Projection light machine and near-eye display device

Abstract

The embodiments of the present application provide a projection optical engine and a near-eye display device. The projection optical engine includes a display panel and a projection lens. The display panel is configured to be movable relative to the projection lens in a direction perpendicular to the optical axis of the projection lens so as to deflect the light emitted by the projection lens. The projection lens includes a fifth lens with positive optical power, a fourth lens with positive optical power, a third lens with negative optical power, a second lens with positive optical power, and a first lens with negative optical power, which are coaxial and sequentially arranged along the light transmission direction. The deflection angle b of the main light ray emitted by the projection lens satisfies the following condition: b=FOV*D / h; wherein D is the offset distance of the center of the display panel relative to the optical axis of the projection lens, FOV is the field of view of the projection lens, and h is the imaging height of the display panel.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of wearable technology, and more specifically, to a projection optical machine and a near-eye display device. Background Art

[0002] Currently, most AR devices have limited display methods, with their viewing angles typically fixed within a preset range. Even if some devices support tilt adjustment, this functionality relies primarily on software algorithm optimization and modulation, rather than direct hardware adjustments.

[0003] In addition, in terms of optical machine design, existing solutions generally adopt a 0° design with a fixed output light direction. After matching this design with the optical waveguide component, the image ultimately projected to the human eye is also limited to a fixed viewing angle range, making it difficult to flexibly adjust according to user needs or environmental changes.

[0004] In view of this, it is necessary to provide a new technical solution to solve the above technical problems. Summary of the Invention

[0005] The purpose of this application is to provide a new technical solution for projection optical machine and near-eye display device.

[0006] In a first aspect, embodiments of the present application provide a projection optical engine. The projection optical engine includes a display panel and a projection lens, wherein the display panel is configured to be movable relative to the projection lens in a direction perpendicular to the optical axis of the projection lens so as to deflect light emitted from the projection lens;

[0007] The projection lens comprises a fifth lens with positive optical power, a fourth lens with positive optical power, a third lens with negative optical power, a second lens with positive optical power, and a first lens with negative optical power, which are coaxially arranged in sequence along the light transmission direction;

[0008] The deflection angle b of the chief ray of the light emitted by the projection lens satisfies the following conditions:

[0009] b=FOV*D / h;

[0010] Wherein, D is the offset distance of the center of the display panel relative to the optical axis of the projection lens, FOV is the field of view of the projection lens, and h is the imaging height of the display panel.

[0011] Optionally, the first lens, the second lens, the third lens, the fourth lens and the fifth lens satisfy the following condition: 1.5<(f1+f2+f3) / (f4+f5)<1.6;

[0012] Among them, f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, and f5 is the effective focal length of the fifth lens.

[0013] Optionally, the first lens, the second lens, the third lens, the fourth lens and the fifth lens satisfy the following relationship:

[0014] 29mm<f1<37mm;

[0015] 8mm<f2<10mm;

[0016] -5mm<f3<-4mm;

[0017] 8mm<f4<19mm;

[0018] 7mm<f5<14mm.

[0019] Optionally, the first lens, the second lens, the third lens, the fourth lens and the fifth lens satisfy the following relationship:

[0020] 4< f 1 / f <5.0;

[0021] 1.1< f 2 / f <1.3;

[0022] -0.7< f 3 / f <-0.6;

[0023] 1.2< f 4 / f <2.5;

[0024] 1< f 5 / f <2;

[0025] Wherein, f is the total effective focal length of the projection lens.

[0026] Optionally, the first lens, the second lens, the third lens, the fourth lens and the fifth lens satisfy the following relationship:

[0027] 2.6<(f1+f2+f3) / L<3.1;

[0028] 1.6<(f4+f5) / L<2.0;

[0029] Wherein, L is the total optical length of the projection optical machine.

[0030] Optionally, the air gap between the first lens and the second lens is A1, the air gap between the third lens and the fourth lens is A2, the air gap between the third lens and the fourth lens is A3, the air gap between the fourth lens and the fifth lens is A4, and the air gap between the fifth lens and the prism assembly in the projection optical machine is A5;

[0031] Among them, 1.0<(A1+A2) / (A3+A4+A5)<1.1.

[0032] Optionally, the projection light engine satisfies:

[0033] 0.1<(A1+A2) / L<0.2;

[0034] 0.1<(A3+A4+A5) / L<0.2;

[0035] Wherein, L is the total optical length of the projection optical machine

[0036] Optionally, the projection light engine satisfies:

[0037] 0.45<h / L<0.60, wherein L is the total optical length of the projection optical machine.

[0038] In a second aspect, embodiments of the present application further provide a near-eye display device. The near-eye display device includes a projection optical engine and a waveguide device as described above, wherein the projection optical engine is located in an incoupling region of the waveguide device, and the outcoupling region of the waveguide device is used to couple out image light that matches the location of the display panel.

[0039] Optionally, a diaphragm is provided on the side of the first lens of the projection optical engine facing away from the second lens, and an aperture size of the diaphragm satisfies: 2.5 mm < pupil < 4.5 mm.

[0040] One of the technical effects of this application is:

[0041] An embodiment of the present application provides a projection engine that, based on a positionally adjustable display panel, deflects light emitted from a projection lens. In specific applications, the deflection angle of the image emitted by a near-eye display device can be adjusted based on the offset distance of the display panel relative to the projection lens. Furthermore, the present application eliminates the need for overall deflection of the projection engine to achieve image angle deflection, reducing the space occupied by the projection engine and thus facilitating the miniaturization of the projection engine and near-eye display device.

[0042] Other features and advantages of the present specification will become apparent from the following detailed description of exemplary embodiments of the present specification with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.

[0044] Figure 1-Figure 3 Shown is a structural diagram of a near-eye display device provided in an embodiment of the present application.

[0045] Figure 4 The optical structure of the projection lens provided in the embodiment of the present application is shown as follows Figure 1 .

[0046] Figure 5 Shown Figure 4 MTF diagram of the projection lens.

[0047] Figure 6 Shown Figure 4 Through-focus MTF diagram of the projection lens.

[0048] Figure 7 Shown Figure 4 The optical path of the projection lens after the display panel moves in the corresponding projection optical machine Figure 1 .

[0049] Figure 8 Shown Figure 4 The optical path of the projection lens after the display panel moves in the corresponding projection optical machine Figure 2 .

[0050] Figure 9 The optical structure of the projection lens provided in the embodiment of the present application is shown as follows Figure 2 .

[0051] Figure 10 Shown Figure 9 The corresponding MTF diagram of the projection optical machine.

[0052] Description of reference numerals:

[0053] 1. Display panel; 2. Prism assembly; 3. Projection lens; 31. First lens; 32. Second lens; 33. Third lens; 34. Fourth lens; 35. Fifth lens;

[0054] 4. Waveguide device; 41. Incoupling region; 42. Outcoupling region. DETAILED DESCRIPTION

[0055] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application.

[0056] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0057] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

[0058] In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0059] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0060] The present application provides an optical projection engine. For example, the optical projection engine can be an AR engine, which can be a Micro LED engine, an LCoS engine, or a DLP engine. The optical projection engine works in conjunction with a waveguide device 4 to provide a near-eye display device. For example, the near-eye display device can be an AR device, which can be AR glasses.

[0061] Reference Figure 1-Figure 3 as well as Figure 4 、 Figure 7-Figure 9 The projection optical machine includes: a display panel 1 and a projection lens 3, wherein the display panel 1 is configured to be movable relative to the projection lens 3 in a direction perpendicular to the optical axis of the projection lens 3 so as to deflect the light emitted by the projection lens 3;

[0062] The projection lens 3 includes a fifth lens 35 with positive optical power, a fourth lens 34 with positive optical power, a third lens 33 with negative optical power, a second lens 32 with positive optical power, and a first lens 31 with negative optical power, which are coaxially arranged in sequence along the light transmission direction.

[0063] The deflection angle b of the chief ray of the light emitted by the projection lens 3 satisfies the following conditions:

[0064] b=FOV*D / h;

[0065] Wherein, D is the offset distance of the center of the display panel 1 relative to the optical axis of the projection lens 3 , FOV is the field of view of the projection lens 3 , and h is the imaging height of the display panel 1 .

[0066] In the embodiment of the present application, the projection optical engine is mainly composed of a display panel 1 and a projection lens 3. Among them, the projection lens 3 is located on the light-emitting side of the display panel 1 to ensure that light can be smoothly and efficiently transmitted from the display panel 1 to the projection lens 3 to form a clear projected image.

[0067] In addition, to further optimize the optical path design and enhance the projection effect, a prism assembly 2, such as an Xcube prism, is added to the optical path between the display panel 1 and the projection lens 3. This not only helps to effectively refract and converge light, but also corrects aberrations to a certain extent, thereby ensuring that the final projected image has higher clarity and color reproduction.

[0068] In the embodiment of the present application, the display panel 1 is configured to be movable relative to the projection lens 3 along a direction perpendicular to the optical axis of the projection lens 3 , so as to deflect the light emitted by the projection lens 3 .

[0069] For example, the display panel 1 is moved by a mechanical structure or a drive system to ensure the accuracy and stability of the offset. Those skilled in the art can select different mechanical structures or drive systems to move the display panel 1 according to actual application scenarios and requirements, and the embodiments of this application will not be repeated here.

[0070] When the display panel 1 moves relative to the projection lens 3 in a direction perpendicular to the optical axis, the incident angle of light emitted from different positions of the display panel 1 relative to the projection lens 3 changes. This change in the incident angle causes the refraction angle of the light to change when passing through the projection lens 3, thereby changing the propagation direction of the light.

[0071] Because each point on the display panel 1 corresponds to a pixel in the projected image, the light emitted by these pixels deflects accordingly when the display panel 1 moves. This deflection is holistic; that is, the entire projected image deflects as the display panel 1 moves, thereby achieving deflection control of the light emitted by the projection lens 3. Therefore, in the embodiments of the present application, by adjusting the position of the display panel 1, the position and angle of the projected image can be flexibly controlled to adapt to different projection scenarios and requirements.

[0072] In a specific application scenario, a projection engine is used in a near-eye display device, where the display image can be deflected. For example, by adjusting the position of the display panel 1, the position of the virtual image in the wearer's eye box can be dynamically adjusted, so that the virtual image is synchronized with the wearer's line of sight, thereby improving the user experience of wearing the near-eye display device.

[0073] In another specific application scenario, by adjusting the position of the display panel 1 relative to the projection lens 3, the image output by the projection lens 3 can be deflected, and the position of the image output by the projection optical machine can be adjusted.

[0074] In the embodiment of the present application, the display panel 1 is configured to be movable relative to the projection lens 3 in a direction perpendicular to the optical axis of the projection lens 3, which can be understood as the following three situations:

[0075] In one example, under the action of an external driving force, the display panel 1 can move relative to the projection lens 3 in a first direction, where the first direction is a direction perpendicular to the optical axis of the projection lens 3 , for example, the first direction is a vertical direction.

[0076] In another example, under the action of an external driving force, the display panel 1 can move relative to the projection lens 3 in a second direction, where the second direction is perpendicular to the optical axis of the projection lens 3. For example, the second direction is Figure 1-Figure 3 The direction perpendicular to the paper.

[0077] In another example, under the action of an external driving force, the display panel 1 can move relative to the projection lens 3 in a third direction. The third direction is not a single direction, but has components of a first direction and a second direction. For example, the first direction is a vertical direction, and the second direction is a vertical direction. Figure 1-Figure 3 The middle direction is perpendicular to the paper surface and faces inward, and the third direction is the composite direction of these two directions.

[0078] For example, referring to Figure 1 , the center position of the display panel 1 coincides with the optical axis position of the projection lens 3 , that is, the movement distance of the display panel 1 relative to the projection lens 3 in the first direction and the second direction are both 0.

[0079] For example, referring to Figure 2 , the display panel 1 moves downward by a distance D1 relative to the projection lens 3 , that is, the display panel 1 is offset by a distance D1 in the vertical direction relative to the optical axis of the projection lens 3 .

[0080] For example, referring to Figure 3 , the display panel 1 moves upward by a distance D1 relative to the projection lens 3 , that is, the display panel 1 is offset by a distance D1 in the vertical direction relative to the optical axis of the projection lens 3 .

[0081] In an embodiment of the present application, the display panel 1 is configured to be movable relative to the projection lens 3 in a direction perpendicular to the optical axis of the projection lens 3, and the offset distance D of the display panel 1 relative to the projection lens 3 is SQRT(D1²+D2²), where D1 is the distance in the vertical direction that the center of the display panel 1 moves relative to the optical axis of the projection lens 3, and D2 is the distance in the direction perpendicular to the paper plane that the center of the display panel 1 moves relative to the optical axis of the projection lens 3.

[0082] In the examples of this application, refer to Figure 4 and Figure 9 The projection lens 3 includes five lenses. Specifically, the projection lens 3 includes a fifth lens 35 with positive optical power, a fourth lens 34 with positive optical power, a third lens 33 with negative optical power, a second lens 32 with positive optical power, and a first lens 31 with positive optical power, which are coaxially arranged in sequence along the light transmission direction. That is, the light transmission path of the projection optical engine is as follows: the light emitted from the display panel 1 passes through the prism assembly 2 and then passes through the fifth lens 35, the fourth lens 34, the third lens 33, the second lens 32, and the first lens 31 in sequence before being emitted.

[0083] Specifically, the fifth lens 35 is closest to the display panel 1. The optical focal length of the fifth lens 35 is positive and is responsible for the initial convergence of light. The optical focal length of the fourth lens 34 is positive, which further enhances the convergence effect of light and adjusts the propagation direction of light. The optical focal length of the third lens 33 is negative, and negative optical focal length is introduced to correct aberrations such as spherical aberration, coma, etc., to improve imaging clarity. The optical focal length of the second lens 32 is positive, which converges light again and optimizes the convergence state of light. The optical focal length of the first lens 31 is positive, and as the front lens of the system, it converges light to ensure that the light is emitted in the best state.

[0084] In the embodiment of the present application, the display panel 1, which is capable of moving relative to the projection lens 3, is combined with the projection lens 3 comprising five lenses to achieve angular deflection of the light emitted from the projection lens 3 while ensuring image quality. The projection optical engine is applied to a near-eye display device, and the deflection angle of the image emitted by the near-eye display device can be adjusted based on the offset distance of the display panel 1 relative to the projection lens 3. The deflection angle of the image emitted by the near-eye display device is consistent with the deflection angle of the light emitted by the projection lens 3.

[0085] The deflection angle b of the chief ray emitted by the projection lens 3 satisfies the following condition: b = FOV * D / h; where D is the offset distance of the center of the display panel 1 relative to the optical axis of the projection lens 3, FOV is the field of view of the projection lens 3, and h is the imaging height of the display panel 1. Where h = tan (FOV / 2) * 2f; f is the total effective focal length of the projection lens 3, and the unit of FOV is radians.

[0086] Specifically, the display panel 1 is configured to be movable relative to the projection lens 3 in a direction perpendicular to the optical axis. The display panel 1 is offset from the projection lens 3 by a distance D. For example, the position of the display panel 1 relative to the projection lens 3 can be adjusted by a drive system, etc., based on actual requirements for the deflection angle.

[0087] The projection lens 3 consists of five lenses arranged sequentially along the light transmission direction, each with a specific optical power distribution (positive, negative, positive, and positive). This design optimizes image quality while also enabling light angle deflection in conjunction with the movement of the display panel 1. In the optical design of the projection lens 3, once the number of lenses and the optical power distribution parameters of each lens are determined, the overall lens architecture and core optical performance are uniquely defined. Specifically, the field of view (FOV) and total effective focal length (f) of the projection lens 3 are parameters that characterize the performance of the projection lens 3. The image height of the display panel 1 is related to the FOV: h = tan(0.5*FOV)*2f. Given the FOV and total effective focal length (f) of the projection lens 3, the image height of the display panel 1 is also determined. For example, with a FOV of 25°, f is 7.4mm, and the image height (half-height) is 1.6mm. For example, with a FOV of 46°, f is 7.4mm, and the image height (half-height) is 3.06mm.

[0088] When the display panel 1 is offset relative to the projection lens 3, the incident angle of light emitted from different positions on the display panel 1 relative to the projection lens 3 changes. This change causes the refraction angle of the light as it passes through the projection lens 3 to also change, thereby deflecting the light angle. Here, b = FOV * D / h, indicating that the deflection angle b is proportional to the offset distance D and inversely proportional to the imaging height h, and is also affected by the field of view (FOV).

[0089] In specific applications, such as near-eye display devices, by adjusting the offset distance D of the display panel 1 relative to the projection lens 3, the deflection angle of the output image can be precisely adjusted according to user needs or application scenarios. This adjustment mechanism enables near-eye display devices to adapt to different users' head postures, differences in interpupillary distances, and changes in viewing angles, providing a more comfortable and personalized viewing experience.

[0090] Therefore, in an embodiment of the present application, a projection optical engine is provided. This projection optical engine is based on an optical architecture of a positionally adjustable display panel 1 and a projection lens 3. While ensuring imaging quality, it deflects the light emitted from the projection lens 3. In a specific application, the deflection angle of the image emitted by the near-eye display device can be adjusted according to the offset distance of the display panel 1 relative to the projection lens 3. In addition, the present application does not require the entire deflection of the projection optical engine to achieve the angular deflection of the image emitted by the projection lens, thereby reducing the space occupied by the projection optical engine, thereby facilitating the miniaturization of the projection optical engine and the near-eye display device.

[0091] In an optional embodiment of the present application, the projection lens 3 includes the above-mentioned five lenses, and the five lenses are only aspherical lenses, among which the fifth lens 35 is made of glass.

[0092] In this embodiment, the projection lens 3 uses five aspherical lenses, which are manufactured using molds, facilitating mass production. Furthermore, the use of five lenses, which share the responsibility of distributing the light angle, ensures that the lens surface shape remains the same while still achieving the desired lens function. This reduces the difficulty of lens manufacturing and facilitates the design of the lens barrel and AR optical module, facilitating mass production.

[0093] In this embodiment, only five lenses are used, and all of them are based on even-order aspherical lenses, which is conducive to achieving the target optical machine parameters with the least number of lenses, and is conducive to achieving the miniaturization and high performance of the AR optical machine.

[0094] In this embodiment, the fifth lens 35 is a glass lens, which is close to the heat source of the projection light engine, which is beneficial to improving the temperature resistance and reliability of the projection light engine.

[0095] In the examples of this application, refer to Figure 4 、 Figure 7-Figure 9 , the first lens 31, the second lens 32, the third lens 33, the fourth lens 34 and the fifth lens 35 satisfy the following condition: 1.5<(f1+f2+f3) / (f4+f5)<1.6;

[0096] Among them, f1 is the effective focal length of the first lens 31, f2 is the effective focal length of the second lens 32, f3 is the effective focal length of the third lens 33, f4 is the effective focal length of the fourth lens 34, and f5 is the effective focal length of the fifth lens 35.

[0097] In this embodiment, the effective focal length relationship of the five lenses is further limited. Through this constraint: 1.5<(f1+f2+f3) / (f4+f5) <1.6, large-angle FOV lens imaging is achieved, thereby allowing the angular deflection of the outgoing light to be achieved by coordinating with the position offset of the display panel 1.

[0098] In this specific embodiment, after being emitted from the display panel 1 , the light passes through the fifth lens 35 (closest to the display panel 1 ), the fourth lens 34 , the third lens 33 , and the second lens 32 in sequence, and finally reaches the first lens 31 .

[0099] The fifth lens 35 and the fourth lens 34 both have positive refractive power and are generally responsible for the initial convergence of light. The third lens 33, the second lens 32, and the first lens 31 are mainly used to further converge light and correct aberrations to form a clear image.

[0100] In this specific embodiment, the distribution of the optical power of the lens group is limited by the ratio of the sum of the effective focal lengths of (f1 + f2 + f3) to (f4 + f5). Specifically, the ratio ranges from (1.5 to 1.6). A ratio greater than 1.5 indicates that the total converging ability of the first lens 31 to the third lens 33 is significantly stronger than that of the fifth lens 35 and the fourth lens 34, which helps to achieve imaging with a large field of view (FOV) because the first lens 31 to the third lens 33 need to quickly converge light to cover a wider viewing angle. A ratio less than 1.6 avoids the over-strong converging ability of the first lens 31 to the third lens 33 and prevents the premature focusing of light, resulting in deterioration of the image quality at the edges (such as field curvature and distortion).

[0101] In this specific embodiment, the optical powers of the first lens 31, the second lens 32, the third lens 33, the fourth lens 34, and the fifth lens 35 act together to expand the field of view of the lens. And through the constraint of the focal length ratio, aberrations such as spherical aberration, coma, and field curvature are balanced, ensuring the imaging clarity at a large field of view. In addition, the focal length ratio constraint ensures that the lens can still maintain the image quality when the display panel 1 is offset.

[0102] Exemplarily, the range of the FOV is: 0° < FOV < 120°, preferably, 60° < FOV < 100°. This range is applicable to any AR with FOV parameters and meets the conventional viewing angle range of the human eye.

[0103] In a further embodiment of the present application, referring to Figure 4 、 Figure 7-Figure 9 the first lens 31, the second lens 32, the third lens 33, the fourth lens 34, and the fifth lens 35 satisfy the following relationships:

[0104] 29mm < f1 < 37mm;

[0105] 8mm < f2 < 10mm;

[0106] -5mm < f3 < -4mm;

[0107] 8mm < f4 < 19mm;

[0108] 7mm < f5 < 14mm.

[0109] Specifically, the f1 focal length of the first lens 31 ranges from 29 mm to 37 mm. Its focal length is significantly greater than that of the other lenses, indicating that it has a strong positive focal power and is primarily responsible for light convergence. Specifically, the first lens 31 is used to rapidly reduce the beam diameter while simultaneously expanding the field of view. The f2 focal length of the second lens 32 ranges from 8 mm to 10 mm. The focal power of the second lens 32 is positive, but weaker than that of the first lens 31. The second lens 32 assists the first lens 31 in converging light and corrects some aberrations (such as spherical aberration and coma). The f3 focal length of the third lens 33 ranges from -5 mm to -4 mm. The third lens 33 has a negative focal power. The third lens 33 is used to diverge light and correct aberrations such as field curvature and distortion. The f4 focal length of the fourth lens 34 ranges from 8 mm to 19 mm. The fourth lens 34 cooperates with the fifth lens 35 to achieve light convergence. The f5 focal length of the fifth lens 35 ranges from 7 mm to 14 mm. The fifth lens 35 is used for preliminary light convergence.

[0110] In this embodiment, high-definition and wide-angle projection imaging is achieved through the strong focusing capabilities of the first lens 31 and the second lens 32 and the aberration correction of the third lens 33.

[0111] In this embodiment, the coordinated design of the negative power lens and the positive power lens ensures the image quality stability of the system under the conditions of field of view expansion and dynamic offset of the display panel 1 .

[0112] In this embodiment, the focal length of each lens in the projection lens 3 is limited to ensure the processability and mass production of each lens in the projection lens 3 .

[0113] In further embodiments of the present application, reference is made to Figure 4 、 Figure 7-Figure 9 , the first lens 31, the second lens 32, the third lens 33, the fourth lens 34 and the fifth lens 35 satisfy the following relationship:

[0114] 4<f 1 / f<5.0;

[0115] 1.1<f 2 / f<1.3;

[0116] -0.7<f 3 / f<-0.6;

[0117] 1.2<f 4 / f<2.5;

[0118] 1<f 5 / f<2;

[0119] Wherein, f is the total effective focal length of the projection lens 3 .

[0120] In this embodiment, the effective focal lengths of the lenses in projection lens 3 are further defined. The f1 ratio of first lens 31 is 4 < f1 / f < 5.0, indicating that the positive focal power of first lens 31 is significantly stronger than that of other lenses. First lens 31 rapidly reduces the beam diameter and expands the field of view. The f2 ratio of second lens 32 is 1.1 < f2 / f < 1.3, assisting first lens 31 in converging light and correcting some aberrations. The f3 ratio of third lens 33 is -0.7 < f3 / f < -0.6, indicating that third lens 33 has negative focal power. Third lens 33 is used to diverge light and correct aberrations such as field curvature and distortion. The f4 ratio of fourth lens 34 is 1.2 < f4 / f < 2.5, cooperating with fifth lens 35 to achieve preliminary convergence of light. The f5 ratio of fifth lens 35 is 1 < f5 / f < 2, providing preliminary convergence of light.

[0121] In this embodiment, the focal length ratio design of the lens group ensures that the lens can maintain image quality when the display panel 1 is offset.

[0122] In this embodiment, the optical power of the projection lens 3 is ensured to be evenly distributed, which is beneficial to controlling aberrations, improving image quality, and reducing tolerance sensitivity.

[0123] In further embodiments of the present application, reference is made to Figure 4 、 Figure 7-Figure 9 , the first lens 31, the second lens 32, the third lens 33, the fourth lens 34 and the fifth lens 35 satisfy the following relationship:

[0124] 2.6<(f1+f2+f3) / L<3.1;

[0125] 1.6<(f4+f5) / L<2.0;

[0126] Wherein, L is the total optical length of the projection optical machine.

[0127] In this embodiment, 2.6 < (f1 + f2 + f3) / L < 3.1, indicating that the combined focal lengths of the first through third lenses 31 through 33 account for a significant portion of the total optical length. Specifically, the positive power of the first and second lenses 31 and 32 facilitates rapid light convergence, extending the field of view. The negative power of the third lens 33 balances excess light convergence, correcting aberrations such as field curvature and distortion.

[0128] 1.6 < (f4 + f5) / L < 2.0, indicating that the combined focal lengths of the fourth and fifth lenses 34, 35 account for a relatively small proportion of the total optical length. Specifically, the positive refractive powers of the fourth and fifth lenses 34, 35 provide initial light convergence and, in conjunction with the first, second, and fourth lenses 31, 32, 34, correct aberrations (such as astigmatism and chromatic aberration).

[0129] In this embodiment, the effective focal length of the lens in the projection lens 3 is limited to balance the field of view and image quality. The ratio design of the lens focal length combination and the total optical length provides optical compensation space for the offset of the display panel 1, enhancing the flexibility of the projection optical engine design.

[0130] In addition, the optical system length is optimized while ensuring the imaging quality, which is conducive to the miniaturization design of the projection optical machine.

[0131] In the examples of this application, refer to Figure 4 、 Figure 7-Figure 9 The air gap between the first lens 31 and the second lens 32 is A1, the air gap between the second lens 32 and the third lens 33 is A2, the air gap between the third lens 33 and the fourth lens 34 is A3, the air gap between the fourth lens 34 and the fifth lens 35 is A4, and the air gap between the fifth lens 35 and the prism assembly 2 in the projection optical machine is A5;

[0132] Among them, 1.0<(A1+A2) / (A3+A4+A5)<1.1.

[0133] In this embodiment, light is emitted from the display panel 1 , is first deflected by the prism assembly 2 , and then passes through the fifth lens 35 to the first lens 31 in sequence before finally being emitted.

[0134] Specifically, by designing the ratio of A1+A2 to A3+A4+A5, a balance between the strong focusing capability and the aberration correction capability of the projection lens 3 is achieved, thereby improving the overall imaging quality.

[0135] This constraint, 1.0 < (A1 + A2) / (A3 + A4 + A5) < 1.1, ensures that the focusing capability of projection lens 3 is coordinated with the optimized angle of light incident on the prism. A ratio close to 1 indicates a balanced distribution of lens group gaps, helping to optimize the optical system length while maintaining image quality.

[0136] In this embodiment, the air gaps between adjacent lenses in the projection lens 3 are defined, and the air gaps are evenly arranged, which is beneficial to structural design and also helps to reduce tolerance sensitivity.

[0137] In a further embodiment of the present application, the projection light engine satisfies:

[0138] 0.1<(A1+A2) / L<0.2;

[0139] 0.1<(A3+A4+A5) / L<0.2;

[0140] Wherein, L is the total optical length of the projection optical machine.

[0141] In this embodiment, by limiting the proportion of the air gap in the total optical length, it is avoided that the lens group spacing is too large, which leads to an excessively long system length, while ensuring sufficient gap for aberration correction.

[0142] Through this constraint, 0.1<(A1+A2) / L<0.2, 0.1<(A3+A4+A5) / L<0.2, indicating that the air gap from the first lens 31 to the third lens 33 and the air gap from the third lens 33 to the prism assembly 2 occupy a similar and reasonable proportion in the total optical length, and the air gap from the first lens 31 to the third lens 33 and the air gap from the third lens 33 to the prism assembly 2 are distributed more evenly, which helps to achieve high performance in a compact design.

[0143] In the embodiment of the present application, the projection light engine satisfies:

[0144] 0.45<h / L<0.60, wherein L is the total optical length of the projection optical machine.

[0145] In this embodiment, the optical system of the projection engine consists of a display panel 1, a prism assembly 2, and a lens system (e.g., first lens 31 through fifth lens 35). Light emitted from the display panel 1 passes through the prism assembly 2 and the lens system in sequence, ultimately forming a projected image. The image height h is specifically defined as the height of the effective imaging area of the display panel 1 and directly affects the field of view and resolution of the projected image. The total optical length L is specifically defined as the total optical path length from the display panel 1 to the final imaging plane, reflecting the compactness of the system.

[0146] A larger image height h supports a wider field of view (FOV), thereby improving the coverage of the projected image. A smaller L enables a more compact system design, suitable for portable or space-constrained applications.

[0147] By constraining 0.45<h / L<0.60, it indicates that the image height occupies a large proportion of the total optical length, while avoiding the system length being too long, achieving a balance between a large field of view and compactness.

[0148] When projection optical engines are used in near-eye display devices, a precise design of the image height to total optical length ratio is used to achieve a large field of view and high-resolution imaging effect, while keeping the device compact and enhancing the immersive experience.

[0149] The following is a detailed description of the projection optical machine provided in the embodiment of the present application:

[0150] Example 1

[0151] Based on a 640*480*4μm μLED panel (half-image height 1.6mm), a 25° FOV, and varying the offset distance D of display panel 1 relative to projection lens 3, the projection engine can deflect the emitted light at different angles. In near-eye display devices, the deflection angle of the main light ray emitting from the image in these devices is consistent with the deflection angle of the main light ray emitted by projection lens 3.

[0152] For example, based on a 640*480*4μm μLED panel (half-image height 1.6mm), a FOV of 25°, and offset distance D between display panel 1 and projection lens 3, the projector can achieve an angular deflection of the emitted light between 0° and ±10.5°. The projector has an overall optical length (L) of 13mm, an entrance pupil diameter of 3.7mm, an F-number of 2.0, an EFFL of 7.4mm, and a wavelength ratio of 463nm, 527nm, and 635nm, respectively, in a ratio of 1:2:1.

[0153] Reference Figure 4 The specific parameters of the projection lens 3 are shown in Table 1 below, which include the curvature radius, thickness, glass material, and semi-aperture of the lens.

[0154] Table 1:

[0155]

[0156] Reference Figure 5 The MTF diagram corresponding to the projection optical machine of the embodiment of the present application shows that the average MTF of each field of view is greater than 0.57 @125lp / mm (Nyquist frequency), and the imaging is good.

[0157] Reference Figure 6 The defocus MTF diagram corresponding to the projection optical machine of the embodiment of the present application shows that the defocus range of MTF>0.3 @ 125lp / mm (Nyquist frequency) is greater than 0.018mm, which has a larger defocus range and is conducive to improving imaging quality.

[0158] In a specific embodiment, based on the above parameter definition, refer to Figure 7 In the actual application of 0.13″ μLED, the center of the display panel 1 coincides with the optical axis of the projection lens 3, that is, the offset angle of the main light of the projection lens 3 is 0°, which can achieve an image height of 3.2mm and an imaging FOV of 25°. At this time, the lens imaging FOV range is -12.5° to 12.5°.

[0159] In another specific embodiment, based on the above parameter definition, refer to Figure 8In actual applications of 0.13″ μLEDs, the center of the display panel 1 is offset relative to the optical axis of the projection lens 3. Specifically, the center of the display panel 1 is vertically displaced by 1.46 mm relative to the optical axis of the projection lens 3. The offset angle of the chief ray of the projector's output light is 10.5°, and the image height is 3.2 mm, corresponding to an imaging FOV of 25°. At this time, the imaging FOV used by the projection lens 3 is in the range of 21° to 46°.

[0160] Example 2

[0161] Based on a 640*480*4μm μLED panel (half-image height 1.6mm), a 25° FOV, and varying the offset distance D of display panel 1 relative to projection lens 3, the projection engine can deflect the emitted light at different angles. In near-eye display devices, the deflection angle of the main light ray emitting from the image in these devices is consistent with the deflection angle of the main light ray emitted by projection lens 3.

[0162] For example, based on a 640*480*4μm μLED panel (half-image height 1.6mm), a FOV of 25°, and offset distance D between display panel 1 and projection lens 3, the projector can achieve an angular deflection of the emitted light between 0° and ±10.5°. The projector has an overall optical length (L) of 13mm, an entrance pupil diameter of 3.7mm, an F-number of 2.0, an EFFL of 7.4mm, and a wavelength ratio of 463nm, 527nm, and 635nm, respectively, in a ratio of 1:2:1.

[0163] Reference Figure 9 The specific parameters of the projection lens 3 are shown in Table 2 below, which include the curvature radius, thickness, glass material, and semi-aperture of the lens.

[0164] Table 2:

[0165]

[0166] Reference Figure 10 The MTF diagram corresponding to the projection optical machine of the embodiment of the present application shows that the average MTF of each field of view is greater than 0.3 @125lp / mm (Nyquist frequency), and the imaging is good.

[0167] The present application also provides a near-eye display device. The near-eye display device includes the aforementioned optical projection engine and waveguide device 4 , wherein the optical projection engine is located in an incoupling region 41 of the waveguide device 4 , and the outcoupling region 42 of the waveguide device 4 is configured to couple image light that matches the location of the display panel 1 .

[0168] In this embodiment, the projection optical engine is applied to a near-eye display device. By adjusting the offset distance D of the display panel 1 relative to the projection lens 3, the deflection angle b of the main light of the output image of the near-eye display device can be changed, thereby dynamically adjusting the coverage range of the coupled-out light to meet the needs of different users.

[0169] In one embodiment, a stop is provided on the side of the first lens 31 of the optical projection machine facing away from the second lens 32 , and the aperture size of the stop satisfies the following: 2.5 mm < pupil < 4.5 mm.

[0170] Specifically, the aperture of the projection optical machine is a front aperture, which is located in front of the first lens 31 , and the aperture size satisfies: 2.5 mm < pupil < 4.5 mm.

[0171] In this embodiment, the exit pupil diaphragm of the projection engine (e.g., an AR engine) and the coupling region 41 of the light guide (e.g., a waveguide) must match in size to ensure efficient light beam coupling. Furthermore, diaphragm size deviations can lead to aberrations (e.g., pincushion distortion). A matching design minimizes optical distortion and ensures a clear image.

[0172] Optionally, the distance d from the first lens 31 to the aperture surface satisfies: 0≤d<2mm.

[0173] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0174] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present application. It should be understood by those skilled in the art that the above examples may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A projection light machine, characterized in that: The projection optical machine comprises a display panel (1) and a projection lens (3), wherein the display panel (1) is configured to be movable relative to the projection lens (3) in a direction perpendicular to the optical axis of the projection lens (3) so as to deflect light emitted from the projection lens (3); The projection lens (3) comprises a fifth lens (35) with positive optical power, a fourth lens (34) with positive optical power, a third lens (33) with negative optical power, a second lens (32) with positive optical power, and a first lens (31) with negative optical power, which are coaxially arranged in sequence along the light transmission direction; Wherein, the deflection angle b of the main light of the projection lens (3) meets the following conditions: b=FOV*D / h; Wherein, D is the offset distance of the center of the display panel (1) relative to the optical axis of the projection lens (3), FOV is the field of view angle of the projection lens (3), and h is the imaging height of the display panel (1).

2. The projection light engine according to claim 1, wherein: The first lens (31), the second lens (32), the third lens (33), the fourth lens (34) and the fifth lens (35) satisfy the following condition: 1.5<(f1+f2+f3) / (f4+f5) <1.6; Wherein, f1 is the effective focal length of the first lens (31), f2 is the effective focal length of the second lens (32), f3 is the effective focal length of the third lens (33), f4 is the effective focal length of the fourth lens (34), and f5 is the effective focal length of the fifth lens (35).

3. The projection light engine according to claim 1 or 2, characterized in that: The first lens (31), the second lens (32), the third lens (33), the fourth lens (34) and the fifth lens (35) satisfy the following relationship: 29mm<f1<37mm; 8mm<f2<10mm; -5mm<f3<-4mm; 8mm<f4<19mm; 7mm<f5<14mm.

4. The projection light engine according to claim 1 or 2, characterized in that: The first lens (31), the second lens (32), the third lens (33), the fourth lens (34) and the fifth lens (35) satisfy the following relationship: 4< f 1 / f <5.0; 1.1< f 2 / f <1.3; -0.7< f 3 / f <-0.6; 1.2< f 4 / f <2.5; 1< f 5 / f <2; Wherein, f is the total effective focal length of the projection lens (3).

5. The projection light engine according to claim 1 or 2, characterized in that: The first lens (31), the second lens (32), the third lens (33), the fourth lens (34) and the fifth lens (35) satisfy the following relationship: 2.6<(f1+f2+f3) / L<3.1; 1.6<(f4+f5) / L<2.0; Wherein, L is the total optical length of the projection optical machine.

6. The projection light engine according to claim 1, wherein: The air gap between the first lens (31) and the second lens (32) is A1, the air gap between the second lens (32) and the third lens (33) is A2, the air gap between the third lens (33) and the fourth lens (34) is A3, the air gap between the fourth lens (34) and the fifth lens (35) is A4, and the air gap between the fifth lens (35) and the prism assembly (2) in the projection optical machine is A5; Among them, 1.0<(A1+A2) / (A3+A4+A5)<1.

1.

7. The projection light engine according to claim 6, wherein: The projection light engine meets the following requirements: 0.1<(A1+A2) / L<0.2; 0.1<(A3+A4+A5) / L<0.2; Wherein, L is the total optical length of the projection optical machine.

8. The optical projection machine according to claim 1, wherein: The projection light engine meets the following requirements: 0.45<h / L<0.60, wherein L is the total optical length of the projection optical machine.

9. A near-eye display device, characterized in that: The near-eye display device comprises a projection light engine and a waveguide device (4) as described in any one of claims 1 to 8, wherein the projection light engine is located in a coupling-in region (41) of the waveguide device (4), and the coupling-out region (42) of the waveguide device (4) is used to couple out image light that matches the setting position of the display panel (1).

10. The near-eye display device according to claim 9, wherein: A diaphragm is provided on the side of the first lens (31) of the projection optical machine facing away from the second lens (32), and the aperture size of the diaphragm satisfies the following: 2.5 mm < pupil < 4.5 mm.

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