Optical system based on OLEDoS display chip

Abstract

The invention provides an optical system based on an OLEDoS display chip, and the system comprises a plurality of lenses which comprise a fourth lens to a first lens which are sequentially arranged from the image source side to the human eye observation side of the optical system, and each lens is provided with a first side surface facing the human eye observation side and a second side surface facing the image source side; the polarization control assembly comprises a first composite membrane and a second composite membrane, the first composite membrane is arranged on the first lens or the second lens, the second composite membrane is arranged on the first side face of the third lens, and the polarization control assembly is used for controlling the polarization direction of light; the light splitting film is arranged on the second side face of the second lens, and the light splitting film is used for transmitting at least one part of the light rays and reflecting at least the other part of the light rays; and the display assembly comprises an OLEDoS display screen. According to the invention, the problem that high resolution and low ghost image of an optical system based on an OLEDoS display chip in the prior art are difficult to consider at the same time is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical imaging equipment, and in particular to an optical system based on an OLEDoS display chip. Background Art

[0002] In order to shorten the optical size, projection products now often use a folded optical path to achieve the folding of light, thereby shortening the total optical length and reducing the overall size of the projection product. This method is called a pancake solution. Due to the folding of the optical path, when the folding is achieved by internal reflection in the optical system using the pancake solution, the optical system may have ghost image problems. According to the current coating process level, even if an AR film (anti-reflection film) is coated, the reflection of the lens will still cause ghost images. This phenomenon will become more serious as the number of optical lenses increases. The reflection of the lens will also appear more due to the increase in the distance of the light, which will also lead to an increase in ghost images. In addition, resin lenses are mostly used in existing optical systems, which have stress problems. The more lenses there are, the greater the stress, and the polarization state in the folded optical path will deviate, which will be reflected in the light leakage ghost image.

[0003] Therefore, in the pancake solution, the more lenses there are, the more reflective surfaces there are, and the ghost images will become stronger, which will limit the number of lenses for each manufacturer. Therefore, each manufacturer is now more restrained in the number of lenses. The screens used in the current pancake solution are mostly Fast-LCD (fast liquid crystal display) screens. Compared with OLED chips or silicon-based OLED chips, the pixel size of Fast-LCD screens is larger, and due to process limitations, it is impossible to achieve small size and high resolution at the same time. Therefore, the current pancake solution does not require high resolution for the optical system, and generally uses 2 lenses. This results in the optical system size of the pancake solution based on LCD display being larger and the resolution being limited, with a PPD of usually around 20. The screen effect caused by low resolution greatly affects the user experience of the VR-HMD module.

[0004] In other words, the optical system based on OLEDoS display chip in the prior art has the problem of having difficulty in achieving both high resolution and low ghost images. Summary of the invention

[0005] The main purpose of the present invention is to provide an optical system based on an OLEDoS display chip to solve the problem in the prior art that it is difficult to achieve both high resolution and low ghost images in an optical system based on an OLEDoS display chip.

[0006] In order to achieve the above-mentioned purpose, the present invention provides an optical system based on an OLEDoS display chip, comprising: a plurality of lenses, the plurality of lenses comprising a fourth lens to a first lens arranged in sequence from an image source side to a human eye observation side of the optical system, the lens 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 comprising a first composite film and a second composite film, the first composite film being arranged on the first lens or the second lens, the second composite film being arranged on a first side of a third lens, the polarization control component being used to control the polarization direction of light; a spectroscopic film, the spectroscopic film being arranged on a second side of the second lens, the spectroscopic film being used to transmit at least a portion of the light and reflect at least another portion of the light; a display component, the display component comprising an OLEDoS display screen.

[0007] Furthermore, the second composite film includes, from the image source side to the human eye observation side: a first polarizer, which is used to transmit the first light with a first linear polarization direction; and a first wave plate, which is used to convert the first light into a second light with a first circular polarization direction.

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

[0009] Furthermore, 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 wave plate, which is arranged on the side of the first polarizer facing the image source side to make the polarization direction of the second light the same as or opposite to that of the original light.

[0011] Furthermore, both the first wave plate and the second wave plate are 1 / 4 wave plates, and the fast axes of the first wave plate and the second wave plate are perpendicular.

[0012] Furthermore, the second composite film also includes a first anti-reflection film, and the first anti-reflection film is arranged on a side of the first wave plate facing the human eye observation side.

[0013] Furthermore, the first composite film includes, from the image source side to the human eye observation side: a third wave plate, which is used to convert the second light into a third light with a second linear polarization direction; a polarization beam splitter, which is used to reflect the third light, so that the third light is first reflected once by the polarization beam splitter, then passes through the third wave plate, and then is reflected twice by the beam splitter film and then passes through the third wave plate again, and is converted into a fourth light with a third linear polarization direction, and the polarization beam splitter can transmit the fourth light.

[0014] Furthermore, the third wave plate is a 1 / 4 wave plate.

[0015] Furthermore, the first composite film further includes a second anti-reflection film, and the second anti-reflection film is arranged on a side of the third wave plate facing the image source.

[0016] Furthermore, the first composite film also includes a second polarizer, and the second polarizer is used for transmitting the fourth light.

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

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

[0019] Furthermore, the second lens has positive optical power, and the first side surface and the second side surface of the second lens are both 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 surface of the fourth lens is a convex surface, and the second side surface of the fourth lens is a plane.

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

[0023] Furthermore, the material of the plurality of lenses is resin material.

[0024] Further, at least two lenses among the plurality of lenses have materials with different Abbe numbers.

[0025] Furthermore, the number of side surfaces of the lens between the first composite film sheet and the second composite film sheet 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-reflection coating.

[0027] By applying the technical solution of the present invention, an optical system based on an OLEDoS display chip includes a plurality of lenses, a polarization control component, a spectroscopic film and a display component, wherein the plurality of lenses include a fourth lens to a first lens arranged in sequence from an image source side to a human eye observation side of the optical system, and the 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 sheet and a second composite film sheet, the first composite film sheet is arranged on the first lens or the second lens, the second composite film sheet is arranged on a first side surface of the third lens, and the polarization control component is used to control the polarization direction of light; the spectroscopic film is arranged on a second side surface of the second lens, and the spectroscopic film 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 adopting a multi-lens design, especially a four-lens design, the resolution of the optical system is improved to adapt to the OLEDoS display screen, so that the chip resolution and the resolution of the optical system can give full play to their advantages. The light transmission or reflection is controlled by the beam splitter film, and the folded light path meets the miniaturization requirements of the optical system. The polarization state of the light is controlled by the polarization control component, so that the light participating in the imaging has a specific polarization state conversion, thereby limiting the propagation of non-imaging light and reducing the ghost image of the optical system. The first composite film and the second composite film are respectively arranged on different lens sides, which can filter the light reflected from different lens surfaces, thereby reducing the transmission of non-imaging light and ghost images. The second composite film is arranged on the first side of the third lens, which can control the polarization state of the front light from the display component and reduce the propagation of non-imaging light to the rear. By arranging the first composite film on the first lens or the second lens, the polarization state of the light before it is emitted to the human eye observation side is controlled again, further intercepting the non-imaging light and reducing ghost images. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0030] Figure 1 A schematic structural diagram of an optical system according to a first embodiment of the present invention is shown;

[0031] Figure 2 A schematic structural diagram of an optical system according to a second embodiment of the present invention is shown;

[0032] Figure 3 A schematic structural diagram of an optical system according to a fifth embodiment of the present invention is shown;

[0033] Figure 4 Shows Figure 3 MTF diagram of the optical system in;

[0034] Figure 5 Shows Figure 3 MTF through-focus diagram of the optical system in;

[0035] Figure 6 Shows Figure 3 MTF diagram of the optical system in different fields of view;

[0036] Figure 7 A schematic diagram showing the structure of an optical system according to a sixth embodiment of the present invention is shown;

[0037] Figure 8 Shows Figure 7 MTF diagram of the optical system in;

[0038] Fig. 9 Shows Figure 7 MTF through-focus diagram of the optical system in;

[0039] Fig.10 Shows Figure 7 MTF diagram of the optical system in different fields of view;

[0040] Fig.11 A schematic diagram showing the structure of an optical system according to a seventh embodiment of the present invention is shown;

[0041] Fig.12 Shows Fig.11 MTF diagram of the optical system in;

[0042] Fig.13 Shows Fig.11 MTF through-focus diagram of the optical system in;

[0043] Fig.14 Shows Fig.11 MTF diagram of the optical system at different fields of view.

[0044] The above drawings 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 component; 11, first composite film; 111, third wave plate; 112, polarization beam splitter; 113, second anti-reflection film; 114, second polarizer; 12, second composite film; 121, first polarizer; 122, first wave plate; 123, first anti-reflection film; 124, second wave plate; 20, beam splitter; 30, display component; 31, OLEDoS display screen; 32, third anti-reflection film; 33, third polarizer; 34, fourth wave plate. DETAILED DESCRIPTION

[0046] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0047] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0048] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0049] In order to solve the problem in the prior art that it is difficult to achieve both high resolution and low ghost images in an optical system based on an OLEDoS display chip, the present invention provides an optical system based on an OLEDoS display chip.

[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 splitter film 20 and a display component 30. The multiple lenses include a fourth lens to a first lens arranged in sequence from the image source side to the human eye observation side of the optical system, and the 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 sheet 11 and a second composite film sheet 12, the first composite film sheet 11 is arranged on the first lens or the second lens, and the second composite film sheet 12 is arranged on the first side of the third lens, and the polarization control component 10 is used to control the polarization direction of the light; the splitter film 20 is arranged on the second side of the second lens, and the splitter film 20 is used to transmit at least a part of the light and reflect at least another part of the light; the display component 30 includes an OLEDoS display screen 31.

[0051] By adopting a design of multiple lenses, especially four lenses, the resolution of the optical system is improved to adapt to the OLEDoS display screen 31, so that the chip resolution and the resolution of the optical system can give full play to their advantages. The light transmission or reflection is controlled by the beam splitter 20, and the folded light path meets the miniaturization requirements of the optical system. The polarization state of the light is controlled by the polarization control component 10, so that the light participating in the imaging has a specific polarization state conversion, thereby limiting the propagation of non-imaging light and reducing the ghost image of the optical system. The first composite film 11 and the second composite film 12 are respectively arranged on different lens sides, which can filter the light reflected from different lens surfaces, thereby reducing the transmission of non-imaging light and reducing ghost images. The second composite film 12 is arranged 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. By arranging the first composite film 11 on the first lens or the second lens, the polarization state of the light before it is emitted to the human eye observation side is controlled again, further intercepting the non-imaging light and reducing ghost images.

[0052] The optical system of the present application can also fold the optical path to ensure miniaturization while leaving enough back focus distance to realize the built-in assembly of the module.

[0053] Optionally, the first lens has a negative optical power, and the first side surface of the first lens is a concave surface, which is beneficial to increase the viewing angle and enhance the viewing comfort of human eyes.

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

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

[0056] Of course, the second side surface of the first lens may also be set to be a plane, which is beneficial to improving the yield rate of the attached film material and reducing the defects caused by curved surface attachment.

[0057] Optionally, the second lens has positive optical power, and the first side surface and the second side surface of the second lens are both convex. The third lens has positive optical power, and the first side surface of the third lens is a plane. The fourth lens has positive optical power, the first side surface of the fourth lens is a convex surface, and the second side surface of the fourth lens is a plane. By controlling the optical power and surface shape of the first lens to the fourth lens as described above, it is possible to avoid excessive deflection of edge light on a certain lens surface, reduce large field of view aberrations, and provide high-resolution image display. The design of a plane surface on one side of the lens is conducive to the attachment of film materials and improves imaging quality.

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

[0059] Optionally, all lenses are aspherical lenses.

[0060] Optionally, the material of the multiple lenses is resin material, which is beneficial to reducing costs and also can reduce product weight.

[0061] Optionally, at least two of the multiple lenses have materials with different Abbe numbers. The combination of materials with different Abbe numbers is beneficial to correcting chromatic aberration, reducing chromatic aberration of the optical system, and improving imaging quality.

[0062] Optionally, the material of the second lens is a low-stress birefringence resin material, and the delay (stress) is less than <10 nm.

[0063] Specifically, the number of the side surfaces of the lens between the first composite film 11 and the second composite film 12 is less than or equal to two, which can achieve the effect of reducing the ghost image caused by the unexpected optical interface reflection. Since the number of optical interfaces between the first composite film 11 and the second composite film 12 is smaller, that is, the number of lenses contained in the middle is smaller, the ghost image situation is better, and stray light can be reduced 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-reflection coating, which helps to reduce ghost images caused by stray light reflected from the lens surface.

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

[0066] Optionally, the display assembly 30 further includes a third anti-reflection film 32 and a third polarizer 33 to ensure the brightness while ensuring the polarization direction of the original light.

[0067] Embodiment 1

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

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

[0070] The linearly polarized light emitted from the display assembly 30 is first converted into a first light with a first linear polarization direction through the first polarizer 121, and then the first light is converted into a second light with a first circular polarization direction through the first wave plate 122 to propagate backward. In other words, when the original light reaches the second composite film 12, due to passing through the fourth lens and the third lens, there is a polarization state deviation caused by reflection and stress on the lens surface, which greatly increases the risk of forming ghost images. The first polarizer 121 and the first wave plate 122 can transmit and convert light of a specific polarization state, thereby intercepting invalid light and reducing the risk of forming ghost images.

[0071] By setting the second composite film 12 to select the polarization state of light, the reflected light from the third lens, the fourth lens, the image source and the light of unexpected polarization state can be blocked from entering the first lens and the second lens, effectively reducing the intensity of ghost images in the optical system. At the same time, the surface coating requirements for the third lens and the fourth lens can be effectively reduced; the range of material selection for the third lens and the fourth lens is increased, providing greater freedom for design, reducing processing difficulty, reducing chromatic aberration of the optical system, and improving imaging quality.

[0072] Optionally, the second composite film 12 further includes a first anti-reflection film 123, which is disposed on the side of the first wave plate 122 facing the human eye observation side. By providing the first anti-reflection film 123, the light transmittance can be improved and the brightness of the optical system can be increased.

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

[0074] like Figure 1 As shown, the first composite film 11 includes a third wave plate 111 and a polarization beam splitter 112 from the image source side to the human eye observation side. The third wave plate 111 is used to convert the second light into a third light with a second linear polarization direction; the polarization beam splitter 112 is used to reflect the third light, so that the third light first passes through the polarization beam splitter 112 for one reflection, then passes through the third wave plate 111, and then is reflected twice by the beam splitter film 20 and passes through the third wave plate 111 again, and is converted into a fourth light with a third linear polarization direction. The polarization beam splitter 112 can transmit the fourth light. Preferably, the third wave plate is a 1 / 4 wave plate.

[0075] That is to say, the second light emitted from the second composite film 12 that effectively participates in the imaging is transmitted through the beam splitter film 20 and the second lens in sequence, and then reaches the first composite film 11, and then is transmitted through the third wave plate 111 and reflected by the polarization beam splitter 112, and then is transmitted through the third wave plate 111 and the second lens again, and is reflected when it reaches the beam splitter film 20, and then is transmitted through the second lens and the third wave plate 111 again, and is transmitted when it reaches the polarization beam splitter 112 again. Thus, the light path is folded under the transmission and reflection of the beam splitter film 20 and the polarization beam splitter 112, and at the same time, only light of a specific polarization state can be finally transmitted by the polarization beam splitter 112.

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

[0077] like Figure 1 As shown, the first composite film 11 further includes a second anti-reflection film 113, which is disposed on a side of the third wave plate 111 facing the image source. The second anti-reflection film 113 is advantageous for increasing light transmittance and brightness.

[0078] like Figure 1 As shown, the first composite film 11 further includes a second polarizer 114, and the second polarizer 114 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 to prevent the light except the third linear polarization direction from being emitted from the first composite film 11, thereby reducing the probability of ghost images.

[0079] like Figure 1As shown, in this embodiment, the original light emitted by the display component 30 is S polarized light in the vertical direction. After reaching the first polarizer 121 on the second composite film 12, the first polarizer 121 can transmit the S polarized light. At this time, the fast axis angle between the S polarized light and the first wave plate 122 is 45°, so that the S polarized light is converted into left-handed polarized light after passing through the first wave plate 122, and then passes through the beam splitter 20 (the energy of the light after passing through becomes 50% of the energy of the original light), the second lens, and the third wave plate 111 in the first composite film 11 in sequence, and 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 polarization beam splitter 112. The reflected light of the P polarized light after being reflected by the polarization beam splitter 112 is -45° with the fast axis of the third wave plate 111. ° angle state, thus P polarized light is converted into left-handed polarized light after passing through the third wave plate 111, when the left-handed polarized light passes through the second lens and reaches the beam splitter 20, about 50% of the light will be reflected (thereby the energy of the light becomes 25% of the original light energy), and the left-handed polarized light after reflection will become right-handed polarized light, and the right-handed polarized light will be converted into P polarized light after passing through the third wave plate 111 in the first composite film 11, and the polarization direction is -45° with the fast axis angle of the third wave plate 111 (the fast axis is 45° counterclockwise), at this time, the polarization direction of the light is consistent with the transmission direction of the polarization beam splitter 112, and the light is consistent with the transmission axis direction of the polarization beam splitter 112, so the P polarized light can pass through the polarization beam splitter 112 and the second polarizer 114, and finally exit through the first lens.

[0080] In this embodiment, the light emitted by the display assembly 30 can be folded back in the lens, so that the light can pass through multiple optical curved surfaces, so that the light is modulated multiple times. Compared with the solution of directly penetrating the lens, this embodiment can greatly shorten the size of the entire optical system. In this embodiment, the gap between the components in the optical system is increased, thereby increasing the optical path of the light and shortening the total path of the optical system.

[0081] Embodiment 2

[0082] like Figure 2 As shown, the difference from the first embodiment is that the polarization direction of the original light emitted by 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 assembly 30 is circularly polarized light, and the ellipticity of the original light is greater than 0.95.

[0084] like Figure 2 As shown, the second composite film 12 further includes a second wave plate 124, which is disposed on a side of the first polarizer 121 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.

[0085] Specifically, the first wave plate 122 and the second wave plate 124 are both quarter wave plates, and the fast axes of the first wave plate 122 and the second wave plate 124 are perpendicular to each other to ensure that the polarization direction of the second light is the same as or opposite to that of the original light.

[0086] like Figure 2 As shown, in the present embodiment, the display component 30 also includes a fourth wave plate 34. The light emitted by the OLEDoS display screen 31 is S-polarized light with a fast axis angle of -45° with the fourth wave plate 34 after passing through the third polarizer 33. After passing through the fourth wave plate 34, it is converted into the original light of left-handed polarized light and emitted. After being transmitted by the fourth lens and the third lens, it reaches the second wave plate 124 in the second composite film 12. The second wave plate 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 fast axis angle between the P-polarized light and the first wave plate 122 is -45°, so that the P-polarized light is converted into left-handed polarized light after passing through the first wave plate 122. The optical path thereafter is the same as that in the first embodiment and will not be repeated here.

[0087] Embodiment 3

[0088] In a specific embodiment not shown in the figure, the difference from the first embodiment is that the first composite film 11 is attached to the first side surface of the first lens.

[0089] Embodiment 4

[0090] In a specific embodiment not shown in the figure, the difference from the first embodiment is that the first composite film 11 is attached to the first side surface of the second lens.

[0091] Embodiment 5

[0092] like Figures 3 to 6 As shown, an optical system of Embodiment 5 is shown. It should be noted that the above Embodiment 1 and Embodiment 2 are both applicable to this embodiment.

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

[0094] The focal length of the optical system is f, the maximum field of view 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 = 15.34 ± 1 mm; FOV = 95° ± 1°, TTL = 19.8 ± 1 mm. The display component 30 includes an OLEDoS display screen 31 with a size of 1.3 inches and 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 of this embodiment, wherein the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0097]

[0098]

[0099] Table 1

[0100] It should be noted that, in the present embodiment, the radius of curvature of the second side surface of the third lens is actually a relatively large positive number. However, in Table 1, for the convenience of expression, the radius of curvature of the second side surface of the third lens is infinite. In fact, 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, and the surface shape of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0102]

[0103] Where X represents the aspheric surface sag, which is a function of the coordinate position Y, which is the radial distance from the origin. R is the radius of curvature, k is the quadratic constant (conic coefficient), i represents the order, and A i is the aspheric coefficient of the corresponding order. X, Y, R are in millimeters, k, i, A i Dimensionless. In the formula (Y 2 / R) / (1+sqrt(1-(1+k)×(Y / R) 2 )) is the quadratic basis, is the offset of the surface compared to the quadratic 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 coefficients A4, A6, A8, A10, A12, A14, A16 of the high-order terms 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 at 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 known 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 diaphragm 11, a second lens E2, a beam splitter film 20, a second composite diaphragm 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. Among them, the first composite diaphragm 11 is attached to the second side surface of the first lens, the beam splitter film 20 is attached to the second side surface of the second lens, and the second composite diaphragm 12 is attached to the first side surface 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 surface 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 of this embodiment, wherein the units of the 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 not limited to, formula (1) in Embodiment 5.

[0119] Table 4 lists the high-order coefficients of the aspherical mirror surfaces that can be used 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 of Example 6 is shown. Fig. 9 The MTF through-focus diagram of the optical system of Example 6 is shown. Fig.10 The MTF diagrams of the optical system of Example 6 under different fields of view are shown. In this embodiment, the optical system can provide high-resolution image display, and can achieve MTF>0.4 at 80lp / mm.

[0123] according to Figures 8 to 10 It can be seen that the optical system provided in Example 6 can achieve good imaging quality.

[0124] Embodiment 7

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

[0126] The focal length of the optical system is f, the maximum field of view 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 = 14.155 ± 1 mm; FOV = 106° ± 1°, TTL = 18.25 ± 1 mm. The display component 30 includes an OLEDoS display screen 31 with a size of 1.3 inches and an image plane length of 24.2 mm.

[0127] like Fig.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 a basic structural parameter table of the optical system of this embodiment, wherein the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0129]

[0130]

[0131] Table 5

[0132] In this embodiment, the first side surface and the second 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 not limited to, formula (1) in Embodiment 5.

[0133] Table 6 lists the high-order coefficients of the aspherical mirror surfaces that can be used 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] Fig.12 The MTF (Modulation Transfer Function) diagram of the optical system of the seventh embodiment is shown. Fig.13 The MTF through-focus diagram of the optical system of Example 7 is shown. Fig.14 The MTF diagrams of the optical system of Example 7 under different fields of view are shown. In this embodiment, the optical system can provide high-resolution image display, and can achieve MTF>0.4 at 80lp / mm.

[0137] according to Figure 12 to Figure 14 It can be seen that the optical system provided in the seventh embodiment can achieve good imaging quality.

[0138] From the above description, it can be seen that the above 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 adapt to the OLEDoS display 31, so that the chip resolution and the resolution of the optical system can give full play to their advantages.

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

[0141] 3. The polarization state of the light is controlled by the polarization control component 10, so that the light participating in the imaging has a specific polarization state conversion, thereby limiting the propagation of non-imaging light and reducing the ghost image of the optical system.

[0142] 4. The first composite film 11 and the second composite film 12 are respectively arranged on different sides of the lens, so as to filter the light reflected from different lens surfaces, thereby reducing the transmission of non-imaging light and ghost images.

[0143] 5. The second composite film 12 is arranged on the first side surface of the third lens, so as to control the polarization state of the front light from the display component 30 and reduce the non-imaging light propagating backward.

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

[0145] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0146] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

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

[0148] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope 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 lens to a first lens arranged in sequence from the image source side to the human eye observation side of the optical system, the lenses having a first side surface facing the human eye observation side and a second side surface facing the image source side; A polarization control component (10), the polarization control component (10) comprising a first composite film (11) and a second composite film (12), the first composite film (11) being arranged on the first lens or the second lens, the second composite film (12) being arranged on a first side surface of a third lens, the polarization control component (10) being used to control the polarization direction of light; a dichroic film (20), the dichroic film (20) being arranged on the second side surface of the second lens, the dichroic film (20) being used to transmit at least a portion of the light and reflect at least another portion of the light; A display component (30), wherein the display component (30) comprises an OLEDoS display screen (31).

2. The optical system based on OLEDoS display chip according to claim 1, characterized in that: The second composite film (12) comprises, from the image source side to the human eye observation side: A first polarizer (121), the first polarizer (121) being used for transmitting a first light having a first linear polarization direction; A first wave plate (122), wherein the first wave plate (122) is used to transform the first light into a second light having a first circular polarization direction.

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

4. The optical system based on 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 OLEDoS display chip according to claim 2, characterized in that: The original light emitted by the display component (30) is circularly polarized light, and the second composite film (12) further comprises a second wave plate (124), wherein the second wave plate (124) is arranged on a side of the first polarizer (121) 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.

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

7. The optical system based on OLEDoS display chip according to claim 2, characterized in that: The second composite film (12) further comprises a first anti-reflection film (123), wherein the first anti-reflection film (123) is arranged on a side of the first wave plate (122) facing the human eye observation side.

8. The optical system based on OLEDoS display chip according to claim 2, characterized in that: The first composite film (11) comprises, from the image source side to the human eye observation side: A third wave plate (111), the third wave plate (111) being used to transform the second light into a third light having a second linear polarization direction; A polarizing beam splitter (112), the polarizing beam splitter (112) being used to reflect a third light, so that the third light first passes through the polarizing beam splitter (112) for a single reflection, then passes through the third wave plate (111), is then reflected twice by the beam splitter film (20), and then passes through the third wave plate (111) again, thereby being transformed into a fourth light having a third linear polarization direction, and the polarizing beam splitter (112) is capable of transmitting the fourth light.

9. The optical system based on OLEDoS display chip according to claim 8, characterized in that: The third wave plate (111) is a quarter wave plate.

10. The optical system based on OLEDoS display chip according to claim 8, characterized in that: The first composite film (11) further comprises a second anti-reflection film (113), wherein the second anti-reflection film (113) is arranged on a side of the third wave plate (111) facing the image source.

Images