High-uniformity light spot shaping mouth lamp

Abstract

The invention discloses a high-uniformity mouth lamp with a light spot shaping function. The mouth lamp with the high-uniformity light spot shaping function comprises a light emitting unit, the optical engine is arranged behind the light-emitting unit along a light path and comprises a transmission-type light mixing body which is arranged close to the light-emitting unit and is used for receiving and mixing light rays emitted by the light-emitting body so as to form mixed light beams with uniform colors; the light gathering unit is arranged on the light emitting side of the transmission-type light mixing body and used for gathering the mixed light beams; and the shaping unit is arranged on the light emitting side of the light condensing unit and is used for shaping the converged light beams into light spots in a preset shape. According to the high-uniformity light spot shaping mouth lamp, the problems that in the prior art, light spot illumination is not uniform, colors are separated, and the illumination mode is single are solved.

Description

Technical Field

[0001] This application relates to the field of medical lighting equipment technology, and in particular to an oral lamp with high uniformity spot shaping. Background Technology

[0002] Dental lamps are crucial equipment in dental treatment, and their lighting performance directly affects the accuracy of the dentist's observation of lesions and the safety of the procedure. Traditional dental lamps mostly use halogen lamps and other heat source light sources, which have inherent defects such as inaccurate color temperature, poor color rendering, high heat generation, high energy consumption, and short lifespan.

[0003] In recent years, although LED light sources have been introduced into new dental lamps, existing designs still face many challenges. New dental lamps typically employ a direct array of multiple LEDs. Due to the spatial separation of different colored LEDs, the main rays of different colors cannot overlap on the target plane when imaged through a single lens, resulting in a red / blue rainbow edge at the spot. In existing technologies, switching between focused (deep cavity) and floodlight (wide area) beams usually requires mechanically moving the lens or replacing the lamp head. This mechanical structure is complex, easily damaged, and difficult to sterilize. Furthermore, existing electronic zoom solutions often sacrifice spot uniformity, failing to maintain high-quality light mixing effects in both modes. Summary of the Invention

[0004] This application aims to provide an oral lamp with high uniformity spot shaping to solve the problem of color separation at the edge of the spot that may exist in the prior art.

[0005] To achieve the above objectives, this application provides an oral lamp with high uniformity spot shaping.

[0006] A dental lamp light-emitting unit with high uniformity spot shaping; comprising:

[0007] Light-emitting unit; and

[0008] An optical engine is disposed after the light-emitting unit, the optical engine comprising:

[0009] A transmissive light mixer, disposed adjacent to the light-emitting unit, is used to receive and mix the light emitted from the light-emitting unit to form a mixed light beam;

[0010] A focusing unit, disposed on the light-emitting side of the transmissive light mixer, is used to converge the mixed light beam; and

[0011] A shaping unit is disposed on the light-emitting side of the focusing unit and is used to shape the converged light beam into a light spot of a preset shape.

[0012] This sequential optical path design, consisting of "emission-mixing-focusing-shaping," allows for graded control of the beam's color, collimation, and spatial distribution, contributing to high-quality lighting effects. More specifically, the mixing element is responsible for "eliminating chromatic aberration," while the focusing unit is responsible for "collecting energy." The air gap between them plays a crucial role in "pupil matching," enabling the small-diameter mixing element to fit a large-diameter focusing lens, achieving both thorough mixing and extremely high light energy utilization. The focusing unit first "collimates" the beam, providing the shaping unit with a high-quality parallel incident light field. This allows the shaping unit (such as a Fresnel lens or compound eye) to focus on "spot morphology control" to obtain a sharp-edged rectangular spot.

[0013] Another aspect of this application provides an oral lamp capable of switching between wide-area illumination and deep cavity illumination modes. By dividing the light-emitting unit into two groups of light-emitting elements with different axial positions and selectively driving them by a controller, electronic switching between wide-area illumination and high-collimation deep cavity illumination can be achieved without mechanical moving parts.

[0014] By integrating a specific wavelength excitation source into one of the light-emitting elements, the oral lamp can switch between conventional illumination and fluorescence diagnostic data acquisition modes, achieving integrated diagnosis and treatment. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of one of the high-uniformity spot shaping oral lamps provided in this application;

[0016] Figure 2 yes Figure 1 A cross-sectional schematic diagram of a dental lamp providing high uniformity spot shaping;

[0017] Figure 3 This is the book Figure 1 An exploded view of an oral lamp with high uniformity spot shaping is provided.

[0018] Figure 4 yes Figure 1 A schematic diagram of a simulated spot of an oral lamp for high uniformity spot shaping is provided;

[0019] Figure 5 yes Figure 1 A schematic diagram of the optical path output of an oral lamp with high uniformity spot shaping is provided.

[0020] Figure 6 This is a schematic diagram of the internal structure of an oral lamp with high uniformity spot shaping provided in the second embodiment of this application;

[0021] Figure 7 This is a structural diagram of the light-emitting unit included in a high-uniformity light spot shaping oral lamp provided in the third embodiment of this application.

[0022] Explanation of reference numerals in the attached drawings: 1. Light-emitting unit; 2. Optical engine; 20. Transmissive light mixer; 22. Focusing unit; 24. Shaping unit; 242. Shaping exit surface; 240. Shaping incident surface; 3. Supporting cup structure; 30. Supporting platform; 32. Annular folded edge; 34. Annular boss; 342. Positioning hole; 26. Dichroic beam splitter; 112. Second light-emitting body group; 110. First light-emitting body group; 10. Substrate; 11. Light-emitting body; 13. Miniature laser pointer; 21. Light shield; 210. Cylinder shell; 212. Mounting ear; 241. Lug; 301. Slot. Detailed Implementation

[0023] The following is in conjunction with the appendix Figure 1-7 The oral lamp with high uniformity spot shaping provided in this application will be described in further detail.

[0024] Example 1

[0025] Please see Figure 1-5 This embodiment demonstrates the basic optical structure of a dental lamp with high uniformity beam shaping, the core of which lies in solving the key problems of uneven beam shape and color separation in traditional LED dental lamps. The dental lamp with high uniformity beam shaping shown in this embodiment includes a light-emitting unit 1 and an optical engine 2. The optical engine 2 includes a transmissive light mixer 20, a focusing unit 22, and a shaping unit 24.

[0026] In this embodiment, two types of LEDs 11 are mounted on the substrate 10 of the light-emitting unit 1: one set is a pure white LED with high color rendering (e.g., color temperature 5500K, CRI>90), and the other set is a warm white or yellow LED (e.g., color temperature 3000K). By adjusting the ratio of the driving current of the two sets of LEDs, for example, through a controller, the color temperature can be continuously adjusted.

[0027] The specific structure of optical engine 2 is as follows:

[0028] The transmissive light mixer 20 is preferably a square-section light guide column made of high-transmittance PMMA or optical glass. The transmissive light mixer 20 is a solid, transparent transmissive light mixer, which is disposed on the light-emitting end face of the light-emitting unit 1, and the light undergoes multiple total internal reflections inside it.

[0029] Specifically, the light-incident surface of the transmissive light mixer 20 is not tightly fitted to the light-emitting unit 1, but rather has an axial thermal isolation gap of 0.1mm to 0.5mm. This gap provides two technical benefits: First, it blocks heat conduction: the light-emitting unit 1 generates high heat during high-power operation. This air gap cuts off the direct heat conduction path to the transmissive light mixer 20 (typically made of PMMA or PC material), effectively preventing yellowing, carbonization, or thermal deformation of the light-incident surface due to prolonged high temperatures, thus ensuring the lifespan of the optical engine. Second, it provides fault tolerance and optical coupling: this gap allows light emitted from LEDs located at the edge of the light-emitting unit 1 to have a small free diffusion space before entering the light mixer, avoiding the risk of pressure damage due to LED packaging tolerances, while also improving the coupling efficiency of edge light.

[0030] To further optimize the optical path quality, a light shield 21 is fitted or configured on the outer periphery of the sidewall of the transmissive light mixer 20, with a small gap between the light shield 21 and the transmissive light mixer 20. The light shield 21 is used to reflect stray light escaping from the sidewall of the transmissive light mixer 20 back into the transmissive light mixer 20, preventing some light source from being wasted and absorbed by the carrier cup, thus causing light loss. Specifically, the light shield 21 is a cylindrical structure, including a cylindrical shell 210 and mounting ears 212 on opposite sides, which facilitate fixing to the substrate 10 where the light-emitting unit 1 is located. The inner wall surface of the light shield 21 is coated with a reflective layer or has a mirror silver structure.

[0031] Meanwhile, to ensure sufficient light mixing, the structural parameters of the transmissive light mixer 20 have been optimized, specifically, the ratio of the length (L) of the transmissive light mixer 20 to its equivalent cross-sectional diameter (D) is set to be greater than or equal to 3. This aspect ratio, combined with the lateral light-blocking effect of the light shield, ensures that the light from different light emitters is thoroughly and uniformly mixed before emission without any side leakage, ultimately forming a mixed beam with clear boundaries and uniform color.

[0032] The focusing unit 22 can be a single or a group of aspherical lenses, which are disposed on the light-emitting side of the transmissive light mixer 20 to converge or initially collimate the homogenized mixed beam.

[0033] The shaping unit 24 is disposed on the light-emitting side of the focusing unit 22 and is used to reshape the converged light beam to form a uniform light spot of suitable size and shape for oral illumination at a preset illumination distance. The unit has a shaping incident surface 240 close to the focusing unit 22 and a shaping exit surface 242 away from the focusing unit 22.

[0034] In one embodiment, the shaping unit 24 is a composite curved Fresnel lens; for example, such as Figure 1-3 As shown,

[0035] The shaping unit 24 includes a shaping incident surface 240 that protrudes toward the focusing unit 22 and a shaping exit surface 242 that is a Fresnel microstructure facing away from the focusing unit 22; the protruding incident surface 240 has positive optical power and is configured to pre-compress the divergence angle of the incident beam inside the lens medium, so that the light reaches the Fresnel microstructure exit surface 242 at a reduced incident angle, thereby reducing the draft depth of the Fresnel tooth profile and reducing optical shading.

[0036] The shaped exit surface 242 undertakes the main functions of converging and projecting light. By "collapsed" a continuous curved lens into a series of concentric rings, the Fresnel lens retains the powerful light-converging ability of an aspherical lens while greatly reducing the thickness and volume of the lens.

[0037] Specifically, in this embodiment, the incident light surface 240 is defined as a convex curved surface (such as an aspherical surface) that bears 30%-60% of the system's optical power. When light enters this incident light surface with a specific optical power, a first non-zero angle refraction occurs. The physical essence of this process is "medial compression of the light divergence angle": that is, after the edge light rays are refracted by the incident light surface, the angle between the light ray vector and the optical axis during their propagation inside the lens medium is significantly reduced. Compared with the prior art where the incident light surface is planar, the light rays no longer approach the exit light surface in a large-angle divergence state, but are transmitted in a posture closer to parallel light.

[0038] Choosing the specific numerical range of 30%-60% is the optimal solution derived from extensive optical simulations and injection molding experiments, and it exhibits significant critical technical effects.

[0039] When the ratio is less than 30%, the incident surface is too flat, the pre-deflection capability of the light is insufficient, and the transmission angle in the medium is still large, which forces the output surface to maintain a deep tooth structure in order to achieve collimation, resulting in the inability to solve the shadow lock problem.

[0040] When the ratio is higher than 60%, although the burden on the light-emitting surface is further reduced, the excessive convexity of the light-incident surface will cause the thickness of the lens center to increase sharply (causing injection molding shrinkage defects), and the excessively small radius of curvature will introduce high-order spherical aberrations that are difficult to correct, resulting in deterioration of the uniformity of the light spot.

[0041] Only within the range of 30%-60% can the transmission angle within the medium be compressed to the maximum extent while ensuring molding quality. Specifically, this embodiment limits the incident surface to bear 30%-60% of the optical power of the system. This ratio is calculated using the three basic physical parameters of the lens and satisfies the following relationship:

[0042] 0.3≤ ≤0.6; (1)

[0043] The meanings of the parameters in the formula are as follows:

[0044] f (effective focal length of the lens): refers to the effective focal length of the entire Fresnel lens system, in millimeters (mm).

[0045] n (refractive index of the material): refers to the refractive index of the medium material used in the lens;

[0046] R (incident surface radius): refers to the radius of curvature of the convex incident surface at the apex of the optical axis, and the unit is millimeters (mm).

[0047] Based on the aforementioned optical power distribution, the angle of incidence when light reaches the exiting surface is significantly reduced. According to Snell's law, the refractive power required for the exiting surface to collimate it is consequently reduced. This produces a decisive chain reaction in the geometry: the tilt angle of the working refractive surface of the Fresnel microstructure is significantly reduced.

[0048] Specifically, each annular cross-section of the Fresnel microstructure can be considered as a right-angled triangle. Here, the tooth pitch (p) corresponds to the width of the triangle's base, the tooth depth (h) corresponds to the triangle's vertical height, and the tilt angle (α) corresponds to the base angle. According to the tangent trigonometric relationship, given a constant base width (tooth pitch p), the vertical height (tooth depth h) is proportional to the tangent of the base angle (tilt angle α).

[0049] Therefore, as the tilt angle α decreases, the tooth depth h inevitably decreases as well. With the tooth pitch remaining constant, the decrease in tilt angle directly leads to a significant, non-linear reduction in the vertical height (i.e., tooth depth) of the non-working draft surface (preferably below 0.2 mm). Ultimately, the low-profile non-working draft surface exits the main path of light transmission, allowing light to "pass over" it and be fully projected onto the gently sloping working refractive surface. This structural-optical path correspondence—"incident surface compresses the internal transmission angle—leading to a reduction in the slope of the exit surface—and thus physically achieving shallower teeth"—eliminates shadow occlusion from a geometrical optical perspective, achieving a dual improvement in both luminous efficiency and beam sharpness.

[0050] In another embodiment, the shaping incident surface 240 remains a smooth arc surface, while the shaping exit surface 242 is replaced with a compound eye lens array surface.

[0051] The shaping incident surface 240 primarily functions as a "field lens" here. It is responsible for adjusting the angle of the principal ray of the incident beam, ensuring it is as perpendicular as possible or incident at a predetermined angle onto the compound eye lens array on the rear surface. The shaping exit surface 242, in the form of a compound eye lens, is composed of numerous tiny sub-lens units arranged closely together. Each sub-lens unit is equivalent to an independent micro-projector, independently projecting and superimposing the incident beam segment onto the target illumination area (oral cavity).

[0052] The aperture shape of the sub-lenses in the compound eye lens array directly determines the shape of the illumination spot. By designing the shaping exit surface 242 as a rectangular sub-lens array, a rectangular spot with extremely clear boundaries can be generated, conforming to the shape of the oral cavity opening, preventing light from shining into the patient's eyes, and improving patient comfort. At the same time, the curved light-incident design corrects off-axis aberrations, so that the four corners of the rectangular spot are no longer blurred or distorted.

[0053] Specifically, in order to form the rectangular light spot shown in Figure 6, the physical aperture of each micro-sub-lens unit in the shaping unit 24 (especially the compound eye lens array) is designed to be rectangular. Based on the principle of optical integration, all micro-sub-lenses divide the incident beam and project it independently. These tiny rectangular light fields are superimposed in the target area, thereby forming a rectangular illumination spot with clear boundaries, uniform illumination, and matching the shape of the transverse opening of the oral cavity on a macroscopic scale, effectively preventing light from overflowing and irradiating the patient's eyes.

[0054] Furthermore, to integrate the circuit board of the light-emitting unit 1, the transmissive light mixer 20, the focusing unit 22, and the shaping unit 24 into a compact optical module, this embodiment also provides an integrated support cup structure 3. This support cup structure 3 is generally flared, with a support platform 30 at the larger opening end for stably fixing the shaping unit 24. It tapers towards the bottom along the flared opening, and its inner wall uses an annular folded edge 32 to axially position and secure the focusing unit 22. At its bottommost point, an annular boss 34 with a central positioning hole 342 is designed. This positioning hole 342 is used to embed the transmissive light mixer 20, while the outer bottom surface of the boss 34 is fixed to the circuit board on which the light-emitting element is mounted. In this way, from the light-emitting element on the circuit board to the shaping unit 24 at the front end, all optical and electronic components are firmly connected and kept coaxial by this single support cup, forming an integrated light engine that requires no complex alignment, has a stable structure, and is easy to assemble.

[0055] Furthermore, the focusing unit 22 has a low-curvature incident surface 22a and a high-curvature exit surface 22b; the shaping unit 24 has a convex incident surface 24a; the exit surface 22b of the focusing unit and the incident surface 24a of the shaping unit are arranged opposite to each other, and together they define a biconcave air lens region with negative optical power; the incident surface 22a is used to pre-compress the beam divergence angle, the exit surface 22b is used for main convergence, and the incident surface 24a compensates for the spherical aberration generated by the exit surface 22b through the air lens region. Together they shape large-angle light rays into a 'wavefront flat, edge-converging' laminar flow beam, which is then projected onto the Fresnel structure at the rear end.

[0056] More specifically, the radius of curvature R of the incident surface of the focusing unit 22 22inRadius of curvature R of the light-emitting surface 22out The incident surface curvature radius R24in of the shaping unit 24 satisfies the following spherical aberration suppression condition:

[0057] 2.5≤ R 22in / R 22out ≤3.5; (2)

[0058] 0.8≤ R 24in / R 22out ≤1.2; (3)

[0059] The combined effective focal length fsys of the optical engine 2 and the output aperture Dexit of the transmissive light mixer 20 are configured to satisfy a light efficiency constraint relationship:

[0060] 0.6≤ D exit / f sys ≤0.8; (4)

[0061] For formula (2), a specific asymmetric morphology factor optimization was performed on the focusing unit 22. At the physical level, this formula forces the focusing unit to exhibit a structural characteristic of a 'smooth front surface and steep rear surface'. For edge rays with extremely high divergence emitted from the transmissive light mixer 20 (incident angle typically >50°), the relatively smooth R... 22in This significantly reduces the incident angle of light onto the medium surface, thereby reducing interface reflection loss from over 15% in conventional designs to approximately 4%, based on Fresnel's equations, and greatly improving incident light coupling efficiency. Simultaneously, it allocates the majority of the refracted optical power to the rear surface R. 22out This allows light to maintain a longer optical path inside the lens, reserving the necessary physical space for subsequent aberration correction.

[0062] For formula (3), a 'biconcave air lens' with a specific optical power is constructed between the focusing unit 22 and the shaping unit 24. In terms of geometric optics, the convex surface of a glass lens usually introduces positive spherical aberration (premature convergence of edge rays). The air gap formed by the two sets of opposing convex surfaces, as defined by this formula, actually acts as a lens with a negative refractive index difference, producing negative spherical aberration with the opposite sign to positive spherical aberration. When the ratio is controlled within the critical range of 0.8 to 1.2, the negative spherical aberration produced by the air lens can precisely cancel the higher-order positive spherical aberration produced by the short focal length system. This 'reverse cancellation mechanism' causes the edge of the beam after beam expansion to converge to near the diffraction limit, thereby achieving a sharp cutoff of the illuminance gradient at the edge of the light spot without the need to add additional aspherical lenses, eliminating the 'halo' phenomenon commonly seen in diagnostic lighting.

[0063] Equation (4) defines the relative aperture or F-number level of the optical system. According to the illuminance law in geometrical optics, the central illuminance E of the image plane of an optical system is related to the system's F-number (i.e., f). sys / D exit The square of E is inversely proportional to the square of D, that is, E∝(D). exit / f sys ) ^2 .

[0064] The larger this ratio (i.e., the smaller the F-number), the stronger the light-gathering ability of the system and the higher the light energy density. This application sets this ratio in the high threshold range of 0.6 to 0.8, which is equivalent to setting the system to operate in a 'large aperture' state with an extremely low F-number (approximately F / 1.25 to F / 1.6). This configuration aims to overcome the deficiency of low light energy utilization in traditional telephoto systems and obtain ultra-high light flux density at the diagnostic spot.

[0065] Furthermore, in this embodiment, in order to ensure the reliability of fixing the shaping unit 24, a slot 301 is provided on the cup-bearing structure 3, and a lug 241 is provided on the shaping unit 24. The lug 241 cooperates with the slot 301 to fix the shaping unit 24. Figure 4 The simulated light spot effect formed at the final working distance (e.g., 700mm) is shown. Thanks to the synergistic effect of the aforementioned optical engine, the light spot exhibits the following significant characteristics:

[0066] Regular shape: It presents itself as a clearly defined rectangle, perfectly fitting the shape of the oral cavity opening;

[0067] Uniform illuminance: The illuminance distribution inside the light spot is extremely flat, with little difference in brightness between the center and the edge;

[0068] Clear cutoff line: The upper edge of the light spot has a steep brightness gradient, which effectively prevents light from overflowing and shining into the patient's eyes.

[0069] Please see Figure 5 The diagram illustrates the light path emission of this application. After being emitted from the light-emitting unit 1, the light first enters the transmissive light mixer 20. Within the light mixer, the light undergoes multiple total internal reflections, completely scattering and mixing light of different color temperatures in space. Subsequently, the light exits the light mixer, passes through an air gap for pre-diffusion (pupil expansion), and is then initially converged by the focusing unit 22. Finally, the converged beam passes through the shaping unit 24 to obtain a rectangular light spot.

[0070] Example 2

[0071] Based on Example 1, this embodiment further discloses an oral lamp structure with integrated laser indication function, aiming to solve the technical problems of poor doctor-patient communication and inaccurate indication during clinical operation.

[0072] like Figure 6 As shown, in addition to the basic structure of the optical engine 2 described in Embodiment 1, this embodiment also includes a miniature laser pointer 13 for providing auxiliary positioning and indication functions.

[0073] The miniature laser pointer 13 is preferably a module that emits green laser light with a wavelength of 515-530 nm, because the human eye is most sensitive to this wavelength and it remains clearly visible against a bright oral cavity lighting background. Compared to traditional red light (650 nm), green light has a higher Weber contrast against a white light background with high illuminance (typically 8000-30000 lux) in the oral cavity, making it easier for the naked eye to recognize.

[0074] To achieve coaxial coupling between the laser beam and the main illumination beam, this embodiment provides a feasible structure.

[0075] In this structure, a dichroic beam splitter 26 is positioned at a 45-degree angle inside the optical engine 2, between the focusing unit 22 and the shaping unit 24. A miniature laser pointer 13 is mounted on the side wall of the optical engine 2, with its beam path perpendicular to the main optical path and directed towards the beam splitter. The beam splitter's coating characteristics are: an average transmittance exceeding 90% for a broad spectrum of 380-700nm (or at least 390nm-700nm), while exhibiting high reflectivity only for a narrow band of green light in the 515-530nm range.

[0076] During operation, the main illumination beam from the focusing unit 22 is transmitted through the dichroic beam splitter 26; while the laser beam from the side is reflected and deflected by the dichroic beam splitter 26 by 90°, thus combining with the main illumination beam in space to achieve coaxial output.

[0077] Example 3

[0078] Please see Figure 7 This embodiment is basically the same as embodiment 1, except that in this embodiment, the switching between the two modes of "wide-area illumination" and "deep cavity illumination" is realized. This embodiment is an optical structure layout that realizes mechanical zoom without mechanical zoom by utilizing the principle of optical extension.

[0079] Specifically, the oral lamp is configured to switch between a wide-area illumination mode and a deep-cavity illumination mode by changing the number of LED chips in the lit state; wherein the wide-area illumination mode corresponds to a larger total luminous area S1, and the deep-cavity illumination mode corresponds to a smaller total luminous area S2; the parameters of the wide-area illumination mode and the deep-cavity illumination mode satisfy the following formula:

[0080] ≧K;(5)

[0081] and ≧ (6)

[0082] Where DoF1 is the depth of field of the light spot under wide-area illumination mode, and DoF2 is the depth of field of the light spot under deep cavity illumination mode;

[0083] K is the area transformation coefficient, and K≧4; making the depth of field DoF2 of the deep cavity illumination mode significantly greater than the depth of field DoF1 of the wide area illumination mode.

[0084] In this embodiment, the transmissive light mixer 20 is configured to convert changes in the spatial area of ​​the light-emitting unit 1 into changes in the divergence angle of the emitted beam. For this purpose, the light-emitting unit 1 employs a specific "centrally recessed" spatial layout:

[0085] The substrate 10 has a recessed structure in its central region. A second light-emitting body group 112 with a smaller total light-emitting area S2 is disposed at the bottom of the recessed structure to form a deep cavity illumination mode; a first light-emitting body group 110 with a larger total light-emitting area S1 is arranged around the recessed structure on the higher plane of the substrate to form a wide-area illumination mode. The depth of the recessed structure is calculated to compensate for the difference in axial object distance between the two light sources in different modes.

[0086] Regarding optical path coupling, the light-emitting end face of the transmissive light mixer 20 and the light-incident end face of the focusing unit 22 are not in close contact, but rather form a defined axial air gap. The axial distance of this gap is Δd, and its ratio to the focal length f of the focusing unit 22 is limited to the range of 0.05 ≤ Δd / f ≤ 0.3. This air gap design has dual technical advantages:

[0087] First, pupil expansion: This allows the light beam emitted from a finer light-mixing body to undergo moderate pre-diffusion in free space, ensuring that when the beam reaches the incident surface of the focusing unit, its beam cross-section precisely covers the effective aperture of the focusing unit. This enables the system to use a small-section, low-cost light-mixing body in conjunction with a large-aperture lens, significantly improving the light energy utilization rate of the lens surface.

[0088] Second, thermal isolation protection: This physical barrier blocks the direct conduction of heat from the high-temperature light mixing end face and LED substrate to the heat-sensitive focusing lens (usually made of PMMA material), effectively preventing the lens from undergoing curvature deformation due to long-term heating.

[0089] Based on the above structure, when the system switches to deep cavity illumination mode (activating S2), because the light source is approximately a point source and undergoes collimation transmission, the Rayleigh range of the light beam is significantly extended after passing through the pupil expansion and focusing unit. This means that the light spot can maintain high illuminance and clarity over a large axial depth range, eliminating the need for doctors to frequently adjust the lamp head position during deep root canal treatment.

[0090] To achieve high-quality lighting, this embodiment has specifically optimized the configuration of the two light sources:

[0091] The first light-emitting element group 110 (wide-area / high color rendering index): configured as a multispectral hybrid array. It includes high color temperature LEDs with a color temperature of 5700K-6500K and low color temperature LEDs with a color temperature of 2700K-3500K to achieve continuously adjustable color temperature. Preferably, it also includes cyan LEDs with a peak wavelength of 490-505nm and / or deep red LEDs with a peak wavelength of 630-660nm for spectral compensation to ensure that the color rendering index (CRI) reaches the medical-grade standard of Ra>95.

[0092] Second light-emitting element group 112 (deep cavity / functionalized): configured as a high-density integrated light source. It includes:

[0093] Deep cavity lighting source: Uses chip-scale packaged or flip-chip white LEDs with extremely small emitting surface area (<1mm²) to optically approximate point light sources to the greatest extent possible, thereby obtaining excellent collimation.

[0094] The transmissive light mixer 20 serves a dual function in this optical system:

[0095] First, as a light homogenizer: it utilizes multiple total internal reflections of light within the inner wall of the medium to perform spatial dimension integration and mixing of the incident beam. This process eliminates uneven brightness and color separation defects caused by the LED array arrangement, ensuring that the beam forms a secondary light source with highly uniform illuminance and color when it reaches the light-emitting surface of the light-mixing body.

[0096] Second, as an angle-preserving transmitter (angle domain preservation): based on the principle of conservation of optical extension, the through-type light guide can basically maintain the numerical aperture (NA) envelope characteristics of the incident beam while scattering the spatial distribution of light.

[0097] The specific working mechanism is as follows:

[0098] 1. Deep cavity illumination mode:

[0099] When the controller illuminates only the second light-emitting element group 112 located at the bottom of the recessed structure of the substrate, because this light-emitting element group is located at the center of the optical axis and has a small area (approximately a point light source), the light emitted by it mainly couples into the transmissive light mixer 20 at a small incident angle. Although these lights undergo multiple total internal reflections during transmission within the light mixer to achieve uniform brightness of the light-emitting surface, their overall emission divergence angle remains within a small range. This small divergence angle, after being converged by the focusing unit 22, can form a light column with a long Rayleigh range (depth of field) and highly concentrated energy, suitable for deep root canal treatment.

[0100] 2. Wide-area lighting mode:

[0101] When the controller illuminates the first light-emitting element group 110 surrounding the recessed structure, the light rays couple into the transmissive light mixer 20 at a large angle due to the light source's offset from the optical axis and its wide distribution range. Based on the angle-maintaining characteristic, the beam emitted from the light mixer has a large divergence angle. After passing through the focusing unit 22, this portion of the large-angle light rays achieves a higher magnification or a wider diffusion range, thus forming a wide-area light spot with a large coverage area and soft edge transitions.

[0102] By switching between 'small-angle light incident at the center' and 'large-angle light incident at the edge' as described above, and combining the angle-maintaining characteristics of the transmissive light mixer 20, this application achieves optical zoom without mechanical moving parts.

[0103] Example 4

[0104] This embodiment further expands the functionality of the oral lamp based on the dual-mode of embodiment 3, upgrading it from a pure lighting tool to a diagnostic aid.

[0105] In this embodiment, the configuration of the second light-emitting element group 112 (for deep cavity mode) disposed at the bottom of the recessed structure is further enriched. In addition to white LEDs, it also includes at least one emission source capable of emitting excitation light of a specific wavelength. Specifically, the excitation light is blue-violet light with a wavelength in the range of 395 nm to 415 nm.

[0106] Based on the above configuration, the controller is configured to perform the following diagnostic process: When the user selects to enter the data acquisition mode, the controller shuts down the first light-emitting element group 110 and independently activates the blue-violet LEDs in the second light-emitting element group 112. At this time, the dental lamp outputs a highly collimated excitation beam that inherits the excellent characteristics of the deep cavity mode. This beam can be precisely projected onto the tooth surface, effectively stimulating the metabolites (such as porphyrins) in the carious area to produce red or orange fluorescence, while healthy enamel exhibits green fluorescence. This high-contrast fluorescence response signal makes early lesions that are difficult to detect with the naked eye clearly visible, achieving integrated diagnosis and treatment.

[0107] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A high uniformity spot shaping dental lamp, characterized in that, The application relates to a high-uniformity light spot shaping oral cavity lamp, comprising: a light emitting unit (1) comprising at least two light emitters capable of emitting light rays of different color temperatures; and an optical engine (2) disposed behind the light emitting unit (1), the optical engine (2) comprising: a transmissive light mixing body (20) disposed adjacent to the light emitting unit (1) at an incident light end, the transmissive light mixing body (20) being a solid transparent light guide column with a polygonal cross section, configured to receive and mix light rays emitted from the light emitting unit (1) to form a mixed light beam; a light collecting unit (22) disposed at an exit light side of the transmissive light mixing body (20), configured to collimate or converge the mixed light beam; and a light shaping unit (24) disposed at an exit light side of the light collecting unit (22), configured to shape the converged light beam into a preset shape of an illumination light spot. The light shaping unit (24) comprises an array of compound eye lenses or a Fresnel lens; or 2. The high uniformity spot shaped mouth lamp of claim 1, wherein, The transmissive light mixing body (20) has a length to cross-sectional equivalent diameter ratio greater than or equal to 3; or Further comprising a miniature laser pointer (13) whose light beam is integrated into the light path of the optical engine (2) and used to project an indicator mark point at the center of the illumination light spot. The radius of curvature R of the light entrance surface of the condensing unit (22) 22in The radius of curvature R of the light exit surface 22out The radius of curvature R of the light entrance surface of the shaping unit (24) 24in The spherical aberration is suppressed by the following condition: Condition 1 : 2.5 < R 22in / R 22out ≤ 3.5; Condition 2: 0.8 < R 24in / R 22out ≤ 1.2; Furthermore, the combined effective focal length f of the optical engine (2) sys The light output aperture D of the transmissive light mixer (20) exit The distances between them are configured to satisfy the light effect constraint: 0.6 ≤ D exit / f sys ≤0.

8.

3. The high uniformity spot shaped mouth lamp according to claim 1 or 2, characterized in that, 4. The high-uniformity light spot shaping oral cavity lamp according to claim 1, wherein: the light emitting unit (1) comprises a first light emitter group (110) and a second light emitter group (112); the oral cavity lamp is configured to be switched between a wide area illumination mode and a deep cavity illumination mode by a controller; wherein the wide area illumination mode corresponds to lighting up the first light emitter group (110) with a total light emitting area of S1, and the deep cavity illumination mode corresponds to lighting up the second light emitter group (112) with a total light emitting area of S2; parameters of the wide area illumination mode and the deep cavity illumination mode satisfy the following formula: the transmissive light mixing body (20) is configured to convert area variation of the light emitting unit (1) into variation of divergence angle of the exiting light beam. K, K is an area conversion coefficient, and K > 4; The light emitting unit (1) comprises a substrate (10) with a recess structure at the center, the second light emitter group (112) is disposed in the recess structure, and the first light emitter group (110) is disposed on a plane where the recess structure openings are located and arranged around the recess structure.

5. The high uniformity spot shaped mouth lamp of claim 4, wherein, An axial air gap is formed between an exit light end surface of the transmissive light mixing body (20) and an incident light surface of the light collecting unit (22), the axial air gap is configured to pre-diffuse the light beam exiting from the light mixing body in free space to cover an effective light aperture of the light collecting unit (22).

6. The high uniformity spot shaped mouth lamp of claim 4, wherein, An axial distance of the axial air gap is Δd, and a ratio of the axial distance Δd to a focal length f of the light collecting unit (22) is limited in a range of 0.05≤Δd / f≤0.

3.

7. The high uniformity spot shaped mouth lamp of claim 6, wherein, The second light emitter group (112) comprises at least one emission source capable of emitting excitation light of a specific wavelength; and the controller is configured to, when the second light emitter group (112) is activated to enable a data acquisition mode, output a collimated light beam of the oral cavity lamp to irradiate a target tooth surface to excite and cause the target tooth surface to generate a fluorescence response signal for light-induced fluorescence analysis.

8. The high uniformity spot shaped mouth lamp of claim 4, wherein, ​ 9. The high uniformity spot shaped mouth lamp of claim 8, wherein, The specific wavelength of excitation light is blue-violet light with a wavelength in the range of 395 nm to 415 nm; and when the data collection mode is activated, the controller is further configured to turn off or significantly reduce the brightness of the white light emitted by the first light emitter group (110).

10. The high uniformity spot shaped mouth lamp according to any one of claims 1-9, wherein, Further comprising a bearing cup structure (3) for integrating the optical engine (2); the bearing cup structure (3) is a one-piece trumpet-shaped structure, which comprises: A bearing table (30) arranged at the opening end with larger opening for fixing the shaping unit (24); An annular folded edge (32) formed on the inner wall for axial positioning of the light collecting unit (22); and An annular boss (34) arranged at the bottom for embedding the transmission type light mixer (20) and fixing with the light emitting unit (1).

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