The present invention relates to illuminating instruments for diagnostics, surgery or therapy. The present invention more particularly relates to an illuminating dental

instrument for drilling, scaling, spraying or the like.

BACKGROUND ART OF THE INVENTION

A dental instrument for drilling, scaling or spraying generally needs an illumination for enabling the dentist to sufficiently clearly see the area being treated. Any sharp edges and color fringes in the illumination may lead to a fast fatigue of the dentist’s eye. Furthermore, the shadows of the tool i.e., the drill, the scaler and the air/water jet can make it difficult for the dentist to work. Therefore, it is generally desired that a relatively large area can be intensively and uniformly illuminated. Due to its luminous efficiency, white LED technology is generally used for the illumination in dental instruments. Most white LEDs are

manufactured as phosphor-conversion type LEDs which have a blue light emitting diode covered with yellow phosphor. The yellow phosphor emits white light upon excitation with the blue light. The LED technology is more efficient compared to incandescent lamps, however when used in environments where only a limited cooling is possible, the overheating leads to a reduction in the light output and the degradation of the LED.

DE10209194A1 discloses a handheld dental instrument for use with a detachable coupling device which has a light source for illuminating the object. This handheld dental instrument comprises an optical guide which is arranged to transmit the light from the light source to the body part. Th light source is an LED with integrated phosphor. The handheld dental instrument has a housing which supports the optical guide. The housing is detachably attachable to the coupling device.

US 2014/0134568 A1 discloses a medical/dental instrument having a lighting device which has an LED with integrated phosphor in the head portion.

US 2007/0121786 A1 discloses a diagnostic/treatment instrument such as a handpiece with a dental instrument tool and a light radiating unit which has an LED with integrated phosphor. DISCLOSURE OF THE INVENTION

An objective of the present invention is to overcome the disadvantages of the prior art and provide an illuminating instrument for diagnostics, surgery or therapy with an improved illumination.

This objective is achieved through the illuminating instrument for diagnostics, surgery or therapy as defined in claim 1. The subject-matters of the dependent claims relate to further developments.

The present invention provides an illuminating instrument for diagnostics, therapy or surgery of a body part. The illuminating instrument comprises at least one optical fiber for transmitting electromagnetic radiation from an electromagnetic radiation source to the body part; and a housing which supports the optical fiber. The optical axis of the optical fiber is circumferentially arranged in an illumination portion in the housing. The illumination portion is annular shaped and arranged to face the body part. The optical fiber in the illumination portion has one or more diffusing regions for diffusing the

electromagnetic radiation to the outside of the optical fiber through the circumferential surface. The illuminating instrument further comprises a conversion means, preferably phosphor which is supported by the housing without directly contacting the

electromagnetic radiation source and arranged between the diffusing regions and the body part for converting the electromagnetic radiation into visible light for illuminating the body part. The conversion means is outside the optical interface between the optical fiber and the electromagnetic radiation source.

A major advantageous effect of the present invention is that a relatively large area can be intensely and uniformly illuminated without any shadows by the diffusing regions through the circumferential surface of the optical fiber which is circumferentially arranged in the annular shaped illumination portion of the illuminating instrument. Another major advantageous effect of the present invention is that the electromagnetic radiation source is prevented from overheating as the conversion means is arranged away from the electromagnetic radiation source, namely on the light exit side which is exposed by the diffusing regions. Thereby, a temperature dependent color shift in the illumination can be prevented. Thereby also the radiation output of the electromagnetic radiation source can be generally increased, and the illumination efficiency can be improved. The life of the electromagnetic radiation source can be prolonged, and the need for maintenance can be obviated or reduced. Since the overheating is suppressed, the electromagnetic radiation source may be safely operated even at higher radiation output levels to attain a more intense illumination. Furthermore, due to the suppression of the overheating, the illuminating instrument can be more safely and comfortably held by the user during the applications. For instance, the user’s hand can be prevented from sweating.

According to an embodiment of the present invention, the illuminating instrument is preferably adapted for use with a coupling device which has an electromagnetic radiation source, for instance an LED or a laser diode without a conversion means such as phosphor or the like. The coupling device is preferably detachably attachable to the housing.

Alternatively, the coupling device may be an integral part of the illuminating instrument. The coupling device preferably has a hose including at least an electric wiring for connection to an electric power supply for powering the electromagnetic radiation source. In this embodiment, the coupling device and the illuminating instrument constitute an illuminating system. Alternatively, the coupling device may be battery driven. The battery may be exchangeable and/or rechargeable through a charging adapter. Alternatively, the hose of the coupling device may have another optical fiber for transmitting the

electromagnetic radiation to the illuminating instrument.

According to an embodiment of the present invention, the diffusing region preferably has a size and shape which matches the geometry of the area to be illuminated. The diffusing region preferably extends over the entire illumination portion. Alternatively, a plurality of identical diffusing regions are arranged at regular separations along the annular shaped illumination portion. Alternatively, the diffusing regions may be arranged at irregular separations along the annular shaped illumination portion.

According to an embodiment of the present invention, the optical fiber is preferably arranged into a groove which is formed into the surface of the housing. The groove is preferably provided in a size and shape that matches the optical fiber. The cross section of the groove is preferably parabolic to attain uniform illumination towards the body part. However, the groove may have various cross sections. For instance, the cross section is alternatively u-shaped. The depth of the groove is preferably slightly larger than the diameter of the optical fiber to provide space for filling a translucent sealing substance which has preferably a light diffusing characteristic. According to an embodiment of the present invention, the illumination portion preferably has a reflective surface to reflect the light towards the body part. The reflective surface is obtained by polishing the groove. Alternatively, the groove may be coated with a reflective substance. Alternatively, a separate annular shaped optical reflective surface is arranged into the groove behind the optical fiber.

According to an embodiment of the present invention, one or more lenses are preferably arranged between the diffusing regions and the body part respectively. The lens is preferably annular shaped. Thereby the size and shape of the illumination can be adjusted to the application.

According to alternative embodiments of the present invention, the illuminating instrument is preferably provided with a dental device such as dental spray device, a dental drill device, or a dental scaler device, or a camera for medical imaging. The camera may be sensitive to visible light, UV light or IR light. In these embodiments, the hose of the coupling device is preferably provided, in addition to the electric wiring, with supply lines for pressurized air and/or pressurized liquid. The dental spray device has nozzles for ejecting the pressurized air and the pressurized liquid. The dental drill device has a hub and a drill supported by the hub. The dental drill device is preferably driven by a turbine.

Alternatively, an electric motor may be used. The dental scaler device has a tip for scaling. The housing preferably has a grip portion and a head portion for supporting the respective dental device and/or the camera. The annular- shaped illumination portion is in the head portion around the camera, the nozzles, or the drill or the scaling tip to attain shadowless uniform illumination.

According to an embodiment of the present invention, the optical fiber preferably extends, inside the housing, from the grip portion to the illumination portion in the head portion.

According to an embodiment of the present invention, the diffusion region of the optical fiber preferably has at least a structure adapted to scatter the electromagnetic radiation to the outside. The structure includes voids and/or particles formed in the optical fiber. The structures are preferably formed into the core and/or the cladding of the optical fiber. The optical fiber in the illumination portion is provided without any protective coatings to enable the diffusion of the electromagnetic radiation through the circumferential surface.

According to alternative embodiments of the present invention, the electromagnetic radiation source is preferably adapted to user selectively emit blue light, violet light, or infrared light. The conversion means has a conversion material, preferably phosphor and/or lanthanide doped nanoparticles. The lanthanide doped nanoparticles convert near infrared light into near ultraviolet light which can be used for bioimaging. The conversion material is preferably coated onto the optical fiber at the respective diffusing region. Alternatively, the conversions material is arranged near the respective diffusing region. Different

diffusing regions may have different compositions of the conversion material for

illumination and/or medical imaging.

BRIEF DESCRIPTION OF THE DRAWINGS

In the subsequent description, the present invention will be described in more detail by using exemplary embodiments and by referring to the drawings, wherein

Fig. 1 - is a schematic perspective view of an illuminating system having the illuminating instrument and the coupling device according to an embodiment of the present invention;

Fig. 2A - is a schematic perspective view of the illuminating instrument in Fig. 1;

Fig. 2B - is a schematic perspective view of the coupling device in Fig. 1;

Fig. 3 - is a schematic bottom view of the head portion of the illuminating instrument in Fig. 1; Fig. 4A - is a schematic cross sectional view of the head portion of the illuminating instrument in Fig. 1, taken along the line A- A in Fig. 3;

Fig. 4B - is a schematic cross sectional view of the head portion of the illuminating instrument according to another embodiment, taken along the line A- A in Fig. 3;

Fig. 4C - is a schematic cross sectional view of the head portion of the illuminating instrument according to another embodiment, taken along the line A- A in Fig. 3;

Fig. 4D - is a schematic cross sectional view of the head portion of the illuminating instrument according to another embodiment, taken along the line A- A in Fig. 3;

Fig. 5 - is a schematic partial top view of the illuminating instrument showing the light distribution of the illumination.

The reference numbers shown in the drawings denote the elements as listed below and will be referred to in the subsequent description of the exemplary embodiments.

1. Illuminating instrument

2. Coupling device

3. E.M. Radiation source

4. Optical fiber 4a. Diffusing regions

4b. Circumferential surface

5. Housing

51. Grip portion

52. Head portion

52a. Illumination portion

52b. Groove

6. Conversion means

6a. Conversion material

7. Reflective surface

8. Dental drill device

8a. Hub

8b. Drill

9. Illuminating system

10. Hose

11. Lens

12. Diffusor

Fig. 1 shows an illuminating system (9) according to an embodiment of the present invention. As shown in Fig. 2A and Fig. 2B, the illuminating system (9) has an

illuminating instrument (1) and a coupling device (2). The illuminating instrument (1) is suitable for diagnostics, therapy or surgery of a body part. The illuminating instrument (1) is adapted for use with the coupling device (2). As shown in Fig. 2A and Fig. 2B, the illuminating instrument (1) and the coupling device (2) are detachably attachable. The housing (5) of the illuminating instrument (1) can be detachably attached to the coupling device (2). Alternatively, the coupling device (2) may fixed to the housing (5) so that it cannot be detached by the user. As shown in Fig. 2B, the coupling device (2) has an electromagnetic radiation source (3) for generating electromagnetic radiation. The electromagnetic radiation source (3) is preferably a LED without an integrated phosphor element that directly contacts the semiconductor. The coupling device (2) has a hose (10) for supplying electric power to the electromagnetic radiation source (3). As shown in Fig. 2A and Fig. 3, the housing (5) has a grip portion (51) and a head portion (52). As shown in Fig. 3, the head portion (52) has an illumination portion (52a). The illuminating instrument (1) has an optical fiber (4) for transmitting the electromagnetic radiation from the electromagnetic radiation source (3) to the illumination portion (52a) which faces the body part. As shown in Fig. 3, the optical fiber (4) is single -piece and has a light-output end and a light entrance end. Thereby the loss of illumination can be reduced as much as possible. The light-output end is in the head portion (52) and the light entrance end is in the grip portion (51). Alternatively, the optical fiber (4) may have exactly two pieces wherein one piece may have the light-output end which is in the head portion (52), and wherein the second piece may have the light entrance end which is in the grip portion (51). Thereby the assembly process can be simplified. These two-pieces can be connected during the assembly of the grip portion (51) and the head portion (52). The optical fiber (4) is supported by the housing (5) of the illuminating instrument (1). The optical fiber (4) extends, inside the housing (5), from the grip portion (51) to the illumination portion (52a) of the head portion (52). As shown in Fig. 3, the optical axis of the light-output end of the optical fiber (4) circumferentially extends in the illumination portion (52a) of the housing (5). The illumination portion (52a) is annular shaped and arranged to face the body part. Fig. 4A shows the cross section of the illumination portion (52a) of the illuminating instrument (1) in Fig. 1, taken along the line A-A in Fig. 3. The illumination portion (52a) has a groove (52b) on the surface of the housing (5). The optical axis of the light-output end of the optical fiber (4) is circumferentially arranged in the groove (52b). The groove (52b) matches the shape of the light output end of the optical fiber (4). As shown in Fig. 4A, the optical fiber (4) in the illumination portion (52a) has a diffusing region (4a) for diffusing the electromagnetic radiation to the outside of the optical fiber (4) through the circumferential surface (4b). The light-entrance end of the optical fiber (4) is directly connected/coupled with the electromagnetic radiation source (3). The diffusing region (4a) is annular shaped and extends over the complete illumination portion (52a). The illumination portion (52a) has a reflecting surface (7). The diffusion region (4a) of the optical fiber (4) has a structure adapted to scatter the electromagnetic radiation to the outside. The structure comprises voids and particles. The electromagnetic radiation source (3) is an LED which is adapted to emit blue light. The blue light emitting LED has no phosphor coating to prevent overheating inside the grip portion (51). Alternatively, an LED which emits violet light may be used. As shown in Fig. 4A, a conversion means (6) is supported by the housing (5) and arranged between the diffusing region (4a) and the body part for converting the electromagnetic radiation into visible light for illuminating the body part. As shown in Fig. 4A, the conversions means (6) has a conversion material (6a) that is directly arranged onto the respective diffusing region (4a). The conversion material (6a) includes phosphor. Fig. 4B to Fig. 4C show alternative versions of the embodiment. As shown in Fig. 4B and Fig. 4D, the conversion material (6a) is arranged as a thick layer on the respective diffusing region (4a). As shown in Fig. 4C, the conversion material (6a) is coated on the diffusing region (4a). As shown in 4C, an additional diffusor (12) is arranged between the diffusing region (4a) and the body part. As shown in 4D, a lens (11) is arranged between the diffusing region (4a) and the body part. The gaps in the groove (52b) are filled with a heat resistant transparent sealing material. As shown in Fig. 1, the illuminating instrument (1) has a dental drill device (8). The dental drill device (8) has a hub (8a) and a drill (8b) supported by the hub (8a). The head portion (52) supports the hub (8a). As shown in Fig. 3, the illumination portion (52a) is in the head portion (52) around the hub (8a). Alternatively, the illuminating instrument (1) may be provided with a dental spray device, a dental scaler device, and/or a camera. The camera may be detachably attachable to the outside of the housing (5) through a retainer on the housing (5). The retainer may be integrated or detachable as well. The camera is arranged to view the illuminated region underside head portion (52). From the acquired images the alignment / position of the illuminating instrument (1), specifically the dental drill, the scaler, the nozzle can be determined, and thus the user can be provided with a feedback for guidance based on the planned handling. The camera is preferably a 2D or 3D camera.