TWI779789B - Optical system with augmented reality - Google Patents

Abstract

An optical system with augmented reality, including a display screen emitting light; and a light guide element, including an incident surface and a plurality of reflective surfaces, the incident surface is arranged on the top of the light guide element and exits from one of the reflective surfaces The reflective surfaces are adjacent, the outgoing reflective surface is the surface opposite to a human eye, the display screen is set opposite to the incident surface, so that the light enters the light guide element from the incident surface, and after three reflections on the reflective surfaces in the light guide element, it passes through the The exit reflective surface guides light into the human eye. In the present invention, the display screen is arranged above the light guide element, and through two total reflections and one partial penetration and partial reflection, the lens has the effect of correcting the diopter of the eyes and augmenting reality at the same time, and reduces the thickness of the optical system. , to achieve a light and thin effect.

Description

Optical system with augmented reality

The invention relates to an optical structure, in particular to an optical system with augmented reality.

Wearable devices are considered to be one of the electronic products with the greatest market growth potential after smart phones. Wearable devices can be classified into glasses type, watch type, wearing type, wearable type and attachment type according to different wearing types. The application of wearable devices combined with virtual reality (Virtual Reality, VR), mixed reality (Mixed Reality, MR) or augmented reality (Augmented Reality, AR) is gradually increasing. Taking AR glasses as an example, how to make the lenses light and thin, so that the glasses can also have the effect of augmented reality without changing the shape of the frame and the weight of the glasses as much as possible, is an important issue in this field.

At present, most AR glasses place the display screen on both sides of the lens, which is convenient for installing the display screen, but the distance from the light to the position where the human eye looks directly will increase, and thicker lenses are needed to achieve good aberration correction. . In order to switch the transparent optical state of the lens (used by general glasses) and the state of augmented reality (activate the display screen and emit image light), most of the current light is introduced into the human eye by means of diffraction or grating, but this will make The optical system is more complex and cannot achieve the purpose of thin and light.

Therefore, the present invention proposes an optical system with augmented reality in view of the lack of the above-mentioned conventional technology and the future demand. The specific structure and its implementation will be described in detail below:

The main purpose of the present invention is to provide an optical system with augmented reality. The transmitted light is reflected three times in the light guide element without using optical principles such as grating, diffraction, and scattering, so that the lens can simultaneously correct the diopter of the eye and augmented reality effects.

Another object of the present invention is to provide an augmented reality optical system, which arranges the display screen above the light guide element, shortens the distance from the incident surface to the second reflective surface, so as to achieve the effect of thinning the lens.

In order to achieve the above object, the present invention provides an optical system with augmented reality, including: a display screen emitting light; The top end is adjacent to one of the reflective surfaces, the outgoing reflective surface, where the outgoing reflective surface is the surface opposite to a human eye, and the incident surface is set corresponding to the display screen, so that light enters the light guide element from the incident surface and passes through the light guide element After being reflected three times by the reflective surface, the light is guided into human eyes from the outgoing reflective surface.

According to an embodiment of the present invention, the incident surface is an inclined surface.

According to an embodiment of the present invention, the reflective surface further includes a first reflective surface and a second reflective surface, the first reflective surface is opposite to the outgoing reflective surface, wherein the outgoing reflective surface is a surface close to the human eye, and the first reflective surface is The surface away from human eyes, the second reflective surface is arranged at the bottom of the light guide element.

According to an embodiment of the present invention, after the light passes through the incident surface, it is reflected by the first reflective surface, the outgoing reflective surface and the second reflective surface in sequence, and then enters the human eye.

According to an embodiment of the present invention, the upper half of the outgoing reflective surface is used to reflect the light reflected by the first reflective surface to the second reflective surface, and the light reflected by the second reflective surface is emitted from the lower half of the outgoing reflective surface light guide element.

According to an embodiment of the present invention, the light is totally reflected by the first reflective surface to the outgoing reflective surface, and the outgoing reflective surface completely reflects the light totally reflected by the first reflective surface again.

According to an embodiment of the present invention, the second reflective surface is provided with a partially penetrating and partially reflective coating, and the light reflected from the outgoing reflective surface is partially penetrating and partially reflected through the second reflective surface, wherein the partially reflected light from the second reflective surface The light will pass through the exit reflective surface to reach the human eye.

According to an embodiment of the present invention, the second reflective surface is an inclined surface.

According to an embodiment of the present invention, the first reflective surface and the outgoing reflective surface are axisymmetric curved surfaces, and the symmetry axes of the first reflective surface and the outgoing reflective surface are arranged coaxially.

According to an embodiment of the present invention, the incident surface and the reflective surface are one of spherical, aspheric or flat.

，其中C為曲率半徑的倒數。 According to an embodiment of the present invention, when the incident surface and the reflecting surface are spherical,

, where C is the reciprocal of the radius of curvature.

，其中A、B、C、D、E等為非球面公式中之參數，C為曲率半徑的倒數，K為圓錐係數。 According to an embodiment of the present invention, when the incident surface and the reflective surface are aspherical,

, where A, B, C, D, E, etc. are the parameters in the aspheric formula, C is the reciprocal of the radius of curvature, and K is the conical coefficient.

According to an embodiment of the present invention, when the incident surface and the reflective surface are planes, Z=0.

According to the embodiment of the present invention, the matching of the curvature of the first reflective surface and the outgoing reflective surface makes the light guide element have a diopter, and the range of the diopter is between plus and minus 8 degrees.

，從顯示屏的中心入射第一反射面的光線的入射角為

，光學系統符合

。 According to an embodiment of the present invention, the angle between the display screen and a Y axis is

, the incident angle of the light incident on the first reflective surface from the center of the display screen is

, the optical system complies with

.

。 According to the embodiment of the present invention, the refractive index of the light guide element is n ₁ , the radius of curvature of the first reflective surface is R _S1 , the radius of curvature of the outgoing reflective surface is R _S2 , and the optical system conforms to

.

。 According to the embodiment of the present invention, the height of light incident on the first reflective surface at the center of the display screen is H _S1 , the radius of curvature of the first reflective surface is R _S1 , and the optical system conforms to

.

According to an embodiment of the present invention, the light guide element and an auxiliary lens are combined into a lens, and the second reflective surface is adjacent to the auxiliary lens.

According to an embodiment of the present invention, the shape of the lens conforms to the frame of an AR glasses.

The present invention provides an optical system with augmented reality, which can be applied to myopia glasses, plano glasses or hyperopia glasses, so that these three kinds of glasses can also have the effect of augmented reality, allowing users to wear them conveniently. In addition, through the design of setting the display screen above the lens, the thickness of the light guide element can still achieve the effect of augmented reality, making the overall optical system thinner and lighter.

Please also refer to FIG. 1A, FIG. 1B, FIG. 2A and FIG. 2B, wherein FIG. 1A and FIG. 1B are perspective views of the lens 14 of the optical system 10 with augmented reality of the present invention, and FIG. 2A and FIG. 2B is a schematic diagram of the optical path and angle of the optical system 10 with augmented reality of the present invention. The optical system 10 with augmented reality of the present invention includes a display screen 12 and a light guide element 142, wherein the display screen 12 is used to emit light, especially image light including images; the light guide element 142 is sheet-shaped, including An incident surface 162 and a plurality of reflective surfaces, the incident surface 162 is arranged on the top of the light guide element 142, the display screen 12 is arranged opposite to the incident surface 162, the light is emitted from the top of the incident surface 162, and the light enters the light guide from the incident surface 162 downwards Element 142. After being reflected three times in the light guide element 142 , the light is guided into the human eye 18 by the light guide element 142 .

More specifically, the incident surface 162 is an inclined surface, and the display screen 12 is parallel to the incident surface 162 . The reflective surface includes a first reflective surface 164 , an outgoing reflective surface 166 and a second reflective surface 168 . Wherein, the first reflective surface 164 is disposed opposite to the outgoing reflective surface 166 , the outgoing reflective surface 166 is a surface close to the human eye 18 , and the first reflective surface 164 is a surface away from the human eye 18 . The incident surface 162 is adjacent to the first reflective surface 164 and the outgoing reflective surface 166 . Furthermore, the first reflective surface 164 and the outgoing reflective surface 166 are axisymmetric curved surfaces, and the symmetry axes of the first reflective surface 164 and the outgoing reflective surface 166 are arranged coaxially. The outgoing reflective surface 166 is divided into two parts, the upper half is the reflective surface, and the lower half is the outgoing surface. The second reflective surface 168 is disposed at the bottom of the light guide element 142 and is an inclined surface. After passing through the incident surface 162 , the light is reflected by the first reflective surface 164 , the outgoing reflective surface 166 and the second reflective surface 168 in sequence, and then enters the human eye 18 .

The reason why the present invention provides three reflective surfaces is that if there are only two reflections, the thickness of the light guide element 142 needs to be thicker to achieve good aberration correction. If it is reflected three times, the light guide element 142 can be thinner to achieve a good aberration correction effect.

The second reflective surface 168 is provided with a partially penetrating and partially reflective coating (not shown in the figure), so the second reflective surface 168 has the effect of partially penetrating and partially reflecting. When the display screen 12 emits light, the light reaching the second reflective surface 168 will partly pass through the second reflective surface 168 and be directed forward, while part of the light will be reflected toward the human eye 18 . When the display screen 12 is not activated, the human eyes 18 can directly see external images through the first reflective surface 164 or the second reflective surface 168 .

The detailed path of the light is as follows: after the light passes through the incident surface 162 , it is totally reflected by the first reflective surface 164 to the upper half of the outgoing reflective surface 166 . Since the upper half of the outgoing reflective surface 166 is a reflective surface, the light totally reflected by the first reflective surface 164 will be totally reflected again by the upper half of the outgoing reflective surface 166 and reflected to the second reflective surface 168 . When the light reflected by the upper half of the outgoing reflective surface 166 passes through the second reflective surface 168, it will partially penetrate and partially reflect, wherein the light partially reflected by the second reflective surface 168 will pass through the lower part of the outgoing reflective surface 166. The half part reaches the human eye 18, so that the human eye 18 can see the image displayed on the display screen 12 and the external image at the same time, so as to achieve the purpose of augmented reality.

The light guide element 142 and an auxiliary lens 144 are combined into a lens 14 , the second reflective surface 168 at the bottom of the light guide element 142 is adjacent to the auxiliary lens 144 , and combined with the bottom of the light guide element 142 by bonding, bonding or other means. The purpose of providing the auxiliary lens 144 is to make the shape of the lens 14 conform to the frame of an AR glasses. And because the user can also see external images through the auxiliary lens 144 , therefore, the auxiliary lens 144 will be consistent with the light guide element 142 in terms of material selection. Because if the materials of the auxiliary lens 144 and the light guide element 142 are inconsistent, the refractive index is also different, and the user sees the external scene through the lens, and the scene will be discontinuous due to the difference in the optical path difference of the lens. The user can directly wear glasses including the optical system 10 with augmented reality of the present invention, without switching between the original myopia glasses or hyperopia glasses and AR glasses.

，其中C為曲率半徑的倒數。當入射面162、第一反射面164、出射反射面166及第二反射面168為非球面時，具擴增實境之光學系統10符合公式

，其中A、B、C、D、E等為非球面公式中之參數，C為曲率半徑的倒數，K為圓錐係數。當入射面162、第一反射面164、出射反射面166及第二反射面168為平面時，具擴增實境之光學系統10符合公式Z=0。 In the present invention, the incident surface 162 , the first reflective surface 164 , the outgoing reflective surface 166 and the second reflective surface 168 are one of a spherical surface, an aspherical surface or a plane. When the incident surface 162, the first reflective surface 164, the outgoing reflective surface 166 and the second reflective surface 168 are spherical, the optical system 10 with augmented reality satisfies the formula

, where C is the reciprocal of the radius of curvature. When the incident surface 162, the first reflective surface 164, the outgoing reflective surface 166 and the second reflective surface 168 are aspherical, the optical system 10 with augmented reality satisfies the formula

, where A, B, C, D, E, etc. are the parameters in the aspheric formula, C is the reciprocal of the radius of curvature, and K is the conical coefficient. When the incident surface 162 , the first reflective surface 164 , the outgoing reflective surface 166 and the second reflective surface 168 are planes, the optical system 10 with augmented reality satisfies the formula Z=0.

In the present invention, in order to allow the human eye 18 to see the external image through the light guide element 142, that is, the external light will first pass through the first reflective surface 164 and then pass through the outgoing reflective surface 166 to reach the human eye 18, thereby enabling the augmented reality The glasses of the optical system 10 have the effects of AR glasses and myopia glasses, hyperopia glasses or plano glasses. Therefore, by utilizing the curvature matching between the first reflective surface 164 and the outgoing reflective surface 166 , the light guide element 142 has a diopter, and the range of the diopter is between plus and minus 8 degrees.

，從顯示屏12的中心入射第一反射面164的光線的入射角為

，則具擴增實境之光學系統10符合

，可達到良好的像差畸變修正。 In addition, since the display screen 12 is inclined, it is also necessary to define the inclination angle of the display screen 12 and the included angle between the incident on the first reflective surface 164 . Suppose the angle between the display screen 12 and the Y axis is

, the incident angle of light incident on the first reflective surface 164 from the center of the display screen 12 is

, then the optical system with augmented reality 10 satisfies

, can achieve good aberration distortion correction.

，可達到良好的屈光度矯正。 In addition, since light is refracted and reflected inside the light guide element 142 , it is necessary to define the relationship between the refractive index of the light guide element 142 and the curvature radii of the first reflective surface 164 and the outgoing reflective surface 166 . Assuming that the refractive index of the light guiding element 142 is n ₁ , the radius of curvature of the first reflective surface 164 is R _S1 , and the radius of curvature of the outgoing reflective surface 166 is R _S2 , the optical system 10 with augmented reality satisfies

, can achieve good diopter correction.

時，為可達到較大視角及輕薄化的較佳範圍。 Furthermore, the distance (height) between the first surface that the light touches after entering the light guide element 142, that is, the position that touches the first reflective surface 164, and the human eye 18 is also an important parameter, which represents the height of the light guide element. Whether the longitudinal length of 142 is short enough, can not exceed the longitudinal length of general spectacle lens. To adjust the height H _S1 of the light incident on the first reflective surface 164 at the center of the display screen 12 , it is also necessary to adjust the radius of curvature of the first reflective surface to R _S1 . In the present invention, the optical system 10 with augmented reality conform to

, it is a better range that can achieve a larger viewing angle and thinner.

Fig. 3 is a schematic diagram of the application of the optical system with augmented reality of the present invention on glasses. As shown in the figure, the lens 14 is a combination of the light guide element 142 and the auxiliary lens 144 , and the combined size matches the size of the frame 20 . The left and right sides of the mirror frame 20 are respectively provided with a display screen 12 . Wear the glasses shown in Figure 3 on the face, as shown in Figure 4A and Figure 4B. When the user wears the glasses, if the display screen 12 is not activated, they can generally be used as plain glasses, nearsighted glasses or farsighted glasses. When the display screen 12 emits image light, the user can see the augmented reality image.

48.6° 55.0° 53.2° 30.44° 2

54.2° 57.45° 55.4° 48.8° 3 n ₁ 1.543 1.543 1.543 1.543 4 R _S1 -200 無限 -400 -65 4 R _S2 -200 無限 -151 -98 6 H _S1 20.55 20.64 19.65 20.6 表一   公式 第一實施例 第二實施例 第三實施例 第四實施例 1

0.896 0.957 0.960 0.624 2

0 0 0.00224 -0.00281 3

5.87 0 2.81 17.58 表二 Figures 5A to 5D are different embodiments of the lens 14, wherein Figure 5A is the first embodiment, and the lens 14 is a lens of plano glasses. Fig. 5B is the second embodiment, and its lens 14 is also the lens of plano glasses. The 5C figure is the third embodiment, and its eyeglass 14 is the eyeglass of the myopic glasses of-2.25 degree. The 5D figure is the fourth embodiment, and its eyeglass 14 is the eyeglass of the hyperopic glasses of +2.75 degree. The parameters of each embodiment are shown in Table 1, and the optimal values of the corresponding formulas are shown in Table 2: parameter first embodiment second embodiment third embodiment Fourth embodiment 1

48.6° 55.0° 53.2° 30.44° 2

54.2° 57.45° 55.4° 48.8° 3 n ₁ 1.543 1.543 1.543 1.543 4 R _S1 -200 unlimited -400 -65 4 R _S2 -200 unlimited -151 -98 6 H _S1 20.55 20.64 19.65 20.6 Table I formula first embodiment second embodiment third embodiment Fourth embodiment 1

0.896 0.957 0.960 0.624 2

0 0 0.00224 -0.00281 3

5.87 0 2.81 17.58 Table II

To sum up, the optical system with augmented reality provided by the present invention can be applied to myopia glasses, plain vision glasses or hyperopia glasses, so that these three kinds of glasses can also have the effect of augmented reality, making it easy for users to wear them. In addition, since the display screen is generally longer horizontally and shorter vertically, the design of the present invention arranges the display screen above the lens to shorten the height of the light guide element, so that the height and thickness of the light guide element are both light and thin to achieve augmented reality. The effect makes AR glasses thinner and lighter. Furthermore, the optical system does not have any diffraction or interference elements or free-form surfaces, and only uses aspherical surfaces, spherical surfaces or flat surfaces. Therefore, the structure is simple and can achieve good aberration correction, and the manufacturability is high. In terms of functionality, the AR glasses using the optical system of the present invention can meet the requirements of refractive correction at the same time.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Therefore, all equivalent changes or modifications based on the features and spirit described in the scope of the application of the present invention shall be included in the scope of the patent application of the present invention.

10: Optical system with augmented reality 12: Display screen 14: Lens 142: Light guide element 144: Auxiliary lens 162: incident surface 164: the first reflective surface 166: Exit reflective surface 168: Second reflective surface 18: Human eye 20: frame

FIG. 1A and FIG. 1B are perspective views of the lens of the optical system with augmented reality of the present invention. FIG. 2A and FIG. 2B are schematic diagrams of the optical paths and angles of the optical system with augmented reality of the present invention. Fig. 3 is a schematic diagram of the application of the optical system with augmented reality of the present invention on glasses. Fig. 4A and Fig. 4B are schematic diagrams of wearing the glasses in Fig. 3 on a human face. 5A to 5D are schematic diagrams of other embodiments of the optical system with augmented reality of the present invention.

10: Optical system with augmented reality

12: Display screen

142: Light guide element

144: Auxiliary lens

162: incident surface

164: the first reflective surface

166: Exit reflective surface

168: Second reflective surface

18: Human eye

Claims (17)

An optical system with augmented reality, comprising: a display screen emitting light; and a light guide element including an incident surface and a plurality of reflective surfaces, the incident surface is arranged on the top of the light guide element and is connected to the reflective surfaces One of the outgoing reflective surfaces is adjacent to one of the outgoing reflective surfaces, wherein the outgoing reflective surface is the surface opposite to a human eye, and the incident surface is set for the display screen, so that the light enters the light guide element from the incident surface, and the light guide After being reflected three times by the reflective surfaces in the element, the light is introduced into human eyes from the outgoing reflective surface; wherein, the reflective surfaces further include a first reflective surface and a second reflective surface, and the first reflective surface and the The outgoing reflective surfaces are oppositely arranged, wherein the outgoing reflective surface is a surface close to the human eye, the first reflective surface is a surface away from the human eye, the second reflective surface is arranged at the bottom of the light guide element, and the first reflective surface The combination of the reflective surface and the curvature of the outgoing reflective surface makes the light guide element have a diopter, and the range of the diopter is between plus and minus 8 degrees. The optical system with augmented reality according to claim 1, wherein the incident surface is an inclined surface. The optical system with augmented reality as described in Claim 1, wherein after the light passes through the incident surface, it is reflected by the first reflective surface, the outgoing reflective surface and the second reflective surface in sequence, and then guided to the person Eye. The optical system with augmented reality as described in Claim 3, wherein the upper half of the outgoing reflective surface is used to reflect the light reflected by the first reflective surface to the second reflective surface, and the second reflective surface The light reflected by the surface exits the light guide element from the lower half of the outgoing reflective surface. The optical system with augmented reality as described in Claim 1, wherein the light is totally reflected by the first reflective surface to the outgoing reflective surface, and the outgoing reflective surface will carry out the light totally reflected by the first reflective surface again total reflection. The optical system with augmented reality as described in Claim 3, wherein the second reflective surface is provided with a partially penetrating and partially reflective coating, and the light reflected by the outgoing reflective surface is partially transmitted through the second reflective surface Partial reflection, wherein the light partially reflected by the second reflective surface will pass through the outgoing reflective surface to reach human eyes. The optical system with augmented reality according to claim 1, wherein the second reflective surface is an inclined surface. The optical system with augmented reality as described in Claim 1, wherein the first reflective surface and the outgoing reflective surface are axisymmetric curved surfaces, and the symmetry axes of the first reflective surface and the outgoing reflective surface are coaxially arranged. The optical system with augmented reality as described in Claim 1, wherein the incident surface and the reflective surfaces are one of spherical, aspherical or flat surfaces. The optical system with augmented reality as described in Claim 9, wherein when the incident surface and the reflecting surfaces are spherical surfaces,

, where C is the reciprocal of the radius of curvature. The optical system with augmented reality as described in Claim 9, wherein when the incident surface and the reflective surfaces are aspheric surfaces,

( D ) y ¹⁰ +( E ) y ¹² +…, where A, B, C, D, E, etc. are the parameters in the aspheric formula, C is the reciprocal of the radius of curvature, and K is the conical coefficient. The optical system with augmented reality as described in Claim 9, wherein when the incident surface and the reflective surfaces are plane, Z=0. The optical system with augmented reality as described in Claim 1, wherein the angle between the display screen and a Y-axis is θ _p , and the incident angle of light incident on the first reflective surface from the center of the display screen is θ _{S 1} , the optical system complies with

. The optical system with augmented reality as described in Claim 1, wherein the refractive index of the light guide element is n ₁ , the radius of curvature of the first reflective surface is R _S1 , and the radius of curvature of the outgoing reflective surface is R _S2 , the optical system complies with

. The optical system with augmented reality as described in Claim 1, wherein the height of light incident on the first reflective surface at the center of the display screen is H _S1 , the radius of curvature of the first reflective surface is R _S1 , the optical system conform to

. The optical system with augmented reality according to claim 1, wherein the light guide element and an auxiliary lens are combined into a lens, and the second reflective surface is adjacent to the auxiliary lens. The optical system with augmented reality as claimed in claim 16, wherein the shape of the lens matches the frame of an AR glasses.

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