Low-position polarized lighting lens for tunnel and light distribution design method

Abstract

The low-position polarized lighting lens comprises a light source cavity, an inner curved surface and an outer curved surface, the light source cavity is an inwards-concave cavity, the inner curved surface is an incident surface, the outer curved surface is a light-emitting surface, and the inner curved surface and the outer curved surface are both asymmetric free-form surfaces. Light intensity mapping is performed by combining near-field light intensity energy distribution of the LED light source, and distribution coordinate points of inner and outer curved surfaces of the lens are determined by using a ray tracing principle; starting from the relation between luminous flux and light intensity, after the near-field Lambert light pattern of the LED lamp bead is refracted and reflected through the two free-form surfaces of the lens, target energy space distribution is formed, the designed lens is tested and simulated, and it is proved that relevant effective parameters of the tunnel road illumination standard are met and are all higher than standard requirements. The tunnel low-position lighting requirement is met to the maximum extent.

Description

Technical Field

[0001] The present invention relates to the technical field of LED semiconductor lighting applications, and in particular to a low-position polarized lighting lens for tunnels and a light distribution design method. Background Art

[0002] Compared with traditional tunnel lighting and lamp layout, LED light source lamps have the advantages of low power consumption, high light efficiency, long life, green environmental protection, and controllable light distribution, becoming the mainstream choice of the industry. With the rapid development of more than ten years, LED lighting has gradually been popularized in various fields of lighting.

[0003] The light type of LED light source is Lambertian distribution, which cannot be directly applied to road lighting or the lighting effect is poor, so secondary optical design is required. According to the near-field light type of LED light source, different reflective or refractive lens devices are designed to convert the Lambertian distribution of LED light source into multi-type distribution suitable for different scenes in response to different packaging forms of LED light sources and different tunnel road requirements. This process is called secondary optical design. Changing the distribution form of LED light source through secondary optical design plays a vital role in the field of tunnel lighting.

[0004] At present, there are many lenses designed for secondary optics of LED light sources, most of which are designed based on illuminance distribution. The ideal state of illuminance distribution is that the light intensity remains consistent in different areas. Although the illuminance distribution can be designed to be relatively uniform, in scenes such as tunnels, the human eye still sees a difference in light and dark, and the visual effect is average. In addition, for tunnel lighting, the Ministry of Transport standard "JTG / T D70 / 2-01-2014)" has clear requirements on brightness. At the same time, glare is also an important factor affecting tunnel driving safety. Based on this, a low-position polarized lighting lens and a light distribution design method for tunnels are proposed. Based on light intensity distribution rather than illuminance distribution, it can effectively improve the application and safety requirements of tunnel lighting scenes. Summary of the invention

[0005] To solve the above problems, the present invention provides a low-position polarized lighting lens for tunnels and a light distribution design method, wherein both the inner and outer curved surfaces are asymmetric free-form surfaces, and the coordinate points of the inner and outer curved surfaces are obtained by: according to the light intensity distribution requirements of the target road lighting surface, the light intensity mapping is performed in combination with the near-field light intensity energy distribution of the LED light source, and the distribution coordinate points of the inner and outer curved surfaces of the lens are calculated using the ray tracing principle. The lens designed by the present invention can effectively improve the lighting brightness effect in the tunnel, reduce glare, and effectively improve driving safety.

[0006] The technical solution adopted by the present invention is: The present invention provides a low-position polarized lighting lens for tunnels, comprising a light source cavity, an inner curved surface and an outer curved surface. The light source cavity is an inner concave cavity for accommodating a light source, the inner curved surface is an incident surface, and the outer curved surface is a light emitting surface. Both the inner curved surface and the outer curved surface are asymmetric free-form surfaces. According to the light intensity distribution requirements of a target road lighting surface and the near-field light intensity energy distribution of the light source, light intensity mapping is performed in combination with the near-field light intensity energy distribution of the light source, and the distribution coordinate points of the inner and outer curved surfaces of the lens are determined by using the principle of ray tracing.

[0007] Furthermore, the lens may be in the form of a single lens or a combination of multiple lenses.

[0008] Furthermore, the size and depth of the light source cavity can be adjusted according to the light source size of the LED.

[0009] The present invention also provides a light distribution design method based on the above-mentioned low-position polarized lighting lens for tunnels, comprising the following steps: Step S1: Determine the lighting parameter requirements for the target road illumination surface according to the tunnel low-level lighting requirements and relevant specifications and standards, where the lighting parameters include average brightness, illumination, and glare; Step S2: performing light intensity mapping based on the light intensity distribution requirements of the target road lighting surface and combining the near-field light intensity energy distribution of the LED light source; Step S3: Calculate the basic distribution of coordinate points on the inner and outer surfaces of the lens using the principle of ray tracing; Step S4: Import the obtained coordinate points into the modeling software for 3D modeling to obtain the initial model of the lens. According to the law of refraction and reflection in geometric optics, light passing through the initial model of the lens will be refracted and reflected. According to the effect of light emission, the curvature of the lens surface is adjusted; Step S5: According to the lighting requirements of the target road, the lens model is optimized again to determine the final model of the lens.

[0010] Specifically, in step S5, the optimization model adopts a free surface stepwise optimization method to establish a tunnel lighting simulation model, analyze the lighting effect, perform stepwise optimization, and compare the optimization results with the target tunnel lighting requirements to obtain the optimal data.

[0011] Furthermore, according to the law of conservation of energy, the luminous flux in the near-field angle of the LED light source is refracted and reflected twice by the free-form surface of the lens, and then the light intensity is redistributed to form a new light distribution design. The luminous flux in the near-field angle of the light source is equal to the luminous flux in the diffusion angle after refraction and reflection by the lens.

[0012] Beneficial effects of the present invention: The lens and light distribution design method of the present invention are designed based on the near-field light intensity distribution of LEDs for secondary optical lens and light distribution. Starting from the relationship between luminous flux and light intensity, the method refracts and reflects the near-field Lambertian light pattern of LED lamp beads through two free-form surfaces of the lens to form a target energy spatial distribution and a target light distribution form. The object designed according to this method has been tested and simulated, proving that the lens meets the tunnel road lighting standards, and the effective parameters such as brightness, uniformity, and glare are all higher than the standard requirements, which can meet the low-level lighting requirements of tunnels to the maximum extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a first stereoscopic view of the tunnel low-position lighting lens of the present invention; Figure 2 It is a second stereoscopic view of the low-position tunnel lighting lens of the present invention.

[0014] In the figure, 1, inner curved surface, 2, outer curved surface, 3, base.

[0015] Figure 3 This is the layout diagram of the target tunnel road surface and lighting.

[0016] Figure 4 This is the lens light distribution curve diagram.

[0017] Figure 5 This is the tunnel lighting simulation result diagram. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and a preferred implementation manner. Example

[0019] refer to Figure 1-2 This embodiment provides a low-position polarized lighting lens for tunnels, including a lens base 3, a light source cavity, an inner curved surface 1 and an outer curved surface 2. The light source cavity is an inner concave cavity for accommodating a light source. The size and depth of the light source cavity can be adjusted according to the size of the LED light source. The inner curved surface 1 is the incident surface, and the outer curved surface 2 is the light emitting surface. Both the inner curved surface 1 and the outer curved surface 2 are asymmetric free-form surfaces. According to the light intensity distribution requirements of the target road lighting surface and the near-field light intensity energy distribution of the light source, the light intensity mapping is performed in combination with the near-field light intensity energy distribution of the light source, and the distribution coordinate points of the inner and outer curved surfaces of the lens are determined using the principle of ray tracing; the lens can be in the form of a single or multiple combined modules.

[0020] Specifically, the light source cavity is determined according to the size of the LED lamp beads. In this example, a 3030 light source is selected.

[0021] refer to Figure 3According to the requirements of tunnel road lighting, the tunnel lamp installation height is 3 meters, the road width is 8 meters, the lighting is arranged in two directions, and the unidirectional polarized light design is adopted. The average brightness Lav of the tunnel entrance section is not less than 78cd / m², and the average brightness Lav of the basic section is not less than 2cd / m². Example

[0022] Based on the above embodiments, this embodiment provides a light distribution design method for a low-position polarized lighting lens for a tunnel, 4. comprising the following steps: Step S1: According to the low-level lighting requirements of the tunnel and the requirements of relevant specifications and standards, the lighting parameter requirements required for the target road illumination surface are determined. The lighting parameters include average brightness, illuminance and glare. In this embodiment, the average brightness of the tunnel entrance section Lav ≥ 78cd / m², the average brightness of the basic section Lav is not less than 2cd / m², the average illuminance ≥ 30lx, and the glare ≤ 10.

[0023] Step S2: According to the light intensity distribution requirements of the target road lighting surface, specifically including the average brightness Lav, the overall uniformity U0 of the lighting system, the local uniformity Ul of the lighting system and the average illuminance Eav, the light intensity mapping is performed in combination with the near-field light intensity energy distribution of the LED light source; Step S3: Calculate the basic distribution of coordinate points on the inner and outer surfaces of the lens using the principle of ray tracing. Specifically, professional optical design software such as Trace pro and Light Tools can be used to simulate the design. Trace pro and Light Tools support complex ray tracing functions, and the basic coordinate data of the inner and outer lenses can be extracted from the simulation results. Step S4: Import the obtained coordinate points into SolidWorks for 3D modeling to obtain an initial lens model. According to the law of refraction and reflection in geometric optics, the light is refracted and reflected after passing through the initial lens model. According to the light output effect, the curvature of the lens surface is adjusted; Step S5: Optimize the lens model according to the lighting requirements of the target road to determine the final model of the lens.

[0024] Specifically, in step S5, the optimization model adopts the free surface step-by-step optimization method to establish a tunnel lighting simulation model, analyze the lighting effect, and perform step-by-step optimization. The optimization results are compared with the target tunnel lighting requirements to obtain the optimal data and confirm the parts.

[0025] Furthermore, according to the law of conservation of energy, the luminous flux within the near-field angle of the LED light source is refracted and reflected twice by the free-form surface of the lens, and the light intensity is redistributed to form a new light spatial distribution. The luminous flux within the near-field angle of the light source and the luminous flux within the diffusion angle after refraction and reflection by the lens are constant, ensuring a more uniform light distribution in the lighting area.

[0026] refer to Figure 4 This figure is the light distribution curve of the LED lamp, that is, the spatial distribution of the light of the lamp. The 90-90° direction is the horizontal direction of the tunnel road, that is, parallel to the driving direction. The light distribution angle in this direction is large and the light intensity is low, which is beneficial to improve the uniformity of the tunnel road surface and reduce the contrast of the lighting space environment, reduce the glare index, and improve the driving safety of the driver; the 0-180° direction is the vertical road direction. The luminous angle in this direction is small, the polarization is large, and the light intensity is large. By adjusting the installation angle and position, a large-angle and large-area lighting effect of the vertical road surface can be achieved.

[0027] refer to Figure 5 This figure is an example simulation data. Through the lamp designed with this lens, the simulation effect shows that the average luminance, that is, the average brightness Lav is 92cd / m 2 , meeting or exceeding the target brightness requirement at the tunnel entrance (≥78cd / m 2 ).

[0028] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications are also within the protection scope of the present invention.

Claims

1. A low-position polarized light illumination lens for a tunnel, comprising a light source cavity, an inner curved surface (1) and an outer curved surface (2), wherein the light source cavity is an inner concave cavity for accommodating a light source, the inner curved surface (1) is an incident surface, and the outer curved surface (2) is a light emitting surface, characterized in that: The inner curved surface (1) and the outer curved surface (2) are both asymmetric free-form surfaces. According to the light intensity distribution requirements of the target road lighting surface and the near-field light intensity energy distribution of the light source, light intensity mapping is performed in combination with the near-field light intensity energy distribution of the light source, and the distribution coordinate points of the inner and outer curved surfaces of the lens are determined using the ray tracing principle.

2. A low-position polarized lighting lens for tunnels according to claim 1, characterized in that: The lens can be in the form of a single lens or a combination of multiple lenses.

3. The low-position polarized lighting lens for tunnels according to claim 1, characterized in that: The light source cavity can be adjusted in size and depth according to the light source size of the LED.

4. A light distribution design method for a low-position polarized lighting lens for a tunnel based on claim 1, characterized in that: The steps include: Step S1: Determine the lighting parameter requirements for the target road illumination surface according to the tunnel low-level lighting requirements and relevant specifications and standards, where the lighting parameters include average brightness, illumination, and glare; Step S2: performing light intensity mapping based on the light intensity distribution requirements of the target road lighting surface and combining the near-field light intensity energy distribution of the LED light source; Step S3: Calculate the basic distribution of coordinate points on the inner and outer surfaces of the lens using the principle of ray tracing; Step S4: Import the obtained coordinate points into the modeling software for 3D modeling to obtain the initial model of the lens. According to the law of refraction and reflection in geometric optics, light passing through the initial model of the lens will be refracted and reflected. According to the effect of light emission, the curvature of the lens surface is adjusted; Step S5: According to the lighting requirements of the target road, the lens model is optimized again to determine the final model of the lens.

5. The method for designing light distribution of a low-position polarized lighting lens for a tunnel according to claim 4, characterized in that: In step S5, the optimization model adopts the free surface step-by-step optimization method to establish a tunnel lighting simulation model, analyze the lighting effect, and perform step-by-step optimization. The optimization results are compared with the target tunnel lighting requirements to obtain the optimal data.

6. The method for designing light distribution of a low-position polarized light illumination lens for a tunnel according to claim 4, characterized in that Specifically, according to the law of conservation of energy, the luminous flux in the near-field angle of the LED light source is refracted and reflected twice by the free-form surface of the lens, and the light intensity is redistributed to form a new light spatial distribution. The luminous flux in the near-field angle of the light source is equal to the luminous flux in the diffusion angle after refraction and reflection by the lens.

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