CN101063518A - Reflective Light Projector - Google Patents

Abstract

The present invention is a reflective light projection device, which includes a light guide cover with reflective properties and at least one directional light source. The light guide cover has a reflective surface with a Fresnel-like structure. The Fresnel-like structure adopts the Fresnel lens principle to convert a geometric reflective surface into an equivalent reflective surface. It can be a plane, a curved surface or a combination thereof. The reflective surface with the Fresnel-like structure is arranged at the bottom of the light guide cover, and the light source is arranged on the side wall of the light guide cover. The light emission direction of the light source is adjusted to have a certain matching angle with the Fresnel-like structure, so that the reflected light can be guided to emit from the light guide cover at a certain angle; thereby achieving the purpose of generating high-efficiency and high-collimation parallel light.

Description

Reflective Light Projector

technical field

The present invention relates to a light projection device, in particular to a Fresnel lens principle, which converts a geometric reflective surface into an equivalent reflective surface, and cooperates with a light source that controls the luminous angle to produce high efficiency and high collimation. A light projection device for parallel rays.

Background technique

The light sources of traditional lamps can be roughly divided into two types: point light sources and line light sources. Tungsten filament lamps and energy-saving bulbs are point light sources, while fluorescent tubes are line light sources. When the above two light sources emit light, they emit light in a radial manner. The disadvantage of emitting outward is that it is large in size. Due to the main advantage of small size, light-emitting diodes (LEDs) have been continuously developed and applied to lighting tools in recent years. Moreover, due to the continuous improvement of luminous efficiency, light-emitting diode lamps have become the future The trend of main lighting fixtures; LEDs are planar light sources, and their light-emitting angles are limited. Therefore, general LED lamps use direct or reflective lighting. Moreover, the brightness of a single LED cannot meet the needs of lamps, and multiple LEDs must be used. diodes to provide sufficient brightness.

Please refer to Fig. 1, U.S. Patent No. 6,502,956 "Light emitting diode lamp within individual LED lenses", the patent proposes a direct type lamp, which is provided with a plurality of light emitting diodes 14 on the circuit board 10, the structure Although the light extraction efficiency can be improved, it is accompanied by extremely serious glare, causing discomfort to the viewer. Furthermore, if a single or part of the LEDs 14 is damaged, it will be immediately observed.

Please refer to Figure 2, U.S. Patent No. 6871993 "Integrating LED illumination system formachine vision systems", which proposes a lighting system used in a machine vision system as a barcode scanning system, such as price barcodes used in convenience stores The operating principle of the machine is to focus the light emitted by the light-emitting diodes on the target, and then collect the reflected image data by the machine vision system. As shown in Figure 2, the system 10 mainly includes a reflector 12 and an array of light-emitting diodes 14. The reflector 12 has a focusing reflective surface 13 that can be elliptical, parabolic and hyperbolic, and the LED array 14 includes a base 26 and a plurality of light emitting diodes arranged on the base 26 Diode 16, the light-emitting diode 16 is located inside the focal area of the reflector 12 and illuminates towards the focusing reflective surface 13; the main function of the patent is to make the plurality of light-emitting diodes 16 in the array form a Focused light, whose application is limited to scanning systems, is not suitable for lighting fixtures.

Please refer to Fig. 3, U.S. Patent No. 5,136,483 "Illuminating device", which proposes a vehicle lamp, which includes a reflector 16, a plurality of light-emitting diodes 14 placed on the inner annular side wall of the reflector 16, And heat dissipation fin 19, the light that described light-emitting diode 14 sends can produce parallel light through the reflection of the curved surface bottom of reflector 16; A small part can be reflected by the reflector 16 to produce parallel light. As for the light in other light angle ranges, part of it is scattered out of the reflector 16 at undesired light angles, and some of the light is reflected multiple times inside the reflector 16. Therefore, its light extraction efficiency is not good, and it cannot produce highly collimated parallel light rays. Although the above-mentioned problems can be improved by changing the design of the reflector 16, the design is extremely difficult and there is room for improvement. Not high.

Please refer to FIG. 4 , U.S. Patent No. 5,838,247 "Solid state light system", the lamp 40 disclosed in the patent includes a plurality of light-emitting diodes 12 arranged obliquely, and a reflection mechanism 44 with an inclination angle A. The reflector 44 can be conical or pyramid-shaped, and the light-emitting diode 12 and the reflector 44 can form reflected light parallel to the axial direction 36 by virtue of the cooperation of the inclination angles of the light-emitting diode 12 and the reflector 44, so as to improve the light extraction efficiency, but its disadvantage is that The reflective mechanism 44 described above is a plane, and cannot be accurately matched with the light emitting angle of the light emitting diode 12, so it is still impossible to make all the reflected light emit completely parallel to the axial direction 36. Furthermore, in order to match the inclination of the reflective mechanism 44, it must Installing a large number of light emitting diodes 12 is not only costly and energy wasting, but also leads to an extremely large volume of the lamp, and the appearance of the lamp is also fixed and invariable.

Contents of the invention

In view of the deficiencies in the prior art, the main purpose of the present invention is to propose a reflective light projection device, which converts the geometric reflective surface into an equivalent reflective surface, and cooperates with a light source that controls the luminous angle, which can produce high efficiency and high precision. straight parallel rays.

A secondary purpose of the present invention is to provide a reflective light projection device, which can improve light extraction efficiency.

Another object of the present invention is to provide a reflective light projection device, the shape of the reflective light guide cover is not limited and can be changed.

Another object of the present invention is to provide a reflective light projection device that can avoid glare.

In order to achieve the above purpose, the present invention proposes a reflective light projection device, which includes:

A light guide cover, which has a reflective surface of a type of Fresnel (Fresnel) structure;

At least one light source, whose light output direction has a certain matching angle with the aforementioned Fresnel-like structure of the reflective surface, can guide the reflected light to a certain angle and emit the light guide cover. This matching angle is based on the principle of light reflection, and also That is, it is designed on the principle that the light projection angle is equal to the light reflection angle, which refers to the angle at which the light from the light source can be projected onto the Fresnel structure. For example, if the Fresnel structure equivalent to a paraboloid is implemented, the light source Put it on the focal length of the Fresnel paraboloid equivalent to the paraboloid, adjust the projection matching angle of the light source, so that the light energy can be projected onto the Fresnel (Fresnel) structure, and achieve the purpose of parallel output of reflected light.

Preferably, the plurality of light sources have different matching angles with the Fresnel-like structure of the reflective surface, so that at least one angle of reflected light can be emitted out of the light guide cover.

Preferably, the light guide cover is made of light-reflecting material.

Preferably, the inner wall of the light guide cover is provided with a reflective layer.

Preferably, the reflective layer is formed by electroplating of metal materials such as aluminum or electroless nickel.

Preferably, the Fresnel-like structure is a plane.

Preferably, the Fresnel-like structure is a curved surface.

Preferably, the Fresnel-like structure is a combination of plane and curved surface.

Preferably, the Fresnel-like structure is arranged around a center.

Preferably, the Fresnel-like structure is arranged symmetrically.

Preferably, the Fresnel-like structures are arranged in a parallel extending manner.

Preferably, the vertical section of the reflective surface is a left-right symmetrical slope, and a Fresnel-like structure is arranged on the slope.

Preferably, the vertical section of the reflective surface is a left-right symmetrical curved surface, and a Fresnel-like structure is arranged on the curved surface.

Preferably, the vertical section of the reflective surface is a combination of a left-right symmetrical slope and a curved surface, and a Fresnel-like structure is provided on the slope or curved surface.

Preferably, the light source is a directional light source.

Preferably, the light source is a light emitting diode.

Preferably, the light guide cover includes:

A bottom is for setting the reflective surface with Fresnel-like structure;

At least one side wall is arranged on the side of the bottom, and the side wall is used for setting the light source.

Preferably, the side wall is arranged around the bottom so that the light guide cover has a polygonal periphery.

Preferably, the side wall is arranged as a closed ring around the bottom, so that the light guide cover has a cylindrical shape.

The present invention has the following advantages by controlling the light output angle of the light source and matching the light output mode of the Fresnel-like structure:

All the light emitted by the light source can be completely reflected by the Fresnel-like structure of the light guide cover, which can produce highly collimated parallel light.

All the light emitted by the light source can be completely reflected by the Fresnel-like structure of the light guide cover, which has good light extraction efficiency.

The shape of the light guide cover is flexible.

Can avoid glare.

The size of the lamp can be reduced.

Description of drawings

Figures 1 to 4 are structural schematic diagrams of existing LED lighting devices or lamp patents;

Fig. 5 is the structural representation of the first preferred embodiment of the present invention;

Figure 5A is a schematic diagram of the focusing of reflected light from a parabolic mirror;

Fig. 6 is the structural representation of the second preferred embodiment of the present invention;

Fig. 7 is a schematic structural view of a third preferred embodiment of the present invention;

Figure 8 and Figure 9 are schematic diagrams of two different three-dimensional implementation structures of the present invention;

Fig. 10 is a schematic structural view of a fourth preferred embodiment of the present invention;

Fig. 11 is a schematic structural view of a fifth preferred embodiment of the present invention;

Fig. 12A, Fig. 12B and Fig. 12C are diagrams showing the distribution of illuminance at different distances from the simulated lamps.

Explanation of reference numerals: 10, 110, 110a, 110b, 210, 310, 410-light guide cover; 11, 111, 111a, 111b, 211, 411-bottom; 12, 112, 112a, 112b, 212, 312, 412a ～412c-light outlet; 13, 113, 113a, 113b, 213, 413-side wall; 20, 20a～20d-light source; 30, 30a～30d-like Fresnel structure; 31, 31a～31c-reflecting surface; 214, 215, 40-curved surface extension direction; Lc-axial direction; L1, L1a～L1c-emitted light; L2, L2a～L2d-reflected light; θ, θa～θc-angle.

Detailed ways

The technical means and effects used by the present invention to achieve the purpose will be described below with reference to the attached drawings.

Please refer to FIG. 5, a reflective light projection device provided by the present invention includes a light guide cover 10 and at least one light source 20. The light guide cover 10 is made of a material with reflective properties. The inner sidewall of the light guide cover 10 can be provided with a reflective layer (not shown) to improve the light reflectivity, the material of the reflective layer can be the existing reflective diffusion film used in flat panel displays, or can be made of Metal materials such as aluminum or electroless nickel are formed by electroplating. The light source 20 is preferably a directional light source with a certain light output angle, such as a light emitting diode. The light guide cover 10 has a bottom 11 and at least one light output port. 12. A feature of the present invention is that the bottom 11 of the light guide cover 10 is provided with a Fresnel-like structure 30, and the Fresnel-like structure 30 is composed of a plurality of reflective surfaces 31 and presents sawtooth shape, the reflective surface 31 can be a plane or a curved surface with a curvature, and each reflective surface 31 can be a plane with a different angle or a curved surface with a different curvature, and the light source 20 is set at an angle θ On the upper edge of the side wall 13 of the light guide cover 10 on the periphery of the light outlet 12, the light source 20 has a certain light output angle, and each reflective surface 31 of the Fresnel-like structure 30 matches the light output angle of the light source 20. In this way, the emitted light L1 projected by the light source 20 onto the Fresnel-like structure 30 can completely form the reflected light L2 parallel to the axial direction Lc and exit the light guide cover 10, so as to achieve the best light extraction efficiency.

The matching angle (that is, the so-called incident angle) between the aforementioned light source 20 and each reflective surface 31 of the Fresnel-like structure 30 is based on the principle of light reflection, that is, the principle that the light projection angle is equal to the light reflection angle. Moreover, as shown in Figure 5A, when a paraxial ray Ra incident on the concave parabolic mirror Pa parallel to the main axis, it must pass through the focal point F after reflection. In other words, the light parallel to the main axis can be converged At the focal point, according to the above principles, the curvature of the parabolic mirror can be extracted, and converted into an equivalent flat prism using Matlab (MatrixLaboratory) mathematical calculation software, which is the Fresnel structure of the present invention. Its type can refer to the Fresnel-like structure 30 shown in FIG. 5; On the focal length of the parabolic reflective surface 31 of the structure 30, the projection matching angle of the light source 20 is adjusted so that the light source 20 is projected onto the reflective surface 31, so that the parallel output of reflected light can be achieved.

As for the installation position of the light source 20, it depends on the position of the light outlet 12 and the structure of the Fresnel-like structure 30, and is not limited to the upper edge of the side wall 13 of the light guide cover 10 shown in the figure. The structure of the light guide cover 10 will also be different according to the change of the arrangement positions of the light source 20 and the Fresnel-like structure 30, and the structure of the light guide cover 10 shown here is only for illustration.

Here is a brief description of the structure of the Fresnel (Fresnel) lens, which is an optical component with a plano-convex or plano-concave lens that converges or diverges light. The surface forms a zigzag concentric ring. The curved surface of a spherical or aspheric lens is divided into many concentric rings, and then each concentric ring is moved to the same plane to form. If it is translated and extended, parallel sawtooth rows can be formed on the plane. Its main advantage is that it has good Focusing ability, so it is widely used in optical instruments; the present invention develops a "Fresnel-like (Fresnel) structure" based on the focusing principle of the above-mentioned Fresnel lens, and applies it to light-emitting diode lamps in conjunction with the light-emitting diode light angle. The light extraction efficiency of the light-emitting diode lamp can be improved.

Based on the reflection principle of the embodiment shown in FIG. 5, the structure shown in FIG. 6 can be derived. The light guide cover 110 has a bottom 111 and a light outlet 112, with the axis Lc as the central axis, and a Fresnel-like The cooperation between the light source 20 and the Fresnel-like structure 30 on the right side of the axial direction Lc is the same as the embodiment shown in FIG. the reflected light L2, adjust the light source 20a to cooperate with the reflective surface 31a of the Fresnel-like structure 30a, and set it on the side wall 113 of the light guide cover 110 on the periphery of the light outlet 112 at an angle θa Edge, the direction of the reflected light L2a generated after the emitted light L1a of the light source 20a is projected on the reflective surface 31a is parallel to the axial direction Lc. The Fresnel-like structures 30, 30a cooperate, and the reflected light L2, L2a emits the mask 110 towards the same light outlet 112, so that the best light extraction efficiency is achieved; similarly, when the Fresnel-like structure described 30 and 30a have the same structure, and when the inclination angles θ and θa of the light sources 20 and 20a are the same, naturally reflected light L2 and L2a parallel to the axis Lc can also be generated.

Based on the reflection principle of the embodiment shown in FIG. 6, the structure shown in FIG. 7 can be derived. The light guide cover 210 has a bottom 211 and a light outlet 212, and a Fresnel-like Structures 30b, 30c, the characteristic of this embodiment is that the described Fresnel-like structures 30b, 30c are arranged on a curved surface 214, 215, and are composed of a plurality of reflective surfaces 31b, 31c and present a zigzag shape. The direction of the reflective surface 31b, 31c, the light sources 20b, 20c are inclined at different angles θb, θc and arranged on the upper edge of the side wall 213 of the light guide cover 210 on the periphery of the light outlet 212. Similarly, the light sources 20b, 20c After the emitted light L1b, L1c of 20c is projected on the reflective surfaces 31b, 31c of the Fresnel-like structures 30b, 30c, it can generate reflected light L2b, L2c parallel to the axial direction Lc, and emit the above-mentioned mask toward the same light outlet 212 210; Of course, if the structures of the Fresnel-like structures 30b and 30c are the same, the curvatures of the curved surfaces 214 and 215 are the same, and the inclination angles θb and θc of the light sources 20b and 20c are the same, naturally The reflected light L2b, L2c parallel to the axis Lc can be generated, the principle of which is the same as that of the above-mentioned different embodiments, and will not be repeated here.

Please continue to refer to FIG. 8 and FIG. 9, which respectively show two different three-dimensional forms derived from the embodiment of the light guide cover 110 shown in FIG. 6. As shown in FIG. 8, the light guide cover 110a is a three-dimensional Long rectangle, with a bottom 111a and a light outlet 112a, symmetrical side walls 113a are arranged outside the light outlet 112a, the light sources 20, 20a are arranged on the upper edge of the two side walls 113a, the The light sources 20, 20a respectively have an inclination angle θ, θa to cooperate with the Fresnel-like structure 30d arranged on the bottom 111a (indicated by the dotted line in the figure), and the structure of the Fresnel-like structure 30d can be Arrange the Fresnel-like structures 30, 30a-30c as shown in Fig. 5 to Fig. 7 according to the requirements, and arrange them in parallel strips on the bottom in parallel to the extension direction A of the light sources 20, 20a. 111a.

As shown in Figure 9, the light guide cover 110b is in the shape of a three-dimensional cylinder (the axial section is shown in the figure), which has a bottom 111b and a side wall 113b surrounding the central axis Lc. A light outlet 112b is formed in the center of 113b. Similarly, the light source 20 cooperates with the Fresnel-like structure (not shown in the figure) arranged on the bottom 111b, and is arranged on the side wall with an inclination angle θ For the upper edge of 113b, as for the structure of the Fresnel-like structure, the Fresnel-like structures 30, 30a-30c shown in Figures 5 to 7 can be arranged according to the needs, and the structure is formed around the central axis Lc. An annular manner is provided on said bottom 111b.

According to the above-mentioned different embodiments, the feature of the present invention is that no matter what kind of Fresnel-like structure is, as long as the light source has an emission angle matched with the Fresnel-like structure, the desired direction of reflected light can be generated, and the Light sources at different positions can be adjusted to have the same light angle, or light sources with different light angles can be combined with Fresnel-like structures with different reflective surfaces to generate parallel light rays in a single direction with high efficiency and high collimation.

Accordingly, please refer to the different combination embodiments shown in FIG. 10 and FIG. 11 . As shown in FIG. 10 , it combines the structures in FIG. 5 and FIG. , 30c, in conjunction with the corresponding light sources 20, 20c, can form the reflected light L2, L2c emitted towards the same light outlet 312; and the light guide cover 410 as shown in Figure 11 has a multi-layer side wall 413, forming different The light outlets 412a-412c, the side wall 413 can provide light sources 20a-20d with different angles, cooperate with Fresnel-like structures 30a-30c or geometric curved surfaces 40 of different structures, and can obtain parallel reflected light L2a- L2d is to form a single light beam to exit the light guide cover 410. Similarly, if the light emitting directions of the light sources 20a-20d are changed and the Fresnel-like structures 30a-30c of different structures are used, complex reflections at different angles can be produced. The light exits the light guide cover.

In addition, it must be emphasized that the structure of the above-mentioned different preferred embodiments of the present invention has been confirmed by the inventor to be feasible by means of professional software simulation; it is known that there are many optical lighting simulation analysis programs and software on the market, such as Photopia, OptiBPM, OSLO, etc. Among them, Photopia is a photometric analysis program widely used in the design of lighting fixtures. It can provide operators with virtual lighting fixtures based on physical prototypes, and test various design possibilities through computer modeling without having to recreate the model. , which can make a comprehensive performance evaluation for non-image optical design and evaluate the performance of lamps; as shown in Figure 12A to Figure 12C, they respectively display the illuminance distribution of the photosensitive screen (detector) at three different distances from the simulated lamps: 600mm, 700mm, and 800mm As shown in the figure, a parabolic mirror with a diameter of 290mm and a focal length of 100mm is set, and the curvature of the parabolic mirror is equivalent to a flat tooth reflector to obtain the advantages of lightness, smallness and thinness. The illuminance distribution diagrams of 600mm to 800mm are all about 250mm in diameter, so it can be estimated from the simulation results that the light is a collimated outgoing light.

The above descriptions are only preferred embodiments of the present invention, and are only illustrative rather than restrictive to the present invention. Those skilled in the art understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present invention, but all will fall within the protection scope of the present invention.

Claims (20)

1, a kind of reflection type light projector device, it is characterized in that: it comprises:

One light-guiding shade, it has a bottom and at least one light-emitting window, and described bottom is for the reflecting surface that at least one class Fresnel structure is set, and forms the sidewall of described light-guiding shade in the periphery of described light-emitting window;

At least one sensing light source is arranged on the sidewall of aforementioned light-guiding shade.The class Fresnel structure of its light direction and aforementioned described reflecting surface has certain fit angle, and the guides reflected light certain angle is penetrated described light-guiding shade.

2, reflection type light projector device as claimed in claim 1, it is characterized in that: described directive property light source is a plurality of, described plural light source light direction has different fit angle with described class Fresnel structure respectively, and the reverberation that produces at least a angle penetrates described light-guiding shade.

3, reflection type light projector device as claimed in claim 1, it is characterized in that: described directive property light source is the light source of plural different rising angles, the class Fresnel structure of plural different structure is set on the described bottom, and the reverberation that produces plural different angles penetrates described light-guiding shade.

4, reflection type light projector device as claimed in claim 1 is characterized in that: described light-guiding shade is to be made of the material with reflective characteristic.

5, reflection type light projector device as claimed in claim 1 is characterized in that: sidewall is provided with reflector layer within the described light-guiding shade.

6, reflection type light projector device as claimed in claim 5 is characterized in that: described reflector layer is the diffusion barrier sheet for reflection-type.

7, reflection type light projector device as claimed in claim 5 is characterized in that: described reflector layer is by aluminium or does not have the electrolytic nickel metal material and electroplate and to form.

8, reflection type light projector device as claimed in claim 1 is characterized in that: described class Fresnel structure is to be the plane.

9, reflection type light projector device as claimed in claim 1 is characterized in that: described class Fresnel structure is to be curved surface.

10, reflection type light projector device as claimed in claim 1 is characterized in that: described class Fresnel structure is the combination for plane and curved surface.

11, reflection type light projector device as claimed in claim 1 is characterized in that: described class Fresnel structure is to be provided with in the mode around a center.

12, reflection type light projector device as claimed in claim 1 is characterized in that: described class Fresnel structure is with the mode of left and right symmetry setting.

13, reflection type light projector device as claimed in claim 1 is characterized in that: described class Fresnel structure is to be provided with in the mode that extends in parallel.

14, reflection type light projector device as claimed in claim 1 is characterized in that: the vertical section of described reflecting surface is symmetrical inclined-plane, is provided with the class Fresnel structure on described inclined-plane.

15, reflection type light projector device as claimed in claim 1 is characterized in that: the vertical section of described reflecting surface is symmetrical curved surface, is provided with the class Fresnel structure on described curved surface.

16, reflection type light projector device as claimed in claim 1 is characterized in that: the vertical section of described reflecting surface is the combination of symmetrical inclined-plane and curved surface, is provided with the class Fresnel structure on described inclined-plane or curved surface.

17, reflection type light projector device as claimed in claim 1 is characterized in that: described directive property light source is a light emitting diode.

18, reflection type light projector device as claimed in claim 1 is characterized in that: described sidewall is around described bottom periphery setting, makes described light-guiding shade have a polygon periphery.

19, reflection type light projector device as claimed in claim 1 is characterized in that: described sidewall is the annular that is set to a sealing around described bottom periphery, makes described light-guiding shade have a cylindrical outer shape.

20, reflection type light projector device as claimed in claim 1 is characterized in that: described light-guiding shade has plural sidewall to form the light-emitting window of plural number.

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