An ultra-short-focus light guide structure

Abstract

The present invention relates to an ultra-short-focus light-guiding structure, comprising a reflective structure layer, the reflective structure layer is tilted upward or downward, the tilt angle is ≥18° and less than 42°, the reflective structure layer comprises a plurality of reflective structures, the duty ratio formed by the aperture size of the reflective structure and the period of the reflective structure layer is ≥0.5 and <1, and the period of the reflective structure layer is ≥50um and ≤300um. The beneficial effects of the present invention are: it can guide light at a large angle, make the light intensity evenly distributed, better absorb the stray light of the environment and secondary reflections around, and solve the influence of ambient light on the projection picture.

Description

Technical Field

[0001] The invention relates to the field of optical projection, and in particular to an ultra-short-focus light-guiding structure. Background Art

[0002] With the development of the projector industry and to meet the current market demand, ultra-short-throw projectors are gradually entering people's living environment. Ultra-short-throw projectors can achieve ultra-short-throw projection, which greatly saves projection space and can be used in small commercial places, home theaters and other occasions with limited projection space. For ultra-short-throw projectors, there are many factors that affect the imaging effect, including the brightness, contrast, color saturation, lens, etc. of the projector itself. However, in actual use, the main factor that plays a decisive role in the projection effect is the strength of external ambient light and stray light. In short, the impact of ambient light on the projection picture is still obvious. As a picture carrier, the projection screen is not only required to be suitable for the optical path requirements of the ultra-short-throw projector, to prevent the projection light from being wasted during the projection process, and to provide the audience with the best quality picture, but also to avoid the exposure, glare, and brightness reduction of the projection picture caused by ambient light as much as possible. Many consumers are also very worried that the projection equipment will cause problems such as unclear projection pictures when affected by external light.

[0003] In order to solve the above problems, the present invention provides an ultra-short-throw light-guiding structure, which is suitable for the optical path requirements of ultra-short-throw projectors on the market. It can guide light at a large angle to make the light intensity distribution uniform. Its special physical structure design can absorb ambient light and stray light reflected from the surrounding secondary reflections. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides an ultra-short-throw light-guiding structure, which uses optical principles such as refraction, reflection and absorption of light to design a physical structure suitable for the optical path requirements of an ultra-short-throw projector. It can absorb the ambient light around the projection and the stray light reflected by objects for the second time, avoid the influence of ambient light and surrounding stray light on the projection picture, and can also realize large-angle light guiding, which is achieved through the following technical solutions.

[0005] An ultra-short-focus light-guiding structure comprises a reflective structure layer, which is tilted upward or downward, with an inclination angle of ≥18° and less than 42°. The reflective structure layer comprises a plurality of reflective structures, and a duty ratio formed by an aperture size of the reflective structure and a period of the reflective structure layer is ≥0.5 and <1, and a period of the reflective structure layer is ≥50um and ≤300um.

[0006] Furthermore, the thickness of each reflective structure is proportional to the period of the reflective structure layer, and the ratio ranges from ≥0.2 to <1.85.

[0007] Furthermore, the material of the reflective structure layer is a metal material or an inorganic non-metal material with high reflectivity, and the reflectivity is greater than 90%.

[0008] Furthermore, the upper and lower surfaces of each reflective structure have a black light-absorbing coating, the light absorption rate of which is greater than 90%, for absorbing ambient light from the surroundings and stray light secondary reflected from surrounding objects.

[0009] Furthermore, the light guide structure is suitable for front projection or rear projection.

[0010] Furthermore, when the inclination angle of the reflective structure layer is ≥30° and less than 42 degrees, the projection light can be projected from both sides, and the light is guided to the projection surface. The present invention provides an ultra-short-throw light-guiding structure, which is suitable for the optical path requirements of ultra-short-throw projectors currently on the market, can guide light at a large angle, make the light intensity evenly distributed, better absorb the environment and the secondary reflected stray light around, solve the impact of ambient light on the projection picture, and prevent the projection light from being wasted during the projection process to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of the light guide structure layer in a specific embodiment of the present invention.

[0012] Figure 2 The present invention is a schematic diagram of light refraction at an inclined angle.

[0013] Figure 3 The present invention is a schematic diagram of light refraction at another inclined angle. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] like Figure 1 As shown, an ultra-short focus light-guiding structure includes a reflective structure layer 10 and a substrate, wherein the substrate is used to support the reflective structure layer 10, the reflective structure layer 10 is tilted upward or downward, and the tilt angle C is ≥18° and less than 42°. The reflective structure layer 10 includes a plurality of reflective structures 20, and the duty cycle formed by the aperture size B in the reflective structure and the period D of the reflective structure is ≥0.5 and <1, and the period of the reflective structure layer is ≥50um and ≤300um.

[0016] The reflective structures 20 of the reflective structure layer are arranged neatly and present a certain angle. The material of the reflective structure layer is a metal material or an inorganic non-metal material with high reflectivity, and the reflectivity is greater than 90%. The metal material is a general metal material, such as aluminum; the inorganic non-metal material, such as aluminum oxide, needs to have a reflectivity greater than 90%.

[0017] The thickness of each reflective structure 20 of the reflective structure layer 10 is proportional to the period of the reflective structure layer, and the ratio range is ≥0.2 and <1.85. The upper and lower surfaces of each reflective structure have a black light-absorbing coating, and its light absorption rate is greater than 90%, which is used to absorb the ambient light from the surroundings and the stray light A reflected by the surrounding objects.

[0018] The light guide structure of the present invention is suitable for front projection or rear projection, and is a structure capable of projection on both sides.

[0019] like Figure 2-3 As shown, when the inclination angle of the reflective structure layer is ≥30° and less than 42 degrees, the projection light can be projected from both sides and the light is directed to the projection surface.

[0020] Specific reference Figure 2 The projection optics projects from both sides, with the left side being the projection surface, the light 100 on the projection surface, the dark light in the reference figure, and the other side being the light 200, the light light in the reference figure. When the inclination angle of the light guide structure is 30°, the refraction paths of the light 100 and the light 200 are refracted toward the projection surface.

[0021] Specific reference Figure 3 The projection optics projects from both sides, with the left side being the projection surface, the light 100 on the projection surface, the dark light in the reference figure, and the other side being the light 200, the light light in the reference figure. When the inclination angle of the light guide structure is 42°, the refraction paths of the light 100 and the light 200 are refracted toward the projection surface.

[0022] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An ultra-short-focus light guide structure, characterized in that: The invention comprises a reflective structure layer, the reflective structure layer is inclined upward or downward, the reflective structure layer comprises a plurality of reflective structures, the duty ratio formed by the aperture size of the reflective structure and the period of the reflective structure layer is ≥0.5 and <1, the period of the reflective structure layer is ≥50um and ≤300um, the thickness of each reflective structure is proportional to the period of the reflective structure layer, and the ratio range is ≥0.2 and <1.85; The upper and lower surfaces of each reflective structure have a black light-absorbing coating with a light absorption rate greater than 90%, which is used to absorb the ambient light from the surroundings and the stray light reflected by the surrounding objects. When the inclination angle of the reflective structure layer is ≥30 degrees and less than 42 degrees, the projection light can be projected from both sides and the light is directed to the projection surface.

2. The light guide structure according to claim 1, characterized in that: The material of the reflective structure layer is a metal material or an inorganic non-metal material with high reflectivity, and the reflectivity is greater than 90%.

3. The light guide structure according to claim 1, characterized in that: The light guide structure is suitable for front projection or rear projection.

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