Projection system

Abstract

The utility model discloses a projection system which comprises a projection light source, an illumination light path, a display element and a lens. The illumination light path comprises a plurality of lenses and a light beam modulation element, at least one lens is a first lens, and the first lens is obliquely arranged relative to the optical axis of the projection light source. The first lens is obliquely arranged so that the projection light beam can rotate towards the direction of the display element to a certain extent, then the first lens and the light beam adjusting element which are obliquely arranged are used for shaping the emergent light of the projection light source, the projection light beam is turned to the display element, and it is ensured that the projection light beam can be effectively reflected and uniformly covers the display element. Therefore, a total reflection prism is omitted in the projection system, the light path structure is simpler and more compact, the overall size of the projection system is reduced, and the problem of cost increase caused by the total reflection prism can be solved.

Description

Technical Field

[0001] This application relates to the field of projection technology, and more particularly to a projection system. Background Technology

[0002] Projection display is a technology that uses planar image information to control a light source, and utilizes an optical system and projection space to magnify and display the image on a projection screen. With the development of projection display technology, projection displays are gradually being applied to business activities, conferences and exhibitions, scientific education, military command, traffic management, centralized monitoring, and advertising and entertainment. Its advantages, such as large display size and clear display, are also suitable for the requirements of large-screen displays.

[0003] Current projection systems typically include a projection light source and a display element. The projection beam emitted from the light source needs to be shaped before it illuminates the display element. The display element modulates the incident projection beam to generate an image beam, which is then imaged by a lens. To separate the illumination beam illuminating the display element from the image beam exiting the lens, a total internal reflection prism is usually placed in the optical path. The total internal reflection prism reflects the illumination beam back to the display element, and then guides the light exiting the display element to the lens. The total internal reflection prism needs to be designed individually for different projection system applications, which not only makes the optical path of the projection system complex and the overall size larger, but also increases the production cost of the projection system. Utility Model Content

[0004] This application provides a projection system, including:

[0005] Projection light source, used to emit projection beams;

[0006] An illumination optical path is located on the light-emitting side of the projection light source; the illumination optical path includes:

[0007] Multiple lenses are located on the light-emitting side of the projection light source; the multiple lenses include at least one first lens, which is tilted relative to the optical axis of the projection light source;

[0008] A beam adjustment element, located in the optical path of the plurality of lenses, is used to adjust the propagation direction of the beam;

[0009] A display element is located on the light-emitting path of the beam adjustment element, and the display element is used to adjust the incident light to generate an image beam; and

[0010] The lens is located on the light-emitting side of the display element and projects the image beam emitted by the display element.

[0011] In some embodiments of this application, the optical axis of the projection light source does not coincide with the center of the first lens.

[0012] In some embodiments of this application, the vertical distance from the center of the first lens to the optical axis of the projection light source is 0.1 mm to 5 mm.

[0013] In some embodiments of this application, the tilt angle of the optical axis of the first lens relative to the optical axis of the projection light source is 5° to 45°.

[0014] In some embodiments of this application, the plurality of lenses further includes a second lens, which is disposed close to the display element and located between the display element and the lens, wherein the optical axis of the second lens coincides with the optical axis of the lens.

[0015] In some embodiments of this application, the relative positions of the beam adjustment element, the display element, and the second lens satisfy the following:

[0016] D>l1+l2+a;

[0017] l1 = d1 × tanα;

[0018] l2 = d2 × tanβ;

[0019] tanβ=tan∠α-(a+d1×tanα) / f;

[0020] D represents the vertical distance from the edge of the beam adjustment element to the optical axis of the lens; l1 represents the offset in a direction perpendicular to the optical axis of the lens when the first ray emitted from the edge of the display element enters the second lens; l2 represents the offset in a direction perpendicular to the optical axis of the lens when the first ray enters the edge of the beam adjustment element from the second lens; d1 represents the distance between the display element and the second lens along the optical axis of the lens; d2 represents the distance between the second lens and the edge of the beam adjustment element along the optical axis of the lens; α represents the divergence angle of the emitted light from the display element; β represents the divergence angle of the emitted light from the second lens; f represents the focal length of the second lens; a represents the half-width of the display element.

[0021] In some embodiments of this application, the beam adjustment element is a reflector;

[0022] The tilt angle of the reflector relative to the optical axis of the projection light source is 10° to 60°.

[0023] In some embodiments of this application, both the first lens and the second lens are convex lenses.

[0024] In some embodiments of this application, the projection light source includes:

[0025] A light-homing element is used to homogenize the projected beam; the light-homing element is a light guide or a compound eye lens.

[0026] In some embodiments of this application, it further includes:

[0027] An image offset element is located between the display element and the lens; the image offset element is used to offset the image beam emitted from the display element.

[0028] The projection system provided in this application includes: a projection light source, an illumination optical path, a display element, and a lens. The projection beam emitted from the projection light source is shaped by the illumination optical path and then incident on the display element. The display element modulates the incident projection beam to form an image beam, which is then imaged by the lens. The illumination optical path includes multiple lenses and a beam modulation element, wherein at least one lens is a first lens, which is tilted relative to the optical axis of the projection light source. The tilted first lens can rotate the projection beam towards the display element to a certain extent. The tilted first lens and the beam modulation element then shape the emitted light from the projection light source, directing the projection beam towards the display element, ensuring that the projection beam can be effectively reflected and uniformly cover the display element. This eliminates the need for a total internal reflection prism in the projection system, making the optical path structure simpler and more compact, reducing the overall size of the projection system, and also solving the cost increase problem associated with total internal reflection prisms. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the 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.

[0030] Figure 1 This is a schematic diagram of the structure of a projection system in related technologies;

[0031] Figure 2 This is one of the structural schematic diagrams of the projection system provided in the embodiments of this application;

[0032] Figure 3 This is one of the structural schematic diagrams of the projection light source provided in the embodiments of this application;

[0033] Figure 4 This is the second schematic diagram of the structure of the projection light source provided in the embodiments of this application;

[0034] Figure 5 This is a second schematic diagram of the projection system provided in the embodiments of this application;

[0035] Figure 6This is the third schematic diagram of the projection system provided in the embodiments of this application;

[0036] Figure 7 This is a schematic diagram showing the positional relationship of components in a projection system provided in an embodiment of this application;

[0037] Figure 8 Fourth schematic diagram of the projection system provided in the embodiments of this application;

[0038] Figure 9 Fifth schematic diagram of the projection system provided in the embodiments of this application;

[0039] Figure 10 This is the sixth schematic diagram of the projection system provided in the embodiments of this application. Detailed Implementation

[0040] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the application will be further described below in conjunction with the accompanying drawings and embodiments. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the figures denote the same or similar structures, and therefore repeated descriptions of them will be omitted. Terms describing position and direction described in this application are illustrative based on the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this application. The accompanying drawings of this application are for illustrating relative positional relationships only and do not represent actual scale.

[0041] Projection display is a technology that uses planar image information to control a light source, and utilizes an optical system and projection space to magnify and display the image on a projection screen. With the development of projection display technology, projection displays are gradually being applied to business activities, conferences and exhibitions, scientific education, military command, traffic management, centralized monitoring, and advertising and entertainment. Its advantages, such as large display size and clear display, are also suitable for the requirements of large-screen displays.

[0042] Figure 1 This is a schematic diagram of the projection system provided in an embodiment of this application.

[0043] like Figure 1 As shown, the projection system includes: a projection light source 11, an illumination light path 12, a total reflection prism 13, a display element 14, and a lens 15.

[0044] The projection light source 11 emits a projection beam, and the illumination light path 12 is located on the light-emitting side of the projection light source 11. The illumination light path 12 can shape the projection beam so that the projection beam illuminates the display element 14 at a suitable size and angle. The display element 14 can modulate the projection beam to form an image beam, and the image beam is imaged through the lens 15.

[0045] Current projection systems typically include a total internal reflection prism 13, which separates the illumination light path from the imaging light path. The illumination light path refers to the path of the projection beam emitted from the projection light source, which, after homogenization and shaping, illuminates the display element 14. The imaging light path refers to the path of the image beam emitted from the display element 14, which is then imaged by the lens 15. The total internal reflection prism 13 is positioned close to the display element 14 to totally reflect the illumination beam back to the display element, and then guides the image beam emitted from the display element to the lens.

[0046] When applied to different scenarios, the type of projection light source may be different, and the incident direction and angle of the incident light spot required by the display element 14 may be different. As a result, the total internal reflection prism needs to be designed separately according to different application scenarios. This not only makes the optical path of the projection system complex and the overall size larger, but also increases the cost.

[0047] In view of this, this application provides a projection system, such as Figure 2 As shown, it includes: a projection light source 11, an illumination light path 12, a display element 14, and a lens 15.

[0048] The projection light source 11 is used to emit the projection beam. In specific implementations, the projection light source 11 can be a light-emitting diode (LED) or a laser light source.

[0049] Figure 3 This is a schematic diagram of the structure of an LED light source, such as... Figure 3 As shown, an LED light source typically includes: a light-emitting diode package 111 and a collimating lens group 112 located on the light-emitting side of the light-emitting diode package 111.

[0050] The light-emitting diode package 111 refers to the packaged light-emitting diode, including the light-emitting diode chip and the package bracket used to package the light-emitting diode chip. A refractive lens can be set on the package bracket to change the light emission pattern of the light-emitting diode chip.

[0051] The intensity distribution of the light emitted from the LED package 111 is typically a Lambertian distribution with a large divergence angle. Therefore, a collimating lens group 112 is provided on the light-emitting side of the LED package 111 to collimate the emitted light.

[0052] The collimating lens group 112 includes at least one lens for converging the emitted light from the light-emitting diode package 111, thereby reducing the divergence angle of the projection light source. Figure 3 For example, the collimating lens group 112 may include two lenses 1121 and 1122, and both lenses 1121 and 1122 may be convex lenses, which is not limited here.

[0053] Figure 4 This is a schematic diagram of the structure of a laser source, such as... Figure 4 As shown, when a laser light source is used for projection, the laser light source can be a laser that can emit lasers of multiple colors or multiple lasers that emit lasers of different colors.

[0054] When a monochromatic laser is used as the laser source, a wavelength conversion device (such as a phosphor wheel) and a color wheel need to be installed in the projection light source for color conversion. The monochromatic laser, together with the wavelength conversion device and the color wheel, can achieve the purpose of emitting different primary colors of light in sequence. When a laser capable of emitting multiple colors of laser light is used as the laser source, it is necessary to control the laser source to emit different colors of laser light as primary colors in sequence.

[0055] Figure 4 The laser source shown is a laser 113 that can emit three primary colors of laser light, such as a NUMB laser. When a three-color laser is used, a beam combiner assembly 114 needs to be installed on the output side of the laser 113 to combine the three colors of laser light. Laser chips are arranged in the laser 113, and the structure and function of the beam combiner assembly 114 vary depending on the arrangement of the laser chips.

[0056] by Figure 4 For example, laser 113 includes three types of laser chips: a first laser chip r that emits red laser light, a second laser chip g that emits green laser light, and a third laser chip b that emits blue laser light. The first laser chips r are arranged in a row, and the second laser chips g and third laser chips b are arranged in a row. To combine the three laser colors, a light combining assembly 114 may include a first light combining component 1141 and a second light combining component 1142. The first light combining component 1141 is located on the light-emitting side of the second laser chip g and the third laser chip b, and the second light combining component 1142 is located on the light-emitting side of the first laser chip r. The first light combining component 1141 reflects the green laser light emitted from the second laser chip g and the blue laser light emitted from the third laser chip b towards the second light combining component 1142. The second light combining component 1142 transmits the green laser light emitted from the second laser chip g and the blue laser light emitted from the third laser chip b, while simultaneously reflecting the red laser light emitted from the first laser chip r, thereby combining the three laser colors.

[0057] When the arrangement of laser chips in a laser changes, the number, location, and function of the light combining element will also change accordingly, which will not be limited here.

[0058] like Figure 2 As shown, the illumination light path 12 is located on the light-emitting side of the projection light source 11. The illumination light path 12 shapes and homogenizes the emitted light from the projection light source on the one hand, and on the other hand, it can make the emitted light from the projection light source incident on the display element 14 at a suitable angle.

[0059] The illumination path 12 includes multiple lenses, which are used to shape the projection beam emitted from the projection light source, thereby making the size and shape of the incident display element 14 more compatible with the display element 14 and improving the utilization rate of the projection light source.

[0060] The display element 14 is located on the light output path of the illumination light path 12. The display element 14 is used to modulate the incident light to form an image beam.

[0061] In some embodiments, the display element 14 may be a digital micromirror device (DMD), liquid crystal on silicon (LCoS), or liquid crystal display (LCD).

[0062] In this embodiment, a DMD is used as an example. The surface of the DMD includes a number of micro-mirrors, each of which can be individually driven to deflect. By controlling the deflection angle of the DMD, the brightness of the emitted light from the display element 14 is controlled.

[0063] The lens 15 is located on the light-emitting side of the display element 14 and projects the image beam emitted from the display element 14.

[0064] Lens 15 typically includes multiple lenses. The surface shape, number, and focal length of the lenses can be specifically optically designed according to the application scenario and projection ratio of the projection system, and are not limited here.

[0065] like Figure 2As shown, the illumination optical path 12 includes multiple lenses, at least one of which is a first lens 121, which is tilted relative to the optical axis of the projection light source. The illumination optical path 12 also includes a beam adjustment element 123, located within the lens's optical path, used to adjust the beam propagation direction. This embodiment utilizes the tilted first lens 121 and the beam adjustment element 123 to shape the emitted light from the projection light source, directing the projected beam towards the display element 14. This eliminates the need for a total internal reflection prism in the projection system, making the optical path structure simpler and more compact, reducing the overall size of the projection system, and also solving the cost increase problem associated with total internal reflection prisms.

[0066] Specifically, after eliminating the total internal reflection prism, to guide the projection beam to the display element 14, a beam adjustment element 123 is needed to adjust the propagation direction of the projection beam. The beam adjustment element 123 can be a mirror or a reflective film to reflect light across the entire wavelength range. However, if only the beam modulation element 123 is used to adjust the propagation direction of the projection beam, the beam adjustment element needs to be placed completely above the display element 14, which would block the light path from the display element 14 to the lens 15. Therefore, in this embodiment, the first lens 121 is tilted so that the projection beam can rotate to a certain extent towards the display element 14, and then matched with the deflection angle of the beam modulation element 123, thereby ensuring that the projection beam can be effectively reflected and uniformly cover the display element 14.

[0067] like Figure 2 As shown, although the first lens and beam adjustment element are tilted to adjust the direction of the projection beam, the edge region X of the beam modulation element 123 will still be located between the optical path of the display element 14 and the lens 15, which will block the light emitted from the edge of the display element 14, preventing this part of the light from entering the lens 15 for imaging.

[0068] To avoid the edge region of the beam adjustment element blocking light, such as Figure 5 As shown, the edge region X can be cropped. However, cropping the edge region X will prevent the light that was originally reflected through the edge region X from hitting the display element 14, resulting in uneven illumination spots on the display element 14.

[0069] In view of this, such as Figure 6As shown, in this embodiment, the projection light source 11 is moved upwards as a whole so that the optical axis of the projection light source 11 corresponds to the center point of the clipped beam adjustment element 123, so that the beam adjustment element 123 can effectively receive the projection beam. At the same time, the tilt angle of the first lens 121 needs to be further adjusted so that the projection beam can be reflected by the beam modulation element 123 after passing through the first lens 121 and uniformly cover the display element 14.

[0070] In a specific implementation, the tilt angle of the optical axis of the first lens 121 relative to the optical axis of the projection light source 11 can be 5° to 45°; correspondingly, the tilt angle of the beam adjustment element 123 relative to the optical axis of the projection light source 11 is 10° to 60°.

[0071] The tilt angles of the first lens 121 and the beam adjustment element 123 need to be adjusted according to the relative position of the projection light source 11 and the display element 14, as well as the angle at which the projection beam enters the display element 14. The tilt angles of the first lens 121 and the beam adjustment element 123 need to be adjusted together, and no specific tilt angle value is limited here.

[0072] like Figure 6 As shown, after the projection light source 11 is moved upwards as a whole, the optical axis of the projection light source will no longer coincide with the center of the first lens 121. A distance d is generated between the optical axis of the projection light source 11 and the center of the first lens 121, which is typically between 0.1 mm and 5 mm. This distance is the distance that the projection light source 11 moves upwards. The specific distance that the projection light source 11 moves needs to be determined based on the center position after adjustment by the beam adjustment element 123.

[0073] In some embodiments, such as Figure 6 As shown, the illumination optical path 12 further includes a second lens 122, which is disposed close to the display element 14 and located on the light-emitting side of the display element 14. The second lens 122 is a lens shared by the illumination optical path 12 and the lens 15, and the optical axis of the second lens 122 coincides with the optical axis of the lens 15. In the illumination optical path, the second lens 122, together with the first lens 121, plays a role in shaping the projection beam, while in the imaging optical path and other lenses in the lens 15, the image beam is imaged.

[0074] The projection beam emitted from the projection light source 11 is focused by the first lens 121 and then incident on the beam adjustment element 123. It is reflected by the beam adjustment element 123 to the second lens 122, and then focused again by the second lens 122 before entering the display element 14. At this point, the shape of the illumination spot incident on the display element 14 is the same as the shape of the light-receiving surface of the display element 14, and the size of the illumination spot is slightly larger than the effective area of ​​the display element 14. The display element 14 modulates the incident projection beam and then emits an image beam. The image beam passes through the second lens 122 again and then enters other lenses in the lens 15 for imaging, projecting a clear image at a set position.

[0075] In some embodiments, both the first lens 121 and the second lens 122 can be convex lenses, used to converge the projection beam, reduce the divergence angle of the projection beam, and make the size of the light spot projected onto the display element adapt to the effective area of ​​the display element.

[0076] like Figure 7 As shown, to avoid the beam adjustment element blocking the imaging light, the relative positions between the beam adjustment element 123, the display element 14, and the second lens 122 satisfy the following:

[0077] D>l1+l2+a;

[0078] l1 = d1 × tanα;

[0079] l2 = d2 × tanβ;

[0080] tanβ=tan∠α-(a+d1×tanα) / f;

[0081] Where D represents the vertical distance from the edge of the beam adjustment element to the optical axis of the lens; l1 represents the offset in the direction perpendicular to the optical axis of the lens when the first ray emitted from the edge of the display element enters the second lens; l2 represents the offset in the direction perpendicular to the optical axis of the lens when the first ray emitted from the second lens enters the edge of the beam adjustment element; d1 represents the distance between the display element and the second lens along the optical axis of the lens; d2 represents the distance between the edge of the second lens and the beam adjustment element along the optical axis of the lens; α represents the divergence angle of the emitted light from the display element; β represents the divergence angle of the emitted light from the second lens; and f represents the focal length of the second lens.

[0082] Specifically, such as Figure 7 As shown, based on trigonometric relationships, we can obtain:

[0083] l1 = d1 × tanα;

[0084] l2 = d2 × tanβ;

[0085] The first ray emitted from the edge of the display element 14 deflects in the direction perpendicular to the optical axis of the second lens 122 as it propagates: a + d1 × tanα, where a is half the width of the display element.

[0086] Then, the first ray emitted from the edge of the display element 14 will exit further from the second lens 122 towards the edge of the beam adjustment element 123. According to the imaging law of thin lenses, the angle change of the light before and after passing through the thin lens is inversely proportional to the offset, with a proportionality coefficient of 1 / f. Therefore, the divergence angle β of the light beam after passing through the second lens satisfies:

[0087] tanβ=tanα-(a+d1×tanα) / f;

[0088] Therefore, based on the above relationship, the dimensions of l1+l2+a can be calculated, thereby determining the relative positions between the beam adjustment element 123, the display element 14, and the second lens 122.

[0089] In some embodiments, such as Figure 8 and Figure 9 As shown, the projection light source also includes a homogenizing element 16, used to homogenize the projection beam. When the projection light source is moved upward, the homogenizing element 16 also needs to be moved upward.

[0090] In specific implementation, such as Figure 8 As shown, the light-diffusing element 16 can be a light guide; or, as... Figure 9 As shown, the light-diffusing element 16 can also be a compound eye lens.

[0091] like Figure 8 As shown, the light guide is typically made of a highly transparent material, and its cross-section can be rectangular, cylindrical, or hexagonal. The cross-sectional shape of the light guide is usually the same as the shape of the effective area of ​​the display element 14. The inner wall surface of the light guide is polished or coated, and guides the light using total internal reflection or specular reflection. The light undergoes multiple reflections on the inner wall of the guide, and light rays at different angles mix during transmission, reducing spatial and angular non-uniformity. Extending the optical path length makes the energy distribution of the light beam more uniform.

[0092] Light guides are easy to integrate into space-constrained systems, have low requirements for light source collimation, can handle beams with large divergence angles (such as LED light sources), and have mature manufacturing processes and low costs.

[0093] like Figure 9As shown, the compound eye lens consists of two identical microlens arrays, each containing dozens to hundreds of microlenses. The microlenses are typically square or hexagonal, arranged closely in a grid or honeycomb structure. The microlenses in the front and rear microlens arrays correspond one-to-one, forming an integration channel. The front array divides the incident light into multiple sub-beams, each of which is imaged onto the target surface (such as the light-incident surface of display element 14) by the rear array. The intensity distributions of different sub-beams are superimposed and statistically averaged to achieve homogenization. By adjusting the focal length and spacing of the microlenses, the divergence angle and uniformity of the output light field can be controlled.

[0094] Compound eye lenses eliminate local light intensity differences through the integration effect, making them suitable for scenarios requiring high precision and uniformity. By designing microlens parameters, the shape, size, and uniformity of the light spot can be optimized. Compound eye lenses are insensitive to the spatial distribution and coherence of the light source and can handle various light sources such as lasers and LEDs.

[0095] Light guides are suitable for scenarios where size and cost are critical and the light source divergence angle is large, while compound eye lenses are more suitable for scenarios requiring high uniformity and good light source collimation. In practical applications, the homogenizing element 16 can be selected according to the specific application scenario, and no limitation is made here.

[0096] In some embodiments, such as Figure 10 As shown, the projection system also includes an image shifting element 17, which is located between the display element 14 and the lens 15, specifically between the display element 14 and the second lens 122. The image shifting element 17 is used to shift the image beam emitted from the display element 14.

[0097] In practical implementation, the image polarization element 17 can be made of flat glass. When the flat glass is tilted at a certain angle, the tilt of its surface causes the refraction direction of the light after passing through to change, thereby shifting the position of the emitted beam of the display element 14. Then, by high-frequency periodic vibration, the emitted position of the light can be periodically shifted. At the same time, by superimposing multiple frames of images, the resolution of the displayed image can be improved.

[0098] The projection system provided in this application includes a projection light source, an illumination optical path, a display element, and a lens. The projection beam emitted from the projection light source is shaped by the illumination optical path and then incident on the display element. The display element modulates the incident projection beam to form an image beam, which is then imaged by the lens. The illumination optical path includes multiple lenses and a beam modulation element, wherein at least one lens is a first lens, which is tilted relative to the optical axis of the projection light source. The tilted first lens can rotate the projection beam towards the display element to a certain extent. The tilted first lens and the beam modulation element then shape the emitted light from the projection light source, directing the projection beam towards the display element, ensuring that the projection beam can be effectively reflected and uniformly cover the display element. This eliminates the need for a total internal reflection prism in the projection system, making the optical path structure simpler and more compact, reducing the overall size of the projection system, and also solving the cost increase problem associated with total internal reflection prisms.

[0099] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0100] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A projection system, characterized in that, include: Projection light source, used to emit projection beams; The illumination light path is located on the light-emitting side of the projection light source; The illumination optical path includes: Multiple lenses are located on the light-emitting side of the projection light source; the multiple lenses include at least one first lens, which is tilted relative to the optical axis of the projection light source; A beam adjustment element, located in the optical path of the plurality of lenses, is used to adjust the propagation direction of the beam; A display element is located on the light-emitting path of the beam adjustment element, and the display element is used to adjust the incident light to generate an image beam; and The lens is located on the light-emitting side of the display element and projects the image beam emitted by the display element.

2. The projection system as described in claim 1, characterized in that, The optical axis of the projection light source does not coincide with the center of the first lens.

3. The projection system as described in claim 2, characterized in that, The vertical distance from the center of the first lens to the optical axis of the projection light source is 0.1 mm to 5 mm.

4. The projection system as described in claim 1, characterized in that, The optical axis of the first lens is tilted at an angle of 5° to 45° relative to the optical axis of the projection light source.

5. The projection system as described in claim 1, characterized in that, The plurality of lenses further includes a second lens, which is disposed close to the display element and located between the display element and the lens, wherein the optical axis of the second lens coincides with the optical axis of the lens.

6. The projection system as described in claim 5, characterized in that, The relative positions of the beam adjustment element, the display element, and the second lens satisfy the following: D>l1+l2+a; l1 = d1 × tanα; l2 = d2 × tanβ; tanβ=tan∠α-(a+d1×tanα) / f; Wherein, D represents the vertical distance from the edge of the beam adjustment element to the optical axis of the lens; l1 represents the offset in the direction perpendicular to the optical axis of the lens when the first ray emitted from the edge of the display element enters the second lens; l2 represents the offset in the direction perpendicular to the optical axis of the lens when the first ray enters the edge of the beam adjustment element from the second lens; d1 represents the distance between the display element and the second lens along the optical axis of the lens; d2 represents the distance between the second lens and the edge of the beam adjustment element along the optical axis of the lens; α represents the divergence angle of the emitted light from the display element; β represents the divergence angle of the emitted light from the second lens; f represents the focal length of the second lens; and a represents the half-width of the display element.

7. The projection system as claimed in claim 1, characterized in that, The beam adjustment element is a reflector; The tilt angle of the reflector relative to the optical axis of the projection light source is 10° to 60°.

8. The projection system as described in claim 5, characterized in that, Both the first lens and the second lens are convex lenses.

9. The projection system as described in any one of claims 1 to 7, characterized in that, The projection light source includes: A light-homing element is used to homogenize the projected beam; the light-homing element is a light guide or a compound eye lens.

10. The projection system according to any one of claims 1 to 7, characterized in that, Also includes: An image offset element is located between the display element and the lens; the image offset element is used to offset the image beam emitted from the display element.

Images