Imaging device to which image display element and extended depth-of-focus contact lens are applied

Abstract

The present invention provides an imaging device for providing an extended depth-of-focus image. The device comprises: an image display element which generates light for displaying an image; a polarizing plate arranged to be adjacent to the image display element so as to polarize the light; and a circular contact lens, which is arranged to be spaced apart from the polarizing plate and can be worn on the cornea of a user. Here, the contact lens is composed of a first region, which is arranged at a center part and has a diameter of 2 mm or less, and a second region that excludes the first region, wherein the second region can be composed of a polarizing material orthogonal to the polarization direction of the image-displaying light that passed through the polarizing plate.

Description

An imaging device that uses an image display element and a depth-of-focus extension contact lens

[0001] The present invention relates to an imaging device, and more particularly, to an imaging device that provides an image with an expanded depth of focus by an image display element and a contact lens worn by a user.

[0002] Existing XR (Extended Reality) optical systems are commercialized in the form of AR / VR and MR, providing virtual images as two-dimensional images to a single eye or as three-dimensional images to both eyes. Furthermore, existing 3D display devices also provide different parallaxes to the two eyes to create 3D images.

[0003] However, while existing XR devices and 3D image display devices can provide stereoscopic images due to binocular parallax, they cannot provide information on eye focus adjustment. For this reason, the greater the difference between the depth of the 3D image and the depth of the displayed image or virtual image, the greater the blurriness of the 3D image seen by the user, which deteriorates the 3D image quality. In severe cases, this can lead to physical side effects such as eye fatigue and headaches.

[0004] Therefore, providing focus adjustment information in 3D image display devices and XR devices that provide 3D images is an important function.

[0005] Korean Patent No. 10-1919486 (hereinafter referred to as "Patent Document 1") describes a structure that provides focus adjustment information to the user through a combination of multiple apertures and small lenses. However, this structure suffers from a reduction in resolution at each viewpoint.

[0006] Korean Patent Nos. 10-2284743 (hereinafter referred to as "Patent Document 2") and 10-2297139 (hereinafter referred to as "Patent Document 3") describe specific combinations and arrangements of apertures and optical lenses capable of extending depth of field. Furthermore, they propose regions and conditions for extending depth of field. These conditions were experimentally verified and included in the paper "Extended depth of field in augmented reality," Scientific Reports, 2023.

[0007] Korean Patent No. 10-2489272 (hereinafter referred to as "Patent Document 4") devised a realistic application structure that does not degrade the resolution at each viewpoint compared to previous depth-of-focus expansion structures. However, this structure also increases the overall optical system volume and requires additional components for dynamic apertures linked to eye tracking technology, or for high-speed dynamic apertures utilizing time-division technology.

[0008] Against this backdrop, previous patents and validation papers on depth of focus expansion have confirmed that depth of focus expansion technology can be sufficiently applied to future focus control goals. However, the technologies described in Patent Documents 1 to 4 have the disadvantage of requiring a larger optical system and complex additional technologies, such as eye tracking and dynamic aperture technology, to implement a depth of focus expansion optical system. Therefore, a method for implementing depth of focus expansion with a simpler optical system is needed. Such a simplified optical system can utilize contact lenses worn by the user.

[0009] Korean Patent Publication No. 10-2019-0086514 (hereinafter referred to as "Patent Document 5") devised a structure that electronically adjusts the aperture to correct vision related to myopia, hyperopia, astigmatism, and presbyopia in everyday life. However, this structure limits the area of ​​the user's pupil through which light passes, and light in the remaining pupil area is blocked. This causes the side effect of darkening the external environment when observing the external environment, for example, in a case where the pupil size is 3 mm, external light is reduced to approximately 1 / 9.

[0010] The problem to be solved by the present invention is to provide an imaging device capable of implementing a three-dimensional image by adjusting the focus.

[0011] The present invention discloses an imaging device. The device comprises an image display element that generates light for displaying an image; a polarizing plate that is disposed adjacent to the image display element and polarizes the light; and a circular contact lens that is disposed spaced apart from the polarizing plate and is wearable on the cornea of ​​a user. Here, the contact lens comprises a first region having a diameter of 2 mm or less and disposed in a central portion, and a second region excluding the first region, wherein the second region is composed of a polarizing material that is orthogonal to the polarization direction of light that displays an image passing through the polarizing plate.

[0012] In one example, the first region of the contact lens is a non-polarized light transmitting region.

[0013] According to one example, the first region of the contact lens is composed of a polarizing material, and the polarizing direction of the polarizing material is the same as the polarizing direction of light that displays an image passing through the polarizing plate.

[0014] In one example, the polarization may be linear polarization or circular polarization.

[0015] According to one example, the contact lens may additionally include a polarization direction indicator that indicates the polarization direction.

[0016] In one example, the first region of the contact lens may be configured in an annular shape.

[0017] According to one example, a polarization direction rotation element may be additionally provided adjacent to the polarizing plate.

[0018] According to one example, the polarization direction rotation element can be adjusted so that the polarization direction of the second region of the contact lens worn on the user's cornea and the polarization direction of light passing through the polarization direction rotation element are orthogonal.

[0019] According to one example, a first image (left-eye image) and a second image (right-eye image) are alternately arranged on the image display element, and an optical film is additionally arranged at a predetermined interval on the front surface of the polarizing plate to spatially separate the first image and the second image, so that the first image can be transmitted to a contact lens worn on the user's left eye and the second image can be transmitted to a contact lens worn on the user's right eye.

[0020] In one example, the optical film may be a parallax barrier or a lenticular lens.

[0021] In one example, a near-eye optical element may be additionally positioned adjacent to the polarizing plate to simultaneously view an external object and the image in the contact lens.

[0022] In one example, the near-eye optical element may include a beam splitter and a semi-transmissive concave mirror.

[0023] An imaging device according to one embodiment of the present invention comprises: an image display element that generates light for displaying an image; a polarizing element that is disposed adjacent to the image display element and polarizes the light; and a circular contact lens that is disposed spaced apart from the polarizing element and that can be worn on a user's cornea. Here, the contact lens includes a first region a and a first region b, each having a diameter of 2 mm or less and spaced apart from a predetermined distance in the center, and a second region excluding the first region a and the first region b of the contact lens, the first region a of the contact lens being a first polarization-transmitting region, the first polarization and the second polarization being orthogonal to each other, and the second region of the contact lens being made of an opaque material.

[0024] In one example, the first polarization and the second polarization of the contact lens are linear polarization or circular polarization.

[0025] According to one example, the image display device provides a first parallax image and a second parallax image by time-dividing one frame, and the polarizing device is synchronized with the time division of the image display device to polarize with a first polarization when it is a first parallax image and with a second polarization when it is a second parallax image, so that the first parallax image can be transmitted to the user's pupil through the first a region of the contact lens, and the second parallax image can be transmitted to the user's pupil through the first b region of the contact lens.

[0026] According to an example, the image display element is composed of a plurality of pixels, a first parallax image and a second parallax image are arranged in adjacent pixels, and the polarizing element has a first polarizing area and a second polarizing area alternately arranged.

[0027] The first polarization area of ​​the polarizing element is arranged corresponding to the pixels on which the first parallax image of the image display element is arranged, and the second polarization area of ​​the polarizing element is arranged corresponding to the pixels on which the second parallax image of the image display element is arranged.

[0028] The first parallax image may be transmitted to the user's pupil through the first a region of the contact lens, and the second parallax image may be transmitted to the user's pupil through the first b region of the contact lens.

[0029] According to one example, a polarization direction rotation element may be additionally provided adjacent to the polarizing element.

[0030] According to one example, the polarization direction rotation element can be adjusted so that the polarization direction of the first a region of the contact lens worn on the user's cornea and the first polarization direction of light passing through the polarization direction rotation element are identical, and the polarization direction of the first b region of the contact lens and the second polarization direction of light passing through the polarization direction rotation element are identical.

[0031] According to one example, when the contact lens is worn on a human cornea, a polarization direction indicator may be additionally configured to indicate the polarization direction of the contact lens.

[0032] In one example, the first a region and the first b region of the contact lens may be configured in an annular shape.

[0033] According to one example, a first image (left-eye image) and a second image (right-eye image) are alternately arranged on the image display element, and an optical film is additionally arranged at a predetermined interval in front of the polarizing element to spatially separate the first image and the second image, so that the first image can be transmitted to a contact lens worn on the user's left eye and the second image can be transmitted to a contact lens worn on the user's right eye.

[0034] In one example, the optical film may be a parallax barrier or a lenticular lens.

[0035] In one example, a near-eye optical element may be additionally positioned adjacent to the polarizing element to enable a user wearing the contact lens to view an external object and the image simultaneously.

[0036] In one example, the near-eye optical element may include a beam splitter and a semi-transmissive concave mirror.

[0037] As described above, the imaging device according to the concept of the present invention can enable a user to view a virtual image with a wide depth of focus for a long time without fatigue by wearing a depth-of-focus expanding contact lens on the eyeball without adding an additional bulky optical system or complex device to a glasses-type / autostereoscopic 3D image display device or a near-eye image display device (e.g., extended reality (XR), virtual reality (AR), mixed reality (MR), etc.) without a focus adjustment function. In addition, the imaging device according to the concept of the present invention provides two parallax images to a single pupil of the user's eye by using a glasses-type / autostereoscopic 3D image display device or a near-eye image display device that provides a 3D image by time division or space division and a depth-of-focus expanding contact lens having mutually orthogonal polarizing regions arranged at the center, thereby enabling the user to view a natural 3D image similar to a hologram.

[0038] FIG. 1 is a cross-sectional view showing an example of an imaging device (100) that applies a flat-panel 3D image display device and a depth-of-focus extension contact lens according to the concept of the present invention.

[0039] FIG. 2a and FIG. 2b are a plan view and a cross-sectional view showing a specific example of a contact lens (40) of FIG. 1 worn on a user's eye according to an embodiment of the present invention.

[0040] FIG. 3a and FIG. 3b are a plan view and a cross-sectional view showing an example of a specific shape of a contact lens (40) of FIG. 1 according to an embodiment of the present invention.

[0041] FIG. 4 is a plan view showing an example of a depth-of-focus extended contact lens made of a linear polarizing material, which is an example of the contact lens of FIG. 3a.

[0042] FIG. 5 is a plan view showing a depth of focus extension contact lens composed of a circularly polarizing material as an example of the contact lens of FIG. 3a.

[0043] FIGS. 6A and 6B are plan views of an extended depth of focus contact lens having an additional polarization direction indicator, which is an example of the contact lens of FIG. 3A.

[0044] Fig. 7a is a cross-sectional view showing an example of a polarization direction rotation element provided adjacent to the image display element of Fig. 1. Fig. 7b is a drawing showing a polarization direction changed by the polarization direction rotation element of Fig. 7a.

[0045] FIG. 8a and FIG. 8b are drawings showing an example of a method for optimizing the polarization direction of a virtual image generated by the image display element and polarization direction rotation element of FIG. 7a according to the condition of the contact lens worn by the user.

[0046] FIG. 9 is a cross-sectional view showing an example of an imaging device using a near-eye optical element and a depth-of-focus extension contact lens according to the concept of the present invention.

[0047] FIG. 10 is a cross-sectional view showing an example of an image device using a glasses-type 3D image display device and a depth-of-focus extended contact lens according to the concept of the present invention.

[0048] FIG. 11 is a cross-sectional view showing an example of a flat-panel 3D image display device and an image device using a depth-of-focus extension contact lens according to the concept of the present invention.

[0049] FIG. 12a and FIG. 12b are plan views and cross-sectional views showing a specific example of a contact lens (40) of FIG. 11 worn on a user's eye according to an embodiment of the present invention.

[0050] FIG. 13a and FIG. 13b are plan views and cross-sectional views showing an example of a specific shape of the contact lens of FIG. 11 according to an embodiment of the present invention.

[0051] FIGS. 14a and 14b are plan views of an extended depth of focus contact lens having an additional polarization direction indicator, which is an example of the contact lens of FIG. 13a.

[0052] Figures 15a and 15b are cross-sectional views showing the situation in which the first and second polarizations of the variable polarizing element are changed in a time-division manner through the contact lens of Figure 13a and transmitted to the pupil of the user's eye, respectively.

[0053] Fig. 16 is a cross-sectional view showing an example of an imaging device that implements a multi-viewpoint space division method according to the concept of the present invention.

[0054] FIGS. 17a and 17b are cross-sectional views showing an example of an imaging device that provides two-viewpoint multi-viewpoint images in a time-division manner by applying a near-eye optical element and a depth-of-focus extension contact lens according to the concept of the present invention.

[0055] FIG. 18 is a cross-sectional view showing an example of an imaging device that provides a two-viewpoint super-multi-viewpoint image by spatial division using a near-eye optical element and a depth-of-focus extension contact lens according to the concept of the present invention.

[0056] FIGS. 19a and 19b are plan views and cross-sectional views showing an example of applying an enula aperture to the contact lens of FIGS. 3a and 3b as an embodiment of the present invention.

[0057] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. The advantages and features of the present invention, as well as the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the attached drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in various forms. Rather, the embodiments introduced herein are provided to ensure that the disclosure is thorough and complete and to sufficiently convey the spirit of the present invention to those skilled in the art, and the present invention is defined solely by the scope of the claims. Like reference numerals throughout the specification refer to like elements.

[0058] The terminology used herein is for the purpose of describing embodiments only and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise. The terms "comprises" and / or "comprising" as used herein do not exclude the presence or addition of one or more other components, operations, and / or elements, as well as the elements, operations, and / or components mentioned. In addition, since this is according to a preferred embodiment, reference numerals presented in the order of description are not necessarily limited to that order.

[0059] Furthermore, the embodiments described herein will be described with reference to cross-sectional and / or plan views, which are ideal illustrations of the present invention. In the drawings, the thicknesses of membranes and regions are exaggerated for effective explanation of the technical content. Accordingly, the shapes of the illustrations may be modified due to manufacturing techniques and / or tolerances. Accordingly, the embodiments of the present invention are not limited to the specific shapes depicted, but also include variations in shape resulting from the manufacturing process.

[0060] FIG. 1 shows an example of a flat-panel 3D image display device and an image device (100) using a depth-of-focus extension contact lens according to the concept of the present invention.

[0061] Referring to FIG. 1, the imaging device (100) of the present invention is largely composed of two parts: a flat-panel 3D image display device that provides a 3D image, and a contact lens that is mounted on a user's eye to expand the depth of focus of the 3D image. The flat-panel 3D image display device is composed of a display device (10), a polarizer (20), and a parallax barrier (30). The display device (10) is a device that provides image information by being composed of a plurality of pixels, and a liquid crystal display (LCD) or an organic light emitting display (OLED) can be used. The display device (10) is composed of first pixels (14) that alternately provide left-eye image information and second pixels (12) that alternately provide right-eye image information.

[0062] A polarizing plate (20) may be provided adjacent to the image display element (10). The polarizing plate (20) may polarize image information from the display element in one polarization direction. As an example, FIG. 1 illustrates a case where a linear polarizing film is applied so that light polarized in the same direction as the ground reaches the user's eyes.

[0063] A parallax barrier (30) is provided adjacent to the polarizing plate (20) to spatially separate the viewpoint images so that the image information of the first pixels (14) and second pixels (12) of the image display element (10) can be provided to the left eye (84) and right eye (82) of the user, respectively. In Fig. 1, a parallax barrier (30) is used as an example of this, but this can be replaced with a lenticular lens.

[0064] The specific shape of the contact lens, which is the second part of the present invention and is mounted on the retina of the user's eye to implement the expansion of the depth of focus of the virtual image, will be expressed in FIG. 2 described below, but FIG. 1 is a conceptual diagram of the contact lens to explain the operating principle of the present invention. The contact lens is configured identically for the user's left and right eyes, and each is divided into a first region in the central portion of the contact lens and a second region elsewhere. The second region of the contact lens is made of a material that transmits polarized light orthogonal to the polarization direction of the polarizing plate (20) of the flat-panel 3D image display device. On the other hand, the first region of the contact lens is made of a material that transmits polarized light having the same polarization direction as the polarizing plate (20) of the flat-panel 3D image display device, or is made of a non-polarizing material.

[0065] When the light (16) of the left-eye image and the light (18) of the right-eye image generated in the above-described flat-panel 3D image display device reach the contact lens (40) mounted on the user's eye, the second region of the contact lens transmits only the light perpendicular to the polarization direction of the left-eye image and the right-eye image, so that the image information does not reach the pupil of the user's eye, and the first region of the contact lens is made of a material that is the same as the polarization direction of the left-eye image and the right-eye image or is non-polarized, so that virtual image information is provided to the user's eye only through this region. At this time, the size of the first region of the contact lens is set to be 2 mm or less, which is smaller than the pupil size of 3 to 8 mm in a normal environment.

[0066] By this, the virtual image generated from the flat-panel 3D image display device is transmitted to only a part of the normal pupil of the user's eye through the first area of ​​the contact lens, so that even without additionally providing a depth-of-focus expansion optical system as described in Reference 4, a virtual image with an expanded depth of focus is provided to the user's eye, so that even when viewing a 3D image with a wide depth of focus, eye fatigue is reduced. In addition, the second area of ​​the contact lens is composed of a material that transmits light orthogonal to the polarization direction of the virtual image, so that the virtual image information generated from the flat-panel 3D image display device is blocked, but 50% of the non-polarized external light around the image display device is transmitted. As a result, the virtual image is provided to only an area of ​​2 mm or less of the user's eye pupil through the first area of ​​the contact lens, thereby providing a virtual image with an expanded depth of focus, and at the same time, external light enters through the second area of ​​the contact lens, so that the user can comfortably view the virtual image in a bright environment. An example according to the embodiment of the present invention of Fig. 1 is a case where a polarizing plate (20) of a flat-panel 3D image display device and a second region of a depth-of-focus expanding contact lens use a linearly polarizing material that transmits linearly polarized light that is orthogonal to each other. Although not shown, the polarizing plate (20) of the flat-panel 3D image display device and the polarizing material of the second region of the depth-of-focus expanding contact lens may use a circularly polarizing material that is orthogonal to each other, and the first region of the contact lens may use a non-polarizing material or a circularly polarizing material having the same polarization direction as the polarizing plate (20) of the flat-panel 3D image display device.

[0067] FIGS. 2a, 2b, 3a, and 3b show specific examples of the contact lens (40) of FIG. 1 according to an embodiment of the present invention.

[0068] Referring to FIGS. 2A and 2B, the user's eye is composed of a lens (74), an iris (76), a pupil (78), and a cornea (79). The size of the pupil varies depending on the illumination of the external environment, but typically has a diameter of 2 to 8 mm. The depth-of-focus expansion contact lens (40) of the present invention can be mounted to cover the cornea (79) of the user's eye, like a general vision-correcting contact lens. That is, the contact lens (40) can be wider than the cornea (79).

[0069] Referring to FIGS. 2a, 2b, 3a and 3b, the depth of focus extended contact lens (40) is composed of a first region (43) located at the center of the lens and a second region (41) located elsewhere.

[0070] The first region (43) of the contact lens is located at the center of the lens and has a diameter smaller than 2 mm, which is the lower limit of the user's normal pupil size, so that it is within the pupil (78) region of the user wearing the contact lens. The second region (41) of the contact lens is formed of a region other than the first region (43) and is formed of a material that transmits polarized light orthogonal to the polarization direction of an image display device that provides a virtual image. As a result, the virtual image generated by the image display device is formed on the retina (72) through the user's pupil via the first region of the contact lens, thereby allowing the user to view a virtual image with an expanded depth of focus regardless of the user's pupil size. In addition, the second region of the contact lens is composed of a material that transmits polarized light (linear polarization or circular polarization) orthogonal to the polarization direction of the image display device that provides the virtual image, so that the virtual image cannot pass through the user's pupil through the second region of the contact lens and be formed on the retina. However, since external light in a general environment provides unpolarized light, it can pass through the user's pupil through the second region of the contact lens and be formed on the retina. Accordingly, a user wearing the contact lens according to the present invention can view a virtual image with an expanded depth of focus while not being dark when observing the external environment or an actual object. Ideally, the second region of the contact lens can view unpolarized external environment light at about half the brightness. At this time, it should be noted that external light can also enter the user's pupil through the first region of the contact lens.

[0071] FIG. 4 shows an example of a contact lens (40) of FIG. 3a, a depth of focus extension contact lens made of a polarizing material.

[0072] Referring to Fig. 4, the contact lens (40) is composed of a first region (43) located at the center and a second region (41) located elsewhere. At this time, the second region (41) is composed of a first linear polarizing material (45a) that transmits polarization orthogonal to the polarization direction of the virtual image, and the first region (43) is composed of a second linear polarizing material (47) that transmits polarization identical to the polarization direction of the virtual image. For example, the first linear polarizing material (45a) may include a horizontal polarizer, and the second linear polarizing material (47) may include a vertical polarizer.

[0073] Although not illustrated, the first region (43) of the contact lens may be composed of a non-polarizing transmissive material. This is because, even if the first region is composed of a non-polarizing material, the virtual image can be transmitted to the user's pupil through the first region, as the image information of the virtual image is blocked by the second region of the contact lens.

[0074] FIG. 5 shows an example of a contact lens (40) of FIG. 3a, a depth of focus extension contact lens made of a circularly polarizing material.

[0075] Referring to FIG. 5, the contact lens (40) is composed of a first region (43) located at the center and a second region (41) located elsewhere. As an example, if the polarization of the virtual image is right-hand circular polarization, the second region (41) is composed of a left-hand circular polarizing material (45b) that transmits polarization orthogonal to the polarization direction of the virtual image, and the first region (43) is composed of a right-hand circular polarizing material (47b) that transmits polarization identical to the polarization direction of the virtual image. At this time, the left-hand circular polarizing material (45b) and the right-hand circular polarizing material (47b) are composed of a linear polarizing plate and a quarter-wave retardation film having an optical axis inclined at 45 degrees, and depending on whether the inclination direction of the quarter-wave retardation film attached to the linear polarizing plate is a positive or negative angle, the left-hand circular polarizing material (45b) or the right-hand circular polarizing material (47b) can be used. For example, the left-handed circularly polarizing material (45b) may include a left-handed circularly polarizing element, and the right-handed circularly polarizing material (47b) may include a right-handed circularly polarizing element.

[0076] Although not shown, the first region (43) of the contact lens may be composed of a non-polarizing transmissive material. This is because, even if the first region is composed of a non-polarizing transmissive material, the virtual image can be transmitted to the user's pupil through the first region, as the image information of the virtual image is blocked by the second region of the contact lens.

[0077] FIG. 6a and FIG. 6b show an example in which a polarization direction indicator is additionally configured for the convenience of the user of the contact lens (40) of FIG. 3a.

[0078] Referring to FIGS. 6A and 6B, the contact lens (40) may further include polarization direction indicators (46). In the second region (41) of the depth-of-focus expanded contact lens (40) according to the present invention, polarization orthogonal to the polarization direction of the virtual image illustrated in FIG. 1 should be blocked, and the virtual image information should be transmitted to the user's pupil only through the first region (43) located at the center of the contact lens. In order to properly implement this, the user must properly wear the contact lens by aligning it to the eye so that the polarization direction of the second region of the contact lens (40) is orthogonal to the polarization direction of the virtual image provided by the image display device that provides the three-dimensional image. In the embodiment of the present invention, when the user mounts the depth-of-focus expanded contact lens (40) on the eye, polarization direction indicators (46) may be additionally configured on both sides of the contact lens in the horizontal direction so that the contact lens can be mounted in accordance with the horizontal direction of the eye. The examples of Figs. 6a and 6b illustrate a case where the second region (41) of the contact lens (40) is arranged to transmit horizontally polarized light when the polarization of the virtual image is vertically polarized light. In this case, when the user wears the contact lens (40) based on the polarization direction indicators (46), the virtual image generated in the 3D image display device is transmitted to the user's pupil only through the first region (43) of the contact lens (40), allowing the user to view a virtual image with a wide depth of focus. As described in the previous embodiment, the first region (43) of the contact lens is composed of a non-polarizing material or a material that transmits polarized light orthogonal to the polarization direction (45a) of the second region (41) of the contact lens. In addition, the polarization indicators (46) of the contact lens can be arranged horizontally on the left and right sides of the outer periphery of the second area of ​​the contact lens for easy viewing by the user when wearing the contact lens, and the shape can include a square block or groove, and can be displayed in a color different from other parts of the contact lens.Although the embodiments of FIGS. 6a and 6b are examples of cases where the polarization of the virtual image information is linearly polarized, the present invention can also be applied to cases where the polarization of the virtual image information is circularly polarized. For example, in cases where the polarization of the virtual image information is left-handed circularly polarized, the second region (41) of the contact lens is composed of a right-handed circularly polarizing material, so that the second region cannot pass through, and the virtual image is formed on the retina of the user's eye pupil only through the first region of the contact lens, so that a virtual image with an expanded depth of focus can be provided to the user.

[0079] FIG. 7a shows an example of configuring a flat-panel 3D image display device by additionally including a polarization direction rotation element (22) adjacent to the image display element (10) composed of the image display panel and polarizing plate of FIG. 1 according to another embodiment of the present invention. Although not illustrated, the flat-panel 3D image display device is configured such that a parallax barrier (30) or a lenticule lens of FIG. 1 is arranged adjacent to the polarization direction rotation element (22) to separately provide left-eye and right-eye images to both eyes of the user, and the user wears a depth-of-focus extension contact lens (40). FIG. 7b shows the polarization direction of a virtual image varied by the image display element (10) and the polarization direction rotation element (22) of FIG. 7a.

[0080] Referring to FIGS. 7a and 7b, the image display element (10) and the polarization rotating device (22) may be configured as a liquid crystal display element capable of changing the transmittance or polarization direction according to an electrical signal.

[0081] For example, an image display element (10) composed of a liquid crystal display element may be composed of a backlight (11), a lower polarizing plate (13), a liquid crystal display element (15) composed of a plurality of pixels, and an upper polarizing plate (17). When virtual image information of the left and right eyes is input to the liquid crystal display element composed of a plurality of pixels arranged between the upper and lower polarizing plates (13, 17) using white light provided from the backlight (11), the virtual image information of the left and right eyes polarized in the polarization direction of the upper polarizing plate (17) is transmitted to the polarization direction rotation element in the image display element (10). The polarization direction rotation element may be composed of, for example, a variable phase difference layer (23) between a first substrate (21) and a second substrate (25). The variable phase difference layer can be composed of a liquid crystal layer in which positive liquid crystals are arranged in parallel and are horizontally aligned, and when an electrical signal is applied to the first substrate and the second substrate, the liquid crystal layer is aligned from the horizontal direction of the substrate to the vertical direction according to the electric field signal intensity, and as the phase difference value of the liquid crystal layer changes, the polarization direction of the image information of the left and right eyes passing through the polarization direction rotation element (22) changes.

[0082] Referring to FIGS. 7a and 7b, when the polarization direction of the upper polarizing plate (17) of the image display element (10) is in the y-axis direction, light having virtual image information generated in the image display element (10) becomes y-axis polarized light (61), and when the y-axis polarized light (61) of the image display element (10) is arranged to have a first angle (φ) in the xy plane with the optical axis direction of the phase difference layer (23) of the polarization direction rotation element (22), a phase difference occurs between the optical axis of the phase difference layer and the axis perpendicular thereto, and the light passing through the phase difference layer is changed into polarized light (62) whose polarization axis of the incident polarized light (61) is rotated by a second angle (θ). At this time, the rotation angle (θ) between the incident polarized light (61) and the polarized light (62) whose polarization axis is rotated after passing through the polarization direction rotation element (22) is determined depending on the change in the phase difference value of the phase difference layer (23) according to the voltage applied to the polarization direction rotation element (22). In general, it is preferable that the first angle (φ) between the polarization direction (61) of the light generated in the image display element (10) and the optical axis direction of the phase difference layer (23) of the polarization direction rotation element (22) be arranged at 45 degrees. The image display element (10) of Fig. 7a is an embodiment using a liquid crystal display element (15), and the image device of the present invention may be an organic light emitting display device (OLED) that does not require a backlight, in which case the image device may be configured as the image display element (10) with the organic light emitting display device and a polarizing plate arranged adjacent thereto.

[0083] FIG. 8a and FIG. 8b show an example of a method for optimizing the polarization direction of a virtual image generated by the image display element (10) and polarization direction rotation element (22) of FIG. 7a according to the condition of the contact lens (40) worn by the user.

[0084] In the case of Fig. 8a, as in the case exemplified in Fig. 1, the polarization direction of the virtual image generated from the flat panel display device is orthogonal to the polarization direction (45a) of the second region (41) of the contact lens (40) worn by the user, so that the information of the virtual image is transmitted to the pupil through the first region (43) located at the center of the contact lens to form an image on the retina, thereby providing the user with a virtual image with an ideal expanded depth of focus. In the case of Fig. 8a, this corresponds to the case where the user wears the contact lens (40) on the eye with the horizontal of the polarization direction indicator ideally aligned. In this case, the phase difference can be adjusted by applying a voltage to the upper and lower electrodes of the polarization change element so that the polarization (y-axis polarization, 61) generated from the image display element (10) of Fig. 7a is maintained even after passing through the polarization direction rotation element (22) so that the phase difference becomes 0 or n*2π (radian). At this time, n is an integer. On the other hand, as shown in FIG. 8b, when the user wears the contact lens (40) on the eye at a certain angle (θ) from the horizontal direction, when the polarization (y-axis polarization, 61) of the virtual image generated from the image display element (10) of FIG. 7a is transmitted to the contact lens (40) worn by the user, some of the light of the virtual image passes through the second region (41) in addition to the first region (43) located at the center of the contact lens and reaches the user's pupil, thereby lowering the characteristic of providing a virtual image with an expanded depth of focus regardless of the pupil size, which is the purpose of the present invention. To improve this, the phase difference can be adjusted by applying voltage to the upper and lower electrodes of the polarization direction rotation element (22) to generate a virtual image polarization (y-axis polarization, 61) orthogonal to the polarization direction (45c) of the second area (41) of the contact lens worn by the user, and a virtual image polarization (polarization tilted at a certain angle (θ) from the y-axis, 62) generated from the image display element (10) of FIG. 7a.As a result, even if the user does not mount the contact lens (40) in an ideally aligned horizontal direction, the user can observe a virtual image with an ideal expanded depth of focus by controlling the electrical signal of the polarization direction rotation element (22) additionally provided to the image display element.

[0085] FIGS. 8A and 8B illustrate an example of the present invention, which comprises a virtual image of linearly polarized light generated from an image display device and a corresponding linearly polarized material in a second region of a contact lens worn by a user, which is orthogonal to the linearly polarized light. The implementation of the present invention is equally applicable to cases where circularly polarized light is used as well as linearly polarized light. In this case, the upper polarizing plate of the image display device is composed of a circularly polarizing plate, and the second region of the contact lens (40) worn by the user is composed of a circularly polarized material orthogonal to the polarization direction of the virtual image generated from the image display device. Although not shown, circular polarization is a polarization state in which left-hand circular polarization and right-hand circular polarization are orthogonal to each other, and the material that implements this is composed of a combination of a linear polarization film and a quarter wave film, so that ideally, even if the horizontal direction of the lens mounted on the eye is slightly misaligned, the light of the first polarization (left-hand circular polarization) of the virtual image generated by the image display device is maintained in an orthogonal state to the polarization (right-hand circular polarization) of the second region of the contact lens, so that the virtual image is transmitted to the pupil only through the first region (43) of the contact lens, and there is no problem in expanding the depth of focus. However, in practice, since the compensation film that constitutes the circular polarization material is wavelength-dependent, a polarization direction rotation element (22) arranged in front of the image display element may be required even when circular polarization is used.

[0086] Fig. 9 shows an example of an imaging device (100) using a near-eye optical element and a depth-of-focus extension contact lens (40) according to the concept of the present invention.

[0087] Referring to FIG. 9, the imaging device of the present invention can be largely divided into two parts. The first part is a near-eye optical element, and the second part is a depth-of-focus extension contact lens (40). The second part, the contact lens (40), has the same configuration and function as the contact lens described in FIGS. 2A to 6B. The first part, the near-eye optical element, has various types, but FIG. 9 shows a birdbath type near-eye optical element as an example to explain the concept of the present invention. A typical birdbath type near-eye optical element is composed of an image display element (10), a beam splitter (24), and a semi-transmissive concave mirror (26). The virtual information generated in the image display element (10) sends light in the first linear polarization direction to the beam splitter (24), and the light reflected from the beam splitter is reflected by the semi-transparent concave mirror (26), passes through the beam splitter, and is transmitted to the depth of focus expansion contact lens (40) mounted on the user's eye. At this time, the light of the virtual image information transmitted to the contact lens is provided to the contact lens in an area wider than the typical average pupil size of 2 to 8 mm, and the polarization direction is maintained in the first linear polarization direction. The first area (43) of the contact lens (40) mounted on the used eye is located at the center of the contact lens and has a diameter size of 2 mm or less, which is smaller than the typical user pupil size. This area is configured as a non-polarized light transmission area or a first linear polarized light transmission area. The second region (41) of the contact lens (40) is a region through which light of a second linear polarization direction orthogonal to the first linear polarization direction of the virtual image is transmitted. As a result, the virtual image of the near-eye optical element is polarized with the first linear polarization and enters the contact lens worn by the user, thereby providing virtual image information to the user's pupil only through the first region (43) of the contact lens, thereby forming an image on the retina, thereby providing the user with a virtual image with an expanded depth of focus regardless of the user's pupil size.Meanwhile, unpolarized light of an external object (28) is incident on a contact lens worn by a user through a semi-transparent concave mirror (26) and a beam splitter (24), and the second linearly polarized light forms an image on the retina through the pupil through the second region (41) of the contact lens, or the first linearly polarized light forms an image on the retina through the pupil through the first region (43) of the contact lens (if the first region is a first linearly polarized light transmission region), or the unpolarized light forms an image on the retina through the pupil (if the first region is a non-polarized light transmission region), so that the user can see a virtual image with an expanded depth of focus while brightly viewing the external object and the external foreground.

[0088] A depth-of-focus extended contact lens used with a near-eye optical element may also be arranged so that the polarization direction of the second region (41) of the contact lens is inclined at a predetermined angle (θ) from the horizontal direction when the user wears it on the eye, as shown in FIG. 8b. In this case, a polarization direction rotation element (22) capable of rotating the polarization direction of virtual information generated in the image display element (10) by a predetermined angle (θ) according to an electrical signal may be additionally arranged. The principle and effect thereof are the same as those in the drawings and detailed descriptions of FIGS. 8a and 8b.

[0089] Fig. 10 shows an example of an imaging device (100) that applies a glasses-type 3D image display device and a depth-of-focus extension contact lens according to the concept of the present invention.

[0090] Referring to FIG. 10, a glasses-type 3D image display device is composed of an image display element (10) in which binocular parallax images are alternately arranged on a plurality of pixels and a patterned polarizing film (20) arranged adjacent to the image display element (10). The patterned polarizing film (20) has a first linear polarizing transparent film and a second linear polarizing transparent film arranged in the same manner as the arrangement of the binocular parallax images of the image display element (10). For example, in FIG. 10, a first linear polarizing transparent film is arranged adjacent to pixels in which left-eye images are arranged, and a second linear polarizing transparent film is arranged adjacent to pixels in which right-eye images are arranged. A depth-of-focus expanding contact lens (40) applied to a glasses-type 3D image display device is composed of a first region located at the center, having a diameter of 2 mm or less, and including a linear polarizing material, and a second region located in the other regions and made of an opaque material. In addition, the first area of ​​the contact lens is distinguished into a left-eye contact lens (44) made of a first linearly polarized light-transmitting film and a right-eye contact lens (42) made of a second linearly polarized light-transmitting film. The contact lens shown in Fig. 10 is shown as being positioned apart from the pupil and having a flat shape for easy explanation of the concept of the present invention, but is of a type that can be worn on the cornea of ​​the eye, as shown in Fig. 9.

[0091] As shown in Fig. 10, a glasses-type 3D image display device provides a left-eye image (first linear polarization) and a right-eye image (second linear polarization) to both eyes at the user's eye position. In order to view the left-eye and right-eye images separately, the user must typically wear polarized glasses that are orthogonal to each other on both eyes to view the 3D image. In the present invention, in order to view a wide depth of focus of a glasses-type 3D image, a left-eye image polarized with a first linear polarization is incident on the pupil through a first region of a left-eye contact lens (44) to form an image on the retina, and an opaque material is included in the second region, which is the other region, to block external light, and a right-eye image polarized with a second linear polarization is incident on the pupil through a first region of a right-eye contact lens (42) to form an image on the retina, and an opaque material is included in the second region, which is the other region, to block external light. The present invention can reduce eye fatigue due to focus adjustment and convergence mismatch (VAC) even when observing a 3D image with a wider depth of focus than when observing a 3D image by wearing conventional polarizing glasses. FIG. 10 shows an example of the present invention using linear polarization, but when a patterned circular polarization film is used instead of a patterned linear polarization film (11a) arranged in front of an image display element (10), and the first areas of the left and right eye contact lenses (44, 42) worn by the user are made of circular polarization films that are orthogonal to each other, the user can still view a 3D image with an expanded depth of focus, which is an effect of the present invention. And Fig. 10 shows an example of transmitting images of the left and right eyes to the user's left and right eye contact lenses in a spatial division manner so that the user can view a 3D image. However, although not shown, if a polarizing element that transmits the first linearly polarized light and the second linearly polarized light in a time division manner in synchronization with an image display element (10) that provides left and right eye images in a time division manner is used together with the contact lens (40) of Fig. 10, a time-division 3D image can be provided to the user.

[0092] Fig. 11 shows an example of an imaging device (100) that applies a flat-panel 3D image display device and a depth-of-field extension contact lens according to the concept of the present invention. Figs. 12a to 14b show an example of the depth-of-field extension contact lens (40) of Fig. 11. Figs. 15a to 15b show an example of a method in which the imaging device (100) of Fig. 11 provides two ultra-multi-viewpoint images to each of the user's eyes in a time-division manner.

[0093] Referring to FIG. 11, the imaging device (100) of the present invention is largely composed of two parts: a flat-panel 3D image display device that provides time-segmented 3D images, and a contact lens that is mounted on a user's eye to expand the depth of focus of the time-segmented 3D images. The flat-panel 3D image display device is composed of a display device (10), a variable polarizer (20a), and a parallax barrier (30). The display device (10) is a device that provides image information by being composed of a plurality of pixels, and a liquid crystal display (LCD) or an organic light emitting display (OLED) can be used. The display device (10) is composed of first pixels (14) that alternately provide left-eye image information and second pixels (12) that alternately provide right-eye image information.

[0094] A variable polarizing plate (20a) may be provided adjacent to an image display element (10). The variable polarizing plate (20a) is an element that transmits only linearly polarized light that is orthogonal to each other, alternating within one frame, the image information output from the image display element. For example, in FIG. 11, the variable polarizing plate (20a) sequentially and time-divisionally alternates between a first linearly polarized light having the same polarization direction as the ground and a second linearly polarized light orthogonal thereto. The variable polarizing plate (20a) that performs this operation may be implemented as a liquid crystal display (LCD) that can change the polarization direction according to an electrical signal.

[0095] A parallax barrier (30) is provided adjacent to the polarizing plate (20) to spatially separate the viewpoint images so that the image information of the first pixels (14) and second pixels (12) of the image display element (10) can be provided to the left eye (84) and right eye (82) of the user, respectively. In Fig. 11, a parallax barrier (30) is used as an example of this, but this can be replaced with a lenticular lens.

[0096] The specific shape of the contact lens that is mounted on the retina of the user's eye to expand the depth of focus of a virtual image, which is the second part of the present invention, will be expressed in FIGS. 12a to 14b, which will be described later. However, FIG. 11 will be described as a conceptual diagram of a contact lens to explain the operating principle of the present invention. The contact lens (40) is configured identically for the user's left and right eyes, and is divided into a first region a at the center of the contact lens, a first region b, and a second region elsewhere. The first region a and the first region b of the contact lens are arranged adjacent to the center of the contact lens and are composed of materials that transmit polarization directions orthogonal to each other. For example, as shown in FIG. 11, when the first region a of the contact lens is composed of a first linearly polarized light-transmitting material, the first region b is composed of a second linearly polarized light-transmitting material. The second region of the contact lens is composed of an opaque material that blocks all light.

[0097] When the light (16) of the left-eye image and the light (18) of the right-eye image generated in the above-described flat-panel 3D image display device reach the contact lens (40) mounted on the user's eye, the second area of ​​the contact lens is made of an opaque material to block all light reaching the contact lens. In addition, the virtual image light (16) of the left eye and the virtual image light (18) of the right eye are transmitted to the user's contact lens (40) as first linearly polarized light and second linearly polarized light alternately within one frame by the image display element (10) and the variable polarizing plate (20a). The first linearly polarized light passes through the first area of ​​the contact lens, passes through the first position of the user's eye pupil, and forms an image on the retina, and the second linearly polarized light passes through the first area of ​​the contact lens, passes through the second position of the user's eye pupil, and forms an image on the retina. At this time, the sizes of the first and second a areas of the contact lens are set to a size of 2 mm or less, which is smaller than the pupil size of 3 to 8 mm in a normal environment.

[0098] By this, the virtual images of the first linear polarization and the second linear polarization generated in a time-division manner in a flat-panel 3D image display device are transmitted to only a part of the normal pupil of the user's eye through the first a and the first b areas of the contact lens, respectively, so that even without additionally providing a depth-of-focus expansion optical system as described in Reference 4, a virtual image with an expanded depth of focus is provided to the user's eye, so that even when viewing a 3D image with a wide depth of focus, eye fatigue is reduced. In addition, the virtual images provided to the first a and the first b areas of the contact lens become adjacent viewpoint images provided in a time-division manner, so that two viewpoint images are provided to the eye pupil, and thus a super-multi-viewpoint image that can implement an effect similar to a hologram can be shown to the user. As a result, two virtual images of 2 mm or less in size can be provided to the pupil of the user's eye through the first a and the first b areas of the contact lens, so that a super-multi-viewpoint virtual image with an expanded depth of focus similar to a hologram can be provided. An example according to the embodiment of the present invention of Fig. 11 is a case where a variable polarizing plate (20a) that transmits first linearly polarized light and second linearly polarized light in a time-division manner of a flat-panel 3D image display device and a linearly polarizing material that transmits first linearly polarized light and second linearly polarized light that are orthogonal to each other in the first a region and the first b region of a depth-of-focus expanding contact lens are used. Although not shown, a variable polarizing element (20) that transmits first circularly polarized light and second circularly polarized light in a time-division manner of a flat-panel 3D image display device and a circularly polarizing material that transmits first circularly polarized light and second circularly polarized light that are orthogonal to each other in the first a region and the first b region of a depth-of-focus expanding contact lens may be used.

[0099] FIGS. 12a and 12b show an example of a depth-of-focus extension contact lens, one of the imaging device components of FIG. 11, mounted on the retina of a user's eye in the XY plane and the XZ plane.

[0100] FIG. 13a and FIG. 13b show an example of the shape of a depth-of-focus extension contact lens, which is one of the imaging device components of FIG. 11, in the XY plane and the XZ plane.

[0101] Referring to FIGS. 12A and 12B, the user's eye is composed of a lens (74), an iris (76), a pupil (78), and a cornea (79). The size of the pupil varies depending on the illumination of the external environment, but typically has a diameter of between 2 and 8 mm. The depth-of-focus expansion contact lens (40) of the present invention can be mounted to cover the cornea (79) of the user's eye, like a general vision-correcting contact lens. That is, the contact lens (40) can be wider than the cornea (79).

[0102] Referring to FIGS. 12a, 12b, 13a and 13b, the depth of focus extended contact lens (40) is composed of a first area (43a) located at the center of the lens, a first area (43b) located at the center of the lens, and a second area (41) located elsewhere.

[0103] The first a region (43a) and the first b region (43b) of the contact lens are located at the center of the lens and have a diameter smaller than 2 mm, which is the lower limit of the user's normal pupil size, so that they are positioned within the pupil (78) region of the user wearing the contact lens or include a part of the pupil region. The first a region (43a) of the contact lens is made of a first linearly polarized light transmitting material and the first b region (43b) is made of a second linearly polarized light transmitting material, so that when the image display device provides parallax images of the first linearly polarized light and the second linearly polarized light in a time-division manner within one frame, the parallax image adjacent to the pupil of the user's eye is transmitted through the first a region and the first b region of the contact lens, so that two super-multiple viewpoints with a wide depth of focus are provided to the left and right eyes, respectively, so that the user can view a virtual image similar to a hologram. The second region (41) of the contact lens is composed of a region other than the first region (43a) and the first region (43b), and is made of an opaque material to block all light generated from the image display device. Although not illustrated in the embodiment of the present invention, the polarization directions of the first linear polarization and the second linear polarization indicated in FIGS. 11 to 13b may be changed into two sets of linear polarizations that are orthogonal to each other in different polarization directions. In addition, although the embodiment illustrates and describes only the case where the first linear polarization and the second linear polarization are orthogonal to each other, the first circular polarization and the second circular polarization (left-handed circular polarization and right-handed circular polarization) that are orthogonal to each other may be used by applying the concept of the present invention.

[0104] Figures 14a and 14b show an example in which a polarization direction indicator (46) is additionally configured for the convenience of the user of the contact lens (40) of Figure 13a.

[0105] Referring to FIGS. 14a and 14b, the contact lens (40) may further include polarization direction indicators (46). Since the second region (41) of the depth-of-focus extended contact lens (40) according to the present invention is made of an opaque material, there is no problem even if the horizontal alignment is misaligned when the user wears the contact lens on the eye. However, if the first and second linear polarization directions of the variable polarizing element (20a) of FIG. 11 and the polarization directions of the first a and first b regions of the contact lens (40) worn by the user are not the same as or orthogonal to each other, the first parallax image provided to the first a region of the contact lens (40) in time division and the second parallax image provided to the first b region are partially mixed, thereby degrading the image quality of the super multi-viewpoint image. To improve this problem, an embodiment of the present invention may additionally configure polarization direction indicators (46) on both sides of the horizontal direction of the contact lens so that the contact lens can be mounted in alignment with the horizontal direction of the eye when the user mounts the depth of focus extension contact lens (40) on the eye. The examples of FIGS. 14a and 14b are cases where the first linear polarization of the virtual image provided in a time-division manner is arranged to be identical to the linear polarization direction of the 1a region of the contact lens, and the second linear polarization of the virtual image is arranged to be identical to the linear polarization direction of the 1b region of the contact lens. In this case, when the user wears the contact lens (40) based on the polarization direction indicators (46), the virtual image of the first linear polarization generated in the 3D image display device is transmitted to the user's pupil only through the 1a region (43a) of the contact lens (40), and the virtual image of the second linear polarization is transmitted to the user's pupil only through the 1b region (43b) of the contact lens, so that the user can view a super-multi-viewpoint virtual image with a wide depth of focus. The polarization indicators (46) of the contact lens can be arranged on the left and right sides of the outer periphery of the second region of the contact lens in a horizontal direction for easy viewing by the user when wearing it, The shape may include square blocks or grooves, and may be colored differently from the rest of the contact lens.Although the embodiments of FIGS. 14a and 14b are examples of cases where the polarization of the virtual image information is linearly polarized, they can also be applied to cases where the polarization of the virtual image information is circularly polarized. For example, when virtual image information of the first circularly polarized light and the second circularly polarized light (left-circularly polarized light and right-circularly polarized light) are sequentially transmitted in a time-division manner from a variable polarizing element (20a) to a contact lens worn by a user, the 1a region of the contact lens is composed of a first circularly polarized light (left-circularly polarized light) transmitting material and transmits only the virtual information of the first circularly polarized light (left-circularly polarized light) to the pupil, and the 1b region of the contact lens is composed of a second circularly polarized light (right-circularly polarized light) transmitting material and transmits only the virtual information of the second circularly polarized light (right-circularly polarized light) to the pupil.

[0106] FIGS. 15A and 15B illustrate an embodiment of the present invention in which a variable polarizing element (20a) disposed in front of an image display element (10) shown in FIG. 11 divides one frame into two, and each of the two orthogonal linearly polarized lights transmits an image that passes through a contact lens and enters the eye pupil, frame by frame. A method of providing a first parallax image and a second parallax image to a user's eye through a contact lens by time-dividing one frame into two frames is conceptually illustrated in FIGS. 15A and 15B according to each split frame situation. The drawing of FIG. 11 is a diagrammatic representation of such a situation.

[0107] Referring to FIG. 15a, in a 1 / 2 frame, the image display element (10) provides first parallax images of the left and right eyes, and the variable polarizing element (20a) transmits polarized light in the first linear polarization direction according to an electrical signal. Thereafter, the left and right eye images are spatially separated through an adjacent parallax barrier (30) to provide the first linearly polarized left-eye image (16) and right-eye image (18) to the left and right eye positions of the user, respectively. The left-eye image and the right-eye image that reach the left and right eye positions of the user pass through the 1a region (the first linearly polarized light transmitting region (43a)) of the contact lenses (44, 42) of the left and right eyes, respectively, and pass through the pupil to form an image on the retina. Thus, the imaging device (100) of the present invention can provide the first parallax images of the left and right eyes to the user during a 1 / 2 frame.

[0108] Referring to FIG. 15b, in a 2 / 2 frame, the image display element (10) provides second parallax images for the left and right eyes, and the variable polarizing element (20a) transmits polarized light in the second linear polarization direction according to an electrical signal. Thereafter, the left and right eye images are spatially separated through an adjacent parallax barrier (30) to provide second linearly polarized left-eye images (16) and right-eye images (18) to the left and right eye positions of the user, respectively. The left-eye images and right-eye images that reach the left and right eye positions of the user pass through the 1b region (second linearly polarized light transmitting region (43b)) of the contact lenses (44, 42) of the left and right eyes, respectively, and pass through the pupils to form images on the retina. Thus, the imaging device (100) of the present invention can provide second parallax images for the left and right eyes to the user during a 2 / 2 frame. At this time, it should be noted that the first and second linear polarizations have the characteristic of being orthogonal to each other, and the linear polarization direction can be changed by a certain angle from the direction shown in the example of the present invention. In addition, although the present invention was described using a linear light source as an example, it can also be implemented using circular polarization.

[0109] Fig. 16 shows an example of an imaging device (100) that implements a multi-viewpoint space division method according to the concept of the present invention.

[0110] The contact lens (40) worn by the user of Fig. 16 is identical to that illustrated in Fig. 11, and its specific shape and function are identical to those illustrated in Figs. 12a to 14b and the descriptions thereof in the specification. Therefore, the following description focuses on the configuration of the three-dimensional image display device of Fig. 16.

[0111] Referring to FIG. 16, the image display element (10) is composed of a plurality of pixels, and pixels (12) on which a first parallax image is arranged and pixels (14) on which a second parallax image is arranged are arranged adjacently and alternately, and the pixels (12) on which the first parallax image is arranged are composed of pixels (12a) on which a left-eye image is arranged and pixels (12b) on which a right-eye image is arranged, and the pixels (14) on which the second parallax image is arranged are composed of pixels (14a) on which a left-eye image is arranged and pixels (14b) on which a right-eye image is arranged. A patterned polarizing plate (20b) is attached to the front of the image display element (10). The patterned polarizing plate (20b) is composed of two regions. The first region is composed of a polarizing material that transmits the first linear polarization direction and is arranged corresponding to the pixels (12) on which the first parallax image is arranged, and the second region is composed of a polarizing material that transmits the second linear polarization direction orthogonal to the first linear polarization direction and is arranged corresponding to the pixels (12) on which the second parallax image is arranged. Thereafter, a left-eye image (16) and a right-eye image (18) having two viewpoint images (the first parallax image and the second parallax image) are provided to the user's eye position through a parallax barrier (30) that spatially separates the left and right eyes. In Fig. 16, a parallax barrier is used as an embodiment of the present invention, but it can be configured by replacing it with a lenticule lens.

[0112] Among the left-eye images (16) that have reached the user's eye position, the first parallax image passes through the first a region of the user's left-eye contact lens (44) and transmits the first linearly polarized image to the pupil, and the second parallax image passes through the first b region of the user's left-eye contact lens (44) and transmits the second linearly polarized image to the pupil, so that two different viewpoint super-multi-viewpoint images with a wide depth of focus are formed on the retina. Meanwhile, among the right-eye images (18) that have reached the user's eye position, the first parallax image passes through the first a region of the user's right-eye contact lens (42) and transmits the first linearly polarized image to the pupil, and the second parallax image passes through the first b region of the user's right-eye contact lens (42) and transmits the second linearly polarized image to the pupil, so that two different viewpoint super-multi-viewpoint images with a wide depth of focus are formed on the retina.

[0113] As a result, the imaging device (100) of the present invention can provide a user with a natural three-dimensional image similar to a hologram by implementing a spatially divided super-multiple-viewpoint using an image display element (10) in which two parallax images are spatially separated into a left-eye image and a right-eye image, a patterned polarizing plate (20b) correspondingly separated into regions transmitting mutually orthogonal polarizations, a parallax separation means (a parallax barrier or a lenticular lens), and a depth-of-focus extension contact lens of FIGS. 13a to 14b.

[0114] FIG. 17a and FIG. 17b show an example of an imaging device (100) that provides two-viewpoint super-multi-viewpoint images in time division by applying a near-eye optical element and a depth-of-focus extension contact lens (40) according to the concept of the present invention.

[0115] Referring to FIGS. 17a and 17b, the imaging device of the present invention can be largely divided into two parts. The first part is a near-eye optical element, and the second part is a depth-of-focus extension contact lens (40). The second part, the contact lens (40), has the same configuration and function as the contact lens described in FIGS. 11 to 15b. The first part, the near-eye optical element, has various types, but FIGS. 17a and 17b show a birdbath type near-eye optical element as an example to explain the concept of the present invention. A typical birdbath type near-eye optical element is composed of an image display element (10), a beam splitter (24), and a semi-transmissive concave mirror (26). The present invention divides one frame into two sub-frames (1 / 2 frame and 2 / 2 frame), and provides a first parallax image of first linear polarization to the eye in the 1 / 2 frame as shown in FIG. 17a, and provides a second parallax image of second linear polarization to the eye in the 2 / 2 frame as shown in FIG. 17b.

[0116] Referring to Fig. 17a, a first parallax image is arranged on an image display element (10) in a 1 / 2 frame, and a polarization direction rotation element (22) that adjusts the polarization direction according to an electrical signal arranged adjacent to and below the image display element (10) is adjusted to transmit the first linearly polarized light. The first parallax image of the first linearly polarized light is sent to a beam splitter (24), and the light reflected from the beam splitter is reflected by a semi-transparent concave mirror (26), passes through the beam splitter, and is transmitted to a depth-of-focus expansion contact lens (40) mounted on the user's eye. At this time, the light of the first parallax image of the first linearly polarized light transmitted to the contact lens passes through a first a region (43a) that transmits the first linearly polarized light arranged in the center of the contact lens (40) and forms an image on the retina through the pupil. The first a region of the contact lens (40) has a diameter of 2 mm or less, which is smaller than the typical user pupil size. The first b region (43b) of the contact lens (40) transmits the second linearly polarized light, and the second region is made of an opaque material, so that the first parallax image of the first linearly polarized light generated by the near-eye optical element is blocked by the first b region and the second region of the contact lens. As a result, the first parallax image of the first linearly polarized light of the near-eye optical element provides virtual image information to the user's pupil only through the first a region (43a) of the contact lens, thereby forming an image on the retina, thereby providing the user with a virtual image with an expanded depth of focus regardless of the user's pupil size.

[0117] Referring to FIG. 17b, a second parallax image is arranged on the image display element (10) in a 2 / 2 frame, and a polarization direction changing element (22) that adjusts the polarization direction according to an electrical signal arranged adjacent to and below the image display element (10) is adjusted to transmit the second linearly polarized light. The second parallax image of the second linearly polarized light is sent to a beam splitter (24), and the light reflected from the beam splitter is reflected by a semi-transparent concave mirror (26), passes through the beam splitter, and is transmitted to a depth-of-focus expanding contact lens (40) mounted on the user's eye. At this time, the light of the second parallax image of the second linearly polarized light transmitted to the contact lens passes through the 1b region (43b) that transmits the second linearly polarized light arranged in the center of the contact lens (40) and forms an image on the retina through the pupil. The first b region of the contact lens (40) has a diameter of 2 mm or less, which is smaller than the typical user pupil size. The first a region (43a) of the contact lens (40) transmits the first linearly polarized light, and the second region is made of an opaque material, so that the second parallax image of the second linearly polarized light generated by the near-eye optical element is blocked by the first a region and the second region of the contact lens. As a result, the second parallax image of the second linearly polarized light of the near-eye optical element provides virtual image information to the user's pupil only through the first b region (43b) of the contact lens, thereby forming an image on the retina, thereby providing the user with a virtual image with an expanded depth of focus regardless of the user's pupil size.

[0118] By providing a two-point multi-viewpoint image to the user's pupil through time division of the above 1 / 2 frame and 2 / 2 frame, the user can observe a three-dimensional image similar to a hologram.

[0119] Fig. 18 shows an example of an imaging device (100) that provides a two-viewpoint super-multi-viewpoint image by spatial division by applying a near-eye optical element and a depth-of-focus extension contact lens (40) according to the concept of the present invention.

[0120] Referring to FIG. 18, the image display device of the present invention is a birdbath type near-eye optical element identical to that of FIGS. 17a and 17b. Therefore, the following description will focus on the differences from the embodiment of the present invention of FIGS. 17a and 17b.

[0121] The image display element (10) has first and second parallax images alternately arranged on a plurality of pixels, and the patterned polarizing plate (21) arranged adjacent to and below the image display element (10) is configured with a polarization region through which first linear polarization light transmits corresponding to the pixels through which the first parallax image is arranged, and a polarization region through which second linear polarization light transmits corresponding to the pixels through which the second parallax image is arranged. The first parallax image generated in the image display element (10) becomes first linear polarization light as it passes through the patterned polarizing plate (21), and is sent to the beam splitter (24), and the light reflected from the beam splitter is reflected from the semi-transmissive concave mirror (26), passes through the beam splitter, and is transmitted to the depth of focus expansion contact lens (40) mounted on the user's eye. The second parallax image generated in the image display element (10) becomes second linearly polarized light as it passes through the pattern polarizing plate (21) and is transmitted to the contact lens (40) through the same path. At this time, the light of the first parallax image of the first linearly polarized light transmitted to the contact lens passes through the first a region (43a) that transmits the first linearly polarized light arranged in the center of the contact lens (40) and forms an image on the retina through the pupil. In addition, the light of the second parallax image of the second linearly polarized light transmitted to the contact lens passes through the first b region (43b) that transmits the second linearly polarized light arranged in the center of the contact lens (40) and forms an image on the retina through the pupil. The light that reaches the second region (41) of the contact lens is blocked. As a result, by providing a two-viewpoint super multi-viewpoint image to the user's pupil, the user can observe a three-dimensional image similar to a hologram.

[0122] The contact lens (40) used as an example of the present invention in Fig. 18 has the shape of Figs. 13a to 14b, and when the user wears the contact lens (40), the horizontal direction may not be accurate. In this case, the first parallax image and the second parallax image may be partially mixed in the first a region (43a) and the first b region (43b) of the contact lens and transmitted to the pupil, which may deteriorate the image quality of the three-dimensional image. To compensate for this, a polarization direction rotation element (22) may be additionally placed adjacent to and below the pattern polarizing plate (21). When the horizontal direction of the contact lens (40) worn by the user is rotated by a certain angle, the polarization direction of the first linear polarization and the second linear polarization passing through the polarization direction rotation element (22) is rotated by a certain angle by controlling the electrical signal, so that the first parallax image and the second parallax image are accurately separated and transmitted to the pupil, thereby providing an optimal 3D image.

[0123] FIGS. 19a and 19b show an example of applying an enula aperture to the contact lens (40) of FIGS. 3a and 3b as another embodiment of the present invention.

[0124] Referring to FIGS. 19A and 19B , the first region (43) of the contact lens (40) may include an annular aperture. The first region (43) may be configured to include a circular opaque region in the center of the region from a planar perspective, such that the transmissive region of the first region (43) may have a ring shape. The annular aperture may reduce diffraction effects compared to a regular aperture of the same size, thereby increasing the depth of focus of a high-resolution image.

[0125] Therefore, the imaging device (100) of the present invention can improve the image quality of a three-dimensional image by increasing the depth of focus using the first region (43) of the enular aperture. The effect of the enular aperture used in the imaging device of the present invention is the same as the effect described in Patent Document 4, which is a prior patent of the present inventor. The enular aperture applied in FIGS. 19a and 19b can also be applied to the contact lens applied as another embodiment of the present invention of FIGS. 5 to 6b and 12a to 14b.

[0126] While the embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering the technical spirit or essential characteristics thereof. Therefore, the embodiments described above should be understood to be illustrative in all respects and not restrictive.

Claims

1. An image display element that generates light to display an image; A polarizing plate positioned adjacent to the image display element to polarize the light, A contact lens having a circular shape that is positioned apart from the polarizing plate and can be worn on the user's cornea, The above contact lens comprises a first region having a diameter of 2 mm or less and disposed in the central portion, and a second region excluding the first region, An imaging device characterized in that the second region is composed of a polarizing material orthogonal to the polarization direction of light displaying an image passing through the polarizing plate.

2. In paragraph 1, An imaging device characterized in that the first region of the contact lens is a non-polarized light transmitting region.

3. In paragraph 1, An imaging device characterized in that the first region of the contact lens is composed of a polarizing material, and the polarization direction of the polarizing material is the same as the polarization direction of light displaying an image passing through the polarizing plate.

4. In paragraph 3, An imaging device characterized in that the above polarization is linear polarization.

5. In paragraph 3, An imaging device characterized in that the above polarization is circular polarization.

6. In paragraph 4 or 5, An imaging device characterized in that the above contact lens additionally includes a polarization direction indicator that indicates the polarization direction.

7. In paragraph 1, An imaging device characterized in that the first region of the contact lens has an annular shape.

8. In paragraph 1, An imaging device characterized in that a polarization direction rotation element is additionally provided adjacent to the polarizing plate.

9. In paragraph 8, An imaging device characterized in that the polarization direction rotation element is adjusted so that the polarization direction of the second area of ​​the contact lens worn on the user's cornea and the polarization direction of light passing through the polarization direction rotation element are orthogonal.

10. In paragraph 1, An imaging device characterized in that a first image (left-eye image) and a second image (right-eye image) are alternately arranged on the image display element, and an optical film is additionally arranged at a predetermined interval on the front surface of the polarizing plate to spatially separate the first image and the second image, so that the first image is transmitted to a contact lens worn on the user's left eye and the second image is transmitted to a contact lens worn on the user's right eye.

11. In paragraph 10, An imaging device characterized in that the above optical film is a parallax barrier or a lenticular lens.

12. In paragraph 1, An imaging device characterized in that a near-eye optical element is additionally arranged adjacent to the polarizing plate to simultaneously view an external object and the image in the contact lens.

13. In paragraph 12, An imaging device characterized in that the above-mentioned near-eye optical element includes a beam splitter and a semi-transparent concave mirror.

14. An image display element that generates light to display an image, A polarizing element arranged adjacent to the image display element to polarize the light, A contact lens having a circular shape that is spaced apart from the polarizing element and can be worn on the user's cornea, The above contact lens includes a first area 1a and a first area 1b with a diameter of 2 mm or less, spaced apart at a certain interval in the central portion, It consists of a second region excluding the first a region and the first b region of the above contact lens, The first a region of the above contact lens is a first polarization transmitting region, the first b region is a second polarization transmitting region, and the first polarization and the second polarization are orthogonal to each other. An imaging device characterized in that the second region of the contact lens is composed of an opaque material.

15. In paragraph 14, An imaging device characterized in that the first polarization and the second polarization of the above contact lens are linear polarizations.

16. In paragraph 14, An imaging device characterized in that the first polarization and the second polarization of the above contact lens are circular polarizations.

17. In paragraph 14, The above image display device provides a first parallax image and a second parallax image by time-dividing one frame, The above polarizing element is synchronized with the time division of the image display element to polarize with the first polarization in the case of the first parallax image and with the second polarization in the case of the second parallax image. An imaging device characterized in that the first parallax image is transmitted to the user's pupil through the first a region of the contact lens, and the second parallax image is transmitted to the user's pupil through the first b region of the contact lens.

18. In paragraph 14, The above image display element is composed of a plurality of pixels, and a first parallax image and a second parallax image are arranged in adjacent pixels, The above polarizing element has first and second polarizing regions arranged alternately, The first polarization area of ​​the polarizing element is arranged corresponding to the pixels on which the first parallax image of the image display element is arranged, and the second polarization area of ​​the polarizing element is arranged corresponding to the pixels on which the second parallax image of the image display element is arranged. An imaging device characterized in that the first parallax image is transmitted to the user's pupil through the first a region of the contact lens, and the second parallax image is transmitted to the user's pupil through the first b region of the contact lens.

19. In paragraph 17 or 18, An imaging device characterized in that a polarization direction rotation element is additionally provided adjacent to the polarizing element.

20. In paragraph 19, An imaging device characterized in that the polarization direction rotation element is adjusted so that the polarization direction of the first a region of the contact lens worn on the user's cornea and the first polarization direction of light passing through the polarization direction rotation element are identical, and the polarization direction of the first b region of the contact lens and the second polarization direction of light passing through the polarization direction rotation element are identical.

21. In paragraph 14, An imaging device characterized in that a polarization direction display unit is additionally configured to display the polarization direction of the contact lens when the contact lens is worn on a human cornea.

22. In paragraph 14, An imaging device characterized in that the first a region and the first b region of the above contact lens have an annular shape.

23. In paragraph 14, An imaging device characterized in that a first image (left-eye image) and a second image (right-eye image) are alternately arranged on the image display element, and an optical film is additionally arranged at a predetermined interval in front of the polarizing element to spatially separate the first image and the second image, so that the first image is transmitted to a contact lens worn on the user's left eye and the second image is transmitted to a contact lens worn on the user's right eye.

24. In paragraph 23, An imaging device characterized in that the above optical film is a parallax barrier or a lenticular lens.

25. In paragraph 14, An imaging device characterized in that a near-eye optical element is additionally positioned adjacent to the polarizing element, which enables a user wearing the contact lens to view an external object and the image simultaneously.

26. In paragraph 25, An imaging device characterized in that the above-mentioned near-eye optical element includes a beam splitter and a semi-transparent concave mirror.

Images