Projection system

Abstract

This application discloses a projection system, belonging to the field of projection equipment. The projection system includes a light source assembly, an illumination assembly, a lens assembly, and a screen arranged sequentially along the optical path. The lens assembly includes a first mirror group, a first reflector, a second mirror group, and a second reflector. The first mirror group receives the light beam emitted from the illumination assembly and guides the beam to the first reflector. The second mirror group receives the light beam reflected from the first reflector and guides the beam to the second reflector. The second reflector guides the beam to the screen. In the projection system provided by this application, the lens assembly includes a first reflector. This first reflector deflects the optical axes of the first and second mirror groups in the two lens assemblies, reducing the maximum size of the lens assembly and thus reducing the size of the projection system. This solves the problem of large projection system size in related technologies and achieves the effect of reducing the size of the projection system.

Description

[0001] This application claims priority to Chinese Patent Application No. 202011025334.6, filed on September 25, 2020, entitled “Projection System”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of projection equipment, and in particular to a projection system. Background Technology

[0003] Projection televisions are a rapidly developing type of television in recent years, boasting advantages such as large image size, high spectral brightness, and a wide color gamut. The projection system of a projection television includes an optical engine and a screen. The optical engine comprises a light source assembly, an illumination assembly, and a lens assembly. The size of the optical engine is a crucial factor influencing the widespread application of projection televisions.

[0004] An optical engine for a projection system includes a light source, an illumination component, and a lens. A light beam emitted by the light source is directed toward the illumination component, which processes the light beam and guides it toward the lens. The optical axis of the lens is perpendicular to the screen, and the lens is capable of guiding the received light beam toward the screen of a projection television.

[0005] However, the lens in the optical engine of the aforementioned projection system is relatively long, which may result in a larger optical engine size, and consequently a larger projection system size. Summary of the Invention

[0006] This application provides a projection system. The technical solution is as follows:

[0007] According to a first aspect of this application, a projection system is provided, the projection system comprising a light source assembly, an illumination assembly, and a lens assembly arranged sequentially along the optical path direction;

[0008] The lens assembly includes a first lens group, a first reflector, a second lens group, and a second reflector. The first lens group is used to receive the light beam emitted by the illumination assembly and guide the light beam to the first reflector. The second lens group is used to receive the light beam reflected by the first reflector and guide the light beam to the second reflector. The second reflector is used to guide the light beam to the screen. The maximum distance between the first lens group and the second lens group is less than the sum of the lengths of the first lens group and the second lens group.

[0009] Optionally, the optical axis of the second mirror group is perpendicular to the screen.

[0010] Optionally, the optical axis of the first mirror group is perpendicular to the optical axis of the second mirror group.

[0011] Optionally, the lighting assembly includes a third reflector, a light homogenizer, a light valve, a prism unit, a first lens unit, and a second lens unit;

[0012] The light-diffusing device is used to uniformly distribute the light beam emitted by the light source assembly and direct the light beam toward the first lens unit.

[0013] The first lens unit is used to shape the received light beam and direct the light beam toward the third reflecting mirror;

[0014] The third reflecting mirror is used to reflect the received light beam toward the second lens unit;

[0015] The second lens unit is used to guide the received light beam to the prism unit after ensuring that the received light beam meets the aperture coefficient of the lens assembly;

[0016] The prism unit is used to guide the light beam received from the second lens unit to the light valve and to export the light beam reflected by the light valve to the illumination assembly.

[0017] Optionally, the first plane determined by the straight line where the optical axis of the lighting component lies before being reflected by the light valve and the straight line where the optical axis of the lighting component lies after being reflected by the light valve is not coplanar with the second plane determined by the optical axis of the first mirror group and the optical axis of the second mirror group.

[0018] Optionally, the first plane is perpendicular to the second plane.

[0019] Optionally, the lighting assembly includes a light valve circuit board electrically connected to the light valve, and the projection system includes a display panel electrically connected to the light valve circuit board.

[0020] Optionally, the display panel is electrically connected to the light valve circuit board via a straight cable.

[0021] Optionally, the display panel is parallel to the screen and perpendicular to the light valve.

[0022] Optionally, the display panel is located on the side of the lens assembly closer to the screen;

[0023] The light valve circuit board and the lens assembly are arranged along a first direction, which is parallel to the screen. The light valve is used to flip under the drive of the light valve control signal and transmit the light beam to the lens assembly.

[0024] Optionally, the projection system further includes a base plate, and the straight cable includes differential signal lines; the display panel, light valve circuit board, and lens assembly are all located on the base plate, and the differential signal lines are in contact with the base plate.

[0025] Optionally, the projection system further includes: a shielding layer;

[0026] The shielding layer is wrapped around the outside of the differential signal line, and the shielding layer is grounded.

[0027] Optionally, the projection system further includes a magnetic ring, which is sleeved on the outside of the shielding layer, and the length of the magnetic ring is less than the length of the shielding layer.

[0028] Optionally, the projection system further includes: a common-mode inductor;

[0029] The common-mode inductor is connected in series between the display panel and the light valve circuit board via the differential signal line.

[0030] Optionally, the distance between the display panel and the light valve circuit board is determined based on the communication rate between the light valve driving component in the display panel and the light valve.

[0031] Optionally, the communication rate between the light valve driving assembly and the light valve is less than or equal to 1.6 gigabits per second, and the distance between the display panel and the light valve circuit board is less than or equal to 254 millimeters.

[0032] The beneficial effects of the technical solutions provided in this application include:

[0033] A projection system including a light source assembly, an illumination assembly, a lens assembly, and a screen is provided. The lens assembly is provided with a first reflector, which deflects the optical axes of the first and second lens groups in the two lens assemblies, thereby reducing the maximum size of the lens assembly and thus reducing the size of the projection system. This solves the problem of the large size of projection systems in related technologies and achieves the effect of reducing the size of the projection system. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of a projection system.

[0036] Figure 2 This is a schematic diagram of the structure of a projection system provided in an embodiment of this application;

[0037] Figure 3 This is a schematic diagram of another projection system provided in an embodiment of this application;

[0038] Figure 4 yes Figure 3 A schematic diagram of a light valve assembly in the projection system shown;

[0039] Figure 5 This is a partial three-dimensional structural schematic diagram of a projection system according to an embodiment of this application;

[0040] Figure 6 This is a partial three-dimensional structural diagram of another projection system in an embodiment of this application;

[0041] Figure 7 This is a schematic diagram of the structure of a projection television provided in an embodiment of this application;

[0042] Figure 8 yes Figure 7 The diagram shows a top view of the projection television structure.

[0043] Figure 9 This is a schematic diagram of another projection television provided in an embodiment of this application;

[0044] Figure 10 This is a schematic diagram of the connection between a display panel and a light valve driver board provided in an embodiment of this application;

[0045] Figure 11 This is a schematic diagram of a differential signal line wrapped with a shielding layer and a magnetic ring sleeved on the shielding layer, provided in an embodiment of this application;

[0046] Figure 12 This is a schematic diagram of a first circuit board with a common-mode inductor provided in an embodiment of this application;

[0047] Figure 13 This is a schematic diagram of a second circuit board with a common-mode inductor provided in an embodiment of this application;

[0048] Figure 14 This is a schematic diagram of another projection system provided in an embodiment of this application;

[0049] Figure 15 This is a partial schematic diagram of a second circuit board provided in an embodiment of this application;

[0050] Figure 16 This is a partial schematic diagram of a second circuit board provided in an embodiment of this application;

[0051] Figure 17 This is a schematic diagram illustrating the results of a low-frequency radiated disturbance field strength test on a projection system, provided in an embodiment of this application.

[0052] Figure 18This is an eye diagram of a light valve receiving a differential signal transmitted by a light valve drive component, provided in an embodiment of this application.

[0053] Figure 19 This is a schematic diagram of another projection system provided in an embodiment of this application.

[0054] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0056] The structure of a projection system can be as follows: Figure 1 As shown, the projection system includes a light source 11, an illumination assembly 12, and a lens 13. The light beam emitted by the light source 11 is shaped by the illumination assembly 12 and then directed to the lens 13. The lens 13 includes a transmission lens group 131 and a reflector 132. The optical axis of the transmission lens group 131 is perpendicular to the screen 02. The light beam emitted by the illumination assembly 12 passes through the lens group 131 and is then guided by the transmission lens group 131 to the reflector 132. The reflector 132 reflects the light beam onto the screen 02 of the projection television.

[0057] Depend on Figure 1 It can be seen that the size L of the projection system in the direction f perpendicular to the screen 02 is composed of the size of the connection between the lighting component 12 and the lens 13 and the length of the lens 13. The overall size is relatively large, which makes the overall size of the projection system in the direction f perpendicular to the screen 02 relatively large, which is not conducive to the miniaturization of projection TVs.

[0058] In addition, for lenses with a small throw ratio (the ratio of the distance from the lens reflector to the screen to the width of the projected image), the projection system is unable to fully realize its throw ratio advantage due to the limitation of size L.

[0059] For example, the lens has a throw ratio of 0.17, a projection size of 75 inches, a minimum distance of 282.3 mm from the reflector 14 to the screen 02, and a lens length of 270 mm. Considering the size of the light valve, the structure of this projection system is obviously unable to take advantage of the lens's low throw ratio, thus wasting the manpower and resources spent on lens design.

[0060] This application provides a projection system that can solve some of the problems mentioned above.

[0061] Figure 2This is a schematic diagram of a projection system provided in an embodiment of this application. The projection system 20 may include a light source assembly 21, an illumination assembly 22, a lens assembly 23, and a screen 31 arranged sequentially along the light path direction.

[0062] The lens assembly 23 includes a first lens group 231, a first reflector 232, a second lens group 233, and a second reflector 234. The first lens group 231 is used to receive the light beam emitted by the illumination assembly 22 and guide the light beam to the first reflector 232. The second lens group 233 is used to receive the light beam reflected by the first reflector 232 and guide the light beam to the second reflector 234. The second reflector 234 is used to guide the light beam to the screen 31. The maximum distance between the first lens group 231 and the second lens group 233 is less than the sum of the lengths of the first lens group 231 and the second lens group 233.

[0063] In this design, the optical axes of the first lens group 231 and the second lens group 233 are not parallel, and are deflected by the first reflecting mirror 232, making the maximum size of the lens assembly 23 smaller than the sum of the lengths of the first lens group 231 and the second lens group 23. This reduces the maximum size of the lens assembly 23, allowing the projection system to be smaller in the direction perpendicular to the screen when applied to a projection TV. This also demonstrates the advantage of the smaller projection size of the lens assembly, making the projection TV thinner and more aesthetically pleasing, and providing a better user experience.

[0064] In summary, this application provides a projection system including a light source assembly, an illumination assembly, a lens assembly, and a screen. The lens assembly includes a first reflector, which deflects the optical axes of the first and second lens groups in the lens assembly, thereby reducing the maximum size of the lens assembly and consequently reducing the size of the projection system. This solves the problem of large projection system size in related technologies and achieves the effect of reducing the size of the projection system. Simultaneously, the illumination and light source system are designed in conjunction with this design to optimize the size of the engine system.

[0065] Figure 3 This is a schematic diagram of another projection system provided in an embodiment of this application. The projection system in... Figure 2 Some adjustments were made to the projection system shown.

[0066] Optionally, the optical axis x2 of the second lens group 233 is perpendicular to the screen 31. In this structure, the second reflector 234 is positioned directly opposite the screen 31, and the light beam reflected by the second reflector 234 onto the screen 31 forms an image. The second reflector 234 can not only fold the optical path, but also magnify and reshape the optical path, reducing the design difficulty of ultra-short focal length lenses.

[0067] Optionally, the optical axis of the first mirror group 231 (in) Figure 3 In the middle, the optical axis of the first mirror group 231 is parallel to the direction f2) and the optical axis of the second mirror group 233 is parallel to the direction f2. Figure 3 In this configuration, the optical axis of the second lens group 231 is parallel to and perpendicular to the direction f1. This structure significantly reduces the overall size of the lens assembly 23, allowing for a smaller maximum distance between the first and second lens groups 231. Furthermore, this structure ensures that the optical axis of the first lens group 231 is parallel to the screen 31, facilitating its placement within the projection system.

[0068] Optionally, such as Figure 4 As shown, it is Figure 3 The projection system shown is a schematic diagram of the structure of the illumination component 22 along direction f1. The illumination component 22 includes a third reflector 221, a light homogenizer 222, a light valve 223, a prism unit 226, a first lens unit 224, and a second lens unit 225.

[0069] The light homogenizing device 222 is used to homogenize the light beam emitted by the light source assembly 21 and direct the light beam toward the first lens unit 224.

[0070] The first lens unit 224 is used to shape the received light beam and direct the light beam toward the third reflecting mirror 221.

[0071] The third reflector 221 is used to reflect the received light beam toward the second lens unit 225. This third reflector 221 can fold the illumination light path, satisfying the light input requirements of the light valve and adjusting the relative positions of the light source, illumination assembly, and lens assembly, thereby optimizing the size of the projection system.

[0072] The second lens unit 225 is used to guide the received light beam to the prism unit 226 after ensuring that the aperture coefficient of the lens assembly 23 is met.

[0073] Prism unit 226 is used to guide the light beam received from second lens unit 225 to light valve 223 and to guide the light beam reflected by light valve 223 out of illumination assembly 22. The prism unit 226 may include a total internal reflection prism (TIR).

[0074] Optionally, the light homogenizing device 222 includes a light guide, which is a tubular device made up of four planar reflective sheets, also known as a hollow light guide. Light is reflected multiple times inside the light guide to achieve the effect of light homogenization. The light guide can also be a solid light guide. The light inlet and light outlet of the light guide are rectangles with the same shape and area. The laser beam enters from the light inlet of the light guide and then shines on the light valve assembly from the light outlet of the light guide. During the process of passing through the light guide, the beam homogenization and light spot optimization are completed.

[0075] Alternatively, the homogenizing device 222 may also include a compound eye lens, which is typically formed by a series of small lenses. Two parallel arrays of compound eye lenses are arranged to segment the light spot of the input laser beam. The segmented light spots are then accumulated by a subsequent focusing lens, thereby achieving beam homogenization and spot optimization. In an illumination device, the homogenizing device 222 may be selected from at least one of a light guide or a compound eye lens; this embodiment of the application does not limit the selection.

[0076] A digital micromirror device (DMD) is a type of digital micromirror element. A DMD can comprise an array of multiple high-speed digital light-reflecting switches. For example, a DMD may include multiple small mirrors, with one mirror corresponding to one pixel. The number of mirrors determines the display resolution of the DMD.

[0077] The light valve can be 2K resolution, 3K resolution or higher resolution, and this application embodiment does not limit it.

[0078] Optionally, the first plane defined by the straight line where the optical axis of the lighting component lies before being reflected by the light valve and the straight line where the optical axis of the lighting component lies after being reflected by the light valve (this first plane is the plane with...) Figure 4 The plane parallel to the paper shown) and Figure 3 The second plane determined by the optical axis of the first lens group 231 and the optical axis of the second lens group 233 (this second plane is the plane that is perpendicular to the optical axis of the first lens group 231) is the plane that is perpendicular to the optical axis of the second lens group 233. Figure 3 The planes parallel to the paper shown are not coplanar. The first and second planes are not coplanar, which can further reduce the projection system's position in the direction f1 perpendicular to the screen 31 (for lens assembly 23). Figure 3 The direction f1 shown is the dimension in the direction perpendicular to the screen 31 and towards the screen.

[0079] Optionally, the first plane is perpendicular to the second plane. With the first plane perpendicular to the second plane, the light valve assembly will not affect the size of the projection system in the direction f1 perpendicular to the screen 31, further reducing the size of the projection system in the direction f1 perpendicular to the screen 31.

[0080] like Figure 1As shown, in the illumination assembly, the light valve 121 and the lens 13 are sequentially arranged in the direction f perpendicular to the screen 02. The light valve 121 is parallel to the screen 02 and together they constitute the main components in the direction f perpendicular to the screen 02, thus making the size of the projection system larger in the direction f perpendicular to the screen 02. However, in the projection system provided in this embodiment, the first plane where the light path of the light valve assembly is located is set to be perpendicular to the second plane where the light path of the lens assembly is located, avoiding the influence of the light valve assembly on the size of the projection system and achieving the technical effect of further reducing the size of the projection system in the direction f1 perpendicular to the screen 31.

[0081] Optionally, such as Figure 3 As shown, the projection system provided in this embodiment of the application also includes a galvanometer 24. The galvanometer 24 may include an optical lens and a driving component. The driving component can drive the optical lens to oscillate continuously around a preset rotation axis, and the optical lens can change the direction of the light beam accordingly.

[0082] For example, when the light beam incident on the galvanometer is a parallel beam (i.e., each ray in the beam has the same angle of incidence), after the optical lens in the galvanometer swings from one position to another, the displacement distance of each pixel in the projected image corresponding to the image beam is equal, making the offset of each field of view in the projection lens from the projection screen consistent, thus ensuring high-resolution display of the visual image. Here, the offset of the field of view refers to the actual displacement distance of the field of view. This invention places the galvanometer between the total internal reflection prism (TIR) ​​of the second lens unit in the illumination assembly and the last lens of the lens assembly. The illumination assembly adopts a telecentric scheme, so the light beam emitted from the galvanometer is parallel. The 2K or 3K resolution can be converted to 4K resolution by rotating the galvanometer, reducing the complexity of system design.

[0083] With the application of a galvanometer, a 2K resolution light valve can achieve 4K resolution when used in conjunction with the galvanometer. A 3K resolution light valve can also achieve 4K resolution when used in conjunction with the galvanometer. The light valve can be controlled by the control circuit in the display panel and DMD board, reflecting the light beam incident on the light valve into the projection lens assembly 23 to generate an imaging beam. The image projected onto the screen by this imaging beam is the video image.

[0084] Optionally, such as Figure 3 As shown, the projection system also includes a display panel 25, which is electrically connected to the PCB board of the light valve 223. The display panel 25 may include control circuitry for controlling the light valve 223.

[0085] In this embodiment, the position of the light valve 223 is adjusted, and consequently the position of the display panel 25 is also adjusted accordingly.

[0086] Optionally, the display panel 25 is parallel to the screen plane and perpendicular to the light valve 223 (that is, the display panel 25 is perpendicular to the plane containing the optical axes of the first mirror group 231 and the second mirror group 233). With this structure, the display panel 25 can be located relatively close to the light valve, preventing the connection between the display panel 25 and the light valve 223 from becoming too long; furthermore, the display panel 25 will not obstruct or interfere with the light beam reflected from the second reflector 234 to the screen 31. Since the space on the side of the projection system closest to the screen 31 is larger, the display panel 25 can be located on this side of the projection system.

[0087] For example, such as Figure 5 The diagram shown is a partial three-dimensional structural schematic of a projection system according to an embodiment of this application. The display panel 25 is parallel to the screen and perpendicular to the light valve 223.

[0088] Optionally, the lighting assembly includes a light valve circuit board 227 (which can be a printed circuit board, PCB) electrically connected to the light valve. The light valve circuit board 227 is stacked with the light valve 223 and is used to control the light valve 223. The display panel 25 is electrically connected to the light valve circuit board 227 via a straight cable 251. If the wires between the display panel 25 and the light valve circuit board 227 are bent, it may damage the light valve or cause problems with the displayed image, increasing reliability risks. However, in the projection system provided in this application embodiment, connecting the display panel 25 and the light valve circuit board 227 via a straight cable can avoid damage to the light valve 223 and improve its service life.

[0089] Figure 5 The illustration shows the display panel 25 electrically connected to the light valve circuit board 227 via two straight cables. However, the display panel 25 can also be electrically connected to the light valve circuit board 227 via fewer (e.g., one row) or more straight cables (e.g., three rows, four rows, six rows, etc.). This embodiment does not limit this.

[0090] Optionally, the display panel measures 112 mm x 210 mm x 20 mm.

[0091] like Figure 6 The diagram shown is a partial three-dimensional structural schematic of another projection system according to an embodiment of this application. The display panel 25 is electrically connected to the light valve circuit board 227 via a straight cable. Furthermore, the display panel 25 is parallel to the screen and perpendicular to the light valve 12.

[0092] Optionally, the display panel 25 has an external port for connecting to an external device to receive video signals transmitted by the external device. Exemplarily, the projection system also includes a control motherboard through which the display panel 25 receives video signals transmitted by the control motherboard.

[0093] Optionally, such as Figure 3 As shown, the light source assembly 21 includes a laser light source 211, a laser, a telescope system, a fluorescent light path, and a blue light path.

[0094] Compared to LED light sources, laser light sources can achieve a higher color gamut. This invention patent exemplarily uses a monochromatic laser light source, but is not limited to laser light sources.

[0095] Optionally, the light source assembly 21 further includes a light conversion unit 213, which receives laser light from the laser source 211 and converts the laser light into visible light of various colors to provide to the lighting assembly 22. For example, the light source assembly 21 is used to provide visible light, such as light in the red band, light in the green band, and light in the blue band, or to provide light in the red band, light in the green band, light in the blue band, and light in the yellow band.

[0096] The projection system provided in this application embodiment can reduce its size in the direction perpendicular to the screen, thereby reducing the size of the projection system while also reserving margin for the overall system design.

[0097] Please refer to Figure 3 In one exemplary embodiment, the lenses arranged along direction f2 in the first lens group 231 are a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens, wherein the third lens, the fourth lens, and the fifth lens constitute a cemented triplet lens; and the eighth lens and the ninth lens constitute a cemented doublet lens.

[0098] The optical power of the first, second, third, sixth, and seventh lenses is positive, while the optical power of the fourth, fifth, eighth, and ninth lenses is negative.

[0099] The second lens is an aspherical lens, which can correct astigmatism and coma in the lens assembly, reducing the aberration correction burden on subsequent lenses. The second lens can be made of a material with a low refractive index and a low melting point. The other lenses besides the second lens can be spherical lenses.

[0100] Please refer to Figure 3 In one exemplary embodiment, the lenses arranged in the second lens group 233 in the opposite direction of direction f1 are the tenth lens, the eleventh lens, the twelfth lens, and the thirteenth lens. The tenth lens is a spherical lens with positive optical power. The eleventh and twelfth lenses are spherical lenses, and the thirteenth lens is an aspherical lens. The eleventh, twelfth, and thirteenth lenses can be used to correct image distortion. The eleventh lens has positive optical power, and the twelfth and thirteenth lenses have negative optical power.

[0101] In summary, the embodiments of this application provide a projection system including a light source assembly, an illumination assembly, a lens assembly, and a screen. The lens assembly is provided with a first reflector, which deflects the optical axes of the first and second lens groups in the two lens assemblies, thereby reducing the maximum size of the lens assembly and thus reducing the size of the projection system. This solves the problem of the large size of projection systems in related technologies and achieves the effect of reducing the size of the projection system.

[0102] In addition, such as Figure 7 As shown, it is a structural schematic diagram of a projection television 30 provided in an embodiment of this application. The projection television 30 includes any of the projection systems 20 provided in the above embodiments.

[0103] Optionally, the projection television 30 includes a cabinet 31, which includes a first accommodating portion 31a and a second accommodating portion 31b. The cross-section of the second accommodating portion 31b is L-shaped, and the first accommodating portion 31a is located on the stepped surface of the second accommodating portion 31b.

[0104] The projection system 20 is located in the first accommodating part 31a. The top surface of the first accommodating part 31a has a light-transmitting area t, through which the projection system 20 can emit a light beam and pass through the light-transmitting area t.

[0105] Optionally, the projection TV 30 also includes functional components ( Figure 7 (Not shown in the image), the functional components are used to cooperate with the projection system 20 so that the projection system 20 can emit a light beam.

[0106] Optionally, the screen 4 includes a roll-up assembly 41, a lifting assembly 42, and a screen panel 43; the roll-up assembly 41 is rotatably fixed inside the second receiving portion 31b and located below the stepped surface of the second receiving portion 31b; the first side of the screen panel 43 is fixedly connected to the roll-up assembly 41; the roll-up assembly 41 can control the screen panel 43 to be received in the inner cavity of the second receiving portion 31b; the lifting assembly 42 is fixed inside the second receiving portion 31b and arranged horizontally with the roll-up assembly 41; the second side of the screen panel 43 is fixedly connected to the lifting assembly 42; the top surface of the second receiving portion 31b has an opening 31b1; the lifting assembly 42 can control the screen panel 43 to pass through the opening 31b1 and unfold; when the screen panel 43 is unfolded, it receives a light beam; the first side and the second side are opposite to each other.

[0107] In this embodiment, when the projection device is not in use, the screen 43 passes through the opening 31b1 under the control of the roll-up assembly 41 and is housed within the cavity of the second receiving portion 31b, thereby reducing the overall size of the projection device. When the projection device is in use, the screen 43 passes through the opening 31b1 and unfolds under the control of the lifting assembly 42, thereby receiving the light beam emitted by the projection system 3 and achieving normal image display. Furthermore, the first receiving portion 11 and the second receiving portion 31b limit the positioning of the projection system 3 and the screen 43, achieving integration of the projection system 3 and the screen 43, avoiding relative displacement between the projection system 3 and the screen 43, and ensuring the display effect of the image on the screen 43. In addition, the L-shaped design of the second receiving portion 31b allows the roll-up assembly 41 to be located below the projection system 3. Thus, the overall height of the projection device mainly depends on the height of the roll-up assembly 41 and the height of the projection system 3, thereby reducing the height requirement for the lifting assembly 42 when it is retracted. When the screen 43 is rolled up by the rolling assembly 41, the more turns it makes, the greater the possibility of creases or other defects in the screen 43. Therefore, to ensure the flatness of the screen 43, the rolling diameter of the rolling assembly 41 is set to be slightly larger. With a slightly larger rolling diameter, the rolling assembly 41 is positioned below the projection system 3, thereby avoiding any impact on the overall width of the projection device.

[0108] The center point of the screen 43 is located on the main optical axis of the beam emitted from the projection system 20, so that the display image formed by the beam emitted from the projection system 20 on the screen 43 is centered, thus ensuring the display effect of the screen 43.

[0109] The lifting assembly 42 includes a lifting frame 421 and a crossbeam 422. One end of the lifting frame 421 is connected to the second receiving portion 31b, and the second end of the lifting frame 421 is connected to the crossbeam 422. The second side of the curtain panel 43 is also connected to the crossbeam 422. In this way, the lifting frame 421 can lift the crossbeam 422, thereby causing the curtain panel 43 to unfold.

[0110] The projection system 20 provided in this application embodiment deflects a portion of the lens assembly by using a reflector disposed between the first and second lens groups in the lens assembly. In addition, the position of the light valve assembly is also deflected at any time, which greatly compresses the size L1 of the projection system in the direction f1 perpendicular to the screen 31. As a result, the thickness of the projection TV in the direction f1 perpendicular to the screen 31 is thinner, reducing the space occupied by the projection TV and greatly improving the user experience.

[0111] Please refer to Figure 8 , Figure 8 yes Figure 7The diagram shows a top view of the projection television. The projection television 30 also includes a control motherboard 26 and a power board 27. The control motherboard 26 is electrically connected to the power board 27 and the display panel in the projection system 20, respectively.

[0112] The control motherboard 26 is the motherboard for the projection TV, and its connectors can be used to connect external devices such as computers, mobile phones, and USB flash drives. In this way, the control motherboard can receive audio and video signals transmitted from these devices, decode them to obtain video signals, and then transmit the video signals to the display panel.

[0113] The control motherboard 26 is located on the right side of the projection system 20, and correspondingly, the connection port is located on the right side of the first accommodating part 31a in the length direction f2 (which is parallel to the screen 4).

[0114] Based on the above description, the first receiving part 31a has a first shelf below it. When the connection port is located on the bottom side of the first receiving part 31a, the external device connected to the plug end is placed on the first shelf, thereby ensuring the privacy of the external device and avoiding the possibility of external objects colliding with the external device.

[0115] Optionally, the first receiving portion 31a has a cover plate that is rotatably connected to the edge of the connection port. In this way, when the plug-in terminal of the control motherboard 26 is not in use, the connection port is closed by the cover plate, thereby avoiding the continuous exposure of the plug-in terminal and achieving effective protection of the plug-in terminal.

[0116] Optionally, the projection television 30 also includes a second support frame, which is fixed within the first receiving portion 31a, and the control motherboard 23 is fixed on the second support frame. In this way, based on the separate provision of the first support frame for the projection system 20 as described above, the second support frame can be optimized without affecting the projection system 20. For example, the height of the second support frame can be adjusted, or its load-bearing area can be adjusted.

[0117] Optionally, the projection television 30 also includes a remote controller, which is electrically connected to the control motherboard 26 and fixed to the second support frame. The remote controller can determine the remote control signal and transmit the determined remote control signal to the control motherboard 26, so that the control motherboard 26 can control the switching of the display image projected by the projection system 20 based on the remote control signal. Since the remote controller is fixed to the second support frame, the load-bearing area of ​​the second support frame can be adjusted based on the control motherboard 26 and the remote controller.

[0118] The remote control includes buttons, which are electrically connected to the control motherboard 26. This allows the remote control to detect user button presses and determine the corresponding remote control signal. The buttons include a power button, volume buttons, and screen switching buttons; these buttons can be physical or virtual.

[0119] Optionally, the projection television 30 also includes a wireless module located within the cavity of the first accommodating portion 31a. The wireless module is electrically connected to the control motherboard 26 and is fixed to the second support frame. With the wireless module fixed to the second support frame, the load-bearing area of ​​the second support frame can be adjusted based on the control motherboard 26 and the wireless module.

[0120] The wireless module includes a Bluetooth module and / or a Wi-Fi (Wireless-Fidelity) module. The Wi-Fi module is used to connect the projection device to the wireless internet, and then transmit the audio data transmitted via the wireless internet to the control motherboard 26.

[0121] Optionally, the projection television 30 also includes a speaker 28, which is located inside the cavity of the first accommodating part 31a and is electrically connected to the control main board 26. The first accommodating part 31a has a sound port on the side away from the second accommodating part 31b, and the sound outlet of the speaker 28 faces the sound port.

[0122] In this embodiment of the application, the direction parallel to the screen may refer to the direction parallel to the screen when the screen is unfolded.

[0123] In addition, such as Figure 9 As shown, it is Figure 7 The diagram shows a three-dimensional representation of a projection television. The projection system can be located within cabinet 31. Figure 9 The diagram shows the structure of the screen 43 when it is raised by the beam 422, and the beam s emitted by the projection system can project images onto the screen 43.

[0124] In summary, the embodiments of this application provide a projection system including a light source assembly, an illumination assembly, a lens assembly, and a screen. The lens assembly is provided with a first reflector, which deflects the optical axes of the first and second lens groups in the two lens assemblies, thereby reducing the maximum size of the lens assembly and thus reducing the size of the projection system. This solves the problem of the large size of projection systems in related technologies and achieves the effect of reducing the size of the projection system.

[0125] refer to Figure 10 and Figure 11The projection system may also include a differential signal line 50 and a base plate 60. The display panel 25, the light valve circuit board 227, and the lens assembly are all located on the base plate 60. The differential signal line 50 is in contact with the base plate 60, and the base plate 60 is grounded. The base plate 60 may be made of a metallic material, such as iron.

[0126] The display panel 25 and the light valve circuit board 227 are electrically connected via a differential signal line 50. The display panel 25 can provide a light valve control signal to the light valve 223 in the light valve circuit board 227 via the differential signal line 50.

[0127] Optionally, the differential signal line 50 can be a low-voltage differential signaling (LVDS) line. The display panel 25 can transmit control signals to the light valve 223 in LVDS format. This control signal can include differential-mode and common-mode signals. The differential-mode signal is the aforementioned light valve control signal, used to control the light valve's toggle. The common-mode signal is not used to control the light valve 223's toggle. Since the base plate 60 is grounded and the differential signal line 50 is in contact with the base plate 60, the common-mode signal transmitted through the differential signal line 50 can be grounded, preventing the common-mode signal from radiating to the outside of the housing and affecting the user.

[0128] refer to Figure 11 The projection system may also include a shielding layer 70, which wraps around the outside of the differential signal line 50 and is grounded.

[0129] Optionally, both ends of the shielding layer 70 can be grounded, or only one end can be grounded. The material of the shielding layer 70 can be a metallic material, such as red copper or tin-plated copper. The shielding layer 70 can be a mesh-like braided layer.

[0130] Because the shielding layer 70 encloses the differential signal line 50 and is grounded, the common-mode signal transmitted by the differential signal line 50 can be conducted to the ground through the shielding layer 70. This effectively shields the common-mode signal within the projection system, preventing excessive radiation of the common-mode signal transmitted by the differential signal line to the outside of the housing 00, thus minimizing the impact on the user. Simultaneously, it ensures that the common-mode interference of the projection system meets electromagnetic compatibility limits, ensuring that the projection system passes electromagnetic interference (EMI) testing, thereby guaranteeing the projector's qualification.

[0131] refer to Figure 11The shielding layer 70 is connected to the base plate 60. Since both the shielding layer 70 and the base plate 60 are made of metal, and the base plate 60 is grounded, connecting the shielding layer 70 to the base plate 60 allows the shielding layer 70 to be grounded.

[0132] Optionally, both ends of the shielding layer 70 can be directly connected to the base plate 60. Alternatively, both ends of the shielding layer 70 can be connected to the base plate 60 via metal wires. Alternatively, one end of the shielding layer 70 can be directly connected to the base plate 60, and the other end of the shielding layer 70 can be connected to the base plate 60 via metal wires.

[0133] In one optional implementation of the embodiments of this application, reference is made to... Figure 11 The projection system may also include a magnetic ring 80, which is sleeved on the outside of the shielding layer 70, and the length of the magnetic ring 80 is less than the length of the shielding layer 70, that is, the magnetic ring 80 only covers a portion of the shielding layer 70. By sleeved the magnetic ring 80 on the outside of the shielding layer 70, the impedance on the common-mode current transmission path can be increased, that is, the impedance of the differential signal line 50 can be increased, thereby effectively suppressing the common-mode signal, reducing the common-mode current on the differential signal line, and thus reducing the common-mode signal radiated to the outside of the housing.

[0134] In another optional implementation of this application embodiment, the projection system may further include a common-mode inductor, which is connected in series between the display panel 25 and the light valve circuit board 227 via a differential signal line 50. By connecting the common-mode inductor in series between the display panel 25 and the light valve circuit board 227, the impedance on the common-mode current transmission path can be increased, that is, the impedance of the differential signal line 50 can be increased, thereby effectively suppressing the common-mode signal generated by the display panel 25, reducing the common-mode current on the differential signal line, and thus reducing the common-mode signal radiated to the outside of the housing.

[0135] Optional, see reference Figure 12 The light valve circuit board 227 is provided with a first common-mode inductor 303, which is connected in series between the display panel 25 and the light valve circuit board 227 through the differential signal line 50. Alternatively, refer to... Figure 13 The display panel may include a second circuit board 201, on which a light valve driving assembly 202 and a second common-mode inductor 203 may be disposed. The second common-mode inductor 203 is connected in series between the display panel 25 and the light valve circuit board 227 through the differential signal line 50. Alternatively, the light valve circuit board 227 may have a first common-mode inductor 303 disposed thereon, and the second circuit board 201 may have a second common-mode inductor 203 disposed thereon.

[0136] refer to Figure 5 and Figure 6, the distance m1 between the display board 25 and the light valve circuit board 227 can be determined according to the communication rate between the light valve driving component and the light valve in the display board. Optionally, the distance m1 between the display board 25 and the light valve circuit board 227 is the distance between the light valve circuit board 227 and the second circuit board.

[0137] Optionally, the communication rate between the light valve driving component 202 and the light valve 223 is less than or equal to 1.6 gigabits per second (Gbts), and the distance between the display board 25 and the light valve circuit board 227 is less than or equal to 254 millimeters (mm), that is, the distance between the light valve circuit board 227 and the second circuit board 201 is less than or equal to 254 mm. This can ensure good quality of the differential signal received by the light valve 223.

[0138] In the embodiment of the present application, the projection system can be an ultra-short throw projection system. Refer to Figure 14 , D is the distance between the light-emitting side of the lens assembly 23 and the screen 31.

[0139] In the embodiment of the present application, refer to Figure 3 , the distance D0 between the light valve circuit board 227 and the display board 25 in the direction of the optical axis X2 is less than the distance threshold, and the distance threshold is equal to the first difference between the first distance D and the second distance D1.

[0140] Among them, the first distance D is the distance between the light-emitting side of the lens assembly 23 and the screen 31. Refer to Figure 3 , the second distance D1 is the dimension between the second mirror 234 and the light valve circuit board 227 in the direction of the optical axis X2. That is, D0 < D - D1.

[0141] For example, if D = 215 mm and D1 = 197.5 mm, since 215 - 197.5 = 17.5, then D0 < 17.5 mm.

[0142] Alternatively, the distance threshold is equal to the difference between the first difference and the second difference, and the second difference is the difference between the thickness w of the housing of the projection system and the safety distance s. That is, D0 < D - D1 - w - s. The safety distance s is the safety distance that needs to be maintained between the display board and the housing.

[0143] For example, if D = 215 mm, D1 = 197.5 mm, w = 3 mm, and s = 2 mm, since 215 - 197.5 - 3 - 2 = 12.5, then D0 < 12.5 mm.

[0144] In the embodiment of the present application, refer to Figure 15The display panel 25 may further include multiple pairs of first traces 204 and first sockets 205 located on the second circuit board 201. Each pair of first traces 204 includes two first traces 204. One end of each pair of first traces 204 is connected to the light valve drive assembly 202, and the other end is connected to the first socket 205. The two first traces 204 in each pair of first traces 204 have the same spacing, length, and width, and adjacent pairs of first traces 204 have the same spacing, length, and width. The spacing between any first trace 204 and other traces is at least three times the linewidth of the first trace 204.

[0145] The light valve circuit board 227 may further include multiple pairs of second traces 304, second sockets 305, and third sockets 306 located on the light valve circuit board 227. Each pair of second traces 304 includes two second traces 304. One end of each pair of second traces 304 is connected to the second socket 305, and the other end is connected to the third socket 306, which is connected to the light valve 223. The two second traces 304 included in each pair of second traces 304 have the same spacing, length, and width, and adjacent pairs of second traces 304 have the same spacing, length, and width. The spacing between any second trace 304 and other traces is at least three times the linewidth of the second trace 304. In the embodiments of this application, both the first trace and the second trace are LDVS traces.

[0146] The aforementioned differential trace 50 may also include multiple pairs of differential signal lines 50, with each pair comprising two differential signal lines 50. One end of each pair of differential signal lines 50 is connected to the first socket 205, and the other end is connected to the second socket 305, thereby connecting the display panel 25 and the light valve circuit board 227. Adjacent pairs of differential signal lines 50 have the same length and the same cross-sectional area. Each pair of differential signal lines 50 comprises two differential signal lines of the same length and the same cross-sectional area. The spacing between the two differential signal lines 50 is less than half the spacing between the pair of differential signal lines 50 and the shielding layer 70. The differential-mode impedance of the two differential signal lines 50 is within the impedance range of [99.9, 100.1].

[0147] refer to Figure 15The common-mode current transmitted by the optical valve drive assembly 202 flows through the first trace 204, the differential signal line 50, and the second trace 304. Therefore, the common-mode signal corresponding to this common-mode current is transmitted through the first trace 204, the differential signal line 50, and the second trace 304. The arrangement of the first trace, the differential signal line, and the second trace effectively reduces the common-mode current, thereby reducing the common-mode signal and consequently reducing the common-mode signal radiated to the outside of the housing. Furthermore, by wrapping a shielding layer around the differential signal line, the common-mode signal can be conducted to the base plate 60 and then to ground 01, further reducing the common-mode signal radiated to the outside of the housing.

[0148] In this embodiment, the differential-mode impedance of each pair of first traces 204 and each pair of second traces 304 is within an impedance range of [99.9, 100.1]. Each pair of first traces and each pair of second traces can be referred to as a microstrip differential line. Taking the first trace 204 as an example, refer to... Figure 16 The second circuit board 201 may include an insulating layer 206 and a conductive layer 207. The first trace 204 is located between the insulating layer 206 and the conductive layer 207, and the conductive layer 207 may be solder mask. The differential mode impedance Z1 of each pair of first traces satisfies: Z1 = 2 × Z2 × (1 - k), where Z2 is the characteristic impedance of a single microstrip line, i.e., the characteristic impedance of one first trace 204, and k is the coupling coefficient of each pair of first traces.

[0149] in, Should

[0150] refer to Figure 16 S1 is the spacing between the two first traces 204 included in each pair of first traces 204, W1 is the width of the conductive layer 207 covering a first trace 204 on the side closer to the insulating layer 206, Er1 is the dielectric constant of the material of the insulating layer 206, H1 is the thickness of the insulating layer 206, W2 is the width of the conductive layer 207 covering a first trace 204 on the side away from the insulating layer 206, and T1 is the thickness of a first trace 204.

[0151] Assuming S1 = 7.5, K ≈ 0.097, H1 = 4.5, Er1 = 4.5, W1 = 5.5, W2 = 4.5, the Therefore, Z1 = 99.19Ω ≈ 100Ω.

[0152] The common-mode impedance of each pair of first traces 204 is an approximation of the parallel characteristic impedances of the two first traces. If this common-mode impedance Z3 satisfies: N represents the degree of coupling between the shielding layer and the first trace 204.

[0153] Assuming N≈1.14 and Z²≈54.92, then...

[0154] If the differential signal line 50 is approximated as a monopole antenna, then the radiated electric field intensity E of the common-mode current flowing through the differential signal line 50 satisfies: Where: I is the common-mode current flowing through the differential signal line 50, in amperes (A). f represents the sinusoidal frequency of the common-mode current component, in hertz (Hz). L is the length of the differential signal line 50, in meters (m). R represents the distance between the test equipment and the differential signal line 50, in meters (m).

[0155] For example, if the common-mode current is 5 × 10 -3 Given A, L = 1m, R = 3m, f = 100MHz, then The electromagnetic interference test of the projection system is unqualified because the value of 2000 μV / m is greater than the quasi-peak threshold of 40 μV / m.

[0156] In this embodiment, the radiated electric field intensity E of the common-mode current can be reduced by decreasing the length of the differential signal line 50, thereby ensuring that the electromagnetic interference test of the projection system is qualified.

[0157] In scenarios where the distance between the display panel 25 and the light valve circuit board 227 is less than or equal to 254 mm, a shielding layer is wound around the differential signal line 50, a magnetic ring 80 is sleeved on the shielding layer 70, or the projection system includes a common mode inductor, and the differential mode impedance of the differential signal line, the first trace, and the second trace are all within the impedance range, the low-frequency radiated interference field strength of the projection system in the far field is tested by the testing equipment. Figure 17 This is a schematic diagram illustrating the results of a low-frequency radiated disturbance field strength test on a projection system, as provided in an embodiment of this application. Figure 17 As shown in the diagram, the horizontal axis represents the test frequency of the test equipment, i.e., the operating frequency of the antenna in the test equipment, and its unit is megahertz (MHz). The test frequency range is 30MHz to 1000MHz. The vertical axis represents the quasi-peak value of the electromagnetic signal, and its unit is μV / m.

[0158] The first curve Y1 in the result diagram is the quasi-peak value curve of the electromagnetic signal radiated by the projection system within the test frequency range of 30MHz to 1000MHz. The larger the quasi-peak value of the electromagnetic signal of the projection system, the stronger the electromagnetic signal radiated by the projection system. This electromagnetic signal includes the aforementioned common-mode signal. The second curve Y2 in the result diagram is the quasi-peak value threshold curve of the electromagnetic signal that meets the civilian-grade CISPR22 Class B low-frequency radiated disturbance field strength test within the test frequency range of 30MHz to 1000MHz.

[0159] If any quasi-peak value in the first curve Y1 is above the second curve Y2, it can be determined that the projection system radiates a large amount of electromagnetic signal, which cannot meet the usage requirements. If the first curve Y1 is below the second curve Y2, it can be determined that the projection system radiates a small amount of electromagnetic signal, which meets the usage requirements.

[0160] from Figure 17 It can be seen that within the test frequency range of 30MHz to 1000MHz, the first curve Y1 is located below the second curve Y2, meaning that at any test frequency, the quasi-peak value of the electromagnetic signal radiated by the projection system is less than the corresponding quasi-peak value threshold. Therefore, it can be concluded that the projection system has passed the civilian-grade CISPR22 Class B low-frequency radiated field strength interference test and meets the usage requirements.

[0161] Table 1 shows the debugging parameters of the test equipment, the quasi-peak value of the electromagnetic signal radiated by the projection system, the quasi-peak value threshold of the electromagnetic signal, and the difference between the quasi-peak value threshold and the quasi-peak value during the testing process of the projection system. These debugging parameters may include the test frequency, test duration, height of the test equipment above the ground, polarity, and angle of the antenna in the test equipment. The polarity is H, indicating that the antenna of the test equipment is not perpendicular to the projection system. The unit of test duration is ms, and the unit of bandwidth is kilohertz (kHz), with the unit being centimeters (cm).

[0162] Table 1 shows that if the test frequency of the test equipment is 152.1790MHz, the quasi-peak value of the electromagnetic signal radiated by the projection system is 32.81, and the quasi-peak value threshold is 40. Since the quasi-peak value of 32.81 is less than the quasi-peak value threshold of 40, it can be determined that the electromagnetic signal radiated by the projection system is relatively small when the test frequency of the test equipment is 152.1790MHz.

[0163] Table 1

[0164]

[0165] In the above scenario, Figure 18 This is an eye diagram of a light valve receiving a differential signal transmitted by a light valve driving component, as provided in an embodiment of this application. Figure 18 As shown, the horizontal axis of the eye diagram represents time in picoseconds (ps), and the vertical axis represents the voltage of the differential signal received by the light valve 223 in millivolts (mV).

[0166] from Figure 18It can be seen that the voltage of the differential signal received by the light valve 223 is between the first threshold and the second threshold, and the difference between the maximum voltage of the differential signal and the first threshold is relatively large, as is the difference between the minimum voltage of the differential signal and the second threshold. The first threshold is 400mV, and the second threshold is -400mV. Simultaneously, the voltages at the intersection points P1 and P2 in the differential signal are both small, indicating that the jitter of the differential signal is small, meaning the quality of the differential signal is good, and the possibility of bit errors in the differential signal is low. In summary, it can be seen that when the distance between the display panel 25 and the light valve circuit board 227 is less than or equal to 254mm, the quality of the differential signal received by the light valve is good.

[0167] In the embodiments of this application, reference is made to Figure 19 The projection system may also include a heat sink 93 and a conduit 94, one end of which is connected to the heat sink 93 and the other end of which is connected to a support plate at the location of the light source 101. The heat sink 93 dissipates heat from the light source assembly through the conduit 94.

[0168] refer to Figure 19 The projection system may also include a power board 95 located on one side of the lens assembly 23.

[0169] Furthermore, in related technologies, if the projection ratio of the projection system is reduced, the total length of the lens assembly needs to be increased in order to ensure the display effect of the image. However, increasing the total length of the lens assembly will lead to an increase in the projection ratio of the projection system, and the two cannot be balanced.

[0170] In this embodiment, since the optical axes of the first and second lens groups in the lens assembly of the projection system do not intersect, some optical lenses in the lens assembly are arranged along the optical axis of the second lens group, while the remaining optical lenses are arranged along the optical axis of the first lens group. This effectively reduces the number of optical lenses arranged along the optical axis of the second lens group, thereby shortening the distance between the light-emitting side of the second lens group and the projection screen, and reducing the throw ratio of the projection system. This arrangement is applicable to ultra-short-throw projection systems. Furthermore, this arrangement can reduce the throw ratio without increasing the overall length of the lens assembly, ensuring a balance between the two.

[0171] In summary, this application provides a projection system in which the light valve circuit board and lens assembly are arranged parallel to the projection screen, and the surface of the light valve circuit board is perpendicular to the projection screen, while the surface of the display panel is parallel to the projection screen. Therefore, this arrangement effectively reduces the number of optical lenses arranged in the lens assembly perpendicular to the projection screen, thereby shortening the distance between the light-emitting side of the lens assembly and the projection screen, and reducing the throw ratio of the projection system. This arrangement is applicable to ultra-short-throw projection systems.

[0172] In this application, the term "at least one of A and B" merely describes the relationship between related objects, indicating that three relationships can exist. For example, "at least one of A and B" can represent: A existing alone, A and B existing simultaneously, and B existing alone. Similarly, "at least one of A, B, and C" indicates that seven relationships can exist, representing: A existing alone, B existing alone, C existing alone, A and B existing simultaneously, A and C existing simultaneously, C and B existing simultaneously, and A, B, and C existing simultaneously. Likewise, "at least one of A, B, C, and D" indicates that fifteen relationships can exist, representing: A existing alone, B existing alone, C existing alone, D existing alone, A and B existing simultaneously, A and C existing simultaneously, A and D existing simultaneously, C and B existing simultaneously, D and B existing simultaneously, C and D existing simultaneously, A, B, and C existing simultaneously, A, B, and D existing simultaneously, A, C, and D existing simultaneously, and A, B, C, and D existing simultaneously.

[0173] In this application, the terms "first," "second," "third," ... "thirteenth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.

[0174] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A projection system, characterized in that, The projection system includes a light source assembly, an illumination assembly, a lens assembly, and a screen arranged sequentially along the optical path. The lighting assembly includes a light valve, and the light beam emitted by the light source assembly is reflected to the lens assembly after passing through the light valve; The lens assembly includes a first lens group, a first reflector, a second lens group, and a second reflector. The first lens group is used to receive the light beam emitted by the illumination assembly and guide the light beam to the first reflector. The second lens group is used to receive the light beam reflected by the first reflector and guide the light beam to the second reflector. The second reflector is used to guide the light beam to the screen. The maximum distance between the first lens group and the second lens group is less than the sum of the lengths of the first lens group and the second lens group. The optical axis of the second mirror group is perpendicular to the screen, while the optical axis of the first mirror group is not parallel to the optical axis of the second mirror group; the second reflector is located on the side of the second mirror group that is away from the screen.

2. The projection system according to claim 1, characterized in that, The optical axis of the first mirror group is perpendicular to the optical axis of the second mirror group.

3. The projection system according to claim 1, characterized in that, The lighting assembly also includes a third reflector, a light-diffusing device, a prism unit, a first lens unit, and a second lens unit; The light-diffusing device is used to uniformly distribute the light beam emitted by the light source assembly and direct the light beam toward the first lens unit. The first lens unit is used to shape the received light beam and direct the light beam toward the third reflecting mirror; The third reflecting mirror is used to reflect the received light beam toward the second lens unit; The second lens unit is used to guide the received light beam to the prism unit after ensuring that the received light beam meets the aperture coefficient of the lens assembly; The prism unit is used to guide the light beam received from the second lens unit to the light valve and to export the light beam reflected by the light valve to the illumination assembly.

4. The projection system according to claim 3, characterized in that, The first plane defined by the straight line where the optical axis of the lighting component lies before being reflected by the light valve and the straight line where the optical axis of the lighting component lies after being reflected by the light valve is not coplanar with the second plane defined by the optical axes of the first lens group and the second lens group.

5. The projection system according to claim 4, characterized in that, The first plane is perpendicular to the second plane.

6. The projection system according to any one of claims 1-5, characterized in that, The lighting assembly includes a light valve circuit board electrically connected to the light valve, and the projection system includes a display panel electrically connected to the light valve circuit board.

7. The projection system according to claim 6, characterized in that, The display panel is electrically connected to the light valve circuit board via a straight cable.

8. The projection system according to claim 7, characterized in that, The display panel is parallel to the screen and perpendicular to the light valve.

9. The projection system according to claim 8, characterized in that, The display panel is located on the side of the lens assembly closer to the screen; The light valve circuit board and the lens assembly are arranged along a first direction, which is parallel to the screen. The light valve is used to flip under the drive of the light valve control signal and transmit the light beam to the lens assembly.

10. The projection system according to claim 9, characterized in that, The projection system also includes a base plate, and the straight cable includes differential signal lines; the display panel, light valve circuit board and lens assembly are all located on the base plate, and the differential signal lines are in contact with the base plate.

11. The projection system according to claim 10, characterized in that, The projection system also includes: a shielding layer; The shielding layer is wrapped around the outside of the differential signal line, and the shielding layer is grounded.

12. The projection system according to claim 11, characterized in that, The projection system further includes a magnetic ring, which is sleeved on the outside of the shielding layer, and the length of the magnetic ring is less than the length of the shielding layer.

13. The projection system according to claim 10, characterized in that, The projection system also includes: a common-mode inductor; The common-mode inductor is connected in series between the display panel and the light valve circuit board via the differential signal line.

14. The projection system according to any one of claims 9 to 13, characterized in that, The distance between the display panel and the light valve circuit board is determined based on the communication rate between the light valve driving component in the display panel and the light valve.

15. The projection system according to claim 14, characterized in that, The communication rate between the light valve drive assembly and the light valve is less than or equal to 1.6 gigabits per second, and the distance between the display panel and the light valve circuit board is less than or equal to 254 millimeters.

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