Preoperative lighting device

Abstract

A dental lighting device and process for using the same comprises at least one lighting system configured to light a predetermined dental zone with, over a first spectral range which is less than a reference wavelength between 405 nm and 475 nm, a first irradiance value E1 and, over a second spectral range greater than this reference wavelength, a second irradiance value E2, which lighting system is configured to function according to at least one first lighting mode in which the ratio of the first irradiance value E1 to the second irradiance value E2 is less than 12.

Claims

1. A dental lighting device, comprising at least one lighting system configured to light a predetermined dental zone with, over a first spectral range which is less than a reference wavelength, said reference wavelength being between 405 nm and 475 nm, a first average irradiance value E1 and, over a second spectral range greater than the reference wavelength, a second average irradiance value E2, and in which the lighting system is configured to function according to at least one first lighting mode, in which the ratio of the first average irradiance value E1 to the second average irradiance value E2 is less than 12, the lighting system being also configured to function according to at least one second lighting mode distinct from the first lighting mode, the dental lighting device comprising a switch configured to switch operation of the lighting system between the first lighting mode and the second lighting mode, and the switch being configured to switch operation of the lighting system between the first lighting mode and the second lighting mode by varying one of the two values of the first average irradiance value E1 and the second average irradiance value E2, whereas the other of these two values remains unchanged.

2. The device according to claim 1, in which the lighting system is configured, in the first lighting mode, to light the predetermined dental zone with the first average irradiance value E1 which is greater than 1 W/m.sup.2.

3. The device according to claim 1, in which, in the first lighting mode, said ratio is greater than 1.

4. The device according to claim 1, in which, in the first lighting mode, said ratio is less than 10.

5. The device according to claim 1, in which the reference wavelength is between 440 nm and 460 nm.

6. The device according to claim 1, in which the first spectral range is between 370 nm and the reference wavelength.

7. The device according to claim 1, in which the second spectral range is between the reference wavelength and 780 nm.

8. The device according to claim 1, comprising an operating light, and in which the lighting system comprises at least one ambient light source connected to the operating light.

9. The device according to claim 1, comprising a supplementary instrument, and in which the lighting system comprises at least one supplementary light source connected to the supplementary instrument.

10. The device according to claim 9, in which the supplementary instrument comprises a body having a fixing part capable of cooperating with a tool to fix said tool and the body relative to each other, and at least one housing arranged in the region of the fixing part and in which said at least one supplementary light source is mounted.

11. The device according to claim 9, in which the lighting system comprises a plurality of discrete supplementary light sources.

12. The device according to claim 11, in which the lighting system comprises at least two supplementary light sources having separate emission spectra.

13. The device according to claim 11, in which the lighting system comprises a luminous flux mixer at the input of which luminous fluxes respectively emitted by the supplementary light sources are injected, and at the output of which a light beam (F) adapted to contribute in all or part to lighting the predetermined dental zone emerges, with the first average irradiance value E1 and the second average irradiance value E2.

14. The device according to claim 9, in which the supplementary light source comprises a light-emitting diode.

15. The device according to claim 1, in which the lighting system is configured so that the ratio of the first average irradiance value E1 to the second average irradiance value E2 has different values in the first lighting mode and in the second lighting mode respectively.

16. A process for lighting configuration using a dental lighting device, the dental lighting device comprising at least one lighting system configured to light a predetermined dental zone with, over a first spectral range which is less than a reference wavelength, said reference wavelength being between 405 nm and 475 nm, a first average irradiance value E1 and, over a second spectral range greater than the reference wavelength, a second average irradiance value E2, and in which the lighting system is configured to function according to at least one first lighting mode, in which the ratio of the first average irradiance value E1 to the second average irradiance value E2 is less than 12, the lighting system being also configured to function according to at least one second lighting mode distinct from the first lighting mode, the dental lighting device comprising a switch configured to switch operation of the lighting system between the first lighting mode and the second lighting mode, and the switch being configured to switch operation of the lighting system between the first lighting mode and the second lighting mode by varying one of the two values of the first average irradiance value E1 and the second average irradiance value E2, whereas the other of these two values remains unchanged, wherein the process comprises a configuration step of the lighting system, during which the lighting system is configured so that the latter operates according to the at least one first lighting mode, in which said lighting system lights the predetermined dental zone with, over the first spectral range which is less than the reference wavelength between 405 nm and 475 nm, the first average irradiance value E1 and, over the second spectral range greater than the reference wavelength, the second average irradiance value E2, and in which the ratio of the first average irradiance value E1 to the second average irradiance value E2 is less than 12, wherein the lighting system is configured by varying at least one of the first average irradiance value and the second average irradiance value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The attached drawings are schematic and are not to scale; their chief aim is to illustrate the principles mentioned in the present explanation. In these attached drawings:

(2) FIGS. 1A, 1B and 1C show respectively a partial sectional view, a frontal view and a sectional view IC-IC of a first embodiment of a dental lighting device according to the present explanation;

(3) FIG. 2 shows the emission spectrum of a light-emitting diode of a first category used in this first example;

(4) FIGS. 3A and 3B show different choices of emission spectra for a light-emitting diode of second category used in this first example;

(5) FIG. 4 schematically shows the evolution of the ratios of values of the control signals of the abovementioned diodes as a function of the selected lighting mode with a second embodiment of a dental lighting device according to the present explanation;

(6) FIGS. 5A, 5B, 5C and 5D show contrast evolutions between portions of bared enamel and portions of scaled enamel, obtained with the device according to the abovementioned second example, as a function of the selected lighting mode;

(7) FIG. 6A schematically shows the lighting of a predetermined dental zone by the device according to the abovementioned first or second embodiment;

(8) FIG. 6B schematically shows the lighting of a predetermined dental zone by a dental lighting device according to a third embodiment according to the present explanation;

(9) FIG. 7 is a graphic schematically illustrating an example of determination of the first irradiance value E1 and of the second irradiance value E2 according to any one of the abovementioned three embodiments.

DETAILED DESCRIPTION OF EMBODIMENTS

First Embodiment

(10) As illustrated in FIG. 6A, a dental lighting device according to this first example comprises a lighting system configured to light a predetermined dental zone 50.

(11) Within the scope of the present explanation, the expression a predetermined dental zone designates a surface located in an imaginary plane whereof the characteristic dimensions are of the order of magnitude of those of the anatomical part which is usually observed by a practitioner during a dentistry procedure.

(12) For example, this surface can exhibit characteristic dimensions between 0.5 centimeters and 5 centimeters, for example between 1 centimeter and 3 centimeters.

(13) FIG. 6A arbitrarily and non-limiting illustrates this surface by way of a disc the diameter of which is equal to a characteristic dimension of the type of those previously described. Without departing from the scope of the present explanation, any other form could be provided for this surface (for example a rectangle or a square whereof the sides are equal to the dimensions characteristic of the type of those previously described), provided only that its characteristic dimensions were of the abovementioned order of magnitude.

(14) According to this example, the dental lighting device comprises a supplementary instrument 1, seen better in FIGS. 1A to 1C, and the lighting system comprises at least one supplementary light source connected to this instrument 1.

(15) According to this example, the lighting system of this instrument 1 is configured to emit a first luminous flux F which, after propagation, lights the dental zone 50.

(16) In particular, as illustrated in FIG. 7, the lighting system of this instrument 1 is configured to light the dental zone 50, over a first spectral range which is less than a reference wavelength between 405 nm and 475 nm, with a first irradiance value E1 and, over a second spectral range greater than this reference wavelength, a second irradiance value E2.

(17) As already indicated above, in this document, irradiance value or more precisely average irradiance value should be understood as the conventional radiometric definition of this term, that is to say, in the present circumstances, the average light power received per unit of area, and this value is calculated by integrating over the entire spectral range under consideration (i.e. the first or second spectral range within the context of the invention).

(18) More particularly, according to this example the reference wavelength is selected equal to 470 nm; the first spectral range is between a lower limit, equal to 370 nm, and this reference wavelength at 470 nm; and the second spectral range is between this reference wavelength at 470 nm and an upper limit, equal to 750 nm.

(19) Also, according to this example the lighting system is configured to emit a first plurality of light beams, with a first continuous spectrum, which is also over the entire extent of the first spectral range. Accordingly, each light beam belonging to this first plurality is emitted by the lighting system at a wavelength included in the first spectral range, in particular between 370 nm and 470 nm.

(20) Without departing from the scope of the present explanation, it could be provided however that the lighting system is configured to emit this first plurality of light beams with a discontinuous spectrum and/or one not spreading over the entire extent of the first spectral range (emitting for example one or more bands or stripes spaced apart from each other, each of these bands or stripes having a central wavelength included in the first spectral range).

(21) Also, after propagation, the light beams of the first plurality emitted in this way light up the dental zone 50 with a first irradiance value E1.

(22) According to this example, this first irradiance value E1 is calculated as follows: for each wavelength L1 belonging to the first spectral range, the elementary irradiance dE1(L1) as is calculated follows: for each point of coordinates (x, y) belonging to the surface S defining the dental zone 50, the elementary irradiance d.sup.2E1(x, y, L1) is calculated; the average value of this elementary irradiance d.sup.2E1(x, y, L1) over the entire surface S is calculated to determine dE1(L1); the average value of this elementary irradiance dE1 (L1) over the entire first spectral range is calculated to determine the value E1.

(23) The first average irradiance value E1 is thereby obtained. This value E1 is equivalent to the average light power received per unit of area and is calculated by integrating over the entire first spectral range.

(24) In addition, according to this example, the lighting system is configured to emit a second plurality of light beams, with a second continuous spectrum, which is also over the entire extent of the second spectral range. Accordingly, each light beam which belongs to this second plurality is emitted by the lighting system at a wavelength which is included in the second spectral range, in particular between 470 nm and 750 nm.

(25) Without departing from the scope of the present explanation, it could however be provided that the lighting system is configured to emit this second plurality of light beams with a discontinuous spectrum and/or one not spreading over the entire extent of the second spectral range (emitting for example one or more bands or stripes spaced apart from each other, each of these bands or stripes having a central wavelength included in the second spectral range).

(26) Also, after propagation, the light beams of the second plurality emitted in this way together light up the dental zone 50 with a second irradiance value E2.

(27) According to this example, this second irradiance value E2 is calculated as follows: for each wavelength L2 belonging to the second spectral range the elementary irradiance dE2(L2) is calculated as follows: for each point of coordinates (x, y) belonging to the surface S defining the dental zone 50, the elementary irradiance d.sup.2E2(x, y, L2) is calculated; the average value of this elementary irradiance d.sup.2E2 (x, y, L2) over the entire surface S is calculated to determine dE2(L2); the average value of this elementary irradiance dE2(L2) over the entire second spectral range is calculated to determine the value E2.

(28) The second average irradiance value E2 is thereby obtained. This value E2 is equivalent to the average light power received per unit of area and is calculated by integrating over the entire second spectral range.

(29) According to this example, the lighting system is configured to function only according to a first and single lighting mode in which the ratio of the first irradiance value E1 to the second irradiance value E2 is less than a predetermined threshold value.

(30) In this example, this ratio E1/E2 in this first lighting mode is selected equal to around 8 (eight).

(31) The supplementary instrument 1 which comprises this lighting system will now be described in greater detail by means of FIGS. 1A to 1C.

(32) According to this example, this supplementary instrument comprises a body having a fixing part 11 capable of cooperating with a tool (not shown, this tool can for example be a conventional scaling tool) to fix said tool and the body relative to each other.

(33) According to this example, the fixing part 11 corresponds to an end part of the body 1, and has dimensions adapted to allow this end part to be introduced into the mouth of a patient to perform a dentistry procedure by way of the tool to be fixed on said body 1.

(34) Also, the lighting system comprises a plurality of supplementary light sources, separate from each other.

(35) According to this example, the lighting system comprises a first group comprising one or more supplementary light sources, each of which has one and the same identical first emission spectrum (better seen in FIG. 2); and at least one second group comprising one or more other supplementary light sources, each of which has one and the same second emission spectrum, different to the first emission spectrum (clearer in FIGS. 3A and 3B, which have different variants of this second spectrum).

(36) In particular, in this example the abovementioned first group comprises four supplementary light sources, whereas the abovementioned second group comprises two supplementary light sources. Accordingly, in this example the lighting system comprises a total of six supplementary light sources.

(37) More particularly, each of these six supplementary light sources comprises a light-emitting diode. Accordingly, in this example, the abovementioned first group comprises four light-emitting diodes 12F, each of which presents the abovementioned first emission spectrum. Put otherwise, the abovementioned second group comprises two light-emitting diodes 12B, each of which presents the abovementioned second emission spectrum.

(38) Also, according to this example, the supplementary instrument has a plurality of housings, in which the plurality of supplementary light sources 12F, 12B is respectively mounted. In this example, these housings are arranged angularly at substantially regular intervals (see FIG. 1C), in the region of the fixing part 11, in particular slightly back from the end from which the tool is intended to project from the body 1.

(39) In addition, according to this example the lighting system comprises a luminous flux mixer, in particular a light guide 13, at the input of which luminous fluxes respectively emitted by each of the diodes 12F, 12B are injected, and at the output 13A of which a light beam F emerges (better seen in FIG. 6A) adapted, as such, to enable lighting of the dental zone 50 with the planned first and second irradiance values E1 and E2.

(40) In particular, this light guide 13, seen front on in FIG. 1B, is shaped, at least at output, into a light crown 13A. It guides light from the diodes 12F, 12B to the end of the body 1 from which the tool is designed to project.

(41) Also, FIG. 2 illustrates the first emission spectrum of each of the diodes 12F of the abovementioned first group.

(42) According to this example, this first spectrum comprises a single width peak at mid-height around 20 nm and centred on a wavelength around 450 nm. Accordingly, each diode 12F of the first group emits light beams only in the first spectral range defined in FIG. 7.

(43) Therefore, each diode 12F participates only in forming at least part of the lighting in blue of the dental zone 50 for the purpose of producing the first irradiance value E1. Inversely, these diodes 12F make no contribution to producing lighting in a colour warmer than blue of this zone 50 with the second irradiance value E2.

(44) Also, FIG. 3A illustrates a first variant S1 of the second emission spectrum of each of the diodes 12B of the abovementioned second group.

(45) In particular, this second spectrum according to this first variant comprises a first peak of greater intensity, and a second peak of lesser intensity.

(46) More particularly, this first peak is centred on a first wavelength smaller than a second wavelength on which the abovementioned second peak is centred. Especially, these first and second wavelengths are respectively equal to around 455 nm and around 560 nm.

(47) In addition, this first peak has a width at mid-height smaller than that of the second peak (especially around 20 nm as opposed to around 120 nm).

(48) Therefore, each diode 12B participates actively not only in forming at least part of the lighting in blue of the dental zone 50 for the purpose of producing the first irradiance value E1, but also participates actively in forming at least part of the lighting in a colour warmer than blue of this zone 50 for the purpose of producing the second irradiance value E2.

(49) Also, the colour temperature associated with this second emission spectrum according to this first variant S1 is around 6500 K.

(50) In addition, in addition to the abovementioned first variant S1, FIG. 3B illustrates second and third variants S2 and S3 of the second emission spectrum of the diodes 12B of the second group.

(51) These second and third variants S2 and S3 are similar to the first variant S1, such that their description will not be repeated in detail. They do have however the few differences mentioned hereinbelow.

(52) The second variant S2, and even more the third variant S3, contribute more to producing the second irradiance value E2, their second respective peaks being more pronounced than the second peak of the first variant S1.

(53) Also, the third variant S3 participates substantially less in producing the first irradiance value E1, its first peak being lessened relative to the first respective peaks of the first variant S1 and of the second variant S2, substantially equal.

(54) Finally, the colour temperature associated with the second variant S2 is around 4500K, whereas that associated with the third variant S3 is around 3000 K.

(55) Also, according to this example the dental lighting device comprises a control system (not shown) coupled to the lighting system and configured to control operation of said lighting system according to the abovementioned first lighting mode.

(56) In particular, the control system is configured to generate a plurality of control signals which are respectively transmitted to the plurality of diodes 12B, 12F of the lighting system to control their light emission.

(57) Especially, in this single first lighting mode these control signals adopt respective first signal values which are adapted to let the lighting system light up the dental zone 50 with the ratio E1/E2 equal, in this example, around 8 as previously indicated.

Second Embodiment

(58) By way of FIGS. 4 to 5D, a dental lighting device according to a second embodiment according to the present explanation will now be described.

(59) A dental lighting device according to this second embodiment differs from the dental lighting device according to the first embodiment previously described, only in that the lighting system of the dental lighting device according to this second example is configured to function according to not only the first lighting mode described in association with the first example, but also according to at least one second lighting mode distinct from this first mode. In fact, as indicated during the description of the first embodiment, the lighting system of the dental lighting device according to this first example is configured to function according to the first lighting mode only.

(60) In particular, according to this second example, the lighting system is configured to function according to any mode of: the first lighting mode previously described in association with the first example. This first lighting mode produces a first value R1 for the ratio E1/E2; a second lighting mode, distinct from this first mode, which produces a second value R2 pour the ratio E1/E2 which is less than R1; and a third lighting mode, distinct from this first mode and this second mode, which produces a third value R3 for the ratio E1/E2 which is less than R2;

(61) It should be noted that alternative to this second example, the lighting system could be configured to switch only between the first and second lighting modes as mentioned above.

(62) According to this second example, moving from one lighting mode to another is done by means of a switch (not shown) which is configured to switch operation of the lighting system from one mode to another.

(63) In particular, the switch of a device according to this second example is coupled to the control system (which is described in more detail in association with the abovementioned first embodiment), and is configured to switch the control system from one lighting mode to another.

(64) Also, the switch is configured to cause variations in the respective values of all or some of the control signals generated by the control system, so as to vary the ratio E1/E2 between the abovementioned three values R1, R2 and R3 from one lighting mode to another.

(65) In particular, as illustrated in FIG. 4, in the first lighting mode the control signals respectively associated with the diodes 12B of the second group of diodes each adopt a value N1, whereas the control signals respectively associated with the diodes 12F of the first group of diodes each adopt a value N4.

(66) In addition, in the second lighting mode the control signals respectively associated with the diodes 12B of the second group of diodes each adopt a value N2 greater than N1, whereas the control signals respectively associated with the diodes 12F of the first group of diodes each adopt the abovementioned value N4.

(67) Finally, in the third lighting mode the control signals respectively associated with the diodes 12B of the second group of diodes each adopt a value N3 greater than N2, whereas the control signals respectively associated with the diodes 12F of the first group of diodes each adopt the abovementioned value N4.

(68) Therefore, the fact that the value N3 is greater than the value N2, which in turn is greater than N1, whereas the value N4 remains unchanged for the three lighting modes, means that the first value R1 is greater than the second value R2 which in turn is greater than the third value R3.

(69) Also, in this example, the control signals respectively associated with the diodes 12F of the first group of diodes can be binary signals (all or nothing), since it is not necessary for them to generate other non-zero values than the abovementioned value N4.

(70) From another perspective, in this example the control signals respectively associated with the diodes 12B of the second group of diodes can be analog or digital signals adapted to sequentially generate at least the abovementioned three non-zero values N1, N2 and N3.

(71) By way of illustrative and non-limiting example, R1 is selected arbitrarily equal to 8, R2 equal to 5 and R3 equal to 1.5. This shows the contrasts illustrated in FIGS. 5A to 5D described hereinbelow. As indicated above, optimal observation conditions are obtained when the ratio between the ratios E1/E2 for each switching operation of lighting mode is between 2 and 20 (limits included) or, where appropriate, between 0.05 and 0.5 (limits included).

(72) In particular, FIG. 5A shows the perception which a practitioner can have of a first tooth, whereof the enamel is slightly porous, when this tooth is lit under the first lighting mode, with the first value R1. In this case, the contrast between scaled portions of the tooth and portions of the tooth devoid of tartar is good since the developing substance does not easily penetrate these portions devoid of tartar, such that the flux reflected specularly by these portions devoid of tartar is preponderant over the fluxes that they emit no fluorescence from the developing substance, and even if the tooth is lit with a second irradiance value E2 which is weak relative to the first irradiance value E1. Therefore, the first lighting mode can be qualified as a mode adapted for observation of the tartar for slightly porous enamel.

(73) Also, FIG. 5B shows the perception which a practitioner can have of a second tooth, whereof the enamel is more porous than that of the abovementioned first tooth when this second tooth is lit also under the first lighting mode with the first value R1. In this case, the contrast between scaled portions of the tooth and portions of the tooth devoid of tartar is mediocre since the developing substance can easily penetrate these portions devoid of tartar. It eventuates that the second irradiance value E2 this time is insufficient relative to the first irradiance value E1 to let the flux reflected specularly by the surface of the enamel of these portions devoid of tartar be substantially greater than the flux emitted by fluorescence from the porous interior of these portions. The practitioner then perceives a yellowish colour for the whole of the tooth.

(74) To rectify this problem, this second tooth can be observed under the second lighting mode, in which the flux reflected specularly is augmented relative to the flux emitted by fluorescence, due to the fact that the second value R2 of the ratio E1/E2 is less than the first value R1, without as such masking the lighting in blue which results from the first irradiance value E1. Therefore, the practitioner can observe this second tooth with the contrast illustrated in FIG. 5C. The second lighting mode can be qualified as a mode adapted for observation of tartar for substantially porous enamel.

(75) Finally, FIG. 5D shows the perception which a practitioner can have of the first tooth or of the abovementioned second tooth, when they are lit under the third lighting mode. In this third mode, the flux reflected specularly is still more augmented relative to the flux emitted by fluorescence, due to the fact that the third value R3 of the ratio E1/E2 is less than the second value R2. But this time the second irradiance value E2 is too much relative to the first irradiance value E1 such that the lighting in the colour warmer than blue substantially masks the lighting in blue. It eventuates that in this third lighting mode contrast is poor, and only the anatomical structure of the tooth can be observed by the practitioner due to the specular reflections from the surface of the enamel which he sees. The third lighting mode can be qualified as a mode adapted for observation of the tooth without revealing the tartar.

(76) It is pointed out that all other characteristics described in association with the first embodiment, which have not been described again in association with the second embodiment for streamlining the size of the present explanation, can evidently be repeated, by choice, alone or in combination, by this second embodiment.

Third Embodiment

(77) FIG. 6B illustrates a dental lighting device according to a third embodiment according to the present explanation.

(78) A dental lighting device according to this third embodiment differs from the dental lighting devices according to the first and second embodiments previously described, only in that the lighting system of the dental lighting device according to the third example comprises not only a supplementary instrument 1, which integrates a plurality of supplementary light sources configured to light the surface of the dental zone 50 with a first luminous flux F, but also an operating light 100, which integrates at least one ambient light source configured to light the surface of the dental zone 50 with a second flux F.

(79) Accordingly, in this third example the ambient light source of the operating light can participate actively in obtaining the preferred value of the ratio E1/E2, whereas in the first and second embodiments the supplementary light sources enabled them to produce said preferred value of the ratio E1/E2 alone.

(80) It indicates that all the other characteristics described in association with the first embodiment or the second embodiment, which have not been described again in association with the third embodiment to streamline the size of the present explanation, can evidently be reprises, by choice, alone or in combination, by this third embodiment.

(81) In addition, it should be noted that the modes or embodiments described in the present explanation are given by way of illustration and non-limiting, where in terms of this explanation an expert can easily modify these modes or embodiments or envisage others within the scope of the invention.

(82) Also, the different characteristics of these modes or embodiments can be used alone or can be combined. When they are combined, these characteristics can be as described hereinabove or different, as the invention is not limited to the specific combinations described in the present explanation. In particular, a characteristic described in relation to a mode or embodiment can be applied similarly to another mode or embodiment, unless specified otherwise.