An optical system for generating a rectangular light spot

Abstract

The utility model discloses an optical system for generating rectangular light spot, including the light source module, first lens, second lens and third lens that install in proper order, the light ray of light source module shoots through first lens, and first lens emits preformed light spot, and the preformed light spot passes through second lens, and second lens emits uniform light spot, and the uniform light spot passes through third lens, and third lens emits rectangular light spot, and first lens is the free -form lens, and the light -emitting surface of first lens is rectangular aspheric surface, the utility model reaches the beneficial effect is: improves the light efficiency utilization through the special lens setting.

Description

Technical Field

[0001] This utility model relates to the field of lens device technology, and in particular to an optical system for generating rectangular light spots. Background Technology

[0002] As LEDs are widely used in projection displays, the problems associated with LED light sources are gradually gaining attention. LEDs have a near-Lambertian light distribution curve with an initial divergence angle of 120 degrees. To achieve collimated beam output, the light angle needs to be adjusted through a lens; however, this results in light energy loss at the edges, leading to a relative reduction in system luminous efficiency.

[0003] Therefore, the purpose of this invention is to achieve high effective light utilization in directional lighting applications such as projection lighting through the design of optical lenses. Utility Model Content

[0004] The purpose of this invention is to propose an optical system for generating rectangular light spots, which can improve the light efficiency.

[0005] The purpose of this utility model is to achieve an optical system for generating rectangular light spots through the following technical solution, including a coaxial light source module of equal height, a first lens, a second lens, and a third lens; The light emitted from the light source module passes through the first lens, from which a pre-shaped light spot is emitted; the pre-rectangular light spot passes through the second lens, from which a uniform light spot is emitted; the uniform light spot passes through the third lens, from which a rectangular light spot is emitted. The first lens is a freeform lens, and the light-emitting surface of the first lens is a rectangular aspherical surface.

[0006] The light-emitting surface of the first lens is divided into multiple cross-sections along the X-axis or Y-axis direction. The contour curve of the single-sided cross-section in the X-axis direction satisfies a first curve equation, and the contour curve of the single-sided cross-section in the Y-axis direction satisfies a second curve equation. Wherein, the X-axis is the length direction of the first lens, and the Y-axis is the width direction of the first lens. The equation of the first curve is: ; in, , For the first radius of curvature, the =1.86437; The first conic coefficient, the =0.031572; express The radial distance of a point in the direction perpendicular to the optical axis, i.e., from the optical axis to... Distance between points; The equation of the second curve is: ; in, , For the second radius of curvature, the =1.802; The second conic coefficient, the =-0.0151252; The light-emitting surface is formed by connecting the contour curves of various cross-sections along the X-axis or Y-axis.

[0007] Furthermore, the refractive index of the first lens is as follows: 1.5≤Nd≤1.6; where Nd is the refractive index of the first lens. Preferably, Nd=1.53.

[0008] Furthermore, the diameter of the light-transmitting surface of the second lens is d1, wherein 22mm ≤ d1 ≤ 28mm. Preferably, the diameter of the light-transmitting surface of the lens is 25mm.

[0009] Furthermore, the distance between the light-emitting surface of the first lens and the light-incident surface of the second lens along the optical axis is d2, wherein 5.0mm≤d2≤6.0mm, preferably 5.5mm.

[0010] Furthermore, the third lens includes an incident surface and an exit surface. The incident surface of the third lens (4) is a rectangular surface, the exit surface of the third lens is an aspherical surface, and the longitudinal section of the exit surface of the third lens is a spherical surface.

[0011] Furthermore, the rectangular surface of the third lens has a cutting size of 8mm*6mm.

[0012] This utility model has the following advantages: This invention utilizes a freeform surface lens, i.e., a first lens, integrated within an LED light source. This first lens performs initial angle compression on the original light beam, converging the emitted half-angle within a certain range and forming a pre-rectangular light spot. Subsequently, a second lens, i.e., a freeform surface shaping lens, and a third lens, i.e., a rectangular collimating lens, are set to form a composite optical system. The second lens performs spot homogenization processing on the light beam passing through the first lens to obtain a uniform light spot, and the third lens performs final beam shaping and divergence angle control on the uniform light spot to obtain a rectangular light spot. This optical system reduces energy cutting losses of subsequent optical components through pre-packaging-level beam convergence. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the optical system of this utility model; Figure 2 This is a schematic diagram of the first lens of this utility model in the XY direction; Figure 3 This is a schematic diagram of the emitted light spot of the optical system of this utility model. Detailed Implementation

[0014] The present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.

[0015] It should be noted that the orientation or positional relationship indicated by terms such as "left" and "right" is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this utility model is usually placed in during use, or the orientation or positional relationship that is commonly understood by those skilled in the art. Such terms are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0016] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other. Example

[0017] See Figure 1 This utility model provides a projector lighting system and a projector, including a light source module 1, a first lens 2, a second lens 3 and a third lens 4 arranged coaxially at the same height; the light source module 1 includes an LED light source; The light emitted from the light source module 1 passes through the first lens 2, and the first lens 2 emits a pre-shaped light spot; the pre-rectangular light spot passes through the second lens 3, and the second lens 3 emits a uniform light spot; the uniform light spot passes through the third lens 3, and the third lens 3 emits a rectangular light spot; the first lens 2 is a freeform lens, which refers to an optical element whose one or two surfaces are complex three-dimensional curved surfaces that are not rotationally symmetric. This surface shape can be designed according to specific lighting or imaging requirements to achieve high-precision control of the beam distribution, direction, shape, etc.; the light-emitting surface of the first lens 2 is a rectangular aspherical surface.

[0018] By integrating a first lens 2 into the LED light source, the original light beam is compressed at the initial angle, and the emission half-angle is converged within a certain range to form a pre-rectangular light spot. Then, a second lens 3 is set to obtain a uniform light spot and a third lens 4 to obtain a rectangular light spot, thus forming a composite optical system.

[0019] See Figure 2The first lens 2 includes a body, which is surrounded by an incident surface, a side surface, and an exit surface. The incident surface is the bottom plane of the lens, the side surface is disposed on the base surface and is formed around the base surface, and the exit surface is a curved surface. The length direction of the body is defined as the X-axis, and the light rays along the X-axis are defined as being uniformly distributed. The width direction of the body is defined as the Y-axis, and the light rays along the Y-axis are defined as being less bright from the center to the edge. The vertical direction of the body is defined as the Z-axis, and its origin is the center point of the bottom plane of the lens. The light-emitting surface of the first lens 2 is divided into multiple sections along the X-axis or Y-axis direction. The contour curve of the single-sided section in the X-axis direction satisfies the first curve equation, and the contour curve of the single-sided section in the Y-axis direction satisfies the second curve equation. The equation of the first curve is: ; in, , For the first radius of curvature, the =1.86437; The first conic coefficient, the =0.031572; =0.00000E+00 =1.34283E-02 = -1.25563E-02 =4.66453E-03 =-6.18076E-04.

[0020] The equation of the second curve is: ; in, , For the second radius of curvature, the =1.802; The second conic coefficient, the =-0.0151252; =0.00000E+00 =2.53601E-02 =-2.11388E-02 =7.27005E-03 =-8.79008E-04 The light-emitting surface of the first lens 2 is formed by connecting the contour curves of various cross-sections in the X-axis or Y-axis direction.

[0021] In some specific embodiments, the refractive index of the first lens satisfies the following relationship: 1.5≤Nd≤1.6; where Nd is the refractive index of the first lens; preferably, Nd=1.53.

[0022] In some specific embodiments, the diameter of the light-transmitting surface of the second lens 2 is d1, wherein 22mm ≤ d1 ≤ 28mm. Preferably, the diameter of the light-transmitting surface of the lens is 25mm.

[0023] In some specific embodiments, the distance between the light-emitting surface of the first lens 2 and the light-incident surface of the second lens 3 along the optical axis is d2, wherein 5.0mm≤d2≤6.0mm, and preferably 5.5mm.

[0024] In some specific embodiments, the third lens 4 includes an incident surface and an exit surface. The exit surface of the third lens 4 is aspherical, and the longitudinal section of the exit surface of the third lens 4 is spherical. The incident surface of the third lens 4 is a rectangular surface with a cutting size of 8mm*6mm, and the exit surface of the third lens is a convex curved surface that transitions to the rectangular surface.

[0025] See Figure 3 When an LED light source is selected for the light source module, the LED light source has an approximate Lambertian light distribution curve characteristic, with an initial divergence angle of 120 degrees, corresponding to a circular distribution of the emitted light spot; the first lens 2 adopts a rotationally symmetric aspherical optical design to receive and control the radiated light from the LED light source, which, after refraction, forms a pre-rectangular light spot with a diameter matching the diagonal length of the effective light-transmitting surface of the second lens 3. This stage of optical processing compresses the beam divergence angle to a certain range while maintaining the approximate circular symmetry of the light spot shape; the second lens 2 contains a rotationally symmetric aspherical collimator that has been rectangularly cut, and its incident surface is geometrically optimized into a rectangular profile. Through the synergistic effect of this optical interface and the output surface, the beam collimation output is achieved, ultimately forming a rectangular light spot with a divergence angle ≤12 degrees.

[0026] This invention presents a primary lens structure that, by optimizing the distribution of light rays in the optical path and the lens curvature parameters, significantly improves light energy utilization under small-angle uniform rectangular spot illumination conditions. Compared to traditional structures, this system can improve luminous efficiency by more than 10%, effectively overcoming the optical efficiency bottleneck caused by the limitation of simultaneously satisfying small angle and uniform rectangular spot conditions in conventional designs.

[0027] The above embodiments only illustrate preferred implementation methods, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from this utility model, and these all fall within the protection scope of this utility model.

Claims

1. An optical system for generating rectangular light spots, characterized in that: It includes a coaxial light source module (1) of equal height, a first lens (2), a second lens (3) and a third lens (4); The light emitted from the light source module (1) passes through the first lens (2), the first lens (2) emits a pre-shaped light spot to the second lens (3), and the uniform light emitted from the second lens (3) is emitted to the third lens (4) to form a rectangular light spot; The first lens (2) is a freeform lens, and the light-emitting surface of the first lens (2) is a rectangular aspherical surface.

2. The optical system for generating a rectangular light spot according to claim 1, characterized in that, The light-emitting surface of the first lens (2) is divided into multiple sections along the X-axis and / or Y-axis directions. The contour curve of the single-sided section in the X-axis direction satisfies the first curve equation, and the contour curve of the single-sided section in the Y-axis direction satisfies the second curve equation. The X-axis is the length direction of the first lens (2), and the Y-axis is the width direction of the first lens (2). The light-emitting surface is formed by connecting the contour curves of various cross-sections along the X-axis or Y-axis.

3. The optical system for generating a rectangular light spot according to claim 2, characterized in that, The refractive index of the first lens (2) satisfies the following relationship: 1.5≤Nd≤1.6; where Nd is the refractive index of the first lens.

4. The optical system for generating a rectangular light spot according to claim 1, characterized in that, The diameter of the light-transmitting surface of the second lens (3) is d1, 22mm≤d1≤28mm.

5. An optical system for generating a rectangular light spot according to claim 4, characterized in that, The distance between the light-emitting surface of the first lens (2) and the light-incident surface of the second lens (3) along the optical axis is d2, 5.0mm≤d2≤6.0mm.

6. The optical system for generating a rectangular light spot according to claim 1, characterized in that, The third lens (4) includes an incident surface and an exit surface. The incident surface of the third lens (4) is a rectangular surface, and the exit surface of the third lens (4) is an aspherical surface. The longitudinal section of the exit surface of the third lens (4) is a spherical surface.

7. An optical system for generating a rectangular light spot according to claim 6, characterized in that, The rectangular cut size of the third lens (4) is 8mm*6mm.

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