KR102129669B1 - Optical system of see-through head mounted display having total internal reflection element - Google Patents

Abstract

The present invention relates to a transmission type HMD optical system having a total reflection structure. More specifically, the present invention reduces the volume of the optical system to have an appearance design similar to that of ordinary sunglasses, and reduces the weight of the optical system to provide a comfortable fit for a user without burdening a large weight and provides images such as an internal reflection curved mirror. The present invention relates to a transmissive HMD optical system that provides an efficient transmissive large-angle optical system means capable of maximizing the size of a virtual screen by maximizing the optical means to enlarge the user's eye, and simplifying the assembly process, thereby reducing mass production costs.

Description

Transmissive HMD optical system with total reflection structure {Optical system of see-through head mounted display having total internal reflection element}

The present invention relates to a transmission type HMD optical system having a total reflection structure. More specifically, the present invention reduces the volume of the optical system to have an appearance design similar to that of ordinary sunglasses, and reduces the weight of the optical system to provide a comfortable fit for a user without burdening a large weight and provides images such as an internal reflection curved mirror. The present invention relates to a transmissive HMD optical system that provides an efficient transmissive large-angle optical system means capable of maximizing the size of a virtual screen by maximizing the optical means to enlarge the user's eye, and simplifying the assembly process, thereby reducing mass production costs.

Head mount display (HMD) refers to a device that enlarges and views a virtual image emitted from a high-definition, ultra-small display placed at a close distance in front of the eyes through an optical system, and is provided through this optical system because HMD is blocked everywhere When only a virtual image is visible, it is called a closed HMD. If the optical system located in front of the user's eyes is composed of a transparent or translucent window, the optical system is configured to show the HMD external image in front of the user at the same time. Say HMD.

Since HMD optical systems have different pupils with different pupils, they need a range in which the same image can be provided to both eyes, even if the pupils have different pupils in order to be recognized as a commercially useful product. It is defined as, and as the size of the exit pupil increases, more users can comfortably watch the virtual screen without the inconvenience of cutting the image, but in order to increase such convenience in a conventional optical system, if the size of the exit pupil is increased, it is located in front of the user's eyes. As the size or thickness of the optical system becomes thick, the usability decreases. Especially, in the case of the transmissive HMD optical system, which is mainly used for external use, there is a tendency to reduce the volume and weight of the optical system by excessively reducing the size of the exit pupil or reducing the size of the virtual screen. Therefore, it is necessary to provide a transparent HMD optical system that is easy to wear while reducing the volume and weight while providing an appropriate virtual screen size so that a sufficient amount of information can be provided to the transmissive HMD optical system.

On the other hand, in the case of the transmissive HMD optical system, in order to reduce the volume and weight, the refractive index in the material is larger than in air, so the size of the virtual screen can be transferred less than the actual screen size and the image proceeding in the material at an angle greater than the critical angle. To transmit the image into the light guide by dividing the image using the principle of total internal reflection (TIR), the light cannot penetrate the surface of the substance and then emit the image into the air in front of the user's eyes Several techniques are being introduced.

The conventional see-through optical system uses a half mirror method. In this method, the polarization separator is diagonally positioned in a space from the semi-transmissive concave reflector until the enlarged image reaches both sides, and thus the viewing angle, which is the purpose of a typical head-mount display. In order to enlarge (FOV) or eye box, there is a structural problem that the optical system must be proportionally enlarged, and in order to enlarge them, the size and weight of the entire instrument increases, so that the entire face when worn by the user There was a problem that it can easily feel fatigue because it becomes a pressure factor.

In addition, as another conventional conventional see-through optical system, the PBS Prism method is applied. Since this method uses a medium having a large refractive index, such as plastic or glass, rather than air, the image transmission path is larger than the air. Since it can be transmitted at a small angle, it is possible to present a transmissive HMD Optic module that is less bulky than the Half Mirror method, but the image enlargement is limited, it is not possible to reduce the weight, but rather the weight is heavier, which may cause inconvenience to users. to be.

Therefore, there is an increasing need for a transmissive HMD optical system that can solve these problems.

Korea Patent Office Application No. 10-2001-0051585 Korea Patent Office Registration No. 10-0839574

The present invention seeks to provide a user with a transmissive HMD optical system having a total reflection structure.

In order to solve the above-described problem, the present invention aims to reduce the volume of the optical system to have an appearance design similar to that of ordinary sunglasses.

In addition, the object of the present invention is to reduce the weight of the optical system so that the user has a means of providing a comfortable fit without a large weight burden.

In addition, the object of the present invention is to provide an efficient transmissive large-angle optical system means capable of maximizing the size of a virtual screen by bringing the optical means for expanding an image such as an internal reflection curved mirror as close as possible to the user's eyeball.

In addition, an object of the present invention is to provide a transmissive HMD optical system that simplifies the assembly process to lower mass production costs.

On the other hand, the technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned are clearly understood by those skilled in the art from the following description. Will be understandable.

A transmissive HMD optical system having a total reflection structure related to an embodiment of the present invention for achieving the above technical problem, a display panel unit; A light guide prism that totally reflects and transmits image light generated from the display panel; A convex curved mirror that changes the polarization direction of the image light transmitted from the light guide prism and sends it out through an enlargement and reflection means; And a concave prism that emits image light transmitted from the convex curved mirror in a user's eye direction. It may include.

In addition, the convex surface of the convex curvature is half-mirror coated to reflect a part of the virtual image light inside and transmit a part of the external image light, and a λ/4 phase shift film is attached to the other plane of the convex surface. Can be.

In addition, a PBS film may be attached to the image polarization reflective surface of the light guide prism to reflect only a specific polarization component of the transmitted image light.

In addition, the curvature of the concave exit surface of the concave prism may be concentric with the curvature of the reflective surface of the convex curvature.

Further, between the light guide prism and the convex curved mirror, an air gap may be included to support total reflection of virtual image light from the total reflection surface of the light guide prism.

On the other hand, the transmission type HMD optical system having a total reflection structure associated with another embodiment of the present invention for achieving the above technical problem, front illumination; An illumination prism for incident the front illumination; A display panel that reflects the beam of the front light to form image light; A light guide prism for transmitting image light generated from the display panel in a method of polarizing reflection and total reflection; A convex curved mirror that changes the polarization direction of the image light transmitted from the light guide prism and sends it out through an enlargement and reflection means; And a concave prism that emits image light transmitted from the convex curved mirror in a user's eye direction. It may include.

In addition, the convex surface of the convex curved mirror is coated with a half mirror to reflect a part of the virtual image light internally and transmit a part of the external image light, and a λ/4 phase shift film is attached to the other plane of the convex surface. Can be.

In addition, a PBS film in the same direction may be attached to the two image polarization reflecting surfaces of the light guide prism to reflect only a specific polarization component of the transmitted image light.

In addition, the curvature of the concave exit surface of the concave prism may be concentric with the curvature of the reflective surface of the convex curvature.

Further, between the light guide prism and the convex curved mirror, an air gap for supporting total reflection of virtual image light on the total reflection surface of the light guide prism may be further included.

On the other hand, the transmission type HMD optical system having a total reflection structure associated with another embodiment of the present invention for achieving the above technical problem, front illumination; An illumination prism for incident the front illumination; A display panel that reflects the beam of the front light to form image light; A light guide prism for transmitting image light generated from the display panel in a method of polarizing reflection and total reflection; A convex curved mirror that changes the polarization direction of the image light transmitted from the light guide prism and sends it out through an enlargement and reflection means; And a prism that emits image light transmitted from the convex curved mirror in the direction of the user's eyeball. And a compensation lens capable of transmitting an external image without distortion of an image associated with the image light.

In addition, the convex surface of the convex curved mirror is coated with a half mirror to reflect a part of the virtual image light inside and transmit a part of the external image light, and a λ/4 phase shift film is attached to the other surface of the convex surface. Can be.

In addition, a PBS film in the same direction may be attached to the two image polarization reflecting surfaces of the light guide prism to reflect only a specific polarization component of the transmitted image light.

In addition, between the light guide prism and the convex curved mirror, an air gap supporting total reflection of virtual image light on the total reflection surface of the light guide prism may be further included.

In addition, the concave curved surface of the compensation lens may form the same curvature as the convex surface of the convex curved mirror in order to eliminate distortion on the transmitted external image.

The present invention can provide a user with a transmissive HMD optical system having a total reflection structure.

In order to solve the above-described problem, the present invention can reduce the volume of the optical system to have an appearance design similar to that of general sunglasses.

In addition, the present invention can reduce the weight of the optical system so that the user has a means of providing a comfortable fit without a large weight burden.

In addition, the present invention can provide an efficient transmissive large-angle optical system means capable of maximizing the size of a virtual screen by bringing an optical means for expanding an image such as an internal reflection curved mirror as close as possible to the user's eye.

In addition, the present invention can provide a transmissive HMD optical system that simplifies the assembly process and lowers the mass production cost.

In particular, the present invention can provide a user with a transmissive HMD optical system having a total reflection structure.

In addition, the present invention has a total reflection structure, which is an efficient image transmission means, and has a thinner prism and an internal reflection curved mirror means capable of maximizing the size of the virtual screen in the state as close as possible to the user's eyeball. While simultaneously viewing the image and the external image, it can be provided to users of the transmission HMD optical system with improved usability to greatly expand the application field by reducing the volume and weight.

In addition, the present invention can provide a transmissive HMD optical system that minimizes the bonding and coupling of optical components by using the total reflection principle and simplifies the assembly process, thereby reducing mass production cost.

On the other hand, the effects that can be obtained in the present invention are not limited to the above-mentioned effects, and the other effects that are not mentioned will be clearly understood by those skilled in the art from the following description. Will be able to.

1 is a view for explaining a conventional See-through optical system using a Half Mirror method.
2 is a view for explaining a conventional See-through optical system using a PBS Prism method.
Figure 3 shows an example of a transmission type HMD optical system having a total reflection structure proposed by the present invention.
4 is a view for explaining the angle of incidence and refraction in relation to the present invention.
5 is a view for explaining the total reflection structure applied to the present invention.
6 is a view for explaining the total reflection structure for reducing the volume and weight according to the present invention.
7 is a view for explaining a concentric structure for a transmission type HMD optical system applied to the present invention.
8 shows an example of a transmission type HMD optical system having a total reflection structure according to another embodiment of the present invention.
9 illustrates an example of a transmission type HMD optical system having a total reflection structure according to another embodiment of the present invention described with reference to FIG. 8.

Prior art 1

Prior to describing the specific technical features of the present invention, the prior art will be described.

1 is a view for explaining a conventional See-through optical system using a Half Mirror method.

The spectacle-type display device shown in FIG. 1 was published in Korean patent 10-0928226, a display element 10 emitting image light, and a polarization separator 11 reflecting only specific polarized light from the micro display panel, The phase retardation plate 12 for converting the linearly polarized light reflected from the polarization separator into circularly polarized light or changing the incident circularly polarized light into linearly polarized light, and expanding the circularly polarized light passing through the phase retardation plate 12 again Optical of HMD device including a semi-transmissive concave reflector 13 sent to the phase retardation plate 12 and an optical switch panel 14 attached to the outer surface of the semi-transmissive concave reflector to open and close the ambient light It consists of a system.

The image light generated by the display element 10 by the above-described configuration is P-wave or S-wave property among the entire image light in the direction of 90 degrees by the polarization separator 11 disposed at an angle of 45 degrees to the display element 10 Only 50% of the beam is transmitted or reflected to reach the phase retardation plate 12, and the image light linearly polarized in the phase retardation plate 12 is changed to circularly polarized light, and then reflected after reaching the transflective concave reflector 13 It becomes a circularly polarized state in which the rotation direction is reversed, and passes through the phase retardation plate 12 and the polarization separator 11 again to reach the user's eyes to view the enlarged virtual image in the transflective concave reflector 13 It is possible to see the external image at the same time because there is no lens obstructing the field of view in the component.

However, in the prior art described with reference to FIG. 1, since the polarization separator 11 is positioned diagonally in a space from the transflective concave reflector 13 to reach both sides, the viewing angle (which is the purpose of a typical headmount display) In order to enlarge the FOV or the Eye Box, there is a structural problem that the optical system must be proportionally enlarged, and in order to enlarge them, the size and weight of the entire instrument increases, and when worn by the user, the entire face is compressed. As a factor, there is a problem that fatigue can be easily felt.

Prior art 2

2 is a view for explaining a conventional See-through optical system using a PBS Prism method.

The picture shown in FIG. 2 relates to a transmissive HMD optical system using a PBS prism, published as US Patent US2010290127, a display element 20 that emits image light, and light that is disposed on the front surface of the display panel and exits the display The first prism 21 to be incident on the inside of the Optic module, the PBS (Polarizing Beam Splitter) film 211 attached to the slope of the first prism 21, and the second coupled to the lower surface of the PBS film Optics of a transmissive HMD device including a prism 22, a phase shift film 221 attached to the second prism with an adhesive, and a convex curved mirror 23 integrated with the bottom surface of the phase shift film 221 It consists of a system.

By the above-described configuration, the image light emitted from the display element 20 is incident on the Optic module through the first prism, and is attached to the slope of the first prism 21 to select and transmit only a specific polarized beam. After obtaining the polarization component by (211) is transmitted to the second prism 22, the polarization direction of the beam is displaced by λ/4 by the phase shifting film 221 is transferred to the convex curved mirror, When the magnified image obtained through internal reflection is returned from the reflective surface 231 coated on the lower surface of the convex curved mirror 23 and passed through the phase shifting film 221 again, the phase shift by another λ/4 Since it is made, a displacement of λ/2 is finally made in the first PBS-passing image light, and the virtual image enlarged in the direction of the user's eye is provided by reflecting the PBS film through which the first-image light did not pass. In addition, since the external image can be simultaneously viewed through the combined first prism 21 and second prism 22, the user can experience augmented reality.

The technique described with reference to FIG. 2 uses a medium having a large refractive index, such as plastic or glass, rather than air, as the image transmission path, so that the enlarged image can be delivered at an angle less than that of air, which is less bulky than the technique presented in FIG. 1. Although it is possible to present a transmissive HMD Optic module, the disadvantage is that the enlargement of the image is limited, it is not possible to reduce the weight, but rather the weight is heavier, which may cause inconvenience to users.

Key features of the invention

The above-described conventional See-through optical system uses a Half Mirror method, in which a polarization separator is diagonally positioned in a space from the semi-transmissive concave reflector until the enlarged image reaches both sides of the conventional head-mount display. In order to enlarge the objective viewing angle (FOV) or eye box (Eye Box), there is a structural problem that the optical system must be proportionally enlarged, and in order to enlarge them, the size and weight of the entire instrument increases, so that the face when worn by the user There was a problem that it was easy to feel fatigue because it became a pressure factor in the whole.

In addition, as another conventional conventional see-through optical system, the PBS Prism method is applied. Since this method uses a medium having a large refractive index, such as plastic or glass, rather than air, the image transmission path is larger than the air. Since it can be transmitted at a small angle, it is possible to present a transmissive HMD Optic module that is less bulky than the Half Mirror method, but the image enlargement is limited, it is not possible to reduce the weight, but rather the weight is heavier, which may cause inconvenience to users. to be.

Therefore, in order to solve the above-mentioned problem, the present invention aims to reduce the volume of the optical system and have an appearance design similar to that of general sunglasses by providing a transmissive HMD optical system having a total reflection structure to a user.

In addition, the object of the present invention is to reduce the weight of the optical system so that the user has a means of providing a comfortable fit without a large weight burden.

In addition, the object of the present invention is to provide an efficient transmissive large-angle optical system means capable of maximizing the size of a virtual screen by bringing the optical means for expanding an image such as an internal reflection curved mirror as close as possible to the user's eyeball.

In addition, an object of the present invention is to provide a transmissive HMD optical system that simplifies the assembly process to lower mass production costs.

Regarding the transmission type HMD optical system proposed by the present invention, exemplary embodiments will be described below with reference to the drawings.

Example 1-OLED transmissive HMD optical system

Figure 3 shows an example of a transmission type HMD optical system having a total reflection structure proposed by the present invention.

Referring to FIG. 3, a transmissive HMD optical system having a total reflection structure of the present invention for achieving the above technical problem is a display panel unit 30, a light guide prism for transmitting image light generated in the display panel in a total reflection method (31), a convex curved mirror (32) for changing the polarization direction of the image transmitted from the light guide prism and returning the image using a magnification and reflection means, a concave prism (33) for emitting the image in the user's eye direction ).

In addition, the convex surface 322 of the convex curved mirror 32 is coated with a half mirror to reflect a part of the virtual image light inside and transmit a portion of the external image light, and the other plane 321 has λ/4 A phase shift film may be attached.

In addition, a PBS film may be attached to the image polarization reflective surface 311 of the light guide prism 31 to reflect only a specific polarization component of the transmitted image light.

In addition, the curvature of the concave exit surface 331 of the concave prism 33 may be concentric with the curvature of the reflective surface 322 of the convex curved mirror 32 so that the external image can be clearly seen.

In addition, an air gap may be provided between the light guide prism 31 and the convex curved mirror 32 so that total reflection of virtual image light occurs smoothly on the total reflection surface 311 of the light guide prism 31.

The image light generated by the display element 30 by the above configuration is specified by the PBS film attached to the opposite surface 312 after being incident on the light guide prism 31 and totally reflected on the total reflection surface 311. The polarization component can be reflected.

Thereafter, the polarization direction of the beam is displaced by λ/4 by the phase shift film 321 attached to the plane of the convex curved mirror 32 and then transferred to the convex curved mirror 32, followed by the convex curved mirror ( When the image regained through internal reflection of the half mirror coated on the curved surface 322 of 32) is returned again and passed through the phase shifting film 321 again, phase shifting occurs by another λ/4, so that The displacement of λ/2 is finally made in the first PBS reflection image light, so that the PBS film passes through the concave prism 33 through the concave prism 33 and passes through the concentric optical structure and the virtual image enlarged in the user's eye direction. External images can be provided simultaneously.

To more specifically describe the effects of the structure of the present invention, refer to FIGS. 4 to 7.

First, FIG. 4 is a view for explaining an incident angle and a refraction angle in relation to the present invention.

Referring to FIG. 4, when light passes between two media having different refractive indices, a phenomenon and correlation of light refraction are described.

Referring to FIG. 4, when two different media having refractive indices of n1 and n2 are in contact, the path of light passing through the media is curved because the light flux is different for each media, and the degree of 휜 is expressed as an angle on the plane of incidence of light. When it is θ1 and θ2, Snell's law is defined as in Equation 1 below.

Equation 1

n1 x sin θ1 = n2 x sin θ2

(n1, n2: refractive index of two media, θ1: incident angle, θ2: refractive angle)

Next, Figure 5 is a view for explaining the total reflection structure applied to the present invention.

Referring to FIG. 5, the phenomenon in which light continues to proceed by total reflection inside the material or penetrates the surface and is discharged to the outside of the material is described.

Referring to (a) of FIG. 5, a critical angle refers to a minimum angle required for light to be transmitted through the material and not to be transmitted through the material, and is a normal angle perpendicular to the surface in the case of plastic or glass. It is about 42 to 43°.

As shown in (a) and (b) of FIG. 5, if the incident angle is greater than the critical angle, the light hitting the surface of the material is not transmitted outside the surface and reflects inside the material, which is total internal reflection (TIR) ).

Conversely, if the angle of incidence is less than the critical angle, light will penetrate the surface of the material and be transmitted in a refracted state to continue. Typically, products that use the total reflection phenomenon of light include optical fibers and optical pipes, and the passage using total reflection of light is called light guide.

In addition, Figure 6 is a view for explaining the total reflection structure for reducing the volume and weight according to the present invention.

FIG. 6 is a diagram illustrating the structure of a transmissive HMD optical system of the prior art for making the same viewing angle and the structure of a transmissive HMD optical system for reducing volume and weight by using total reflection suggested by the present invention.

In the conventional transmissive HMD optical system shown in FIG. 6(a), there is no means to reduce the thickness t1 in order to provide the same viewing angle (virtual screen size) to the user's eye, and in FIG. 6(b) In the case of the proposed conventional transmission type HMD optical system, as described in FIG. 4, it has a means to reduce the thickness t1 to t2 by applying the refractive angle existing between different refractive index media, but does not use total reflection. The material thickness as much as the width of the beam for is essential.

On the other hand, since the optical system structure shown in FIG. 6(c) uses the total reflection principle described in FIG. 5, the angle of the reflective inclined surface can be lowered to a minimum level according to the viewing angle, so the thickness is significantly thinner than that of the conventional optical system. (t3) In addition to providing an optical system, it is possible to maximize a viewing angle by minimizing the distance to the reflective surface for final magnification of the user's eyeball.

7 is a view for explaining the concentric structure for the transmission type HMD optical system applied to the present invention.

Referring to FIG. 7, a window principle of a concentric circle structure for establishing a transmissive HMD optical system for recognizing an external image and a structure combined with a light guide prism by applying this principle in the present invention are shown.

In the lens having the general amount of power shown in FIG. 7(a), since a parallel beam starting from a long distance is focused by the lens, a beam other than a predetermined focal length located directly in front of the lens does not form an image, so an external image Can not see

However, the window having the curvature of the concentric circle structure shown in FIG. 7B is able to recognize a clear external image because the external image passes through the emission surface and is made of parallel light again.

In addition, FIG. 7(c) can simultaneously recognize an external image and a virtual image by transforming the window of the concentric circle structure shown in FIG. 7(b) to introduce a light guide prism using total reflection inside the concentric circle structure window. This allows users to use augmented reality.

Returning to FIG. 3 again, when applying the principle described in FIGS. 4 to 7, the image light generated by the display element 30 enters the light guide prism 31 and is totally reflected by the total reflection surface 311 Then, a specific polarization component is reflected by the PBS film attached to the opposite surface 312.

Thereafter, the polarization direction of the beam is displaced by λ/4 by the phase shift film 321 attached to the plane of the convex curved mirror 32 and then transferred to the convex curved mirror 32, followed by the convex curved mirror ( The enlarged image obtained through internal reflection of the half mirror coated on the curved surface 322 of 32) is returned again to pass the phase shift film 321 again.

At this time, since the phase shift is performed by λ/4 again, a displacement of λ/2 is finally made in the first PBS reflected image light to pass the PBS film instead of reflection, and the concave prism 33 is Through this, the virtual image enlarged in the direction of the user's eyeball and the external image passing through the concentric optical structure are simultaneously provided.

Accordingly, the present invention reduces the volume of the optical system to have an appearance design similar to that of ordinary sunglasses, and reduces the weight of the optical system to provide a comfortable fit for a user without burdening a large weight and enlarges an image such as an internal reflection curved mirror. It is possible to provide an efficient transmissive large-angle optical system means capable of maximizing the size of a virtual screen by bringing the means as close as possible to the user's eye, and to provide a transmissive HMD optical system that simplifies the assembly process and lowers production costs.

Example 2-LCOS Transmission HMD Optical System

8 shows an example of a transmission type HMD optical system having a total reflection structure according to another embodiment of the present invention.

Another embodiment of a transmissive HMD optical system having a total reflection structure of the present invention shown in FIG. 8 relates to a transmissive HMD optical system having a total reflection structure using an LCOS display with front illumination.

Specifically, in the embodiment according to the present invention, the front illumination 70, the illumination prism 71 for incident the front illumination, the display panel 72 to form an image by reflecting the beam of the front illumination, in the display panel A light guide prism 73 that transmits the generated image light in a method of polarizing reflection and total reflection, and a convex curved mirror that changes the polarization direction of the image transmitted from the light guide prism and returns the image using magnification and reflection means ( 74), it may include a concave prism 75 for emitting the image in the user's eye direction.

In addition, the convex surface 742 of the convex curved mirror 74 is coated with a half mirror to reflect a portion of the virtual image light internally and transmit a portion of the external image light, and λ/4 is applied to the other plane 741. A phase shift film may be attached.

In addition, PBS films of the same direction may be attached to the two image polarization reflecting surfaces 731 and 733 of the light guide prism 73 so as to reflect only a specific polarization component of transmitted image light.

In addition, the curvature of the concave exit surface 751 of the concave prism 75 may form a concentric circle with the curvature of the reflective surface 742 of the convex curved mirror 74 so that the external image can be clearly seen.

In addition, an air gap may be provided between the light guide prism 73 and the convex curved mirror 74 so that total reflection of virtual image light is smoothly generated on the total reflection surface 732 of the light guide prism 73.

By the above configuration, the image light emitted from the front light 70 and generated by the display element 72 enters the light guide prism 31 and is specified polarized by the PBS film attached to the first inclined surface 731. After the light of the component is reflected, it is totally internally reflected on the total reflection surface 732.

Then, it is reflected again by the PBS film attached to the opposite inclined surface 733, and the polarization direction of the beam is displaced by λ/4 by the phase shift film 741 attached to the plane of the convex curved mirror 74. After being transferred to the convex curved mirror 74, the phase shift film 741 is returned by returning an enlarged image obtained through internal reflection of the half mirror coated on the curved surface 742 of the convex curved mirror 74. When passing again, the phase shift is made by λ/4 once again, so that the displacement of λ/2 is finally made in the first PBS reflected image light to pass the PBS film instead of reflection, and the concave prism 75 Through this, a virtual image enlarged in the direction of the user's eyeball and an external image passing through the concentric optical structure may be simultaneously provided.

Example 3-LCOS Transmission HMD Optical System

On the other hand, Figure 9 shows an example of a transmission type HMD optical system having a total reflection structure according to another embodiment of the present invention described in FIG.

Another embodiment of a transmissive HMD optical system having a total reflection structure of the present invention shown in FIG. 9 relates to another transmissive HMD optical system having a total reflection structure using an LCOS display with front illumination.

In the embodiment shown in FIG. 9, the front light 70, the illumination prism 71 for injecting the front light, the display panel 72 for reflecting the beam of the front light to form an image, and generated in the display panel A light guide prism (73) for transmitting image light in a manner of polarizing reflection and total reflection, and a convex curved mirror (74) that changes the polarization direction of the image transmitted from the light guide prism and returns the image using magnification and reflection means. ), a prism 75 that emits an image in the direction of the user's eye, and a compensation lens 76 that can transmit an external image without distortion of the image.

In addition, the convex surface 742 of the convex curved mirror 74 is coated with a half mirror to reflect a portion of the virtual image light internally and transmit a portion of the external image light, and λ/4 is applied to the other plane 741. A phase shift film may be attached.

In addition, PBS films of the same direction may be attached to the two image polarization reflecting surfaces 731 and 733 of the light guide prism 73 so as to reflect only a specific polarization component of the transmitted image light.

In addition, an air gap may be provided between the light guide prism 73 and the convex curved mirror 74 so that total reflection of virtual image light is smoothly generated on the total reflection surface 732 of the light guide prism 73.

In addition, the concave curved surface 761 of the compensation lens 76 may form the same curvature as the convex surface 742 of the convex curved mirror 74 in order to eliminate distortion on the transmitted external image.

By the above configuration, the image light emitted from the front light 70 and generated by the display element 72 enters the light guide prism 31 and is specified polarized by the PBS film attached to the first inclined surface 731. After the light of the component is reflected, the total internal reflection on the total reflection surface 732 is reflected again by the PBS film attached to the opposite inclined surface 733, and the phase shift attached to the plane of the convex curved mirror 74 After the polarization direction of the beam is displaced by λ/4 by the film 741 and transferred to the convex curved mirror 74, the internal reflection of the half mirror coated on the curved surface 742 of the convex curved mirror 74 is reflected. By reverting the magnified image obtained through the above and passing the phase shift film 741 again, another phase shift is made by λ/4, so that a displacement of λ/2 is finally made in the first PBS reflected image light. The PBS film is passed through rather than reflection, and a virtual image enlarged in the user's eye direction through the concave prism 75 and an external image passing through the light guide optical structure and the compensation lens are simultaneously provided.

Effect according to the invention

When the transmissive HMD optical system having the total reflection structure according to the present invention is applied, the volume of the optical system can be reduced to have an appearance design similar to that of general sunglasses.

In addition, the present invention can reduce the weight of the optical system so that the user has a means of providing a comfortable fit without a large weight burden.

In addition, the present invention can provide an efficient transmissive large-angle optical system means capable of maximizing the size of a virtual screen by bringing an optical means for expanding an image such as an internal reflection curved mirror as close as possible to the user's eye.

In addition, the present invention can provide a transmissive HMD optical system that simplifies the assembly process and lowers the mass production cost.

In particular, the present invention can provide a user with a transmissive HMD optical system having a total reflection structure.

In addition, the present invention has a total reflection structure, which is an efficient image transmission means, and has a thinner prism and an internal reflection curved mirror means capable of maximizing the size of the virtual screen in the state as close as possible to the user's eyeball. While simultaneously viewing the image and the external image, it can be provided to users of the transmission HMD optical system with improved usability to greatly expand the application field by reducing the volume and weight.

In addition, the present invention can provide a transmissive HMD optical system that minimizes the bonding and coupling of optical components by using the total reflection principle and simplifies the assembly process, thereby reducing mass production cost.

Scope of application of the present invention

The detailed description of preferred embodiments of the present invention disclosed as described above has been provided to enable those skilled in the art to implement and practice the present invention. Although described above with reference to preferred embodiments of the present invention, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the scope of the present invention. For example, those skilled in the art can use each of the configurations described in the above-described embodiments in a manner of combining with each other. Accordingly, the invention is not intended to be limited to the embodiments presented herein, but rather to give the broadest scope consistent with the principles and novel features disclosed herein.

The present invention may be embodied in other specific forms without departing from the spirit and essential features of the present invention. Accordingly, the above detailed description should not be construed as limiting in all respects and should be considered illustrative. The scope of the invention should be determined by rational interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention. The invention is not intended to be limited to the embodiments presented herein, but rather to give the broadest scope consistent with the principles and novel features disclosed herein. In addition, in the claims, claims that do not have an explicit citation relationship may be combined to constitute an embodiment, or may be included as new claims by amendment after filing.

Claims (15)

In the transmission type HMD optical system,
A display panel unit;
A light guide prism that totally reflects and transmits image light generated from the display panel;
A convex curved mirror that changes the polarization direction of the image light transmitted from the light guide prism and sends it out through an enlargement and reflection means; And
A concave prism that emits image light transmitted from the convex curved mirror in the direction of the user's eyeball; Including,

The convex surface of the convex curved mirror has a partial reflection coating to reflect a part of the virtual image light inside and enlarge, and transmit a part of the external image light,
A λ/4 phase shift film is attached to the other plane of the convex surface,

On the image polarization reflective surface of the light guide prism,
PBS film is attached to reflect only a specific polarization component of transmitted image light,

The curvature of the concave exit surface of the concave prism forms a concentric circle with the curvature of the reflective surface of the convex curvature,

Between the light guide prism and the convex curved mirror, an air gap further supporting total reflection of virtual image light on the total reflection surface of the light guide prism is further included.

The image light totally reflected from the total reflection surface is reflected by a specific polarization component by the PBS film on the polarization reflection surface,

By the λ/4 phase shift film attached to the other plane of the convex surface, the polarization direction of the image light is displaced by λ/4,

The enlarged image light obtained through internal reflection by the partial reflection coating of the convex surface of the image light whose polarization direction is displaced by λ/4 is passed through the λ/4 phase shifting film again, so that the polarization direction is phased by λ/4. Is re-displaced,

The re-displaced enlarged image light passes through the PBS film,

The passed image light is emitted through the concave prism in the direction of the user's eye, so that the virtual image by the passed image light and the external image around the user wearing the transmissive HMD optical system are simultaneously provided to the user And

The air gap,
It does not exist between the λ/4 phase shift film of the convex curved mirror and the convex surface of the convex curved mirror, but is present only between the light guide prism and the λ/4 phase shift film of the convex curved mirror. Transmission HMD optical system.
delete delete delete delete Front lighting;
An illumination prism for incident the front illumination;
A display panel that reflects the beam of the front light to form image light;
A light guide prism for transmitting image light generated from the display panel in a method of polarizing reflection and total reflection;
A convex curved mirror that changes the polarization direction of the image light transmitted from the light guide prism and sends it out through an enlargement and reflection means; And
A concave prism that emits image light transmitted from the convex curved mirror in the direction of the user's eyeball; Including,

The convex surface of the convex curved mirror has a partial reflection coating to reflect a part of the virtual image light inside and enlarge and reflect a part of the external image light,
A λ/4 phase shift film is attached to the other plane of the convex surface,

PBS films of the same direction are attached to the two image polarization reflective surfaces of the light guide prism to reflect only a specific polarization component of the transmitted image light,

The curvature of the concave exit surface of the concave prism forms a concentric circle with the curvature of the reflective surface of the convex curvature,

Between the light guide prism and the convex curved mirror,
Further comprising an air gap supporting the total reflection of the virtual image light occurs in the total reflection surface of the light guide prism,

The image light totally reflected from the total reflection surface is reflected by a specific polarization component by the PBS film on the polarization reflection surface,

By the λ/4 phase shift film attached to the other plane of the convex surface, the polarization direction of the image light is displaced by λ/4,

The enlarged image light obtained through internal reflection by the partial reflection coating of the convex surface of the image light whose polarization direction is displaced by λ/4 is passed through the λ/4 phase shifting film again, so that the polarization direction is phased by λ/4. Is re-displaced,

The re-displaced enlarged image light passes through the PBS film,

The passed image light is emitted through the concave prism in the direction of the user's eye, so that the virtual image by the passed image light and the external image around the user wearing the transmissive HMD optical system are simultaneously provided to the user. ,

The air gap,
It does not exist between the λ/4 phase shift film of the convex curved mirror and the convex surface of the convex curved mirror, but is present only between the light guide prism and the λ/4 phase shift film of the convex curved mirror. Transmission HMD optical system.
delete delete delete delete Front lighting;
An illumination prism for incident the front illumination;
A display panel that reflects the beam of the front light to form image light;
A light guide prism for transmitting image light generated from the display panel in a method of polarizing reflection and total reflection;
A convex curved mirror that changes the polarization direction of the image light transmitted from the light guide prism and sends it out through an enlargement and reflection means; And
A prism for emitting the image light transmitted from the convex curved mirror in the direction of the user's eyeball; And
It includes; a compensation lens capable of transmitting an external image without distortion of the image associated with the image light;

The convex surface of the convex curved mirror is partially coated with a reflection to enlarge a part of the virtual image light and transmit a part of the external image light,
A λ/4 phase shift film is attached to the other surface of the convex surface,

PBS films of the same direction are attached to the two image polarization reflective surfaces of the light guide prism to reflect only a specific polarization component of the transmitted image light,

Between the light guide prism and the convex curved mirror,
Further comprising an air gap supporting the total reflection of the virtual image light occurs in the total reflection surface of the light guide prism,

The concave curved surface of the compensation lens forms the same curvature as the convex surface of the convex curved mirror in order to eliminate distortion on the transmitted external image,

The image light totally reflected from the total reflection surface is reflected by a specific polarization component by the PBS film on the polarization reflection surface,

By the λ/4 phase shift film attached to the other plane of the convex surface, the polarization direction of the image light is displaced by λ/4,

The enlarged image light obtained through internal reflection by the partial reflection coating of the convex surface of the image light whose polarization direction is displaced by λ/4 is passed through the λ/4 phase shifting film again, so that the polarization direction is phased by λ/4. Is re-displaced,

The re-displaced enlarged image light passes through the PBS film,

The passed image light is emitted through the concave prism toward the eyeball of the user, whereby the virtual image by the passed image light and the external image around the user wearing the transmissive HMD optical system are simultaneously provided to the user,

The air gap,
It does not exist between the λ/4 phase shifting film of the convex curved mirror and the convex surface of the convex curved mirror, but is present only between the light guide prism and the λ/4 phase shifting film of the convex curved mirror. Transmission HMD optical system. delete delete delete delete

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