Projection light machine and projection device

Abstract

The application relates to a projection light machine and a projection device. The projection light machine comprises a light source, a light cone, a collimating lens, a focusing lens and a lens which are arranged in sequence along the propagation path of the outgoing light of the light source; the light cone is used for collecting the outgoing light of the light source and emitting the light rays from an outlet; the collimating lens is used for collimating the light rays; the focusing lens is used for converging the light rays towards the lens; and the lens is used for projecting the light rays; the projection light machine satisfies the condition formula: [|ra2|, |rb2|]max <= D / 2; ra2 is the distance between the incident point of the light ray directly emitted at the edge of the outlet on the lens and the optical axis; rb2 is the distance between the incident point of the light ray emitted from the light cone after reflection at the edge of the outlet on the lens and the optical axis; and D is the effective aperture of the lens. The above projection light machine has small light ray loss, high light ray utilization rate and is beneficial to improving the projection brightness.

Description

Technical Field

[0001] This application relates to the field of projection equipment technology, and in particular to a projection optical engine and projection equipment. Background Technology

[0002] LCD projectors typically consist of a lighting system, an LCD display system, and an imaging system. LCD projectors, based on Kohler lighting, project the image displayed on the LCD onto a screen through a lens. Compared to projectors using other principles, such as DLP projectors and LCoS projectors, LCD projectors are inexpensive and simple to manufacture. However, traditional LCD projectors suffer from significant light loss, which can easily lead to decreased projection brightness and negatively impact the viewing experience. Summary of the Invention

[0003] Therefore, it is necessary to provide a projection optical engine and projection device to address the serious light loss problem of traditional LCD projectors.

[0004] A projection optical engine, comprising a light source and a light cone, a collimating lens, a focusing lens, and a lens arranged sequentially along the propagation path of the emitted light from the light source;

[0005] The light cone has a light inlet and a light outlet at its two ends, respectively. The light cone is used to receive the light emitted from the light source through the light inlet and emit the light from the light outlet. The collimating lens is used to collimate the light. The focusing lens is used to converge the light towards the lens. The lens is used to project the light.

[0006] The projection optical engine satisfies the condition: [|ra2|,|rb2|]max≤D / 2;

[0007] Where ra2 is the distance between the incident point of the light rays directly emitted from the edge of the light outlet and the optical axis on the lens, rb2 is the distance between the incident point of the light rays reflected from the edge of the light outlet and emitted from the light cone on the lens and the optical axis, and D is the effective aperture of the lens.

[0008] The aforementioned projection optical engine effectively compresses the aperture of the emitted beam from the light source through the light-collecting effect of the light cone, the collimating effect of the collimating lens, and the focusing effect of the focusing lens. This effectively reduces the height of the light beam entering the lens. Combined with a design where ra2 and rb2 are less than or equal to D / 2, the height of the light beam entering the lens remains within the effective aperture range of the lens. This helps reduce light loss, improves light utilization, and thus enhances projection brightness. Simultaneously, the reduced height of the light beam entering the lens also allows for a smaller effective aperture, thereby reducing the lens's footprint and manufacturing costs, and ultimately contributing to a smaller overall size of the projection optical engine.

[0009] In one embodiment, the light cone has a first reflective surface and a second reflective surface arranged opposite to each other, and the distance between the first reflective surface and the second reflective surface gradually increases in the direction along the optical axis from the light inlet to the light outlet.

[0010] In one embodiment, the projection optical engine satisfies the following condition:

[0011]

[0012] Where r is the distance between the edge of the light outlet of the light cone and the optical axis, d1 is the distance between the collimating lens and the focusing lens on the optical axis, d2 is the distance between the focusing lens and the lens on the optical axis, α is the angle between the first reflective surface and the second reflective surface, θ is the angle between the light ray directly emitted from the edge of the light outlet and the optical axis, f1 is the focal length of the collimating lens, and f2 is the focal length of the focusing lens.

[0013] In one embodiment, the projection optical engine satisfies the following condition:

[0014]

[0015] Where r is the distance between the edge of the light outlet of the light cone and the optical axis, d1 is the distance between the collimating lens and the focusing lens on the optical axis, d2 is the distance between the focusing lens and the lens on the optical axis, α is the angle between the first reflective surface and the second reflective surface, θ is the angle between the light ray directly emitted from the edge of the light outlet and the optical axis, f1 is the focal length of the collimating lens, and f2 is the focal length of the focusing lens.

[0016] In one embodiment, the light-emitting surface of the light source is approximately rectangular in shape, the light inlet and light outlet of the light cone are approximately rectangular in shape, the cross-sectional area of ​​the light cone is approximately rectangular, and the cross-sectional area of ​​the light cone gradually increases along the optical axis from the light inlet to the light outlet.

[0017] In one embodiment,

[0018] The length of the emitting surface of the light source is greater than or equal to 12.5 mm and less than or equal to 14 mm, and the width is greater than or equal to 6 mm and less than or equal to 7.2 mm; and / or,

[0019] The length of the light inlet is greater than or equal to 12.7 mm and less than or equal to 14.5 mm, and the width is greater than or equal to 6.2 mm and less than or equal to 7.7 mm; the length of the light outlet is greater than or equal to 92 mm and less than or equal to 100 mm, and the width is greater than or equal to 54 mm and less than or equal to 60 mm; the distance between the light inlet and the light outlet on the optical axis is greater than or equal to 55 mm and less than or equal to 60 mm.

[0020] In one embodiment,

[0021] The focal length of the collimating lens is greater than or equal to 70 mm and less than or equal to 85 mm; and / or,

[0022] The focal length of the focusing lens is greater than or equal to 110 mm and less than or equal to 125 mm; and / or,

[0023] The distance on the optical axis between the light outlet and the collimating lens is less than or equal to 0.6 mm; and / or,

[0024] The distance between the collimating lens and the focusing lens on the optical axis is greater than or equal to 18 mm and less than or equal to 20 mm.

[0025] In one embodiment, the projection optical engine further includes a polarizer disposed between the collimating lens and the focusing lens, the polarizer being used to convert light into polarized light.

[0026] In one embodiment, the light source includes a light-emitting diode made by a eutectic process.

[0027] In one embodiment, the power density of the light source is greater than or equal to 0.82 W / mm². 2 And less than or equal to 1.1 W / mm 2 .

[0028] A projection device comprising a projection optical engine as described in any of the above embodiments. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the projection optical engine in some embodiments.

[0030] Figure 2 This is a schematic diagram of the structure of the light cone in some embodiments.

[0031] Figure 3 This is a schematic diagram showing the angles of the first and second light rays exiting the light cones in some embodiments.

[0032] Figure 4This is a schematic diagram of the light path in some embodiments, showing the light emanating from the edge of the light outlet after a single reflection from the light cone.

[0033] Figure 5 This is a schematic diagram of the light path in some embodiments, showing how light is reflected twice by the light cone and then exits just at the edge of the light outlet.

[0034] Figure label:

[0035] 10. Projection optical engine; 11. Light source; 12. Light cone; 121. Light inlet; 122. Light outlet; 123. First reflective surface; 124. Second reflective surface; 125. Third reflective surface; 126. Fourth reflective surface; 13. Collimating lens; 14. Light modulation element; 15. Focusing lens; 16. Lens; 17. Optical axis; 18. First ray; 19. Second ray; 21. Polarizer. Detailed Implementation

[0036] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0037] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional 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, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0038] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0039] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0040] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0041] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0042] See Figure 1 , Figure 1 A schematic diagram of the structure of a projection optical engine 10 in one embodiment of this application is shown. The projection optical engine 10 provided in this application can be used in projection devices such as projectors. The projection device can be configured to use a projection screen. The projection optical engine 10 is configured to project light onto the projection screen to form an image.

[0043] In some embodiments, the projection optical engine 10 includes a light source 11 and, sequentially arranged along the propagation path of the emitted light from the light source 11, a light cone 12, a collimating lens 13, a light modulation element 14, a focusing lens 15, and a lens 16. The light source 11 is used to emit light, and the light source 11 includes, but is not limited to, light-emitting elements such as light-emitting diodes (LEDs). The light cone 12 is used to collect the emitted light from the light source 11 and direct the light towards the collimating lens 13. The collimating lens 13 is used to collimate the light emitted from the light cone 12, for example, by converging diverging beams to make the beams approximately parallel. The light modulation element 14 is used to modulate the collimated light so that the light projected by the projection optical engine 10 onto the projection screen can form a specific image or picture, or improve the imaging quality of the light projected onto the projection screen. The type of the light modulation element 14 is not limited and can be designed according to the light modulation requirements of the projection optical engine 10. The type of the light modulation element 14 includes, but is not limited to, a liquid crystal display (LCD). The focusing lens 15 is used to converge the light modulated by the light modulation element 14 and emit it toward the lens 16. The lens 16 can adjust the light and project it onto the projection screen to improve the image quality of the light on the projection screen.

[0044] Combination Figure 1 and Figure 2 As shown, in some embodiments, the two ends of the light cone 12 are respectively provided with a light inlet 121 and a light outlet 122. The light source 11 can be correspondingly disposed at the light inlet 121, and the light outlet 122 is disposed facing the collimating lens 13. In some embodiments, the shape of the light-emitting surface of the light source 11 is approximately rectangular, the light inlet 121 and the light outlet 122 of the light cone 12 can be approximately rectangular, and the cross-section of the light cone 12 can also be approximately rectangular to adapt to the shape of the light source 11 and the projection screen, thereby obtaining a good imaging effect. In some embodiments, along the optical axis 17 of the projection optical engine 10 from the light inlet 121 to the light outlet 122, the cross-sectional area of ​​the light cone 12 gradually increases to effectively collect the light from the light source 11 and emit the light toward the collimating lens 13. In some embodiments, the inner wall of the light cone 12 has a first reflective surface 123 and a second reflective surface 124 disposed opposite to each other, and the first reflective surface 123 and the second reflective surface 124 can respectively correspond to the two long sides of the cross-section of the light cone 12. Along the optical axis 17, from the light inlet 121 to the light outlet 122, the distance between the first reflective surface 123 and the second reflective surface 124 gradually increases. Part of the light emitted from the light source 11 can undergo one or more reflections on the first reflective surface 123 and / or the second reflective surface 124 before exiting through the light outlet 122, allowing the light cone 12 to concentrate the light emitted from the light source 11. Of course, the remaining light emitted from the light source 11 can directly strike the collimating lens 13 without reflection from the first reflective surface 123 and the second reflective surface 124.

[0045] Combination Figure 1 and Figure 3 As shown, it can be understood that the light emitted from the light source 11 exits from the light exit port 122, passes through the collimating lens 13, the light modulation element 14, and the focusing lens 15, and forms a beam projected onto the lens 16. A portion of the light emitted from the edge of the light exit port 122 corresponds to the outermost beam of the beam projected onto the lens 16, and the light emitted from the edge of the light exit port 122 determines the height of the beam projected onto the lens 16. The light ray emitting the light cone 12 from the edge of the light exit port 122 includes at least two parts: one part is emitted directly from the light exit port 122 without reflection at the edge of the light exit port 122, and the other part is reflected at the edge of the light exit port 122 to emit the light cone 12, for example, by reflection from the edge of the first reflective surface 123 or the second reflective surface 124 away from the light source 11. For ease of description, in this application, the light ray directly emitted from the edge of the light outlet 122 is referred to as the first light ray 18, and the light ray reflected from the edge of the light outlet 122 is referred to as the second light ray 19. Figure 1 In the illustrated embodiment, the paths of the first ray 18 and the second ray 19 are indicated by different types of dashed lines. Of course, the first ray 18 may also be reflected once or multiple times inside the light cone 12 before reaching the light outlet 122, and then emitted directly from the edge of the light outlet 122.

[0046] In some embodiments, the projection optical engine 10 satisfies the condition: [|ra2|,|rb2|]max≤D / 2; where ra2 is the distance between the incident point of the light ray directly emitted from the edge of the light outlet 122 on the lens 16 and the optical axis 17, that is, the distance between the incident point of the first light ray 18 on the lens 16 and the optical axis 17; rb2 is the distance between the incident point of the light ray reflected from the edge of the light outlet 122 and emitted from the light cone 12 on the lens 16 and the optical axis 17, that is, the distance between the incident point of the second light ray 19 on the lens 16 and the optical axis 17; and D is the effective aperture of the lens 16. The height of the light beam projected onto lens 16 is determined by the light rays emitted from light outlet 122, specifically by the first ray 18 and the second ray 19. Therefore, designing the incident height of the first ray 18 and the second ray 19 on lens 16 to be less than or equal to half the effective aperture of lens 16 effectively limits the light beam projected onto lens 16 to within the effective aperture range of lens 16. This ensures the light beam can fully enter lens 16 and be projected onto the projection screen, effectively reducing light damage and improving light utilization. It is understood that light rays emitting from other positions of light outlet 122, and light rays emitting from the edge of light outlet 122 at angles different from the first ray 18 and the second ray 19, have incident heights on lens 16 that are lower than those of the first ray 18 and the second ray 19. Therefore, designing the incident height of the first ray 18 and the second ray 19 on lens 16 ensures that the light beam projected onto lens 16 is within the effective aperture range of lens 16.

[0047] The aforementioned projection optical engine 10, with its light-collecting function of the light cone 12, collimating function of the collimating lens 13, and focusing function of the focusing lens 15, effectively compresses the aperture of the emitted beam from the light source 11. This effectively reduces the light height of the incident lens 16. Combined with the design that ra2 and rb2 are less than or equal to D / 2, this ensures that the light height of the incident lens 16 remains within the effective aperture range of the lens 16. This helps reduce light loss, improves light utilization, and thus enhances projection brightness. Simultaneously, the reduced light height of the incident lens 16 also helps to shrink the effective aperture of the lens 16, thereby reducing the space occupied by the lens 16 and manufacturing costs, and ultimately reducing the overall size of the projection optical engine 10.

[0048] Furthermore, combined Figure 1 and Figure 3 In some embodiments, when the first ray 18 exits the light cone 12 from the edge of the light outlet 122, the angle between the first ray 18 and the optical axis 17 is 0.5α+θ; the distance between the first ray 18's incident point on the collimating lens 13 and the optical axis 17 is called ra, and ra satisfies:

[0049] ra=r+d*tan(0.5α+θ)

[0050] Where r is the distance between the edge of the light exit 122 of the light cone 12 and the optical axis 17, that is, the distance between the exit point of the first ray 18 at the light exit 122 and the optical axis 17; d is the distance between the light exit 122 and the collimating lens 13 in the direction of the optical axis 17; and α is the angle between the first reflecting surface 123 and the second reflecting surface 124. Figure 1 The angle between the cross section of the light cone 12 shown and the extension lines of the corresponding sides of the first reflective surface 123 and the second reflective surface 124 is θ, which is the angle between the first ray 18 and the first reflective surface 123 or the second reflective surface 124 when the first ray 18 exits the light outlet 122. When the first ray 18 exits from the first reflective surface 123, θ is the angle between the first ray 18 and the first reflective surface 123. When the first ray 18 exits from the second reflective surface 124, θ is the angle between the first ray 18 and the second reflective surface 124.

[0051] When the first ray 18 exits from the collimating lens 13 and strikes the focusing lens 15, the first ray 18 satisfies the following condition:

[0052]

[0053] ra1=r+d1*tanθa1

[0054] Wherein, θa1 is the angle between the first ray 18 and the optical axis 17 when it exits the collimating lens 13, that is, the angle between the first ray 18 and the optical axis 17 when it enters the focusing lens 15, f1 is the focal length of the collimating lens 13, ra1 is the distance between the point of incidence of the first ray 18 on the focusing lens 15 and the optical axis 17, and d1 is the distance between the collimating lens 13 and the focusing lens 15 on the optical axis 17.

[0055] When the first ray 18 exits from the focusing lens 15 and strikes the incident surface of the lens 16, the first ray 18 satisfies the following condition:

[0056]

[0057] ra2=ra1+d2*tanθa2

[0058] Wherein, θa2 is the angle between the first ray 18 and the optical axis 17 when it exits the focusing lens 15, that is, the angle between the first ray 18 and the optical axis 17 when it enters the light-incident surface of the lens 16; f2 is the focal length of the focusing lens 15; ra2 is the distance between the incident point of the first ray 18 on the lens 16 and the optical axis 17; and d2 is the distance between the focusing lens 15 and the light-incident surface of the lens 16 on the optical axis 17.

[0059] From the above relationship, we can deduce that:

[0060]

[0061] In some embodiments, the projection optical engine 10 satisfies the following condition:

[0062]

[0063] When the above conditions are met, by designing the relationship between r, d1, d2, α, θ, f1, and f2 and the effective aperture of lens 16, the incident point of the first ray 18 on lens 16 can be located within the effective aperture range of lens 16. This allows the first ray 18 to be effectively received by lens 16, reducing light loss and improving light utilization. It can be understood that the first ray 18 emitted from the first reflective surface 123 and the second reflective surface 124, when incident on lens 16, is located on both sides of the optical axis 17, where is defined as being located on... Figure 1 The ra2 of the first ray 18 above the optical axis 17 is positive, defined as located at... Figure 1 The ra2 value of the first ray 18 below the central optical axis 17 is negative.

[0064] For the second ray 19, when the second ray 19 exits the light cone 12 from the edge of the light outlet 122, the angle between the second ray 19 and the optical axis 17 is 0.5α-θ; the first ray 18 strikes the collimating lens 13 from the light cone 12, and the distance between the incident point on the collimating lens 13 and the optical axis 17 is called rb, which satisfies:

[0065] rb=r+d*tan(0.5α-θ)

[0066] Where r is the distance between the edge of the light exit 122 of the light cone 12 and the optical axis 17, that is, the distance between the exit point of the second ray 19 at the light exit 122 and the optical axis 17; d is the distance between the light exit 122 and the collimating lens 13 in the direction of the optical axis 17; and α is the angle between the first reflecting surface 123 and the second reflecting surface 124. Figure 1 The angle between the cross section of the light cone 12 shown and the extension lines of the corresponding sides of the first reflective surface 123 and the second reflective surface 124 is θ, which is the angle between the second ray 19 and the first reflective surface 123 or the second reflective surface 124 when the second ray 19 exits the light outlet 122. When the second ray 19 exits from the first reflective surface 123, θ is the angle between the second ray 19 and the first reflective surface 123. When the second ray 19 exits from the second reflective surface 124, θ is the angle between the second ray 19 and the second reflective surface 124.

[0067] When the second ray 19 exits from the collimating lens 13 and strikes the focusing lens 15, the second ray 19 satisfies the following condition:

[0068]

[0069] rb1 = r + d1 * tanθb1

[0070] Wherein, θb1 is the angle between the second ray 19 and the optical axis 17 when it exits the collimating lens 13, that is, the angle between the second ray 19 and the optical axis 17 when it enters the focusing lens 15, f1 is the focal length of the collimating lens 13, rb1 is the distance between the incident point of the second ray 19 on the focusing lens 15 and the optical axis 17, and d1 is the distance between the collimating lens 13 and the focusing lens 15 on the optical axis 17.

[0071] When the second ray 19 exits from the focusing lens 15 and strikes the incident surface of the lens 16, the second ray 19 satisfies the following condition:

[0072]

[0073] rb2 = rb1 + d2 * tanθb2

[0074] Wherein, θb2 is the angle between the second ray 19 and the optical axis 17 when it exits the focusing lens 15, that is, the angle between the second ray 19 and the optical axis 17 when it enters the light-incident surface of the lens 16; f2 is the focal length of the focusing lens 15; rb2 is the distance between the incident point of the second ray 19 on the lens 16 and the optical axis 17; and d2 is the distance between the focusing lens 15 and the light-incident surface of the lens 16 on the optical axis 17.

[0075] From the above relationship, we can deduce that:

[0076]

[0077] In some embodiments, the projection optical engine 10 satisfies the following condition:

[0078]

[0079] When the above conditions are met, by designing the relationship between r, d1, d2, α, θ, f1, and f2 and the effective aperture of lens 16, the incident point of the second ray 19 on lens 16 can be located within the effective aperture range of lens 16. This allows the second ray 19 to be effectively received by lens 16, reducing light loss and improving light utilization. It can be understood that the second ray 19 emitted from the first reflective surface 123 and the second reflective surface 124, when incident on lens 16, is located on both sides of the optical axis 17, where is defined as being located on... Figure 1 The second ray 19 above the central optical axis 17 has a positive rb2 value, defined as located at... Figure 1 The rb2 value of the second ray 19 below the central optical axis 17 is negative.

[0080] It should be noted that when both the light inlet 121 and the light outlet 122 are rectangular, Figure 1 This can be a cross-sectional view of the plane containing the line connecting the midpoints of the two long sides of the light inlet 121 and the line connecting the midpoints of the two long sides of the light outlet 122 of the projection optical engine 10. Combined with... Figure 1 and Figure 2 As shown, the light cone 12 may also include opposing third reflective surfaces 125 and fourth reflective surfaces 126, which may correspond to the short side of the rectangle of the cross-section of the light cone 12. It is understood that when light exits from the short edge of the light outlet 122, i.e., from the edge of the third reflective surfaces 125 and fourth reflective surfaces 126 away from the light source 11, the incident height of the light on the lens 16 can be made within the effective aperture range of the lens 16 by designing r, d1, d2, α, θ, f1, and f2. Here, θ is the angle between the light and the third reflective surface 125 or fourth reflective surface 126 when the light exits from the edge of the third reflective surface 125 and fourth reflective surface 126 away from the light source 11. The specific design and derivation process are based on the above description and will not be repeated here.

[0081] It is understandable that the light emitted by the light source 11 undergoes different numbers of reflections within the light cone 12 before exiting through the light exit port 122. The angle θ between the light ray exiting the light exit port 122 and the first reflective surface 123 or the second reflective surface 124 also differs. The following example uses the θ value after the light ray undergoes one or two reflections within the light cone 12. Of course, the number of reflections within the light cone 12 is not limited to one or two; it can also be three, four, or more times. Combined with... Figure 1 and Figure 4 As shown, after the light undergoes one reflection within the light cone 12, it exits from the light exit port 122, for example, at the light inlet port 121. Figure 4 When reflection occurs at point A, the reflection path at point A can be determined by the sine theorem:

[0082]

[0083] Where x is the length of the line of the cross section of the light cone 12 corresponding to the light inlet 121, for example, it can be the width of the light inlet 121; α is the angle between the first reflective surface 123 and the second reflective surface 124; and y1 is the length of the line of the cross section of the light cone 12 corresponding to the first reflective surface 123 or the second reflective surface 124 when the light is reflected once by the light cone 12 and just exits at the edge of the light outlet 122.

[0084] It can be known that:

[0085]

[0086] It can be known that:

[0087]

[0088] Therefore, it can be seen that when the length y of the line corresponding to the first reflective surface 123 or the second reflective surface 124 of the cross section of the light cone 12 satisfies:

[0089]

[0090] At that time, the light beam is reflected once within the light cone 12 and then exits from the light outlet 122. Please refer to [other sources]. Figure 4 The reflection path at point A can be determined using the sine theorem:

[0091]

[0092] It can be known that:

[0093]

[0094] Therefore, when light cone 12 satisfies:

[0095]

[0096] At that time, the light emitted by the light source 11 undergoes one reflection within the light cone 12 before exiting. The value of θ can be obtained by solving the following conditional equation:

[0097]

[0098] Combination Figure 1 and Figure 5 As shown, after the light undergoes two reflections within the light cone 12, it exits from the light exit port 122, for example, at the light inlet port 121. Figure 5 Point A as shown, and on the first reflective surface 123 or the second reflective surface 124, i.e. Figure 5 When reflection occurs at point B, the reflection path at point A can be determined using the sine theorem:

[0099]

[0100] Where z1 is the path length of the light ray when it travels from point A to point B.

[0101] It can be known that:

[0102]

[0103] The reflection path at point B can be determined using the law of sines:

[0104]

[0105] Where y2 is the length of the line on the cross section of the light cone 12 corresponding to the first reflective surface 123 or the second reflective surface 124 when the light is emitted from the edge of the light outlet 122 after being reflected twice by the light cone 12.

[0106] It can be known that:

[0107]

[0108] It can be known that:

[0109]

[0110] It can be known that:

[0111]

[0112] Therefore, it can be seen that when the length y of the line corresponding to the first reflective surface 123 or the second reflective surface 124 of the cross section of the light cone 12 satisfies:

[0113]

[0114] At that time, the light beam is reflected once within the light cone 12 and then exits from the light outlet 122. Please refer to [other sources]. Figure 5 Therefore, we can conclude that:

[0115]

[0116] Where θ1 is the angle between the light ray after reflection at point A and the plane where the light inlet 121 is located.

[0117] The reflection path at point A can be determined using the law of sines:

[0118]

[0119] Where z1 is the length of the path traversed by the ray of light from point A to point B.

[0120] It can be known that:

[0121]

[0122] The reflection path at point B can be determined using the law of sines:

[0123]

[0124] Where y2 is the length of the line on the cross-section of the light cone 12 corresponding to the first reflective surface 123 or the second reflective surface 124 when the light is emitted twice within the light cone 12 and exits precisely at the edge of the light exit port 122. It can be seen that:

[0125]

[0126] It can be known that:

[0127]

[0128] Therefore, when light cone 12 satisfies:

[0129]

[0130] At that time, the light emitted by the light source 11 is reflected twice within the light cone 12 and then exits from the light outlet 122. The value of θ can be obtained by solving the following conditional equation:

[0131]

[0132] In some embodiments, the length of the emitting surface of the light source 11 is greater than or equal to 12.5 mm and less than or equal to 14 mm, and the width is greater than or equal to 6 mm and less than or equal to 7.2 mm. The length of the light inlet 121 is greater than or equal to 12.7 mm and less than or equal to 14.5 mm, and the width is greater than or equal to 6.2 mm and less than or equal to 7.7 mm. The length of the light outlet 122 is greater than or equal to 92 mm and less than or equal to 100 mm, and the width is greater than or equal to 54 mm and less than or equal to 60 mm. The distance between the light inlet 121 and the light outlet 122 on the optical axis 17 is greater than or equal to 55 mm and less than or equal to 60 mm. The focal length of the collimating lens 13 is greater than or equal to 70 mm and less than or equal to 85 mm. The focal length of the focusing lens 15 is greater than or equal to 110 mm and less than or equal to 125 mm. The distance between the light outlet 122 and the collimating lens 13 on the optical axis 17 is less than or equal to 0.6 mm. The distance between the collimating lens 13 and the focusing lens 15 on the optical axis 17 is greater than or equal to 18 mm and less than or equal to 20 mm. Meeting these numerical ranges allows for a reasonable design of the projection optical engine 10's structure, ensuring that its structural features satisfy the aforementioned embodiments. This ensures that the incident height of the light emitted from the light source 11 on the lens 16 after passing through the light cone 12, collimating lens 13, light modulation element 14, and focusing lens 15 is within the effective aperture range of the lens 16, effectively improving light utilization.

[0133] It is understood that the collimating lens 13 and the focusing lens 15 may include a single lens with optical power, or multiple lenses with optical power, as long as they can achieve the corresponding collimation or focusing functions. The arrangement of the lens 16 is also not limited; the lens 16 may include one or more lenses with optical power to adjust the light and improve the imaging quality of the projection engine 10. The specific arrangement of the lens 16 can be designed according to the light adjustment and imaging requirements, and is not limited in this application. In some embodiments, the lenses, collimating lens 13, and focusing lens 15 within the lens 16 are coaxially arranged, and the common axis of all lenses can be understood as the optical axis 17 of the projection engine 10. In some embodiments, the light source 11 can be fixedly connected to the light cone 12 by any suitable connection method such as adhesive, so that the emitted light from the light source 11 can be collected by the light cone 12 to the maximum extent.

[0134] In some embodiments, the projection optical engine 10 may include heat-insulating glass, which may be disposed between the collimating lens 13 and the light modulation element 14. The heat-insulating glass can isolate the heat of the light source 11 and the light cone 12, preventing excessive temperature from damaging the light modulation element 14 or other components. In some embodiments, the projection optical engine 10 may also include a polarizer 21, which is disposed between the collimating lens 13 and the light modulation element 14. The polarizer 21 is used to convert light into polarized light, for example, converting the emitted light from the light source 11 into linearly polarized light to adapt to the LCD settings. In some embodiments, the polarizer 21 may be integrated with the heat-insulating glass, for example, using glass with heat-insulating properties to make the polarizer 21, which helps to reduce the size of the projection optical engine 10 and improve the user experience.

[0135] In some embodiments, the light source 11 includes LEDs fabricated using a eutectic process, and the power density of the LEDs input to the light source 11 can be greater than or equal to 0.82 W / mm². 2 And less than or equal to 1.1 W / mm 2Using eutectic LEDs as the light source 11 improves the power density of the input light source 11, allowing the light source 11 of the same area to emit more intense light. This satisfies lighting requirements while reducing the size of the light-emitting surface of the light source 11, which in turn reduces the aperture of the lens 16, compresses the space occupied by the projection optical engine 10, and lowers manufacturing costs. Simultaneously, the reduced light-emitting surface area of ​​the light source 11 also helps to lower the incident angle of the emitted light on the collimating lens 13 and polarizer 21. A lower incident angle on the polarizer 21 improves its polarization efficiency and reduces light loss, further enhancing light utilization and projection brightness. Furthermore, the increased power density of the light source 11 also reduces the heat generated during emission, lowering the temperature of the light source 11 and the light cone 12, thus improving the heat dissipation performance of the projection optical engine 10.

[0136] In some embodiments, this application also provides a projection device, which includes a housing and a projection optical engine 10 as described in any of the above embodiments. The projection optical engine 10 is disposed within the housing, which can be a mechanical structure for mounting the various components within the projection optical engine 10. The projection device includes, but is not limited to, a projector, and is capable of projecting the emitted light from the projection optical engine 10 onto a projection screen to form an image. Using the aforementioned projection optical engine 10 in the projection device results in low light loss and high light utilization, which is beneficial for improving the brightness of the projected image, thereby enhancing the viewing experience.

[0137] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0138] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A projection optical engine, characterized in that, The projection optical engine includes a light source and a light cone, a collimating lens, a focusing lens, and a lens arranged sequentially along the propagation path of the emitted light from the light source. The light cone has a light inlet and a light outlet at its two ends, respectively. The light cone is used to receive the light emitted from the light source through the light inlet and emit the light from the light outlet. The collimating lens is used to collimate the light. The focusing lens is used to converge the light towards the lens. The lens is used to project the light. The light cone has a first reflective surface and a second reflective surface arranged opposite to each other, and the distance between the first reflective surface and the second reflective surface gradually increases in the direction along the optical axis from the light inlet to the light outlet; The projection optical engine satisfies the following condition: [|ra2|,|rb2|]max≤D / 2; ； Wherein, ra2 is the distance between the incident point of the light ray directly emitted from the edge of the light outlet on the lens and the optical axis; rb2 is the distance between the incident point of the light ray reflected from the edge of the light outlet and emitted from the light cone on the lens and the optical axis; D is the effective aperture of the lens; r is the distance between the edge of the light outlet of the light cone and the optical axis; d1 is the distance between the collimating lens and the focusing lens on the optical axis; d2 is the distance between the focusing lens and the lens on the optical axis; α is the angle between the first reflective surface and the second reflective surface; θ is the angle between the light ray directly emitted from the edge of the light outlet and the optical axis; f1 is the focal length of the collimating lens; and f2 is the focal length of the focusing lens.

2. The projection optical engine according to claim 1, characterized in that, The projection optical engine satisfies the following condition: 。 3. The projection optical engine according to claim 1, characterized in that, The light-emitting surface of the light source is roughly rectangular in shape, the light inlet and light outlet of the light cone are roughly rectangular in shape, the cross-sectional area of ​​the light cone is roughly rectangular, and the area of ​​the cross-section of the light cone gradually increases along the optical axis from the light inlet to the light outlet.

4. The projection optical engine according to claim 3, characterized in that, The length of the light-emitting surface of the light source is greater than or equal to 12.5 mm and less than or equal to 14 mm, and the width is greater than or equal to 6 mm and less than or equal to 7.2 mm.

5. The projection optical engine according to claim 3, characterized in that, The length of the light inlet is greater than or equal to 12.7 mm and less than or equal to 14.5 mm, and the width is greater than or equal to 6.2 mm and less than or equal to 7.7 mm; the length of the light outlet is greater than or equal to 92 mm and less than or equal to 100 mm, and the width is greater than or equal to 54 mm and less than or equal to 60 mm; the distance between the light inlet and the light outlet on the optical axis is greater than or equal to 55 mm and less than or equal to 60 mm.

6. The projection optical engine according to claim 1, characterized in that, The focal length of the collimating lens is greater than or equal to 70 mm and less than or equal to 85 mm; and / or, The focal length of the focusing lens is greater than or equal to 110 mm and less than or equal to 125 mm; and / or, The distance on the optical axis between the light outlet and the collimating lens is less than or equal to 0.6 mm; and / or, The distance between the collimating lens and the focusing lens on the optical axis is greater than or equal to 18 mm and less than or equal to 20 mm.

7. The projection optical engine according to claim 1, characterized in that, The projection optical engine also includes a polarizer, which is disposed between the collimating lens and the focusing lens, and is used to convert light into polarized light.

8. The projection optical engine according to claim 1, characterized in that, The light source includes light-emitting diodes manufactured using a eutectic process.

9. The projection optical engine according to claim 1, characterized in that, The power density of the light source is greater than or equal to 0.82 W / mm². 2 And less than or equal to 1.1 W / mm 2 .

10. A projection device, characterized in that, The projection device includes a projection optical engine as described in any one of claims 1-9.

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