Total reflection lens, optical projection system and projection ray machine

Abstract

The invention discloses a total reflection lens (200), an optical projection system (10) and a projection ray machine. The total reflection lens (200) comprises a collimation part (210) and a beam expanding part (220), the auto-collimation part (210) points to the direction of the beam expanding part (220), and the sectional dimension of the auto-collimation part (210) is increased; at the connecting position of the collimation part (210) and the beam expanding part (220), the cross-sectional area of the total reflection lens (200) changes suddenly, and the cross-sectional area of the collimation part (210) is larger than that of the beam expanding part (220). Light emitted by the light-emitting light source (100) is collimated through the collimation part (210), and the collimated light enters the beam expanding part (220) to be expanded. The large-size beam expanding part (220) can receive the small-angle deflected light existing at the edge and shape the deflected light and the collimated light together.

Description

Total reflection lens, optical projection system and projection light machine Technical Field

[0001] The present invention belongs to the field of projection display, and in particular relates to a total reflection lens, an optical projection system and a projection optical machine. Background Art

[0002] Projection technology originated in the early 19th century and was popularized based on the invention and popularity of movies in the late 19th and early 20th centuries. The light emitted by the luminous light source is processed and then projected onto a display screen for projection display.

[0003] However, in the existing projection light machine, it is impossible to effectively shape the light emitted by the light source, resulting in low energy utilization efficiency.

[0004] Summary of the Invention

[0005] In response to the shortcomings of existing methods, this application proposes a total reflection lens, an optical projection system and a projection light engine, which can effectively improve energy utilization.

[0006] According to a first aspect of an embodiment of the present invention, there is provided a total reflection lens, the total reflection lens comprising a collimating portion and a beam expanding portion;

[0007] From the direction from the collimating portion to the beam expanding portion, the cross-sectional size of the collimating portion increases;

[0008] At a connection position between the collimating portion and the beam expanding portion, the cross-sectional area of ​​the total reflection lens suddenly changes, and the cross-sectional area of ​​the collimating portion is greater than the cross-sectional area of ​​the beam expanding portion.

[0009] Furthermore, at the connection position between the collimating portion and the beam expanding portion, the minimum distance from the edge of the collimating portion to the edge of the beam expanding portion is a first distance, and the first distance is greater than or equal to 0.5 mm and less than or equal to 2 mm.

[0010] Furthermore, the peripheral wall of the collimating portion is in an outwardly protruding arc shape.

[0011] Furthermore, the collimating portion includes a first surface away from the beam expanding portion, and extends inwardly from the first surface to form a concave light entrance cavity;

[0012] From the direction from the collimating portion to the beam expanding portion, the cross-sectional area of ​​the light incident cavity gradually decreases.

[0013] Furthermore, the light incident cavity includes side walls and a top wall, and the slopes corresponding to various positions of the side walls are the same; and / or,

[0014] The top wall protrudes in a direction away from the beam expansion portion and is arc-shaped.

[0015] Furthermore, the ratio of the depth of the light incident cavity to the height of the collimating portion is greater than or equal to 1 / 5 and less than or equal to 1 / 2.

[0016] Furthermore, the beam expander includes a light emitting surface away from the collimating portion;

[0017] In the first plane, the edge area of ​​the light emitting surface is convex compared to the central area; in the second plane, the edge area of ​​the light emitting surface is convex compared to the central area; the first plane and the second plane form an angle;

[0018] The first plane and the second plane are both parallel to a connecting direction of the collimating portion and the beam expanding portion.

[0019] Furthermore, the first plane and the second plane are perpendicular, and the number of the protrusions is four.

[0020] According to a second aspect of an embodiment of the present invention, there is provided an optical projection system, wherein the optical projection system includes a total reflection lens, and the number of the total reflection lenses is plural.

[0021] Furthermore, the optical projection system further comprises a heat-insulating glass, and the heat-insulating glass is arranged near the beam expansion portion of the total reflection lens;

[0022] Each of the total reflection lenses includes a light entrance cavity extending inward from the collimating portion away from the beam expanding portion to form a concave light entrance cavity; the light entrance cavity includes side walls and a top wall; a light spot formed on the heat-insulating glass by light sequentially passing through the side walls of the light entrance cavity and the peripheral wall of the collimating portion is used as a secondary light spot; a light spot formed on the heat-insulating glass by light passing through the top wall of the light entrance cavity is used as a primary light spot;

[0023] At least part of the structures of the auxiliary light spots formed by adjacent total reflection lenses overlap.

[0024] Furthermore, the distance between adjacent total reflection lenses is greater than or equal to 0.05 mm and less than or equal to 5 mm.

[0025] According to a third aspect of an embodiment of the present invention, a projection light engine is provided. The projection light engine includes a housing and an optical projection system. The optical projection system is located inside the housing.

[0026] The beneficial technical effects brought about by the technical solutions provided by the embodiments of the present application are:

[0027] The total reflection lens, optical projection system, and projection light engine provided in the embodiments of the present application collimate the light emitted by the luminous light source through the collimating part, and the collimated light enters the beam expansion part for beam expansion. However, after the light is collimated, a small amount of deflected light with a small angle will still exist at the edge. A larger beam expansion part is used to receive the deflected light, and the deflected light and the collimated light are shaped together to increase the brightness of the subsequent light spot, thereby improving energy utilization. At the same time, the deflected light is prevented from entering the adjacent total reflection lens, thereby avoiding affecting the optical display effect of other areas.

[0028] Additional aspects and advantages of the present application will be given in part in the following description, which will become apparent from the following description, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0030] FIG1 is a schematic structural diagram of an optical projection system according to an embodiment of the present application.

[0031] FIG2 is a schematic structural diagram of an optical projection system.

[0032] FIG. 3 is a schematic diagram of a light path simulation effect of part of the light in the reflective cup in FIG. 2 .

[0033] FIG4 is a schematic structural diagram of another optical projection system.

[0034] FIG. 5 is a schematic diagram of a light path simulation effect of part of the light in the plane convex lens in FIG. 4 .

[0035] FIG. 6 is a schematic diagram showing a light path simulation effect of part of the light in a total reflection lens according to an embodiment of the present application.

[0036] FIG. 7 is a schematic diagram of a simulated light spot corresponding to a total reflection lens according to another embodiment of the present application.

[0037] FIG8 is a schematic diagram of a simulated light spot corresponding to a total reflection lens according to another embodiment of the present application.

[0038] FIG9 is a schematic diagram of a simulated light spot corresponding to a total reflection lens according to another embodiment of the present application.

[0039] FIG10 is a schematic diagram of a simulated light spot corresponding to a total reflection lens according to another embodiment of the present application.

[0040] FIG. 11 is a schematic diagram of a simulated light spot corresponding to a total reflection lens according to an embodiment of the present application.

[0041] FIG12 is a schematic structural diagram of a total reflection lens according to an embodiment of the present application.

[0042] FIG13 is another schematic structural diagram of a total reflection lens according to an embodiment of the present application.

[0043] FIG. 14 is a schematic diagram of another simulated light spot corresponding to the total reflection lens according to an embodiment of the present application.

[0044] FIG15 is another schematic diagram of a simulated light spot corresponding to the total reflection lens according to an embodiment of the present application.

[0045] FIG16 is a schematic diagram of a simulated light spot corresponding to another total reflection lens of the present application.

[0046] FIG17 is a schematic diagram of a simulated light spot corresponding to another total reflection lens of the present application.

[0047] FIG18 is a diagram showing the illumination energy distribution of a light spot corresponding to an optical projection system.

[0048] FIG19 is a schematic structural diagram of some optical components in an optical projection system according to another embodiment of the present application.

[0049] FIG20 is a diagram showing the illumination energy distribution of a light spot corresponding to another optical projection system.

[0050] FIG21 is a diagram showing the illumination energy distribution of a light spot in an optical projection system according to an embodiment of the present application.

[0051] FIG22 is a diagram showing the illumination energy distribution of a light spot corresponding to an optical projection system according to an embodiment of the present application.

[0052] FIG23 is a light distribution curve diagram of a total reflection lens according to an embodiment of the present application.

[0053] DESCRIPTION OF REFERENCE NUMERALS Optical projection system 10 Light source 100 Insulating glass 300 Total reflection lens 200 Collimating portion 210 Peripheral wall 211 First surface 212 Light incident cavity 213 Side wall 214 Top wall 215 Beam expander 220 Light exit surface 221 Optical module 400 Fresnel lens 500 Reflector 600 Imaging lens 700 Reflection cup 810 Auxiliary Fresnel lens 820 Planar convex lens 830 Platform 831 Auxiliary reflector 840 Light spot 900 Main light spot 910 Auxiliary light spot 920 Light exit direction X Connection position M First distance d1 DETAILED DESCRIPTION

[0054] The present application is described in detail below. Examples of embodiments of the present application are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar components or components having the same or similar functions. In addition, if the detailed description of the known technology is not necessary for the features of the present application shown, it will be omitted. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0055] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0056] Those skilled in the art will understand that, unless otherwise stated, the singular forms "a," "an," "said," and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of this application refers to the presence of the stated features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0057] The present application discloses a projection light machine comprising a housing and an optical projection system, wherein the optical projection system is located inside the housing.

[0058] As shown in FIG. 1 , the optical projection system 10 includes a light source 100 , a shaping lens, a heat-insulating glass 300 , an optical module 400 , a Fresnel lens 500 , a reflector 600 , and an imaging lens 700 .

[0059] Light emitted from light source 100 is directly shaped by the shaping lens, which collimates and expands the light. Light emitted from total reflection lens 200 passes through thermal insulation glass 300 and optical module 400 to achieve a multi-color display. It then converges through Fresnel lens 500 to align with imaging lens 700. Light emitted from Fresnel lens 500 is incident on reflector 600 to redirect the light path, and finally passes through the imaging lens to project a color image onto the screen.

[0060] The light source 100 can be an LED, and the optical module 400 is an LCD liquid crystal module. The LCD module includes a first electrode, a second electrode, and a liquid crystal layer sandwiched between them. By controlling the voltage applied to the first and second electrodes, the deflection square of the liquid crystal molecules in the liquid crystal layer is controlled, thereby controlling the brightness and direction of the emitted light. The LCD module also includes a color filter. Furthermore, polarizers with different polarization directions are respectively installed on the end of the insulating glass 300 away from the shaping lens and the end of the optical module 400 away from the shaping lens.

[0061] It should be noted that the “shaping” mentioned here includes collimating and expanding the light.

[0062] As shown in Figures 2 and 3 , in one design, the shaping lens combines a reflector cup 810 and an auxiliary Fresnel lens 820. Specifically, the reflector cup 810 reflects light emitted by the light source 100. The light emitted from the reflector cup 810 first passes through the auxiliary Fresnel lens 820 for shaping and focusing, resulting in nearly parallel light. The light then passes through the insulating glass 300 and illuminates the back of the optical module 400. It then passes through the Fresnel lens 500, the reflector 600, and the imaging lens 700, sequentially, to form a projection image on a screen several meters away. The light path is shown by the arrows in the figure.

[0063] However, in this design, the reflector cup 810 is a hollow structure that can only reflect high-angle light emitted by the light source 100. Specifically, low-angle light emitted by the light source 100 directly exits the reflector cup 810 and passes through subsequent optical components such as the auxiliary Fresnel lens 820. High-angle light emitted by the light source 100 is reflected by the sidewalls 214 of the reflector cup 810 to achieve collimation (see Figure 3). The reflected light exits the reflector cup 810 and passes through subsequent optical components such as the auxiliary Fresnel lens 820. It should be noted that Figure 3 is a schematic diagram of the optical path simulation effect of a portion of the light in the reflector cup 810.

[0064] Based on the above analysis, it can be seen that in the scheme shown in Figures 2 and 3, in the scheme of using the combination of the reflector cup 810 and the auxiliary Fresnel lens 820 to shape the light, only the large-angle light 11 can be collimated, and the small-angle light 12 cannot be collimated. At this time, the angle of the small-angle light 12 is not changed. Some of the small-angle light 12 cannot be directly reflected by the reflector cup 810 and emitted directly through the auxiliary Fresnel lens 820 to the back of the optical module 400 (the side close to the light source). Instead, it is easily converted into stray light and absorbed by the housing of the projector. As a result, this part of the light cannot be effectively utilized, affecting the light output efficiency of the projection and causing the housing and components to overheat. At the same time, the manufacturing process of the auxiliary Fresnel lens 820 is complex and costly. In other words, using the combination of the reflector cup 810 and the auxiliary Fresnel lens 820 cannot collimate all the light, and the process is difficult and costly.

[0065] As shown in Figures 4 and 5 , in another design, the shaping lens is a combination of a planar convex lens 830, an auxiliary reflector 840, and an auxiliary Fresnel lens 820'. Specifically, the planar convex lens 830 can refract light emitted by a light source (not shown). The light emitted by the light source (not shown) enters through the plane of the planar convex lens 830 and is refracted by the convex surface of the planar convex lens 830. After that, the light path is changed by the auxiliary reflector 840. The light with the changed light path enters the auxiliary Fresnel lens 820' for focusing, obtaining nearly parallel light. The light then passes through the insulating glass 300 and irradiates the back of the optical module 400. The light then passes through the Fresnel lens 500, the reflector 600, and the imaging lens 700 in sequence, and is projected onto a screen several meters away to form a projection image.

[0066] However, in this design, the plane convex lens 830 can only effectively refract the small-angle light 12' emitted by the luminous light source 100 (see Figure 5). Specifically, the small-angle light 12' emitted by the luminous light source 100 is emitted through the convex surface of the plane convex lens 830 and passes through the subsequent optical components such as the reflector 600 and the auxiliary Fresnel lens 820' in sequence, and reaches the back of the optical module 400 (close to the side of the luminous light source). The large-angle light 11' emitted by the luminous light source 100 reaches the surface of the plane convex lens 830 at a relatively small inclination. At the same time, due to the large inclination angle of the light itself, it is impossible to achieve good collimation. Even some of the light with a larger angle will be directly emitted outward through the platform 831 below the plane convex lens 830 to form stray light. At this time, after the large-angle light is emitted from the plane convex lens 830, it cannot pass through the subsequent optical components such as the auxiliary Fresnel lens 820' to reach the back of the optical module 400 (close to the side of the luminous light source), and eventually becomes stray light. It should be noted that FIG5 is a schematic diagram of the light path simulation effect of part of the light in the planar convex lens 830.

[0067] Based on the above analysis, in the schemes shown in Figures 4 and 5, the combination of the reflector cup 810 and the auxiliary Fresnel lens 820' is used to shape the light. This can only collimate the small-angle light 12', but cannot collimate the large-angle light 11'. At this time, the small-angle light 12' cannot pass directly through the auxiliary Fresnel lens 820' through the refraction of the flat convex lens 830, and is easily converted into stray light and absorbed by the housing of the projector. As a result, this part of the light cannot be effectively utilized, affecting the light output efficiency of the projection, and at the same time, causing the temperature of the housing and components to be too high. On the other hand, in the schemes shown in Figures 4 and 5, there are many optical components involved in the shaping lens. With each optical component passed through, the efficiency will decrease, the risk of stray light will increase, and the cost will inevitably increase.

[0068] In response to the problems of the above scheme, the inventors designed the following scheme:

[0069] As shown in Figures 1 and 6, the overall lens adopts a total reflection lens 200 (TIR lens), and the total reflection lens 200 includes a collimating part 210 and a beam expanding part 220. The heat-insulating glass 300 is arranged near the beam expanding part 220 of the total reflection lens 200. The peripheral wall 211 of the collimating part 210 is arranged at an angle. That is, from the direction of the collimating part 210 pointing to the beam expanding part 220 (the light emitting direction X of the total reflection lens 200), the cross-section of the collimating part 210 gradually increases. The inclined peripheral wall 211 is used to refract and reflect the large-angle light 11" emitted by the light source 100. In other words, the large-angle light 11" is mixed by refraction and reflection in the total reflection lens 200, and then forms a uniformly distributed light on the light emitting surface 221 of the light source 100 and is emitted, and reaches the subsequent optical components such as the heat-insulating glass 300 and the optical module 400 in turn. The collimating portion 210 also includes a curved surface facing the light source 100 (such as the top wall 215 shown below) to effectively refract the small-angle light 12" emitted by the light source 100. In other words, the small-angle light 12" is directly refracted and emitted through the central part of the total reflection lens 200, and reaches the subsequent optical components such as the insulating glass 300 and the optical module 400 in turn. Through the above-mentioned collimating portion 210, the large-angle light 11" and the small-angle light 12" emitted by the light source 100 can be effectively collimated to avoid or reduce the light from becoming stray light and reduce unnecessary energy loss. The expanding portion 220 includes a light-emitting surface 221 away from the collimating portion 210, and the light-emitting surface 221 is at least partially curved to expand the light emitted from the collimating portion 210 and form an expected light spot.

[0070] It should be noted that FIG6 is a schematic diagram showing the simulation effect of a portion of the light path in the total reflection lens 200 .

[0071] In the above embodiment, not only is light utilization improved, but the use of auxiliary Fresnel lens 820 can also be eliminated, reducing process difficulty and effectively controlling costs. Furthermore, reducing the use of optical components can further improve light utilization, further reduce the occurrence of stray light, and further reduce costs.

[0072] In this embodiment, the specific shape of the light emitting surface 221 can be obtained using the following formula: Chirp = 1 + (Corner - 1) × D Factor

[0073] Chirp is the thickness of the beam expander 220 at fixed coordinates, that is, the vertical thickness from the light-emitting surface 221 to the beam expander 220 at fixed coordinates. D is the distance from the beam expander 220 to the insulating glass 300 at fixed coordinates, that is, the distance from the light-emitting surface 221 to the insulating glass 300 at fixed coordinates. Corner is the angle option (hereinafter referred to as "Angle (c)"), and Factor is the coefficient (F). Both can be adjusted according to actual conditions. For a total reflection lens 200, both Angle (c) and Factor (F) are fixed values.

[0074] The brightness of the light spot can be adjusted by adjusting the values ​​of the angle (c) and the coefficient (F).

[0075] The inventors have found that when the coefficient (F) is fixed, the position of the brighter area of ​​the light spot can be changed by adjusting the angle (c). The following is a simple example:

[0076] When the value of angle (c) is 2 and the coefficient (F) is 2, the illumination energy distribution of the light spot is shown in Figure 7. The brightness of the center of the light spot is low, and the brightness of the surrounding area is high.

[0077] When the angle (c) is 0.5 and the coefficient (F) is 2, the illumination energy distribution of the light spot is shown in Figure 8. The brightness of the center of the light spot is high, and the brightness of the surrounding area is low.

[0078] The inventors have found that when the angle (c) is fixed, the uniformity of the spot brightness can be changed by adjusting the coefficient (F). Specifically, when the value of the coefficient (F) becomes larger, the uniformity of the spot brightness improves. The following is a simple example:

[0079] When the angle (c) is 2 and the coefficient (F) is 7, the illumination energy distribution of the spot is shown in Figure 9. The brightness at the center of the spot is low, while the brightness at the periphery is high. Furthermore, the brightness of the spot is relatively uniform, with a larger area of ​​relatively low brightness at the center and smaller areas of relatively high brightness at the periphery.

[0080] When the angle (c) is 2 and the coefficient (F) is 1, the illumination energy distribution of the spot is shown in Figure 10. The brightness at the center of the spot is low, while the brightness at the periphery is high. Furthermore, the brightness of the spot is uneven, with a relatively small area of ​​low brightness at the center and a larger area of ​​high brightness at the periphery.

[0081] Through numerous experiments, the inventors have discovered that the ideal light spot is formed when the angle (c) is 1 and the coefficient (F) is 2. The corresponding illumination energy distribution diagram of the light spot is shown in FIG11 .

[0082] The inventors discovered through experiments that by changing the relative shapes of the beam expander 220 and the collimator 210, it is possible to effectively solve the problem that when the connection between the collimator 210 and the beam expander 220 is the same size and has a smooth transition, some light leaks out of the collimator 210 without passing through the beam expander 220, and eventually forms stray light that is absorbed by the housing of the projection light machine, causing energy waste.

[0083] Specifically, as shown in Figures 12 and 13, and in combination with Figure 6 if necessary, in this embodiment, the cross-sectional dimensions of the collimating portion 210 increase as the collimating portion 210 points toward the beam expander 220, i.e., the light emitting direction X of the total reflection lens 200, to achieve effective reflection of large-angle light in all directions. At the connection position M between the collimating portion 210 and the beam expander 220, the cross-sectional area of ​​the total reflection lens 200 undergoes a sudden change, i.e., the dimensions of the connection position between the collimating portion 210 and the beam expander 220 suddenly change, and the cross-sectional area of ​​the collimating portion 210 is larger than the cross-sectional area of ​​the beam expander 220.

[0084] In the above arrangement, the light emitted by the light source 100 is collimated by the collimating portion 210, and the collimated light enters the beam expander 220 for beam expansion. Among the light emitted from the collimating portion 210, a small amount of deflected light with a small angle (about 3°) will still exist at the edge. The larger beam expander 220 is used to receive the deflected light and shape the deflected light and the collimated light together (see Figure 6) to improve the brightness of the subsequent light spot, avoid or reduce the appearance of stray light, improve the light effect, reduce unnecessary heat generation, and improve the efficiency of the entire device. At the same time, when there are multiple total reflection lenses 200 in the optical projection system 10, the above arrangement can also prevent the deflected light emitted from one total reflection lens 200 from entering the adjacent total reflection lens 200, thereby avoiding affecting the optical display effect of other areas.

[0085] Through a large number of experiments, the inventors found that by precisely controlling the minimum distance from the edge of the collimating part 210 to the edge of the beam expanding part 220 at the connection position M between the collimating part 210 and the beam expanding part 220, the problems of the beam expanding part 220 being unable to receive sufficient deflected light, the total reflection lens 200 occupying too large an area, and the appearance of dark spots between two adjacent light spots can be effectively solved.

[0086] Specifically, at the connection point M between the collimating portion 210 and the beam expander 220, the minimum distance between the edge of the collimating portion 210 and the edge of the beam expander 220 is set to a first distance d1. When the first distance d1 is greater than or equal to 0.5 mm, a larger amount of deflected light emitted by the collimating portion 210 can be received, allowing more light to be shaped and improving light utilization. When the first distance d1 is less than or equal to 2 mm, the total reflection lens 200 occupies an appropriate area, facilitating a compact design of the entire device. Furthermore, when the optical projection system 10 includes multiple total reflection lenses 200, controlling the first distance d1 within 2 mm effectively reduces or prevents the occurrence of dark spots between adjacent light spots. In other words, when the first distance d1 is within the above range, a large amount of deflected light can be shaped, improving light utilization and facilitating overall device miniaturization. In this embodiment, the first distance d1 is 1 mm.

[0087] Furthermore, the peripheral wall 211 of the collimating portion 210 is in the shape of an arc protruding outward. Compared with the inclined structure with a single slope, the slope of each position of the arc can be appropriately adjusted according to the actual light emission of the light source 100 and the collimation and expansion of the light by the total reflection lens 200, thereby achieving the refraction, reflection and collimation of as many large-angle light rays as possible, thereby improving the utilization efficiency of the optical projection system 10 of the light emitted by the light source 100 and reducing unnecessary energy waste.

[0088] As shown in Figure 12, the collimating portion 210 includes a first surface 212 away from the beam expanding portion 220. A concave light entrance cavity 213 is formed by extending inward from the first surface 212, and the cross-sectional area of ​​the light entrance cavity 213 gradually decreases in the direction from the collimating portion 210 to the beam expanding portion 220 (the light emitting direction X). In other words, the light entrance cavity 213 includes side walls 214 and a top wall 215. Along the light emitting direction X, the side walls 214 of the light entrance cavity 213 gradually narrow. The side walls 214 are used to receive large-angle light emitted by the light source 100, and allow the large-angle light to enter the total reflection lens 200 by refraction, and then be reflected by the peripheral wall 211 of the collimating portion 210, and finally be expanded by the beam expanding portion 220. The entire process realizes the refraction and reflection of large-angle light (refer to the optical path shown in Figure 6).

[0089] The slope of each position of the peripheral wall 211 can be derived by formula, and the specific formula is as follows: y 5,t+1 =P 5,t (x 5,t+1 -x 5,t )+y 5,t

[0090] The 5 in the subscript represents the light emitted from the light emitting surface 221. 5,t+1Indicates the x coordinate corresponding to the t+1th light ray emitted from the light emitting surface 221. 5,t y represents the x-coordinate corresponding to the t-th light ray emitted from the light-emitting surface 221. 5,t represents the y-coordinate corresponding to the t-th light ray emitted from the light-emitting surface 221 .

[0091] 4 represents the light reflected from the peripheral wall 211 and not emitted from the light emitting surface 221. Specifically, y 4,t+1 Indicates the y coordinate corresponding to the t+1th light ray reflected from the peripheral wall 211. 4,t+1 represents the x-coordinate corresponding to the t+1th light ray reflected from the peripheral wall 211 .

[0092] P represents the angle between the light emitted from the self-luminous light source 100 and the vertical axis before entering the total reflection lens 200. Specifically, P 5,t represents the angle between the t-th light ray emitted from the light emitting surface 221 and the vertical axis before entering the total reflection lens 200. m represents the slope of the light ray transmitted from the side wall 214 but not reflected from the peripheral wall 211. Specifically, m 4,t+1 It represents the slope of the light corresponding to the t+1th light reflected from the peripheral wall 211 , which is transmitted from the side wall 214 but not reflected from the peripheral wall 211 .

[0093] In this embodiment, the slope of a portion 2111 of the peripheral wall 211 that is close to the first surface 212 (i.e., close to the light source) is smaller than the slope of a portion 2112 that is distant from the first surface 212. This arrangement allows the portion 2111 of the peripheral wall 211 that is distant from the first surface 212 to collimate light rays with relatively large angles, while allowing the portion 2112 of the peripheral wall 211 that is distant from the first surface 212 to collimate light rays with relatively small angles. Furthermore, in this embodiment, the corresponding slopes at various locations on the sidewall 214 are the same. This structure can be easily obtained through an injection molding process or secondary processing, which can help reduce process costs and improve process efficiency.

[0094] Specifically, in this embodiment, the slope of a portion 2111 of the peripheral wall 211 close to the first surface 212 (i.e., close to the light source) is 1.0677. The slope of the middle region of the peripheral wall 211 is 1.6511. The slope of a portion 2111 of the peripheral wall 211 away from the first surface 212 (i.e., close to the light source) is 2.4518.

[0095] The top wall 215 is the curved surface facing the light source 100 mentioned above. It bulges away from the beam expander 220 and has an arc shape (preferably a hemispherical shape). The top wall 215 is used to receive small-angle light emitted by the light source 100. After being refracted at this position, the small-angle light is directed into the collimating section 210 and the beam expander 220 to refract the small-angle light and achieve collimation and expansion of the light.

[0096] With reference to Figures 12 to 14 , the distinction between large-angle light and small-angle light is as follows: in the present application, the light emitted by the self-luminous light that reaches the top wall 215 of the light-entering cavity 213 is regarded as the small-angle light, and the light emitted by the self-luminous light that reaches the side wall 214 of the light-entering cavity 213 is regarded as the large-angle light. Of course, it can also be understood that the light that has only been refracted is regarded as the small-angle light, and the light that has been refracted is regarded as the large-angle light. At the same time, the optical path of the small-angle light in the total reflection lens 200 is shorter, and the light spot formed on the insulating glass 300 after passing through the total reflection lens 200 is regarded as the main light spot 910. In other words, the light spot formed on the insulating glass 300 by the light passing through the top wall 215 of the light-entering cavity 213 is regarded as the main light spot 910. Since the optical path of this part of the light is shorter, the brightness of the main light spot 910 is greater. High-angle light rays travel a longer optical path through the total reflection lens 200, and the light spot formed on the insulating glass 300 after passing through the total reflection lens 200 is referred to as the secondary light spot 920. In other words, the light spot formed on the insulating glass 300 by the light rays sequentially passing through the sidewalls 214 of the light entrance cavity 213 and the peripheral wall 211 of the collimating portion 210 is referred to as the secondary light spot 920. Due to the longer optical path of this portion of light, the brightness of the secondary light spot is lower. The brightness of the primary light spot 910 is greater than that of the secondary light spot 920, and the brightness of the primary light spot 910 is typically greater than 50%, while the brightness of the secondary light spot 920 is typically greater than 10%.

[0097] It should be noted that Figure 14 is a schematic diagram of a simulated light spot formed by the total reflection lens 200 on the insulating glass. The rectangular structure in the figure is the light spot, the inner circle is the main light spot 910, and the outer circle is the secondary light spot 920. In addition, the circular structure in the center is the projection of the total reflection lens 200 on the insulating glass.

[0098] The inventors have found through numerous experiments that when the ratio of the depth of the light incident cavity 213 to the height of the collimating portion 210 is controlled within an appropriate range, the problems of excessive brightness difference between the main light spot 910 and the auxiliary light spot 920, greater process difficulty, and poor collimation effect can be solved.

[0099] Specifically, when the depth of the light incident cavity 213 is increased, the amount of light entering the total reflection lens 200 through the top wall 215 becomes less, and the area of ​​the main light spot 910 becomes smaller. Correspondingly, the amount of light entering the total reflection lens 200 through the side wall 214 becomes more, and the area of ​​the secondary light spot 920 becomes larger. When the ratio of the depth of the light incident cavity 213 to the height of the collimating portion 210 is greater than or equal to 1 / 5, the difference in brightness at the junction of the main light spot 910 and the secondary light spot 920 is small, which is beneficial to improving the uniformity of the picture. When the ratio of the depth of the light incident cavity 213 to the height of the collimating portion 210 is less than or equal to 1 / 2, the problem of the large lifting process caused by the excessive depth of the light incident cavity 213 and the short path of part of the light emitted by the light source 100 in the total reflection lens 200 affecting the collimation effect can be avoided. A better collimation effect is guaranteed. In other words, when the ratio of the depth of the light incident cavity 213 to the height of the collimating portion 210 is within the above range, it can ensure that the proportion of the main light spot 910 and the auxiliary light spot 920 is within an appropriate range, thereby improving the uniformity of the image. At the same time, it can ensure that the light is effectively collimated and expanded, and the cost can be controlled within an appropriate range.

[0100] Specifically, in this embodiment, when the depth of the light incident cavity 213 is 6.5 mm, that is, when the distance between the light emitting surface of the light source and the top wall 215 of the total reflection lens 200 is 6.5 mm, the light spot illumination distribution diagram is shown in FIG15 .

[0101] When the depth of the light incident cavity 213 is 7 mm, that is, when the distance between the light emitting surface of the light source and the top wall 215 of the total reflection lens 200 is 7 mm, the light spot is as shown in FIG. 16 .

[0102] When the depth of the light incident cavity 213 is 10 mm, that is, when the distance between the light emitting surface of the light source and the top wall 215 of the total reflection lens 200 is 10 mm, the light spot is as shown in FIG. 17 .

[0103] It can be seen that as the distance increases, the spot image is distorted and the stratification of the main spot and the auxiliary spot becomes more and more serious. In this application, a structure in which the depth of the light incident cavity 213 is 6.5 mm is adopted.

[0104] The design of a total reflection lens 200 and a light source 100 is adopted. If the entire screen needs to be covered, a light source 100 with higher power and a total reflection lens 200 with larger size, especially a total reflection lens 200 with higher height, is required. This will seriously limit the thickness of the whole machine. At the same time, the design of a single light source 100 will cause excessive concentration of heat, and higher requirements are placed on the temperature resistance of each optical device. On the other hand, the light spot generated by this solution is a light spot formed by a single total reflection lens 200 and a light source 100. The illuminance energy distribution diagram of the light spot is shown in Figure 18. The illuminance energy in the central area is larger, and the illuminance energy in the edge area is smaller. The overall illumination energy presented by the light spot is uneven, and the subsequent projection picture will inevitably have the problem of uneven picture brightness.

[0105] As shown in Figure 19, in this embodiment, the optical projection system 10 includes multiple total reflection lenses 200 and multiple light sources 100. Each light source 100 and total reflection lens 200 is arranged in a one-to-one correspondence. The multiple light sources 100 are placed flush with each other, and the multiple total reflection lenses 200 are also placed flush with each other to ensure that the light entrance surface (first surface 212) and the light exit surface 221 are at the same level. Increasing the number of light sources 100 effectively reduces the power of each light source 100 and the height of each total reflection lens 200. Multiple light sources 100, combined with multiple total reflection lenses 200, enable luminous displays in different areas. This arrangement effectively shortens the optical path and avoids energy waste. Furthermore, it avoids the use of expensive, high-power light sources 100 and allows the use of other optical components with relatively lower temperature tolerance requirements, effectively reducing costs and avoiding or minimizing heat generation issues. In other words, it achieves high light efficiency, low power consumption, and a compact size.

[0106] If the multiple total reflection lenses 200 and the light sources 100 in the optical projection system 10 are simply arranged, the illumination energy distribution diagram of the obtained light spots is shown in FIG20 , and dark lines appear between adjacent light spots.

[0107] As shown in Figures 20, 21, and 22, if at least part of the structure of the secondary light spots formed by adjacent total reflection lenses 200 is overlapped, the brightness of the secondary light spot area can be reduced, the uniformity of the image can be improved, and the appearance of dark lines can be avoided. Through the above setting, the secondary light spots with lower brightness can be superimposed on each other to obtain an area with higher brightness. The brightness of the superimposed area is equivalent to that of the main light spot area, thereby improving the uniformity of the entire image. Through the above setting, the problem of low edge energy caused by a single light source is solved, and through the energy compensation method, high uniformity of the entire image is achieved.

[0108] It should be noted that Figure 21 shows the illuminance energy distribution of the light spot corresponding to a single total reflection lens 200 after at least partial overlap of adjacent secondary light spots. Figure 22 shows the illuminance energy distribution of the overall light spot formed by multiple total reflection lenses 200 on the insulating glass. This overall light spot is formed by superimposing the individual light spots formed by multiple single total reflection lenses 200. The illuminance energy in the central area is close to that in the edge areas, achieving a uniform transition, resulting in better brightness uniformity in the subsequent projected image.

[0109] Furthermore, the overlapping area of ​​the auxiliary light spot needs to be considered according to the actual situation. For example, when the brightness of the outer edge of the main light spot is 1500 lumens, the brightness of the auxiliary light spot close to the main light spot is

[0110] When the luminance is 1000 lumens, all the secondary light spot areas cannot be directly superimposed, otherwise the brightness of the light surface will change suddenly. It is necessary to ensure that the brightness of the superimposed area and the brightness of the non-superimposed area have a smooth transition trend. The distance between the adjacent total reflection lenses 200 and the corresponding light sources 100 is used to change the corresponding light spot range and make the edges of the two light spot areas overlap. In the illuminance energy diagram, if the energy at the edge seam can achieve a uniform transition, it can be said that the energy at the edge has been improved.

[0111] While controlling the superposition of the secondary light spots, it is necessary to avoid interference between adjacent total reflection lenses 200 and problems of being too close. Specifically, if the distance between adjacent total reflection lenses 200 is too small, it is easy for light located in the total reflection lens 200 to crosstalk into the adjacent total reflection lens 200, thereby affecting the display effect. If the distance between adjacent total reflection lenses 200 is too large, it is easy for dark spots to appear between the light spots formed by the entirety of the adjacent light sources 100 and the total reflection lenses 200. At the same time, if the distance between the total reflection lenses 200 is too large, it also affects the size and overall brightness of the entire device.

[0112] Through a large number of experiments, it was found that when the distance between adjacent total reflection lenses 200 is greater than or equal to 0.05 mm and less than or equal to 5 mm, the above-mentioned problems can be better balanced, which can avoid the crosstalk problem of light in adjacent total reflection lenses 200, effectively avoid the appearance of dark spots, and realize the miniaturization of the entire machine.

[0113] It should be noted that in other embodiments, the curvature of the light-emitting surface 221, the peripheral wall 211 and the top wall 215 of the total reflection lens 200 can be adjusted through optimization calculation to adjust the ratio of the main light spot and the secondary light spot in the light spot formed by a single total reflection lens 200 to eliminate dark spots (see Figures 12 and 13).

[0114] Furthermore, current user requirements for projected images are rectangular, so it is necessary to ensure that the light spot formed by a set of light sources and a total reflection lens is as rectangular or quasi-rectangular as possible. The inventors have discovered that the shape of the light spot can be controlled by controlling the shape of the light-emitting surface.

[0115] As shown in Figures 12 and 13, and as needed in Figure 14, in this embodiment, within the first plane H, the edge region of the light exit surface 221 is raised compared to the center region. Within the second plane I, the edge region of the light exit surface 221 is raised compared to the center region. The first plane H and the second plane I form an angle of 90°; in other words, the first plane H and the second plane I are perpendicular to each other. Furthermore, the first plane H and the second plane I are parallel to the line connecting the collimating portion 210 and the beam expander 220. In the above configuration, the light exit surface 221 has four protrusions, and these four protrusions are evenly distributed along the edge region of the light exit surface 221. This results in a rectangular light spot 900 formed on the insulating glass 300, better suiting the user's desired projection image shape. Compared to the design using a Fresnel lens 500 (see Figures 2 and 4), the edge profile of the Fresnel lens 500 cannot be adjusted to the shape of the projection image, thus affecting the quality of the image at the edge of the projection image. In this application, the shape of the light-emitting surface 221 can be directly changed according to actual needs to adjust the shape of the light spot 900, thereby improving the imaging quality at the edge of the projected image. In this case, the light distribution curve on the total reflection lens 200 is shown in Figure 23. The two curves in Figure 23 represent the light distribution curves at the 0° and 90° positions, respectively.

[0116] Of course, in other embodiments, the angle between the first plane H and the second plane I can also be any angle. For distance description, if the shape of the light spot to be formed on the insulating glass 300 is a triangle, the number of protrusions on the light emitting surface 221 is 3. At this time, the angle between the first plane H and the second plane I is 60°, and one of the three protrusions falls into the first plane H and the second plane I at the same time.

[0117] It should be noted that the light emitting surface 221 may be a free-form surface, and the depth of the concave portion of the light emitting surface 221 may also be determined by factors such as the refractive index of air, the refractive index of the material of the total reflection lens 200 , and the inclination angle of the sidewall 214 .

[0118] Furthermore, when assembling the various optical components in the optical projection system 10, it is necessary to control the relative distance between the total reflection lens 200, the insulating glass 300, and the polarizer located thereon. For example, when the distance between the insulating glass 300 and the total reflection lens 200 is too close or too far, the light spot 900 on the insulating glass 300 becomes circular, and the primary light spot 910 and the secondary light spot 920 become separated. When the distance between the insulating glass 300 and the total reflection lens 200 is moderate, the light spot 900 on the insulating glass 300 becomes rectangular. The distance between the insulating glass 300 and the total reflection lens 200 can be adjusted based on actual conditions.

[0119] In this embodiment, the distance between the insulating glass 300 and the total reflection lens 200 is 6 mm. At this distance, the light spot formed on the insulating glass 200 by the luminous light source through the total reflection lens 200 is rectangular.

[0120] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0121] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0122] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0123] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0124] It should be understood that although the steps in the flowcharts of the accompanying drawings are shown in sequence as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in the flowcharts of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0125] The above description is only part of the implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A total reflection lens, characterized in that, The total reflection lens includes a collimating portion and a beam expanding portion; In the direction from the collimating portion to the beam expanding portion, the cross-sectional dimension of the collimating portion increases; At the connection position between the collimating portion and the beam expanding portion, the cross-sectional area of the total reflection lens changes abruptly, and the cross-sectional area of the collimating portion is larger than that of the beam expanding portion.

2. The total reflection lens according to claim 1, wherein At the connection position between the collimating portion and the beam expanding portion, the minimum distance from the edge of the collimating portion to the edge of the beam expanding portion is a first distance, the first distance is greater than or equal to 0.5 mm and less than or equal to 2 mm.

3. The total reflection lens according to claim 1, wherein, The peripheral wall of the collimating portion is in an arc protruding outward.

4. The total reflection lens according to claim 1, characterized in that, The collimating portion includes a first surface away from the beam expanding portion, and an inwardly concave light incident cavity is formed by extending inward from the first surface; In the direction from the collimating portion to the beam expanding portion, the cross-sectional area of the light incident cavity gradually decreases.

5. The total reflection lens according to claim 4, wherein The light incident cavity includes a side wall and a top wall, and the slopes corresponding to each position of the side wall are the same; and / or The top wall bulges away from the beam expanding portion and is in an arc shape.

6. The total reflection lens according to claim 4, characterized in that, The ratio of the depth of the light incident cavity to the height of the collimating portion is greater than or equal to 1 / 5 and less than or equal to 1 / 2.

7. The total reflection lens according to claim 1, characterized in that, The beam expanding portion includes a light emitting surface away from the collimating portion; In a first plane, the edge region of the light emitting surface bulges compared with the central region; in a second plane, the edge region of the light emitting surface bulges compared with the central region; there is an included angle between the first plane and the second plane; Both the first plane and the second plane are parallel to the connecting direction of the collimating portion and the beam expanding portion.

8. The total reflection lens according to claim 7, wherein The first plane and the second plane are perpendicular, and the number of the bulges is four.

9. An optical projection system, characterized in that, The optical projection system includes the total reflection lens according to any one of claims 1-8, and the number of the total reflection lenses is multiple.

10. The optical projection system according to claim 9, wherein, The optical projection system further includes a heat insulating glass, and the heat insulating glass is disposed near the beam expanding portion of the total reflection lens; Each total reflection lens includes an inwardly concave light incident cavity formed by extending inward from the collimating portion away from the beam expanding portion; the light incident cavity includes a side wall and a top wall; the light spot formed on the heat insulating glass by the light passing through the side wall of the light incident cavity and the peripheral wall of the collimating portion in sequence is used as a secondary light spot; the light spot formed on the heat insulating glass by the light passing through the top wall of the light incident cavity is used as a main light spot; At least part of the structure of the secondary light spots formed by adjacent total reflection lenses overlaps.

11. The optical projection system according to claim 9, wherein The distance between adjacent total reflection lenses is greater than or equal to 0.05 mm and less than or equal to 5 mm.

12. A projection optical machine, characterized in that, The projection optical machine includes a housing and the optical projection system according to any one of claims 9-11, and the optical projection system is located inside the housing.

Images