KR20200023966A - 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, provided is the transmission type HMD optical system, which reduces the volume of an optical system to have an appearance design similar to ordinary sunglasses, reduces the weight of the optical system to provide a comfortable fit for users to wear without burdening the large weight, provides an efficient transmission type large-angle optical system means allowing an optical means magnifying an image such as an internal reflection curved mirror to be maximally close to an eye of the user to maximize the size of a virtual screen, and simplifies an assembly process so as to lower 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 fit that the user can comfortably wear without a large weight, and provides an image such as an internal reflection curved mirror. The present invention relates to a transmission-type HMD optical system that provides an efficient transmission type interactive angle optical system means that can maximize the size of the virtual screen by maximizing the optical means to the user's eye as close as possible, and simplifies the assembly process.

Head mounted display (HMD) is a device that enlarges the virtual image emitted from the high-definition ultra-small display placed in close proximity to the eye through the optical system, and the HMD is blocked so that it is provided through this optical system. When only the virtual image is visible, it is called a closed HMD. When the optical system is configured so that the optical system located in front of the user's eyes is composed of transparent or semi-transparent windows so that not only the virtual image but also the external HMD image in front of the user can be superimposed simultaneously. It is called HMD.

HMD optical system requires a range that can provide the same image for both eyes even if the pupils are different from each other. As the size of the exit pupil increases, more users can view the virtual screen comfortably without the inconvenience of cropping the image.However, in order to increase this convenience in a conventional optical system, when the exit pupil is enlarged, it is located in front of the user's eyes. As the size and thickness of the optical system become thicker, the usability becomes inferior, and therefore, especially in the case of the transmissive HMD optical system whose main purpose is external use, it tends to reduce the volume and weight of the optical system by excessively reducing the exit pupil size or reducing the size of the virtual screen. Transmissive HMD Optical Sheath Even though it is able to provide the appropriate virtual screen size so that a sufficient amount of information to be provided with all necessary to provide an easy-to-wear transmissive HMD optical system reduces the volume and weight.

On the other hand, in the case of the transmissive HMD optical system, in order to reduce volume and weight, the refractive index is larger in the material than in the air, so that the virtual screen can be transported with a smaller size than the actual screen size. Light splits the image using the TIR (Total Internal Reflection) principle, which cannot penetrate the surface of the material, transfers the image into the light guide, and then emits the image to the air in front of the user's eyes. Several technologies are introduced.

The conventional see-through optical system uses a half mirror method, in which the polarization splitter is diagonally positioned in the space until the enlarged image reaches the inside of the semi-transparent concave reflector, so that the viewing angle which is the purpose of a typical head mount display is shown. In order to enlarge the FOV or Eye Box, there is a structural problem in which the optical system must be proportionately increased, and in order to enlarge them, the overall size and weight of the apparatus increases, so that the entire face is worn by the user. There is a problem that can be easily felt because it becomes a pressure factor.

In addition, PBS Prism is applied as another conventional conventional see-through optical system, and since the image transmission path uses a medium having a high refractive index such as plastic or glass instead of air, an enlarged image is displayed more than air. It is possible to transmit at a small angle, so it is possible to present a transmissive HMD Optic module having a volume smaller than that of the half mirror method, but the image enlargement is limited, it does not reduce the weight, and the weight is heavier, which may cause inconvenience to users. to be.

Therefore, there is an increasing need for a transmission type HMD optical system that can solve such problems.

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

The present invention is to provide a user with a transmission type HMD optical system having a total reflection structure.

The present invention aims at reducing the volume of the optical system to have an appearance design similar to that of ordinary sunglasses in order to solve the above problems.

In addition, the present invention is to reduce the weight of the optical system to have a means for providing a user can wear comfortably without a large weight burden.

In addition, an object of the present invention is to provide an efficient transmission type interactive angle optical system means that can maximize the size of the virtual screen by as close as possible to the user's eye optical means for enlarging an image, such as an internal reflection curved mirror.

In addition, an object of the present invention is to provide a transmission-type HMD optical system that can simplify the assembly process and lower the mass production cost.

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 that are not mentioned are clearly to those skilled in the art from the following description. It can be understood.

In order to achieve the above technical problem, a transmission type HMD optical system having a total reflection structure related to an embodiment of the present invention includes: a display panel unit; A light guide prism for totally reflecting and transmitting the image light generated by the display panel; A convex curved mirror which changes the polarization direction of the image light transmitted from the light guide prism and is sent out through the enlargement and reflection means; And a concave prism for emitting the image light transmitted from the convex curved mirror to the eyeball direction of the user. It may include.

In addition, the convex surface of the convex curved mirror is half-mirror coated to reflect a part of the virtual image light inwardly and to 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 reflection surface of the light guide prism so as to reflect only a specific polarization component of the image light to be transmitted.

The curvature of the concave exit surface of the concave prism may be concentric with the curvature of the reflective surface of the convex curved mirror.

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

On the other hand, a transmission type HMD optical system having a total reflection structure related to 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 reflecting the beam of the front illumination to form image light; A light guide prism for transmitting the image light generated by the display panel by a method of polarizing reflection and total reflection; A convex curved mirror which changes the polarization direction of the image light transmitted from the light guide prism and is sent out through the enlargement and reflection means; And a concave prism for emitting the image light transmitted from the convex curved mirror to the eyeball direction of the user. It may include.

In addition, the convex surface of the convex curved mirror is half-mirror coated to reflect a part of the virtual image light inwardly 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, PBS films of the same direction may be attached to two image polarization reflecting surfaces of the light guide prism so as to reflect only a specific polarization component of the image light transmitted.

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 curved mirror.

The air guide may further include an air gap between the light guide prism and the convex curved mirror to support total reflection of the virtual image light on the total reflection surface of the light guide prism.

On the other hand, a transmission type HMD optical system having a total reflection structure related to 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 reflecting the beam of the front illumination to form image light; A light guide prism for transmitting the image light generated by the display panel by a method of polarizing reflection and total reflection; A convex curved mirror which changes the polarization direction of the image light transmitted from the light guide prism and is sent out through the enlargement and reflection means; And a prism for emitting the image light transmitted from the convex curved mirror to the eyeball direction of the user. And a compensation lens capable of transmitting an external image without distortion of an image related to the image light.

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

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

The air gap may further include an air gap between the light guide prism and the convex curved mirror to support total reflection of the virtual image light in the total reflection surface of the light guide prism.

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 transmission type HMD optical system having a total reflection structure.

The present invention can reduce the volume of the optical system in order to solve the above-described problems can have an appearance design similar to the general sunglasses.

In addition, the present invention can reduce the weight of the optical system to have a means for providing a user can wear comfortably without a large weight burden.

In addition, the present invention can provide an efficient transmission type interactive angle optical system means that can maximize the size of the virtual screen by the optical means for expanding the image, such as the internal reflection curved mirror as close as possible to the eye of the user.

In addition, the present invention can provide a transmission-type HMD optical system that can simplify the assembly process and lower the mass production cost.

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

In addition, the present invention has a total reflection structure that is an efficient image transmission means, the thinner prism and the internal reflection curved mirror means that can maximize the size of the virtual screen in the state as close as possible to the user's eye, the interactive angle virtual It can be provided to users of transmissive HMD optical systems that can simultaneously view images and external images while increasing usability by reducing volume and weight.

In addition, the present invention can provide a transmission-type HMD optical system that can reduce the production cost by minimizing the bonding coupling of the optical components and simplifying the assembly process using the total reflection principle.

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

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 the angle of 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 circle structure for a transmission-type HMD optical system applied to the present invention.
8 illustrates an example of a transmission-type HMD optical system having a total reflection structure according to another embodiment of the present invention.
FIG. 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 art will be described before describing specific technical features of the present invention.

1 is a view for explaining a conventional see-through optical system using a half mirror method.

The spectacle display device shown in FIG. 1 is disclosed in Korean Patent No. 10-0928226, a display element 10 for emitting image light, a polarization separator 11 for reflecting only a specific polarization among light emitted from the micro display panel, A phase retardation plate 12 for converting the linearly polarized light reflected by the polarization splitter into circularly polarized light or converting the incident circularly polarized light into linearly polarized light, and expanding the circularly polarized light that has passed through the phase retardation plate 12 again. An optical transmissive concave reflector 13 which is sent to the phase retardation plate 12 and an optical open / close switch panel 14 attached to an outer surface of the transflective concave reflector to open and close ambient light; It consists of a system.

The image light generated by the display device 10 by the above configuration is P-wave or S-wave property of the whole image light in the 90-degree direction by the polarization separator 11 disposed at an inclination of 45 degrees to the display device 10. Only 50% of the beams are transmitted or reflected to reach the phase retardation plate 12, and the linearly polarized image light in the phase retardation plate 12 is converted into circularly polarized light and reaches the transflective concave reflector 13 and then is reflected. And the circular polarization state of opposite rotation direction passes through the phase delay plate 12 and the polarization separator 11 to reach the user's eye to view the virtual image enlarged in the transflective concave reflector 13. In addition, since there is no lens that obstructs the field of view, the external image may be simultaneously viewed.

However, since the polarization separator 11 is diagonally positioned in the space until the image enlarged by the transflective concave reflector 13 reaches the inside of the prior art described with reference to FIG. 1, the viewing angle which is the purpose of a conventional head mount display ( In order to enlarge the FOV) or the Eye Box, there is a structural problem that the optical system must be proportionately increased, and in order to enlarge them, the overall size and weight of the apparatus increases, and the user presses the entire face when worn by the user. There is a problem that can be easily felt because it becomes a factor.

Prior art 2

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

2 shows a transmission type HMD optical system using a PBS prism, which is disclosed in US Patent US2010290127. The display device 20 emits image light, and the light disposed on the front of the display panel and emitted from the display. A first prism 21 for injecting light into the optic module, a polarizing beam splitter (PBS) film 211 attached to a slope of the first prism 21, and a second unit integrated on the bottom surface of the PBS film Optical of a transmissive HMD device comprising a prism 22, a phase shift film 221 attached to the second prism with an adhesive, and a convex curved surface 23 coupled to and integrated with a lower surface of the phase shift film 221 to be integrated. It consists of a system.

Image light emitted from the display device 20 by the above configuration is incident to 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 polarization beam PBS film After obtaining the polarization component by the 211 is transmitted to the second prism 22, the polarization direction of the beam is shifted by λ / 4 by the phase shift film 221 is transmitted to the convex curved mirror, When the reflection image 231 coated on the lower surface of the convex surface mirror 23 is returned to the enlarged image obtained through internal reflection, the phase shift film 221 is passed again, and the phase shift is increased by another λ / 4. As a result, the virtual image is enlarged in the direction of the user's eye by reflecting the first image light through the PBS film that does not pass through the PBS film that passed through the initial PBS film. Is provided. In addition, the user can experience augmented reality because the external image can be viewed simultaneously through the combined first prism 21 and the second prism 22.

Since the technique described with reference to FIG. 2 uses a medium having a high refractive index such as plastic or glass, rather than air, the image transmission passage can transmit an enlarged image at an angle less than that of air, thereby reducing the volume of the image transmission passage. Transmissive HMD Optic module can be proposed, but the image enlargement is limited, it does not reduce the weight, but rather the weight is heavier, which may cause inconvenience to users.

Key features of the present invention

The conventional See-through optical system described above uses a half mirror method. In this method, the polarization separator is diagonally positioned in the space until the enlarged image reaches the inside of the semi-transparent concave reflector, and thus, a typical head mounted display In order to enlarge the objective field of view (FOV) or eye box (eye box), there is a structural problem that the optical system must be increased proportionally, and in order to enlarge them, the size and weight of the entire apparatus is increased, so that the face is worn by the user. There is a problem that can be easily felt because it becomes a pressure factor to the whole.

In addition, PBS Prism is applied as another conventional conventional see-through optical system, and since the image transmission path uses a medium having a high refractive index such as plastic or glass instead of air, an enlarged image is displayed more than air. It is possible to transmit at a small angle, so it is possible to present a transmissive HMD Optic module having a volume smaller than that of the half mirror method, but the image enlargement is limited, it does not reduce the weight, and the weight is heavier, which may cause inconvenience to users. to be.

Accordingly, an object of the present invention is to provide a user with a transmission type HMD optical system having a total reflection structure to reduce the volume of the optical system to have an appearance design similar to that of ordinary sunglasses in order to solve the above-mentioned problems.

In addition, the present invention is to reduce the weight of the optical system to have a means for providing a user can wear comfortably without a large weight burden.

In addition, an object of the present invention is to provide an efficient transmission type interactive angle optical system means that can maximize the size of the virtual screen by as close as possible to the user's eye optical means for enlarging an image, such as an internal reflection curved mirror.

In addition, an object of the present invention is to provide a transmission-type HMD optical system that can simplify the assembly process and lower the mass production cost.

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, the HMD optical system having a total reflection structure according to the present invention for achieving the above technical problem includes a display panel unit 30 and a light guide prism which transmits the image light generated in the display panel by total reflection. 31, a convex curved mirror 32 for changing the polarization direction of the image transmitted from the light guide prism and returning the image by using the enlargement and reflection means, and a concave prism 33 for emitting the image in the direction of the eyeball of the user. ) May be included.

In addition, the convex surface 322 of the convex curved mirror 32 has a half mirror coating to reflect a part of the virtual image light inwardly and transmit a part of the external image light, and the other plane 321 has a lambda / 4. Phase shift film may be attached.

In addition, a PBS film may be attached to the image polarization reflecting surface 311 of the light guide prism 31 so as 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 seen clearly.

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 the virtual image light occurs smoothly on the total reflection surface 311 of the light guide prism 31.

The image light generated by the display device 30 by the above configuration is incident to the light guide prism 31 and totally reflected by the total reflection surface 311, and is then identified by the PBS film attached to the opposite surface 312. The polarization component can be reflected.

Thereafter, the polarization direction of the beam is shifted by λ / 4 by the phase shift film 321 attached to the plane of the convex curved mirror 32 and transferred to the convex curved mirror 32, and then the convex curved mirror ( Reverting the magnified image obtained through the internal reflection of the half mirror coated on the curved surface 322 of 32) and passing the phase shift film 321 again, the phase shift is made by another λ / 4, In the first PBS reflected image light, the displacement of λ / 2 is finally made to pass through the PBS film instead of reflection, and passes through the concave optical structure and the virtual image enlarged in the direction of the eye of the user through the concave prism 33. External images can be provided simultaneously.

In order to describe the effect of the structure of the present invention in more detail, reference is made to FIGS. 4 to 7.

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

Referring to FIG. 4, the phenomenon and correlation of light refracting when light passes between two media having different refractive indices will be described.

Referring to FIG. 4, when two media having different refractive indices of n1 and n2 contact each other, the path of light passing through the media is bent due to different luminous fluxes, and the degree of rotation is expressed in degrees on the plane of incidence of light. Θ1 and θ2, and Snell's law is defined as in Equation 1 below.

Equation 1

n1 x sin θ1 = n2 x sin θ2

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

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

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

Referring to (a) of FIG. 5, the critical angle refers to the minimum necessary angle for the light not to penetrate through the material to be internally reflected and continue to the inside of the material, and in the case of plastic or glass, normal to the surface. It is about 42 ~ 43 °.

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

Conversely, if the angle of incidence is smaller than the critical angle, light will continue to penetrate through the refracted state of the material surface. Typical products that use total reflection of light include optical fiber and light pipe, and the light guide is a path using total reflection of light.

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

6 is a view illustrating a comparison of the structure of the transmission type HMD optical system of the prior art for making the same viewing angle and the structure of the transmission type HMD optical system to reduce the volume and weight by using the total reflection proposed in the present invention.

In the conventional transmissive HMD optical system shown in FIG. 6A, there is no means for reducing the thickness t1 to provide the same viewing angle (virtual screen size) to the eyeball of the user. In the case of the conventional transmission type HMD optical system presented, as described in FIG. 4, 45 ° reflection is possible because the thickness t1 is reduced by applying the angle of refraction existing between the media having different refractive indices, but the total reflection is not used. The material thickness as much as the width of the beam is necessary.

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

7 is a view for explaining a concentric circle structure for a 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 transmission-type 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 is shown.

In the lens having the general amount of power shown in (a) of FIG. 7, since the parallel beam starting at a long distance is focused by the lens, a beam other than a predetermined focal length positioned directly in front of the lens cannot form an image. Can't see.

However, the window having the curvature of the concentric circle structure shown in FIG. 7 (b) is capable of clear external image recognition because the external image passes through the emission surface and is made of parallel light again.

In addition, (c) of FIG. 7 deforms the window of the concentric circle structure shown in (b) of FIG. 7 and introduces a light guide prism using total reflection inside the concentric circle structure window to simultaneously recognize the external image and the virtual image. So that users can use augmented reality.

3 again, when applying the principles described in FIGS. 4 to 7, the image light generated by the display element 30 is incident on the light guide prism 31 and totally reflected on the total reflection surface 311. The particular polarization component is then reflected by the PBS film attached to the opposite side 312.

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

At this time, since the phase shift is made by another λ / 4, the displacement is finally made by λ / 2 in the initial PBS reflected image light, thereby allowing the PBS film to pass through the non-reflected light, and thus the concave prism 33 is moved. Through this, the virtual image enlarged in the direction of the eyeball of the user and the external image passing through the concentric optical structure are simultaneously provided.

Therefore, 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 the user to wear comfortably without heavy weight, and to enlarge an image such as an internal reflection surface mirror By providing the means as close to the user's eye as close as possible to provide an efficient transmission type interactive angle optical system means that can maximize the size of the virtual screen, and simplify the assembly process can provide a transmission type HMD optical system that can lower the production cost.

Example 2 LCOS Transmissive HMD Optical System

8 illustrates 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 having front illumination.

Specifically, in the embodiment according to the present invention, 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, the display panel A light guide prism 73 which transmits the generated image light by polarization reflection and total reflection, and a convex curved mirror which changes the polarization direction of the image transmitted from the light guide prism and returns the image by using an enlargement and reflection means ( 74, a concave prism 75 that emits an image in an eyeball direction of the user.

In addition, the convex surface 742 of the convex curved mirror 74 has a half mirror coating to reflect a part of the virtual image light inwardly and transmit a part of the external image light, and the other plane 741 has a lambda / 4. Phase shift film may be attached.

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

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 the virtual image light occurs smoothly at the total reflection surface 732 of the light guide prism 73.

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

Thereafter, the light is again reflected by the PBS film attached to the opposite inclined surface 733, and the polarization direction of the beam is shifted 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 the enlarged image obtained through the internal reflection of the half mirror coated on the curved surface 742 of the convex curved mirror 74. If it passes again, the phase shift is made by another λ / 4, so that the overall displacement of the λ / 2 is finally performed in the initial PBS reflected image light, so that the PBS film is not reflected but passed through the concave prism 75. Through the virtual image enlarged in the user's eye direction and the external image passing through the concentric optical structure can be provided at the same time.

Example 3 LCOS Transmissive HMD Optical System

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.

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 having front illumination.

In the embodiment shown in FIG. 9, a front light 70, an illumination prism 71 for injecting the front light, a display panel 72 for reflecting a beam of the front light to form an image, and a display panel generated in the display panel. A light guide prism 73 for transmitting the image light by polarization reflection and total reflection, and a convex curved mirror 74 for changing the polarization direction of the image transmitted from the light guide prism and returning the image by using the enlargement and reflection means. ), A prism 75 that emits an image in the direction of the eyeball of the user, 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 has a half mirror coating to reflect a part of the virtual image light inwardly and transmit a part of the external image light, and the other plane 741 has a lambda / 4. Phase shift film may be attached.

In addition, PBS films in 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 the virtual image light occurs smoothly at 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 to eliminate distortion on the transmitted external image.

According to the above configuration, the image light emitted from the front light 70 and generated by the display element 72 is incident to the light guide prism 31 and is polarized by a PBS film attached to the first inclined surface 731. After the light of the component is reflected, the phase shift totally internally reflected at the total reflection surface 732 and again reflected by the PBS film attached to the opposite inclined surface 733, and is attached to the plane of the convex curved mirror 74. After the polarization direction of the beam is shifted by λ / 4 by the film 741 and transmitted to the convex surface 74, the internal reflection of the half mirror coated on the curved surface 742 of the convex surface 74 is By returning the magnified image obtained through the phase shift film 741 again, the phase shift is performed by another λ / 4, so that the overall displacement of the PBS reflected image light is λ / 2. PB The S film is not reflected but passes through the concave prism 75. The virtual image enlarged in the direction of the eye of the user and the 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, it is possible to reduce the volume of the optical system to have an appearance design similar to that of ordinary sunglasses.

In addition, the present invention can reduce the weight of the optical system to have a means for providing a user can wear comfortably without a large weight burden.

In addition, the present invention can provide an efficient transmission type interactive angle optical system means that can maximize the size of the virtual screen by the optical means for expanding the image, such as the internal reflection curved mirror as close as possible to the eye of the user.

In addition, the present invention can provide a transmission-type HMD optical system that can simplify the assembly process and lower the mass production cost.

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

In addition, the present invention has a total reflection structure that is an efficient image transmission means, the thinner prism and the internal reflection curved mirror means that can maximize the size of the virtual screen in the state as close as possible to the user's eye, the interactive angle virtual It can be provided to users of transmissive HMD optical systems that can simultaneously view images and external images while increasing usability by reducing volume and weight.

In addition, the present invention can provide a transmission-type HMD optical system that can reduce the production cost by minimizing the bonding coupling of the optical components and simplifying the assembly process using the total reflection principle.

Scope of application of the present invention

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

The invention can be embodied in other specific forms without departing from the spirit and essential features of the invention. Accordingly, the above detailed description should not be construed as limited in every respect and should be considered as illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention. The present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. In addition, the claims may be incorporated into claims that do not have an explicit citation relationship in the claims, or may be incorporated into new claims by post-application correction.

Claims (15)

A display panel unit;
A light guide prism for totally reflecting and transmitting the image light generated by the display panel;
A convex curved mirror which changes the polarization direction of the image light transmitted from the light guide prism and is sent out through the enlargement and reflection means; And
A concave prism for emitting the image light transmitted from the convex curved mirror to the eyeball direction of the user; Transmission HMD optical system having a total reflection structure comprising a.
The method of claim 1,
The convex surface of the convex curved mirror has a half mirror coating so as to internally reflect a part of the virtual image light and transmit a part of the external image light,
A transmissive HMD optical system having a total reflection structure, wherein a lambda / 4 phase shift film is attached to the other plane of the convex surface.
The method of claim 1,
On the image polarization reflecting surface of the light guide prism,
A transmission type HMD optical system having a total reflection structure characterized in that a PBS film is attached to reflect only a specific polarization component of transmitted image light.
The method of claim 1,
The curvature of the concave exit surface of the concave prism is concentric with the curvature of the reflection surface of the convex curved mirror, the transmission type HMD optical system having a total reflection structure.
The method of claim 1,
And an air gap between the light guide prism and the convex curved mirror, the air gap supporting total reflection of the virtual image light on the total reflection surface of the light guide prism.
Front lighting;
An illumination prism for incident the front illumination;
A display panel reflecting the beam of the front illumination to form image light;
A light guide prism for transmitting the image light generated by the display panel by a method of polarizing reflection and total reflection;
A convex curved mirror which changes the polarization direction of the image light transmitted from the light guide prism and is sent out through the enlargement and reflection means; And
A concave prism for emitting the image light transmitted from the convex curved mirror to the eyeball direction of the user; Transmission HMD optical system having a total reflection structure comprising a.
The method of claim 6,
The convex surface of the convex curved mirror is half-mirror coated to reflect a part of the virtual image light inwardly and to transmit a part of the external image light.
A transmissive HMD optical system having a total reflection structure, wherein a lambda / 4 phase shift film is attached to the other plane of the convex surface.
The method of claim 6,
And two PBS films in the same direction are attached to two image polarization reflecting surfaces of the light guide prism so as to reflect only a specific polarization component of the transmitted image light.
The method of claim 6,
And the curvature of the concave exit surface of the concave prism is concentric with the curvature of the reflecting surface of the convex curved mirror.
The method of claim 6,
Between the light guide prism and the convex curved mirror,
And an air gap for supporting total reflection of the virtual image light on the total reflection surface of the light guide prism.
Front lighting;
An illumination prism for incident the front illumination;
A display panel reflecting the beam of the front illumination to form image light;
A light guide prism for transmitting the image light generated by the display panel by a method of polarizing reflection and total reflection;
A convex curved mirror which changes the polarization direction of the image light transmitted from the light guide prism and is sent out through the enlargement and reflection means; And
A prism for emitting the image light transmitted from the convex curved mirror to the eyeball direction of the user; And
And a compensation lens capable of transmitting an external image without distorting the image associated with the image light.
The method of claim 11,
The convex surface of the convex curved mirror is half-mirror coated to reflect a part of the virtual image light inwardly and to transmit a part of the external image light.
A transmissive HMD optical system having a total reflection structure, characterized in that the lambda / 4 phase shift film is attached to the convex surface and the other plane.
The method of claim 11,
And two PBS films in the same direction are attached to two image polarization reflecting surfaces of the light guide prism so as to reflect only a specific polarization component of the transmitted image light.
The method of claim 11,
Between the light guide prism and the convex curved mirror,
And an air gap for supporting total reflection of the virtual image light on the total reflection surface of the light guide prism.
The method of claim 11,
The concave curved surface of the compensation lens has a total reflection structure, characterized in that the curvature of the convex surface of the convex curved mirror to eliminate distortion on the transmitted external image.

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