Optical systems based on OLEDoS display chips

Abstract

This invention provides an optical system based on an OLEDoS display chip, comprising: multiple lenses, including a fourth lens to a first lens arranged sequentially from the image source side to the human eye observation side of the optical system, each lens having a first side facing the human eye observation side and a second side facing the image source side; a polarization control component, comprising a first composite film and a second composite film, the first composite film being disposed on the first lens or the second lens, and the second composite film being disposed on a first side of a third lens, the polarization control component being used to control the polarization direction of light; a beam splitter, disposed on a second side of the second lens, the beam splitter being used to transmit at least a portion of the light and reflect at least another portion of the light; and a display component, the display component including an OLEDoS display screen. This invention solves the problem in the prior art that optical systems based on OLEDoS display chips are difficult to simultaneously achieve high resolution and low ghosting.

Description

Technical Field

[0001] This invention relates to the field of optical imaging equipment technology, and more specifically, to an optical system based on an OLEDoS display chip. Background Technology

[0002] To shorten optical dimensions, projection products often employ a folded optical path to achieve light folding, thereby reducing the overall optical length and size of the projection product. This method is known as the "pancake scheme." Due to the folded optical path, reflections within the pancake scheme can cause ghosting issues. Even with current coating technology, including AR (anti-reflective) coatings, lens reflections can still cause ghosting. This phenomenon worsens with the increase in the number of optical lenses, as lens reflections become more frequent due to the longer light path, further increasing ghosting. Furthermore, many existing optical systems use resin lenses, which are subject to stress. The more lenses there are, the greater the stress, causing polarization deviations in the folded optical path, resulting in light leakage and ghosting.

[0003] Therefore, in the pancake design, more lenses mean more reflective surfaces, which intensifies ghosting and limits the number of lenses manufacturers can use. Consequently, manufacturers are now quite restrained in limiting the number of lenses. Currently, pancake designs mostly use Fast-LCD (Fast Liquid Crystal Display) screens. Compared to OLED chips or silicon-based OLED chips, Fast-LCD screens have larger pixel sizes and, due to manufacturing limitations, cannot simultaneously achieve small size and high resolution. Therefore, current pancake designs do not have high resolution requirements for the optical system, typically using only two lenses. This results in a larger optical system size and limited resolution for LCD-based pancake designs, with a PPD (pixel density) typically around 20. The screen-door effect caused by low resolution significantly impacts the user experience of VR-HMD modules.

[0004] In other words, existing optical systems based on OLEDoS display chips suffer from the problem of not being able to achieve both high resolution and low ghosting. Summary of the Invention

[0005] The main objective of this invention is to provide an optical system based on an OLEDoS display chip, so as to solve the problem that it is difficult to achieve both high resolution and low ghosting in existing optical systems based on OLEDoS display chips.

[0006] To achieve the above objectives, the present invention provides an optical system based on an OLEDoS display chip, comprising: a plurality of lenses, including a fourth lens to a first lens arranged sequentially from the image source side to the human eye observation side of the optical system, the lenses having a first side facing the human eye observation side and a second side facing the image source side; a polarization control component, the polarization control component including a first composite film and a second composite film, the first composite film being disposed on the first lens or the second lens, the second composite film being disposed on a first side of a third lens, the polarization control component being used to control the polarization direction of light; a beam splitter, the beam splitter being disposed on a second side of the second lens, the beam splitter being used to transmit at least a portion of the light and reflect at least another portion of the light; and a display component, the display component including an OLEDoS display screen.

[0007] Furthermore, the second composite film from the image source side to the human eye observation side includes: a first polarizer for transmitting first light rays having a first linear polarization direction; and a first waveplate for converting the first light rays into second light rays having a first circular polarization direction.

[0008] Furthermore, the first wave plate is a quarter wave plate.

[0009] Furthermore, it is shown that the original light emitted by the display component is linearly polarized light.

[0010] Furthermore, the original light emitted by the display component is circularly polarized light, and the second composite film also includes a second waveplate, which is disposed on the side of the first polarizer facing the image source, so that the polarization direction of the second light is the same as or opposite to that of the original light.

[0011] Furthermore, both the first and second wave plates are quarter-wave plates, and their fast axes are perpendicular.

[0012] Furthermore, the second composite membrane also includes a first antireflective membrane, which is disposed on the side of the first waveplate facing the human eye observation side.

[0013] Furthermore, the first composite film from the image source side to the human eye observation side includes: a third waveplate, which is used to convert the second light ray into a third light ray with a second linear polarization direction; and a polarizing beam splitter, which is used to reflect the third light ray so that the third light ray first passes through the polarizing beam splitter for a first reflection, then passes through the third waveplate, and then is reflected a second time by the beam splitter before passing through the third waveplate again, thus being converted into a fourth light ray with a third linear polarization direction, and the polarizing beam splitter can transmit the fourth light ray.

[0014] Furthermore, the third waveplate is a quarter waveplate.

[0015] Furthermore, the first composite film also includes a second antireflection film, which is disposed on the side of the third waveplate facing the image source.

[0016] Furthermore, the first composite film also includes a second polarizer, which is used to transmit a fourth ray.

[0017] Furthermore, the first lens has negative optical power, and the first side surface of the first lens is concave.

[0018] Furthermore, the second side surface of the first lens is either convex or flat.

[0019] Furthermore, the second lens has positive optical power, and both the first and second sides of the second lens are convex surfaces.

[0020] Furthermore, the third lens has positive optical power, and the first side surface of the third lens is a plane.

[0021] Furthermore, the fourth lens has positive optical power, the first side of the fourth lens is convex, and the second side of the fourth lens is flat.

[0022] Furthermore, the beam splitter is a semi-transparent and semi-reflective film; and / or the lenses are all aspherical lenses.

[0023] Furthermore, the materials of the multiple lenses are resin materials.

[0024] Furthermore, at least two of the lenses have different Abbe numbers.

[0025] Furthermore, the number of lens sides between the first composite diaphragm and the second composite diaphragm is less than or equal to two.

[0026] Furthermore, at least one of the first side surface of the first lens, the first side surface of the second lens, the second side surface of the third lens, the first side surface of the fourth lens, and the second side surface of the fourth lens is coated with an anti-reflective coating.

[0027] According to the technical solution of this invention, an optical system based on an OLEDoS display chip includes multiple lenses, a polarization control component, a beam splitter, and a display component. The multiple lenses include a fourth lens to a first lens arranged sequentially from the image source side to the human eye observation side of the optical system. Each lens has a first side facing the human eye observation side and a second side facing the image source side. The polarization control component includes a first composite film and a second composite film. The first composite film is disposed on the first lens or the second lens, and the second composite film is disposed on the first side of the third lens. The polarization control component is used to control the polarization direction of light. The beam splitter is disposed on the second side of the second lens and is used to transmit at least a portion of the light and reflect at least another portion of the light. The display component includes an OLEDoS display screen.

[0028] By employing a multi-lens design, especially a four-lens design, the resolution of the optical system is improved to adapt to OLEDoS displays, allowing both chip resolution and optical system resolution to fully leverage their advantages. A beam splitter controls light transmission and reflection, and a folded optical path meets the miniaturization requirements of the optical system. Polarization control components control the polarization state of light, ensuring specific polarization state transitions for light participating in imaging, thereby limiting the propagation of non-imaging light and reducing ghosting. Placing the first and second composite films on different lens sides allows for filtering of light reflected from different lens surfaces, reducing the transmission of non-imaging light and minimizing ghosting. Placing the second composite film on the first side of the third lens controls the polarization state of light from the front of the display component, reducing the rearward propagation of non-imaging light. By placing the first composite film on either the first or second lens, the polarization state of light before reaching the human eye's observation side is further controlled, intercepting non-imaging light and reducing ghosting. Attached Figure Description

[0029] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0030] Figure 1 A schematic diagram of the optical system according to Embodiment 1 of the present invention is shown;

[0031] Figure 2 A schematic diagram of the optical system according to Embodiment 2 of the present invention is shown;

[0032] Figure 3 A schematic diagram of the optical system according to Embodiment 5 of the present invention is shown;

[0033] Figure 4 It shows Figure 3 MTF plot of the optical system in the image;

[0034] Figure 5 It shows Figure 3 MTF defocus plot of the optical system in the image;

[0035] Figure 6 It shows Figure 3 MTF plots of the optical system in the image under different fields of view;

[0036] Figure 7 A schematic diagram of the optical system according to Embodiment Six of the present invention is shown;

[0037] Figure 8 It shows Figure 7 MTF plot of the optical system in the image;

[0038] Figure 9 It shows Figure 7 MTF defocus plot of the optical system in the image;

[0039] Figure 10 It shows Figure 7 MTF plots of the optical system in the image under different fields of view;

[0040] Figure 11 A schematic diagram of the optical system according to Embodiment 7 of the present invention is shown;

[0041] Figure 12 It shows Figure 11 MTF plot of the optical system in the image;

[0042] Figure 13 It shows Figure 11 MTF defocus plot of the optical system in the image;

[0043] Figure 14 It shows Figure 11 MTF plots of the optical system in the image under different fields of view.

[0044] The above figures include the following reference numerals:

[0045] E1, First lens; S1, First side surface of the first lens; S2, Second side surface of the first lens; E2, Second lens; S3, First side surface of the second lens; S4, Second side surface of the second lens; E3, Third lens; S5, First side surface of the third lens; S6, Second side surface of the third lens; E4, Fourth lens; S7, First side surface of the fourth lens; S8, Second side surface of the fourth lens; 10, Polarization control assembly; 11, First composite film; 111, Third waveplate; 112, Polarizing beam splitter; 113, Second antireflection film; 114, Second polarizer; 12, Second composite film; 121, First polarizer; 122, First waveplate; 123, First antireflection film; 124, Second waveplate; 20, Beam splitter; 30, Display assembly; 31, OLEDoS display screen; 32, Third antireflection film; 33, Third polarizer; 34, Fourth waveplate. Detailed Implementation

[0046] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0047] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0048] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.

[0049] To address the problem of achieving both high resolution and low ghosting in existing optical systems based on OLEDoS display chips, this invention provides an optical system based on OLEDoS display chips.

[0050] like Figures 1 to 14 As shown, the optical system based on the OLEDoS display chip includes multiple lenses, a polarization control component 10, a beam splitter 20, and a display component 30. The multiple lenses include a fourth lens to a first lens arranged sequentially from the image source side of the optical system to the human eye observation side. Each lens has a first side facing the human eye observation side and a second side facing the image source side. The polarization control component 10 includes a first composite film 11 and a second composite film 12. The first composite film 11 is disposed on the first lens or the second lens, and the second composite film 12 is disposed on the first side of the third lens. The polarization control component 10 is used to control the polarization direction of light. The beam splitter 20 is disposed on the second side of the second lens. The beam splitter 20 is used to transmit at least a portion of the light and reflect at least another portion of the light. The display component 30 includes an OLEDoS display screen 31.

[0051] By employing a multi-lens design, especially a four-lens design, the resolution of the optical system is improved to match the OLEDoS display 31, allowing both chip resolution and optical system resolution to fully leverage their advantages. A beam splitter 20 controls light transmission or reflection, and a folded optical path meets the miniaturization requirements of the optical system. The polarization state of light is controlled by the polarization control component 10, ensuring that the light participating in imaging undergoes specific polarization state transitions, thereby limiting the propagation of non-imaging light and reducing ghosting in the optical system. By placing the first composite film 11 and the second composite film 12 on different lens sides, light reflected from different lens surfaces can be filtered, reducing the transmission of non-imaging light and minimizing ghosting. Placing the second composite film 12 on the first side of the third lens allows control of the polarization state of light from the front end of the display component 30, reducing the rearward propagation of non-imaging light. By placing the first composite film 11 on the first or second lens, the polarization state of light before reaching the human eye's observation side is controlled again, further intercepting non-imaging light and reducing ghosting.

[0052] The optical system of this application can also fold the optical path, ensuring miniaturization while leaving sufficient back focal distance, so as to realize the built-in assembly of the module.

[0053] Optionally, the first lens has negative optical power, and its first side surface is concave. This helps to increase the field of view and improve viewing comfort for the human eye.

[0054] It should be noted that the normal field of view of the human eye is about 120 degrees. According to engineers' precise calculations, a qualified VR device must have a horizontal field of view of 90 degrees to ensure that users can obtain a high degree of immersion. The optical system of this application can guarantee that it meets the usage requirements.

[0055] Optionally, the second side of the first lens is convex, which will contribute to the FOV, imaging quality, yield, etc. of the optical system.

[0056] Of course, the second side of the first lens can also be set to be a plane, which is beneficial to improve the yield of the film material and reduce the defects caused by the curved surface.

[0057] Optionally, the second lens has positive optical power, and both its first and second side surfaces are convex. The third lens has positive optical power, and its first side surface is flat. The fourth lens has positive optical power, its first side surface is convex, and its second side surface is flat. By controlling the optical power and surface shape of the first to fourth lenses as described above, excessive refraction of edge rays at any lens surface can be avoided, reducing large field-of-view aberrations and providing high-resolution image display. The flat design of one side surface of the lens facilitates the attachment of film materials, improving image quality.

[0058] Optionally, the beam splitter 20 is a semi-transparent and semi-reflective film with a reflectivity greater than or equal to 48% in the visible light band and a transmittance greater than or equal to 48%.

[0059] Optionally, all lenses are aspherical lenses.

[0060] Alternatively, multiple lenses can be made of resin, which helps reduce costs and product weight.

[0061] Optionally, at least two of the lenses may be made of materials with different Abbe numbers. Combinations of materials with different Abbe numbers are beneficial for correcting chromatic aberration, reducing chromatic aberration in the optical system, and improving image quality.

[0062] Optionally, the second lens is made of a low-stress birefringent resin material with a retardation (stress) of less than 10 nm.

[0063] Specifically, the number of lens sides between the first composite diaphragm 11 and the second composite diaphragm 12 is less than or equal to two, which can reduce ghosting caused by unintended optical interface reflections. Since the fewer the number of optical interfaces between the first composite diaphragm 11 and the second composite diaphragm 12, that is, the fewer lenses contained in the middle, the better the ghosting situation, reducing stray light while ensuring a certain folding size.

[0064] Optionally, at least one of the first side surface of the first lens, the first side surface of the second lens, the second side surface of the third lens, the first side surface of the fourth lens, and the second side surface of the fourth lens is coated with an anti-reflective coating, which helps to reduce stray light reflected from the lens surface that causes ghosting.

[0065] Optionally, the thickness of the first composite membrane 11 is less than 0.3 mm.

[0066] Optionally, the display component 30 also includes a third antireflection film 32 and a third polarizer 33 to ensure brightness while maintaining the polarization direction of the original light.

[0067] Example 1

[0068] like Figure 1 As shown, the original light emitted from the display component 30 is linearly polarized light.

[0069] like Figure 1 As shown, the second composite film 12 includes a first polarizer 121 and a first waveplate 122 from the image source side to the human eye observation side. The first polarizer 121 is used to transmit a first light ray with a first linear polarization direction; the first waveplate 122 is used to convert the first light ray into a second light ray with a first circular polarization direction. Preferably, the first waveplate is a 1 / 4 waveplate.

[0070] The linearly polarized light emitted from the display component 30 is first converted into a first ray with a first linear polarization direction by the first polarizer 121, and then the first ray is converted into a second ray with a first circular polarization direction by the first waveplate 122 before propagating backward. In other words, when the original light reaches the second composite film 12, due to reflections on the lens surfaces and polarization deviations caused by stress after passing through the fourth and third lenses, the risk of ghosting is greatly increased. However, the transmission and conversion of light with specific polarization states by the first polarizer 121 and the first waveplate 122 intercepts invalid light and reduces the risk of ghosting.

[0071] By setting the second composite diaphragm 12 to select the polarization state of light, reflected light and light with unintended polarization from the third lens, fourth lens, and image source can be blocked from entering the first and second lenses, effectively reducing the ghost image intensity of the optical system. Simultaneously, it can effectively reduce the surface coating requirements for the third and fourth lenses; increase the range of materials that can be selected for the third and fourth lenses, providing greater design freedom, reducing manufacturing difficulty, minimizing chromatic aberration in the optical system, and improving image quality.

[0072] Optionally, the second composite diaphragm 12 further includes a first antireflective film 123, which is disposed on the side of the first waveplate 122 facing the human eye. By providing the first antireflective film 123, the light transmittance can be improved, thereby increasing the brightness of the optical system.

[0073] In this embodiment, the first composite diaphragm 11 is attached to the second side of the first lens.

[0074] like Figure 1 As shown, the first composite film 11 includes a third waveplate 111 and a polarizing beam splitter 112 from the image source side to the human eye observation side. The third waveplate 111 is used to convert the second light ray into a third light ray with a second linear polarization direction. The polarizing beam splitter 112 is used to reflect the third light ray, so that the third light ray first passes through the polarizing beam splitter 112 for a first reflection, then passes through the third waveplate 111, and then is reflected a second time by the beam splitter 20 before passing through the third waveplate 111 again, thus being converted into a fourth light ray with a third linear polarization direction. The polarizing beam splitter 112 can transmit the fourth light ray. Preferably, the third waveplate is a quarter waveplate.

[0075] In other words, the second light ray emitted from the second composite diaphragm 12, which effectively participates in imaging, is transmitted sequentially through the beam splitter 20 and the second lens before reaching the first composite diaphragm 11. It is then transmitted through the third waveplate 111 and reflected by the polarizing beam splitter 112. After passing through the third waveplate 111 and the second lens again, it is reflected upon reaching the beam splitter 20, then transmitted again through the second lens and the third waveplate 111, and finally transmitted again upon reaching the polarizing beam splitter 112. Thus, the light path is folded through the transmission and reflection of the beam splitter 20 and the polarizing beam splitter 112, ensuring that only light rays with a specific polarization state are ultimately transmitted through the polarizing beam splitter 112.

[0076] The following describes the change in the polarization state of light starting with the second light ray emitted from the second composite diaphragm 12, which has a first circular polarization direction. When the second light ray with the first circular polarization direction first passes through the third wave plate 111, it is transformed into a third light ray with a second linear polarization direction. The third light ray is reflected once by the polarizing beam splitter 112 without changing its polarization state. When it passes through the third wave plate 111 again, it changes from the second linear polarization direction to the first circular polarization direction. After being reflected by the polarizing beam splitter 112, the first circular polarization direction changes to the fourth circular polarization direction. When it is transmitted through the third wave plate 111 again, the fourth circular polarization direction changes to the third linear polarization direction. At this time, the fourth light ray with the third linear polarization direction can pass through the polarizing beam splitter 112.

[0077] like Figure 1 As shown, the first composite film 11 also includes a second antireflective film 113, which is disposed on the side of the third waveplate 111 facing the image source. The second antireflective film 113 helps to increase light transmittance and improve brightness.

[0078] like Figure 1 As shown, the first composite film 11 also includes a second polarizer 114, which is used to transmit the fourth light. By setting the second polarizer 114, the polarization state of the light emitted to the human eye observation side is further controlled, preventing light except for light with a third linear polarization direction from emitting from the first composite film 11, thus reducing the probability of ghosting.

[0079] like Figure 1As shown, in this embodiment, the original light emitted from the display component 30 is vertically polarized S-light. After reaching the first polarizer 121 on the second composite diaphragm 12, the first polarizer 121 can transmit the S-polarized light. At this time, the S-polarized light makes a 45° angle with the fast axis of the first waveplate 122, causing the S-polarized light to be converted into left-handed polarized light after passing through the first waveplate 122. Then, after passing through the beam splitter 20 (the energy of the light becomes 50% of the original light energy after transmission), the second lens, and the third waveplate 111 in the first composite diaphragm 11, the left-handed polarized light is converted into P-polarized light. The polarization direction of the P-polarized light is parallel to the reflection axis of the polarizing beam splitter 112. The reflected light after the P-polarized light is reflected by the polarizing beam splitter 112 makes a -45° angle with the fast axis of the third waveplate 111. In the state of ° angle, the P-polarized light is converted into left-handed polarized light after passing through the third waveplate 111. When the left-handed polarized light passes through the second lens and reaches the beam splitter 20, about 50% of the light is reflected (therefore the energy of the light becomes 25% of the original light energy). After reflection, the left-handed polarized light becomes right-handed polarized light. The right-handed polarized light is converted into P-polarized light after passing through the third waveplate 111 in the first composite film 11. The polarization direction is at an angle of -45° with the fast axis of the third waveplate 111 (the fast axis is 45° counterclockwise). At this time, the polarization direction of the light is consistent with the transmission direction of the polarizing beam splitter 112. The light is consistent with the transmission axis of the polarizing beam splitter 112. Therefore, the P-polarized light can pass through the polarizing beam splitter 112 and the second polarizer 114, and finally exit through the first lens.

[0080] In this embodiment, the light emitted from the display component 30 can be reflected within the lens, allowing the light to pass through multiple optical surfaces and be modulated multiple times. Compared to a solution that directly passes through the lens, this embodiment significantly reduces the overall size of the optical system. In this embodiment, the gaps between the components in the optical system are increased, thereby increasing the optical path and shortening the overall length of the optical system.

[0081] Example 2

[0082] like Figure 2 As shown, the difference from Embodiment 1 is that the polarization direction of the original light emitted from the display component 30, the second composite film 12, and the structure of the display component 30 are different.

[0083] Specifically, the original light emitted by the display component 30 is circularly polarized light, and the ellipticity of the original light is >0.95.

[0084] like Figure 2 As shown, the second composite film 12 also includes a second waveplate 124, which is disposed on the side of the first polarizer 121 facing the image source side, so that the polarization direction of the second light is the same as or opposite to that of the original light.

[0085] Specifically, both the first waveplate 122 and the second waveplate 124 are quarter-wave plates, and the fast axes of the first waveplate 122 and the second waveplate 124 are perpendicular to each other to satisfy that the polarization directions of the second ray and the original ray are the same or opposite.

[0086] like Figure 2 As shown, in this embodiment, the display component 30 also includes a fourth waveplate 34. The light emitted from the OLEDoS display screen 31 becomes S-polarized light with an angle of -45° with the fast axis of the fourth waveplate 34 after passing through the third polarizer 33. After passing through the fourth waveplate 34, it is converted into left-handed polarized light and emitted. After being transmitted through the fourth lens and the third lens, it reaches the second waveplate 124 in the second composite film 12. The second waveplate 124 converts the left-handed polarized light into P-polarized light. The first polarizer 121 can transmit the P-polarized light. At this time, the angle between the P-polarized light and the fast axis of the first waveplate 122 is -45°, so that the P-polarized light is converted into left-handed polarized light after passing through the first waveplate 122. The optical path thereafter is the same as in Embodiment 1, and will not be described again here.

[0087] Example 3

[0088] In a specific embodiment not shown, the difference from Embodiment 1 is that the first composite diaphragm 11 is attached to the first side of the first lens.

[0089] Example 4

[0090] In a specific embodiment not shown, the difference from Embodiment 1 is that the first composite diaphragm 11 is attached to the first side of the second lens.

[0091] Example 5

[0092] like Figures 3 to 6 The image shows the optical system of Embodiment 5. It should be noted that Embodiments 1 and 2 described above are also applicable to this embodiment.

[0093] like Figure 3 As shown, the optical system, from the human eye observation side to the image source side, includes, in sequence, a first lens E1, a first composite film 11, a second lens E2, a beam splitter 20, a second composite film 12, a third lens E3, a fourth lens E4, and a display component 30. The first composite film 11 is attached to the second side of the first lens, the beam splitter 20 is attached to the second side of the second lens, and the second composite film 12 is attached to the first side of the third lens.

[0094] The optical system has a focal length of f, a maximum field of view of FOV, and a total length of TTL (from the first side of the first lens to the image source surface). Its values ​​are as follows: f = 15.34 ± 1 mm; FOV = 95° ± 1°; TTL = 19.8 ± 1 mm. The display assembly 30 includes a 1.3-inch OLEDoS display screen 31 with an image plane length of 24.2 mm.

[0095] like Figure 3 As shown, the first side surface of the first lens is S1, the second side surface of the first lens is S2, the first side surface of the second lens is S3, the second side surface of the second lens is S4, the first side surface of the third lens is S5, the second side surface of the third lens is S6, the first side surface of the fourth lens is S7, and the second side surface of the fourth lens is S8.

[0096] Table 1 shows the basic structural parameters of the optical system in this embodiment, where the units for radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0097]

[0098]

[0099] Table 1

[0100] It should be noted that in this embodiment, the radius of curvature of the second side surface of the third lens is actually a large positive number. However, for the sake of convenience, the radius of curvature of the second side surface of the third lens is infinite in Table 1. In reality, the second side surface of the third lens is not a plane, but a convex surface.

[0101] In this embodiment, the first side surface of the first lens, the first side surface and the second side surface of the second lens, the second side surface of the third lens, and the first side surface of the fourth lens are all aspherical surfaces. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0102]

[0103] Where X represents the aspherical sag, which is a function of the coordinate position Y, and Y is the radial distance about the origin. R is the radius of curvature, k is the quadratic surface constant (conic coefficient), i represents the order, and A... i These are the aspheric coefficients for the corresponding order. X, Y, and R are in millimeters (mm), and k, i, and A are in the same unit. i Dimensionless. In the formula (Y) 2 / R) / (1+sqrt(1-(1+k)×(Y / R) 2 The base is a quadratic surface. The offset of the surface relative to the quadratic surface base, when all A iWhen they are all 0, the surface is a pure quadric surface.

[0104] k is the quadric surface constant in the aspheric formula, and its value determines the shape of the quadric surface base. When k = 0, the base is a spherical surface. When -1 < k < 0, the base is an ellipsoid of revolution with the major axis along the optical axis; when k = -1, it is a paraboloid; when k < -1, it is a hyperboloid; when k > 0, it is an ellipsoid generated by rotating an ellipse around its minor axis, and k = e 2 / (1 - e 2 ), where e is the eccentricity of the ellipse.

[0105] Table 2 gives the high-order term coefficients A4, A6, A8, A10, A12, A14, A16 for each aspheric mirror surface in this embodiment.

[0106]

[0107]

[0108] Table 2

[0109] Figure 4 shows the MTF (modulation transfer function) graph of the optical system of Embodiment 5, Figure 5 shows the MTF defocus graph of the optical system of Embodiment 5, Figure 6 shows the MTF graphs of the optical system of Embodiment 5 under different fields of view. In this embodiment, the optical system can provide high-resolution image display, and at 80 lp / mm, MTF > 0.4 can be achieved.

[0110] According to Figures 4 to 6 it can be seen that the optical system given in Embodiment 5 can achieve good imaging quality.

[0111] Embodiment 6

[0112] As Figures 7 to 10 shown, the optical system sequentially includes a first lens E1, a first composite film 11, a second lens E2, a beam splitter film 20, a second composite film 12, a third lens E3, a fourth lens E4, and a display component 30 from the human eye observation side to the image source side. The first composite film 11 is attached to the second side of the first lens, the beam splitter film 20 is attached to the second side of the second lens, and the second composite film 12 is attached to the first side of the third lens.

[0113] Among them, the focal length of the optical system is f, the maximum field of view angle is FOV, and the total length is TTL (from the first side of the first lens to the image source surface). The values are as follows: f = 15.47 ± 1 mm; FOV = 98° ± 1°, TTL = 19.8 ± 1 mm. The display component 30 includes an OLED OS display screen 31 with a size of 1.3 inches and an image plane length of 24.2 mm.

[0114] like Figure 7 As shown, the first side surface of the first lens is S1, the second side surface of the first lens is S2, the first side surface of the second lens is S3, the second side surface of the second lens is S4, the first side surface of the third lens is S5, the second side surface of the third lens is S6, the first side surface of the fourth lens is S7, and the second side surface of the fourth lens is S8.

[0115] Table 3 shows the basic structural parameters of the optical system in this embodiment, where the units for radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0116]

[0117] Table 3

[0118] In this embodiment, the first side surface of the first lens, the first side surface and the second side surface of the second lens, the second side surface of the third lens and the first side surface of the fourth lens are all aspherical surfaces, and the surface shape of each aspherical lens can be defined by, but is not limited to, the formula (1) in Embodiment 5.

[0119] Table 4 provides the higher-order coefficients that can be used for each aspherical mirror in this embodiment.

[0120] Higher-order coefficients / surface S1 S3 S4 S6 S7 k -52.117 56.628 0.198 98.435 1.939 A4 -1.940e-005 -8.301e-007 -5.060e-007 1.044e-006 -8.443e-006 A6 -2.972e-009 -1.486e-008 -4.011e-009 -1.944e-008 -5.211e-008 A8 -2.103e-011 3.776e-011 1.187e-011 -4.523e-011 3.676e-010 A10 -1.043e-013 -1.236e-013 -1.526e-014 1.383e-013 -6.511e-013 A12 -1.902e-016 5.528e-017 -2.863e-017 -7.848e-017 2.503e-016 A14 1.319e-018 / 5.661e-020 6.001e-021 -4.293e-019 A16 -8.870e-021 / 2.931e-023 2.810e-023 -4.364e-021

[0121] Table 4

[0122] Figure 8 The MTF (modulation transfer function) diagram of the optical system in Embodiment Six is ​​shown. Figure 9 The MTF defocus plot of the optical system of Embodiment Six is ​​shown. Figure 10 MTF plots of the optical system of Embodiment Six are shown under different fields of view. In this embodiment, the optical system can provide high-resolution image display, achieving an MTF > 0.4 at 80 lp / mm.

[0123] according to Figures 8 to 10 As can be seen, the optical system given in Example 6 can achieve good imaging quality.

[0124] Example 7

[0125] like Figures 11 to 14 As shown, the optical system, from the human eye observation side to the image source side, includes, in sequence, a first lens E1, a first composite film 11, a second lens E2, a beam splitter 20, a second composite film 12, a third lens E3, a fourth lens E4, and a display component 30. The first composite film 11 is attached to the second side of the first lens, the beam splitter 20 is attached to the second side of the second lens, and the second composite film 12 is attached to the first side of the third lens.

[0126] The optical system has a focal length of f, a maximum field of view (FOV), and a total length of TTL (from the first side of the first lens to the image source surface). These values ​​are as follows: f = 14.155 ± 1 mm; FOV = 106° ± 1°; TTL = 18.25 ± 1 mm. The display assembly 30 includes a 1.3-inch OLEDoS display screen 31 with an image plane length of 24.2 mm.

[0127] like Figure 11 As shown, the first side surface of the first lens is S1, the second side surface of the first lens is S2, the first side surface of the second lens is S3, the second side surface of the second lens is S4, the first side surface of the third lens is S5, the second side surface of the third lens is S6, the first side surface of the fourth lens is S7, and the second side surface of the fourth lens is S8.

[0128] Table 5 shows the basic structural parameters of the optical system in this embodiment, where the units for radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0129]

[0130]

[0131] Table 5

[0132] In this embodiment, the first and second side surfaces of the first lens, the first and second side surfaces of the second lens, the second side surface of the third lens, and the first side surface of the fourth lens are all aspherical. The surface shape of each aspherical lens can be defined by, but is not limited to, the formula (1) in Embodiment 5.

[0133] Table 6 provides the higher-order coefficients that can be used for each aspherical mirror in this embodiment.

[0134] Higher-order coefficients / surface S1 S2 S3 S4 S6 S7 k 11.707 7.943E+00 1.611E+01 8.944E-01 2.094E+01 9.809E+00 A4 -7.381e-005 -2.812E-05 -1.373E-05 -1.092E-05 9.325E-06 3.572E-05 A6 -8.178e-008 4.893E-08 5.724E-09 1.627E-09 -4.190E-08 -1.558E-07 A8 4.244e-010 1.028E-10 1.908E-11 6.398E-13 -6.446E-11 5.905E-10 A10 -3.425e-012 -3.258E-13 3.309E-14 1.010E-13 2.378E-13 -9.168E-13 A12 -5.174e-015 -3.916E-16 2.630E-17 -4.638E-16 / / A14 5.887e-017 / / -1.123E-18 / / A16 4.108e-020 / / / / /

[0135] Table 6

[0136] Figure 12 The MTF (modulation transfer function) diagram of the optical system in Embodiment 7 is shown. Figure 13 The MTF defocus plot of the optical system of Embodiment Seven is shown. Figure 14 MTF plots of the optical system of Embodiment Seven are shown under different fields of view. In this embodiment, the optical system can provide high-resolution image display, achieving an MTF > 0.4 at 80 lp / mm.

[0137] according to Figures 12 to 14 It can be seen that the optical system given in Example 7 can achieve good imaging quality.

[0138] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0139] 1. By adopting a multi-lens design, especially a four-lens design, the resolution of the optical system is improved to match the OLEDoS display 31, allowing the chip resolution and the resolution of the optical system to fully leverage their advantages.

[0140] 2. The beam splitter 20 is used to control the transmission or reflection of light, and the folded optical path meets the miniaturization requirements of the optical system.

[0141] 3. By controlling the polarization state of light through the polarization control component 10, the light participating in imaging has a specific polarization state conversion, thereby limiting the propagation of non-imaging light and reducing the ghosting of the optical system.

[0142] 4. By setting the first composite diaphragm 11 and the second composite diaphragm 12 on different lens sides, the light reflected from different lens surfaces can be filtered, thereby reducing the transmission of non-imaging light and reducing ghosting.

[0143] 5. The second composite film 12 is disposed on the first side of the third lens, which can control the polarization state of the front light from the display component 30 and reduce the propagation of non-imaging light to the rear.

[0144] 6. By setting the first composite diaphragm 11 on the first lens or the second lens, the polarization state of the light before it reaches the human eye observation side is controlled again, further blocking non-imaging light and reducing ghost images.

[0145] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0146] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0147] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0148] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An optical system based on an OLEDoS display chip, characterized in that, include: A plurality of lenses, the plurality of lenses including a fourth to a first lens arranged sequentially from the image source side to the human eye observation side of the optical system, the lenses having a first side facing the human eye observation side and a second side facing the image source side; A polarization control component (10) includes a first composite diaphragm (11) and a second composite diaphragm (12). The first composite diaphragm (11) is disposed on the first lens or the second lens, and the second composite diaphragm (12) is disposed on the first side of the third lens. The polarization control component (10) is used to control the polarization direction of light. Beam splitter (20), the beam splitter (20) is disposed on the second side of the second lens, the beam splitter (20) is used to transmit at least a portion of the light and reflect at least another portion of the light; Display component (30), the display component (30) including OLEDoS display (31).

2. The optical system based on an OLEDoS display chip according to claim 1, characterized in that, The second composite membrane (12) from the image source side to the human eye observation side includes: A first polarizer (121) is used to transmit a first ray having a first linear polarization direction; A first waveplate (122) is used to convert the first ray into a second ray having a first circular polarization direction.

3. The optical system based on an OLEDoS display chip according to claim 2, characterized in that, The first waveplate (122) is a quarter waveplate.

4. The optical system based on an OLEDoS display chip according to claim 2, characterized in that, The original light emitted by the display component (30) is linearly polarized light.

5. The optical system based on an OLEDoS display chip according to claim 2, characterized in that, The original light emitted from the display component (30) is circularly polarized light. The second composite film (12) also includes a second wave plate (124), which is disposed on the side of the first polarizer (121) facing the image source, so that the polarization direction of the second light is the same or opposite to that of the original light.

6. The optical system based on an OLEDoS display chip according to claim 5, characterized in that, Both the first waveplate (122) and the second waveplate (124) are quarter-wave plates, and the fast axes of the first waveplate (122) and the second waveplate (124) are perpendicular.

7. The optical system based on an OLEDoS display chip according to claim 2, characterized in that, The second composite membrane (12) also includes a first antireflective membrane (123), which is disposed on the side of the first waveplate (122) facing the human eye observation side.

8. The optical system based on an OLEDoS display chip according to claim 2, characterized in that, The first composite membrane (11) from the image source side to the human eye observation side includes: A third waveplate (111) is used to convert the second ray into a third ray having a second linear polarization direction; A polarizing beam splitter (112) is used to reflect a third ray so that the third ray is first reflected by the polarizing beam splitter (112), then by the third waveplate (111), and then reflected a second time by the beam splitter (20) and then by the third waveplate (111) again, and is transformed into a fourth ray with a third linear polarization direction. The polarizing beam splitter (112) can transmit the fourth ray.

9. The optical system based on an OLEDoS display chip according to claim 8, characterized in that, The third waveplate (111) is a 1 / 4 waveplate.

10. The optical system based on an OLEDoS display chip according to claim 8, characterized in that, The first composite film (11) also includes a second antireflection film (113), which is disposed on the side of the third waveplate (111) facing the image source.

11. The optical system based on an OLEDoS display chip according to claim 8, characterized in that, The first composite film (11) further includes a second polarizer (114) for transmitting the fourth light.

12. The optical system based on an OLEDoS display chip according to any one of claims 1 to 11, characterized in that, The first lens has negative optical power, and the first side surface of the first lens is concave.

13. The optical system based on an OLEDoS display chip according to claim 12, characterized in that, The second side surface of the first lens is either convex or flat.

14. The optical system based on an OLEDoS display chip according to any one of claims 1 to 11, characterized in that, The second lens has positive optical power, and both the first and second sides of the second lens are convex surfaces.

15. The optical system based on an OLEDoS display chip according to any one of claims 1 to 11, characterized in that, The third lens has positive optical power, and the first side surface of the third lens is a plane.

16. The optical system based on an OLEDoS display chip according to any one of claims 1 to 11, characterized in that, The fourth lens has positive optical power, the first side of the fourth lens is convex, and the second side of the fourth lens is flat.

17. The optical system based on an OLEDoS display chip according to any one of claims 1 to 11, characterized in that, The spectrophotometer (20) is a semi-transparent and semi-reflective membrane; and / or All the lenses are aspherical lenses.

18. The optical system based on an OLEDoS display chip according to any one of claims 1 to 11, characterized in that, The multiple lenses are made of resin.

19. The optical system based on an OLEDoS display chip according to any one of claims 1 to 11, characterized in that, At least two of the plurality of lenses are made of materials with different Abbe numbers.

20. The optical system based on an OLEDoS display chip according to any one of claims 1 to 11, characterized in that, The number of the lens sides between the first composite diaphragm (11) and the second composite diaphragm (12) is less than or equal to two.

21. The optical system based on an OLEDoS display chip according to any one of claims 1 to 11, characterized in that, At least one of the first side surface of the first lens, the first side surface of the second lens, the second side surface of the third lens, the first side surface of the fourth lens, and the second side surface of the fourth lens is coated with an anti-reflective coating.

Images