Projection ray machine and near-to-eye display equipment

Abstract

The embodiment of the invention provides a projection light machine and near-to-eye display equipment. The projection light machine comprises a display panel and a projection lens, and the display panel is configured to be capable of moving in the direction perpendicular to the optical axis of the projection lens relative to the projection lens so that light emitted by the projection lens can deflect; the projection lens comprises a fifth lens with positive focal power, a fourth lens with positive focal power, a third lens with negative focal power, a second lens with positive focal power and a first lens with negative focal power which are coaxial and are sequentially arranged along the light transmission direction; the deflection angle b of the main light of the emergent light of the projection lens meets 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 angle of the projection lens, and h is the imaging height of the display panel.

Description

Technical Field

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

[0002] Currently, the display screen presentation methods of most AR devices are relatively limited, and the viewing angle of their screens is usually fixed within a preset range. Even if some devices support the deflection adjustment of the display angle of the screen, this function mainly relies on the optimization and modulation of software algorithms to achieve, rather than direct adjustment at the hardware level.

[0003] In addition, in the design of the optical machine, the existing solutions generally adopt a 0° design with a fixed outgoing light direction. After being matched with the waveguide component, this design results in the final image projected onto the human eye being also limited within a fixed viewing angle range and being difficult to flexibly adjust according to user needs or environmental changes.

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

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

[0006] In a first aspect, embodiments of the present application provide a projection optical machine. The projection optical machine 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 a positive optical power, a fourth lens with a positive optical power, a third lens with a negative optical power, a second lens with a positive optical power, and a first lens with a negative optical power, which are coaxially arranged in the light transmission direction in sequence; The deflection angle b of the chief ray of the light emitted by the projection lens satisfies the following condition: b = FOV * D / h; where 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 angle of the projection lens, and h is the imaging height of the display panel.

[0007] 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; Wherein, 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.

[0008] Optionally, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens satisfy the following relationships: 29mm < f1 < 37mm; 8mm < f2 < 10mm; -5mm < f3 < -4mm; 8mm < f4 < 19mm; 7mm < f5 < 14mm.

[0009] Optionally, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens satisfy the following relationships: 4 < f1 / f < 5.0; 1.1 < f2 / f < 1.3; -0.7 < f3 / f < -0.6; 1.2 < f4 / f < 2.5; 1 < f5 / f < 2; Wherein, f is the total effective focal length of the projection lens.

[0010] Optionally, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens satisfy the following relationships: 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.

[0011] 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; Wherein, 1.0 < (A1 + A2) / (A3 + A4 + A5) < 1.1. Optionally, the projection optical machine satisfies: 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 Optionally, the projection optical machine satisfies: 0.45<h / L<0.60, wherein L is the total optical length of the projection optical machine.

[0012] In a second aspect, an embodiment of the present application further provides a near-eye display device. The near-eye display device comprises a projection optical machine and a waveguide device as described above, wherein the projection optical machine is located in a coupling-in region of the waveguide device, and the coupling-out region of the waveguide device is used to couple out image light that matches the setting position of the display panel.

[0013] Optionally, a diaphragm is provided on the side of the first lens of the projection optical machine facing away from the second lens, and an aperture size of the diaphragm satisfies: 2.5 mm<pupil<4.5 mm.

[0014] A technical effect of this application is: The embodiment of the present application provides a projection optical machine, which is based on a positionally adjustable display panel to deflect the light emitted by the projection lens. 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 relative to the projection lens. In addition, the present application does not need to realize the image angle deflection by overall deflection of the projection optical machine, which reduces the space volume occupied by the projection optical machine, thereby facilitating the miniaturization of the projection optical machine and the near-eye display device.

[0015] 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

[0016] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.

[0017] Figures 1-3 Shown is a structural diagram of a near-eye display device provided in an embodiment of the present application.

[0018] Figure 4 The optical structure of the projection lens provided in the embodiment of the present application is shown as follows Figure 1 .

[0019] Figure 5 Shown Figure 4 MTF diagram of the projection lens.

[0020] Figure 6 Shown Figure 4 Through-focus MTF diagram of the projection lens.

[0021] Figure 7 ShownFigure 4 The optical light path of the projection lens after the display panel moves in the corresponding projection optical machine Figure 1 。

[0022] Figure 8 As shown Figure 4 The optical light path of the projection lens after the display panel moves in the corresponding projection optical machine Figure 2 。

[0023] Figure 9 As shown is the optical architecture of the projection lens provided by the embodiment of the present application Figure 2 。

[0024] Figure 10 As shown Figure 9 The MTF diagram of the corresponding projection optical machine

[0025] Explanation of reference numerals: 1. Display panel; 2. Prism assembly; 3. Projection lens; 31. First lens; 32. Second lens; 33. Third lens; 34. Fourth lens; 35. Fifth lens; 4. Waveguide device; 41. Coupling-in region; 42. Coupling-out region. Detailed implementation manners

[0026] Now, various exemplary embodiments of the present application will 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 values set forth in these embodiments do not limit the scope of the present application.

[0027] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way a limitation on the present application and its application or use.

[0028] Technologies and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies and devices should be regarded as part of the specification.

[0029] In all the examples shown and discussed herein, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0030] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0031] Embodiments of the present application provide a projection optical engine. For example, the projection optical engine can be an AR optical engine, and the AR optical engine can be a Micro LED optical engine, an LCoS optical engine, or a DLP optical engine. The projection optical engine cooperates with a waveguide device 4 to provide a near-eye display device. For example, the near-eye display device can be an AR device, and the AR device can be an AR glasses, etc.

[0032] Referring to Figures 1-3 and Figure 4 , Figures 7-9 , the projection optical engine includes: a display panel 1 and a projection lens 3. 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. The projection lens 3 includes a fifth lens 35 with a positive optical power, a fourth lens 34 with a positive optical power, a third lens 33 with a negative optical power, a second lens 32 with a positive optical power, and a first lens 31 with a negative optical power, which are arranged coaxially and successively along the light transmission direction. The deflection angle b of the chief ray of the light 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 angle of the projection lens 3, and h is the imaging height of the display panel 1.

[0033] In the embodiments 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 projection image.

[0034] In addition, in order to further optimize the optical path design and improve the projection effect, a prism assembly 2, such as an Xcube prism, is particularly added in the optical path between the display panel 1 and the projection lens 3. This not only helps with the effective refraction and convergence of light, but also corrects aberrations to a certain extent, thereby ensuring that the finally projected image has higher clarity and color reproducibility. In the embodiments 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, so as to deflect the light emitted by the projection lens 3.

[0035] For example, the movement of the display panel 1 is realized through a mechanical structure or a drive system, ensuring the accuracy and stability of the offset. Those skilled in the art can select different mechanical structures or drive systems according to the actual application scenarios and requirements to realize the movement of the display panel 1, which will not be elaborated in the embodiments of the present application.

[0036] When the display panel 1 moves relative to the projection lens 3 in a direction perpendicular to the optical axis, the incident angles of the light rays emitted from different positions of the display panel 1 relative to the projection lens 3 will change. This change in the incident angle will cause the refraction angle of the light rays when passing through the projection lens 3 to also change, thereby changing the propagation direction of the light rays.

[0037] Since each point on the display panel 1 corresponds to a pixel on the projection image, when the display panel 1 moves, the light rays emitted from these pixels will also deflect accordingly. This deflection is overall, that is, the entire projection image will deflect as the display panel 1 moves, thereby achieving the control of the deflection of the light rays emitted from 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 projection image can be flexibly controlled to adapt to different projection scenarios and requirements.

[0038] In a specific application scenario, the projection optical machine is applied to a near-eye display device, and the display screen of the near-eye display device 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 to keep the virtual image synchronized with the wearer's line of sight direction, improving the experience of wearing the near-eye display device.

[0039] In another specific application scenario, by adjusting the position of the display panel 1 relative to the projection lens 3, the outgoing image of the projection lens 3 can be deflected, and the position of the outgoing image of the projection optical machine can be adjusted.

[0040] In the embodiments of the present application, the display panel 1 being configured to be able to move relative to the projection lens 3 in a direction perpendicular to the optical axis of the projection lens 3 can be understood as the following three cases: 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, and the first direction is a direction perpendicular to the optical axis of the projection lens 3. For example, the first direction is the vertical direction.

[0041] 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, and the second direction is a direction perpendicular to the optical axis of the projection lens 3. For example, the second direction is Figures 1-3 the direction perpendicular to the paper surface in the figure.

[0042] In yet 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, and the third direction is not a single direction. The third direction has components in the first direction and the second direction. For example, the first direction is the vertical direction, and the second direction is Figures 1-3 the direction perpendicular to the paper surface and into the paper in the figure, and the third direction is the composite direction after the combination of these two directions.

[0043] Exemplarily, referring to Figure 1 , the central position of the display panel 1 coincides with the optical axis position of the projection lens 3, that is, the moving distances of the display panel 1 relative to the projection lens 3 in the first direction and the second direction are both 0.

[0044] Exemplarily, referring to Figure 2 , the display panel 1 moves downward by a distance D1 relative to the projection lens 3, that is, the offset distance of the display panel 1 relative to the optical axis of the projection lens 3 in the vertical direction is D1.

[0045] Exemplarily, referring to Figure 3 , the display panel 1 moves upward by a distance D1 relative to the projection lens 3, that is, the offset distance of the display panel 1 relative to the optical axis of the projection lens 3 in the vertical direction is D1.

[0046] In the embodiment of the present application, the display panel 1 is configured to be able to move relative to the projection lens 3 in a direction perpendicular to the optical axis of the projection lens 3. The offset distance D of the display panel 1 relative to the projection lens 3 is D = SQRT(D1² + D2²), where D1 is the moving distance of the center of the display panel 1 relative to the optical axis of the projection lens 3 in the vertical direction, and D2 is the moving distance of the center of the display panel 1 relative to the optical axis of the projection lens 3 in the direction perpendicular to the paper surface.

[0047] In the embodiment of the present application, referring to Figure 4 and Figure 9 , the projection lens 3 includes five lenses. Specifically, the projection lens 3 includes a fifth lens 35 with a positive optical power, a fourth lens 34 with a positive optical power, a third lens 33 with a negative optical power, a second lens 32 with a positive optical power, and a first lens 31 with a positive optical power, which are coaxially arranged in the light transmission direction. That is, the light transmission optical path of the projection optical machine is: 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 and is emitted.

[0048] Specifically, the fifth lens 35 is closest to the display panel 1 and has a positive optical power, responsible for initially converging the light. The fourth lens 34 has a positive optical power to further enhance the light converging effect and adjust the light propagation direction. The third lens 33 has a negative optical power to introduce negative optical power to correct aberrations such as spherical aberration and coma, and improve the imaging clarity. The second lens 32 has a positive optical power to converge the light again and optimize the light convergence state. The first lens 31 has a positive optical power and, as the front lens of the system, converges the light to ensure that the light is emitted in the best state.

[0049] In the embodiment of the present application, the display panel 1 that can move relative to the projection lens 3, in combination with the projection lens 3 including five lenses, can achieve the angular deflection of the light rays emitted by the projection lens 3 while ensuring the imaging quality. The projection optical engine is applied to a near-eye display device, and the deflection angle of the image output 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. The deflection angle of the image output by the near-eye display device is consistent with the deflection angle of the light rays emitted by the projection lens 3.

[0050] Among them, the deflection angle b of the principal ray of the light rays 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 angle of the projection lens 3, and h is the imaging height of the display panel 1. Among them, h = tan(FOV / 2) * 2f; f is the total effective focal length of the projection lens 3, and the unit of FOV is radians.

[0051] Specifically, the display panel 1 is configured to be able to move relative to the projection lens 3 in a direction perpendicular to the optical axis. The offset distance of the display panel 1 relative to the projection lens 3 is D. For example, according to the actual requirements of the deflection angle, the position of the display panel 1 relative to the projection lens 3 is adjusted through a driving system or the like.

[0052] The projection lens 3 is composed of five lenses, arranged in sequence along the light transmission direction, and has a specific focal power distribution (positive, positive, negative, positive, positive). This design aims to optimize the imaging quality and, at the same time, cooperate with the movement of the display panel 1 to achieve the deflection of the light angle. In the optical design of the projection lens 3, when the number of lenses and the parameters of the focal power distribution of each lens are set, the overall structure and core optical performance of the lens are uniquely determined. Specifically, the field of view angle (FOV) and the total effective focal length (f) of the projection lens 3 are determined as parameters that can characterize the performance of the projection lens 3. There is a correlation between the imaging height of the display panel 1 and the field of view angle FOV, h = tan(0.5 * FOV) * 2f. When the field of view angle (FOV) and the total effective focal length (f) of the projection lens 3 are determined, the imaging height of the display panel 1 is also determined accordingly. For example, when FOV is 25°, f is 7.4 mm, and the image height (half image height) is 1.6 mm. For example, when FOV is 46°, f is 7.4 mm, and the image height (half image height) is 3.06 mm.

[0053] When the display panel 1 is offset relative to the projection lens 3, the incident angles of the light rays emitted from different positions of the display panel 1 relative to the projection lens 3 will change. This change causes the refraction angles of the light rays when passing through the projection lens 3 to also change, thereby achieving the deflection of the light angle. Among them, b = FOV * D / h, which indicates 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 angle FOV.

[0054] In a specific application, for example, in 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 of the outgoing image can be precisely adjusted according to user requirements or application scenarios. This adjustment mechanism enables the near-eye display device to adapt to different users' head postures, pupil distance differences, and viewing angle changes, providing a more comfortable and personalized viewing experience.

[0055] Therefore, in the embodiment of the present application, a projection optical machine is provided. Based on the optical architecture of the position-adjustable display panel 1 and the projection lens 3, while ensuring the imaging quality, the light emitted by the projection lens 3 is deflected. In a specific application, the deflection angle of the outgoing image of 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, in the present application, the angle deflection of the outgoing image of the projection lens can be achieved without the need to deflect the entire projection optical machine, reducing the space volume occupied by the projection optical machine, which is conducive to the miniaturization of the projection optical machine and the near-eye display device.

[0056] In an alternative embodiment of the present application, the projection lens 3 includes the above five lenses, and the five lenses are only aspherical lenses, and the fifth lens 35 is made of glass.

[0057] In this embodiment, the projection lens 3 uses 5 aspherical lenses, and its production and processing are based on molds, which is conducive to mass production. In addition, by using 5 lenses to jointly bear and distribute the light angle, it can be ensured that the lens surface type is a conventional surface type to achieve the lens index function, reducing the lens processing difficulty, and is helpful for designing the lens barrel and the AR optical machine module, which is conducive to mass production; In this embodiment, only 5 lenses are used, and all are based on even aspherical lenses, which is conducive to achieving the target optical machine parameters with the fewest lenses, and is conducive to the miniaturization and high performance of the AR optical machine.

[0058] In this embodiment, the fifth lens 35 is a glass lens, close to the heat source of the projection optical machine, which is conducive to improving the temperature resistance and reliability of the projection optical machine.

[0059] In the embodiment of the present application, referring to Figure 4 、 Figures 7-9 , the first lens 31, the second lens 32, the third lens 33, the fourth lens 34, and the fifth lens 35 satisfy the following conditions: 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.

[0060] In this embodiment, the relationship of the effective focal lengths of the five lenses is further defined. 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 realized in cooperation with the position offset of the display panel 1.

[0061] In this specific embodiment, after the light exits from the display panel 1, it sequentially passes through the fifth lens 35 (closest to the display panel 1), the fourth lens 34, the third lens 33, the second lens 32, and finally reaches the first lens 31.

[0062] Wherein, the optical powers of the fifth lens 35 and the fourth lens 34 are both positive, and they usually undertake the preliminary light converging task. The third lens 33, the second lens 32, and the first lens 31 mainly realize the further convergence of light and the correction of aberrations to form a clear image.

[0063] In this specific embodiment, the distribution of the optical power of the lens group is restricted by the ratio of the sum of the effective focal lengths of (f1 + f2 + f3) to (f4 + f5). Specifically, the ratio range is (1.5 to 1.6). Wherein, 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 large field of view (FOV) imaging 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 the deterioration of the image quality at the edge (such as field curvature and distortion).

[0064] In this specific embodiment, the optical powers of the first lens 31, the second lens 32, the third lens 33, and the fourth lens 34 and the fifth lens 35 act together to expand the field of view of the lens. And through the focal length ratio constraint, aberrations such as spherical aberration, coma, and field curvature are balanced to ensure 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.

[0065] Exemplarily, the range of FOV is: 0° < FOV < 120°, preferably, 60° < FOV < 100°. This range is applicable to any AR with FOV parameters and satisfies the conventional viewing angle range of the human eye.

[0066] In a further embodiment of the present application, with reference to Figure 4 、Figures 7-9 , 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: 29mm < f1 < 37mm; 8mm < f2 < 10mm; -5mm < f3 < -4mm; 8mm < f4 < 19mm; 7mm < f5 < 14mm.

[0067] Specifically, the focal length range of the first lens 31, f1: 29mm to 37mm. The focal length of the first lens 31 is significantly greater than that of other lenses, indicating that it is a strong positive refractive power lens and undertakes the main task of converging light. Specifically, the first lens 31 is used to quickly reduce the beam diameter and at the same time expand the field of view angle. The focal length range of the second lens 32, f2: 8mm to 10mm. The refractive 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 focal length range of the third lens 33, f3: -5mm to -4mm. The third lens 33 is a negative refractive power lens. The third lens 33 is used to diverge light and correct aberrations such as field curvature and distortion. The focal length range of the fourth lens 34, f4: 8mm to 19mm. The fourth lens 34 is used to cooperate with the fifth lens 35 to converge light. The focal length range of the fifth lens 35, f5: 7mm to 14mm. The fifth lens 35 is used to initially converge light.

[0068] In this embodiment, through the strong converging ability of the first lens 31 and the second lens 32 and the aberration correction of the third lens 33, high-definition and large-field-of-view projection imaging is achieved.

[0069] In this embodiment, the collaborative design of the negative refractive power lens and the positive refractive power lens ensures the image quality stability of the system under the expansion of the field of view angle and the dynamic offset of the display panel 1.

[0070] In this embodiment, the focal length of each lens in the projection lens 3 is limited to ensure the processability and mass producibility of each lens in the projection lens 3.

[0071] In a further embodiment of the present application, referring to Figure 4 , Figures 7-9 , 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: 4 < f1 / f < 5.0; 1.1 < f2 / f < 1.3; -0.7 < f3 / f < -0.6; 1.2 < f4 / f < 2.5; 1 < f5 / f < 2; Wherein, f is the total effective focal length of the projection lens 3.

[0072] In this embodiment, the effective focal lengths of the lenses in the projection lens 3 are further limited. The f1 ratio range of the first lens 31: 4 < f1 / f < 5.0, indicating that the positive optical power of the first lens 31 is significantly stronger than that of other lenses. The first lens 31 rapidly reduces the beam diameter and expands the field of view angle. The f2 ratio range of the second lens 32: 1.1 < f2 / f < 1.3. The second lens 32 is used to assist the first lens 31 in converging light and correcting some aberrations. The f3 ratio range of the third lens 33: -0.7 < f3 / f < -0.6, indicating that the third lens 33 is a negative optical power lens. The third lens 33 is used to diverge light and correct aberrations such as field curvature and distortion. The f4 ratio range of the fourth lens 34: 1.2 < f4 / f < 2.5. The fourth lens 34 is used to cooperate with the fifth lens 35 to achieve preliminary convergence of light. The f5 ratio range of the fifth lens 35: 1 < f5 / f < 2. The fifth lens 35 is used to preliminarily converge light.

[0073] In this embodiment, the focal length ratio design of the lens group ensures that the image quality can still be maintained when the display panel 1 is offset.

[0074] In this embodiment, the uniform distribution of the optical power of the projection lens 3 is ensured, which is beneficial to controlling aberrations, improving image quality, and reducing tolerance sensitivity.

[0075] In a further embodiment of the present application, referring to Figure 4 , Figures 7-9 , 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: 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.

[0076] In this embodiment, 2.6 < (f1 + f2 + f3) / L < 3.1, indicating that the total focal length of the first lens 31 to the third lens 33 accounts for a relatively large proportion of the total optical length. Specifically, the positive optical powers of the first lens 31 and the second lens 32 dominate the rapid convergence of light and expand the field of view angle. The negative optical power of the third lens 33 balances the excessive convergence of the lens and corrects aberrations such as field curvature and distortion.

[0077] 1.6 < (f4 + f5) / L < 2.0 indicates that the total focal length of the fourth lens 34 and the fifth lens 35 accounts for a relatively small proportion of the total optical length. Specifically, the positive optical power of the fourth lens 34 and the fifth lens 35 preliminarily converges the light rays, and in cooperation with the first lens 31, the second lens 32, and the fourth lens 34, corrects aberrations (such as astigmatism and chromatic aberration).

[0078] In this embodiment, by defining the effective focal lengths of the lenses in the projection lens 3, the field of view angle and the image quality are balanced. The ratio design of the lens focal length combination to the total optical length provides an optical compensation space for the offset of the display panel 1, enhancing the flexibility of the projection optical machine design.

[0079] In addition, while ensuring the imaging quality, the length of the optical system is optimized, which is beneficial to the miniaturization design of the projection optical machine.

[0080] In the embodiment of the present application, referring to Figure 4 、 Figures 7-9 , 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; wherein, 1.0 < (A1 + A2) / (A3 + A4 + A5) < 1.1. In this embodiment, the light rays exit from the display panel 1, are first deflected by the prism assembly 2, and then sequentially pass through the fifth lens 35 to the first lens 31, and finally exit.

[0081] Specifically, through the ratio design of A1 + A2 and A3 + A4 + A5, the balance between the strong convergence ability and the aberration correction ability of the projection lens 3 is achieved, improving the overall imaging quality.

[0082] Through this constraint, 1.0 < (A1 + A2) / (A3 + A4 + A5) < 1.1, ensuring the coordination between the convergence ability of the projection lens 3 and the optimization of the angle of the light rays incident on the prism. The ratio relationship of this constraint being close to 1 indicates that the gap distribution of the lens group is relatively balanced, which helps to optimize the length of the optical system while ensuring the imaging quality.

[0083] 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 the structural design and also beneficial to reducing the tolerance sensitivity.

[0084] In a further embodiment of the present application, the projection optical machine satisfies: 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.

[0085] In this embodiment, by restricting the proportion of the air gap in the total optical length, it is avoided that the distance between the lens groups is too large, resulting in an overly long system length, while ensuring sufficient gap for aberration correction.

[0086] Through this constraint, 0.1 < (A1 + A2) / L < 0.2, 0.1 < (A3 + A4 + A5) / L < 0.2, indicating that the air gaps between the first lens 31 to the third lens 33 and between the third lens 33 and the prism assembly 2 occupy similar and reasonable proportions in the total optical length. The air gaps between the first lens 31 to the third lens 33 and between the third lens 33 and the prism assembly 2 are evenly distributed, which helps to achieve high performance in a compact design.

[0087] In the embodiment of the present application, the projection optical machine satisfies: 0.45 < h / L < 0.60, wherein, L is the total optical length of the projection optical machine.

[0088] In this embodiment, the optical system of the projection optical machine consists of a display panel 1, a prism assembly 2, and a lens group (such as the first lens 31 to the fifth lens 35). Light rays exit from the display panel 1, pass through the prism assembly 2 and the lens group in sequence, and finally form a projection image. The image height h is specifically: the height of the effective imaging area of the display panel 1. The image height h directly affects the field of view and resolution of the projection image. The total optical length L is specifically: the total optical path length from the display panel 1 to the final imaging plane, which reflects the compactness of the system.

[0089] Among them, a larger image height h can support a larger field of view (FOV), thereby increasing the coverage range of the projection image. A smaller L can achieve a more compact system design, which is suitable for portable or space-constrained application scenarios. Through the constraint, 0.45 < h / L < 0.60, indicating that the image height occupies a relatively large proportion in the total optical length, while avoiding an overly long system length, and achieving a balance between a large field of view and compactness.

[0090] When the projection optical machine is applied to a near-eye display device, through precise design of the ratio of the image height to the total optical length, an imaging effect with a large field of view and high resolution is achieved, while keeping the device compact and enhancing the immersive experience.

[0091] The following provides a detailed introduction to the projection optical machine provided by the embodiment of the present application: Embodiment 1 Based on a 640*480*4μm μLED panel (semi-image height 1.6mm), FOV 25°, combined with different offset distances D of the display panel 1 relative to the projection lens 3, the projection optical engine can achieve different angular deflections of the emitted light. The projection optical engine is applied to a near-eye display device, and the deflection angle of the main light ray of the emitted image in the near-eye display device is the same as the deflection angle of the main light ray emitted by the projection lens 3.

[0092] For example, based on a 640*480*4μm μLED panel (semi-image height 1.6mm), FOV 25°, combined with the offset distance D of the display panel 1 relative to the projection lens 3, the projection optical engine can achieve an angular deflection of 0° to ±10.5° for the emitted light. The total optical length L of the projection optical engine is 13mm, the entrance pupil diameter is 3.7mm, F number = 2.0, EFFL = 7.4mm, and the wavelength settings are: 463:527:635nm = 1:2:1.

[0093] Refer to Figure 4 , the specific parameters of the projection lens 3 are shown in Table 1 below, which includes the radius of curvature, thickness, glass material, and semi-aperture of the lens.

[0094] Table 1:

[0095] Refer to Figure 5 , the MTF diagram corresponding to the projection optical engine of the embodiment of the present application, and the average MTF of each field of view > 0.57 @125lp / mm (Nyquist frequency), and the imaging is good.

[0096] Refer to Figure 6 , the defocus MTF diagram corresponding to the projection optical engine of the embodiment of the present application, and the defocus range with MTF > 0.3 @ 125lp / mm (Nyquist frequency) is greater than 0.018mm, having a large defocus range, which is beneficial to improving the imaging quality.

[0097] In a specific embodiment, based on the above parameter limitations, refer to Figure 7 , when the 0.13″ μLED is actually applied, 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 ray of the projection lens 3 is 0°, and an image height of 3.2mm can be achieved, corresponding to FOV = 25° imaging. At this time, the FOV range of the lens imaging is the area of -12.5° to 12.5°.

[0098] In another specific embodiment, based on the above parameter limitations, refer to Figure 8, when the 0.13″ μLED is actually applied, 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 shifted upward by 1.46 mm in the vertical direction relative to the optical axis of the projection lens 3. The deflection angle of the principal ray of the light emitted by the projection optical machine is 10.5°, the image height is 3.2 mm, corresponding to an imaging with FOV = 25°. At this time, the imaging FOV utilized by the projection lens 3 is in the range of 21° to 46°.

[0099] Embodiment 2 Based on a 640*480*4μm μLED panel (semi-image height 1.6 mm), FOV 25°, combined with different offset distances D of the display panel 1 relative to the projection lens 3, the projection optical machine can achieve different angular deflections of the emitted light. The projection optical machine is applied to a near-eye display device, and the deflection angle of the principal ray of the emitted image in the near-eye display device is the same as the deflection angle of the principal ray emitted by the projection lens 3.

[0100] For example, based on a 640*480*4μm μLED panel (semi-image height 1.6 mm), FOV 25°, combined with the offset distance D of the display panel 1 relative to the projection lens 3, the projection optical machine can achieve an angular deflection of the emitted light in the range of 0° to ±10.5°. The total optical length L of the projection optical machine is 13 mm, the entrance pupil diameter is 3.7 mm, F number = 2.0, EFFL = 7.4 mm, and the wavelength setting is: 463:527:635 nm = 1:2:1.

[0101] Refer to Figure 9 , the specific parameters of the projection lens 3 are shown in Table 2 below, which includes the radius of curvature, thickness, glass material, and semi-aperture of the lens.

[0102] Table 2:

[0103] Refer to Figure 10 , for the MTF diagram corresponding to the projection optical machine in the embodiment of the present application, the average MTF of each field of view > 0.3 @125 lp / mm (Nyquist frequency), and the imaging is good.

[0104] The embodiment of the present application also provides a near-eye display device. The near-eye display device includes the projection optical machine and the waveguide device 4 as described above. The projection optical machine is located in the 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 rays that match the setting position of the display panel 1.

[0105] In this embodiment, the projection optical machine is applied to a near-eye display device. By adjusting the offset distance D between the display panel 1 and the projection lens 3, the deflection angle b of the principal ray of the outgoing 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.

[0106] In one embodiment, 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: 2.5mm < pupil < 4.5mm.

[0107] Specifically, the diaphragm of the projection optical machine is a front diaphragm, located in front of the first lens 31, and the diaphragm size satisfies: 2.5mm < pupil < 4.5mm.

[0108] In this embodiment, the exit pupil diaphragm of the projection optical machine (such as an AR optical machine) and the coupling-in region 41 of the light guiding device (such as an optical waveguide) need to be dimensionally matched to ensure efficient beam coupling. In addition, the diaphragm size deviation will cause aberrations (such as pincushion distortion), and the matching design can minimize the optical distortion and ensure clear images.

[0109] Optionally, the distance d from the first lens 31 to the diaphragm surface satisfies: 0 ≤ d < 2mm.

[0110] The differences between the above embodiments are mainly described. As long as the different optimization features between the embodiments are not contradictory, they can be combined to form a more optimal embodiment. For the sake of brevity, they will not be elaborated here.

[0111] Although some specific embodiments of the present application have been described in detail by way of examples, those skilled in the art should understand that the above examples are only for illustration and not for limiting the scope of the present application. Those skilled in the art should understand that the above embodiments can 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 optical machine, characterized in that, The projection optical machine includes a display panel (1) and a projection lens (3). 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). The projection lens (3) includes a fifth lens (35) with a positive optical power, a fourth lens (34) with a positive optical power, a third lens (33) with a negative optical power, a second lens (32) with a positive optical power, and a first lens (31) with a negative optical power, which are arranged coaxially and in sequence along the light transmission direction. Wherein, the deflection angle b of the principal ray of the light emitted by the projection lens (3) satisfies the following condition: 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 optical machine according to claim 1, 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 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 optical machine 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 optical machine 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 < f1 / f < 5.0; 1.1 < f2 / f < 1.3; -0.7 < f3 / f < -0.6; 1.2 < f4 / f < 2.5; 1 < f5 / f < 2; Wherein, f is the total effective focal length of the projection lens (3).

5. The projection optical machine 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 optical machine according to claim 1, characterized in that, 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; wherein, 1.0 < (A1 + A2) / (A3 + A4 + A5) < 1.

1.

7. The projection optical machine according to claim 6, wherein The projection optical machine satisfies: 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 projection optical machine according to claim 1, wherein The projection optical machine satisfies: 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 includes the projection optical machine and the waveguide device (4) as described in any one of claims 1-8. The projection optical machine is located in the light coupling-in area (41) of the waveguide device (4), and the light coupling-out area (42) of the waveguide device (4) is used to couple out image light rays that match the installation position of the display panel (1).

10. The near-eye display device according to claim 9, characterized in that, 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: 2.5mm < pupil < 4.5mm.

Images