KR20160023732A - reflection plate for backlihgt unit - Google Patents

Abstract

An embodiment relates to a liquid crystal display for providing a transmission mode or a reflection mode. The liquid crystal display includes a liquid crystal display panel and a backlight unit. The backlight unit includes a light source, a light guide plate, and a reflection part. The reflection part is executed in one among the transmission mode and the reflection mode by electrophoresis or magnetophoresis.

Description

Reflector plate for backlight unit

The present invention relates to a reflective plate for a backlight unit and a liquid crystal display device including the same.

BACKGROUND ART [0002] Liquid crystal display devices are becoming increasingly widespread due to features such as light weight, thinness, and low power consumption driving. BACKGROUND ART Liquid crystal display devices are widely used as portable computers such as notebook PCs, office automation devices, audio / video devices, indoor and outdoor advertisement display devices, and the like. The liquid crystal display controls an electric field applied to the liquid crystal layer to modulate light incident from the backlight unit to display an image. BACKGROUND ART [0002] Liquid crystal display devices are changing in various forms according to the needs of consumers. For example, recently, a transparent liquid crystal display device has been developed which is transparently realized as a glass when an image is not displayed. Since a transparent liquid crystal display device is transparently realized when an image is not displayed, an object or a landscape hidden behind the transparent liquid crystal display device and positioned behind the transparent liquid crystal display device can be seen through the transparent liquid crystal display device. For example, the transparent liquid crystal display device can be realized by a window. In this case, the user can view the image through the transparent liquid crystal display device, and the transparent liquid crystal display device So that the user can appreciate the outside scenery. However, in the liquid crystal display device, since the optical sheets, the light guide plate, and the reflection sheet are sequentially stacked on the lower portion of the liquid crystal display panel, the liquid crystal display device is structured to be difficult to implement transparently. In order to implement a transparent liquid crystal display device, the back surface of the liquid crystal display panel must be designed to transmit light.

Prior Art Document: Korean Published Patent Application No. 2015-0002331

The present invention can be embodied as a reflective mode for a backlight unit for implementing a transparent liquid crystal display device in a simple viewing mode or a reflective mode.

In an aspect, a liquid crystal display device includes a liquid crystal display panel and a backlight unit, wherein the backlight unit includes a light source, a light guide plate, and a reflection unit, It is implemented in either one.

In one embodiment, the reflective portion includes a first transparent electrode and a second transparent electrode that are spaced apart from each other, the first transparent electrode and the second transparent electrode include a solvent, and the same charge The beating particles are dispersed, and one of the first transparent electrode and the second transparent electrode is divided into a main electrode and a local electrode so as to be electrically insulated.

In one embodiment, the local electrode is formed at a corner or side or bottom of the reflector.

In one embodiment, the perspective mode is implemented by assembling the particles only with the local electrode.

In one embodiment, the reflective portion includes a housing including a solvent and magnetic particles dispersed in the solvent, and a magnetic field generating portion for generating a magnetic field is disposed around the housing.

In one embodiment, a perspective mode or a reflection mode is implemented depending on the direction of the magnetic field generated by the magnetic field generating portion.

In one embodiment, when the direction of the magnetic field is generated in a direction perpendicular to the light guide plate, a perspective mode is implemented, and when the direction is parallel to the light guide plate, a reflection mode is implemented.

In one embodiment, the particles are coated with a light reflective material.

1 illustrates a transparent LCD display device according to an embodiment of the present invention.
2 shows a backlight unit according to an embodiment of the present invention.
3 shows a reflector according to an embodiment of the present invention.
4A shows a perspective mode state according to an embodiment of the present invention.
4B shows a reflective mode state according to an embodiment of the present invention.
6 shows a reflector according to an embodiment of the present invention.
6A illustrates a perspective mode state according to an embodiment of the present invention.
6B shows a reflective mode state according to an embodiment of the present invention.
7A to 7C show magnetic capsules according to an embodiment of the present invention.
8A and 8B show a magnetic capsule according to an embodiment of the present invention.

Hereinafter, exemplary embodiments will be described in more detail with reference to the accompanying drawings, wherein like reference numerals refer to like elements throughout. However, the present invention may be embodied in many different forms and should not be construed as limited to only illustrating the embodiments herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. For a complete understanding of aspects and features of the present invention, processes, elements and techniques not required by those skilled in the art may be discribed. Unless otherwise noted, like reference numerals refer to like elements throughout the description and the accompanying drawings, and so their description will not be repeated. In the drawings, the relative sizes of the elements, layers, and regions may be exaggerated for clarity.

Although the terms "first," "second," "third," etc. may be used herein to describe various elements, components, regions, layers and / or sections, , Regions, layers and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section described below may be referred to as a second element, component, region, layer or section without departing from the spirit and scope of the present invention.

Spatially relative terms, such as "directly under", "under", "under", "below", "above", "above", etc., May be used herein for ease of description in describing the relationship to other element (s) or feature (s) of the feature. It will be appreciated that these spatially relative terms should be interpreted to encompass different orientations of the device in use, or in operation, in addition to the orientation shown in the Figures. For example, if a device in the figures is inverted, the elements shown as being "under", "under", and "under" other elements or features may be Lt; / RTI > Thus, the exemplary terms "under" and "below" may include both upward and downward orientations. The device should be oriented accordingly (e.g., rotated 90 degrees or oriented in different orientations) and the spatially relative descriptors used herein should be interpreted accordingly.

When an element or layer is referred to as being "on," "connected to," or "connected to" another element or layer, the element or layer may be directly on, connected to, or connected directly to another element or layer Or intervening elements or layers may be present. Also, when an element or layer is said to be "between" two elements or layers, the element or layer may be the only element or layer between two elements or layers, or one or more intermediate intervening It will also be appreciated that elements or layers may also be present.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms of a noun are intended to also include the plural forms of the noun unless the context otherwise expressly indicates otherwise. The terms " comprises, "" comprising," " includes, "and " including ", when used in this specification, Elements, operations, elements, components, and / or groups of elements, while still specifying the presence of other elements, integers, steps, operations, elements, It will also be understood that it is not excluded. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. When preceded by a list of elements, expressions such as "at least one" decorate the entire elements of the list and do not decorate the individual elements of the list.

As used herein, the terms " substantially, "" about," and similar terms are used as terms of approximation and are not used as terms of approximation, It is intended to take into account the inherent deviations in the values. Further, the use of "may" in describing embodiments of the present invention refers to "one or more embodiments of the present invention ". As used herein, the terms "use," "use," and "used" are to be considered synonymous with the terms "utilizing", "utilizing" and "used", respectively. In addition, the term "exemplary" is intended to refer to either an example or an example.

1 illustrates a transparent LCD display device according to an embodiment of the present invention. The apparatus 100 includes a liquid crystal panel 101 and a backlight unit 102. The liquid crystal panel 101 is a transparent liquid crystal panel. The backlight unit 102 selectively implements a transparent mode and a reflective mode. This will be described later.

2 shows a backlight unit according to an embodiment of the present invention. The backlight unit 200 includes a light guide plate 201, a reflector 202, and a light source 203. In the backlight unit 200, the reflective portion 202 is changed to the light-transmitting state when the transparent LCD device 100 according to the present invention is implemented in a transparent or see-through mode, ) Is implemented in a display mode, it changes to a light reflecting state. As used herein, the perspective mode is a mode in which a viewer can view an object on the opposite side of the device through the transparent LCD device 100, and in the display mode, In which a specific image is displayed.

Electric field implementation method

3 shows a reflector according to an embodiment of the present invention. 3, the reflective portion 300 includes a first transparent electrode 330 and a second transparent electrode 340 facing the first transparent electrode 330. The second transparent electrode 340 includes a main electrode 340B and a second transparent electrode 340. [ And includes a local electrode 340A. Further, a solvent 320 exists between the first transparent electrode and the second transparent electrode, and particles 310 exist in the solvent. The particles 310 according to an embodiment of the present invention may be dispersed in the solvent 320 and exist in a solution state. According to one embodiment of the present invention, the particles 310 may have a positive charge or a negative charge. Accordingly, when an electric field is applied to the particle 310, the particle 310 can be moved (i.e., electrophoretically) due to the electric charge of the particle 310 and the electric attraction generated by the electric field. When the plurality of particles 310 have the same number of charges, the plurality of particles 310 do not contact each other due to the electric repulsive force (coulomb repulsion) due to the charges of the same sign, May be arranged.

More specifically, the particles 310 according to an embodiment of the present invention may include at least one of styrene, pyridine, pyrrole, aniline, pyrrolidone, acrylate, urethane, thiophene, carbazole, fluorene, vinylalcohol, ethylene glycol, Or a polymer material such as polystyrene (PS), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), or polyethylene terephthalate (PET). When polymer particles are used in this way, the particles can be coated with a reflective material. For example, it can be coated with silver or titanium. The particles of the present invention are charged with the same sign.

In addition, the particles 310 according to an embodiment of the present invention may be configured as a form coated with a substance having a charge on particles having no charge. For example, the surface is processed (or coated) by an organic compound having a surface treated (or coated) with an organic compound having a hydrocarbon group, a carboxylic acid group, an ester group or an acyl group Or coated with a compound containing a halogen (F, Cl, Br, I, etc.) element, an amine, a thiol or a phosphine Particles coated with a surface by a coordination compound, and particles having a charge by forming radicals on the surface.

In accordance with one embodiment of the present invention, solvent 320 is preferably dispersed in solvent 320 so that particles 310 are uniformly dispersed within solvent 320 to ensure colloidal stability. The difference in specific gravity between the particles 310 and the solvent 320 may be less than a predetermined value, the viscosity of the solvent 320 may be equal to or greater than a predetermined value, The electrokinetic potential (i.e., zeta potential) of the colloid solution composed of the solvent 320 and the solvent 320 may be higher than a predetermined value. The solvent of the present invention is a transparent solvent.

4A shows a perspective mode state according to an embodiment of the present invention. To this end, the charged particles 310 are collected toward the local electrode 340A among the second transparent electrodes 340. [ Although the local electrode 340A is shown largely for the sake of explanation in the drawings, it may be made very small in practice so that the liquid crystal display device is substantially viewed entirely. For example, in the case where the particles 310 are equally positively charged, a positive voltage is applied to the first transparent electrode, no voltage is applied to the main electrode of the second transparent electrode, A negative voltage is applied only to the electrode to move the positively charged particles toward the local electrode in an electric interlocking manner so that the transparent mode is realized through the transparent electrodes and the transparent solvent.

4B shows a display mode state according to an embodiment of the present invention. To this end, the particles 310 having the same charge as the charged particles or the reflective material itself are uniformly distributed toward the first transparent electrode, that is, the upper transparent electrode. Thus, due to the reflection characteristic of the particles, light is reflected from the light source 203 through the light guide plate 201 toward the LCD panel 101, and the LCD panel displays the corresponding image. In order to realize the display mode of the reflective portion, that is, to implement the reflective mode, for example, when all of the particles run out of negative charge, a positive voltage is applied to the first transparent electrode on the upper side, A negative voltage is applied to both the main electrode and the local electrode.

Although not shown, there is an insulating spacer between the main electrode and the local electrode.

Magnetic Field Implementation Method

5 shows a reflector according to an embodiment of the present invention. 5, the reflector 500 includes a housing 504 that includes a solvent 503, a magnetic particle 502 that is distributed in the solvent, and a plurality of magnetic particles 502 that are disposed around the housing 504, And a magnetism generating portion 501. Although the magnetic generation portion 501 is shown on the right and left sides 501A and 501B in this drawing, the present invention is not limited to this, and the arrangement of the magnetic generation portion 501 may vary depending on the shape of the housing 504. [ The magnetic particles 502 may include iron, cobalt, and nickel particles. In addition, the magnetic particles 502 are coated with a light reflecting material, for example, silver or titanium particles can be coated. The housing 504 may be any container capable of receiving a solvent.

Specifically, the particles may have magnetic properties such that they can be rotated or moved to receive magnetic force by magnetic fields. For example, magnetic particles such as nickel (Ni), iron (Fe), and cobalt (Co) . Also, according to one embodiment of the present invention, the particles may include a material that becomes magnetized as the magnetic field is applied, that is, magnetized. Particularly, according to an embodiment of the present invention, when an external magnetic field is applied to prevent a phenomenon of aggregation of particles having magnetism in the case where a magnetic field is not externally applied, magnetization occurs but an external magnetic field is not applied A superparamagnetic material which does not cause remnant magnetization can be used. Also, according to one embodiment of the present invention, in order to prevent the particles from being well dispersed in the solvent and agglomerate, the surface of the particles can be coated with the charge of the same sign, The particles may be coated with a material having a different specific gravity, or a solvent may be mixed with a material having a specific gravity different from that of the grains. In this embodiment, the solvent is a light-transmitting solvent.

6A illustrates a perspective mode state according to an embodiment of the present invention. To this end, the magnetic generating portions 501A and 501B make the direction of the magnetic field to be vertical, so that the magnetic particles 502 can pass the light substantially from the light guide plate 201 through the display region of the reflecting portion.

6B shows a reflective mode state according to an embodiment of the present invention. To this end, the magnetic generating portions 501A and 501B orient the direction of the magnetic field in the horizontal direction so that the magnetic particles 502 are reflected from the light guide plate 201 so that light is not substantially transmitted through the reflecting portion.

7 shows a magnetic capsule according to an embodiment of the present invention. In the embodiment of FIG. 5, a magnetic capsule may be used instead of magnetic particles. The capsule may include a plurality of magnetic particles 110, a solvent 120 and an encapsulating portion 130, and a plurality of magnetic particles 110 having magnetic properties may be contained in the solvent 120, As shown in FIG. 7A shows a case where a magnetic field is not applied, FIG. 7B shows a light transmission mode of the reflection part, and FIG. 7C shows a light reflection mode of the reflection part. The operation principle is similar to that described in Fig. The magnetic capsule of Fig. 7 may be fixedly disposed within the housing 504, for example.

8A illustrates another embodiment of a main electrode and a local electrode according to an embodiment of the present invention. In Fig. 8A, a local electrode is not provided at the lower end of the reflecting portion, but is partially provided at the side of the reflecting portion. 8B shows another embodiment of the main electrode and the local electrode according to an embodiment of the present invention. In Fig. 8B, a local electrode is partially provided at both the lower end and the side face of the reflector. As described above, there is an electrical insulator space between the main electrode and the local electrode.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- And various modifications and changes may be made thereto by those skilled in the art to which the present invention pertains. Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (9)

A liquid crystal display device comprising:
A liquid crystal display panel and a backlight unit,
The backlight unit includes a light source, a light guide plate, and a reflector,
Wherein the reflective portion is implemented in either a transmissive mode or a reflective mode by electrophoresis or magnetophoresis of particles,
Liquid crystal display device. The method according to claim 1,
Wherein the reflective portion includes a first transparent electrode and a second transparent electrode facing each other and facing each other,
A solvent is included between the first transparent electrode and the second transparent electrode,
Particles having the same charge are dispersed in the solvent,
Wherein one of the first transparent electrode and the second transparent electrode is electrically insulated by a main electrode and a local electrode,
Liquid crystal display device. 3. The method of claim 2,
The local electrode may be formed at a corner, a side surface,
Liquid crystal display device. 3. The method of claim 2,
Wherein the perspective mode is implemented by assembling the particles only with the local electrode.
Liquid crystal display device. The method according to claim 1,
Wherein the reflective portion comprises a housing including a solvent and magnetic particles dispersed in the solvent,
Wherein a magnetic field generating portion for generating a magnetic field is disposed around the housing,
Liquid crystal display device. 6. The method of claim 5,
Wherein a perspective mode or a reflection mode is implemented according to a direction of a magnetic field generated by the magnetic field generating unit,
Liquid crystal display device. The method according to claim 6,
Wherein when a direction of the magnetic field is generated in a direction perpendicular to the light guide plate, a perspective mode is implemented, and when a direction parallel to the light guide plate is generated,
Liquid crystal display device. 9. The method according to any one of claims 1 to 8,
The particles may be coated with a light reflecting material,
Liquid crystal display device. The method according to claim 1,
Wherein the reflective portion comprises a housing containing a plurality of magnetic capsules, the magnetic capsules comprising an encapsulant surrounding the solution and magnetic particles distributed in the solution,
Wherein a magnetic field generating portion for generating a magnetic field is disposed around the housing,
Liquid crystal display device.

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