Reflection cup and projection equipment

Abstract

The invention discloses a reflection cup and projection equipment, at least two reflection cup sections are arranged between a light inlet and a light outlet of the reflection cup, and each reflection cup section is formed by enclosing a plurality of reflection planes; and the inclination degrees of the two connected reflecting planes in different reflecting cup sections are different. The reflection cup section which is relatively closer to one side of the light outlet can reflect light rays which are possibly emitted from the light outlet at a large angle originally, so that the light rays are emitted at a smaller angle, and the effects of converging light beams and improving the collimation degree of the light beams are achieved. And therefore, light spots formed by projecting the light beams emitted by the reflection cup to the liquid crystal display panel can have better uniformity, and the image quality of a projection image can be improved.

Description

Technical Field

[0001] The present invention relates to the field of projection technology, and in particular to a reflective cup and projection equipment. Background Art

[0002] Liquid crystal display (LCD) technology is used to project light from a light source onto a liquid crystal display panel, producing an image. This image is then projected through a projection lens and formed into an image for viewing at a distance. Therefore, the uniformity of the light spot projected onto the LCD panel is a crucial factor in determining image quality.

[0003] LCD projection devices typically use light-emitting diodes (LEDs) as their light source due to their environmentally friendly and low-cost characteristics. LEDs are Lambertian light sources, resulting in a wide divergence angle for their emitted light beams. Their intensity is high at small angles and low at large angles. This results in low light utilization and uneven light spot quality on the LCD panel. Therefore, it is necessary to converge the emitted light beam from the LED source. Currently, two commonly used devices for converging the light beam are lenses and reflectors. Reflectors are relatively inexpensive and difficult to manufacture, making them more widely used.

[0004] Figure 1 It is a schematic diagram of the structure of a traditional reflective cup, such as Figure 1 As shown, the conventional reflector is a cup-shaped structure with a gradually increasing cross-sectional area. The light beam emitted by the light source 1 enters the interior of the reflector 2 through the light inlet In of the reflector 2, and part of the light (e.g. Figure 1 The light represented by the dotted line in the figure) is directly emitted from the light outlet Out of the reflective cup 2, while the other part of the light (for example Figure 1 The light (represented by the solid line in the figure) is reflected by the inner wall of the reflective cup 2, so that the divergence angle of the light beam emitted from the light outlet Out is smaller than that of the light beam emitted by the LED light source. That is, the light emitted by the LED light source is converged and collimated after being reflected by the reflective cup, which is beneficial to improving the uniformity of the light spot incident on the liquid crystal display panel.

[0005] As projectors become increasingly miniaturized, the height of the reflector cup needs to be reduced to minimize the overall size of the projection device. However, this reduction in reflector height prevents most light from being collimated by the reflector's inner wall, resulting in a reduced uniformity of the light spot projected onto the LCD panel. Furthermore, some high-angle edge light may be reflected by the projection device housing, resulting in stray light that affects the user's viewing experience. Therefore, traditional reflectors cannot achieve both the requirements of miniaturization and projection beam uniformity. Summary of the Invention

[0006] The present invention provides a reflective cup and a projection device, which are used to realize miniaturized design and increase the uniformity of the projection light beam.

[0007] In a first aspect, the present invention provides a reflector cup, comprising at least two reflector cup segments between a light inlet and a light outlet, wherein the reflector cup segments are surrounded by a plurality of reflective planes; and the inclination degrees of the two connected reflective planes in different reflector cup segments are different.

[0008] In some embodiments of the present invention, the reflective cup includes a first reflective cup segment and a second reflective cup segment, wherein the first reflective cup segment is located on a side close to the light entrance, and the second reflective cup segment is located on a side close to the light exit;

[0009] The first reflective cup segment is enclosed by multiple first reflective planes, and the second reflective cup segment is enclosed by multiple second reflective planes; each of the first reflective planes is connected to one of the second reflective planes, and the angle between the first reflective plane and the plane where the light entrance is located is greater than the angle between the second reflective plane and the plane where the light entrance is located.

[0010] In some embodiments of the present invention, the height of the first reflective cup segment in the optical axis direction of the reflective cup is a first height, the height of the second reflective cup segment in the optical axis direction of the reflective cup is a second height, and the first height is greater than the second height.

[0011] In some embodiments of the present invention, the first reflective cup segment is formed by two first reflective planes having a first area and two first reflective planes having a second area, the first area is smaller than the second area, and the first reflective planes having the same area are symmetrical about the optical axis of the reflective cup;

[0012] The second reflective cup segment is formed by two second reflective planes having a third area and two second reflective planes having a fourth area, the third area is smaller than the fourth area, and the second reflective planes having the same area are symmetrical about the optical axis of the reflective cup;

[0013] The first light-reflecting plane with the first area is connected to the second light-reflecting plane with the third area, and the first light-reflecting plane with the second area is connected to the second light-reflecting plane with the fourth area.

[0014] In some embodiments of the present invention, the first light-reflecting plane having the first area and the second light-reflecting plane having the third area satisfy the following relationship:

[0015] 1.1≤|K1|≤1.6;

[0016] 1.78≤|K2|≤2.08;

[0017] K1 represents the slope of the first light reflecting plane having the first area relative to the plane where the light entrance is located, and K2 represents the slope of the second light reflecting plane having the third area relative to the plane where the light entrance is located.

[0018] In some embodiments of the present invention, the first light-reflecting plane having the second area and the second light-reflecting plane having the fourth area satisfy the following relationship:

[0019] 0.3≤|K3|≤0.4;

[0020] 0.6≤|K4|≤0.7;

[0021] K3 represents the slope of the first light reflecting plane with the second area relative to the plane where the light entrance is located, and K4 represents the slope of the second light reflecting plane with the fourth area relative to the plane where the light entrance is located.

[0022] In some embodiments of the present invention, a ratio of the first height to the second height is greater than or equal to 12.

[0023] In some embodiments of the present invention, the height of the reflective cup in the optical axis direction is greater than or equal to 60 mm, and the height of the reflective cup in the optical axis direction is less than or equal to 65 mm.

[0024] In a second aspect, the present invention provides a projection device, comprising a light source, a liquid crystal display panel, and the reflective cup described in any one of the embodiments of the first aspect; the reflective cup is located between the light source and the liquid crystal display panel, the light source is located on a side close to the light entrance of the reflective cup, and the liquid crystal display panel is located on a side close to the light exit of the reflective cup.

[0025] In some embodiments of the present invention, the orthographic projection of the light outlet of the reflective cup on the liquid crystal display panel covers the display area of ​​the display panel.

[0026] In some embodiments of the present invention, the shape of the light outlet of the reflective cup is the same as the shape of the display area of ​​the liquid crystal display panel.

[0027] In some embodiments of the present invention, the light source includes a light emitting device and a lens, wherein the lens covers the light emitting device and is used to converge the light beam emitted by the light emitting device and emit it into the reflective cup.

[0028] In some embodiments of the present invention, the projection device further includes a pentaangular prism and a projection lens, wherein the pentaangular prism is located on the optical path between the liquid crystal display panel and the projection lens, and the light emitted from the liquid crystal display panel is reflected multiple times inside the pentaangular prism and then emitted toward the projection lens.

[0029] In some embodiments of the present invention, the pentaangular prism includes a light incident surface and a light exit surface, two light reflecting surfaces, and a connecting surface, wherein the light incident surface and the light exit surface are connected and perpendicular to each other, the two light reflecting surfaces are respectively connected to the light incident surface and the light exit surface, and the two light reflecting surfaces are arranged at a set angle, and the connecting surface connects the two light reflecting surfaces;

[0030] The light emitted from the liquid crystal display panel is incident on the inside of the pentagonal prism from the light incident surface, and is reflected by the two light reflecting surfaces inside the pentagonal prism and then emitted from the light emitting surface to the projection lens.

[0031] The beneficial effects of the present invention are as follows:

[0032] The present invention provides a reflector and projection device, wherein the reflector includes at least two reflector segments between a light inlet and a light outlet, each segment being formed by a plurality of reflective planes. The two adjacent reflective planes in different reflector segments have different inclinations. The reflector segment closer to the light outlet can reflect light that would otherwise exit from the light outlet at a large angle, causing it to exit at a smaller angle. This achieves the effects of converging the light beam and improving its collimation. Consequently, the light spot projected by the reflector onto the liquid crystal display panel has greater uniformity, which helps improve the quality of the projected image. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings introduced below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 It is a schematic diagram of the structure of a traditional reflector;

[0035] Figure 2 A schematic structural diagram of a reflective cup provided by an embodiment of the present invention;

[0036] Figure 3 A schematic cross-sectional view of a reflective cup provided by an embodiment of the present invention;

[0037] Figure 4 A schematic cross-sectional view of another reflective cup provided by an embodiment of the present invention;

[0038] Figure 5 A schematic structural diagram of a projection device provided by an embodiment of the present invention;

[0039] Figure 6A schematic diagram of the light path in another reflective cup provided by an embodiment of the present invention;

[0040] Figure 7 A schematic structural diagram of another projection device provided by an embodiment of the present invention;

[0041] Figure 8 A schematic structural diagram of a pentaprism provided in an embodiment of the present invention;

[0042] Description of reference numerals:

[0043] In-light inlet, Out-light outlet, L-optical axis, 101-first reflective cup segment, 102-second reflective cup segment, S1 / S11 / S12 / S13 / S14-first reflective plane, S2 / S21 / S22 / S23 / S24-second reflective plane, h1-first height, h2-second height, 1-light source, 11-light-emitting device, 12-lens, 2-reflective cup, 3-liquid crystal display panel, 4-collimating lens, 5-reflective device, 51-plane reflector, 52-penta prism, 6-focusing lens, 7-projection lens, S31-light incident surface, S32-light exit surface, S33 / S34-reflective surface, S35-connecting surface. DETAILED DESCRIPTION

[0044] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention will be further described below with reference to the accompanying drawings and examples. However, the example embodiments can be implemented in various forms and should not be understood as being limited to the embodiments described herein; on the contrary, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concepts of the example embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and their repeated descriptions will be omitted. The words expressing position and direction described in the present invention are all explained with reference to the accompanying drawings as examples, but changes can be made as needed, and the changes made are all included in the scope of protection of the present invention. The drawings of the present invention are only used to illustrate the relative position relationship and do not represent the true proportion.

[0045] Figure 2 This is a structural schematic diagram of a reflective cup provided by an embodiment of the present invention.

[0046] like Figure 2As shown, in this embodiment of the present invention, the reflector includes a light inlet In and a light outlet Out. The plane where the light inlet In is located is parallel to the plane where the light outlet Out is located, and the area of ​​the light outlet Out is larger than the area of ​​the light inlet In. Between the light inlet In and the light outlet Out are two reflector segments, referred to as a first reflector segment 101 and a second reflector segment 102. The first reflector segment 101 is located on the side close to the light inlet In, and the second reflector segment 102 is located on the side close to the light outlet Out.

[0047] Each reflective cup segment in the reflective cup is surrounded by multiple reflective planes, and the inclination of the two connected reflective planes in different reflective cup segments is different. Figure 2 As shown, the first reflective cup segment 101 is surrounded by a plurality of first reflective planes S1, and the second reflective cup segment 102 is surrounded by a plurality of second reflective planes S2. Each first reflective plane S1 is connected to a second reflective plane S2. The angle between the first reflective plane S1 and the plane where the light inlet In is located is greater than the angle between the second reflective plane S2 and the plane where the light inlet In is located. Therefore, the second reflective cup segment 102 expands outward relative to the first reflective cup segment 101. Taking the plane where the light inlet In is located as a reference, the inclination of the second reflective cup segment 102 is greater than the inclination of the first reflective cup segment 101.

[0048] When the reflective cup is used in a projection device, the light source can be regarded as a point light source. The light beam emitted by the light source 1 gradually diverges, and its light angle range is 0°~θ m According to the different propagation paths of light in the reflector, the light can be regarded as three parts: the first part of light, the second part of light and the third part of light:

[0049] The light output angle range of the first part of the light is 0° to θ1. The first part of the light enters the reflector cup from the light inlet In, propagates linearly inside the reflector cup, and can be directly emitted from the light outlet Out of the reflector cup; the light output angle range of the second part of the light is θ1 to θ2. The second part of the light propagates linearly in the first reflector cup segment 101, and is reflected by the second reflective plane in the second reflector cup segment 102 and then emitted from the light outlet Out of the reflector cup; the light output angle range of the third part of the light is θ2 to θ m After being reflected by the first reflecting plane in the first reflective cup segment 101, the third portion of light propagates in a straight line in the second reflective cup segment 102 and is emitted from the light outlet Out of the reflective cup. The light reflected by the first reflecting plane or the second reflecting plane can be emitted from the light outlet Out of the reflective cup in a direction close to the optical axis L, thereby improving the collimation of the light beam emitted from the light outlet Out of the reflective cup.

[0050] Combine Figure 2It can be seen that when the height of the reflector cup in the direction of the optical axis L is the same, the traditional reflector cup only has a light output angle of θ2~θ m The light of the reflector cup is reflected by the inner wall of the reflector cup and collimated, while the light with an output angle of θ1 to θ2 will propagate in a straight line in the reflector cup and directly emit from the light outlet Out. The second reflector cup segment 102 in the reflector cup provided by the embodiment of the present invention can reflect and collimate the light with an output angle of θ1 to θ2, that is, the light that may originally exit the reflector cup at a large angle is converted to exit at a smaller angle, thereby improving the uniformity of the output light beam and the utilization rate of the light.

[0051] Accordingly, if the light beam emitted by the reflector is to be made equally uniform, the reflector provided by the embodiment of the present invention can have a smaller height than a traditional reflector, which is conducive to the miniaturization of the projection device. In summary, it can be seen that the reflector provided by the embodiment of the present invention can meet the requirements of miniaturization and light beam uniformity.

[0052] like Figure 2 As shown, the height of the first reflector segment 101 along the optical axis L of the reflector is a first height h1, and the height of the second reflector segment 102 along the optical axis L of the reflector is a second height h2, where the first height h1 is greater than the second height h2. The height of each reflector segment in the reflector is designed based on the angular range of the light beam emitted by the light source 1 and the area of ​​the receiving surface. For example, the ratio of the first height h1 to the second height h2 is greater than or equal to 12.

[0053] Exemplarily, the height of the reflective cup in the direction of the optical axis L is greater than or equal to 60 mm, and the height of the reflective cup in the direction of the optical axis L is less than or equal to 65 mm, and the reflective cup as a whole has a relatively small height.

[0054] It is understood that in practical applications, a reflector may include multiple reflector segments. Based on the aforementioned principle, this can convert more light rays emitted at large angles to exit the reflector's light outlet at smaller angles, thereby significantly improving the collimation and uniformity of the emitted light beam. The number of reflector segments in a reflector, as well as the height of each segment, can be designed based on specific needs and are not limited here.

[0055] The inner wall of the reflective cup of the present invention is provided with one or more reflective films made of high reflectivity material to achieve reflection. For example, aluminum metal can be used and processed by rolling, polishing, etc. to make its surface have a mirror effect.

[0056] The reflective cup provided by the present invention is used in a single LCD projection device. The light beam emitted by the reflective cup is projected onto the liquid crystal display panel to form a light spot. The uniformity of the light spot received by the liquid crystal display panel determines the quality of the displayed image. Therefore, the structure of the reflective cup needs to be designed to match the shape of the liquid crystal display panel.

[0057] Liquid crystal display panels typically have a rectangular structure with adjacent sides of different heights. Therefore, the light outlet Out of the reflector in the embodiment of the present invention is designed to be rectangular, with adjacent sides of different heights and opposite sides of the light outlet Out having the same height. This ensures that the light spot projected onto the liquid crystal display panel is a rectangular spot that matches the shape of the liquid crystal display panel. Furthermore, to ensure uniformity of the light spot projected onto the liquid crystal display panel, the reflector is designed to be axisymmetric.

[0058] Specifically, if Figure 2 As shown, the light inlet In and light outlet Out of the reflector are both rectangular. The first reflector segment 101 is enclosed by two first reflective planes having a first area and two first reflective planes having a second area. The first area is smaller than the second area, and the first reflective planes having the same area are symmetrical about the optical axis L of the reflector. The second reflective plane segment 102 is enclosed by two second reflective planes having a third area and two second reflective planes having a fourth area. The third area is smaller than the fourth area, and the second reflective planes having the same area are symmetrical about the optical axis L of the reflector. Furthermore, the first reflective plane having the first area is connected to the second reflective plane having the third area, and the first reflective plane having the second area is connected to the second reflective plane having the fourth area.

[0059] In the embodiment of the present invention, the slope of the reflective plane is used to illustrate the degree of inclination of the reflective plane. The slope of the reflective plane is based on the plane where the light inlet In of the reflective cup is located. The slope satisfies the following relationship: K = |arctanθ|, where K represents the slope of the reflective plane, and θ represents the angle between the reflective plane and the plane where the light inlet In is located.

[0060] It can be seen that in the reflective cup provided by the embodiment of the present invention, the slope of the second reflective plane S2 is greater than the slope of the first reflective plane S1, the slope of the first reflective plane with a relatively smaller area is greater than the slope of the first reflective plane with a relatively larger area, and the slope of the second reflective plane with a relatively smaller area is greater than the slope of the second reflective plane with a relatively larger area. The slope of each reflective plane is described in detail below. The value of the slope of each reflective plane can be calculated using the above relationship.

[0061] Figure 3 A cross-sectional schematic diagram of a reflective cup provided by an embodiment of the present invention.

[0062] Figure 3Shown Figure 2 The cross section in the AA' direction is parallel to the optical axis L of the reflector cup, as shown in Figure 3 As shown, the first reflecting planes S11 and S12 have a first area, and the first reflecting planes S11 and S12 are symmetrical about the optical axis L of the reflective cup, then the slopes of the first reflecting planes S11 and S12 relative to the plane where the light entrance In is located are the same in value but have different signs; the second reflecting planes S21 and S22 have a third area, and the second reflecting planes S21 and S22 are symmetrical about the optical axis L of the reflective cup, then the slopes of the second reflecting planes S21 and S22 relative to the plane where the light entrance In is located are the same in value but have different signs.

[0063] Specifically, the slope K1 of the first reflecting planes S11 and S12 with the first area relative to the plane where the light entrance In is located can satisfy the following relationship: 1.1≤|K1|≤1.6; the slope K2 of the second reflecting planes S21 and S22 with the third area relative to the plane where the light entrance In is located can satisfy the following relationship: 1.78≤|K2|≤2.08.

[0064] Figure 4 A schematic cross-sectional view of another reflective cup provided by an embodiment of the present invention.

[0065] Figure 4 Shown Figure 2 The cross section in the BB' direction is parallel to the optical axis L of the reflector cup, such as Figure 5 As shown, the first reflecting planes S13 and S14 have a second area, and the first reflecting planes S13 and S14 are symmetrical about the optical axis L of the reflective cup, then the slopes of the first reflecting planes S13 and S14 relative to the plane where the light entrance In is located are the same in value but with different signs; the second reflecting planes S23 and S224 have a fourth area, and the second reflecting planes S23 and S24 are symmetrical about the optical axis L of the reflective cup, then the slopes of the second reflecting planes S23 and S24 relative to the plane where the light entrance In is located are the same in value but with different signs.

[0066] Specifically, the slope K3 of the first reflecting planes S13 and S14 with the second area relative to the plane where the light entrance In is located can satisfy the following relationship: 0.3≤|K3|≤0.4; the slope K4 of the second reflecting planes S23 and S24 with the fourth area relative to the plane where the light entrance In is located can satisfy the following relationship: 0.6≤|K4|≤0.7.

[0067] Tests have shown that when the slopes of the reflective surfaces in the reflective cup provided in the embodiment of the present invention meet the aforementioned value ranges, the ANSI nine-point illumination uniformity on the receiving surface can be ensured to be ≥65%, and the four-point illumination uniformity can be ≥55%, while maintaining high light efficiency. This prevents vignetting at the four corners of the receiving surface, which could affect the user's viewing experience. Therefore, applying the reflective cup in the embodiment of the present invention to a single LCD projection device can improve the uniformity of the light spot received by the LCD panel, thereby enhancing the quality of the projected image.

[0068] Based on the same inventive concept, the present invention also provides a projection device, Figure 5 A schematic structural diagram of a projection device provided by an embodiment of the present invention.

[0069] like Figure 5 As shown, the projection device includes a light source 1, a reflector cup 2 and a liquid crystal display panel 3, wherein the reflector cup 2 is located between the light source 1 and the liquid crystal display panel 3, the light source 1 is located on the side close to the light inlet In of the reflector cup 2, and the liquid crystal display panel 3 is located on the side close to the light outlet Out of the reflector cup 2.

[0070] The light source 1 can be an LED light source, for example. The area of ​​the light emitting surface of the light source 1 should be smaller than or equal to the area of ​​the light inlet In of the reflector cup 2, so that all the light emitted by the light source 1 can be incident on the inside of the reflector cup 2, thereby fully utilizing the light and improving the lighting effect.

[0071] The light beam emitted by light source 1 enters the interior of reflector cup 2 from the light inlet In of reflector cup 2. Part of the light is directly emitted from the light outlet Out of reflector cup 2, and part of the light is reflected by the inner wall of reflector cup 2 and emitted from the light outlet Out of reflector cup 2. The light propagation path in reflector cup 2 can be referred to Figure 2 The corresponding description will not be repeated here.

[0072] In some embodiments, the light source 1 may further include a lens 12 or other device to collimate the light beam. Figure 6 This is another schematic diagram of the light path in a reflective cup provided by an embodiment of the present invention. Figure 6 As shown, the light source 1 may include a light emitting device 11 and a lens 12, and the lens 12 covers the light emitting device 11. The lens 12 may refract the light emitted by the light emitting device 11, so that the light is emitted to the reflective cup 2 at a smaller angle, thereby converging the light beam emitted by the light emitting device 11 and then emitting it into the reflective cup 2, thereby improving the collimation and uniformity of the light beam.

[0073] Reference Figure 5 The light beam emitted from the light outlet Out of the reflective cup 2 is projected onto the surface of the liquid crystal display panel 3. The liquid crystal display panel 3 forms a display image by controlling the brightness of the light passing through each color pixel. The display image is formed into a projection image through the projection lens 7.

[0074] The orthographic projection of the light outlet Out of the reflective cup 2 on the liquid crystal display panel 3 should cover the display area of ​​the display panel, so that all parts of the liquid crystal display area can receive the light beam emitted by the reflective cup 2, thereby preventing the liquid crystal display panel 3 from being partially too dark, thereby avoiding missing or blurred displayed images.

[0075] The shape of the light outlet Out of the reflective cup 2 can be the same as the shape of the display area of ​​the liquid crystal display panel 3, so that as much light as possible emitted by the reflective cup 2 is projected onto the liquid crystal display panel 3, while ensuring that the light spot received by the liquid crystal display panel 3 has good uniformity, which is beneficial to improving the brightness and contrast of the displayed image.

[0076] like Figure 5 As shown, a collimating lens 4 may be provided between the reflective cup 2 and the liquid crystal display panel 3 to further improve the collimation of the light beam emitted from the reflective cup 2. The collimating lens 4 may be provided at the light outlet Out of the reflective cup 2 so that the light emitted from the light outlet Out of the reflective cup 2 can completely enter the collimating lens 4 and be utilized.

[0077] To meet the design requirements of miniaturization of the projection device, the projection device may further include a reflective device 5 to fold the light path within the projection device and reduce the size of the projection device. For example, a plane reflector 51 may be provided in the light path between the liquid crystal display panel 3 and the projection lens 7.

[0078] A focusing lens 6 may also be included between the LCD panel 3 and the reflective element 5. The focusing lens 6 can adjust the size of the light beam so that the size of the light spot projected onto the reflective element 5 matches the size of the light incident surface of the reflective element 5, thereby preventing light loss. In some embodiments of the present invention, a focusing lens 6 may also be provided between the reflective element 5 and the projection lens 7 so that the size of the light spot projected onto the projection lens 7 matches the size of the light incident opening of the projection lens 7.

[0079] Figure 7 A schematic structural diagram of another projection device provided by an embodiment of the present invention.

[0080] like Figure 7 As shown, the reflective device can also be a pentagonal prism 52, which is located on the optical path between the liquid crystal display panel 3 and the projection lens 7. The light emitted from the liquid crystal display panel 3 can be reflected multiple times inside the pentagonal prism 52 and then emitted toward the projection lens 7.

[0081] Figure 8 A schematic structural diagram of a pentaangular prism provided in an embodiment of the present invention.

[0082] like Figure 8As shown, the pentagonal prism 52 includes a light incident surface S31 and a light exiting surface S32, two reflecting surfaces S33 and S34, and a connecting surface S35, wherein the light incident surface S31 and the light exiting surface S32 are connected and perpendicular to each other, the two reflecting surfaces are respectively connected to the light incident surface S31 and the light exiting surface S32, and the two reflecting surfaces are set at a set angle, for example, the angle is 45°, and the connecting surface S35 connects the two reflecting surfaces. The light emitted by the liquid crystal display panel 3 is incident from the light incident surface S31 to the inside of the pentagonal prism 52, and can be reflected by the reflecting surfaces S33 and S34 in sequence inside the pentagonal prism 52 and then emitted from the light exiting surface S32 to the projection lens 7.

[0083] Since the light incident surface S31 and the light emitting surface S32 of the pentaprism 52 are perpendicular, no matter at what angle the light enters the pentaprism 52, its exit angle is deflected by 90° relative to its incident angle, thereby avoiding errors during installation and reducing the impact of environmental factors during use, thereby reducing the size of the projection equipment and having higher reliability.

[0084] In this embodiment of the present invention, the penta-prism 52 is made of a light-transmitting material, and a reflective layer is provided on both reflective surfaces. For example, the base material of the penta-prism 52 can be BK7 glass, and both reflective surfaces can be coated with an aluminum film. In practical applications, the light-incident surface S31 and the light-outcending surface S32 of the penta-prism 52 can also be provided with an anti-reflection layer to improve light utilization. A protective layer can also be provided on the side of the reflective layer facing away from the reflective surface and on the connecting surface S35. The protective layer can be made of, for example, black-painted chromium-nickel-inconel alloy.

[0085] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0086] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A reflective cup, characterized in that: The reflective cup comprises at least two reflective cup segments between the light inlet and the light outlet, and the reflective cup segments are surrounded by a plurality of reflective planes; and the inclination degrees of the two connected reflective planes in different reflective cup segments are different.

2. The reflective cup according to claim 1, characterized in that: The reflective cup includes a first reflective cup segment and a second reflective cup segment, wherein the first reflective cup segment is located on a side close to the light entrance, and the second reflective cup segment is located on a side close to the light exit; The first reflective cup segment is surrounded by a plurality of first reflective planes, and the second reflective cup segment is surrounded by a plurality of second reflective planes; each of the first reflective planes is connected to a second reflective plane, and an angle between the first reflective plane and the plane where the light entrance is located is greater than an angle between the second reflective plane and the plane where the light entrance is located.

3. The reflective cup according to claim 2, characterized in that: The height of the first reflective cup segment in the optical axis direction of the reflective cup is a first height, the height of the second reflective cup segment in the optical axis direction of the reflective cup is a second height, and the first height is greater than the second height.

4. The reflective cup according to claim 2, characterized in that: The first reflective cup segment is formed by two first reflective planes with a first area and two first reflective planes with a second area, the first area is smaller than the second area, and the first reflective planes with the same area are symmetrical about the optical axis of the reflective cup; The second reflective cup segment is formed by two second reflective planes with a third area and two second reflective planes with a fourth area, the third area is smaller than the fourth area, and the second reflective planes with the same area are symmetrical about the optical axis of the reflective cup; The first light reflecting plane with the first area is connected to the second light reflecting plane with the third area, and the first light reflecting plane with the second area is connected to the second light reflecting plane with the fourth area.

5. The reflective cup according to claim 4, characterized in that: The first light reflecting plane having the first area and the second light reflecting plane having the third area satisfy the following relationship: 1.1≤|K1|≤1.6； 1.78≤|K2|≤2.08； Wherein, K1 represents the slope of the first light reflecting plane with the first area relative to the plane where the light entrance is located, and K2 represents the slope of the second light reflecting plane with the third area relative to the plane where the light entrance is located.

6. The reflective cup according to claim 4, characterized in that: The first light-reflecting plane having the second area and the second light-reflecting plane having the fourth area satisfy the following relationship: 0.3≤|K3|≤0.4； 0.6≤|K4|≤0.7； Among them, K3 represents the slope of the first light reflecting plane with the second area relative to the plane where the light entrance is located, and K4 represents the slope of the second light reflecting plane with the fourth area relative to the plane where the light entrance is located.

7. The reflective cup according to claim 3, characterized in that: A ratio of the first height to the second height is greater than or equal to 12.

8. The reflective cup according to claim 7, characterized in that: The height of the reflective cup in the direction of the optical axis is greater than or equal to 60 mm, and the height of the reflective cup in the direction of the optical axis is less than or equal to 65 mm.

9. A projection device, characterized in that: The projection device includes a light source, a liquid crystal display panel and a reflective cup as described in any one of claims 1 to 8; the reflective cup is located between the light source and the liquid crystal display panel, the light source is located on a side close to a light entrance of the reflective cup, and the liquid crystal display panel is located on a side close to a light exit of the reflective cup.

10. The projection device according to claim 9, characterized in that: The orthographic projection of the light outlet of the reflective cup on the liquid crystal display panel covers the display area of ​​the display panel.

11. The projection device according to claim 10, characterized in that: The shape of the light outlet of the reflective cup is the same as the shape of the display area of ​​the liquid crystal display panel.

12. The projection device according to claim 9, characterized in that: The light source comprises a light emitting device and a lens. The lens covers the light emitting device and is used for converging the light beam emitted by the light emitting device and emitting it into the reflective cup.

13. The projection device according to any one of claims 9 to 12, characterized in that: The projection device also includes a pentagonal prism and a projection lens. The pentagonal prism is located on the optical path between the liquid crystal display panel and the projection lens. The light emitted from the liquid crystal display panel is reflected multiple times inside the pentagonal prism and then emitted toward the projection lens.

14. The projection device according to claim 13, characterized in that: The pentagonal prism comprises a light incident surface, a light emitting surface, two light reflecting surfaces and a connecting surface, wherein the light incident surface and the light emitting surface are connected and perpendicular to each other, the two light reflecting surfaces are respectively connected to the light incident surface and the light emitting surface, and the two light reflecting surfaces are arranged at a set angle, and the connecting surface connects the two light reflecting surfaces; The light emitted from the liquid crystal display panel is incident on the inside of the pentagonal prism from the light incident surface, and is emitted from the light emitting surface to the projection lens after being reflected by the two light reflecting surfaces inside the pentagonal prism.

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