photochemical purposes containing at least one 
ultraviolet ray source and devices for producing the ignition voltage and 
the operating current necessary for the operation and preferably including 
a filter apparatus. 
The radiation apparatus is to serve for the treatment of different 
diseases, for example, psoriasis, hyperbilirubinamie. Furthermore it is to 
be used for cosmetic purposes for direct tanning. 
Also it is used in the field of photo chemistry, for example, for drying of 
varnishes, for the hardening of plastic and for polymerization. 
At present it is known to use in the field of photobiology for medicinal as 
well as for cosmetic purposes, radiation apparatus with electric 
ultraviolet ray sources for treatment of different diseases (for example, 
psoriasis, hyperbilirubinamie) by ultraviolet radiations used in 
conjunction with medicines. In psoriasis treatment with ultraviolet 
fluorescent lamps, in which radiation strengths of about 60 W/m.sup.2 are 
used (with 365 nm), there is a psychological disadvantage to the patient 
because he must be practically shut up in a box. For cosmetic purposes 
especially in order to achieve the effect of secondary pigmentation 
(tanning after previous erythema) ultraviolet radiation with a wave length 
shorter than 320 nm is used. 
Furthermore it is known that in solaria light sources of the aforementioned 
type are used. 
As a rule for photochemical purposes, for the drying of varnishes, for the 
hardening of plastics and for polymerization mercury vapor high pressure 
lamps are used which emit mixed light in the region of about 250 nm up to, 
for the tube radiation, several 1000 nm. 
Instead of mercury, high or low pressure lamps, the latter for most part 
with fluorescence, and xenon high pressure lamps are used in such fields. 
The presently known radiation devices emit to a not inconsiderable extent 
conjunctivitis- and erythema-active rays, which in wrong dosages, can 
bring about considerable damage to health. This applies above all to 
ultraviolet ray sources which operate in the high pressure range. 
Radiation devices for photobiological purposes equipped with low pressure 
mercury vapor lamps (fluorescent lamps) are extremely expensive so that 
they can be used only in clinics and large practices and not for home 
treatment. 
The object of the invention is to provide a radiation apparatus for 
photobiological and photochemical purposes which supplies in the wave 
length region of 320-450 nm high radiation strengths and completely 
suppresses the radiation wave length shorter than 320 nm in order to avoid 
damage to health by conjunctivitis (inflammation of the conjunctiva) and 
erythema (sunburn). Furthermore radiation of longer wave length than 450 
nm should be substantially suppressed in order to avoid undesired effects 
on the radiation objects due to high energy loading. To be avoided in 
particular are dazzling, and damage to the skin by too high radiation 
loads, the latter particularly in the infra red range. 
This problem is solved according to the invention in that the short wave 
rays below 320 nm are completely suppressed. Discharge lamps which usually 
are used as ultraviolet ray sources emit the greatest part of their energy 
in the infra red range. Therefore the infra red rays as of about 800 nm 
are suppressed as far as possible. In order to reduce the radiation 
outside the effective range which is between 320 and about 450 nm it is 
desirable to filter out substantially all the longer wave rays above 450 
nm. 
An ultraviolet ray source of especially high intensity in the region of 
320-450 nm is the mercury vapor high pressure lamps especially those 
provided with iron iodide and gallium iodide. 
In order to obviate the devices connected in series usually necessary for 
the operation of the mercury vapor high pressure lamp, the lamp may be 
constructed as a mixed light lamp with the current limitation effected by 
an incandescent lamp winding. 
An ultraviolet ray source which operates as a high or maximum xenon 
pressure lamp can be intensified in the region of 320-450 nm if it is 
provided with a metal iodide, preferably iron iodide and gallium iodide. 
The short wave rays under 320 nm are suppressed by an ultraviolet edge 
filter. A very simple ultraviolet edge filter can be produced from plate 
glass and is usual in the art. 
If the temperatures are not too high polyesters also can be used as 
ultraviolet filters, either in the form of plates or foils. Applying 
polyester foil directly on the bulb or tube of the fluorescent lamp 
insures that no rays under 320 nm emerge. 
The radiation load in the visible range above 450 nm can be achieved by the 
use of color filters, preferably a blue violet filter. This filter may 
consist of glass, quartz or plastics in which finely divided heavy metal 
oxides, for example, cobalt, nickel, iron-oxide are dispersed or deposited 
on the surface. 
A color filter made from the violet glass may be placed over the burner of 
the high pressure lamp. It also serves as a protective tube for the 
sensitive burner quartz tube. If cobalt oxide is added to the fused 
quartz, the burner tube itself may serve as a blue violet filter whereby 
with suitable proportioning of the amount added, ultraviolet filtering in 
the region below 320 nm can be achieved. 
In the radiation procedure an infra red filter may be inserted between the 
ultraviolet ray source and the radiation object which may act either as an 
absorption or reflection filter. 
The simplest solution of this type is to use a heat absorptive glass, usual 
in the art, as an infra red filter. Instead of the maximum necessary three 
filter types, a single filter may fulfill the three functions if, for 
example, the corresponding additional materials for the color filtering 
and/or infra red filtering are added to the plate glass fusion in suitable 
quantities. The same applies if instead of the plate glass fusion a quartz 
fusion is used or the filter materials are finely divided in plastics or 
deposited on the surface. 
The housing in which the ultraviolet ray source is located is produced 
either from polished oxidized aluminum or it contains reflectors from this 
material in order to increase the radiation output. 
For cooling of the housing ventilation openings with shield plates are 
provided so that no unfiltered rays can emerge from the housing. The 
arrangement of these inlet and outlet openings is such that the ray 
source, the housing and the filters are sufficiently cooled. 
For increasing the cooling effect a ventilator is provided in order to 
carry out the cooling more effectively. 
The cooling of ultraviolet ray source and/or housing is suitably regulable 
or adjustable. This gives an optimum operating temperature for the housing 
and lamp. The housing must not be too hot because of the added devices and 
the danger of burns to operator of the radiation apparatus. 
The cooling may be effected by means of a ventilator and/or a blower, 
regulated or adjusted by electrical means. 
Advantageously the cooling is controlled so that the ultraviolet ray source 
is not cooled during ignition. Thus, an optimum operating temperature of 
the burner results; if the space between the burner and the protective 
tube upon starting the lamp is completely cooled, the optimum operating 
temperature of the burner is not obtained. 
The cooling is suitably regulated by an electronic delay switch which 
preferably also monitors the temperature of the ultraviolet ray source 
and/or housing. 
In order to obtain as high an ultraviolet ray output as possible the 
temperature at the wall of the burner must not fall short of a certain 
minimum value. On the other hand, it is important that at the place where 
the current leads to the electrode are embedded a maximum temperature must 
not be exceeded if the lamp is not to burn out prematurely. 
The exhaust cooling air may be discharged outside the room. 
Radiation devices of extremely high outputs containing several ultraviolet 
ray sources will heat up the room excessively if the exhaust air from 
cooling remains in the room. 
At least one additional ultra violet ray source which emits 
erythema-effective rays is included. It may be operated continuously or 
intermittently by impulse switching. 
Advantageously the ignition device is switched off after the ignition of 
the ultraviolet ray source. 
The ignition, which requires higher voltages than the usual line voltages, 
is effected either by resonance switchings, transformers or high frequency 
ignition devices which consist of spark sections and windings. After 
ignition with a high frequency device the full lamp current flows through 
the windings. Therefore the windings must be dimensioned correspondingly 
thick. If the ignition device is switched off after the ignition of the 
ultraviolet ray source considerable saving in cost, weight and space can 
be achieved. 
The current drawn by the radiation device is of such magnitude that current 
plugs used for normal domestic current circuits will suffice. Thus the 
radiation apparatus can be used as a home radiation apparatus. 
Also in order to be able to carry out home radiations it is necessary to 
design the electrical parts of the radiation apparatus so that they will 
operate on standard house voltage and current. This means that the 
lamp-burning voltage must amount to a maximum of 2/3 the line voltage of 
the power supply and must be properly fused so as not to exceed the 
maximum line current. On the other hand the highest possible output of the 
ultraviolet ray source (lamp) is necessary in order to achieve the best 
possible effect in the shortest time. 
The space between the burner bulb and protective tube may be cooled by air 
preferably supplied from the previously-described ventilator. The air 
cooling if necessary may be supplemented or replaced by suitably-arranged 
water cooling. Care must be taken that liquid coolant does not contact the 
burner, since a mercury vapor high pressure lamp for example operates at a 
temperature between 700.degree. and 900.degree. C. 
Special advantages of the radiation apparatus of the invention are: 
Avoiding of conjunctivitis and erythema by the filtering out of the rays 
below 320 nm, which rays according to the literature have a carcinogenic 
effect. 
By filtering out the infra red radiation the heat loading of the radiation 
object is considerably reduced so that even with very intensive radiation 
no heat erythema results. With a pigmenting effective radiation strength 
of about 150 W/m.sup.2, a total radiation loading of about 2500 W/m.sup.2 
would result if the infra red and visible-light portions are not filtered 
out. If these wave lengths are filtered out this value is reduced by about 
80%. 
Due to the blue violet filter the luminous density of the light source is 
reduced so markedly that any permanent dazzle phenomena is eliminated. 
The use of gallium iodide and iron iodide increases the radiation output of 
the high pressure discharge in the range of 320-450 nm by a considerable 
amount. If the mercury vapor high pressure lamp is constructed as a mixed 
light lamp the added device is dispensable and the lamp can be operated 
directly on standard power supply. 
Ultraviolet edge filters made from plate glass known in the art are 
extraordinarily cheap. The same applies to filters from polyesters. If a 
blue violet glass tube is used as the color filter, this results in a 
considerable reduction in cost compared with blue violet filter discs. 
One of the most important advantages however is that radiation wave lengths 
between 320 nm and 450 nm can now be achieved cheaply in practice. This 
applies to photobiology as well as also to photo chemistry.

In FIG. 1 the conjunctivitis sensitivity 1, the erythema sensitivity 2 and 
the spectral effect curve of the direct pigmentation 3 is shown in 
relative scale. 
The maximum for the sensitivity of the photo conjunctivitis is about 260 
nm; the dose threshold value corresponding to this wave length is about 
50Ws/m.sup.2. 
The maximum of the erythema sensitivity is about 297 nm; the dose threshold 
value with this wave length amounts to about 100,000 Ws/m.sup.2. 
FIG. 2 shows the spectral curve of the transmission values 4 of a filter 
device which consists of an ultraviolet edge filter (plate glass 5 nm), an 
infra red absorption filter (heat absorption glass 4 nm) and a color 
filter (blue violet glass 1 nm). In the range (not shown) from about 600 
nm to the far infra red the transmission value is about 6%. 
In FIG. 3 is shown the spectral ray output distribution of a 2000 W mercury 
vapor high pressure lamp with the filter device of FIG. 2 as a 
discontinuous curve 5 in relative scale. Each of the measurements were 
taken within a band width of 10 nm. 
FIG. 4 shows the spectral radiation output distribution of a 40 W 
fluorescent lamp with lead-activated barium disilicate, surrounded with a 
covering of 0.175 nm thick polyester foil as a curve 6 in relative scale. 
In FIG. 5 is shown one embodiment of a radiation apparatus with an 
ultraviolet ray source 7 surrounded with a protective glass tube 8 which 
serves as a filter. The space 9 between the burner tube 7 and protective 
tube 8 may be evacuated for thermal reasons. 
The inside of the housing 10 serves as a reflector. The heat absorption 
disc frame 11 and the residue ultraviolet absorber 12 are held together by 
the frame. The ventilator motor 14 with its ventilator vanes 15 draw the 
air through the inlet duct 16 and forces it past the lamp and through the 
surrounding space. The exhaust air escapes through the openings 17a and 
17b. The shield plates 18a and 18b prevent the escape of any unfiltered 
rays. The support frame 19 fixed preferably on both sides permits the lamp 
housing 10 to pivot over a predetermined range. The frame 19 is attached 
to the additional apparatus housing 20, the bottom plate 21 of which 
carries an ignition device 22 and the impedance coil 23. 
If a 2000 W mercury vapor lamp containing metal iodide is used as a ray 
source, a suitable color filter comprises a glass tube 40 mm in diameter 
and 1 mm wall thickness to reduce significantly the light density of the 
lamp. For reasons of cost the use of ultraviolet or blue glass discs is 
not recommended as the prices for these are so extremely high that the 
device may not be practical economically. 
As a heat protection filter it is proposed to use heat absorption glass 
usual in the art, which in the region of 800 nm (long infra red wave 
lengths) has a transmission value of only 6%. Possible residues of 
ultraviolet radiation, which is shorter than 320 nm, can be removed by 
ultraviolet edge filters which, similar to the blue violet glasses, are 
relatively expensive. The most effective solution economically is normal 
plate glass which likewise acts in this area as an edge filter. 
Such a radiation apparatus produces effective pigmentation radiation 
strengths in the order of magnitude of over 150 W/m.sup.2 (comparison 
value for unfiltered sun radiation with 90.degree. sun altitude is about 
50 W/m.sup.2). From this it follows that after a radiation exposure time 
of about ten minutes the threshold value for direct tanning is achieved 
(comparison value for the unfiltered sun radiation at 90.degree. sun 
altitude is about thirty minutes). The total radiation strength when the 
radiation apparatus is provided with a ventilator of ample size amounts to 
about 500 W/m.sup.2 (comparison value for unfiltered sun radiation at 
90.degree. sun altitude is about 1100 W/m.sup.2). 
The erythema threshold would be achieved purely mathematically after about 
seven hours, a value which cannot be checked experimentally (comparison 
value for the unfiltered sun radiation at 90.degree. sun altitude is about 
four minutes). By using appropriate dosages of methoxy psorales 
(preferably 0.75 to 1.5% 8-MOP solution or the corresponding internal 
application of this medicine), the threshold time for the direct tanning 
by sensitising of the skin can be reduced considerably. 
A similar sensitising may be effected by erythema-effective ultraviolet 
radiation, for example, by short time removal of the plate glass 12, this 
radiation being under the erythema threshold; or by additional ultraviolet 
ray sources which are operated continuously or upon impulse operation.