Light distribution switching method and light-emitting device

Abstract

The invention discloses a light distribution switching method and a light-emitting device, the light-emitting device comprises a first light-emitting unit and a second light-emitting unit, the first light-emitting unit is used for forming a first target light pattern, and the second light-emitting unit is used for forming a second target light pattern. The light intensity distribution of emergent light of the first light-emitting unit and the second light-emitting unit on a far-field observation plane has an overlapping interval; the method comprises the steps that the first light emitting unit and the second light emitting unit are driven, and contribution of the first light emitting unit and the second light emitting unit to overall light distribution is adjusted according to a preset output luminous flux proportion, and obtaining a plurality of light patterns including the first target light pattern, the second target light pattern and at least one composite light pattern formed by overlapping the first target light pattern and the second target light pattern. According to the technical scheme, various standard light types can be achieved through the electric control proportion under the condition that the light-emitting elements do not need to be replaced, the product type selection and inventory cost is reduced, and the installation flexibility and the application adaptability are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical technology, in particular to a light distribution switching method and a light emitting device. BACKGROUND

[0002] The light emitting element refers to a functional unit capable of converting electrical energy into visible light or near-visible light. The typical form includes a single or multiple semiconductor light emitting chips, a package, a primary optical element, and an optional secondary optical element, which work with a driving circuit to output a specified luminous flux and light distribution. The primary optical element is usually a package gel or a small shaped lens, which is used to complete the primary shaping of light and ensure the light output efficiency. The secondary optical element is usually an independent lens, a light-transmitting cover, or a reflector, which is used to precisely shape the far-field light distribution, so that the output meets the light distribution standards of road, indoor, or landscape scenes. The above structure is optimized in terms of target light distribution, light emitting area size, refractive index, installation geometry, and thermal conditions at the design stage. Once the structure is fixed, it is reproduced in the batch production with a fixed structure, thereby ensuring that the same type of light emitting element has stable and predictable optical output among different batches.

[0003] The existing light emitting element can usually only emit a specific optical angle or light type, because the free-form surface or geometric parameters of the secondary optical element are optimized around a single target function. The surface shape, light emitting surface position, air gap, and material refractive index jointly determine a unique far-field light intensity distribution. If the same hardware only changes the current or duty cycle through dimming, it mainly affects the luminous flux rather than the light distribution angle, and it is difficult to switch to another type of light. To adapt to different road sections and installation conditions, the industry generally replaces lenses of different angles or directly replaces light emitting elements of different angles. This piece-by-piece replacement strategy causes selection complexity, installation interruption, and inventory accumulation, and other chain problems. Therefore, there is an urgent need for technical personnel in the field to improve it. SUMMARY

[0004] The embodiments of the present application provide a light distribution switching method, which aims to solve the following technical problems: a single light emitting element can usually only output a specific optical angle, cannot flexibly cover multiple light distribution requirements on the same hardware, and users have to purchase and store multiple light emitting elements of different angles to meet the needs of multiple scene applications, resulting in large inventory size, high operating cost, and low on-site switching efficiency.

[0005] To achieve the above-mentioned purpose, the embodiments of the present application provide a light distribution switching method, which is applied to a light emitting device. The light emitting device includes a first light emitting unit and a second light emitting unit. The first light emitting unit is used to form a first target light type, and the second light emitting unit is used to form a second target light type. The light intensity distribution of the light emitted by the first light emitting unit and the second light emitting unit on a far-field observation plane has an overlapping interval. The method includes: The first light-emitting unit and the second light-emitting unit are driven, and the contribution of the first light-emitting unit and the second light-emitting unit to the overall light distribution is adjusted by a preset output luminous flux ratio, so as to obtain multiple light patterns including the first target light pattern, the second target light pattern and at least one composite light pattern formed by superposition of the two.

[0006] To achieve the above objectives, embodiments of this application also propose a light-emitting device, including a substrate, a first light-emitting unit, and a second light-emitting unit; The first light-emitting unit includes a first light-emitting source disposed on the substrate and a first lens covering the first light-emitting source. When the first light-emitting source is powered on, it cooperates with the first lens to form a first target light pattern. The second light-emitting unit includes a second light-emitting source disposed on the substrate and a second lens covering the second light-emitting source. When the second light-emitting source is powered on, it cooperates with the second lens to form a second target light pattern. The first light source and the second light source are located on the same side of the substrate, and the light intensity distribution of the first light source and the second light source on the far-field observation plane overlaps.

[0007] The technical solution provided in this application is based on the juxtaposition of two types of light-emitting units within the same light-emitting device. Each unit, through its own light source and corresponding lens, forms a preset first target light pattern and a second target light pattern, respectively. The spatial relationship between the two units is designed such that the light intensity distribution on the far-field observation plane has an overlapping interval, so that at any observation angle, the overall light intensity can be regarded as the weighted sum of the light intensities of the two units. During use, either unit can be driven individually to obtain the corresponding target light pattern, or both units can be driven simultaneously, and their contributions to the overall light distribution can be adjusted according to a preset output luminous flux ratio. When the ratio changes, the overall light pattern smoothly switches or transitions between the two target light patterns, forming a new composite light pattern in the intermediate interval, thereby achieving flexible output of multiple light distribution modes in one device.

[0008] This design effectively overcomes the limitations of fixed light patterns in traditional light-emitting elements. By allowing two types of light-emitting units to overlap in the far-field region, their output angular distribution becomes superimposed. Based on this, by adjusting the output luminous flux ratio, a correspondence between the target light pattern and the overall light pattern is established. This allows light pattern changes to no longer rely on the fixed design of a single lens, but rather to be expanded and switched through proportional control. With this mechanism, a single device can meet the needs of multiple standard light patterns, avoiding frequent replacement of components or lenses, reducing selection and inventory burdens, and improving the adaptability of the lighting system to different application environments. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0010] Figure 1 Diagram explaining the optical angle; Figure 2 This is a schematic diagram of the structure of an embodiment of the light-emitting device of the present invention; Figure 3 for Figure 2 A cross-sectional schematic diagram of the light-emitting device in the diagram; Figure 4 This is a schematic diagram of the light rays when the output luminous flux ratio of the first light-emitting unit to the second light-emitting unit is 1:1.2. Figure 5 This is a schematic diagram of the light pattern when the output luminous flux ratio of the first light-emitting unit to the second light-emitting unit is 1:1.2. Figure 6 This is a schematic diagram of the light when the output luminous flux ratio of the first light-emitting unit to the second light-emitting unit is 0:1 (i.e., the second light-emitting unit is lit up alone); Figure 7 This is a schematic diagram of the light pattern when the output luminous flux ratio of the first light-emitting unit to the second light-emitting unit is 0:1. Figure 8 This is a schematic diagram of the light pattern when the output luminous flux ratio of the first light-emitting unit to the second light-emitting unit is 1:1.6; Figure 9 This is a schematic diagram of the light pattern when the output luminous flux ratio of the first light-emitting unit to the second light-emitting unit is 1:2.0.

[0011] Explanation of icon numbers: 1. Substrate; 2. First light-emitting unit; 21. First light-emitting source; 22. First lens; 3. Second light-emitting unit; 31. Second light-emitting source; 32. Second lens; 4. First column; 5. Second column.

[0012] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0013] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0014] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0015] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the term "and / or" throughout the text includes three solutions; taking A and / or B as an example, it includes technical solution A, technical solution B, and a technical solution that simultaneously satisfies A and B. Furthermore, the technical solutions of various embodiments can be combined with each other, provided that they are feasible for those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0016] Light-emitting elements (LEDs) are the core components of modern lighting products, typically consisting of a light-emitting chip, primary optical structures (such as encapsulated colloids or miniature lenses), optional secondary optical components (such as independent lenses, light-transmitting covers, or reflectors), and matching driving circuitry. In engineering applications, LEDs not only need to output sufficient luminous flux but also meet specific light distribution requirements to satisfy the light projection angle and uniformity requirements of scenarios such as road lighting, indoor lighting, or landscape lighting. Light distribution is often referred to as optical angle or light pattern, which is the light intensity distribution trajectory plotted in the far field through photometric measurements. For example, please refer to... Figure 1 In the classification of the Illuminating Engineering Society (IESNA), Type II, Type III, Type IV, and Type V light patterns are categorized based on the main light distribution coverage of the luminaire in the road direction or laterally. Figure 1As shown in the example, the main light spot of Type II light pattern is concentrated in the range of approximately 1.0–1.75 times the installation height of the luminaire in front of the mounting point, Type III extends to 1.75–2.75 times the height, Type IV is even further, while Type V forms a basically symmetrical light distribution around the luminaire. These classifications vividly represent the differences in optical angles of the light-emitting element or luminaire in the far field.

[0017] However, existing light-emitting elements often only produce one specific light pattern at the time of manufacture. This is because the freeform surface shape, material refractive index, light-emitting surface size, and lens position of secondary optics are all optimized around a single objective function during the design phase. Once their geometric and optical parameters are fixed, the output far-field light pattern is also fixed. Even adjusting the drive current or duty cycle on the electrical side only changes the output luminous flux, not the angular distribution of the light pattern. Therefore, when the application requires changing the illumination range or adjusting the light distribution, the common practice is to directly replace the light-emitting elements or lenses with different optical angles. This approach results in a large number of product models, increased inventory pressure, and increased complexity in installation and maintenance. Based on this, proposing a solution that can controllably switch between multiple light patterns in a single device has become a pressing technical need for the industry.

[0018] One embodiment of this application provides a light distribution switching method. In this embodiment, the method is applied to a light-emitting device, which includes a first light-emitting unit 2 and a second light-emitting unit 3. The first light-emitting unit 2 is used to form a first target light pattern, and the second light-emitting unit 3 is used to form a second target light pattern. The light intensity distributions of the emitted light from the first light-emitting unit 2 and the second light-emitting unit 3 on the far-field observation plane overlap. The method includes: The first light-emitting unit 2 and the second light-emitting unit 3 are driven, and the contribution of the first light-emitting unit 2 and the second light-emitting unit 3 to the overall light distribution is adjusted by a preset output luminous flux ratio, so as to obtain multiple light patterns including the first target light pattern, the second target light pattern and at least one composite light pattern formed by superposition of the two.

[0019] Specifically, in the above embodiments, the light-emitting device includes a first light-emitting unit 2 and a second light-emitting unit 3. Each light-emitting unit consists of an independent light source and a corresponding lens or other optical components, used to form a specific target light pattern when energized. For example, the first light-emitting unit 2 can be designed to output a Type II light pattern conforming to the IESNA standard, while the second light-emitting unit 3 can form a Type V light pattern. Of course, in different embodiments, the first and second target light patterns can also be replaced with other commonly used light pattern combinations such as Type III and Type IV. This solution is not limited to the selection of specific light patterns, but emphasizes the difference in spatial distribution between the two types of light patterns, thereby providing a basic condition for superposition.

[0020] The two light-emitting units are installed relatively independently, and are designed so that the light intensity distribution output on the far-field observation plane has an overlapping region. The far-field observation plane refers to the area several times the installation height from the luminaire mounting point, where the light intensity distribution tends to stabilize and can serve as a standard reference for light distribution analysis. The overlapping region refers to the area on the light intensity distribution curve of this observation plane where the first target light pattern and the second target light pattern simultaneously have effective light intensity coverage within a certain angle range. This overlapping design allows the light emitted by the two units to linearly superimpose in the overall light distribution, thereby generating a composite light pattern.

[0021] During use, the device illuminates the first light-emitting unit 2 and the second light-emitting unit 3 respectively via a drive circuit, and sets a preset output luminous flux ratio. The preset output luminous flux ratio refers to the ratio of the luminous flux of the two units during electrical driving, such as 1:1.2 or 1:1.6. Under this ratio control, the superposition of the light intensity of the two units in the far field will exhibit different weighted results. In this case, the contribution to the overall light distribution refers to the share of the total light intensity that the first light-emitting unit 2 and the second light-emitting unit 3 each account for when their light intensities are superimposed at the same observation angle. By adjusting the ratio, the coverage and symmetry of the overall light pattern can be continuously changed.

[0022] When the ratio is set to drive only one of them, the corresponding first or second target light pattern can be obtained. When both are lit simultaneously and different ratio values ​​are selected, the overall light distribution on the far-field observation plane appears as a new light pattern formed by the superposition of the two target light patterns, i.e., a composite light pattern. These composite light patterns may correspond to standard light patterns such as Type III and Type IV at different ratios, or they may form transitional light patterns between the two. Therefore, this method can output multiple light patterns in a single device, including the original two target light patterns and at least one composite light pattern formed by their superposition, to meet the lighting needs of different scenarios.

[0023] It should be noted that, in one feasible implementation, the first light-emitting unit 2 and the second light-emitting unit 3 are respectively connected to independent driving channels. Each driving channel includes a constant current source module and an adjustable control module. The constant current source module ensures that the unit receives a stable current during operation, preventing light output distortion due to power supply fluctuations. The adjustable control module can set the output luminous flux of each unit separately through pulse width modulation (PWM), current regulation, or digital interface control. The two driving channels are coordinated by the same controller, which can store preset luminous flux ratios and call the corresponding control parameters during operation to make the first light-emitting unit 2 and the second light-emitting unit 3 emit light according to the required ratio. Through this dual-channel independent driving circuit design, independent control of the light output of the two units can be achieved without changing the hardware structure.

[0024] In another embodiment, the first light-emitting unit 2 and the second light-emitting unit 3 can be connected to the same driving power supply, but an independent current shunt adjustment circuit, such as a programmable current distribution module, is provided at the power supply output terminal, so that the total current of the same power supply can be distributed between the two units according to a preset ratio. This reduces the number of power supplies and enables flexible control over the luminous flux ratio of the two units.

[0025] The circuits described above are already widely used technologies, so they will not be discussed in detail here.

[0026] In a preferred embodiment, the first target light pattern is a Type II light pattern conforming to the IESNA standard, and the second target light pattern is a Type V light pattern conforming to the IESNA standard.

[0027] Specifically, the light pattern classification in the IESNA standard is an industry-standard classification based on the light intensity distribution range and coverage characteristics of luminaires in the far field.

[0028] Type II light patterns are primarily used for road lighting. They are characterized by a longitudinally extending light strip formed directly in front of the luminaire, typically covering an area 1.0 to 1.75 times the installation height, providing good forward illumination in single-lane or two-lane road environments. Using the first light-emitting unit 2 to form a Type II light pattern can meet the lighting needs of road edges or narrow areas.

[0029] Type V light pattern is an axisymmetric light pattern, with its light distribution being basically uniform in the horizontal direction. It is often used for area lighting in squares, intersections, or parks. Its characteristic is the formation of a ring-shaped symmetrical light spot around the luminaire, with an approximately circular coverage area, providing uniform illumination from all directions. Using a second light-emitting unit 3 to form a Type V light pattern can meet the needs of places requiring omnidirectional uniform illuminance.

[0030] By setting two light-emitting units in the same device that can respectively form Type II and Type V light patterns, and combining proportional control and far-field superposition design, not only can the aforementioned two typical light patterns be obtained individually, but composite light patterns including Type III or Type IV can also be generated in between, thereby covering two major application scenarios, road lighting and area lighting, in one device.

[0031] In a preferred embodiment, the preset output luminous flux ratio includes at least one of the following ratios: The output luminous flux ratio of the first light-emitting unit 2 to the second light-emitting unit 3 is 1:0; The ratio of the output luminous flux of the first light-emitting unit 2 to that of the second light-emitting unit 3 is 1:1.2; The output luminous flux ratio of the first light-emitting unit 2 to the second light-emitting unit 3 is 1:1.6; The output luminous flux ratio of the first light-emitting unit 2 to the second light-emitting unit 3 is 1:2.0; The ratio of the output luminous flux of the first light-emitting unit 2 to that of the second light-emitting unit 3 is 0:1.

[0032] First, look at the ray tracing diagram. Figure 4 The coordinate system is defined as follows: the Y-axis represents the vertical direction from bottom to top in the viewpoint, the Z-axis represents the horizontal direction from left to right in the viewpoint, and the X-axis (not shown) is the direction from the observer into the drawing. The light rays in the drawing are the outgoing rays from the emitting units after refraction through their respective lenses. It can be seen that the two sets of light sectors diverge together to the right and forward, and overlap within a certain angular range in space. This overlap does not mean that every ray intersects perfectly in geometric position, but rather that on the angular coordinates of the far-field observation plane, both sets of outgoing rays have non-zero light intensity within the same angular range, thus possessing additivity, laying the foundation for subsequent light distribution superposition and proportional adjustment.

[0033] Next, let's look at the polar coordinate diagram of the light distribution. Figure 5The display shows the light intensity distribution of the same beam on two mutually orthogonal light distribution sections. Line 1 corresponds to the C0–C180 section (a transverse section related to the Z-axis direction, which can be understood as a light distribution slice in the left-right direction, and the curve is approximately symmetrical about the Z-axis), and line 2 corresponds to the C90–C270 section (a longitudinal section related to the Y-axis direction, which can be understood as a light distribution slice in the front and back directions of the road). With the output luminous flux ratio of the first light-emitting unit 2 to the second light-emitting unit 3 being 1:1.2, line 1 is wider and basically symmetrical in the lateral direction, indicating that the entire beam of light is filled by the axisymmetric light distribution corresponding to the second light-emitting unit 3 in the left and right directions. Line 2, on the other hand, shows a significant bulge and elongation in the forward direction towards +Y, with its main energy concentrated in the elevation angle range of approximately 45°–60.5°. This is a typical manifestation of road light distribution with obvious forward projection characteristics. It can be seen that line 2 has a steep rise and peak at the red circle, which meets the requirement of IES Type II to form the main illumination area in the range 1.0–1.75 times the installation height in front. Therefore, under this ratio, the longitudinal section can be interpreted as being dominated by the Type II form, while superimposed with a more balanced lateral component.

[0034] Regarding the preset output luminous flux ratio, it can be 1:0 or 1:1.2 (see the corresponding light pattern diagram). Figure 5 ), 1:1.6 (please refer to the corresponding light pattern diagram) Figure 8 ), 1:2.0 (please refer to the corresponding light pattern diagram) Figure 9 ), 0:1 (please refer to the corresponding light pattern diagram) Figure 7 This can be understood as the proportion of luminous flux contributed by the first luminous unit 2 and the second luminous unit 3 during the same driving period. The more the proportion tilts towards the second luminous unit 3, the wider the line 1 becomes laterally, and the overall distribution tends to be axially symmetrical. The overall light pattern gradually transitions from being dominated by Type II to a wider coverage, approaching the templates of Type III and Type IV. When the ratio is 0:1, it is equivalent to lighting only the second luminous unit 3, which can obtain an axially symmetrical light pattern similar to Type V. Conversely, if it is 1:0, it is equivalent to lighting only the first luminous unit 2, corresponding to Type II. The reason why the ratio of 1:1.2 can still show significant forward projection in line 2 is that the vertical energy distribution of the first luminous unit 2 dominates the 45°–60.5° range, while the second luminous unit 3 mainly provides balanced filling in the left and right directions. Therefore, the superposition of the two has both forward projection and lateral coverage.

[0035] Another embodiment of this application provides a light-emitting device; please refer to [link to relevant documentation]. Figure 2 and Figure 3The device includes a substrate 1, a first light-emitting unit 2, and a second light-emitting unit 3; wherein, the first light-emitting unit 2 includes a first light-emitting source 21 disposed on the substrate 1 and a first lens 22 covering the first light-emitting source 21, and when the first light-emitting source 21 is powered on, it cooperates with the first lens 22 to form a first target light pattern; The second light-emitting unit 3 includes a second light-emitting source 31 disposed on the substrate 1 and a second lens 32 covering the second light-emitting source 31. When the second light-emitting source 31 is powered on, it cooperates with the second lens 32 to form a second target light pattern. The first light source 21 and the second light source 31 are located on the same side of the substrate 1, and the light intensity distribution of the first light source 21 and the second light source 31 on the far-field observation plane overlaps.

[0036] Specifically, substrate 1 serves as the mounting reference and support component for the light-emitting unit, and its form can be a metal heat sink, a ceramic substrate, or a composite material plate with thermal conductivity. Substrate 1 dissipates heat from the light source through its own thermal conductivity, while simultaneously providing stable mechanical support for lens fixation. Multiple mounting positions are provided on one side of substrate 1 to ensure that different light-emitting units have a preset spatial spacing and alignment accuracy.

[0037] The first light-emitting unit 2 includes a first light-emitting source 21 disposed on the substrate 1 and a first lens 22 covering the light-emitting source. The first light-emitting source 21 can be a high-power LED chip or LED package device, such as a 3535 or 5050 package, and its light-emitting surface is usually a rectangular or circular light-emitting window. To ensure the light shaping effect, the first lens 22 is preferably an asymmetric freeform surface lens, whose inner or outer surface is designed with optimized curvature so that the emitted light can meet the distribution characteristics of Type II light pattern in the far field, that is, it has obvious long-range illumination in the forward direction, while the lateral extension is relatively limited.

[0038] The structure of the second light-emitting unit 3 is similar to that of the first light-emitting unit 2, also consisting of a second light-emitting source 31 and a second lens 32 covering it. The second light-emitting source 31 can be of the same or similar type as the first light-emitting source 21, but its corresponding lens is preferably a rotationally symmetric free-form surface structure to form an axisymmetric light distribution close to Type V, that is, the light energy is basically uniformly covered in the surrounding area, thereby achieving a ring illumination effect. The first lens 22 and the second lens 32 differ in shape, curvature and optical design, which is the basis for the two types of units to form different target light patterns in the far field.

[0039] Since the first light source 21 and the second light source 31 are both arranged on the same side of the substrate 1, their light emission directions are roughly consistent. Therefore, the light intensity distribution on the far-field observation plane will have overlapping intervals. The so-called overlapping interval refers to the fact that within a certain angular range, both units contribute light intensity in that angular direction, so the overall light intensity is the superposition of the two. By adjusting the output light flux ratio of the two units, switching and transition between the first target light pattern and the second target light pattern can be achieved, and multiple light patterns, including composite light patterns, can be generated, thus overcoming the limitation that a single lens can only provide fixed light distribution.

[0040] Preferably, the first lens 22 is a freeform lens, and the second lens 32 is a freeform lens.

[0041] Freeform lenses are optical elements whose optical surfaces are not constrained by the geometry of spherical or rotationally symmetric cylindrical surfaces, but are defined and optimized according to specific light distribution objectives through aspherical functions or polynomial functions. Compared to traditional spherical lenses, freeform lenses can impart differentiated refraction or refractive index distributions to light in different directions, thus enabling more flexible control over the angle and intensity distribution of the emitted beam.

[0042] In this device, the first lens 22 adopts a freeform surface structure, which allows the light emitted by the first light source 21 to be directed to meet the forward light distribution requirements of road lighting, such as a Type II light pattern concentrated in the forward projection direction. The difference in curvature of its surface in the longitudinal and lateral directions ensures that the light spot shape extends into the depth of the road while avoiding excessive lateral expansion, thereby highlighting the lighting coverage of local areas.

[0043] The second lens 32 also adopts a freeform surface structure, but its design goal is different, leaning more towards axial symmetry to ensure that light diffuses uniformly in all directions, thus forming a light pattern close to Type V. The freeform surface shape of this lens is closer to a rotationally symmetric design, making the light intensity basically consistent in all directions by refracting the incident light at multiple angles.

[0044] The reason for simultaneously specifying that both are freeform lenses is that only by utilizing the design freedom provided by freeform surfaces can two types of target light patterns, possessing both forward elongation and balanced axisymmetry, be achieved within the same light-emitting device. In other words, this constraint ensures that the solution can accurately achieve the expected optical output without being limited by the light distribution control limitations of traditional spherical lenses.

[0045] Preferably, the shortest interval between the first lens 22 and the second lens 32 is in the range of 20–40 mm. Here, the interval refers to the distance between the outer edges of the lenses or their closest adjacent points after the two lenses are mounted on the substrate 1. This spatial parameter is necessary because the relative arrangement of the lenses directly determines the superposition of their respective light patterns on the far-field observation plane.

[0046] When the spacing is too small, such as less than 20 mm, the optical paths between the two lenses are prone to mutual interference, which may lead to ghosting of light spots, distortion of light patterns, or uneven energy distribution, thus affecting the accurate formation of the target light pattern. Conversely, when the spacing is too large, such as greater than 40 mm, the light spots output by the two lenses are difficult to form a sufficient overlap area in the far field, which is not conducive to achieving smooth light distribution switching through the output light flux ratio, and may even result in the two beams being spatially separated, losing the meaning of superposition control.

[0047] By limiting the spacing to the range of 20–40 mm, sufficient independence between lenses is ensured, near-field optical interference is avoided, and an effective light intensity overlap range is formed in the far field, thus providing conditions for subsequent multi-mode switching.

[0048] In practice, the specific values ​​can be 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm or 40mm, and no specific restrictions are imposed here.

[0049] Optionally, the ratio of the height by which the first lens 22 protrudes from the substrate 1 to the height by which the second lens 32 protrudes from the substrate 1 is 0.6–0.9. In specific implementations, it can be 0.6, 0.7, 0.8, or 0.9, and no specific limitation is made here.

[0050] It should be noted that the height by which the lens protrudes from the substrate 1 refers to the maximum distance from the mounting surface of the lens on the substrate 1 to the top outer surface of the lens. This parameter reflects the overall size and mounting configuration of the lens. By setting the height ratio between 0.6 and 0.9, a reasonable hierarchical relationship can be ensured between the two types of lenses in terms of structure, thereby achieving the desired light distribution effect.

[0051] If the heights of the two lenses are too close (the ratio is close to 1), the first lens 22 and the second lens 32 will be almost on the same plane in space, which will increase the possibility of near-field occlusion, especially in the edge region of the beam, where local shadows or uneven transitions are likely to occur. If the ratio is too low (less than 0.6), it means that the first lens 22 is much smaller than the second lens 32, and the intensity distribution and coverage of the emitted light may be weakened, making it difficult to form a stable first target beam pattern.

[0052] By controlling the height ratio between 0.6 and 0.9, the first lens 22 is ensured to have sufficient optical volume to achieve its target light pattern, while its excessive protrusion is avoided from interfering with the light output path of the second lens 32. The reasonable matching of the two lenses in the depth direction allows the light output of the two units to maintain relative independence in the far field, while having good light intensity matching in the superposition interval, which is conducive to the formation and switching of composite light patterns.

[0053] Preferably, the gap between the light-emitting surface of the first light source 21 and the incident surface of the first lens 22 is 1–2 mm, and the gap between the light-emitting surface of the second light source 31 and the incident surface of the second lens 32 is 1–2 mm.

[0054] Specifically, the gap here refers to the air distance between the light-emitting surface of the light source (usually the light-transmitting encapsulation surface of the LED chip or the surface of the silicone lens) and the inner incident surface of the lens.

[0055] The setting of this parameter directly affects the coupling efficiency and light output distribution. If the gap is less than 1 mm, the light-emitting surface of the light source and the incident surface of the lens are too close, which may lead to increased heat accumulation between them. At the same time, it is easy to cause scratches or uneven bonding during production and assembly, reducing reliability. On the other hand, too small a gap will also weaken the effective refraction path of the lens for light, resulting in incomplete beam shaping and light distribution deviating from the target.

[0056] Conversely, when the gap is greater than 2 mm, the outgoing light will experience significant spot diffusion and refraction deviation before entering the lens, and some edge rays may not even be effectively collected by the lens, resulting in a decrease in optical efficiency. At the same time, an excessively large air layer may also introduce stray light, causing uneven energy distribution or blurred edges in the far-field beam pattern.

[0057] Limiting the gap to 1–2 mm ensures that the lens adequately shapes the light emitted from the light source, while also providing good operability in the assembly process and allowing sufficient space for heat dissipation and structural tolerances. This setting achieves a balance between optical performance, heat dissipation performance, and assembly process, thereby ensuring that the first and second target light patterns can be generated stably and repeatably.

[0058] In practice, the gap (between the first light source 21 and the first lens 22, or between the second light source 31 and the second lens 32) can be 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm or 2mm, and no specific limit is imposed here.

[0059] Optionally, the first light source 21 and the second light source 31 are configured to be driven separately, meaning each has an independent current control path. This design aims to ensure that the output luminous flux of both can be adjusted independently, thereby meeting the requirements for switching the light distribution ratio.

[0060] In practice, the following approach can be adopted: each light source is connected to its corresponding constant current driving circuit. The constant current driving circuit can be set independently or divided into independent driving channels within the same driving module. For example, the first light source 21 is connected to the first constant current source channel, and the second light source 31 is connected to the second constant current source channel; the two channels are mutually insulated. By adjusting the input to the driving circuit through an external controller, the output current of the first and second channels can be changed respectively, thereby achieving proportional control of the luminous flux of the first light source 21 and the second light source 31.

[0061] In a preferred embodiment, the controller can employ pulse width modulation (PWM), digital-to-analog converter current regulation (DAC), or a multi-channel output method with a constant current drive chip, enabling the first light source 21 and the second light source 31 to be lit individually or simultaneously, with their brightness ratio flexibly adjusted according to a preset curve or preset value. Thus, during device operation, the user does not need to replace components or optical parts; switching between Type II, Type V, and composite light patterns can be achieved solely through the control of the drive circuit.

[0062] This separately driven circuit design ensures the independence and flexibility of the device in optical control, while also avoiding electrical coupling interference between the two light sources, thus improving the reliability of the system and the repeatability of light distribution control.

[0063] Optionally, there are multiple first light-emitting units 2 and multiple second light-emitting units 3. Multiple first light-emitting units 2 are arranged in a row on the substrate 1 along a first direction (usually the long side direction of the lamp or the road extension direction) to form a first column 4. Multiple second light-emitting units 3 are arranged in a row on the substrate 1 along the first direction to form a second column 5. The first column 4 and the second column 5 are arranged in parallel on the substrate 1 and spaced apart from each other.

[0064] The purpose of this arrangement is to ensure the uniformity and continuity of the overall light pattern in a wide range of application scenarios. When only a single first unit and a single second unit are used, the light intensity distribution in the far field may appear locally concentrated, easily resulting in bright spots or dark areas. However, by arranging multiple units into an array, the light spots can be superimposed and smoothly transitioned in the vertical direction, thereby forming a continuous and consistent light distribution effect in road lighting or large-area scenarios.

[0065] Meanwhile, the parallel arrangement of columns 4 and 5 ensures a regular superposition of the two light patterns in the lateral direction. By controlling the spacing between columns, excessive interference between different units is avoided, while ensuring that the overlapping area of ​​the two light patterns covers the entire illumination strip on the far-field observation plane. This allows for simultaneous transitions and switching of light patterns in both the road width and depth directions when adjusting the luminous flux ratio, ensuring consistency and controllability of optical performance.

[0066] In other words, this multi-unit array arrangement allows the device to go beyond the switching of light patterns from a single point light source, and extend to the overall light distribution switching of a multi-point array, thereby better meeting the requirements of actual lighting for uniformity, coverage and light pattern flexibility.

[0067] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for switching light distribution, characterized in that, The light distribution switching method is applied to a light-emitting device, which includes a first light-emitting unit and a second light-emitting unit. The first light-emitting unit is used to form a first target light pattern, and the second light-emitting unit is used to form a second target light pattern. The light intensity distribution of the light emitted by the first light-emitting unit and the second light-emitting unit on the far-field observation plane has an overlapping range. The method includes: The first light-emitting unit and the second light-emitting unit are driven, and the contribution of the first light-emitting unit and the second light-emitting unit to the overall light distribution is adjusted by a preset output luminous flux ratio, so as to obtain multiple light patterns including the first target light pattern, the second target light pattern and at least one composite light pattern formed by superposition of the two.

2. The light distribution switching method according to claim 1, characterized in that, The first target light pattern is a Type II light pattern conforming to the IESNA standard, and the second target light pattern is a Type V light pattern conforming to the IESNA standard.

3. The light distribution switching method according to claim 2, characterized in that, The preset output luminous flux ratio includes at least one of the following ratios: The output luminous flux ratio of the first light-emitting unit to the second light-emitting unit is 1:0; The output luminous flux ratio between the first light-emitting unit and the second light-emitting unit is 1:1.2; The output luminous flux ratio of the first light-emitting unit to the second light-emitting unit is 1:1.6; The output luminous flux ratio of the first light-emitting unit to the second light-emitting unit is 1:2.0; The ratio of the output luminous flux of the first light-emitting unit to that of the second light-emitting unit is 0:

1.

4. A light-emitting device, characterized in that, The light-emitting device employs the light distribution switching method as described in claims 1 to 3, and the light-emitting device comprises: substrate; The first light-emitting unit includes a first light-emitting source disposed on the substrate and a first lens covering the first light-emitting source. When the first light-emitting source is powered on, it cooperates with the first lens to form a first target light pattern. The second light-emitting unit includes a second light-emitting source disposed on the substrate and a second lens covering the second light-emitting source. When the second light-emitting source is powered on, it cooperates with the second lens to form a second target light pattern. The first light source and the second light source are located on the same side of the substrate, and the light intensity distribution of the first light source and the second light source on the far-field observation plane overlaps.

5. The light-emitting device according to claim 4, characterized in that, The first lens is a freeform lens, and the second lens is a freeform lens.

6. The light-emitting device according to claim 4, characterized in that, The minimum distance between the first lens and the second lens ranges from 20 to 40 mm.

7. The light-emitting device according to claim 4, characterized in that, The ratio of the height by which the first lens protrudes from the substrate to the height by which the second lens protrudes from the substrate is 0.6–0.

9.

8. The light-emitting device according to claim 4, characterized in that, The gap between the light-emitting surface of the first light source and the incident surface of the first lens is 1–2 mm, and the gap between the light-emitting surface of the second light source and the incident surface of the second lens is 1–2 mm.

9. The light-emitting device according to claim 4, characterized in that, The first light source and the second light source are configured to be driven separately.

10. The light-emitting device according to claim 4, characterized in that, The number of the first light-emitting unit and the second light-emitting unit are both multiple. The multiple first light-emitting units are arranged in a column along a first direction on the substrate to form a first column, and the multiple second light-emitting units are arranged in a column along the first direction on the substrate to form a second column. The first column and the second column are arranged in parallel on the substrate and spaced apart from each other.

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