KR20170040538A - Optical System and Display Device Using the Same - Google Patents

Abstract

The present invention relates to a slim optical system which can easily control a light exit range, and a display device applying the same. The optical system of the present invention has an exit pattern on one surface by having a plate-shaped waveguide a matrix, and an incident pattern and a plane collimator horizontally arranged with the exit pattern, thereby realizing the slim optical system at a thickness level of the waveguide.

Description

TECHNICAL FIELD [0001] The present invention relates to an optical system and a display device using the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical system, and more particularly, to a slim optical system and a display device using the optical system.

The conventional 2D image system provides the plane image, but the 3D image system is the ultimate image realization technology in terms of showing the actual image information of the object to the observer.

Techniques such as stereoscopy, holography, and integral imaging have been researched and developed as methods for reproducing 3D stereoscopic images. Among them, the holographic method is a method of observing the holography produced by using a laser as a light source and feeling the same stereoscopic image as a real object without attaching special glasses. Therefore, the holographic method has excellent stereoscopic effect and is known to be the ideal method for observers to feel stereoscopic images without fatigue.

The holographic method uses the principle of recording and reproducing an interference signal obtained by superimposing light (object wave) reflected from an object and light (reference wave) having coherence. A hologram is a technique in which an interference fringe formed by contacting an object wave scattered by an object with a highly coherent laser light with a reference wave incident from another direction is recorded on the scattered film. When an object wave and a reference wave meet, an interference fringe due to interference is formed. The amplitude and phase information of the object are also recorded in this fringe pattern. Holography refers to irradiating reference light on the recorded interference fringes and restoring the information recorded in the holograms into a three-dimensional image.

On the other hand, the laser light used for the holographic method is a point light source, and the emission region is very narrow, and a collimation system that receives light from the laser and emits it as parallel light is used to expand the region of the straight- It is used for wave generation.

Hereinafter, various examples of the conventional collimation system will be described with reference to the drawings.

Figures 1A and 1B show a conventional collimation system.

In the collimation system of FIG. 1A, the collimation system is constituted by disposing the point light source 30 at one point and arranging the collimation lens 35 at a constant focal distance therefrom. Thus, light is emitted from the entire emission surface of the collimation lens 35 in the same direction as the straight-line light emitted from the point light source 30.

The collimation system shown in FIG. 1A requires a space as much as the focal distance between the point light source and the collimation lens, and the collimation lens has a physical curvature, .

FIG. 1B shows a collimation system in which the point light source 40 is positioned at a focal point, and a reflecting mirror 50 is provided in a form surrounding the point light source 40. In this configuration, the light emitted from the light source 40 at the focal position is emitted in a straight-ahead light form at a certain point on the reflector.

The collimation system of FIG. 1B has a height of the parabolic reflector 50 so as to correspond to the focal distance for straight ahead, which is also impossible to integrate.

That is, the conventional collimation systems require a physical space of more than a certain level in order to provide a collimation lens or a reflector.

On the other hand, the collimation system has directivity and can be used for a display device capable of adjusting the viewing range in addition to the holography method described above. For example, it can be used for a privacy display for giving display information to a specific spectator, or for a multi-display device for displaying different images in different viewing ranges.

However, when a collimation system described above is applied to a flat display device for integration in recent years for a specific directivity, a space of more than a certain volume is required and integration is impossible.

Further, in the case of the conventional collimation system, the relative position between the light source and the optical element can be well defined, and the collimation function can be performed. In addition to the weight of the lens and the reflector itself, The structure is required to be fixed in order to increase the weight of the entire system.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a slim optical system and a display device using the optical system.

According to an aspect of the present invention, there is provided an optical system comprising a flat plate waveguide as a matrix, an output pattern provided on a surface of the waveguide, and a light incident pattern and a planar collimator arranged in a lateral arrangement, The light source unit can be realized.

Such a light source unit is combined with a display panel in the form of a backlight unit or a front light unit, and the display device is also integrated to realize a display device of a super thin film type.

It is possible to realize a transparent display device by using a transparent waveguide, and it is possible to realize a transparent display device by using a grating shape of an output pattern provided on a waveguide, a direction of incident light entering from an incident pattern, or a focal distance relationship between a plane collimation pattern and a light source, The shape can be controlled by selecting from divergent light, parallel light or condensed light.

The optical system of the present invention includes a planar waveguide, a light incidence portion including an incident pattern on a part of the surface adjacent to the side portion of the waveguide and transmitting light having an expanded propagation width of incident light coming from the light source, A planar collimator for transmitting the light expanded in the incident direction to the waveguide through the linear light, and a light output unit for outputting the linear light to the upper side of the waveguide.

The light incident portion, the plane collimator, and the light output portion may be divided into areas on the first surface of the waveguide.

And may further include a substrate on a second surface of the waveguide.

In addition, the incident pattern may be a holographic optical element (HOE) attached to the waveguide surface or may be defined as surface grating or volume grating on the waveguide.

The light source may be a laser with good coherence.

The light source may include a red laser, a green laser, and a blue laser for introducing red light, green light, and blue light into different regions of the incident pattern.

The waveguide may have a laminated structure including a core layer having a first refractive index n1 and a first cladding layer having a second refractive index n2 lower than the first refractive index.

The planar collimator may include a cladding pattern layer having a third refractive index n3 greater than the second refractive index and smaller than the first refractive index on the waveguide.

In this case, the planar collimator may further include a second clad layer of a fourth refractive index (n4) that fills the periphery of the clad pattern layer on the waveguide and is smaller than the first and third refractive indexes.

The planar collimator may include the clad pattern layer as a positive lens in a plane.

The planar collimator may include the clad pattern layer as a negative lens in a plane.

The light output unit may be an emission pattern having a surface grating and a volume grating that emits the light coming from the plane collimator to one of the condensed light, the parallel light and the divergent light on the upper side of the waveguide.

According to another aspect of the present invention, there is provided an optical system including: a planar waveguide; a light incidence part including an incident pattern on a part of the surface adjacent to the side of the waveguide and transmitting light having an expanded traveling width of incident light coming from the light source; A planar collimator for transmitting light having a traveling width expanded by the light incidence portion to the waveguide so as to pass through the waveguide, and a light output portion for emitting the linear light to the upper side of the waveguide, And a light guide plate is further provided on the second surface of the waveguide.

In this case, the light incidence portion and the planar collimator may be located on opposite sides of the light guide plate.

And a waveguide light incident portion on the first surface of the waveguide so as to overlap the planar collimator.

Wherein the light guide plate transmits the light entering the light incidence portion to the planar collimator, the light transmitted from the planar collimator to the waveguide light incidence portion is coupled, the coupled light is transmitted through the wave guide, And the waveguide can be emitted from the upper side of the waveguide.

The waveguide may include a first cladding layer having a first refractive index and a second cladding layer having a second refractive index lower than the first refractive index, and the first cladding layer may be in contact with the light guide plate. The light coupled at the waveguide light incidence portion may be transmitted through the core layer of the waveguide.

The optical system described above can be used as a backlight unit provided below the light receiving type image panel. In this case, the light receiving region of the light receiving type image panel may correspond to the region of the light emitting portion.

Alternatively, the above-described optical system can be used as a front light unit provided on the upper side of the reflection type image panel. The incident area and the reflection area of the reflection type image panel may correspond to the area of the light output part.

The optical system of the present invention and the display device using the same have the following effects.

First, the optical system of the present invention can realize a light source unit that is slim to a waveguide thickness level by using a planar waveguide as a matrix and having an output pattern on one surface thereof and arranging an incident pattern and a planar collimator in a lateral arrangement thereof have. Further, all the upper side of the waveguide is used as an emission surface, and the linearity can be improved.

Second, the light source unit is combined with the display panel in the form of a backlight unit or a front light unit, and the display device is also integrated, thereby realizing a super thin film type display device.

Thirdly, a transparent display device can be realized by using a transparent waveguide, and a grating shape of an emission pattern provided on a waveguide, a direction of incident light entering from an incident pattern, or a focal distance relationship between a plane collimation pattern and a light source, It is possible to select and control the shape of light output from divergent light, parallel light or condensed light. Thus, an ultra-thin holographic display device, a non-spectacles 3D display device, or a privacy display device can be implemented according to the appearance of the display device.

Fourth, it is possible to realize the light source unit only by the incidence pattern, the emission pattern, and the collimation pattern of the waveguide and the horizontal arrangement without the optical sheet.

Figures 1A and 1B show a conventional collimation system.
2 is a perspective view of an optical system according to a first embodiment of the present invention;
3 is a cross-sectional view taken along line I-I 'of FIG. 2;
FIGS. 4A and 4B are a cross-sectional view and a perspective view showing the operation of the light incidence portion of the optical system of FIG. 2;
Figs. 5A and 5B are a cross-sectional view and a perspective view showing the operation of another embodiment of the light incidence portion of the optical system of Fig. 2;
6A and 6B are perspective views showing optical paths when light is incident on the center of the HOE of the light incidence portion of FIG. 2;
FIGS. 7A and 7B are perspective views showing optical paths when light is incident on the HOE side of the light incidence portion of FIG. 2;
8A and 8B are a cross-sectional view and a perspective view showing the operation of the planar collimator of FIG. 2;
Fig. 9 is a view showing a wavefront of the plane collimator of Fig. 2; Fig.
FIGS. 10A to 10C are diagrams showing changes in the wavefront of light according to the widths of the high refractive index layers of the plane collimator on the II-II 'line, III-III' line and IV-IV line in FIG.
11A and 11B are cross-sectional views showing an embodiment of a planar collimator of the optical system of the present invention.
12A and 12B are a cross-sectional view and a perspective view showing the operation of the light output portion of the optical system of FIG. 2;
13A to 13C are perspective views showing condensed light, parallel light, and divergent light output form according to the grating shape of the light output portion of the optical system of the present invention.
FIGS. 14A to 14D are perspective views showing condensed light, parallel light, and divergent light output form according to the form of light entering from the plane collimator of the optical system of the present invention. FIG.
15A and 15B are cross-sectional views showing various shapes of an emission pattern of the optical system of the present invention.
16 is a perspective view showing an optical system according to a second embodiment of the present invention.
Fig. 17 is a sectional view of Fig. 16; Fig.
18 is a sectional view showing a display device of the present invention in which the optical system of Fig. 2 is applied as a backlight unit.
19 is a perspective view showing a display device of the present invention in which the optical system of Fig. 2 is applied as a front light unit; Fig.
20 is a sectional view of FIG. 19;
FIG. 21 is a sectional view showing a display device of the present invention in which the optical system of FIG. 16 is applied as a backlight unit.
Fig. 22 is a perspective view showing a display device of the present invention in which the optical system of Fig. 16 is applied to a front light unit. Fig.
Fig. 23 is a sectional view of Fig. 22; Fig.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Like reference numerals throughout the specification denote substantially identical components. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description, a detailed description of known technologies or configurations related to the present invention will be omitted when it is determined that the gist of the present invention may be unnecessarily obscured. The component names used in the following description are selected in consideration of easiness of specification, and may be different from the parts names of actual products.

The optical system of the present invention to be described below can have a collimation characteristic, a condensing characteristic, or a divergent characteristic, so that the outgoing light control is easy, It is not limited to the characteristics and is called an optical system.

Further, the optical system of the present invention can be used as a light source unit required for a light-receiving-type display apparatus, by utilizing the light-outgoing characteristic thereof. At this time, the light source unit can be either a backlight unit or a front light unit, and the front and back arrangement of the light source units can be different depending on the type of the display panel to be used.

* First Embodiment *

FIG. 2 is a perspective view of an optical system according to a first embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along line I-I 'of FIG.

2 and 3, the optical system of the present invention includes a planar waveguide 1000, an incident pattern 130 on a part of the surface adjacent to the side of the waveguide 1000, A light coupler A for transmitting light having an expanded propagation width of incident light and a planar collimator for transmitting the light having a progressive width expanded in the light incidence portion to the waveguide through a straight- a plane collimator (B), and a light extraction component (C) for emitting the linear light to the upper side of the waveguide.

In the illustrated first embodiment, the light incident portion A, the plane collimator B, and the light output portion C are defined on the first surface (upper surface) of the waveguide 1000, do.

The optical system according to the first embodiment of the present invention is used as a kind of backlight unit, and is a light source unit that uses the waveguide 1000 as an actual configuration and transmits light upward without additional optical sheets.

Here, the waveguide 1000 is an optical waveguide in the form of a flat plate, serving as a skeleton that forms the basis of the overall structure of the optical system, and functions to optically connect components.

The incident pattern 130 and the output pattern 150 may be provided on the surface of the waveguide 1000 or may be formed on the waveguide 1000 as a separate layer.

For example, when the incident pattern 130 is attached to the waveguide 1000 as a separate layer, the incident pattern 130 may be a film type holographic optical element (HOE).

When the incident pattern 130 is formed directly on the surface of the waveguide 1000, it may be defined as surface grating or volume grating on the waveguide 1000. In the case of surface grating or volume grating, the incident pattern 130 may be formed on the waveguide 1000 as a separate cladding layer (having a lower refractive index than the core layer 120).

In this case, a light source for transmitting incident light is disposed above or below the incident pattern 130, for example, a laser (not shown). The reason for using the laser is that the light emitted from the laser is all in phase and has good coherence. If another light source is used, a slit pattern may be further provided to induce coherence. When the light source is positioned below the incident pattern 130, a light source is provided below the wave guide 1000.

In addition, the incident pattern 130 has a relatively small width as compared with the planar collimator B. This is because a light source such as a laser is a point light source and the incident area is small.

The light incident portion A including the incident pattern 130 expands the propagation width of incident light in the vertical direction and transmits the incident light to the horizontal plane collimator B. The incident pattern 130 is incident on the plane collimator B, An object such as the width of the plane collimator B is recorded, and the incident light is accurately transmitted in correspondence with the width of the plane collimator B.

The incident pattern 130, the emission pattern 150 and the plane collimator B are all formed on the waveguide 1000. In this case, the waveguide 1000 is formed of the core layer having the first refractive index n1, (110) and a first cladding layer (120) having a second refractive index (n2) lower than the first refractive index.

The planar collimator B has a separate cladding layer pattern 140 on the waveguide 1000 to select and deliver one of the linearly transmitted light, converged light, or divergent light to the transmitted light transmitted to the light emitting unit . Thus, the directivity of the light emitted from the light output unit can be different.

Alternatively, the plane collimator B may supply the linear light to the light output portion C in the lateral direction, and may change the directivity of the light emitted to the light output portion by changing the type of the output pattern 150 provided in the light output portion It may be different.

The planar collimator B collimates in the flat plate of the waveguide 1000 and is provided on the surface of the waveguide 1000 instead of the conventional lens or reflector, (positive lens) or divergent lens (negative lens). For example, when the planar collimator B is a single lens, the converging lens has the shape of the convex lens and the concave lens of the diverging lens.

The cladding layer pattern 140 of the planar collimator B and the incident pattern 130 and the emission pattern 150 may be located on the same layer on the waveguide 1000. In this case, air may be filled in the clad layer pattern 140, the incident pattern 130, and the output pattern 150 without any other material, or may be transparent, and the clad layer pattern 140, Another clad layer of a material having a refractive index lower than that of the outgoing pattern 130 may be filled.

The grating of the output pattern of the light output portion may be formed in the shape of a surface grating or a volume grating as described above in the incident pattern, and the shape may be either a curved shape or a straight shape. The shape of the emission pattern can be adjusted in consideration of the directivity of light.

The light output portion C emits the light transmitted in the lateral direction to the outside, and the direction is the vertical direction of the upper portion. The light output portion C may use a cladding layer on the waveguide surface as an emission pattern, or may be formed by attaching an emission pattern to a cladding layer having a different refractive index.

Hereinafter, the optical system of the first embodiment of the present invention will be described in detail with reference to the drawings.

4A and 4B are a cross-sectional view and a perspective view showing the operation of the light incidence portion of the optical system of FIG.

4A and 4B, the incident pattern 130 is formed only on the surface of a part of the side portion of the waveguide 1000, and the remaining region of the light incident portion A excluding the incident pattern 130 is formed on the waveguide 1000 There are no patterns or substances in the. A separate clad layer may be filled around the incident pattern 130 to be planarized to the surface of the incident pattern 130. Since light is transmitted along the core layer 120 of the waveguide 1000, The separate cladding layer does not function optically.

The light emitted from the incident pattern 130 is transmitted to the planar waveguide 1000 in accordance with the width of the planar collimator B and the incident pattern 130 diffuses light to secure luminance uniformity.

The incidence pattern 130 is a holographic optical element or a volume grating on a film basis. Generally, light incident vertically from a point light source such as the laser 170 is horizontally bent below the wave guide 1000 And the waveguide 1000 is first made incident on the waveguide 1000.

In the optical waveguide 1000, the evanescent field region of the weak energy may be included in the cladding layer, but the core region of the center energy may be included in the waveguide 1000, The core layer 120 of FIG.

In this case, when the HOE is used as the incident pattern 130, information such as the width of the plane collimator is recorded, so that the incident light can be exactly equal to the width of the plane collimator when it is transmitted to the plane collimator.

When the volume grating is used as the incident pattern 130, the incident pattern 130 is formed with a slit having a predetermined depth of inclination.

4A and 4B illustrate incidence patterns that can be provided at the incidence of monochromatic light.

5A and 5B are a cross-sectional view and a perspective view showing the operation of another embodiment of the light incidence portion of the optical system of FIG.

5A and 5B, the light incidence portion A may correspond to different positions of the red, green, and blue laser light sources and may have incident patterns 130a, 130b, and 130c at different positions. For example, the incident patterns 130a, 130b, and 130c may have corresponding gratings at different points with respect to incident light of corresponding color emission, or may include different HOEs for red, green, and blue, respectively.

In this case, it is preferable that the light output portion C also divide the emission pattern 150 for red, green, and blue light output respectively into different forms of volume grating or surface grating, So that the emission directions of the monochromatic light emerging in the path can be individually controlled.

In addition, as shown in the drawing, the incident patterns 130a, 130b, and 130c and the emission pattern 150 may be formed in a laminated structure in addition to the two areas.

On the other hand, the steering of the internal light can be made different by arranging the point light sources on the incident pattern 130.

FIGS. 6A and 6B are perspective views showing a light path in the case where light is incident on the center of the HOE of the light incidence portion of FIG. 2, and FIGS. 7A and 7B are views of the light incident portion of the light incidence portion of FIG. Fig.

6A, when the light source 100 corresponds to the center of the HOE as the incident pattern 130 of the light incidence portion, the light vertically incident from the light source 100 is recorded on the plane collimator B as an object And as shown in FIG. 6B, parallel light is emitted from the plane collimator (B).

7A, the light incident vertically from the light source 101 corresponds to the length of the plane collimator B when the light source 101 corresponds to one side of the HOE as the incident pattern 130 of the light incidence portion, 6A. As shown in FIG. 7B, in the plane collimator B, when light is transmitted, at a position corresponding to the incident pattern 130 of the light source 101, And is inclined in a direction toward the center of the plane collimator (B). That is, when the light source 101 is shifted with respect to the center of the incident pattern, the optical system can be configured to transmit light in a constant inclined state and to steer in a specific direction through the configuration of FIGS. 7A and 7B have.

Here, the light sources 100 and 101 are a kind of point light source such as a laser, and can irradiate incident light to a limited region of the incident pattern 130. The direction in which the light sources 100 and 101 irradiate the incident light may be from the lower side to the upper side of the wave guide as shown in Figs. 2 to 3. Alternatively, as shown in Figs. 6A to 7B, It is possible.

8A and 8B are a cross-sectional view and a perspective view showing the operation of the planar collimator of FIG. FIG. 9 is a view showing a wavefront of the plane collimator of FIG. 2. FIG. FIGS. 10A to 10C are diagrams showing changes in the wavefront of light according to the widths of the high refractive index layers of the plane collimator on the II-II 'line, III-III' line and IV-IV line in FIG.

As shown in FIGS. 8 and 9, the in-plane collimator (B) of the present invention can replace a conventional collimation lens or a reflector. The in-plane collimator B includes a light incident portion, And a cladding pattern layer 140 is formed on the substrate.

The third refractive index n3 of the cladding pattern layer 140 is smaller than the first refractive index n1 of the core layer 120 of the waveguide 1000 and is smaller than the second refractive index n2 of the first cladding layer 110. [ Lt; / RTI >

As shown in Fig. 9, the clad pattern layer 140 is a planar shape of a kind of a converging lens (positive lens). The lens used as the clad pattern layer 140 has a shape of the convex lens in the case of a single lens.

10A to 10C, the periphery of the clad pattern layer 140 may be filled with the second clad layer 160, and the second clad layer 160 may be formed of the core layer 120 and the clad pattern layer 140. [ (N4) lower than the first refractive index (140).

That is, the fourth refractive index n4 of the second cladding layer 160 is lower than the refractive index n3 of the cladding pattern layer 140. In some cases, the second cladding layer 160 may be filled with air without filling the material having a specific refractive index n3, thereby inducing a difference in refractive index between the cladding pattern layer 140 and the cladding layer.

8A, since the edge portion of the waveguide 1000 and the central portion of the waveguide 1000 have different widths on the plane of the shape of the clad pattern layer 140, The area through which the light passes through the clad pattern layer 140 is changed, and therefore, another wavefront conversion section is obtained as shown in Figs. 10A to 10C. The wavefront conversion section is between the curved wavefront section and the plane wavefront section, and converts the wavefront shape from the curved surface to the plane. At this time, the wave of the light having the normal effective wavelength passes through the wavefront conversion section in the curved wavefront section and the plane wavefront section, and the effective wave length is reduced due to the high refractive index, thereby changing the wavefront. Accordingly, the light that has been diffused by the plane collimator in the light incidence portion passes through the plane collimator, and can be emitted as parallel light with good collimation.

11A and 11B are cross-sectional views showing an embodiment of a planar collimator of the optical system of the present invention.

11A is a plan view of the planar collimator B in which the main surface of the clad pattern layer 140 is left empty to fill the air.

11B shows a second clad layer 160 of a fourth refractive index n4 which is smaller than the third refractive index n3 of the clad pattern layer 140 around the clad pattern layer 140 of the planar collimator B.

However, the planar collimator is not limited to this. In the embodiment of FIGS. 11A and 11B, an intermediate clad layer may be further provided between the clad pattern layer 140 and the core layer 120, 11b may further include a top clad layer (not shown) on the clad pattern layer 140 and the second clad layer 160.

In any case, the refractive index is relatively higher than that of the cladding layer in which the cladding pattern layer 140 is additionally provided. When the wave front passes through the cladding pattern layer 140, the light of the curved wave- And is transmitted as a linear wavefront characteristic.

12A and 12B are a cross-sectional view and a perspective view showing the operation of the light output portion of the optical system of FIG.

As shown in FIGS. 12A and 12B, light transmitted through the plane collimator B to the waveguide 1000 with linear light can be emitted upward of the emission pattern 150. FIG.

In this outgoing pattern 150, surface grating or volume grating can be applied in order to change the direction of light transmission from transverse to vertical. Thus, the grating diffraction distribution can be adjusted over the whole area of the emission pattern 150, and the luminance uniformity of the light output portion can be ensured.

The shape of the light emitted from the light output unit may be any of condensing, parallel light, and divergent light, and it may be adjusted through a grating pattern of a surface grating or a volume grating, or a focal length of a light source with respect to a parallel light collimator Can be selected.

FIGS. 13A to 13C are perspective views showing condensed light, parallel light, and divergent light output patterns according to the grating shape of the light output portion of the optical system of the present invention. FIG.

Figs. 13A to 13C define the shape of the emission pattern when straight-line light emerges from the plane collimator B. Fig.

13A shows a curve grating 151 applied in the form of a surface grating for condensing. Although the curve grating is shown to be directed toward the center of the emission pattern 150, the curvature of the curve grating 151 may be different depending on the required degree of condensation, Or the pattern shape at the center and the edge may be different.

As such, when the curved grating 151 is applied for focusing, the optical system to which the curved grating 151 is applied can be used as the light source unit of the privacy display device.

13B shows a linear grating 152 applied to the surface grating for emitting parallel light.

Such a parallel light output may be used as a light source unit when a specific collimation is required in accordance with the viewer's eyes, for example, a 3D display device.

FIG. 13C shows a curve grating 153 applied in the form of a surface grating for divergent light. Although the curved grating is shown to be directed to the outside of the emission pattern 150, it is not limited thereto, and the curvature of the curved grating 153 may be different according to the degree of condensation required, Or the pattern shape at the center and the edge may be different.

In the meantime, all of the above-described examples are exemplified as surface gratings, but the present invention is not limited to this, and a volume grating may be applied to the emission pattern 150 to control the form of condensation, parallel light, and divergence of emitted light.

The volume grating may have a shape having a slope at a certain depth of the emission pattern 150.

In addition, the surface grating and the volume grating can be applied to a certain depth in the surface or layer of the waveguide 1000 or the waveguide 1000 by defining the emission pattern 150 as a separate layer, can do.

Hereinafter, the shape of the outgoing pattern to be described hereinafter indicates when the light coming from the plane collimator B already has the directionality.

FIGS. 14A to 14D are perspective views showing condensed light, parallel light, and divergent light outgoing light according to the form of light entering from the plane collimator of the optical system of the present invention. FIG.

14A to 14D show that the output pattern 150 is provided with the linear grating 252 and the shape of the light entering the output pattern 150 from the plane collimator 140 in the case of such a linear linear grating 252 The shape of the outgoing light in the outgoing pattern 150 is changed.

14A, when the point light source is located out of the focal point of the planar collimator B having the convex lens-shaped clad pattern layer 140, light is emitted from the plane collimator B to the outgoing pattern 150 And the converged light comes out of the form in which light is emitted to one point from the outgoing pattern 150 upward.

On the other hand, when a point light source is provided at the focus of the clad pattern layer 140 of the planar collimator B as shown in FIG. 14B, the planar collimator B is directly transmitted from the planar collimator B to the waveguide 1000, ) In the form of parallel light. In this case, the outgoing characteristic of the clad pattern layer 140 emits linear light.

14C, when the point light source is located inward from the focal point of the planar collimator B having the lens-shaped clad pattern layer 140, light is emitted from the plane collimator B to the output pattern 150 And the divergent light has a diverging characteristic in the waveguide 1000 and the divergent light is emitted from the output pattern 150 upward.

Fig. 14D shows that the lens of the planar collimator B has negative characteristics, that is, divergence characteristics, in which the clad pattern layer 145 is a concave lens. In this case, the light source 100 may be located at the focal point of the clad pattern layer 145 when the clad pattern layer 145 has a diverging characteristic.

On the other hand, as described above, the emission pattern 150 is formed by surface grating or volume grating.

15A and 15B are cross-sectional views showing various shapes of an emission pattern of the optical system of the present invention.

15A shows a kind of surface grating, which shows that an output pattern 150 is formed by a set of gratings 260a spaced apart from the surface of the waveguide 1000. FIG.

15B shows a kind of volume grating. In the waveguide 1000, a plurality of patterns 260b such as slits having a predetermined depth and inclined in a film having a predetermined thickness are provided, .

For example, the grating shape may be a curve, a straight line, a shape that is gradated from one edge to the opposite edge on the plane of the light output portion of the waveguide, or from the center to the outer edge of the waveguide, Several variations will be possible.

Meanwhile, in the optical system according to the first embodiment of the present invention, a substrate may be further provided below the waveguide 1000 to prevent dust or foreign matter from adhering to the waveguide and thereby preventing optical characteristics from being impaired. At this time, the substrate may be provided in a shape corresponding to the area of the waveguide or slightly larger than the area of the waveguide so that the entire lower surface of the waveguide is located on the substrate.

In some cases, the lower first clad layer 110 of the waveguide 1000 may be used as a substrate.

In addition, in the optical system according to the first embodiment of the present invention, the thickness of the waveguide 1000 can be 1 占 퐉 to 99 占 퐉, the total thickness of the flat plate is less than 100 占 퐉, An optical system can be realized. In addition, light can be emitted only by the waveguide structure, the input / output pattern, and the plane collimator, and the light source unit can be realized without using the optical sheet.

The shape of the outgoing light can be adjusted by adjusting the position of the point light source from the incoming / outgoing pattern or the shape of the plane collimator or from the plane collimator to one of condensing, parallel light and divergent light, It is possible to realize an optical system having emission characteristics.

The optical system described above can be realized as a light source unit of ultra high transmittance because it has transparency when the waveguide and the emission pattern are made transparent, thereby realizing a transparent display device in which the light source unit is applied to the light receiving element .

* Second Embodiment *

Hereinafter, a second embodiment of the present invention will be described. The second embodiment of the present invention solves the problem that the structure of the first embodiment of the present invention is inevitable in a display device in which a region other than an emission pattern acts as a dead region and can be slimmed but a planar dead region is inevitable.

16 is a perspective view showing an optical system according to a second embodiment of the present invention, and Fig. 17 is a sectional view of Fig.

16 and 17, in the optical system according to the second embodiment of the present invention, the light guide plate 330 is positioned below the wave guide 1000, the light incidence portion is positioned on one surface of the lower side of the wave guide, And the configuration of the collimator is positioned on the opposite side of the light incidence portion.

In this case, the first surface, which is the upper surface of the waveguide 1000, has a light output portion, and the light guide plate 330 is disposed on the second surface, which is the lower surface of the waveguide 1000.

The incident pattern 310 and the plane collimator pattern 320 of the light incidence portion A are located on opposite sides of the light guide plate 330 facing each other.

The waveguide 1000 may further include a waveguide light incidence part 350 on the first surface of the waveguide 1000 so as to overlap with the planar collimator pattern 320.

The light guide plate 330 functions as a light incidence part A and is a part of the incidence pattern 310 that is optically coupled to the incidence pattern 310 through the light source 100, And the incident light is transmitted to the transverse side along the light guide plate 330 and is transmitted to the planar collimator pattern 320 on the opposite side of the light guide plate 330. The light guide plate 330 itself functions as a light incidence portion A, and simultaneously performs optical coupling and expansion.

The plane collimator pattern 320 corresponds to the waveguide light incident portion 350 formed on the first surface of the upper waveguide 1000 and transmits the incident incident light to the upper waveguide light incident portion 350. The reason for providing the waveguide light incidence part 350 is that the light transmitted through the light guide plate 330 and transmitted to the collimator pattern 320 is transmitted to the collimator pattern 320 in the vertical direction, To the waveguide 1000 in the transverse direction.

The light transmitted to the waveguide light entrance part 350 is transmitted along the core layer 120 of the waveguide 1000 and the light is emitted toward the surface of the upper exit pattern 370.

The shape of the outgoing light according to the shape of the outgoing pattern 370 can be changed in the form of divergent light, parallel light, and condensed light as described above.

Here, the incident light is transmitted along the light guide plate 330, and the emitted light is primarily transmitted along the waveguide 1000 and then emitted to the upper side of the outgoing pattern 150 on the upper side. The incident light and the outgoing light, 1 cladding layer 110, thereby preventing the interference between the incident light and the outgoing light, so that the shape of the outgoing light can be easily controlled.

In addition, when the optical system is used as a light source unit and applied to a display device by superimposing a path through which light of incident light and emitted light passes, the actual dead region includes incident patterns 310 on both sides and a plane collimator pattern 320 ) And the waveguide light incidence portion 350, the planar space outside the emission pattern 150 is reduced, and the dead region is significantly reduced.

Meanwhile, the optical system of the second embodiment of the present invention is thicker than the waveguide 1000 by about 10 times the thickness of the light guide plate 330. However, it is advantageous to reduce the planar dead area And a relatively thick light guide plate 330 is provided under the waveguide 1000 as a device, so that reliability and stabilization of the device when functioning as the light source unit can be achieved.

Meanwhile, in the second embodiment of the present invention, the incident pattern 310 attaches the HOE to the lower surface of the light guide plate with ease of attachment, converts the vertically incident light to the lateral direction, and transmits the light to the plane collimator pattern 320 The light can be expanded according to the length of the light source.

In some cases, the incident pattern 310 may be a grating pattern provided on a lower surface of the light guide plate 330. And, such a grating pattern may be a surface grating or a volume grating.

In addition, the plane collimator pattern 320 located on the opposite side of the incident pattern 310 may also be an HOE, which may have information on the HOE of the light. The planar collimator pattern 320 may also be a pattern of surface grating or volume grating. However, in this case, the planar collimator pattern 320 has a vertical transfer force and differs in that the light incident vertically, which is the function of the incident pattern 310 described above, is transversely transmitted. Therefore, The shape of the grating pattern may be different from the incident pattern 310. [

The optical path of the optical system according to the second embodiment of the present invention is as follows.

The light guide plate 330 transmits light entering the incident pattern 310 of the light incidence portion A to the planar collimator pattern 320 and transmits the light from the planar collimator pattern 320 to the waveguide light incidence portion 350 is coupled to the waveguide 1000. The coupled light is transmitted through the waveguide 1000 and is emitted to the upper side of the waveguide 1000 from the output pattern 370 of the light output portion.

Here, the first refractive index of the core layer 120 of the waveguide 1000 is higher than the second refractive index n2 of the lower first cladding layer 110. The first clad layer 110 is formed in contact with the light guide plate 330.

* Display device using the optical system of the first embodiment *

18 is a cross-sectional view showing the display device of the present invention in which the optical system of Fig. 2 is applied as a backlight unit.

18, when the optical system according to the first embodiment of the present invention is used as a backlight unit, the effective display area (active area) of the display panel 500 is made to correspond to the top of the emission pattern 150, Can be implemented.

Here, the display panel 500 is a light-receiving panel that receives light emitted from the lower optical system 2000 and receives a plurality of pixels arranged in a matrix on the effective display area, .

In this display device, the light-receiving area of the light-receiving display panel 500 corresponds to the area of the light output portion.

FIG. 19 is a perspective view showing the display device of the present invention in which the optical system of FIG. 2 is applied to a front light unit, and FIG. 20 is a sectional view of FIG.

As shown in FIG. 19, the optical system 2000 of FIG. 2 is inverted upside down so that the optical system of the first embodiment of the present invention is applied to the front light unit, And the display device is implemented.

In this case, the light transmitted through the waveguide 1000 is incident on the reflective display panel 600 through the lower emission pattern 150, which is then reflected by the reflective display panel 600 and then transmitted through the optical system 2000 The waveguide 1000 and the outgoing pattern 150 of the waveguide 1000.

For example, the reflective display panel 600 has a silicon wafer as a TFT substrate, and a counter substrate opposed thereto is a transparent substrate, and liquid crystal is filled therebetween. And that a plurality of pixels in a matrix are provided in the effective display region on the TFT substrate is the same as that of the liquid crystal display device.

In the TFT substrate, pixel electrodes are provided for each pixel, and a common electrode is provided on a counter substrate. Pixels are selectively operated according to the driving of the TFT provided for each pixel, When light enters, the degree of reflection per pixel is controlled to display the image.

* Display device using the optical system of the second embodiment *

21 is a cross-sectional view showing a display device of the present invention in which the optical system of Fig. 16 is applied as a backlight unit.

As shown in Fig. 21, the display device of the present invention in which the optical system according to the second embodiment of the present invention is applied as a backlight unit is configured such that a light receiving display panel (light receiving type image panel 500) such as a liquid crystal display panel, Is located on optical system 3000.

In this case, the optical system 3000 is configured such that the exit pattern 370 occupies almost the entire area of the waveguide 1000, and the incident pattern 310 and the edge area such as the plane collimator 320 and the waveguide light incident portion 350 The bezel area can be significantly reduced.

Since the optical system 3000 is formed in a flat plate shape except for the light source 100, it is advantageous to form the integrated display device by attaching the optical system 3000 and the light-receiving display panel 500 together.

FIG. 22 is a perspective view showing the display device of the present invention in which the optical system of FIG. 16 is applied as a front light unit, and FIG. 23 is a sectional view of FIG.

22 and 23 show an optical system according to the second embodiment of the present invention applied as a front light unit. The optical system 3000 of FIG. 16 is inverted upside down so that the exit surface is a reflective display panel Panel) 600 to implement a display device.

In this case, the light transmitted through the waveguide 1000 is incident on the reflective display panel 600 through the lower output pattern 370, which is then reflected by the reflective display panel 600 and then reflected by the optical system 3000 And the waveguide 1000. The waveguide 1000 and the output pattern 370 of the waveguide 1000 shown in Fig.

In this display device, the incident area and the reflection area of the reflective display panel 600 correspond to the area of the light output part.

For example, the reflection type display panel 600 uses a silicon wafer as a TFT substrate, and a detailed description thereof is as described above.

The above-described display device is suitable for implementing a privacy display device, a transparent display device, and an eyeglass 3D display.

In addition, it is easy to make the holographic display device slim and commercial as a 3D image display.

As described above, the optical systems of the first and second embodiments of the present invention can be applied to a backlight unit and a front light unit according to the light receiving type or reflection type of the image panel.

Further, in the optical system of the present invention, the total thickness of the optical system can be made to be equal to the total thickness of the waveguide or the waveguide and the light guide plate without a separate optical sheet, so that the light source unit can be configured as a super- It is possible to reduce the volume occupied by the light source unit, thereby making the display device slimmer.

Particularly, in the case of the first embodiment, the optical system can be made to have a waveguide thickness, and it is easy to implement the flexible display device with flexibility in addition to the slimming of the display device.

In the case of the second embodiment, most of the planar area of the optical system can be used as an outgoing light area, which can reduce the dead area and advantageous area of the display device. the area of the bezel can be reduced, and the operation of the module process is advantageous.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Will be apparent to those of ordinary skill in the art.

100: light source 110: first cladding layer
120: core layer 130: incidence pattern
140: clad pattern layer 150: emission pattern
160: second cladding layer
310: incidence pattern 320: plane collimator pattern
330: light guide plate 350: waveguide light incidence part
370: Exit pattern 500: Light receiving type display panel
600: reflective display panel 1000: waveguide
2000, 3000: Optical system

Claims (31)

Planar waveguide;
A light incident portion including an incident pattern on a part of a surface adjacent to a side portion of the waveguide and transmitting light having an expanded traveling width of incident light coming from a light source;
A planar collimator for transmitting the light expanded in the light incident portion to the waveguide so as to pass through the linear light; And
And a light output unit for outputting the linear light to the upper side of the waveguide. The method according to claim 1,
Wherein the light incidence portion, the plane collimator, and the light exit portion are divided into areas on the first surface of the waveguide. 3. The method of claim 2,
And a substrate on the second surface of the waveguide. 3. The method of claim 2,
Wherein the incident pattern is a holographic optical element (HOE) attached on the waveguide surface. 3. The method of claim 2,
Wherein the incident pattern is defined as a surface grating or a volume grating on the waveguide. 3. The method according to claim 1 or 2,
Wherein the light source is a laser. The method according to claim 1,
Wherein the light source comprises a red laser, a green laser, and a blue laser for introducing red light, green light, and blue light into different regions of the incident pattern. The method according to claim 1,
Wherein the waveguide includes a first cladding layer of a first refractive index n1 and a second cladding layer of a second refractive index n2 lower than the first refractive index. 9. The method of claim 8,
Wherein the planar collimator includes a clad pattern layer having a third refractive index (n3) larger than the second refractive index and smaller than the first refractive index on the waveguide. 10. The method of claim 9,
Wherein the planar collimator further includes a second clad layer of a fourth refractive index (n4) that fills the periphery of the clad pattern layer on the waveguide and is smaller than the first and third refractive indexes. 11. The method according to claim 9 or 10,
Wherein the planar collimator includes the clad pattern layer as a converging lens in a plane. 11. The method of claim 10,
Wherein the planar collimator includes the clad pattern layer as a diverging lens in a plane. The method according to claim 1,
Wherein the light output portion has an exit pattern having a surface grating and a volume grating that emits light coming from the planar collimator to one of the condensed light, the parallel light, and the divergent light on the upper side of the waveguide. 14. The method of claim 13,
Wherein the emission pattern is a curved grating on the waveguide to condense the linear light coming from the plane collimator onto the waveguide. 14. The method of claim 13,
Wherein the emission pattern is a linear grating on the waveguide to emit the linear light incoming from the plane collimator as parallel light on the upper side of the waveguide. 14. The method of claim 13,
Wherein the exit pattern is a curved grating on the waveguide, the straight-line light coming from the planar collimator diverging above the waveguide. 12. The method of claim 11,
Wherein the light output section has a linearly grilled outgoing pattern on the waveguide for converging the converged light coming from the plane collimator of the converging lens onto the wave guide. 13. The method of claim 12,
Wherein the light output section has a linearly-grating output pattern on the waveguide, the divergent light coming from the planar collimator diverging above the waveguide. 8. The method of claim 7,
Wherein the light output section has a different volume grating emission pattern for red light, green light, and blue light coming from the plane collimator, respectively. The method according to claim 1,
Wherein the waveguide has a light output portion on a first surface thereof,
And a light guide plate on the second surface of the waveguide. 21. The method of claim 20,
Wherein the light incidence portion and the plane collimator are located on opposite sides of the light guide plate. 22. The method of claim 21,
Further comprising a waveguide light incident portion on a first surface of the waveguide to overlap the planar collimator. 22. The method of claim 21,
Wherein the incident pattern is attached to a surface of a light guide plate contacting a second surface of the waveguide. 22. The method of claim 21,
Wherein the incident pattern is defined as surface grating or volume grating on the light guide plate. 22. The method of claim 21,
The light guide plate transmits light entering the light incidence portion to the plane collimator,
The light transmitted from the planar collimator to the waveguide light incidence portion is coupled,
The coupled light is transmitted through the waveguide,
And is emitted from the light output portion to the upper side of the waveguide. 26. The method of claim 25,
Wherein the waveguide includes a first cladding layer having a first refractive index and a first cladding layer having a second refractive index lower than the first refractive index,
And the first clad layer is in contact with the light guide plate. 27. The method of claim 26,
And the light coupled at the waveguide light incident portion is transmitted through the core layer of the waveguide. A light incident portion including a planar waveguide and an incident pattern positioned on a part of a surface adjacent to the side of the waveguide and transmitting light having an expanded traveling width of incident light coming from the light source; A backlight unit including a plane collimator for transmitting the expanded light to the waveguide so as to pass through the linear waveguide and a light output unit for outputting the linear light to the upper side of the waveguide; And
And a light receiving type image panel positioned on the backlight unit. 29. The method of claim 28,
And the light receiving region of the light receiving type image panel corresponds to the region of the light output section. A light incident portion including a planar waveguide and an incident pattern positioned on a part of a surface adjacent to the side of the waveguide and transmitting light having an expanded traveling width of incident light coming from the light source; A front collimator for transmitting the expanded light to the waveguide so as to pass through the straight wave, and a light output unit for outputting the linear light to the first surface of the waveguide; And
And a reflection type image panel adjacent to the light output part side of the front light unit for reflecting the light emitted from the light output part and transmitting the reflected light to the second surface of the wave guide. 31. The method of claim 30,
Wherein the incident area and the reflection area of the reflection type image panel correspond to the area of the light output part.

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