Projection light cone structure and projection device

Abstract

The utility model discloses a projection light cone structure and projection equipment, wherein the projection light cone structure increases the folding structure through the light entrance face of light cone, carries out twice reflection through the first incidence surface and the second incidence surface of the intercalation angle, and can change the slope of two incidence surfaces to adjust the reflection angle of light, realizes the optimization of the illumination distribution of light, and expands the adjustment range of light exit angle. Thus effectively reduce the optical expansion of light source from the light cone exit, reduce the luminous flux loss, improve the optical utilization.

Description

Technical Field

[0001] This utility model relates to the field of projection technology, and in particular to a projection light cone structure and projection device. Background Technology

[0002] Currently, the projection principle of LCD projectors on the market is as follows: the light emitted by the LED passes through a light cone for focusing and homogenizing, a Fresnel lens for collimation, a liquid crystal display chip, a field lens to reduce the incident area of ​​the light, and finally the lens images the light onto the projection screen. Due to the Lambertian radiation characteristics of the light source, the light divergence angle is too large. The single tilted surface of the traditional light cone is difficult to effectively constrain the light emission angle, resulting in a large amount of light exceeding the receiving range of subsequent optical components, and a serious loss of luminous flux. Utility Model Content

[0003] The present invention provides a projection light cone structure and projection device, which aims to solve the problem of light flux loss caused by the difficulty of effectively constraining the light emission angle due to the single inclined surface of the traditional light cone under the prior art.

[0004] In a first aspect, this utility model provides a projection light cone structure, including a light cone body, the light cone body defining a central optical axis, the light cone body including an incident end, an exit end, and a folding structure, the light cone body being a hollow trapezoidal truncated cone extending from the incident end to the exit end, the folding structure being disposed on the inner sidewall of the light cone body, the folding structure including a first incident surface and a second incident surface, an angle being provided between the first incident surface and the second incident surface, the first incident surface being disposed close to the incident end; wherein, at least a portion of the light rays are reflected sequentially by the first incident surface and the second incident surface and then deflected toward the central optical axis before exiting.

[0005] In the projection light cone structure provided by this utility model, the light cone body further includes a light source base surface. The light source base surface is located on the side of the incident end away from the exit end. A first tilt angle θ1 is provided between the first incident surface and the light source base surface, and a second tilt angle θ2 is provided between the second incident surface and the light source base surface. The first tilt angle θ1 and the second tilt angle θ2 satisfy: θ2<θ1<θ2+10°.

[0006] In the projection light cone structure provided by this utility model, the light cone body further defines an incident loop at the incident end. The distance from the incident loop to the central optical axis is denoted as the first distance a. A folded loop is defined at the connection between the first incident surface and the second incident surface. The distance from the folded loop to the central optical axis is denoted as the second distance b. The first distance a and the second distance b satisfy: a <b<2a。

[0007] The projection light cone structure provided by this utility model also includes a synchronization rod. The distance between the folded loop and the base surface of the light source is denoted as the first height H1. The first height H1 satisfies: 3mm≤H1≤10mm.

[0008] In the projection light cone structure provided by this utility model, the first incident surface is a specular reflection layer, and the second incident surface is a diffuse reflection coating.

[0009] In the projection light cone structure provided by this utility model, the folding structure is integrally formed by stamping and bending.

[0010] In the projection light cone structure provided by this utility model, the light cone body is spliced ​​together from a first light cone and a second light cone. The first light cone and the second light cone are hollow trapezoidal truncated cones. The first incident surface is located on the first light cone, and the second incident surface is located on the second light cone.

[0011] In the projection light cone structure provided by this utility model, the light cone body further includes a light leakage prevention structure, which is disposed at the connection between the first incident surface and the second incident surface.

[0012] In the projection light cone structure provided by this utility model, the light leakage prevention structure is a black light-shielding strip, which is embedded at the connection between the first incident surface and the second incident surface.

[0013] Secondly, this utility model provides a projection device, including the above-mentioned projection light cone structure.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] Compared to existing technologies, this invention optimizes the illuminance distribution and expands the adjustment range of the light emission angle by adding a folded structure to the incident surface of the light cone and performing two reflections through a first and a second incident surface with an included angle. Furthermore, the slope of the two incident surfaces can be changed to adjust the reflection angle. This effectively reduces the optical spread of the light source as it exits the light cone, lowers luminous flux loss, and improves optical utilization. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, 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.

[0017] Figure 1 This is a schematic diagram of the projection light cone structure in the prior art;

[0018] Figure 2 This is a schematic diagram of the projection light cone structure according to an embodiment of the present invention;

[0019] Figure 3 The projection principle of the projector used in the projection cone structure of this utility model embodiment;

[0020] Figure 4 A simulation diagram of the luminous flux of a projector using a projection light cone structure based on existing technology;

[0021] Figure 5 A simulation diagram of the luminous flux of a projector using the projection light cone structure of this embodiment;

[0022] Figure 6 A simulation diagram of the image uniformity of a projector using a projection cone structure based on existing technology;

[0023] Figure 7 This is a simulation diagram of the image uniformity of a projector using the projection light cone structure of this utility model embodiment.

[0024] 10. LED light source; 20. Light cone body; 21. Exit end; 22. Folded structure; 221. First incident surface; 222. Second incident surface; 23. Incident end; 30. Fresnel lens; 40. Liquid crystal display chip; 50. Field lens. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0027] This invention provides a projection light cone structure, aiming to solve the problem of luminous flux loss caused by the inability of the single inclined surface of a traditional light cone to effectively constrain the light emission angle. (Refer to...) Figures 1 to 7The projection light cone structure includes a light cone body 20, which defines a central optical axis. The light cone body 20 includes an incident end 23, an exit end 21, and a folding structure 22. The light cone body 20 is a hollow trapezoidal frustum extending from the incident end 23 to the exit end 21. The folding structure 22 is disposed on the inner sidewall of the light cone body 20. The folding structure 22 includes a first incident surface 221 and a second incident surface 222, with an included angle between the first incident surface 221 and the second incident surface 222. The first incident surface 221 is disposed close to the incident end 23. At least a portion of the light rays are reflected sequentially by the first incident surface 221 and the second incident surface 222 and then deflected towards the central optical axis before exiting. The light cone structure of the present invention includes a hollow trapezoidal frustum light cone body 20. The light cone body 20 is composed of an incident end 23, an exit end 21, and a folding structure 22 located on the inner sidewall. Specifically, the light cone body 20 extends along the central optical axis from the incident end 23 to the exit end 21. The light cone is trapezoidal in shape, with unequal dimensions at the incident end 23 and the exit end 21, exhibiting a certain taper. This trapezoidal structure effectively guides light rays, gradually extending them from the incident end 23 to the exit end 21, while reducing the amount of light propagation and improving the utilization efficiency of the optical system. The inner side of the light cone body 20 is provided with a folding structure 22, which includes two reflecting surfaces: a first incident surface 221 and a second incident surface 222. These two incident surfaces form a certain angle, with the first incident surface 221 positioned closer to the incident end 23. Light rays first enter the light cone through the first incident surface 221, then are reflected by the second incident surface 222, and finally deflect towards the central optical axis and exit from the exit end 21. Through the design of the folding structure 22, the direction and angle of light propagation can be adjusted after two reflections, thereby effectively controlling the exit angle of the light rays and reducing light propagation and leakage. Furthermore, the light cone incident surface and folding surface design of this invention offer significant flexibility. Compared to conventional light cones, the addition of the folding structure 22 increases the degree of freedom in adjusting the light cone, allowing for optimization of the tilt angle of the light cone and the range of light emission angles. By appropriately designing the folding angle, the light emission angle can be precisely controlled, reducing the optical spread of the light source and making the light more concentrated, thus reducing light spillover.

[0028] Compared to existing technologies, this invention adds a folded structure 22 to the incident surface of the light cone, enabling double reflection through a first incident surface 221 and a second incident surface 222 with an included angle. The reflection angle of the light can be adjusted by changing the slopes of the two incident surfaces, thus optimizing the illuminance distribution and expanding the adjustment range of the light emission angle. This effectively reduces the optical spread of the light source as it exits the light cone, lowers luminous flux loss, and improves optical utilization.

[0029] Furthermore, referring to Figure 2 The light cone body 20 further includes a light source base surface, which is provided on the side of the incident end 23 away from the exit end 21. A first inclination angle θ1 is provided between the first incident surface 221 and the light source base surface, and a second inclination angle θ2 is provided between the second incident surface 222 and the light source base surface. Among them, the first inclination angle θ1 and the second inclination angle θ2 satisfy: θ2 < θ1 < θ2 + 10°. In an embodiment of the present invention, a light source base surface is provided at the incident end 23 of the light cone body 20. This light source base surface is located on the side of the incident end 23 away from the exit end 21 and serves as a support surface for the light source. Related to the light source base surface are two incident surfaces, the first incident surface 221 and the second incident surface 222, which respectively form a certain inclination angle with the light source base surface. These two inclination angles (the first inclination angle θ1 and the second inclination angle θ2) are respectively the angles formed between the first incident surface 221 and the second incident surface 222 and the light source base surface. Among them, θ1 and θ2 satisfy the relationship:

[0030] θ2 < θ1 < θ2 + 10°

[0031] This means that the second inclination angle (θ2) is smaller than the first inclination angle (θ1), and there is a small angular difference between the two. Through this design, after the light is reflected by the first incident surface 221 and the second incident surface 222, it will deflect towards the central optical axis, thereby achieving the directional control of the light and minimizing the optical expansion.

[0032] Furthermore, referring to Figure 2 At the incident end 23 of the light cone body 20, an incident loop is further defined. The distance from the incident loop to the central optical axis is denoted as the first distance a. A folding loop is defined at the connection between the first incident surface 221 and the second incident surface 222. The distance from the folding loop to the central optical axis is denoted as the second distance b. Among them, the first distance a and the second distance b satisfy: a < b < 2a. An incident loop is provided at the incident end 23 of the light cone body 20. The setting of the incident loop helps to guide the light into the light cone system, ensuring that when the light reaches the first incident surface 221 from the light source, it can be incident at a predetermined angle, reducing unnecessary scattering and loss. The distance from the incident loop to the central optical axis is defined as the first distance a, and the magnitude of this distance a plays an important role in the reflection path of the light. Inside the light cone body 20, a folding loop is also defined at the connection between the first incident surface 221 and the second incident surface 222. The setting position of the folding loop is between the first incident surface 221 and the second incident surface 222. The first distance a and the second distance b satisfy the following relationship:

[0033] a < b < 2a

[0034] This relationship ensures that the folded loop is positioned appropriately, allowing light to exit within a relatively concentrated area after two reflections. Specifically, a smaller distance 'a' indicates that the incident light is closer to the center of the light cone, while a larger distance 'b' of the folded loop means that the light will spread appropriately after reflection, resulting in a more uniform light distribution and avoiding excessive concentration or scattering. Through this design, the folded structure 22 can optimize the light reflection path while increasing the utilization rate of the optical system. The relationship between the second distance 'b' and the first distance 'a' not only controls the light reflection angle but also effectively reduces optical spread, enabling the projection system to achieve higher light efficiency and a more uniform illuminance distribution on the output beam.

[0035] Furthermore, referring to Figure 2 The distance between the folded loop and the base surface of the light source is denoted as the first height H1, which satisfies the condition: 3mm ≤ H1 ≤ 10mm. At the incident end 23 of the light cone, the distance from the folded loop to the base surface of the light source is defined as the first height H1. The value of this height H1 is limited to between 3mm and 10mm, i.e., it satisfies:

[0036] 3mm≤H1≤10mm

[0037] The design of the initial height H1 not only affects the overall structure of the light cone but also directly relates to the emission angle and illuminance distribution after light reflection. If the initial height H1 is too small, the reflection angle of the folded ring will be too large, potentially causing light to concentrate in a small area and affecting the uniformity of the image. Conversely, if the initial height H1 is too large, it may lead to excessive light diffusion, increasing optical loss. Therefore, an appropriate height range, i.e., 3mm to 10mm, ensures proper reflection and emission of light after passing through the folded surface, achieving the goal of optimizing light efficiency.

[0038] Reference Figures 4 to 7 Simulation data shows that the light cone structure of this invention significantly improves luminous flux and uniformity. In traditional light cone designs, light often exhibits excessive divergence and excessive darkness around the edges. However, with the design of this invention, luminous flux is increased by approximately 13%, and uniformity is improved by approximately 4%. This optimization not only improves the projection effect but also avoids problems such as light overflow, thus enhancing the user's visual experience.

[0039] In one embodiment, the light cone body 20 further includes a light leakage prevention structure (not shown in the figure), which is located at the connection between the first incident surface 221 and the second incident surface 222. The light leakage prevention structure is designed to be located at the connection between the first incident surface 221 and the second incident surface 222. The core purpose of this design is to prevent light leakage when light enters the light cone body 20 due to poor splicing or folding surface precision issues. Light leakage not only reduces light efficiency but also affects the uniformity of the projected image, especially when the light source intensity is high or the light reflection angle is wide, where the light leakage problem is particularly serious. Specific implementations of the light leakage prevention structure can be achieved by setting a sealing strip, using optical absorbing materials, or adding a small light-blocking ring to the structural design at the connection. These methods effectively reduce light leakage, thereby improving the overall light efficiency and uniformity of the light cone structure. This light leakage prevention structure does not significantly increase the complexity of the light cone; on the contrary, it enhances the effective utilization of light, making the projected image brighter and more uniform. To ensure its leak-proof effect, materials with high optical absorption properties or optical materials with good sealing performance are usually selected. Common leak-proof materials include black coating materials, light-absorbing materials, or specific types of foam materials. These materials can effectively absorb leaked light and prevent it from entering the outside of the light cone, thereby improving light efficiency.

[0040] In one embodiment, reference is made to Figure 2 The light cone body 20 is composed of a first light cone and a second light cone, both of which are hollow trapezoidal frustums. The first incident surface 221 is located on the first light cone, and the second incident surface 222 is located on the second light cone. The first and second light cones are hollow trapezoidal frustums, with the first incident surface 221 located on the first light cone and the second incident surface 222 located on the second light cone. The first and second light cones are joined to form a single integrated structure. This design not only increases the structural strength of the light cone but also provides greater design freedom. The advantage of the joined structure is that the optical effect can be further optimized by selecting different materials and adjusting the geometric parameters and folding angles of each light cone. Furthermore, the joined design provides flexibility for production and processing, reducing manufacturing difficulty and cost while ensuring optical performance. Through the joining method, the first and second light cones can be made of different materials, further improving the overall optical performance.

[0041] Furthermore, referring to Figure 2In actual production, tolerance control at the splicing points is crucial. Due to the complexity of the light cone structure, slight deformations or loose joints often occur at the splicing points, which can lead to light leakage. Therefore, strict tolerance control methods are required at the splicing points of the light cone body 20 to ensure precise alignment of each splicing part and avoid excessive gaps or poor contact at the joints. To achieve this goal, high-precision molds and positioning technologies can be used to ensure the accuracy of the splicing parts. During production, every detail of the splicing area must be strictly controlled, such as the flatness of the mating surfaces, the direction of force applied during splicing, and the splicing sequence, all of which require fine adjustment. In addition, the design of the anti-leakage structure can be combined with the bending process of the light cone to further ensure the sealing of the connection.

[0042] Furthermore, the light leakage prevention structure is a black light-shielding strip (not shown in the figure), which is embedded at the connection between the first incident surface 221 and the second incident surface 222. The black light-shielding strip is typically made of a highly light-absorbing material, such as black rubber or polymer materials, which can reduce reflection and absorb light, thereby preventing leakage. The embedded design of the black light-shielding strip ensures a tight fit with the light cone body 20, not only improving the light leakage prevention effect but also optimizing the structural stability. This embedding method ensures a smooth transition between the light-shielding strip and the splicing surface of the light cone, avoiding protruding seams or structural defects, thus reducing the risk of light leakage. Specifically, simulation experiments show that with the black light-shielding strip, the light passing through the light cone experiences almost no unnecessary light scattering. This design significantly reduces light leakage problems caused by loose splicing, improving overall light efficiency and image uniformity.

[0043] Furthermore, referring to Figure 2The first incident surface 221 is a specular reflective layer, and the second incident surface 222 is a diffuse reflective coating. At the incident end 23 of the light cone, the first incident surface 221 employs a specular reflective layer. The main function of the specular reflective layer is to efficiently guide the incident light into the interior of the light cone through high reflectivity. Since the light emitted by the light source typically has a large divergence angle, the specular reflective layer can maximize the guidance of these rays into the interior of the light cone, preventing premature diffusion or exit of the light cone, thereby improving light efficiency. Unlike the first incident surface 221, the second incident surface 222 of the light cone employs a diffuse reflective coating. The purpose of the diffuse reflective coating is to scatter the incident light, allowing it to be evenly distributed on the exit surface of the light cone after reflection. Compared to the specular reflective layer, the diffuse reflective coating reduces the concentration of the light beam at exit by scattering the light, thus avoiding excessive focusing of the light. By designing the first incident surface 221 as a specular reflection layer and the second incident surface 222 as a diffuse reflection coating, the light cone structure of the present invention can significantly improve the uniformity of the image while ensuring high light efficiency, and reduce the phenomenon of excessively high central brightness and dim edges that is common in traditional light cones.

[0044] In one embodiment, reference is made to Figure 2 The light cone folding structure 22 of this invention is manufactured by a stamping and bending integrated forming process. The stamping and bending integrated forming process involves pressing a metal sheet into shape using a stamping die, and precisely folding the metal sheet to the required folding angle. During this process, the metal material, under the action of the die, undergoes controlled pressure and temperature changes to form the light cone folding structure 22 that meets the design requirements. The core advantage of this process is that, through a single stamping operation, it not only ensures the accuracy of the folded surface shape but also reduces errors and production costs while maintaining structural strength. The stamping and bending integrated forming technology allows the folded portion of the light cone structure to maintain high processing precision during manufacturing, avoiding deformation and reduced optical performance caused by insufficient processing precision in the folded portion of traditional light cones.

[0045] This utility model also discloses a projection device, including the projection light cone structure described in the foregoing embodiments. (Refer to...) Figure 3The projection device of this invention utilizes a light cone structure to optimize the light scattering and light efficiency loss problems commonly found in traditional LCD projectors. In this projection device, the light emitted by the LED light source 10 is optimized and reflected by the light cone structure. The light then passes through optical components such as the collimator 30, liquid crystal display chip 40, and field lens 50, ultimately presenting a clear and uniform projected image on the screen. The folding design of the light cone structure and the adjustment of the light reflection angle allow the light to fully utilize the luminous intensity of the light source when passing through each optical component, improving light uniformity and reducing unnecessary light spread. The projection device disclosed in this invention not only improves the brightness uniformity and light efficiency of the projected image but also simplifies the manufacturing process, reduces production costs, and possesses strong market competitiveness.

[0046] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A projection light cone structure, characterized in that, The light cone body includes a central optical axis, an incident end, an exit end, and a folding structure. The light cone body is a hollow trapezoidal truncated cone extending from the incident end to the exit end. The folding structure is disposed on the inner sidewall of the light cone body and includes a first incident surface and a second incident surface. An angle is provided between the first incident surface and the second incident surface, and the first incident surface is disposed close to the incident end. At least a portion of the light rays are reflected sequentially by the first incident surface and the second incident surface and then deflected toward the central optical axis before exiting.

2. The projection light cone structure according to claim 1, characterized in that, The light cone body also includes a light source base surface, which is located on the side of the incident end away from the exit end. A first tilt angle θ1 is provided between the first incident surface and the light source base surface, and a second tilt angle θ2 is provided between the second incident surface and the light source base surface. The first tilt angle θ1 and the second tilt angle θ2 satisfy: θ2<θ1<θ2+10°.

3. The projection cone structure according to claim 2, characterized in that, The light cone body further defines an incident loop at the incident end, and the distance from the incident loop to the central optical axis is denoted as the first distance a. A folded loop is defined at the connection between the first incident surface and the second incident surface, and the distance from the folded loop to the central optical axis is denoted as the second distance b. The first distance a and the second distance b satisfy: a <b<2a。 4. The projection light cone structure according to claim 3, characterized in that, The distance between the folded loop and the base surface of the light source is denoted as the first height H1, and the first height H1 satisfies: 3mm≤H1≤10mm.

5. The projection light cone structure according to claim 1, characterized in that, The first incident surface is a specular reflective layer, and the second incident surface is a diffuse reflective coating.

6. The projection cone structure according to any one of claims 1 to 5, characterized in that, The folded structure is integrally formed by stamping and bending.

7. The projection cone structure according to any one of claims 1 to 5, characterized in that, The light cone body is composed of a first light cone and a second light cone. The first light cone and the second light cone are hollow trapezoidal truncated cones. The first incident surface is located on the first light cone, and the second incident surface is located on the second light cone.

8. The projection cone structure according to any one of claims 1 to 5, characterized in that, The light cone body also includes a light leakage prevention structure, which is located at the connection between the first incident surface and the second incident surface.

9. The projection cone structure according to claim 8, characterized in that, The light-blocking structure is a black light-shielding strip, which is embedded at the connection between the first incident surface and the second incident surface.

10. A projection device, characterized in that, It includes the projection cone structure as described in any one of claims 1 to 9.

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