CN-122015035-A - Low-power consumption direct-injection type coaxial light source

Abstract

The invention discloses a low-power consumption direct-injection type coaxial light source, and relates to the technical field of machine vision illumination. The light source mainly comprises a light source module, a reflecting cover and a light coordinate offset correction device. The reflecting cover is designed into a parabolic structure, the focus of the reflecting cover coincides with the light source, light rays emitted by the LED can be efficiently reflected into collimated light, the light ray utilization rate and the direction consistency are obviously improved, and therefore power consumption and heat generation are reduced. The light coordinate offset correction device consists of two prisms which are vertically arranged and have the same parameters, and through accurate geometric layout, the transverse offset generated by light in two refraction is mutually offset, and finally, the emergent light path has no coordinate deviation. The invention effectively solves the technical problems of low light efficiency, serious heating and inaccurate positioning caused by light deflection of the traditional coaxial light source, and is particularly suitable for high-precision visual positioning and scene detection.

Inventors

• XU WEI
• XIE YINGXI
• CHEN HANXIAN
• LU LONGSHENG
• YANG SHU
• XING DI

Assignees

• 华南理工大学
• 惠州市德赛西威汽车电子股份有限公司

Dates

Publication Date

20260512

Application Date

20260402

Claims (10)

1. 1. A low power direct-lit coaxial light source, comprising: A light source module including at least one light emitting unit; The reflecting cover is arranged on the light emitting side of the light source module, and the inner surface of the reflecting cover is configured to reflect the light rays emitted by the light emitting unit to form collimated emergent light parallel to the optical axis; The light coordinate offset correction device is arranged in the light emitting direction of the reflecting cover and comprises a first prism and a second prism, wherein the first prism and the second prism are vertically arranged, the materials and the thickness are the same, and an incidence plane of the first prism and the propagation direction of the collimated emergent light form an included angle pi/4; The emergent light collimated by the reflecting cover sequentially passes through the first prism and the second prism to be refracted, the final emergent direction is parallel to the direction before entering the first prism, and the transverse coordinate offset caused by refraction is corrected.
2. 2. The direct-injection coaxial light source of claim 1, wherein the inner surface of the reflecting cover is a paraboloid, the focal point of the paraboloid coincides with the light-emitting unit, and the symmetry axis coincides with the optical axis of the light-emitting unit.
3. 3. The direct-injection coaxial light source with low power consumption according to claim 2, wherein the equation of the paraboloid in the rectangular coordinate system is: Wherein, the Is the focal length of a parabola, and 。
4. 4. A low power direct-lit coaxial light source of claim 3, wherein the focal length is Half angle of light emission with light emitting unit The following relationship is satisfied: Wherein, the Is the radius of the opening of the reflector.
5. 5. The low power direct-emission coaxial light source of claim 4, wherein said reflective surface of said reflector is formed by discretizing, comprising the steps of: equally dividing the luminous half-angle interval of the luminous unit into N parts, wherein N is more than or equal to 100; Solving corresponding point coordinates on the outline of the reflecting cover based on a reflection law aiming at the incident light rays corresponding to each equivalent angle; fitting all the contour points obtained by solving into a continuous reflecting curved surface.
6. 6. The direct-injection coaxial light source of claim 1, wherein the first prism and the second prism have refractive indices n greater than that of air, and wherein the first prism and the second prism have thicknesses d that are equal.
7. 7. The direct-injection coaxial light source of claim 6, wherein said first prism and said second prism are integrally formed as an L-shaped prism structure.
8. 8. The direct-injection coaxial light source of claim 6, wherein the light ray coordinate shift correction device generates lateral shifts in the first prism and the second prism of the light ray And The method comprises the following steps: Wherein, the And The incidence angles of the light rays on the first prism and the second prism respectively, And The refraction angles of the light rays in the first prism and the second prism are respectively.
9. 9. The direct-injection coaxial light source of claim 1, wherein the light source module comprises a plurality of light emitting units arranged in an annular array and positioned in a focal region of the reflector.
10. 10. The direct-emission type coaxial light source with low power consumption according to claim 9, wherein the light emitting unit is an LED, and the light emitting half angle θ is in the range of 0 to 45 °.

Description

Low-power consumption direct-injection type coaxial light source Technical Field The invention relates to the technical field of machine vision illumination, in particular to a low-power-consumption direct-injection type coaxial light source. Background In the fields of visual inspection, precision manufacturing and the like, the coaxial light source is used as a core imaging auxiliary component, and the use requirements of high illumination and high stability are required to be met so as to resist the interference of external environment and ensure the detection precision and the imaging quality. However, the existing coaxial light source has a plurality of technical defects in practical application, so that the suitability of the coaxial light source in a high-precision scene is severely restricted, and the specific problems are as follows: The existing coaxial light source does not optimally design the outgoing direction of the light, so that the light is in a 180-degree wide-range divergence state, the light occupation ratio of an effective irradiation target area is extremely low, and the brightness loss is serious. In order to make up for the insufficient brightness to meet the scene illumination demand, the existing product has to adopt a high-power design, which directly causes the obvious heating problem, the heat consumption of the light source under the power operation is large, the heat dissipation efficiency is low, the long-time work can not only accelerate the aging of the internal elements of the light source, but also greatly shorten the service life of the light source, and the stability of peripheral detection equipment can be influenced by high temperature. Meanwhile, due to the global illumination effect caused by high power, non-target features and a background in a field of view can be lightened synchronously, so that target imaging features are difficult to distinguish from surrounding environments, imaging contrast is greatly reduced, and feature identification and data acquisition accuracy in field operation are seriously affected. The working mechanism of the existing coaxial light source has inherent defects from the light propagation principle. The light propagation path is that the light emitted by the light source is reflected to the surface of the product by the reflecting prism, and the reflected light of the product can enter the receiving devices such as a camera and the like (shown in figure 1) after passing through the reflecting prism again. In this process, the light rays need to undergo multiple medium conversions of photophobic medium-dense medium-photophobic medium, and refraction phenomenon is generated due to the difference of the medium density, so that the coordinates of the light rays in the horizontal direction are shifted (as shown in fig. 3). The offset has particularly prominent influence in scenes with extremely high requirements on the precision of the coordinates, such as fitting detection, precise positioning and the like, that software cannot acquire the real coordinates of product features under a world coordinate system, and a control instruction generated based on the offset coordinates is difficult to realize extremely centering, so that the positioning error is increased finally, and the requirement of high-precision operation cannot be met. In summary, the problems of low light divergence utilization rate, serious heat generation caused by the shift of the coordinates of the emergent light and low imaging contrast caused by high power of the existing coaxial light source become key bottlenecks for limiting the further application of the coaxial light source in the field of high-precision visual detection, and a novel coaxial light source design scheme capable of specifically solving the defects is needed. Disclosure of Invention The invention aims to provide a low-power consumption direct-injection type coaxial light source, which aims to effectively solve the technical problems of low light efficiency, serious heating and inaccurate positioning caused by light ray deviation of the traditional coaxial light source, and is particularly suitable for high-precision visual positioning and scene detection. In order to achieve the above object, the present invention provides a low-power direct-injection type coaxial light source, comprising: A light source module including at least one light emitting unit; The reflecting cover is arranged on the light emitting side of the light source module, and the inner surface of the reflecting cover is configured to reflect the light rays emitted by the light emitting unit to form collimated emergent light parallel to the optical axis; The light coordinate offset correction device is arranged in the light emitting direction of the reflecting cover and comprises a first prism and a second prism, wherein the first prism and the second prism are vertically arranged, the materials and the thickness are the same, and a