KR102229498B1 - Optical apparatus and HMD having the same - Google Patents

Abstract

The lens unit of the head-mounted display device according to the present embodiment includes: a first lens having a positive power; A second lens having a positive power and arranged to have a center point contact with a rear end of the first lens; A third lens that has negative power and is bonded to the second lens to make surface contact with an opposite surface of the second lens; A fourth lens having negative power and spaced apart from the third lens by a predetermined distance; And a micro-display spaced apart from the fourth lens, wherein the first to fourth lenses are formed of a resin material.

Description

Optical module and head-mounted display apparatus having the same TECHNICAL FIELD [Optical apparatus and HMD having the same]

The present embodiment relates to an optical module and a head mounted display device having the same.

A typical example of wearable display devices is a head mounted display (HMD). The HMD is a display device worn on the face and is a device capable of viewing a large screen image regardless of the surrounding environment and the brightness of lighting. However, since it is worn directly on the face, it is necessary to consider the weight.

In order to realize a high-definition, large-screen image in the HMD, in the case of a conventional HMD having a wide image, as a lens structure of a binocular optical module, the diameter of the lens is increased, and a multi-lens in which a high-refractive glass material and a plastic material are mixed has been configured. Therefore, there is a problem that the weight of the device increases due to the weight of the lens made of glass.

The present embodiment provides a lens unit of a head mounted display device having an improved structure and material to reduce the weight of an optical system.

The lens unit of the head-mounted display device according to the present embodiment includes: a first lens having a positive power; A second lens having a positive power and arranged to have a center point contact with a rear end of the first lens; A third lens that has negative power and is bonded to the second lens to make surface contact with an opposite surface of the second lens; A fourth lens spaced apart from the third lens by a predetermined distance; And a micro-display spaced apart from the fourth lens, wherein the first to fourth lenses are formed of a resin material.

The third lens may have the thickest outer thickness and the thinnest center, and may have a center thickness within 2% of the diameter.

The second and third lenses may be provided as doublet lenses.

The micro-display may be any one of LCD, LCOS, DLP, and OLED.

Alternatively, the optical module according to the present embodiment may include a backlight unit; And a reflective member that transmits the light of the backlight unit to the micro-display and transmits the light of the micro-display.

The fourth lens may have a crescent shape that has the thickest central thickness and becomes thinner toward the outer periphery.

The fourth lens may include at least one aspherical surface.

The first lens may have a weaker power than the second to fourth lenses.

The optical module according to the present embodiment may be applied to a head mounted display device of any one of a binocular, bi-ocular, and mono-ocular type.

The head-mounted display device according to the present embodiment includes a body portion; A band portion coupled to the body portion and fixing the body portion to the user's head; A fixing portion coupled to the upper end of the body portion to support a user's forehead portion; And an optical module installed inside the body part and configured as described above.

Even if the material of the lens is changed to a plastic material, performance such as chromatic aberration and distortion of an image can be secured by forming a doublet lens structure.

In addition, since the thickness of the concave lens is formed to be within 2% of the diameter, the performance of the optical system can be maintained even if a high refractive lens made of a conventional glass material is not used.

In addition, it can be applied to both binocular and monocular head-mounted display devices, and can be used in micro-displays such as LCD and OLED, as well as display devices with a structure reflecting and projecting from backlight units such as LCOS and DLP, thus increasing design freedom. I can.

1 is a perspective view schematically showing an example of a head mounted display device having a lens unit according to the present embodiment;
2 is a schematic diagram illustrating an example of a lens unit of the head-mounted display device according to the present embodiment, and,
3 is a diagram illustrating a state in which a lens unit of the head-mounted display device according to the present embodiment is applied to a display device having a backlight unit.

Hereinafter, a lens unit of a head mounted display device will be described in detail according to an embodiment of the present invention. The accompanying drawings show exemplary forms of the present invention, which are only provided to describe the present invention in more detail, and thus the technical scope of the present invention is not limited thereto.

In addition, regardless of the reference numerals, the same or corresponding components are given the same reference numbers, and duplicate descriptions thereof will be omitted, and the size and shape of each component member shown for convenience of explanation may be exaggerated or reduced. have.

Meanwhile, terms including ordinal numbers such as first or second may be used to describe various components, but the components are not limited by the terms, and the terms refer to one component from another component. It is used only for distinguishing purposes.

1 is a perspective view schematically illustrating an example of a head mounted display device having a lens unit according to the present embodiment, and FIG. 2 is a schematic perspective view illustrating an example of a lens unit of the head mounted display device according to the present embodiment. FIG. 3 is a diagram illustrating a state in which a lens unit of the head-mounted display device according to the present embodiment is applied to a display device having a backlight unit.

As shown in FIG. 1, the head mounted display device (HMD) 1 according to the present embodiment includes a body part 2, a band part 3, a fixing part 4, and an optical module 100. ) Can be included.

The HMD(1) is a device that is mounted on the head and presents images directly in front of the user's eyes, and was the first to be made by Ivan Sutherland of the University of Utah in 1968. In early HMDs, a three-dimensional image was displayed on a monitor mounted on both eyes, and a corresponding image could be displayed by detecting the direction of the wearer through a device connected to the ceiling. Currently, the fifth generation HMD has been released, and content such as movies may be provided using wireless communication such as Bluetooth.

The body part 2 may be provided in an annular shape to close the user's head circumference and eyes, and may include a band part 3 that is adjustable in length so as to increase or decrease the diameter according to the size of the user's head circumference.

The band part 3 is connected to the body part 2 to support the upper and lower rear portions of the user's head, and for this purpose, it may have at least two or more branching structures.

The fixing part 4 is disposed on the front side of the body part 2 and may be disposed in a position facing the user's forehead part, so that it can support the weight of the HMD together with the band part 3. Since the fixing part 4 is in direct contact with the user's forehead, it is possible to form a contact surface made of a silicone or fabric material.

The optical module 100 is disposed in the inner space of the body 2 and may be disposed to face the user's eye E. According to the present embodiment, the optical module 100 is composed of first to fourth lenses 10 to 40 and a micro display 50 formed of a light-transmitting resin material such as plastic, as shown in FIG. 2. I can.

The first lens 10 may be disposed to be spaced apart from the user's eye E by a predetermined distance L, and may have positive power. The distance L may be increased or decreased according to the size of the optical system, but according to the present embodiment, it may be configured not to exceed 10 mm. In addition, the powder of the first lens 10 may be formed relatively weak compared to the powder of the second to fourth lenses 20 to 40. When the power of the first lens 10 is weakly formed as described above, the eye motion box of the user's eye observing the image of the micro-display 50 may be enlarged. Since the material of the first lens 10 is formed of a resin material as described above, the weight of the lens can be reduced when compared with a conventional glass material. The first lens 10 serves to collect the beam of the image of the micro-display 50 and send it to the user's eye E, and to form an image in the air. Meanwhile, the curvature of the surface of the first lens 10 facing the user's eye E may be formed to be smoother than the curvature of the surface facing the second lens 20.

The second lens 20 is formed to have positive power, and is bonded to the third lens 30 to be described later to secure performance such as chromatic aberration and distortion of an image. The curvature of the surface facing the third lens 30 may be smoother than the curvature of the surface facing the first lens 10 of the second lens 20, and the second lens 20 The first lens 10 may be configured to be in contact with only a partial section near the center. In this case, the first lens 10 and the second lens 20 may be in point contact or surface contact only in a partial section. In this embodiment, the first and second lenses 10 and 20 may be in point contact at the center.

The third lens 30 may be formed to have negative power, and may be bonded to the second lens 20 to form a doublet lens. The third lens 30 may be formed to have the thickest outer thickness and the thinnest center of the third lens 30. In this case, the central thickness t of the third lens 30 may be configured to be 2% or less with respect to the size of the diameter D of the third lens 30.

In addition, a surface of the third lens 30 facing the second lens 20 and a surface facing the fourth lens 40 may be both concave, and the surface facing the second lens 20 The curvature of may be configured to correspond to a curvature of a surface of the second lens 20 facing the third lens 30.

In addition, a straight section of a predetermined length may be provided on a surface of the third lens 30 facing the fourth lens 40 along with a concave groove portion accommodating a part of the fourth lens 40.

Meanwhile, the second and third lenses 20 and 30 may also be formed of a resin material such as plastic, like the first lens 10. In addition, surfaces of the second and third lenses 20 and 30 facing each other may be provided as curved surfaces, and curvatures thereof may be provided to correspond to each other, and surfaces in contact with each other may be configured to be in contact with each other. . In this case, the second and third lenses 20 and 30 may be adhered to each other through a separate adhesive member, or may be arranged in close contact without an adhesive member.

The fourth lens 40 may be disposed to be spaced apart from the third lens 30 by a predetermined distance. The thickness of both ends of the fourth lens 40 may be thinner than the thickness of the center, and may be provided in an approximately crescent shape. In addition, the fourth lens 40 may have at least one aspherical surface, and optical performance may be optimized through such an aspherical surface. In addition, the upper fourth lens 40 may be spaced apart from the third lens 30 by a predetermined distance, and a surface of the fourth lens 40 facing the concave portion of the third lens 30 is 3 It may be disposed inside the concave portion of the lens 30.

Meanwhile, the optical module 100 according to the present embodiment may be applied to the head-mounted display device 1 of any one of a telephoto method (binocular), a binocular method (bi-ocular), and a mono-ocular method.

For example, when configured in a binocular manner, a pair of optical systems configured as shown in FIGS. 2 and 3 may be provided and disposed to correspond to the user's eyes E.

The micro-display 50 may be provided with any one of LCD, LCOS, DLP, and OLED, and may be spaced apart from the fourth lens 40 by a predetermined distance. LCD (Liquid Crystal Display) is a structure in which liquid crystal is inserted and sealed between patterned glass substrates, and a transmission type is common. Since LCD is difficult to emit light itself, a separate backlight unit is required. LCOS (Liquid Crystal On Silicon) is a device in which the configuration of a pixel electrode is formed on a silicon substrate, and is manufactured in a reflective type. When the display device is manufactured in a reflective type, since the pixel driving electrode does not block light, the light efficiency can be increased, so that a bright system can be configured. In addition, since pixels are fabricated on a silicon substrate using a semiconductor process, high resolution is easy. OLED (Organic Light-Emitting Diode) is a thin-film light-emitting diode in which the light emitting layer is made of an organic compound. Because OLED pixels emit light directly, the expression range of light is larger than that of LCD, and the level of black is excellent because there is no need for backlight. In addition, it has 1000 times faster response speed compared to LCD and can be bent.

Meanwhile, although not shown, the micro-display 50 may be configured as an image image obtained by re-imaged an indirect image using a rear or front projection method.

If the micro-display 50 is an LCD, as shown in FIG. 3, a backlight unit 60 needs to be further provided, and the reflective member 61 is on the optical path of the backlight unit 60. It is installed to transmit light from the backlight unit 60 to the micro-display 50 side. In this case, the reflective member 61 may transmit the light from the backlight unit 60 to the micro-display 50 by totally reflecting it, and transmit the light including the image of the micro-display 50. However, the present invention is not limited thereto, and it is possible to adjust the position of the reflective member 61 so as not to interfere with the optical path through which the image of the micro-display 50 is transmitted.

According to the present embodiment as described above, since the first to fourth lenses 10 to 40 constituting the optical module 100 are formed of a resin material that is relatively lighter than the conventional glass material, the weight of the HMD can be reduced. have. In addition, even when applied to the micro-display 50 supporting high resolution, since the second and third lenses 20 and 30 are composed of doublet lenses, the optical system is optimized so that chromatic aberration and distortion of the image do not occur. It is possible.

In addition, since the optical system can be configured regardless of the type of the micro display 50, it can be applied to various image providing means. In addition, it can be applied regardless of the monocular or binocular optical system.

Although the embodiments according to the present embodiment have been described above, these are merely exemplary, and those of ordinary skill in the art will appreciate that various modifications and equivalent ranges of embodiments are possible therefrom. Therefore, the true technical protection scope of this embodiment should be determined by the following claims.

One; Head mounted display device 2; Body
3; Band part 4; Fixed part
10; A first lens 20; Second lens
30; Third lens 40; 4th lens
50; Micro display 60; Backlight unit
61; Reflective member 100; Optical module

Claims (10)

A first lens having a positive power;
A second lens having a positive power and arranged to have a center point contact with a rear end of the first lens;
A third lens that has negative power and is bonded to the second lens to make surface contact with an opposite surface of the second lens;
A fourth lens spaced apart from the third lens by a predetermined distance; And
Includes; a micro-display spaced apart from the fourth lens,
The first to fourth lenses are formed of a resin material,
The first lens, the optical module of the head mounted display device having a weaker power than the second to fourth lenses.
The method of claim 1, wherein the third lens,
The outer thickness is the thickest and the center is the thinnest.
The optical module of the head-mounted display device whose center thickness is within 2% of its diameter.
The method of claim 1,
The optical module of the head-mounted display device wherein the second and third lenses are doublet lenses.
The method of claim 1, wherein the micro-display,
An optical module for a head mounted display device that is any one of LCD, LCOS, DLP and OLED.
The method of claim 1,
Backlight unit; And
The optical module of the head-mounted display device further comprising a; reflective member that transmits the light of the backlight unit to the micro-display and transmits the light of the micro-display.
The method of claim 1, wherein the fourth lens,
The optical module of a head-mounted display device with a crescent shape that has the thickest center thickness and gets thinner toward the outside.
The method of claim 1, wherein the fourth lens,
An optical module of a head-mounted display device including at least one aspherical surface.
delete The method according to any one of claims 1 to 7,
An optical module of a head-mounted display device applied to a head-mounted display device of any one of a binocular, bi-ocular, and mono-ocular system.
Body part;
A band portion coupled to the body portion and fixing the body portion to the user's head;
A fixing portion coupled to the upper end of the body portion to support a user's forehead portion; And
A head-mounted display device comprising: an optical module installed inside the body and configured as described in any one of claims 1 to 7.

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