Dental treatment lighting equipment

Abstract

A medical lighting device (100), particularly a dental treatment lighting device for illuminating the oral cavity of a surgical field, comprises a light source (50) having at least one LED light source (52) arranged on a circuit board (51), and a cup-shaped housing (10) for housing the light source (50), the housing comprising a light-emitting aperture (18) for emitting light. The housing has a bottom region (11) for supporting the circuit board (51) in surface contact, and a wall region (13) that extends circumferentially from the bottom region (11) to the light-emitting aperture. The housing (10) is composed of a plastic outer shell (20) and a metal inner shell (30) in contact with the inside of the outer shell (20), and the circuit board (51) is in thermal surface contact with the inner shell (30) that extends beyond the bottom region (11) into the wall region (13).

Description

Technical Field

[0001] The present invention relates to a medical lighting device (Note: In the original text, it is "Medizinische Leuchte", which is often referred to as "shadowless lamp" in Japan), and particularly to a dental treatment lighting device for illuminating the oral cavity in the surgical field.

Background Art

[0002] In order to ensure optimal medical treatment, it is essential to appropriately illuminate the treatment site during surgery, dental treatment, or examination. In order to optimize the lighting while protecting the patient, various basic conditions need to be considered. These are reflected in various standards. For example, the shape of the irradiation field, a predetermined minimum value of the color rendering index of the lighting, and a minimum value of the illuminance are defined.

[0003] A lighting device that meets these requirements is known, for example, from Patent Document 1 by the applicant. This document describes a dental lighting device that realizes desired lighting using five independent lighting units each provided with an LED light source and a corresponding optical system. These five lighting units are spatially dispersed and integrated within the light housing. The plurality of LED light sources are arranged on a common support and aligned so that an overlapping projection is surely performed on one object surface. Thereby, shadowless lighting in the surgical field is realized. The lighting is as uniform as possible and is maintained even when the light of an individual lighting unit is blocked (for example, by a doctor). The plurality of lighting units are arranged on a common support as described above. The support surely performs appropriate alignment between the lighting units and is thermally coupled to the light housing. Thereby, a relatively uniform heat distribution is obtained in the light housing. This is advantageous because it is essential to realize a uniform and not overly high surface temperature in order to avoid irritation during the use of the lighting device or medical equipment in general.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] European Patent Application Publication No. 2 469 158 (A2) [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In prior art lighting devices, precise alignment of multiple lighting units is essential to achieve optimal lighting effects. This alignment is relatively time-consuming. Therefore, in principle, it is advantageous to concentrate light generation on a smaller area. In this case, light can be controlled or adjusted more easily and efficiently, and equivalent or better lighting quality can be achieved with less effort.

[0006] However, concentrating light generation in a small area leads to a problem where localized heat generation increases compared to the dispersed light source arrangement in prior art, raising the risk of so-called hot spots forming in the light housing. Such hot spots not only increase the risk of damage to electronic components but also pose a danger to patients or doctors.

[0007] Therefore, the present invention is based on the objective of providing a medical, particularly dental, therapeutic lighting device configured to dissipate the heat generated during operation as uniformly as possible through the housing. [Means for solving the problem]

[0008] This problem is solved by a lighting device having the features of claim 1. Advantageous further developments of the present invention are the subject of the dependent claims.

[0009] The solution according to the present invention is based on a special configuration of a light housing that houses the light source, and is configured to dissipate the heat generated within the housing very efficiently and dissipate it to the surroundings over a wide area. As a result, the concept of the present invention is particularly suitable for lighting devices that use a small number of light sources concentrated in a small area. However, the solution according to the present invention is also applicable when the light sources are distributed over a wider area.

[0010] According to the present invention, a cup-shaped (topfartig) light housing having at least one LED substrate positioned at its bottom has a multilayer structure. In particular, the housing is composed of a plastic outer shell and a metal inner shell in contact with the inside of the outer shell, the LED substrate is in surface contact with the inner shell in a heat-transferable manner (flachigem Warmekontakt), and the inner shell extends beyond the bottom region of the housing into the wall region.

[0011] According to the present invention, a medical lighting device, in particular a dental treatment lighting device intended for illuminating the oral cavity in the surgical field, is proposed. This lighting device is A light source having at least one LED light source arranged on a circuit board, • A cup-shaped housing that contains a light source and forms an opening for emitting light, The housing comprises a bottom region for supporting the circuit board in surface contact (flachigen Lagerung in the original text) and a wall region that extends circumferentially (umlaufend in the original text) from the bottom region to the light-emitting aperture. According to the present invention, the housing is composed of a plastic outer shell and a metal inner shell in contact with the inside of the outer shell, the circuit board is in thermal contact with the inner shell in a surface contact manner (flachiger Warmekontakt in the original text) that allows heat to be transferred, and the inner shell extends beyond the bottom region into the wall region.

[0012] This two-layer or double-layer structure of the light housing has been found to provide an extremely efficient method of uniformly dispersing heat generated from the light source, ultimately radiating it uniformly to the surrounding environment through almost the entire outer surface of the housing. In particular, the heat dissipation achieved here is so efficient that even when operating at maximum output for extended periods, temperatures on the housing surface do not become uncomfortable for patients, doctors, or users of the lighting in general. At the same time, reliable heat dissipation, which is essential for the operation of the lighting device, is ensured. This is remarkable considering that the outer surface of the light housing according to the present invention is made of plastic, a material that does not inherently possess good thermal conductivity. However, by utilizing the inner shell according to the present invention, this inherently unfavorable characteristic of the outer shell does not manifest. Therefore, the outer surface of the light housing can be formed solely from plastic, an electrically insulating material, which offers advantages in terms of the operability and safety of the lighting device. Furthermore, compared to a simple heat sink, such as a metal block that absorbs heat from an LED light source, the concept according to the present invention differs in that the inner shell is an actual functional component of the light housing and can also perform additional housing functions, as will be described in more detail below.

[0013] The outer shell may be configured to protrude beyond the inner shell in the wall region of the housing and extend to the light-emitting aperture. In particular, the outer shell may have mounting means (Befestigungsmittel in the original text) in the wall region facing the light-emitting aperture. The mounting means is for holding a light-transmitting cover that closes the light-emitting aperture and / or optical elements that affect the light emitted from the light source.

[0014] The outer shell, or plastic portion of the light housing, may constitute one or more gripping elements, which allow the lighting device to be moved or aligned to a predetermined position. In this case as well, it is advantageous that these parts of the housing are made of plastic, which is an electrically insulating material.

[0015] On the other hand, the inner shell preferably has structural elements in its bottom region for positioning the circuit board in place. These structural elements particularly constitute pins (stifte) or bridges (stages) that penetrate centering openings formed in the circuit board. This ensures the precise placement of the light source. This is advantageous because it also allows for proper placement of the light source relative to other optical elements. This makes it possible to appropriately control the light to illuminate the processing area uniformly and homogeneously. Particularly preferably, the circuit board has two centering openings, one of which has a cross-section that conforms to the outer shape of the pin or bridge, and the other centering opening is composed of an elongated hole that allows relative displacement between the circuit board and the inner shell. This prevents the generation of stress due to differences in thermal expansion. Next, the circuit board can be attached to the inner shell using a frame-shaped clamping element. This clamping element elastically presses the circuit board against the inner shell. In particular, the clamping element is attached to the inner shell via a screw holding portion (Schraubhalterung), and preferably, the structural element may constitute a screw passage (Schraubkanale) for attaching the clamping element.

[0016] The LED light source is preferably located in the center of the circuit board and occupies only about 1% of the circuit board's surface area. Particularly preferably, the LED light source consists of two circuits, each of which is a series circuit of multiple (especially three) LEDs.

[0017] By providing so-called thermal pads (or "warmeleitpads") on the back of the circuit board opposite the LED light source, heat transfer from the LED light source to the inner shell of the light housing can be further improved. These pads extend radially or fan-shaped from the center of the circuit board outward, covering at least 80% of the circuit board's area. These thermal pads form electrically insulated regions from one another and are preferably coupled to the terminals of the LED light source via vias.

[0018] According to a particularly preferred embodiment, the inner housing may have a bearing housing for attaching the lighting device to the support arm, and this bearing housing is particularly configured to receive the support arm rotatably. This aspect further emphasizes the idea that the inner housing is an actual component of the light housing, whereby the lighting device can be attached to the support arm, and more generally to the support structure, with high reliability over a long period of time.

[0019] The thermal conductivity of the material of the inner housing is approximately 100 times greater than that of the material of the outer housing. In particular, the inner housing may be composed of aluminum or magnesium, and particularly preferably is a die-cast part of aluminum or magnesium.

[0020] For an efficient effect regarding heat transfer between the inner housing and the outer housing, it is required that the two components are in surface contact with each other (note: in the original text, "flachig aneinander liegen"), and in particular, there are no heat-insulating air bubbles. For this reason, it has been found that it is particularly advantageous to directly contact the outer housing with the inner housing by injection molding a plastic material onto the inner housing to form the outer housing. In this case, since the two components are made of different materials, a strong bond cannot be obtained, but sufficient heat transfer from the inner housing to the outer housing is still ensured. Furthermore, if the outer housing at least partially covers the edge of the inner housing, the two housings are reliably connected even without a connection by material bonding.

[0021] In conclusion, by means of these various measures, a medical light housing is provided that can dissipate heat to the surroundings uniformly, over a wide range, and homogeneously even when a strong local heat generation concentration occurs.

[0022] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. The drawings are as follows.

Brief Description of the Drawings

[0023] [Figure 1]An exemplary embodiment of the lighting device according to the present invention, which is arranged in a support system of a dental treatment unit (note: in the original text, it is zahnarztlicher Behandlungsplatz), is shown. [Figure 2] It is an enlarged view of the lighting device of FIG. 1. [Figure 3] It is an internal view of a light housing in which an LED substrate is arranged inside. [Figure 4] It is a cross-sectional view of FIG. 3. [Figure 5] It is a front view of an LED substrate provided with an LED light source. [Figure 6] It is a rear view of the LED substrate. [Figure 7] It is another internal view of the lighting device in which a clamp element for holding the LED substrate is arranged inside. [Figure 8] It is a cross-sectional view of FIG. 7. [Figure 9] It is a schematic diagram explaining heat dissipation achievable by the solution means according to the present invention.

Embodiments for Carrying out the Invention

[0024] FIG. 1 shows an overview of a dental medical lighting device 100 according to the present invention. This lighting device 100 is arranged in a support structure 110 which is part of a dental treatment unit not shown, for example. The support structure 110 and the holding part of the lighting device 100 located in the support structure 110 will be described in more detail below. As is known in dental lighting devices, the position of the lighting device 100 can be easily adjusted and properly aligned by having a plurality of joints.

[0025] The light housing 10, shown in detail in Figure 2, has a basically cup-shaped form and consists of a bottom region 11 that forms the back of the lighting device 100 and a circumferential wall region 13 that defines the light emission opening 18 (see, for example, Figure 4). In this exemplary embodiment, the light housing 10 is generally constructed in the shape of a truncated pyramid, so that the light emission opening 18 is substantially square. However, it is also conceivable to make the light housing 10 truncated cone-shaped or to make the light emission opening 18 elliptical. Importantly, a generally flat bottom region 11 is formed, which is used to support the light source as will be described in detail later, and the wall region 13 extends in a closed circumferential shape from the bottom region 11 to the light emission opening 18.

[0026] As further shown in Figure 2, in this embodiment, the light housing 10 is provided with two gripping elements 15 arranged opposite each other, which make it possible to grip the lighting device 100 and adjust its position or orientation. The joints of the support system described above are configured to maintain the lighting device 100 in a set position and orientation.

[0027] The components of the light housing 10 shown in Figure 2, namely its outer surface and the gripping element 15 preferably integrally formed therewith, are formed by a first component of the light housing 10, and are hereinafter also referred to as the outer shell 20. This outer shell 20 is preferably a single piece (einstuckige) and is made of plastic, i.e., an electrically insulating material. This makes it possible to touch the lighting device 100 without the risk of electric shock. In addition, the use of plastic generally provides a better tactile feel compared to metal.

[0028] The illustrated shape of the light housing 10, including the gripping element 15, can be easily manufactured using plastic material in injection molding. In this case, the corresponding structure can be realized with high precision, resulting in a light housing 10 with a high-quality exterior. On the other hand, plastic itself has low thermal conductivity, and the heat generated during the operation of the lighting device 100 is usually not easily dissipated to the surroundings through the plastic housing. In particular, there is a problem in that the heat generated locally and concentrated cannot be efficiently and uniformly dispersed.

[0029] To solve this problem, according to the present invention, the housing 10 is configured as a two-layer structure, that is, in addition to the outer shell 20, it preferably has an inner shell 30 made of a single material. The inner shell 30 has significantly different thermal properties from the outer shell 20, thereby compensating for the shortcomings of the plastic material of the outer shell 20. This concept will be described in detail below with reference to Figures 3 and 4.

[0030] Figure 3 shows the interior of the light housing 10, which is closed by a light-transmitting cover (translator's note: the original text uses "lichtdurchlassig") which is not shown in detail. Figure 4 is a cross-sectional view of Figure 3 along axis II.

[0031] According to the present invention, a cup-shaped inner shell 30 is positioned inside the plastic outer shell 20, as described above. This inner shell 30 is made of metal, as will be described later, and constitutes a bottom region 31 corresponding to the bottom region 11 of the light housing 10, from which a circumferential wall region 33 extends in the direction of the light emission opening 18. The inner shell 30 and the outer shell 20 are in surface contact, but are not joined together because they are made of different materials.

[0032] The substantially flat surface of the bottom region 31 of the inner shell 30 is used to support the light source 50. In the illustrated exemplary embodiment, the light source 50 is formed by a square circuit board 51 with an LED light source 52 positioned in the center. The LED light source 52 can consist of one or more LEDs or a combination of multiple LEDs. As can be seen from the figure, the LED light source 52 is preferably positioned only in the central region of the circuit board 51 and therefore has very small dimensions. It is also possible to position the LEDs over a wide area of ​​the circuit board 51. However, the modified form shown in the figure has the advantage that the light from the substantially point light source used here can be controlled more effectively and efficiently by appropriate optical means. As a result, the quality of illumination is improved, and with appropriate optical means, it is possible to illuminate areas, particularly surgical or examination areas, uniformly and without shadows.

[0033] A preferred exemplary embodiment of the implementation of the LED light source 52 is shown in Figure 5. In this example, the LED light source 52 is composed of two parallel series circuits 53a and 53b, each series circuit consisting of three LEDs in series. Therefore, by selectively activating the two LED groups 53a and 53b, different lighting modes can be selected according to each medical application.

[0034] The two LED groups together occupy approximately 1% of the total area of ​​the LED substrate 51. This indicates that it is extremely compact, a nearly point light source, and can efficiently shape its light to illuminate the medical work area. Each of the three series-connected LEDs has four electrical connection terminals (anode and cathode) that also function as heat conductors. To reduce the heat generated as thermal hot spots within the closed housing as quickly as possible, distribute it uniformly across the housing 10, and further dissipate the heat, the electrical connection terminals are through-connected to the metal back of the circuit board 51 and connected to a heat conductive pad 55 provided therein.

[0035] For efficient interaction between the LED light source 52 and the optical system (not shown), it is necessary to precisely position the LED light source 52 within the light housing 10. For this purpose, structural elements in the shape of pins or bridges 32 are formed on the upper side of the bottom region 31 of the inner shell 30, and these penetrate openings 54a and 54b formed in the circuit board 51. This ensures that the circuit board 51, and consequently the light source 50, are securely mounted in the designated position within the housing 10.

[0036] As shown in Figure 6, in a preferred embodiment, one of the two openings in the circuit board 51 is formed as a closed hole 54a having a cross-sectional shape that conforms to the outer shape of the bridge 32, and the other opening is formed as an elongated hole 54b. With this configuration, the circuit board 51 is fixed in a predetermined position within the hole 54a, and on the opposite side it is movable relative to the inner shell 30, i.e., floating. This prevents stress within the circuit board 51 that could ultimately lead to damage, even if the circuit board 51 and the inner shell 30 expand differently when temperature changes occur.

[0037] By providing the aforementioned multiple thermal conductive pads 55 on the back surface of the circuit board 51 shown in Figure 6, a thermally optimized coupling between the light source 50 and the inner shell 30 can be obtained. These thermal conductive pads 55 spread radially or fan-shaped from the center of the circuit board 51 outwards and make surface contact with the upper surface of the bottom region 31 of the inner shell 30. These thermal conductive pads 55 form eight electrically insulated segments and preferably cover 80% to 90% of the circuit board area in total, first distributing the heat generated from the centrally located LED light source 52 across the entire circuit board 51, and then transferring that heat to the bottom region 31 of the inner shell 30. To improve heat transfer from the circuit board 51 to the inner shell 30, preferably, a suitable interface material with thermal conductivity and electrical insulation, such as thermal conductive grease or thermal conductive sheet, is provided.

[0038] The aforementioned bridge or pin 32 initially serves only to correctly align the LED circuit board 51 with the upper surface of the inner casing 30. The actual fixing of the circuit board 51 is performed by the clamp element 40 shown in Figures 7 and 8. The clamp element 40 constitutes a frame that elastically presses against the upper surface of the circuit board 51. In the illustrated exemplary embodiment, the clamp element 40 is attached to the inner casing 30 by screw connections (Schraubverbindung), in which case the aforementioned bridge 32 is not only used for aligning the circuit board 51 but also constitutes a screw passage through which two screws that cooperate with the clamp element 40 are screwed. Furthermore, as shown in Figure 7, the clamp element 40 may be hooked onto the housing 10 by an additional arm or bridge.

[0039] In principle, other methods of mounting the circuit board 51 inside the housing 10 are conceivable. However, the illustrated solution has the advantage of providing particularly good thermal coupling and avoiding the generation of stress when the temperature changes, because the circuit board 51 is pressed over a wide area against the upper surface of the bottom region 31 of the inner shell 30.

[0040] Heat is primarily dispersed from the bottom region 31 of the inner shell 30, mainly through that region. This also applies to at least a portion of the wall region of the housing 10. As shown in the cross-sectional views of Figures 4 and 8, the inner shell 30 extends into the wall region 33 of the housing 10, but does not reach the actual light-emitting aperture 18. Therefore, the plastic outer shell 20 protrudes beyond the inner shell 30 in the wall region, resulting in a form-fitted connection (formschlussige Verbindung) between the two shells 20 and 30. In particular, the plastic outer shell 20 can be equipped with additional structural elements 28 in the wall region facing the light-emitting aperture 18. These can be fitted with a light-transmitting cover and / or optical elements that affect the light emitted from the light source 50.

[0041] The light housing 10 has a bearing housing 38 on one side of the wall region 13. This allows the lighting device 100 to be rotatably mounted on the support arm 110. The bearing housing 38 forms a substantially cylindrical opening in the wall region 13 of the housing 10, into which the corresponding end 115 of the support arm 110 engages. The housing 10 is pivotable around the longitudinal axis of the bearing housing 38 by the corresponding bearing. The bearing housing 38 is preferably an integral part of the inner shell 30, which has the advantage of being made of metal like the entire inner shell 30, and therefore capable of withstanding large forces. This allows the lighting device 100 to be permanently, reliably and safely mounted on the support arm 110 without the risk of wear, even if the weight of the lighting device 100 increases (for example, by additional accessories not shown in detail).

[0042] Thus, the inner shell 30, as part of the light housing 10, contributes advantageously to both the heat sink of the light source 50 and the pivotable mounting of the lighting device 100 to the support arm 110.

[0043] The two-layer structure of the light housing 10, having an inner shell 30 and an outer shell 20, allows heat generated from the LED light source 52 to be efficiently and safely dissipated to the surroundings. This is because the inner shell 30 is mainly coupled to the LED substrate 51, and its thermal conductivity is several times (preferably at least about 100 times) higher than that of the plastic material of the outer shell 20. First, locally generated heat is dispersed over a wide area, namely both the bottom region 31 and the wall region 33 of the inner shell 30. Because the inner shell 30 and the outer shell 20 are in surface contact, heat is further transferred from the inner shell 30 to the outer shell 20 and finally dissipated to the surroundings via the outer shell 20. In this case, since the outer shell 20 has a significantly larger surface area, the low thermal conductivity of the outer shell 20 is no longer a disadvantage.

[0044] In fact, by using plastic material for the outer shell 20, even the formation of hot spots on the surface of the lighting device and within the area of ​​the LED light source 52 is prevented. Instead, as shown in Figure 9, the outer surface of the light housing 10 is heated almost uniformly and homogeneously over an entire area that roughly coincides with the dimensions of the inner shell 30. The two areas 150 and 151 enclosed by dashed lines indicate areas on the surface of the housing where the temperature rises during the operation of the lighting device 100, and within these areas the temperature remains almost constant. The edges of these areas also show the transition of the wall area of ​​the housing 10 to an area composed solely of the outer shell 20, and it can be seen that the temperature continuously decreases outward from this boundary. However, across the entire area of ​​the inner shell 30, heat is uniformly released to the surrounding environment at a relatively low temperature.

[0045] The favorable interaction between the outer shell 20 and the inner shell 30 is facilitated by the fact that both shells 20 and 30 are in surface contact without the entrainment of interfering air. This can be achieved, particularly preferably, by first preparing the inner shell 30 and then injection molding the plastic material on which the outer shell 20 will form. This can be done, for example, by using an injection molding process in which the inner shell 30, which was initially manufactured as a die-cast part, is placed in an injection molding mold. As mentioned above, this method does not form a material bond between the outer shell 20 and the inner shell 30. However, since full contact between both shells 20 and 30 is ensured, and furthermore, as shown in the cross-sectional view, shape fitting is also ensured between the two parts by the fact that the outer shell 20 overlaps the inner shell 30 at least partially.

[0046] The procedure described above also has the advantage that the areas constituting the outer contour of the light housing 10 can be manufactured with high precision in the injection molding process. In contrast, the inner shell, for example, made of aluminum or magnesium, can be manufactured with much lower precision and does not require complicated post-processing.

[0047] In conclusion, the above-described solution provides a light housing for medical, and especially dental, applications that can be manufactured using a relatively simple method and that can dissipate heat very effectively, even from very small light sources.

Claims

1. A dental treatment lighting device (100) for illuminating the oral cavity of the surgical field, - A light source (50) having at least one LED light source (52) arranged on a circuit board (51), - A cup-shaped housing (10) that houses the light source (50) and constitutes a light-emitting opening (18) for emitting light, Equipped with, The housing has a bottom region (11) for supporting the circuit board (51) in surface contact, and a wall region (13) that extends circumferentially from the bottom region (11) to the light emission aperture (18), The housing (10) is composed of a plastic outer shell (20) and a metal inner shell (30) that is in contact with the inside of the outer shell (20). The circuit board (51) is in thermal surface contact with the inner shell (30) which extends beyond the bottom region (11) into the wall region (13). A dental treatment lighting device characterized by the following features.

2. The outer shell (20) protrudes beyond the inner shell (30) in the wall region (13) of the housing (10) and extends to the light emission opening (18). The dental treatment lighting device according to feature 1.

3. The outer shell (20) has mounting means (28) in the wall region (13) facing the light emission aperture (18) for holding a light-transmitting cover that closes the light emission aperture (18) and / or an optical element that affects the light emitted from the light source (50). The dental treatment lighting device according to feature 2.

4. The outer shell (20) constitutes one or more gripping elements (15). The dental treatment lighting device according to feature 1.

5. The inner shell (30) has a structural element (32) in the bottom region (11) for positioning the circuit board (51) in a predetermined position, The structural element (32) constitutes a pin or bridge that penetrates the centering opening (54) formed in the circuit board (51). The dental treatment lighting device according to feature 1.

6. The circuit board (51) has two centering openings (54), One of them (54a) has a cross-section that conforms to the outer shape of the pin or the bridge, The other centering opening (54b) is configured as an elongated hole that allows relative displacement between the circuit board (51) and the inner shell (30). The dental treatment lighting device according to feature 5.

7. The circuit board (51) is further provided with a frame-shaped clamping element (40) that elastically presses the circuit board (51) against the inner shell (30). The dental treatment lighting device according to claim 5 or 6.

8. The clamp element (40) is attached to the inner shell (30) by the screw holding portion (45), and the structural element (32) constitutes a screw passage for attaching the clamp element (40). The dental treatment lighting device according to feature 7.

9. The LED light source (52) is positioned in the center of the circuit board (51) and occupies only about 1% of the area of ​​the circuit board (51). The LED light source (52) is composed of two circuits, and each of the two circuits is a series circuit of multiple LEDs. The dental treatment lighting device according to feature 1.

10. The circuit board (51) has a thermal conductive pad (55) on its back side opposite to the LED light source (52) that covers at least 80% of the area of ​​the circuit board, and the thermal conductive pad (55) extends radially or in a fan shape from the center outward of the circuit board (51). The dental treatment lighting device according to feature 1.

11. The heat conductive pads (55) form regions that are electrically insulated from each other, and each of these regions is connected to the terminals of the LED light source (52) via vias. The dental treatment lighting device according to claim 10.

12. The inner shell (30) has a bearing housing (38) for holding the lighting device (100) on the support arm (115), and the bearing housing (38) is configured to rotatably receive the support arm (115). The dental treatment lighting device according to feature 1.

13. The thermal conductivity of the material of the inner shell (30) is approximately 100 times greater than that of the material of the outer shell (20). The dental treatment lighting device according to feature 1.

14. The inner shell (30) is made of aluminum or magnesium, and the inner shell (30) is a die-cast part made of aluminum or magnesium. The dental treatment lighting device according to feature 1.

15. The outer shell (20) is formed by injection molding of a plastic material onto the inner shell (30), so that the outer shell (20) is in direct contact with the inner shell (30) and the outer shell (20) at least partially overlaps the edge (33) of the inner shell (30). The dental treatment lighting device according to feature 1.

Images