TECHNICAL FIELD

The present invention relates to an optical device for augmented reality, and more particularly to an optical device for augmented reality that is capable of providing an augmented reality image to a user by using one or more reflective units having various shapes and the arrangement structure thereof.

BACKGROUND ART

Augmented Reality (AR) refers to technology that superimposes a virtual image, generated by a computer or the like, on a real image of the real world and then provides a resulting image, as is well known.

In order to implement augmented reality, there is required an optical system that allows a virtual image, generated by a device such as a computer, to be superimposed on an image of the real world and then allows a resulting image to be provided. As such an optical system, there is known a technology using an optical means such as a prism for reflecting or refracting a virtual image by using a head-mounted display (HMD) or a glasses-type device.

However, devices using the conventional optical system have problems in that it is inconvenient for a user to wear them because the configurations thereof are complicated and thus the weights and volumes thereof are considerable and in that the manufacturing costs thereof are high because the manufacturing processes thereof are also complicated.

Furthermore, the conventional devices have a limitation in that a virtual image becomes out of focus when a user changes focal length when gazing at the real world. To overcome this problem, there have been proposed technologies by using a configuration such as a prism capable of adjusting focal length for a virtual image or by electrically controlling a variable focal lens in response to a change in focal length. However, these technologies also have a problem in that a user needs to perform a separate operation in order to adjust focal length or in that hardware such as a separate processor and software for controlling focal length are required.

In order to overcome the problems of the conventional technologies, the present applicant has developed an apparatus that can implement augmented reality by projecting a virtual image onto the retina through the pupil using a reflective unit having a size smaller than that of the human pupil, as described in Related Art Document. According to this technology, the apparatus for implementing augmented reality is configured in the form of glasses and a reflective unit is disposed on the surface of a glasses lens or inside a glasses lens to reflect a virtual image generated by a display unit so that an image is formed on the retina through the pupil. Accordingly, a kind of pinhole effect is provided by deepening the depth of field, so that a clear virtual image may always be provided regardless of whether the user changes the focal length while gazing at the real world. However, this technology of the present applicant has a limitation in that the technology uses the circular point-symmetrical reflective unit, so that the difference in brightness between the central portion and the peripheral portion is relatively large, with the result that luminous uniformity is uneven.

RELATED ART DOCUMENT

Korean Patent No. 10-1660519 (published on Sep. 29, 2016)

DISCLOSURE

Technical Problem

The present invention has been conceived to overcome the above-described problems, and an object of the present invention is to provide an optical device for augmented reality that may improve luminous uniformity while deepening the depth of field and thus generating a pinhole effect by using one or more reflective units having one or more of various shapes and smaller than the pupil.

Furthermore, another object of the present invention is to provide an optical device for augmented reality that may improve luminous uniformity and widening field of view by appropriately disposing a plurality of reflective units.

Technical Solution

In order to overcome the above technical problems, the present invention provides an optical device for augmented reality, the optical device including: an optical means for transmitting at least part of visible light therethrough; and a reflective unit disposed on the surface of the optical means or inside the optical means, and configured to reflect image light corresponding to an image for augmented reality, output from an image output unit, toward the pupil of an eye of a user; wherein the reflective unit is formed in an asymmetric shape representing a shape other than a point-symmetric shape; and wherein the point-symmetric shape is a shape in which there is a specific point that allows the shape to be always the same for all rotation angles when the reflective unit is rotated around a specific point on the plane of the reflective unit, and the asymmetric shape is a shape that is not the point-symmetric shape.

In this case, it is preferable that the size of the reflective unit be 8 mm or less.

Furthermore, the size of the reflective unit may be the maximum length between any two points on the boundary line of the reflective unit.

Furthermore, the size of the reflective unit may be the maximum length between any two points on the boundary line of the orthogonal projection of the reflective unit projected onto a plane perpendicular to a forward direction from the pupil when the user gazes forward.

Furthermore, the size of the reflective unit may be the maximum length between any two points on the boundary line of the orthogonal projection of the reflective unit projected onto a plane perpendicular to a direction from the pupil to the reflective unit when the user gazes in the direction of the reflective unit.

Furthermore, the area of the reflective unit may be formed to have a value of 16π (mm2) or less.

Furthermore, the area of the reflective unit may be the area of the orthogonal projection of the reflective unit projected onto a plane perpendicular to a forward direction from the pupil when the user gazes forward.

Furthermore, the area of the reflective unit may be the area of the orthogonal projection of the reflective unit projected onto a plane perpendicular to a direction from the pupil to the reflective unit when the user gazes in the direction of the reflective unit.

Furthermore, the reflective unit may include first reflective unit and second reflective unit that are disposed at a predetermined interval in a vertical direction from the center of the image output unit and alongside each other in a downstream direction; and the first and second reflective units may be disposed such that they appear partially overlapping when viewed from the center of the image output unit toward the first and second reflective units.

Furthermore, the first and second reflective units may have different shapes.

According to another aspect of the present invention, there is provided an optical device for augmented reality, the optical device including: an optical means for transmitting at least part of visible light therethrough; and a reflective unit disposed on the surface of the optical means or inside the optical means, and configured to reflect image light corresponding to an image for augmented reality, output from an image output unit, toward the pupil of an eye of a user; wherein a through hole configured to pass the image light, output from the image output unit, therethrough is formed in the center of the reflective unit.

According to still another aspect of the present invention, there is provided an optical device for augmented reality, the optical device including: an optical means for transmitting at least part of visible light therethrough; and a reflective unit disposed on the surface of the optical means or inside the optical means, and configured to reflect image light corresponding to an image for augmented reality, output from an image output unit, toward the pupil of an eye of a user; wherein the reflective unit includes first reflective unit and second reflective unit that are disposed at a predetermined interval in a vertical direction from the center of the image output unit and alongside each other in a downstream direction; and wherein the first and second reflective units are disposed such that they appear partially overlapping when viewed from the center of the image output unit toward the first and second reflective units, and a through hole configured to pass the image light, output from the image output unit, therethrough is formed in the center of the first reflective unit.

Advantageous Effects

According to the present invention, there may be provided the optical device for augmented reality that may improve luminous uniformity while deepening the depth of field and thus generating a pinhole effect by using the one or more reflective units having one or more of various shapes and smaller than the pupil.

Furthermore, the present invention provides the optical device for augmented reality that may improve luminous uniformity and widening field of view by appropriately disposing the plurality of reflective units.

