Eyepiece optical system and mass production manufacturing method thereof

Abstract

An eyepiece optical system is configured to allow imaging light from a display frame to enter an eye of an observer through the eyepiece optical system to form an image. The eyepiece optical system sequentially comprises a first optical element and a second optical element from the eye side to the display side along an optical axis, and each of the first optical element and the second optical element comprises an eye side surface and a display side surface. The eyepiece optical system further comprises a reflective polarizing film and a quarter-wave plate. The eye side surface of the first optical element and the display side surface of the first optical element satisfy the following conditional expression: PV < = 160 [mu] m, wherein PV is a peak-valley value of a surface. In addition, the invention also provides a mass production manufacturing method of the eyepiece optical system.

Description

Technical Field

[0001] The present invention relates to an optical system and a manufacturing method thereof, and in particular to an eyepiece optical system and a mass production method thereof. Background Art

[0002] The eyepiece optical systems currently used in VR on the market can be mainly divided into three categories: aspherical optical elements, Fresnel optical elements and pancake optical elements. The advantages of aspherical optical elements are low manufacturing costs and fewer stray light problems such as flare and ghost, but they are heavy and large in size. The advantages of Fresnel optical elements are light weight and improved half-viewing angle. The manufacturing cost is about twice that of aspherical optical elements, and the disadvantage is that there is a more serious flare problem. The advantage of pancake optical elements is that the weight and volume can be less than half of aspherical optical elements, and there is no flare problem. However, since the cost of optical film materials is half of the cost of the lens, and the film application process and assembly adjustment are more difficult, the manufacturing cost is about 10 to 40 times that of aspherical optical elements and is prone to ghosting problems.

[0003] VR cannot be as popular as smartphones due to the weight, volume, stray light and manufacturing cost issues of the three mainstream optical components. In addition, users of VR systems not only pursue good image quality, but also seek a larger magnification. Therefore, how the industry can design an eyepiece optical system with a lower manufacturing cost, image quality that meets consumer needs and a larger magnification is a challenge that needs to be solved. Summary of the invention

[0004] The present invention provides an eyepiece optical system and a mass production method thereof, which has a low manufacturing cost and meets consumers' demands for image quality and magnification.

[0005] The present invention provides an eyepiece optical system, which is configured to allow imaging light from a display screen to pass through the eyepiece optical system and enter an eye of an observer to form an image, wherein the side facing the eye is an eye side and the side facing the display screen is a display side. The eyepiece optical system includes a first optical element and a second optical element in sequence along an optical axis from the eye side to the display side, and the first optical element and the second optical element each include an eye side surface facing the eye side and allowing the imaging light to pass through and a display side surface facing the display side and allowing the imaging light to pass through. The eyepiece optical system also includes a reflective polarizing film and a quarter-wave plate. The eye side surface of the first optical element and the display side surface of the first optical element satisfy the following conditional formula: PV≤160μm, wherein PV is a peak-to-valley value of a surface. The reflective polarizing film is configured on the eye side of the first optical element. The quarter-wave plate is configured on the display side surface of the first optical element or between the reflective polarizing film and the eye side of the first optical element. The eyepiece optical system satisfies the following conditional formula: 35≤|ObjD| / ImgH≤200, wherein ObjD is the distance from the eye of the observer to the image formed by the eyepiece optical system on the optical axis, and ImgH is the maximum image height of the eyepiece optical system.

[0006] The present invention further provides an eyepiece optical system, which is configured to allow imaging light from a display screen to pass through the eyepiece optical system and enter an eye of an observer to form an image, wherein the side facing the eye is an eye side and the side facing the display screen is a display side. The eyepiece optical system includes a first optical element and a second optical element in sequence along an optical axis from the eye side to the display side, and the first optical element and the second optical element each include an eye side surface facing the eye side and allowing the imaging light to pass through and a display side surface facing the display side and allowing the imaging light to pass through. The eyepiece optical system also includes a reflective polarizing film and a quarter-wave plate. The eye side surface of the first optical element, the display side surface of the first optical element, and the eye side surface of the second optical element meet the following conditional formula: PV≤160μm, wherein PV is a peak-to-valley value of a surface. The reflective polarizing film is configured on the eye side of the first optical element. The quarter-wave plate is configured on the display side surface of the first optical element or between the reflective polarizing film and the eye side of the first optical element. There is no air gap between the display side surface of the first optical element and the eye side surface of the second optical element.

[0007] The present invention further provides a mass production method for an eyepiece optical system, comprising: manufacturing a large-sized first optical element with a low-birefringence plastic or glass material, wherein an eye-side surface of the large-sized first optical element and a display side surface of the large-sized first optical element satisfy the following formula: PV≤160μm, wherein PV is the peak-to-valley value of the surface; configuring a large-sized reflective polarizing film on the eye-side surface of the large-sized first optical element, and configuring a large-sized quarter-wavelength plate on the display side surface of the large-sized first optical element or between the large-sized reflective polarizing film and the eye-side surface of the large-sized first optical element to form an optical film on the large-sized first optical element; using an adhesive that matches the refractive index of the large-sized first optical element and the refractive index of multiple second optical elements to bond the second optical elements to the display side surface of the large-sized first optical element to form an aggregate consisting of multiple eyepiece optical systems arranged in an array; cutting the aggregate consisting of the eyepiece optical systems to form separated eyepiece optical systems.

[0008] Based on the above, the beneficial effects of the eyepiece optical system of the embodiment of the present invention are: by satisfying the optical design conditions, the manufacturing cost of the eyepiece optical system is lowered, and the needs of consumers for image quality and magnification are met.

[0009] In order to make the above features and advantages of the present invention more clearly understood, embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 The present invention is a schematic diagram illustrating how imaging light emitted by a display screen enters the eye through the eyepiece optical system.

[0011] Figure 2 It is a schematic diagram illustrating the surface structure of a lens.

[0012] Figure 3 It is a schematic diagram illustrating the concave-convex structure of a lens surface and the intersection of light rays.

[0013] Figure 4 is a schematic diagram illustrating the surface structure of a lens of Example 1.

[0014] Figure 5 is a schematic diagram illustrating the surface structure of a lens of Example 2.

[0015] Figure 6 is a schematic diagram illustrating the surface structure of a lens of Example 3.

[0016] Figure 7 It is a schematic diagram of the eyepiece optical system of the first embodiment of the present invention.

[0017] FIG. 8A to FIG. 8D Graphs showing the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the first embodiment.

[0018] Fig. 9 Detailed optical data and aspheric parameters of the eyepiece optical system of the first embodiment of the present invention are shown.

[0019] Fig.10 FIG. 4 is a schematic diagram of an eyepiece optical system according to a second embodiment of the present invention.

[0020] FIG. 11A to FIG. 11D Graphs showing the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the second embodiment.

[0021] Fig.12 Detailed optical data and aspheric parameters of the eyepiece optical system of the second embodiment of the present invention are shown.

[0022] Fig.13 FIG. 4 is a schematic diagram of an eyepiece optical system according to a third embodiment of the present invention.

[0023] FIG. 14A to FIG. 14D Graphs showing the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the third embodiment.

[0024] Fig.15 Detailed optical data and aspheric parameters of the eyepiece optical system of the third embodiment of the present invention are shown.

[0025] Fig.16 FIG. 4 is a schematic diagram of an eyepiece optical system according to a fourth embodiment of the present invention.

[0026] 17A to 17D Graphs showing the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the fourth embodiment.

[0027] Fig.18 Detailed optical data and aspheric parameters of the eyepiece optical system of the fourth embodiment of the present invention are shown.

[0028] Fig.19 FIG. 4 is a schematic diagram of an eyepiece optical system according to a fifth embodiment of the present invention.

[0029] FIG. 20A to FIG. 20D Graphs showing the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the fifth embodiment.

[0030] Fig.21 Detailed optical data and aspheric parameters of the eyepiece optical system of the fifth embodiment of the present invention are shown.

[0031] Fig. 22 FIG. 4 is a schematic diagram of an eyepiece optical system according to a sixth embodiment of the present invention.

[0032] FIG. 23A to FIG. 23DGraphs showing the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the sixth embodiment.

[0033] Fig.24 Detailed optical data and aspheric parameters of the eyepiece optical system of the sixth embodiment of the present invention are shown.

[0034] Fig.25 FIG. 4 is a schematic diagram of an eyepiece optical system according to a seventh embodiment of the present invention.

[0035] FIG. 26A to FIG. 26D Graphs showing the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the seventh embodiment.

[0036] Fig. 27 Detailed optical data and aspheric parameters of the eyepiece optical system of the seventh embodiment of the present invention are shown.

[0037] Fig.28 FIG. 4 is a schematic diagram of an eyepiece optical system according to an eighth embodiment of the present invention.

[0038] FIG. 29A to FIG. 29D Graphs showing the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the eighth embodiment.

[0039] Fig.30 Detailed optical data and aspheric parameters of the eyepiece optical system of the eighth embodiment of the present invention are shown.

[0040] Fig.31 FIG. 4 is a schematic diagram of an eyepiece optical system according to a ninth embodiment of the present invention.

[0041] FIG. 32A to FIG. 32D Graphs showing the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the ninth embodiment.

[0042] Fig.33 Detailed optical data and aspheric parameters of the eyepiece optical system of the ninth embodiment of the present invention are shown.

[0043] Fig.34 FIG. 4 is a schematic diagram of an eyepiece optical system according to a tenth embodiment of the present invention.

[0044] FIG. 35A to FIG. 35D Graphs showing the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the tenth embodiment.

[0045] Fig.36 Detailed optical data and aspheric parameters of the eyepiece optical system of the tenth embodiment of the present invention are shown.

[0046] Fig.37 and Fig.38 The numerical values ​​of the relationship formulas of the important parameters of the eyepiece optical systems of the first to fifth embodiments of the present invention are shown.

[0047] Fig.39 and Fig.40 The numerical values ​​of the relationship formulas of the important parameters of the eyepiece optical systems of the sixth to tenth embodiments of the present invention are shown.

[0048] Fig.41 A flow chart showing the steps of the mass production method of the eyepiece optical system of the present invention.

[0049] Fig.42 A schematic diagram showing a mass production method of the eyepiece optical system of the present invention.

[0050] Description of reference numerals:

[0051] 0: pupil; 1: first optical element; 10, V100: eyepiece optical system;

[0052] 100, 200, 300, 400, 500: lenses; 130: assembly part;

[0053] 15,25,35,45,55,85,110,410,510: side view of the eye;

[0054] 151,161,251,261,351,361,Z1: optical axis area;

[0055] 153,163,253,263,353,363,Z2: circumferential area;

[0056] 16,26,36,46,56,86,120,320: Display side;

[0057] 2: second optical element; 211, 212: parallel light; 3: third optical element; 4: linear polarization film plus reflective polarization film; 5: quarter-wave plate; 6: partial reflector; 7: air gap; 8: optical transparent adhesive;

[0058] 99, V50: display screen; A1: eye side; A2: display side; CP: center point; CP1: first center point; CP2: second center point; EL: extension line; I: optical axis; Lc: principal ray; Lm: marginal ray; M, R: intersection point; OB: optical boundary; TP1: first transition point; TP2: second transition point;

[0059] V60: eye; VD: visual distance; VI: imaging light; VV: magnified virtual image; Z3: relay area. DETAILED DESCRIPTION

[0060] Generally speaking, the light direction of the eyepiece optical system V100 is that an imaging light VI is emitted from the display screen V50, enters the eye V60 through the eyepiece optical system V100, focuses on the retina of the eye V60, and generates an enlarged virtual image VV at the clear vision distance VD, such as Figure 1 The optical specifications of the present invention are described below based on the assumption that the direction of the light is reversely tracked as a parallel imaging light beam from the eye side through the eyepiece optical system to the display screen to form a focused image.

[0061] The terms "optical axis region", "circumferential region", "concave surface" and "convex surface" used in this specification and the claims should be interpreted based on the definitions listed in this specification.

[0062] The optical system of this specification includes at least one lens, which receives the imaging light of the incident optical system that is parallel to the optical axis and within a half-viewing angle (HFOV) relative to the optical axis. The imaging light is imaged on the imaging plane through the optical system. The so-called "a lens having a positive refractive power (or a negative refractive power)" means that the paraxial refractive power of the lens calculated by Gaussian optical theory is positive (or negative). The so-called "eye side (or display side) of the lens" is defined as a specific range where the imaging light passes through the lens surface. The imaging light includes at least two types of light: the chief ray Lc and the marginal ray Lm (such as Figure 2 The eye side (or display side) of the lens can be divided into different areas according to different positions, including an optical axis area, a circumferential area, or one or more relay areas in some embodiments. The description of these areas will be described in detail below.

[0063] Figure 2 is a radial cross-sectional view of the lens 100. Two reference points on the surface of the lens 100 are defined: a center point and a transition point. The center point of the lens surface is an intersection of the surface and the optical axis I. Figure 2 As shown in the example, the first center point CP1 is located on the eye side 110 of the lens 100, and the second center point CP2 is located on the display side 120 of the lens 100. A transition point is a point on the lens surface, and the tangent of the point is perpendicular to the optical axis I. The optical boundary OB of the lens surface is defined as the point where the radially outermost edge ray Lm passing through the lens surface intersects with the lens surface. All transition points are located between the optical axis I and the optical boundary OB of the lens surface. In addition, the surface of the lens 100 may have no transition points or at least one transition point. If a single lens surface has multiple transition points, the transition points are named in sequence from the first transition point in the radial outward direction. For example, the first transition point TP1 (closest to the optical axis I), the second transition point TP2 (closest to the optical axis I), and the second transition point TP2 (closest to the optical axis I). Figure 5 as shown) and the Nth conversion point (farthest from the optical axis I).

[0064] When the lens surface has at least one transition point, the range from the center point to the first transition point TP1 is defined as the optical axis area, wherein the optical axis area includes the center point. The area radially outward from the transition point farthest from the optical axis I (the Nth transition point) to the optical boundary OB is defined as the circumferential area. In some embodiments, a relay area between the optical axis area and the circumferential area may be further included, and the number of relay areas depends on the number of transition points. When the lens surface does not have a transition point, 0% to 50% of the distance from the optical axis I to the optical boundary OB of the lens surface is defined as the optical axis area, and 50% to 100% of the distance from the optical axis I to the optical boundary OB of the lens surface is defined as the circumferential area.

[0065] When a light ray parallel to the optical axis I passes through an area, if the light ray is deflected toward the optical axis I and the intersection with the optical axis I is located at the display side A2 of the lens, then the area is convex. When a light ray parallel to the optical axis I passes through an area, if the intersection of the extended line of the light ray and the optical axis I is located at the eye side A1 of the lens, then the area is concave.

[0066] In addition, see Figure 2 The lens 100 may further include an assembly portion 130 extending radially outward from the optical boundary OB. The assembly portion 130 is generally used for assembling the lens 100 to a corresponding element (not shown) of the optical system. The imaging light does not reach the assembly portion 130. The structure and shape of the assembly portion 130 are merely examples for illustrating the present invention and are not intended to limit the scope of the present invention. The assembly portion 130 of the lens discussed below may be partially or completely omitted in the drawings.

[0067] See also Figure 3 , define the area between the center point CP and the first transition point TP1 as the optical axis area Z1. Define the area between the first transition point TP1 and the optical boundary OB of the lens surface as the circumferential area Z2. Figure 3 As shown, after passing through the optical axis area Z1, the parallel light 211 intersects with the optical axis I at the display side A2 of the lens 200, that is, the focus of the parallel light 211 passing through the optical axis area Z1 is located at point R on the display side A2 of the lens 200. Since the light intersects with the optical axis I at the display side A2 of the lens 200, the optical axis area Z1 is a convex surface. On the contrary, the parallel light 212 diverges after passing through the circumferential area Z2. Figure 3 As shown, the extended line EL of the parallel light 212 after passing through the circumferential area Z2 intersects with the optical axis I at the eye side A1 of the lens 200, that is, the focus of the parallel light 212 passing through the circumferential area Z2 is located at the point M on the eye side A1 of the lens 200. Since the extended line EL of the light intersects with the optical axis I at the eye side A1 of the lens 200, the circumferential area Z2 is a concave surface. Figure 3In the lens 200 shown, the first transition point TP1 is the boundary between the optical axis area and the circumferential area, that is, the first transition point TP1 is the boundary point where the convex surface turns into the concave surface.

[0068] On the other hand, the surface convexity of the optical axis area can also be determined according to the judgment method of the general knowledgeable person in the field, that is, the convexity of the surface shape of the optical axis area of ​​the lens can be determined by the positive and negative signs of the curvature radius of the paraxial axis (abbreviated as R value). R value can be commonly used in optical design software, such as Zemax or CodeV. R value is also commonly found in the lens data sheet of optical design software. For the eye side, when the R value is positive, the optical axis area of ​​the eye side is determined to be convex; when the R value is negative, the optical axis area of ​​the eye side is determined to be concave. On the contrary, for the display side, when the R value is positive, the optical axis area of ​​the display side is determined to be concave; when the R value is negative, the optical axis area of ​​the display side is determined to be convex. The result of this method is consistent with the result of the above-mentioned determination method by the intersection of the light / light extension line and the optical axis. The determination method of the intersection of the light / light extension line and the optical axis is to determine the surface convexity by locating the focus of a light parallel to the optical axis on the eye side or the display side of the lens. The terms “a region is convex (or concave)”, “a region is convex (or concave)” or “a convex (or concave) region” described in this specification can be used interchangeably.

[0069] Figures 4 to 6 Examples are provided for determining the surface shape and area boundaries of lens areas in various situations, including the aforementioned optical axis area, circumferential area, and relay area.

[0070] Figure 4 is a radial cross-sectional view of the lens 300. Figure 4 , the display side surface 320 of the lens 300 has only one transition point TP1 within the optical boundary OB. The optical axis area Z1 and the circumferential area Z2 of the display side surface 320 of the lens 300 are as follows: Figure 4 The R value of the display side surface 320 is positive (ie, R>0), and therefore, the optical axis region Z1 is a concave surface.

[0071] Generally speaking, the shapes of the areas bounded by the conversion point are opposite to those of the adjacent areas. Therefore, the conversion point can be used to define the transition of the surface shape, that is, from concave to convex or from convex to concave. Figure 4 In the figure, since the optical axis area Z1 is a concave surface, the surface shape changes at the transition point TP1, so the circumferential area Z2 is a convex surface.

[0072] Figure 5 is a radial cross-sectional view of the lens 400. Figure 5, there is a first transition point TP1 and a second transition point TP2 on the eye side surface 410 of the lens 400. The area between the optical axis I and the first transition point TP1 is defined as an optical axis region Z1 of the eye side surface 410. The R value of the eye side surface 410 is positive (ie, R>0), and therefore, the optical axis region Z1 is a convex surface.

[0073] The area between the second transition point TP2 and the optical boundary OB of the eye side surface 410 of the lens 400 is defined as a circumferential area Z2, and the circumferential area Z2 of the eye side surface 410 is also a convex surface. In addition, the area between the first transition point TP1 and the second transition point TP2 is defined as a relay area Z3, and the relay area Z3 of the eye side surface 410 is a concave surface. Figure 5 The eye-side surface 410 includes, radially outward from the optical axis I, an optical axis region Z1 between the optical axis I and the first conversion point TP1, a relay region Z3 between the first conversion point TP1 and the second conversion point TP2, and a circumferential region Z2 between the second conversion point TP2 and the optical boundary OB of the eye-side surface 410 of the lens 400. Since the optical axis region Z1 is a convex surface, the surface shape changes from the first conversion point TP1 to a concave surface, so the relay region Z3 is a concave surface, and the surface shape changes from the second conversion point TP2 to a convex surface, so the circumferential region Z2 is a convex surface.

[0074] Figure 6 is a radial cross-sectional view of the lens 500. The eye side surface 510 of the lens 500 has no transition point. For a lens surface without a transition point, such as the eye side surface 510 of the lens 500, 0% to 50% of the distance from the optical axis I to the optical boundary OB of the lens surface is defined as the optical axis area, and 50% to 100% of the distance from the optical axis I to the optical boundary OB of the lens surface is defined as the circumferential area. Figure 6 The lens 500 shown in the figure defines the optical axis region Z1 of the eye side surface 510 as 50% of the distance from the optical axis I to the optical boundary OB of the lens 500 surface. The R value of the eye side surface 510 is positive (i.e., R>0), so the optical axis region Z1 is a convex surface. Since the eye side surface 510 of the lens 500 has no transition point, the circumferential region Z2 of the eye side surface 510 is also a convex surface. The lens 500 may further have an assembly portion (not shown) extending radially outward from the circumferential region Z2.

[0075] Figure 7 It is a schematic diagram of the eyepiece optical system of the first embodiment of the present invention. FIG. 8A to FIG. 8D The longitudinal spherical aberration and various aberration diagrams of the eyepiece optical system of the first embodiment. Figure 7 The eyepiece optical system 10 of the first embodiment of the present invention includes a linear polarizing film plus a reflective polarizing film 4, a first optical element 1, a quarter-wave plate 5 and a second optical element 2 in sequence from the eye side A1 to the display side A2 along an optical axis I of the eyepiece optical system 10. Figure 7 The light emitted by the display screen 99 shown in the figure enters an eye (such as Figure 7 The pupil 0) of the observer shown forms an image, and this image is a magnified virtual image.

[0076] In this embodiment, the first optical element 1, the second optical element 2, the polarizing film plus the reflective polarizing film 4, and the quarter-wave plate 5 each have an eye side surface 15, 25, 45, 55 facing the eye side A1 and allowing the imaging light to pass through, and a display side surface 16, 26, 46, 56 facing the display side A2 and allowing the imaging light to pass through. In this embodiment, the first optical element 1 is placed between the pupil 0 and the second optical element 2. In addition, the display side surface 26 of the second optical element 2 includes a partial reflector 6 for reflecting part of the energy of the imaging light. The partial reflector 6 has an average optical reflectivity of at least 30% in a desired plurality of wavelengths, and in this embodiment, the partial reflector 6 is a half reflector.

[0077] The first optical element 1 is a flat plate. The optical axis region 151 of the eye side surface 15 of the first optical element 1 is a plane, and its circumferential region 153 is a plane. The optical axis region 161 of the display side surface 16 of the first optical element 1 is a plane, and its circumferential region 163 is a plane.

[0078] The second optical element 2 is a lens and has a positive refractive power. The optical axis region 251 of the eye side surface 25 of the second optical element 2 is a plane, and its circumferential region 253 is a plane. The optical axis region 261 of the display side surface 26 of the second optical element 2 is a convex surface, and its circumferential region 263 is a convex surface. In the present embodiment, the eye side surface 25 and the display side surface 26 of the second optical element 2 are both aspherical surfaces, but the present invention is not limited thereto. The peak-to-valley values ​​of the eye side surface 15 of the first optical element 1, the display side surface 16 of the first optical element 1, and the eye side surface 25 of the second optical element 2 satisfy PV=0μm. However, in practice, the peak-to-valley values ​​are affected by the tolerances generated during the manufacturing process, resulting in PV≤5μm.

[0079] The reflective polarizing film is disposed on the eye side A1 of the first optical element 1 to reflect imaging light with one linear polarization state and allow imaging light with another linear polarization state to pass. Specifically, the linear polarizing film plus the reflective polarizing film 4 is disposed on the eye side 15 of the first optical element 1 .

[0080] The quarter-wave plate 5 is disposed between the display side A2 of the first optical element 1 or the linear polarization film plus the reflective polarization film 4 and the eye side A1 of the first optical element 1 to convert the imaging light in the circular polarization state into the imaging light in the linear polarization state, or convert the imaging light in the linear polarization state into the imaging light in the circular polarization state. Specifically, the quarter-wave plate 5 is disposed between the display side surface 16 of the first optical element 1 and the eye side surface 25 of the second optical element 2.

[0081] Specifically, in this embodiment, the display screen (such as Figure 7 The display screen 99 shown provides imaging light with one of the circular polarization states, which passes through the second optical element 2 to the quarter-wave plate 5 to form imaging light with one of the linear polarization states. The imaging light with one of the linear polarization states passes through the first optical element 1 to the reflective polarizing film to reflect the imaging light with one of the linear polarization states. The imaging light with one of the linear polarization states passes through the first optical element 1 and the quarter-wave plate 5 again to form imaging light with the other circular polarization state. The imaging light with the other circular polarization state passes through the second optical element 2 to the display side 26 of the second optical element 2 including a partial reflector 6 to reflect the imaging light with the other circular polarization state. The imaging light with the other circular polarization state passes through the second optical element 2 to the quarter-wave plate 5 again to form imaging light with the other linear polarization state. Finally, the imaging light with the other linear polarization state passes through the first optical element 1 and the linear polarization film plus the reflective polarizing film 4 and enters the observer's eyes (such as Figure 7 The observer's pupil 0) is shown to form the image.

[0082] Other detailed optical data of the first embodiment are as follows Fig. 9 As shown, the effective focal length (EFL) of the eyepiece optical system 10 of the first embodiment is 23.906 mm, the half field of view (HFOV) is 45.000 degrees, the TTL is 21.685 mm, the aperture value (F-number, Fno) is 5.976, and the image height is 17.196 mm, wherein TTL refers to the distance from the eye side surface 15 of the first optical element 1 to the display screen 99 on the optical axis I.

[0083] In addition, in this embodiment, the display side surface 26 of the second optical element 2 is an aspherical surface, wherein the display side surface 26 is a general even asphere surface. These aspherical surfaces are defined according to the following formula (1):

[0084]

[0085] in:

[0086] R: radius of curvature of the lens surface at the near optical axis I;

[0087] Z: Depth of the aspherical surface (the vertical distance between the point on the aspherical surface that is Y away from the optical axis I and the tangent plane that is tangent to the vertex on the aspherical optical axis I);

[0088] Y: the vertical distance between the point on the aspheric curve and the optical axis I;

[0089] K: conic constant;

[0090] a i : i-th order aspheric coefficient.

[0091] The aspheric coefficients of the display side surface 26 of the second optical element 2 in formula (1) are as follows: Fig. 9 As shown. Among them, Fig. 9 The column number 26 in the middle represents the aspheric coefficient of the display side surface 26 of the second optical element 2, and the other columns are similar. In this embodiment and the following embodiments, the second-order aspheric coefficient a2 is 0.

[0092] In addition, the relationship between the important parameters of the eyepiece optical system 10 of the first embodiment is as follows: Fig.37 and Fig.38 shown.

[0093] in,

[0094] EPD is the exit pupil diameter of the eyepiece optical system 10, corresponding to the diameter of the pupil 0 of the observer;

[0095] ER is the exit pupil distance, i.e., the distance from the pupil 0 of the observer to the first optical element 1 on the optical axis I;

[0096] ER11 is the maximum distance from the center of the eye side surface 15 of the first optical element 1 to the mounting portion;

[0097] ER12 is the maximum distance from the center of the display side surface 16 of the first optical element 1 to the mounting portion;

[0098] ER21 is the maximum distance from the center of the object-side surface 25 of the second optical element 2 to the mounting portion;

[0099] ER22 is the maximum distance from the center of the display side surface 26 of the second optical element 2 to the mounting portion;

[0100] PV is the peak-to-valley value of the surface, in other words, the difference between the highest point and the lowest point of the surface;

[0101] ω is the half visual angle, i.e. the maximum angle of half the observer’s visual field;

[0102] ObjH is the maximum height of the image formed in the eyepiece optical system 10, and this image is a virtual image;

[0103] ObjD is the distance from the pupil 0 of the observer to the image formed by the eyepiece optical system 10 on the optical axis I;

[0104] T1 is the thickness of the first optical element 1 on the optical axis I;

[0105] T2 is the thickness of the second optical element 2 on the optical axis I;

[0106] Tlp+Trp is the sum of the thickness of the linear polarizing film and the reflective polarizing film 4 on the optical axis I;

[0107] Tqwp is the thickness of the quarter-wave plate 5 on the optical axis I;

[0108] Toca is the thickness of the optically transparent adhesive 8 on the optical axis I;

[0109] G12 is the air gap 7 between the first optical element 1 and the second optical element 2 on the optical axis I;

[0110] BFL is the distance from the display side surface 26 of the second optical element 2 to the display screen 99 on the optical axis I;

[0111] ImgH is the maximum image height of the eyepiece optical system 10, which is half the diameter of the image circle;

[0112] ALT is the sum of the thicknesses of the first optical element 1 and the second optical element 2 on the optical axis I;

[0113] TL is the distance from the eye side of the optical element closest to the eye side A1 to the display side 26 of the second optical element 2 on the optical axis I;

[0114] TTL is the distance from the eye side of the optical element closest to the eye side A1 to the display screen 99 on the optical axis I;

[0115] SL is the system length of the eyepiece optical system 10, that is, the distance from the observer's eye to the display screen 99 on the optical axis I;

[0116] EFL is the effective focal length of the eyepiece optical system 10 .

[0117] In addition, define:

[0118] f1 is the focal length of the first optical element 1;

[0119] f2 is the focal length of the second optical element 2;

[0120] f3 is the focal length of the third optical element 3;

[0121] Nd1 is the refractive index of the first optical element 1;

[0122] Nd2 is the refractive index of the second optical element 2;

[0123] Nd3 is the refractive index of the third optical element 3;

[0124] V1 is the Abbe number of the first optical element 1;

[0125] V2 is the Abbe number of the second optical element 2;

[0126] V3 is the Abbe number of the third optical element 3 .

[0127] Also refer to FIG. 8A to FIG. 8D , Fig. 8A The diagram of the first embodiment illustrates the longitudinal spherical aberration (Longitudinal Spherical Aberration) on the display screen 99 when the wavelength is 486nm, 588nm and 656nm. Figure 8B and Figure 8C The figures respectively illustrate the field curvature aberration in the sagittal direction and the field curvature aberration in the tangential direction on the display screen 99 of the first embodiment when the wavelength is 486nm, 588nm and 656nm. Fig.8D The diagrams of FIG. 1 illustrate the distortion aberration of the first embodiment on the display screen 99 when the wavelength is 486 nm, 588 nm and 656 nm. The longitudinal spherical aberration of the first embodiment is shown in FIG. Fig. 8A As shown, the curves formed by each wavelength are very close and close to the middle, indicating that the off-axis light rays of different heights of each wavelength are concentrated near the imaging point. It can be seen from the deflection amplitude of the curve of each wavelength that the imaging point deviation of the off-axis light rays of different heights is controlled within the range of ±0.08 mm. Therefore, the first embodiment does significantly improve the spherical aberration of the same wavelength. In addition, the distances between the three representative wavelengths are also very close to each other, representing that the imaging positions of the light rays of different wavelengths are already very concentrated, thereby significantly improving the chromatic aberration.

[0128] exist Figure 8B and Figure 8C In the two field curvature aberration diagrams, the focal length variation of the three representative wavelengths in the entire field of view falls within ±1.00 mm, indicating that the optical system of the first embodiment can effectively eliminate aberrations. Fig.8DThe distortion diagram shows that the distortion of the present embodiment is maintained within the range of ±30%, indicating that the distortion of the present first embodiment has met the imaging quality requirements of the optical system. This shows that compared with the existing optical system, the present first embodiment can still provide good imaging quality under the condition that the TTL has been shortened to 21.685 mm. Therefore, the present first embodiment can have a larger aperture, a larger image height, excellent imaging quality and a lower manufacturing cost while maintaining good optical performance.

[0129] Fig.10 FIG. 4 is a schematic diagram of an eyepiece optical system according to a second embodiment of the present invention. FIG. 11A to FIG. 11D This is a diagram of the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the second embodiment. Fig.10 The second embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the differences between the two are as follows: the optical data, aspheric coefficients, and parameters between the first optical element 1, the second optical element 2, the linear polarization film plus the reflective polarization film 4, and the quarter-wave plate 5 are more or less different. In addition, in this embodiment, the linear polarization film plus the reflective polarization film 4 is disposed on the quarter-wave plate 5, which is conducive to the superposition of the three optical films. It should be noted here that in order to clearly display the drawing, Fig.10 Part of the numbers of the optical axis area and the circumferential area having a surface shape similar to that of the first embodiment are omitted.

[0130] The detailed optical data of the eyepiece optical system 10 of the second embodiment are as follows: Fig.12 As shown, the effective focal length of the eyepiece optical system 10 of the second embodiment is 23.906 mm, the half viewing angle is 45.000 degrees, the TTL is 21.685 mm, the aperture value is 5.976, and the image height is 17.196 mm.

[0131] Fig.12 The aspheric coefficients of the display side surface 26 of the second optical element 2 of the second embodiment in the above formula (1) are also shown.

[0132] In addition, the relationship between the important parameters in the eyepiece optical system 10 of the second embodiment is as follows: Fig.37 and Fig.38 shown.

[0133] Fig.11A The longitudinal spherical aberration of the second embodiment is shown, and the imaging point deviation of off-axis light rays at different heights is controlled within the range of ±0.08 mm. Fig. 11B and Fig. 11C In the two field curvature aberration diagrams, the focal length variation of the three representative wavelengths in the entire field of view falls within ±1.00 mm. Fig.11D The distortion diagram shows that the distortion of this embodiment is maintained within the range of ±30%.

[0134] It can be seen from the above description that the second embodiment is easy to manufacture. Therefore, compared with the first embodiment, the second embodiment has a higher yield.

[0135] Fig.13 FIG. 4 is a schematic diagram of an eyepiece optical system according to a third embodiment of the present invention. FIG. 14A to FIG. 14D The longitudinal spherical aberration and various aberration diagrams of the eyepiece optical system of the third embodiment. Fig.13 , the third embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the differences between the two are as follows: the optical data, aspheric coefficients and parameters between the first optical element 1, the second optical element 2, the linear polarization film plus the reflective polarization film 4 and the quarter-wave plate 5 are more or less different. In addition, in this embodiment, the material of the first optical element 1 is replaced with a low-birefringence plastic material, which is conducive to the use of low-stress optical plastic materials to reduce the occurrence of ghosting. It should be noted here that in order to clearly display the drawing, Fig.13 Part of the numbers of the optical axis area and the circumferential area having a surface shape similar to that of the first embodiment are omitted.

[0136] The detailed optical data of the eyepiece optical system 10 of the third embodiment are as follows: Fig.15 As shown, the effective focal length of the eyepiece optical system 10 of the third embodiment is 23.920 mm, the half viewing angle is 44.999 degrees, the TTL is 21.609 mm, the aperture value is 5.980, and the image height is 17.204 mm.

[0137] Fig.15 The aspheric coefficients of the display side surface 26 of the second optical element 2 of the third embodiment in the above formula (1) are also shown.

[0138] In addition, the relationship between the important parameters in the eyepiece optical system 10 of the third embodiment is as follows: Fig.37 and Fig.38 shown.

[0139] Fig.14A The longitudinal spherical aberration of the third embodiment is shown, and the imaging point deviation of off-axis light rays at different heights is controlled within the range of ±0.08 mm. Fig. 14B and Fig. 14C In the two field curvature aberration diagrams, the focal length variation of the three representative wavelengths in the entire field of view falls within ±1.00 mm. Fig.14D The distortion diagram shows that the distortion of this embodiment is maintained within the range of ±30%.

[0140] From the above description, it can be known that the TTL of the third embodiment is shorter than the TTL of the first embodiment. Therefore, compared with the first embodiment, the third embodiment has a smaller volume. The image height of the third embodiment is greater than the image height of the first embodiment. Therefore, compared with the first embodiment, the third embodiment has a better sensitivity.

[0141] Fig.16 FIG. 4 is a schematic diagram of an eyepiece optical system according to a fourth embodiment of the present invention. 17A to 17D This is a diagram of the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the fourth embodiment. Fig.16 , the fourth embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the differences between the two are as follows: the optical data, aspheric coefficients and parameters between the first optical element 1, the second optical element 2, the linear polarization film plus the reflective polarization film 4 and the quarter-wave plate 5 are more or less different. In addition, in this embodiment, the material is replaced with a low birefringence glass material, which is conducive to the use of low-stress optical glass materials to reduce the occurrence of ghosting. It should be noted here that in order to clearly display the drawing, Fig.16 Part of the numbers of the optical axis area and the circumferential area having a surface shape similar to that of the first embodiment are omitted.

[0142] The detailed optical data of the eyepiece optical system 10 of the fourth embodiment are as follows: Fig.18 As shown, the effective focal length of the eyepiece optical system 10 of the fourth embodiment is 23.913 mm, the half viewing angle is 44.999 degrees, the TTL is 21.647 mm, the aperture value is 5.978, and the image height is 17.200 mm.

[0143] Fig.18 The aspheric coefficients of the display side surface 26 of the second optical element 2 of the fourth embodiment in the above formula (1) are also shown.

[0144] In addition, the relationship between the important parameters in the eyepiece optical system 10 of the fourth embodiment is as follows: Fig.37 and Fig.38 shown.

[0145] Fig.17A The longitudinal spherical aberration of the fourth embodiment is shown, and the imaging point deviation of off-axis light rays at different heights is controlled within the range of ±0.08 mm. Fig. 17B and Fig. 17C In the two field curvature aberration diagrams, the focal length variation of the three representative wavelengths in the entire field of view falls within ±1.00 mm. Fig.17D The distortion diagram shows that the distortion of this embodiment is maintained within the range of ±30%.

[0146] From the above description, it can be known that the TTL of the fourth embodiment is shorter than that of the first embodiment. Therefore, compared with the first embodiment, the fourth embodiment has a smaller volume. The image height of the fourth embodiment is greater than that of the first embodiment. Therefore, compared with the first embodiment, the fourth embodiment has a better sensitivity. Fig.19 FIG. 4 is a schematic diagram of an eyepiece optical system according to a fifth embodiment of the present invention. FIG. 20A to FIG. 20D The longitudinal spherical aberration and various aberration diagrams of the eyepiece optical system of the fifth embodiment. Fig.19 , the fifth embodiment of the eyepiece optical system 10 of the present invention is roughly similar to the first embodiment, and the differences between the two are as follows: the optical data, aspheric coefficients and parameters between the first optical element 1, the second optical element 2, the linear polarization film plus the reflective polarization film 4 and the quarter-wave plate 5 are more or less different. In addition, in this embodiment, anti-reflection films are designed on the display side 16 of the first optical element 1 and the eye side 25 of the second optical element 2, which is beneficial to reduce the occurrence of ghost images. In addition, there is an air gap 7 between the first optical element 1 and the second optical element 2, which is beneficial to reduce TTL and reduce the difficulty of the bonding process between the first optical element 1 and the second optical element 2. It should be noted here that in order to clearly display the drawings, Fig.19 Part of the numbers of the optical axis area and the circumferential area having a surface shape similar to that of the first embodiment are omitted.

[0147] The detailed optical data of the eyepiece optical system 10 of the fifth embodiment are as follows: Fig.21 As shown, the effective focal length of the eyepiece optical system 10 of the fifth embodiment is 24.259 mm, the half viewing angle is 50.385 degrees, the TTL is 20.968 mm, the aperture value is 6.065, and the image height is 19.120 mm.

[0148] Fig.21 The aspheric coefficients of the display side surface 26 of the second optical element 2 of the fifth embodiment in the above formula (1) are also shown.

[0149] In addition, the relationship between the important parameters in the eyepiece optical system 10 of the fifth embodiment is as follows: Fig.37 and Fig.38 shown.

[0150] Fig. 20A The longitudinal spherical aberration of the fifth embodiment is shown, and the imaging point deviation of off-axis light rays at different heights is controlled within the range of ±0.08 mm. Fig. 20B and Fig. 20C In the two field curvature aberration diagrams, the focal length variation of the three representative wavelengths in the entire field of view falls within ±1.00 mm. Fig.20D The distortion diagram shows that the distortion of this embodiment is maintained within the range of ±30%.

[0151] From the above description, it can be known that the half viewing angle of the fifth embodiment is greater than the half viewing angle of the first embodiment. Therefore, compared with the first embodiment, the fifth embodiment has a larger angle range for receiving images. The TTL of the fifth embodiment is shorter than the TTL of the first embodiment. Therefore, compared with the first embodiment, the fifth embodiment has a smaller volume. The image height of the fifth embodiment is greater than the image height of the first embodiment. Therefore, compared with the first embodiment, the fifth embodiment has a better sensitivity.

[0152] Fig. 22 FIG. 4 is a schematic diagram of an eyepiece optical system according to a sixth embodiment of the present invention. FIG. 23A to FIG. 23D The longitudinal spherical aberration and various aberration diagrams of the eyepiece optical system of the sixth embodiment. Fig. 22 , the sixth embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the differences between the two are as follows: the optical data, aspheric coefficients, and parameters between the first optical element 1, the second optical element 2, the linear polarization film plus the reflective polarization film 4, and the quarter-wave plate 5 are more or less different. In addition, in this embodiment, the thickness of the first optical element 1 is shortened, which is beneficial to reduce the weight of the eyepiece optical system 10 and shorten the injection molding time of the first optical element 1 to increase production capacity. It should be noted here that in order to clearly display the drawing, Fig. 22 Part of the numbers of the optical axis area and the circumferential area having a surface shape similar to that of the first embodiment are omitted.

[0153] The detailed optical data of the eyepiece optical system 10 of the sixth embodiment are as follows: Fig.24 As shown, the effective focal length of the eyepiece optical system 10 of the sixth embodiment is 23.191 mm, the half viewing angle is 44.999 degrees, the TTL is 21.876 mm, the aperture value is 5.798, and the image height is 16.741 mm.

[0154] Fig.24 The aspheric coefficients of the display side surface 26 of the second optical element 2 of the sixth embodiment in the above formula (1) are also shown.

[0155] In addition, the relationship between the important parameters in the eyepiece optical system 10 of the sixth embodiment is as follows: Fig.39 and Fig.40 shown.

[0156] Fig.23A The longitudinal spherical aberration of the sixth embodiment is shown, and the imaging point deviation of off-axis light rays at different heights is controlled within the range of ±0.12 mm. Fig. 23B and Fig.23C In the two field curvature aberration diagrams, the focal length variation of the three representative wavelengths in the entire field of view falls within ±1.00 mm. Fig.23DThe distortion diagram shows that the distortion of this embodiment is maintained within the range of ±30%.

[0157] It can be known from the above description that the aperture of the sixth embodiment is larger than that of the first embodiment. Therefore, compared with the first embodiment, the sixth embodiment has a larger amount of light entering.

[0158] Fig.25 FIG. 4 is a schematic diagram of an eyepiece optical system according to a seventh embodiment of the present invention. FIG. 26A to FIG. 26D This is a diagram of the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the seventh embodiment. Fig.25 The seventh embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the differences between the two are as follows: the optical data, aspheric coefficients, and parameters between the first optical element 1, the second optical element 2, the linear polarization film plus the reflective polarization film 4, and the quarter-wave plate 5 are more or less different. In addition, in this embodiment, the thickness of the first optical element 1 is shortened, which is conducive to shortening the TTL of the eyepiece optical system 10. It should be noted here that in order to clearly display the drawing, Fig.25 Part of the numbers of the optical axis area and the circumferential area having a surface shape similar to that of the first embodiment are omitted.

[0159] The detailed optical data of the eyepiece optical system 10 of the seventh embodiment are as follows: Fig. 27 As shown, the effective focal length of the eyepiece optical system 10 of the seventh embodiment is 25.391 mm, the half viewing angle is 45.000 degrees, the TTL is 21.027 mm, the aperture value is 6.348, and the image height is 18.052 mm.

[0160] Fig. 27 The aspheric coefficients of the display side surface 26 of the second optical element 2 of the seventh embodiment in the above formula (1) are also shown.

[0161] In addition, the relationship between the important parameters in the eyepiece optical system 10 of the seventh embodiment is as follows: Fig.39 and Fig.40 shown.

[0162] Fig.26A The longitudinal spherical aberration of the seventh embodiment is shown, and the imaging point deviation of off-axis light rays at different heights is controlled within the range of ±0.05 mm. Fig.26B and Fig.26C In the two field curvature aberration diagrams, the focal length variation of the three representative wavelengths in the entire field of view falls within ±1.20 mm. Fig.26D The distortion diagram shows that the distortion of this embodiment is maintained within the range of ±30%.

[0163] From the above description, it can be known that the TTL of the seventh embodiment is shorter than the TTL of the first embodiment. Therefore, compared with the first embodiment, the seventh embodiment has a smaller volume. The image height of the seventh embodiment is greater than the image height of the first embodiment. Therefore, compared with the first embodiment, the seventh embodiment has a better sensitivity. In addition, the longitudinal spherical aberration of the seventh embodiment is smaller than the longitudinal spherical aberration of the first embodiment.

[0164] Fig.28 FIG. 4 is a schematic diagram of an eyepiece optical system according to an eighth embodiment of the present invention. FIG. 29A to FIG. 29D This is a diagram of the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the eighth embodiment. Fig.28 The eighth embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the differences between the two are as follows: the optical data, aspheric coefficients, and parameters between the first optical element 1, the second optical element 2, the linear polarization film plus the reflective polarization film 4, and the quarter-wave plate 5 are more or less different. In addition, in this embodiment, the first optical element 1 has a positive refractive power. The optical axis area 151 of the eye side surface 15 of the first optical element 1 is a convex surface, the circumferential area 153 of the eye side surface 15 of the first optical element 1 is a convex surface, the optical axis area 161 of the display side surface 16 of the first optical element 1 is a convex surface, the circumferential area 163 of the display side surface 16 of the first optical element 1 is a convex surface, the optical axis area 251 of the eye side surface 25 of the second optical element 2 is a concave surface, and the circumferential area 253 of the eye side surface 25 of the second optical element 2 is a concave surface. In addition, the PV value of the eye side surface 15 of the first optical element 1, the display side surface 16 of the first optical element 1, and the eye side surface 25 of the second optical element 2 is designed to be 156 microns. It should be noted that in order to clearly display the diagram, Fig.28 Part of the numbers of the optical axis area and the circumferential area having a surface shape similar to that of the first embodiment are omitted.

[0165] The detailed optical data of the eyepiece optical system 10 of the eighth embodiment are as follows: Fig.30 As shown, the effective focal length of the eyepiece optical system 10 of the eighth embodiment is 22.448 mm, the half viewing angle is 47.500 degrees, the TTL is 19.944 mm, the aperture value is 5.612, and the image height is 16.845 mm.

[0166] Fig.30 The aspheric coefficients of the display side surface 26 of the second optical element 2 of the eighth embodiment in the above formula (1) are also shown.

[0167] In addition, the relationship between the important parameters in the eyepiece optical system 10 of the eighth embodiment is as follows: Fig.39 and Fig.40 shown.

[0168] Fig.29AThe longitudinal spherical aberration of the eighth embodiment is shown, and the imaging point deviation of off-axis light rays at different heights is controlled within the range of ±0.07 mm. Fig.29B and Fig.29C In the two field curvature aberration diagrams, the focal length variation of the three representative wavelengths in the entire field of view falls within ±1.00 mm. Fig.29D The distortion diagram shows that the distortion of this embodiment is maintained within the range of ±30%.

[0169] It can be known from the above description that the half viewing angle of the eighth embodiment is greater than that of the first embodiment. Therefore, compared with the first embodiment, the eighth embodiment has a larger angle range for receiving images. The TTL of the eighth embodiment is shorter than that of the first embodiment. Therefore, compared with the first embodiment, the eighth embodiment has a smaller volume. The aperture of the eighth embodiment is greater than that of the first embodiment. Therefore, compared with the first embodiment, the eighth embodiment has a larger amount of light entering. In addition, the longitudinal spherical aberration of the eighth embodiment is smaller than that of the first embodiment.

[0170] Fig.31 FIG. 4 is a schematic diagram of an eyepiece optical system according to a ninth embodiment of the present invention. FIG. 32A to FIG. 32D This is a diagram of the longitudinal spherical aberration and various aberrations of the eyepiece optical system of the ninth embodiment. Fig.31 The ninth embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the differences between the two are as follows: the optical data, aspheric coefficients, and parameters between the first optical element 1, the second optical element 2, the linear polarization film plus the reflective polarization film 4, and the quarter-wave plate 5 are more or less different. In addition, in this embodiment, the magnification of the eyepiece optical system 10 is increased to reduce the fatigue of the observer under continuous use. It should be noted here that in order to clearly display the drawing, Fig.31 Part of the numbers of the optical axis area and the circumferential area having a surface shape similar to that of the first embodiment are omitted.

[0171] The detailed optical data of the eyepiece optical system 10 of the ninth embodiment are as follows: Fig.33 As shown, the effective focal length of the eyepiece optical system 10 of the ninth embodiment is 23.847 mm, the half viewing angle is 45.000 degrees, the TTL is 21.891 mm, the aperture value is 5.962, and the image height is 17.181 mm.

[0172] Fig.33 The aspheric coefficients of the display side surface 26 of the second optical element 2 of the ninth embodiment in the above formula (1) are also shown.

[0173] In addition, the relationship between the important parameters in the eyepiece optical system 10 of the ninth embodiment is as follows: Fig.39 and Fig.40 shown.

[0174] Fig.32A The longitudinal spherical aberration of the ninth embodiment is shown, and the imaging point deviation of off-axis light rays at different heights is controlled within the range of ±0.09 mm. Fig.32B and Fig.32C In the two field curvature aberration diagrams, the focal length variation of the three representative wavelengths in the entire field of view falls within ±1.00 mm. Fig.32D The distortion diagram shows that the distortion of this embodiment is maintained within the range of ±30%.

[0175] From the above description, it can be known that the aperture of the ninth embodiment is larger than that of the first embodiment. Therefore, compared with the first embodiment, the ninth embodiment has a larger amount of light entering. In addition, the longitudinal spherical aberration of the ninth embodiment is smaller than that of the first embodiment.

[0176] Fig.34 FIG. 4 is a schematic diagram of an eyepiece optical system according to a tenth embodiment of the present invention. FIG. 35A to FIG. 35D The longitudinal spherical aberration and various aberration diagrams of the eyepiece optical system of the tenth embodiment. Fig.34 The tenth embodiment of the eyepiece optical system 10 of the present invention is substantially similar to the first embodiment, and the differences between the two are as follows: the optical data, aspheric coefficients, and parameters between the first optical element 1, the second optical element 2, the linear polarization film plus the reflective polarization film 4, and the quarter-wave plate 5 are more or less different. In addition, in this embodiment, the addition of the third optical element 3 and the optical transparent adhesive 8 is beneficial to improving the imaging quality such as MTF. It should be noted here that in order to clearly display the drawing, Fig.34 Part of the numbers of the optical axis area and the circumferential area having a surface shape similar to that of the first embodiment are omitted.

[0177] The third optical element 3 has a positive refractive power. The optical axis region 351 of the eye side surface 35 of the third optical element 3 is a convex surface, and the circumferential region 353 thereof is a convex surface. The optical axis region 361 of the display side surface 36 of the third optical element 3 is a plane, and the circumferential region 363 thereof is a plane. In this embodiment, the eye side surface 35 of the third optical element 3 is an aspherical surface, but the present invention is not limited thereto.

[0178] Detailed optical data of the eyepiece optical system 10 of the tenth embodiment are as follows: Fig.36 As shown, the effective focal length of the eyepiece optical system 10 of the tenth embodiment is 21.771 mm, the half viewing angle is 45.000 degrees, the TTL is 24.031 mm, the aperture value is 4.354, and the image height is 15.044 mm.

[0179] Fig.36The aspheric coefficients of the display side surface 26 of the second optical element 2 and the eye side surface 36 of the third optical element 3 in the above formula (1) are also shown.

[0180] In addition, the relationship between the important parameters in the eyepiece optical system 10 of the tenth embodiment is as follows: Fig.39 and Fig.40 shown.

[0181] Fig.35A The longitudinal spherical aberration of the tenth embodiment is shown, and the imaging point deviation of off-axis light rays at different heights is controlled within the range of ±0.14 mm. Fig.35B and Fig.35C In the two field curvature aberration diagrams, the focal length variation of the three representative wavelengths in the entire field of view falls within ±0.18 mm. Fig.35D The distortion diagram shows that the distortion of this embodiment is maintained within the range of ±35%.

[0182] From the above description, it can be known that the aperture of the tenth embodiment is larger than that of the first embodiment. Therefore, compared with the first embodiment, the tenth embodiment has a larger amount of incoming light. In addition, the field curvature aberration of the tenth embodiment is smaller than that of the first embodiment.

[0183] The eyepiece side surface 15 of the first optical element 1 and the display side surface 16 of the first optical element 1 of the embodiment of the present invention meet the following conditional formula: PV≦160μm. Therefore, the eyepiece optical system 10 with double reflection optical effect is conducive to reducing the thickness of the second optical element 2 that mainly provides refractive power. Since the time of plastic injection molding is proportional to the square of the element thickness, when the thickness of the second optical element 2 becomes thinner, the production cycle of the second optical element 2 can be shortened to increase product productivity and achieve the purpose of reducing manufacturing costs. In addition, since the eyepiece side surface 15 and the display side surface 16 of the first optical element 1 meet PV≦160μm, it will be helpful to reduce the difficulty of the film pasting process to improve the yield and reduce manufacturing costs. In order to achieve better optical performance, the optimal PV limit is ≦5μm.

[0184] The embodiment of the present invention further limits the absence of an air gap between the display side surface 16 of the first optical element 1 and the eyepiece side surface 25 of the second optical element 2, which is beneficial to mass production of the eyepiece optical system 10 and reduces manufacturing costs.

[0185] Since the distance on the optical axis from the observer's eyes to the image of the eyepiece optical system 10 is proportional to the system length of the eyepiece optical system 10, the eye side surface 15 of the first optical element 1 and the display side surface 16 of the first optical element 1 satisfy PV≦160μm. Therefore, the eyepiece optical system 10 satisfies the conditional formula: 35≦|ObjD| / ImgH≦200, which is conducive to improving the magnification of the eyepiece optical system 10 (i.e., ObjH / ImgH).

[0186] The embodiment of the present invention further limits the eye side surface 25 of the second optical element 2 to satisfy PV≦160μm, and there is no air gap between the display side surface 16 of the first optical element 1 and the eye side surface 25 of the second optical element 2. Therefore, it is advantageous to use an adhesive that matches the refractive index of the first optical element 1 and the refractive index of the second optical element 2 (Nd=1.492~1.543), such as optical glue (Nd=1.540), to bond the second optical element 2 to the display side surface 16 of the first optical element 1. The purpose is to reduce the reflection generated when the light enters the optical glue from the second optical element 2 and enters the first optical element 1 from the optical glue to avoid ghosting. In addition, the above structure is conducive to mass production of the eyepiece optical system 10 and reduces manufacturing costs.

[0187] The first optical element 1 and the second optical element 2 are made of plastic or glass materials with low birefringence, such as APEL, PMMA or BK7, which is beneficial to reducing the stress of the optical elements and thus reducing the chance of ghost images.

[0188] The first optical element 1 is a flat plate, which is conducive to mass production of the eyepiece optical system, reduces the difficulty of the film pasting process and reduces the manufacturing cost.

[0189] The second optical element 2 is a lens, the eye side surface 25 of the second optical element 2 is a plane, and the optical axis region 261 of the display side surface 26 of the second optical element 2 is a convex surface. Therefore, it is beneficial to improve the yield rate of the injection molding of the second optical element 2.

[0190] A linear polarizing film is disposed on the reflective polarizing film, and an anti-reflective film is disposed on the reflective polarizing film to help reduce stray light of the eyepiece optical system 10 .

[0191] The embodiment of the present invention further limits 18≦|ObjD| / SL≦85, 30≦|ObjD| / TTL≦140 and 60≦|ObjD| / TL≦300. Therefore, the magnification of the eyepiece optical system 10 can be increased by increasing the distance and height of the virtual image so that the magnification satisfies 40≦ObjH / ImgH≦200.

[0192] The embodiment of the present invention further limits 1.6≦SL / ImgH≦2.8, 1.6≦ImgH / T1≦10.0 or 2.5≦ImgH / T2≦3.7. Therefore, the magnification of the eyepiece optical system 10 can be increased and the volume and weight of the display can be reduced by reducing the image height.

[0193] The embodiments of the present invention further limit 2.5≦ER12 / T1≦17.0, 3.0≦ER22 / T2≦7.0, 2.0≦(ER11+ER21) / ALT≦10.0 or 1.5≦(ER21+ER22) / TTL≦3.0. Therefore, it is beneficial to reduce the ratio of the effective radius to the thickness of the optical element and improve the yield and production capacity.

[0194] The eyepiece optical system 10 has an eye relief ranging from 5 to 20 mm. Further limiting 1.2≦ER / T1≦30.0 or 2.0≦ER / T2≦4.0 can help maintain a suitable distance between the eyepiece optical system 10 and the eyeball, so that the observer is not easily fatigued.

[0195] The embodiment of the present invention further limits 2.0≦SL / TL≦6.0 or 1.4≦EFL / TL≦3.6. Therefore, it is helpful to reduce the volume and weight of the eyepiece optical system 10.

[0196] Fig.41 A flow chart showing the steps of the mass production method of the eyepiece optical system 10 of the present invention. Fig.42 Schematic diagram showing the mass production method of the eyepiece optical system 10 of the present invention. Fig.41 and Fig.42 . In this embodiment, step S100 is first performed to manufacture a large-sized first optical element 11 with a low birefringence plastic or glass material, wherein the eye side surface 115 of the large-sized first optical element 11 and the display side surface 116 of the large-sized first optical element 11 satisfy the following conditional formula: PV≤160μm, where PV is the peak-to-valley value of the surface. Among them, the eye side surface 115 of the large-sized first optical element 11 and the display side surface 116 of the large-sized first optical element 11 are both planes. The definition of the above-mentioned large size is, for example, an area of ​​21cm×30cm, but the present invention is not limited thereto. In addition, in order to obtain better optical performance, the preferred limit of PV is PV≤5μm.

[0197] Next, step S101 is performed to configure a large-sized reflective polarizing film 14 on the eye-side surface 115 of the large-sized first optical element 11, and a large-sized quarter-wave plate 15 is configured on the display side surface 116 of the large-sized first optical element 11 or between the large-sized reflective polarizing film 14 and the eye-side surface 115 of the large-sized first optical element 11 to form an optical film on the large-sized first optical element 11. In this way, large-area coating of the eyepiece optical system 10 to be produced can be completed at one time.

[0198] Next, step S102 is performed to bond the plurality of second optical elements 2, for example, made by injection molding, to the display side 116 of the large-sized first optical element 11 using an adhesive that matches the refractive index of the large-sized first optical element 11 and the refractive index of the plurality of second optical elements 2, so as to form an assembly 20 consisting of a plurality of eyepiece optical systems 10 arranged in an array. In this way, material waste can be minimized.

[0199] Next, step S103 is performed to cut the aggregate 20 consisting of the plurality of eyepiece optical systems 10 to form a plurality of separate eyepiece optical systems 10. In this way, the production efficiency can be improved and the manufacturing cost can be reduced.

[0200] The contents disclosed in each embodiment of the present invention include but are not limited to optical parameters such as focal length, lens thickness, and Abbe number. For example, the present invention discloses an optical parameter A and an optical parameter B in each embodiment, wherein the ranges covered by these optical parameters, the comparison relationship between the optical parameters, and the conditional ranges covered by multiple embodiments are specifically explained as follows:

[0201] (1) The range covered by the optical parameter, for example: α2≦A≦α1 or β2≦B≦β1, α1 is the maximum value of the optical parameter A in multiple embodiments, α2 is the minimum value of the optical parameter A in multiple embodiments, β1 is the maximum value of the optical parameter B in multiple embodiments, and β2 is the minimum value of the optical parameter B in multiple embodiments.

[0202] (2) The comparative relationship between optical parameters, for example: A is greater than B or A is less than B.

[0203] (3) The conditional range covered by multiple embodiments, specifically, the combination relationship or proportional relationship obtained by possible calculation of multiple optical parameters of the same embodiment, these relationships are defined as E. E can be, for example: A+B or AB or A / B or A*B or (A*B) 1 / 2 , and E satisfies the conditional formula E≦γ1 or E≧γ2 or γ2≦E≦γ1, γ1 and γ2 are the values ​​obtained by calculating the optical parameters A and the optical parameters B of the same embodiment, and γ1 is the maximum value among multiple embodiments of the present invention, and γ2 is the minimum value among multiple embodiments of the present invention.

[0204] The ranges covered by the above optical parameters, the comparison relationship between the optical parameters, and the maximum and minimum values ​​of the conditional expressions, as well as the numerical ranges within the maximum and minimum values, are all features that can be implemented by the present invention and are within the scope disclosed by the present invention. The above is only an example and should not be limited to this.

[0205] All embodiments of the present invention can be implemented, and some feature combinations can be extracted from the same embodiment. Compared with the prior art, the feature combination can also achieve unexpected effects of the present case. The feature combination includes but is not limited to the combination of features such as face shape, refractive index and conditional formula. The disclosure of the implementation mode of the present invention is a specific embodiment to illustrate the principle of the present invention, and the present invention should not be limited to the disclosed embodiment. In other words, the embodiment and its drawings are only for demonstration of the present invention and are not limited thereto.

Claims

1. An eyepiece optical system, configured to allow imaging light from a display screen to pass through the eyepiece optical system and enter an eye of an observer to form an image, wherein a side facing the eye is an eye side and a side facing the display screen is a display side, the eyepiece optical system sequentially comprises a first optical element and a second optical element along an optical axis from the eye side to the display side, the first optical element and the second optical element each comprising an eye side surface facing the eye side and allowing the imaging light to pass through and a display side surface facing the display side and allowing the imaging light to pass through, the eyepiece optical system further comprising a reflective polarizing film and a quarter-wave plate; The eye side surface of the first optical element and the display side surface of the first optical element satisfy the following conditional formula: PV≤160μm, where PV is a peak-to-valley value on a surface; The reflective polarizing film is disposed on the eye side of the first optical element; The quarter-wave plate is disposed on the display side of the first optical element or between the reflective polarizing film and the eye side of the first optical element; in, The eyepiece optical system satisfies the following conditions: 35≤|ObjD| / ImgH≤200, wherein ObjD is the distance from the eye of the observer to the image formed by the eyepiece optical system on the optical axis, and ImgH is the maximum image height of the eyepiece optical system.

2. An eyepiece optical system, configured to allow imaging light from a display screen to pass through the eyepiece optical system and enter an eye of an observer to form an image, wherein a side facing the eye is an eye side and a side facing the display screen is a display side, the eyepiece optical system sequentially comprises a first optical element and a second optical element along an optical axis from the eye side to the display side, the first optical element and the second optical element each comprising an eye side surface facing the eye side and allowing the imaging light to pass through and a display side surface facing the display side and allowing the imaging light to pass through, the eyepiece optical system further comprising a reflective polarizing film and a quarter-wave plate; The eye side surface of the first optical element, the display side surface of the first optical element, and the eye side surface of the second optical element satisfy the following conditional formula: PV≤160μm, where PV is a peak-to-valley value on a surface; The reflective polarizing film is disposed on the eye side of the first optical element; The quarter-wave plate is disposed on the display side of the first optical element or between the reflective polarizing film and the eye side of the first optical element; There is no air gap between the display side surface of the first optical element and the eye side surface of the second optical element.

3. The eyepiece optical system as claimed in claim 1 or 2, wherein a linear polarizing film is disposed on the reflective polarizing film, and an anti-reflection film is disposed on the reflective polarizing film. 4 . The eyepiece optical system as claimed in claim 1 , wherein the eye-side surface of the first optical element and the display-side surface of the first optical element satisfy the following condition: PV≤5 μm.

5. The eyepiece optical system of claim 2, wherein the eyepiece optical system further satisfies the following equation: 60≤|ObjD| / ImgH≤200, wherein ObjD is the distance from the eye of the observer to the image formed by the eyepiece optical system on the optical axis, and ImgH is the maximum image height of the eyepiece optical system.

6. The eyepiece optical system of claim 2, wherein the eyepiece optical system further satisfies the following equation: 18≤|ObjD| / SL≤85, wherein ObjD is the distance from the eye of the observer to the image formed by the eyepiece optical system on the optical axis, and SL is the distance from the eye of the observer to the display screen on the optical axis.

7. The eyepiece optical system as described in claim 2, wherein the eyepiece optical system further satisfies the following formula: 1.6≦SL / ImgH≦2.8, wherein SL is the distance from the eye of the observer to the display screen on the optical axis, and ImgH is the maximum image height of the eyepiece optical system.

8. The eyepiece optical system of claim 1 or 2, wherein the eyepiece optical system further satisfies the following equation: 2.5≤ER12 / T1≤17.0, wherein ER12 is the maximum distance from the center of the display side of the first optical element to the mounting portion, and T1 is the thickness of the first optical element on the optical axis.

9. The eyepiece optical system of claim 1 or 2, wherein the eyepiece optical system further satisfies the following equation: 2.0≤(ER11+ER21) / ALT≤10.0, wherein ER11 is the maximum distance from the center of the eye-side surface of the first optical element to the mounting portion, ER21 is the maximum distance from the center of the object-side surface of the second optical element to the mounting portion, and ALT is the sum of the thicknesses of the first optical element and the second optical element on the optical axis.

10. The eyepiece optical system of claim 1 or 2, wherein the eyepiece optical system further satisfies the following equation: 1.2≤ER / T1≤30.0, wherein ER is the distance from the eye of the observer to the first optical element on the optical axis, and T1 is the thickness of the first optical element on the optical axis.

11. The eyepiece optical system of claim 1 or 2, wherein the eyepiece optical system further satisfies the following equation: 2.0≤SL / TL≤6.0, wherein SL is the distance from the eye of the observer to the display screen on the optical axis, and TL is the distance from the eye side of the optical element closest to the eye side to the display side of the second optical element on the optical axis.

12. The eyepiece optical system of claim 1 or 2, wherein the display side surface of the second optical element is a convex surface.

13. The eyepiece optical system of claim 2, wherein the eyepiece optical system further satisfies the following equation: 30≤|ObjD| / TTL≤140, wherein ObjD is the distance from the eye of the observer to the image formed by the eyepiece optical system on the optical axis, and TTL is the distance from the eye side of the optical element closest to the eye side to the display screen on the optical axis.

14. The eyepiece optical system of claim 2, wherein the eyepiece optical system further satisfies the following equation: 60≤|ObjD| / TL≤300, wherein ObjD is the distance from the eye of the observer to the image formed by the eyepiece optical system on the optical axis, and TL is the distance from the eye side of the optical element closest to the eye side to the display side of the second optical element on the optical axis.

15. The eyepiece optical system as claimed in claim 2, wherein the eyepiece optical system further satisfies the following equation: 2.5≤ImgH / T2≤3.7, wherein ImgH is the maximum image height of the eyepiece optical system, and T2 is the thickness of the second optical element on the optical axis.

16. The eyepiece optical system of claim 1 or 2, wherein the eyepiece optical system further satisfies the following equation: 3.0≤ER22 / T2≤7.0, wherein ER22 is the maximum distance from the center of the display side of the second optical element to the mounting portion, and T2 is the thickness of the second optical element on the optical axis.

17. The eyepiece optical system of claim 1 or 2, wherein the eyepiece optical system further satisfies the following equation: 1.5≤(ER21+ER22) / TTL≤3.0, wherein ER21 is the maximum distance from the center of the object side surface of the second optical element to the mounting portion, ER22 is the maximum distance from the center of the display side surface of the second optical element to the mounting portion, and TTL is the distance from the eye side surface of the optical element closest to the eye side to the display screen on the optical axis.

18. The eyepiece optical system of claim 1 or 2, wherein the eyepiece optical system further satisfies the following equation: 2.0≤ER / T2≤4.0, wherein ER is the distance from the eye of the observer to the first optical element on the optical axis, and T2 is the thickness of the second optical element on the optical axis.

19. The eyepiece optical system of claim 1 or 2, wherein the eyepiece optical system further satisfies the following equation: 1.4≤EFL / TL≤3.6, wherein EFL is the effective focal length of the eyepiece optical system, and TL is the distance from the eye side of the optical element closest to the eye side to the display side of the second optical element on the optical axis.

20. A mass production method for an eyepiece optical system, comprising: A large-sized first optical element is manufactured from a low-birefringence plastic or glass material, wherein an eye side surface of the large-sized first optical element and a display side surface of the large-sized first optical element satisfy the following conditions: PV≤160 μm, wherein PV is a peak-to-valley value of the surface; Disposing a large-sized reflective polarizing film on the eye side of the large-sized first optical element, and disposing a large-sized quarter-wave plate on the display side of the large-sized first optical element or between the large-sized reflective polarizing film and the eye side of the large-sized first optical element to form an optical film on the large-sized first optical element; Using an adhesive that matches the refractive index of the large-sized first optical element and the refractive index of a plurality of second optical elements, the plurality of second optical elements are bonded to the display side of the large-sized first optical element to form an assembly consisting of a plurality of eyepiece optical systems arranged in an array; and The assembly consisting of the eyepiece optical systems is cut to form separate eyepiece optical systems.

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