CN105299560A - Laser car courtesy lamp optical system formed by combining diffraction optical element and laser device - Google Patents

Abstract

The invention discloses a laser car welcome light optical system combining a diffractive optical element and a laser, comprising a laser irradiation light source and a diffractive optical element, the laser irradiation light source is a divergent light source or a collimated parallel light source; the diffractive optical element is for The diffractive optical element designed according to the parameters of the laser irradiation light source is used to realize the light field distribution required by the optical system. The diffractive optical element of the present invention has the characteristics of small size, simple installation, and low cost, which can greatly reduce the volume of the optical system and reduce the cost of optical products; Fine dust and dirt have little impact on the special-shaped light field, and have low requirements on the application environment. It can adapt to complex and diverse application environments, and fully realizes the high light utilization efficiency of the light field, low cost, simple optical structure design, and small size. , High-precision divergence angle adjustment system, which improves the function and applicability of the optical system.

Description

Laser car welcome light optical system combined with diffractive optical element and laser

technical field

The invention belongs to the field of optics, in particular to a laser car welcome light optical system combined with a diffractive optical element and a laser.

Background technique

In modern technology, with the application and development of the automobile market, auto parts products and corresponding optoelectronic equipment and systems, the application of optoelectronic products in the auto parts application market is becoming more and more extensive, and the requirements for the technical indicators of optoelectronic products are also getting higher and higher. Among them The application market of laser welcome lights with special patterns designed according to specific application requirements is developing rapidly, such as welcome lights products with long-distance oblique irradiation, car welcome lights products with special patterns, and welcome lights projected from the bottom of the car at a large angle Lighting products, etc. The development of products in these fields has put forward complex and harsh requirements for the active lighting light field. The traditional lighting optical system has a complex optical system, large size, high cost, and complicated adjustment, requiring multiple lenses. The movement and joint adjustment of the light field are simple, and the complex and changeable light field distribution cannot be realized, which can no longer meet the needs of the application field. Based on the development of diffractive optics and laser technology, the laser light field for special lighting has been provided. Technical basis, the diffractive optical element is a new type of optical element that has only gradually matured recently. Its design principle is essentially different from traditional refractive optics. It is based on the wavefront phase characteristics of the light field for light field modulation design, which belongs to wavelength-level nano-micro optics. The device can realize hundreds of millions of light field control units in a light field area of 1 mm in size, and can adjust the input light field richly and flexibly, and can almost meet any complex output light field requirements. Its size Small, powerful, and highly efficient in light intensity utilization, it is an important application technology in the field of car welcome lights in the future.

The optical design of the traditional car welcome light field is aimed at the characteristics of light sources (such as halogen lamps, LEDs, etc.), and realizes the light emission by using refractive optical components, such as lenses, reflectors, microlens arrays, lenses, and astigmatism sheets. The secondary modulation of the light field realizes the output of the required light field. The traditional design method is to modulate the incident light field by means of refraction, occlusion, and imaging. The design method has complex optical elements, a large number, very low light utilization efficiency, and single function, which cannot realize complex lighting light fields. For example, traditional design methods cannot realize new application fields such as car welcome lights with large tilt angles, asymmetric correction of light intensity distribution, and long-distance welcome lights over 100 meters. At the same time, the traditional lighting light field design method has large optical devices, high cost, and high requirements for the application environment. Fine dust on the surface of the optical device will cause serious defects in the special-shaped light field. The above factors have caused many problems for the use of this product. Unfavorable factors seriously limit the market application of the product.

Contents of the invention

In order to solve the defects and deficiencies in the above-mentioned prior art, the present invention provides a device that can adapt to complex and diverse application environments, fully realize the high light utilization efficiency of the light field, low cost, simple optical structure design, small size, and high-precision divergence The angle adjustment system greatly improves the function and applicability of the optical system. The laser car welcome light optical system is combined with diffractive optical elements and lasers.

The technical solution of the present invention: a laser car welcome light optical system combined with a diffractive optical element and a laser, including a laser irradiation light source and a diffractive optical element, the laser irradiation light source is a divergent light source or a collimated parallel light source; The above-mentioned diffractive optical element is a diffractive optical element designed according to the parameters of the laser irradiation light source, and it is used to realize the light field distribution required by the optical system.

Preferably, the laser irradiation light source is a collimated parallel light source, and the wavefront of the laser light field is a plane wave or an approximate plane wave.

Preferably, the laser irradiation light source is a divergent light source, and the wavefront of the laser light field is a spherical wave.

Preferably, the diffractive optical element has the function of separately adjusting and processing the divergence angles of the incident light field in the X and Y directions, and uniformizes the divergence angles of the incident light field to realize the special-shaped light of the desired car welcome light pattern. The design of the field is optimized. After the light source irradiates the diffractive optical element, a light field with a specific divergence angle required by the overall optical system is formed.

Preferably, the diffractive optical element has the function of adjusting and processing the luminous size of the incident light field in the X and Y directions respectively, and uniformizes the luminous size of the incident light field to realize the special shape of the required car welcome light pattern The design of the light field is optimized. After the light source irradiates the diffractive optical element, a light field with a specific luminous size required by the overall optical system is formed.

Preferably, the diffractive optical element has a design for phase modulation of the wavefront characteristics of the incident light field, and adjusts the wavefront phase of the incident light field to achieve the design of the special-shaped light field of the required car welcome light pattern optimization.

Preferably, the laser irradiation light source and the diffractive optical element realize the design of the special-shaped light field of the desired car welcome light pattern, and after the light source irradiates the diffractive optical element, a specific light intensity distribution and a specific divergence angle required by the overall optical system are formed. light field.

Preferably, the diffractive optical element is a Fresnel diffractive optical element.

Preferably, the diffractive optical element is a Fraunhofer diffractive optical element.

The diffractive optical element of the present invention realizes the light intensity distribution design of the outgoing light field by modulating the wavefront of the incident light field. The optical elements can replace the functions of various optical devices in the traditional method. The optical elements are few, the size is small, and the light utilization efficiency is greatly improved, which can reach more than 90%. lighting field needs.

The car welcome light system with laser combined with diffractive optical elements, through the combination design of laser light field and diffractive optical elements, can realize arbitrarily complex welcome light patterns with special significance, and based on the small divergence angle of the laser, the beam propagation direction can be Control and long-distance transmission performance, can realize the effect of car welcome light with ultra-long-distance warning function.

The most important advantage of the laser car welcome light optical system is the strong scattering and high visibility of the laser in dense fog weather conditions. In the dense fog weather environment, the visibility of traditional welcome lights is very poor. The thicker the fog, the shorter the visible distance of the traditional welcome light; and based on the directional propagation characteristics of the beam realized by the laser combined with the diffractive optical element, the spatial local light intensity of the beam is very strong, and after being scattered by tiny particles in the fog, a visible The high-intensity visual effect of scattered light with a warning effect effectively realizes the warning visual effect of the welcome light, and its visual distance in the dense fog weather environment is more than 10 times that of the traditional welcome light.

The diffractive optical element of the present invention has the characteristics of small size, simple installation, and low cost, which can greatly reduce the volume of the optical system and reduce the cost of optical products; at the same time, the diffractive optical element has a large tolerance of optical indicators, compared with traditional optical The device, the fine dust and dirt in the light-passing area have little effect on the special-shaped light field, and have low requirements for the application environment, and can adapt to complex and diverse application environments, fully realizing the high light utilization efficiency of the light field, low cost, and The optical structure design is simple, the size is small, and the high-precision divergence angle adjustment system greatly improves the function and applicability of the optical system.

Description of drawings

Fig. 1 is a schematic diagram of the optical structure of the present invention;

Fig. 2 is the optical structure schematic diagram of X direction of laser device and diffractive optical element in the present invention;

Fig. 3 is a schematic diagram of the optical structure of the laser and the diffractive optical element in the Y direction of the present invention.

In Fig. 1, 1. Laser, 2. Diffractive optical element, 3. Laser welcome lamp illuminating the light field.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments, but it is not intended to limit the protection scope of the present invention.

The diffractive optical element in the present invention is based on the needs of the car welcome light system, and according to the optical parameters of the irradiated laser light source, the design of the diffractive optical element is targeted to realize the output of the laser light field with a specific pattern. The diffractive optical element The welcome light field design realized with the laser has high light intensity utilization efficiency, and the shape and light intensity distribution of the light field distribution can be flexibly controlled, and complex welcome lights can be realized according to the needs of different types of car application systems The patterned light field is an optical system that cannot be realized by traditional lighting equipment. The function of the diffractive optical element is: the incident beam is a parallel or divergent laser beam, and the incident beam irradiates the diffractive optical element to realize an outgoing light field. The diffractive optical element is designed and adjusted according to the optical characteristics of the incident light field. The wavefront of the incident light field realizes the Fourier transform from the incident light field to the required exit light field. The position of the laser light source and the diffractive optical element is fixed, and the design of the required complex light intensity distribution light field can be realized only by adjusting one diffractive optical element. The optical function is powerful, and at the same time, the size of the lighting system can be greatly reduced and the Cost, expanding the application field and application mode of the laser lighting system.

Example 1

The laser is selected as a divergent laser (such as a semiconductor laser), and the emitted laser has a certain difference in the divergence angle θx in the X direction and the divergence angle θy in the Y direction, and the luminous size Lx and Ly of the laser are also quite different. The difference is very large, θx is about 40 degrees, θy is about 10 degrees, Lx is 1um, and Ly is 100um.

The laser is selected as a divergent laser (such as a semiconductor laser). The laser spot emitted by the laser has a certain difference in the X-direction size dx and the Y-direction size dy due to the influence of θx and θy. For example, the dx and dy of a semiconductor laser There is a big difference, dx=Lx+tan(θx/2)×2×D, dy=Ly+tan(θy/2)×2×D, where D is the distance between the laser spot test position and the laser light-emitting position .

In order to achieve a good lighting effect of car welcome lights, it is necessary to design diffractive optical elements according to the characteristics of the above-mentioned semiconductor lasers.

Function 1 of the diffractive optical element in this embodiment: Due to the influence of θx and θy, as well as Lx and Ly, the true spherical wave sink focusing point in the X and Y directions is not located on the light-emitting surface of the laser, but along the reverse direction of the spherical wave The intersection point of propagation, as shown in the figure, the distances from the focal point in X direction and Y direction to the diffractive optical element are fx and fy respectively. The X direction inside the diffractive optical element can compress the θx angle (similar to a lens system with a focal length of fx), and the y direction inside the diffractive optical element can compress the θy angle (similar to a lens system with a focal length of fy), The beam of the divergent laser is modulated by the diffractive optical element to form a homogenized beam divergence angle in the X and Y directions. The ratio of θox to θoy is about 1:1, which is used to meet the needs of the subsequent welcome lighting scene processing.

Function 2 of the diffractive optical element in this embodiment: the design incorporates the homogenization design for dx and dy at the same time. Assuming that dx is smaller than dy, the X direction inside the diffractive optical element is capable of performing size processing on dx (similar to a size of dx lens), the y direction inside the diffractive optical element is equipped with size processing for dy (similar to a lens with a size of dy), the laser beam is modulated by the diffractive optical element to form a uniform beam size in the X and Y directions, For example, the use of semiconductor lasers, before the treatment of diffractive optical elements, the ratio of semiconductor laser light emission size in X and Y directions: dx:dy=100:1, after a good design of diffractive optical element parameters, dx:dy=4:1, Significantly improved the ratio of the spot size to meet the needs of the subsequent welcome lighting field.

Function 3 of the diffractive optical element in this embodiment: on the basis of function 1 and function 2, the diffractive optical element performs phase modulation on the beam again, based on the optimized processing results of the laser light of function 1 and function 2 and the required reception According to the needs of the light field, the wavefront of the divergent light is in the form of a spherical wave. The diffractive optical element of the invention performs an iterative analysis of the optical Fourier propagation for the phase distribution of the wavefront of the spherical wave. By modulating the phase of the light field, the output The diffraction and interference effects of the incident light field can achieve the required welcome light effect.

Example 2

The laser is selected as a collimated parallel light laser. The emitted laser has a very small divergence angle θx in the X direction and a divergence angle θy in the Y direction. The laser beam presents a parallel light propagation mode, and its wavefront is a plane wave.

The laser is selected as a collimated parallel light laser. The laser emitted by the laser has a certain difference in the X-direction dimension dx and the Y-direction dimension dy. For example, the dx and dy of the semiconductor laser compressed by the divergence angle of the aspheric lens are different. dx: dy=1:5.

In order to achieve a good lighting effect of car welcome lights, it is necessary to design diffractive optical elements according to the characteristics of the above-mentioned semiconductor lasers.

Function 1 of the diffractive optical element in this embodiment: the design incorporates the design for plane waves, θx and θy are both small angles close to 0, and the diffractive optical element performs phase processing of the same plane wave in the X and Y directions according to this feature .

Function 2 of the diffractive optical element in this embodiment: the design incorporates the homogenization design for dx and dy at the same time, the X direction inside the diffractive optical element is capable of dimensioning dx (similar to a lens with a size of dx), The y direction inside the diffractive optical element is capable of dimensionally processing dy (similar to a lens with a size of dy), and the laser beam is modulated by the diffractive optical element to form a uniform beam size in the X and Y directions, such as through an aspheric lens For the 650nm semiconductor laser with divergence angle compression, the ratio of the X and Y directions of the semiconductor laser light emission size before the treatment of the diffractive optical element: dx:dy=1:5, after the treatment of the diffractive optical element, the spot at a distance of 10mm can achieve dx : dy=1:1, the ratio of the spot size is significantly improved to meet the needs of the subsequent welcome lighting scene.

Function 3 of the diffractive optical element in this embodiment: on the basis of function 1 and function 2, the diffractive optical element performs phase modulation on the beam again, based on the optimized processing results of the laser light of function 1 and function 2 and the required reception The needs of the light field, the wave front wave mode of collimated parallel light, the diffractive optical element of the present invention performs iterative analysis of the optical Fourier propagation for the wave front phase distribution of the plane wave, by modulating the phase of the light field, the outgoing light Field diffraction and interference effects to achieve the required welcome light effect.

Claims (9)

1. with the laser automobile meeting lamp optical system that diffraction optical element and laser instrument combine, it is characterized in that: it comprises a laser radiation source and a diffraction optical element, described laser radiation source is divergent light source or collimation source of parallel light; Described diffraction optical element is carry out for the parameter of laser radiation source the diffraction optical element that designs, and it is for realizing the optical field distribution needed for optical system.

2. the laser automobile meeting lamp optical system of diffraction optical element according to claim 1 and laser instrument combination, is characterized in that: described laser radiation source is collimation source of parallel light, and its laser light field wavefront is plane wave or almost plane ripple.

3. the laser automobile meeting lamp optical system of diffraction optical element according to claim 1 and laser instrument combination, it is characterized in that: described laser radiation source is divergent light source, its laser light field wavefront is spherical wave.

4. the laser automobile meeting lamp optical system of diffraction optical element according to claim 1 and laser instrument combination, it is characterized in that: described diffraction optical element possesses the function X of incident field and the Y-direction angle of divergence being adjusted to respectively to process, the angle of divergence of incident field is carried out Homogenization Treatments, realize the design optimization of the special-shaped light field of required automobile meeting lamp pattern, after light source irradiation diffraction optical element, form the light field possessing the specific angle of divergence that overall optical system needs.

5. the laser automobile meeting lamp optical system of diffraction optical element according to claim 4 and laser instrument combination, it is characterized in that: described diffraction optical element possesses the function X of incident field and the luminous size of Y-direction being adjusted to respectively to process, the luminous size of incident field is carried out Homogenization Treatments, realize the design optimization of the special-shaped light field of required automobile meeting lamp pattern, after light source irradiation diffraction optical element, form the light field possessing the specific luminous size that overall optical system needs.

6. the laser automobile meeting lamp optical system of diffraction optical element according to claim 1 and laser instrument combination, it is characterized in that: the described diffraction optical element wavefront properties possessed for incident field carries out the design of phase-modulation, the Wave-front phase of incident field is carried out being adjusted to process, realizes the design optimization of the special-shaped light field of required automobile meeting lamp pattern.

7. the laser automobile meeting lamp optical system of diffraction optical element according to claim 1 and laser instrument combination, it is characterized in that: described laser radiation source and diffraction optical element realize the design of the special-shaped light field of required automobile meeting lamp pattern, after light source irradiation diffraction optical element, form the light field of the certain light intensity distribution possessing overall optical system and need, the specific angle of divergence.

8. the laser automobile meeting lamp optical system of diffraction optical element according to claim 1 and laser instrument combination, is characterized in that: described diffraction optical element is fresnel diffraction optical element.

9. the laser automobile meeting lamp optical system of diffraction optical element according to claim 1 and laser instrument combination, is characterized in that: described diffraction optical element is Fraunhofer diffraction optical element.