Head-mounted display device and display system thereof
Technical Field
The present invention relates to the field of display systems, and more particularly, to a display system applied to a head-mounted display device.
Background
Related optical technologies of Virtual Reality (VR) and Augmented Reality (AR) have received much attention in recent years, but have been developing at a considerably fast rate; in addition, the product has diverse application potential in real life, and products or services achieved by virtual reality and augmented reality technology can be seen in the fields of entertainment, medicine, home furnishing, military affairs and the like.
Examples of applications for virtual reality and augmented reality include various types of display devices, such as: a near-eye display device or a head-mounted display (HMD). The appearance of the near-eye display device is similar to that of glasses, and may also be called glasses type display, video glasses or head-mounted display device, which mainly comprises a carrying portion and a display system installed in the carrying portion; in order to achieve a good optical effect and to achieve the advantage of light weight, the details of the display system are important in the field.
Display systems, which are currently common and applied to head-mounted display devices, can be roughly classified into a lens type or an optical waveguide type. The lenticular display system essentially involves a complicated arrangement of optical systems and the technical threshold for manufacturing is also high. However, in the case of the optical waveguide type, the image/image generated by the display is conceptually transferred to the human eye by the total reflection principle of light; the head-mounted display device manufactured based on the characteristics can arrange the display aside, thereby greatly reducing the shielding of system components to external light and enabling the display device to be thinner and lighter.
However, in addition, the general optical waveguide type head-mounted display device may require additional processes or components to add the 3D display function; therefore, it can be understood that how to design an optical waveguide display device with 3D display effect in a simpler and lower cost manner is a problem to be solved in the related art of a head-mounted display device.
Disclosure of Invention
This summary is provided to provide a simplified summary of the invention in order to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure and is intended to neither identify key or critical elements of the embodiments nor delineate the scope of the invention.
In view of the above-mentioned technical matters, the inventor of the present invention provides a head-mounted display device and a display system thereof through years of experience in manufacturing and developing related industries, wherein two light guide elements are provided, optical mirrors capable of reflecting visible light with different wavelengths are respectively arranged in the two light guide elements, and a microstructure with a specific angle is arranged between the two light guide elements, so as to manufacture the head-mounted display device with a 3D display effect at a low cost.
Accordingly, in some aspects of the present invention, a display system is provided, which includes a first light guide plate, a second light guide plate and a display; the first light guide plate has a first surface and an opposite second surface, and a first optical lens is further disposed therein. The second light guide plate is connected with the second surface of the first light guide plate through a third surface by a plurality of microstructures, and a second optical mirror is further arranged in the second light guide plate. The display is arranged facing the first surface, and a collimating lens set is arranged between the display and the first surface. The first optical lens and the second optical lens are respectively arranged in the same corresponding area of the first light guide plate and the second light guide plate.
According to some embodiments of the present invention, the first optical mirror and the first surface form a first included angle, the second optical mirror and the third surface form a second included angle, and the first included angle and the second included angle are equal in size.
According to some embodiments of the present invention, each of the plurality of microstructures has a micro-reflective surface, and a base angle is formed between the micro-reflective surface and the second surface, and the base angle is not more than 90 degrees in addition to the first angle or the second angle.
According to some embodiments of the present invention, the first optical mirror is configured to reflect a first light and transmit a second light, and the second optical mirror is configured to reflect the second light; wherein the second light has a longer wavelength than the first light.
According to some embodiments of the present invention, the first light guide plate, the second light guide plate and the plurality of microstructures are made of a material having a refractive index of 1.4 to 1.7.
In some aspects of the present invention, a head-mounted display device is further provided, which includes a head-mounted carrying portion for carrying two display systems symmetrically disposed corresponding to two eyes of a user, wherein the two display systems both include a light guide assembly and a display. The light guide assembly comprises a front light guide plate and a back light guide plate, wherein the front light guide plate and the back light guide plate are arranged close to human eyes, a plurality of microstructures are arranged between the front light guide plate and the back light guide plate, a front optical mirror and a back optical mirror are respectively arranged in the front light guide plate and the back light guide plate, and the front optical mirror and the back optical mirror are respectively arranged in the same corresponding areas in the front light guide plate and the back light guide plate. The display is disposed corresponding to one side of the front light guide plate near the human eye, and a collimating lens set is disposed between the display and the front light guide plate.
According to some embodiments of the present invention, a first angle is formed between the front optical mirror and a side of the front light guide plate close to the human eye, a second angle is formed between the rear optical mirror and a side of the rear light guide plate close to the human eye, and the first angle and the second angle are equal in magnitude.
According to some embodiments of the present invention, each of the plurality of microstructures has a micro-reflective surface, and a base angle between the micro-reflective surface and a side of the front light guiding plate away from the human eye is not more than 90 degrees in addition to the first angle or the second angle.
According to some embodiments of the present invention, the front mirror is configured to reflect a first light and transmit a second light, and the rear mirror is configured to reflect the second light; wherein the second light has a longer wavelength than the first light.
According to some embodiments of the present invention, the front light guide plate, the rear light guide plate and the plurality of microstructures are made of a material having a refractive index of 1.4 to 1.7.
Drawings
In order to make the aforementioned and other objects, features, advantages and embodiments of the invention more comprehensible, the following description is given:
FIG. 1 is a cross-sectional top view of a display system according to an embodiment of the present invention;
FIG. 2 is a top cross-sectional view of a portion of a display system according to an embodiment of the present invention;
FIG. 3 is a top view of a micro-section of a display system according to an embodiment of the present invention;
FIG. 4 is a cross-sectional top view of two display systems according to an embodiment of the present invention;
fig. 5 is a schematic view of a head-mounted display device applying two display systems according to an embodiment of the invention.
Reference numerals
10 display system (first display system)
20 second display system
30 head-mounted display device
100, 100' first light guide plate
120 the first surface
140 second side
150, 150' first optic
200, 200' microstructure
210 front connecting surface
220 lateral surface
230 rear connecting surface
250, 250' micro-reflecting surface
300, 300' second light guide plate
320 the third side
340 the fourth side
500, 500' display
600, 600' human eye
700, 700' collimating lens group
800 head-wearing type bearing part
B1 first ray
B2 second ray
T is total thickness
t is thickness
K is the first light-emitting distance
L is the second light-emitting distance
Angle alpha, alpha': angle
Angle of incidence of beta, beta
Bottom angle of gamma, gamma
Angle between theta 1 and theta 3
D1-D3 directions
In accordance with conventional practice, the various features and elements of the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the particular features and elements of the invention in order to best explain the principles of the invention. Moreover, the same or similar reference numbers will be used throughout the drawings to refer to similar components and parts.
Detailed Description
While the present invention has been described in considerable detail with reference to certain preferred versions and embodiments thereof, it should be understood that the present invention is not limited to the disclosed versions and embodiments, but rather, is capable of other forms. In this specification and the claims that follow, the terms "a" and "an" and "the" are to be construed as a plurality unless the context clearly dictates otherwise. Furthermore, in this specification and the claims that follow, unless otherwise indicated, the term "disposed on" may be considered as directly or indirectly attached or otherwise in contact with a surface of something, the definition of which should be determined from the preceding and following/paragraph terms of this specification and the ordinary knowledge in the art to which this specification belongs.
Although numerical ranges and parameters setting forth the invention are approximate, the numerical values set forth in the specific examples are presented as precisely as possible. Any numerical value, however, inherently contains certain standard deviations found in their respective testing measurements. As used herein, "about" generally refers to actual values within plus or minus 10%, 5%, 1%, or 0.5% of a particular value or range. Alternatively, the term "about" indicates that the actual value falls within the acceptable standard error of the mean, and is considered by one of ordinary skill in the art. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained. At the very least, these numerical parameters are to be understood as meaning the number of significant digits recited and the number resulting from applying ordinary carry notation.
In order to solve the problems found by the inventor of the present invention based on the prior art, the present invention provides a head-mounted display device and a display system thereof, wherein two light guide elements are provided, optical mirrors capable of reflecting visible light with different wavelengths are respectively disposed in the two light guide elements, and a microstructure having a specific angle is disposed between the two light guide elements, so as to manufacture the head-mounted display device with a 3D display effect at a lower cost.
FIGS. 1-2 are diagrams illustrating an embodiment of the present invention; fig. 1 shows a cross-sectional top view of the display system (defined above as the inverse of direction D3 in the figure), while fig. 2 shows a partial cross-sectional top view of the display system. Please refer to fig. 1-2 together. The present invention provides a display system 10 including a first light guide plate 100 having a first surface 120 facing a human eye 600 of a user and a second surface 140 opposite to the first surface, wherein a thickness t is provided between the third surface 320 and the fourth surface 340. A first optical lens 150 is further disposed in the first light guide plate 100, wherein the first optical lens 150 is disposed at an angle α with respect to the first surface 120; more specifically, the first optical mirror 150 is disposed between the first surface 120 and the second surface 140, and the first optical mirror 150 is disposed between the first surface 120 and the second surface 140 in an unspecified manner; for example, the present invention may be embedded, or clamped in a groove, or other conventional forms that can be easily recognized by one skilled in the art.
The display system 10 of the present invention further includes a second light guide plate 300 having a third surface 320 facing the second surface 140 and an opposite fourth surface 340, wherein a thickness t is formed between the third surface 320 and the fourth surface 340. A second optical lens 350 is further disposed in the second light guide plate 300, the second optical lens 350 is disposed at an angle α' with respect to the third surface 320; more specifically, the second optical mirror 350 is disposed between the third surface 320 and the fourth surface 340, and the second optical mirror 350 is disposed between the third surface 320 and the fourth surface 340 in a non-specific manner; for example, the locking mechanism may be a snap-fit type, a groove-snap type, or other conventional types that can be easily recognized by one of ordinary skill in the art. In addition, the first optical lens 150 and the second optical lens 350 are disposed in the same corresponding region of the first light guide plate 100 and the second light guide plate 300.
A plurality of microstructures 200 disposed between the first light guide plate 100 and the second light guide plate 300; more specifically, the plurality of microstructures 200 connect the second face 140 and the third face 320. Each of the plurality of microstructures 200 further includes a micro-reflective surface 250, each of the plurality of microstructures 200 is in contact with air through the micro-reflective surface 250, and a base angle γ is formed between an inner surface (i.e., a surface not in contact with air) of the micro-reflective surface 250 and the second surface 140.
Please refer to fig. 1-2 together. The display system 10 further includes a display 500 and a collimating lens assembly 700; the display 500 is disposed opposite to the first surface 120, and the collimating lens assembly 700 is disposed between the display 500 and the first surface 120. Further, the display 500 generates a first light beam B1 and a second light beam B2, which are collimated by the collimating lens assembly 700, penetrate through the first surface 120 and enter the first light guide plate 100. The first optical mirror 150 is used for reflecting the first light beam B1 and transmitting the second light beam B2, and the second optical mirror 350 is used for reflecting the second light beam B2. Therefore, the first light beam B1 is reflected by the first optical mirror 150 and generates a first total reflection effect on the first surface 120, and the incident angle is β'; the second light B2 penetrates the first optical mirror 150, then penetrates the second surface 140 and the third surface 320, is reflected by the second optical mirror 350, and generates a first total reflection effect on the third surface 320, wherein the incident angle is β; in detail, the wavelength of the second light B2 is greater than that of the first light B1; more specifically, the wavelength of the second light B2 is greater than the wavelength of the first light B2; substantially, the first light B1 has a wavelength of 400 to 550 nm, and the second light B2 has a wavelength of 550 to 800 nm. Further, after the first light beam B1 and the second light beam B2 are totally reflected in the first light guide plate 100 and the second light guide plate 300, the micro-reflective surface 250 destroys the total reflection of the first light beam B1 and the second light beam B2 and makes the two light beams enter the human eye 600 along the direction-D3.
FIG. 3 is a schematic top view of a display system in a micro-scale cross-section, according to one embodiment of the invention. Referring to fig. 1 to 3, each of the plurality of microstructures 200 is observed at a microscopic level, and it can be understood that each of the plurality of microstructures 200 includes a front connecting surface 210, a side surface 220, a rear connecting surface 230, and the micro-reflective surface 250. Wherein the front connecting surface 210 substantially overlaps the second surface 140, and the rear connecting surface 230 substantially overlaps the third surface 320; therefore, the front connecting surface 210 and the micro-reflective surface 250 are preferably disposed in parallel. On the other hand, to achieve the above optical effect, there is a certain correlation between the internal parameters (angle and length, etc.) of the display system 10. The correlation is based on the Law of refraction (Snell's Law) and the Total Internal Reflection (Total Internal Reflection). Specifically, the included angle α and the included angle α' have the same size; the incident angle β and the incident angle β' are also equal in magnitude. Accordingly, in this embodiment, the relationship among the angle α, the incident angle β and the base angle γ is defined by the following equation.
Further, considering that the light generated by the collimating lens assembly 700 has a half viewing angle θ (not shown in the drawings); the half viewing angle θ is specifically 0-30 degrees, which further affects the optical path and the actual parameters of the angle α, the angle of incidence β and the base angle γ. Substantially considering the half-viewing angle θ, the relationship among the angle α, the incident angle β and the base angle γ is defined as shown in the following equation.
Still further, the content according to the present embodiment defines that the first light guide plate 100 has a thickness t, and the second light guide plate 300 also has the same thickness t. In addition, the display system 10 does not include the collimating lens assembly 700 and the display 500, specifically, the total thickness of the first light guide plate 100, the plurality of microstructures 200 and the side of the second light guide plate 300 is the total thickness T. On the other hand, the first surface 120 has a first light-emitting position (not shown) with a first light-emitting distance K from the side where the first optical lens 150 is disposed; the fourth surface 340 has a second light-emitting position (not shown) with a second light-emitting distance L from the side where the second optical lens 350 is disposed. Accordingly, the relationship among the angle α, the incident angle β, the base angle γ, the total thickness T, the first light-exiting distance K and the second light-exiting distance L is defined by the following equation.
More specifically, the length of the thickness t is 1mm to 5mm in terms of an actual product; preferably, the thickness t is 2.5 mm. The side lengths of the first light guide plate 100 and the second light guide plate 300 are substantially the same; in the more detail, and in particular,the length of the first light-emitting device is more than or equal to the first light-emitting distance K; thereby achieving the optical effect of the present invention. For each of the plurality of structures 200, the side surface 220 opposite to the micro-reflective surface 250 also substantially contacts air, and an inner surface (i.e., a non-air-contacting surface) of the side surface 220 and the third surface 320 (overlapping the rear connecting surface 230) form an included angle θ1And forms an included angle theta with the second surface 140 (the front connection surface)2. Besides the bottom angle γ, an included angle θ is formed between the inner surface (i.e. the surface not contacting air) of the micro-reflective surface 250 and the third surface 3203. More specifically, the base angle γ is 55 to 85 degrees; and the included angle theta1And the included angle theta2Such as, but not limited to, 90 degrees.
More specifically, in terms of actual manufacturing process, the plurality of microstructures 200 can be fabricated by etching or laser-related process. The actual process part can be located on the surface of the first light guide plate 100 or the second light guide plate 300, and the manufactured light guide plate is then bonded to another light guide plate that is not processed; in detail, the pitch of each of the plurality of microstructures 200 is 5 to 10 μm; the width of the rear connecting surface 230 is shorter than the width of the front connecting surface 210, and the width of the rear connecting surface 230 is substantially the same as the length of the side surface 220, and is about 5 to 30 μm. On the other hand, in the present embodiment, the first light guide plate 100, the second light guide plate 300 and the plurality of microstructures 200 are made of materials having the same refractive index, which is about 1.45 to 1.70; the material composition is not limited in this case, and thus can be made of different compositions or made of the same composition by integral molding. In addition, the first optical mirror 150 can achieve the effect of reflecting the first light ray B1 and transmitting the second light ray B2 by plating an optical film; the second optical lens 350 can also achieve the effect of reflecting the second light beam B2 through the plated optical film.
FIGS. 4-5 illustrate an embodiment of the present invention; fig. 4 shows a cross-sectional top view of two display systems, and fig. 5 shows a schematic view of a head-mounted display device to which the two display systems of fig. 4 are applied. Please refer to fig. 1-5 together. The invention provides a head-mounted display device 30, which comprises a head-mounted bearing part 800 used for being erected on the head of a human body, wherein the head-mounted bearing part 800 is used for bearing a first display system 10 and a second display system 20 which are respectively corresponding to human eyes 600 and 600' of a user and are symmetrically arranged. Specifically, the head-mounted carrying part 800 may be glasses, eye-mask, helmet or other forms that can be considered by those skilled in the art.
Further, the technical content of the first display system 10 has been presented in the display system of the above embodiment; the second display system 20 is disposed symmetrically to the first display system 10. Accordingly, it can be understood that the first display system 10 and the second display system 20 have the same components and parameter settings. Specifically, the second display system 20 includes a first light guide plate 100 'and a second light guide plate 300', and in the head-mounted display device 30 provided in the present embodiment, the first light guide plates (100 and 100 ') and the second light guide plates (300 and 300') have a front-back position corresponding relationship; in the present embodiment, the direction-D2 is defined as the front. Further, the second display system 20 also includes a first optical mirror 150 ', the second optical mirror 350 ', the plurality of microstructures 200 ', and the like; the definition of the parameters is also the same as that of the first display system 10, and therefore, the description thereof is not repeated.
As can be understood from the above description, the present invention can be manufactured simply and at low cost to make a single display system generate 3D visual effect by shifting different wavelengths; the two display systems with symmetry can further enhance the image misalignment by providing different ratios of colors, thereby providing a realistic 3D effect.
Although the present invention has been described with reference to the above embodiments, it should be understood that the invention is not limited thereto. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Accordingly, the scope of the present invention should be determined from the following claims.