KR20180007041A - Reflective liquid crystal display device - Google Patents

Abstract

The present invention relates to a reflective liquid crystal display device which comprises: a display panel; a light source unit positioned on the same plane with the display panel; a reflection member positioned at the height different from those of the display panel and the light source unit, and reflecting light emitted by the light source unit to emit the light toward the display panel; a light quantity detection sensor for detecting an external light quantity to output light quantity data; and a light source control unit for controlling the intensity of the light emitted by the light source unit by receiving the light quantity data. Therefore, the reflective liquid crystal display device has improved visibility.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a reflective liquid crystal display

The present invention relates to a reflection type liquid crystal display device.

2. Description of the Related Art Recently, a display device for displaying an image using a liquid crystal display panel, a plasma display panel, an electroluminescence display panel, and an organic light emitting display panel has attracted attention as a display device.

A liquid crystal display device includes a liquid crystal display panel, and displays an image by adjusting the liquid crystal array to adjust the transmittance of light. Such a liquid crystal display device is a display device which can not generate light by itself. Accordingly, the transmissive liquid crystal display device includes a backlight assembly that provides light to the liquid crystal display panel. However, the backlight assembly consumes a lot of power.

BACKGROUND ART A display device capable of being driven with a low power consumption is a reflection type liquid crystal display device. The reflection type liquid crystal display device displays a screen by adjusting the transmittance of light by reflecting natural light or artificial light outside. However, in the reflection type liquid crystal display device, when the amount of external light is small, the amount of reflected light is small and the visibility is reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a reflection type liquid crystal display device in which visibility is improved by driving a light source to increase external light quantity.

According to an aspect of the present invention, there is provided a reflection type liquid crystal display device including: a display panel; A light source positioned on the same plane as the display panel; A reflecting member which is located at a different height from the display panel and the light source unit and reflects the light emitted from the light source unit and outputs the reflected light toward the display panel; A light amount detecting sensor for detecting an external light amount and outputting light amount data, and a light source control unit for receiving the light amount data and controlling intensity of light emitted from the light source unit.

The reflecting member may include a reflecting surface that reflects the light emitted from the light source portion.

The reflective surface may have an angle of less than 45 degrees with an imaginary plane extending from the display panel.

The reflecting surface may have a curvature.

And a partition wall disposed between the display panel and the light source and having a height greater than that of the light source.

And a light guide plate positioned on the same plane as the reflective member.

And may further include irregularities disposed on the reflecting surface.

The display panel may further include a reflective layer.

The reflective layer may be made of metal.

 A bottom case for housing the display panel and the light source unit, and a top case for being fastened to the bottom case.

The light amount detection sensor may be disposed in the top case.

The reflection type liquid crystal display device according to the present invention provides the following effects.

First, it is possible to increase the amount of light incident on the reflective display panel by driving the light source part. Thereby, a reflection type liquid crystal display device with improved visibility even when the external light amount is small is provided.

Secondly, a separate member is not disposed on the reflective display panel, so that the transmittance can be improved.

Third, the light shield can be minimized by disposing a barrier between the display panel and the light source on the same plane.

Fourth, light leakage can be minimized by disposing a light guide plate on the display panel.

1 is an exploded perspective view of a reflection type liquid crystal display device according to an embodiment of the present invention.
2 is a plan view of a reflection type liquid crystal display device according to an embodiment of the present invention.
FIG. 3A is a sectional view taken along line I-I 'of FIG. 1; FIG.
FIG. 3B is an enlarged view of part A of FIG. 3A.
4 is a view for explaining another shape of the reflecting member.
5 is a view for explaining the unevenness of the reflecting member.
6 is a view for explaining a driving method of a reflection type liquid crystal display device according to an embodiment of the present invention.
7A and 7B are views for explaining driving of a reflective liquid crystal display device according to an embodiment of the present invention.
8A is a cross-sectional view of a reflection type liquid crystal display device according to another embodiment of the present invention corresponding to I-I 'of FIG.
Fig. 8B is an enlarged view of part B of Fig. 8A.
9A is a sectional view of a reflection type liquid crystal display device according to another embodiment of the present invention, which corresponds to I-I 'of FIG.
Fig. 9B is an enlarged view of the portion C in Fig. 9A.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the scope of the present invention is not limited to the embodiments and drawings described below.

The terminologies used herein are terms used to describe the embodiments of the present invention, which should be interpreted according to the user, the intention of the operator, or the practice of the field to which the present invention belongs. The definition of a term should be based on the contents throughout the specification.

In the drawings, in order to facilitate understanding of the present invention, each component and its shape may be briefly drawn or exaggerated, and components in an actual product may be omitted without being represented. Accordingly, the drawings are to be construed as illustrative of the invention. Components having the same or similar functions in the drawings are denoted by the same reference numerals.

The terms spatially relative, "below", "beneath", "lower", "above", "upper", " May be used to easily describe one element or elements and other elements or elements as shown in FIG. Spatially relative terms should be understood to include, in addition to the orientation shown in the drawings, terms that include different orientations of the device during use or operation. For example, when inverting an element shown in the figures, an element described as being "below" or "beneath" another element may be placed "above" another element have. Thus, the exemplary term "below" can include both downward and upward directions. The elements can also be arranged in different directions, so that spatially relative terms can be interpreted differently depending on the placement direction.

The terms used herein are not intended to limit the scope of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprises " and / or "comprising" when used in this specification is taken to specify the presence or absence of one or more other components, steps, operations and / Or additions.

It will be understood that when an element is described as being "connected" to another element, it is understood that not only is there a direct contact between the element and another element, It is meant to include.

It will also be understood that where a layer or component is described as being on or in the "top" of another layer or component, it is understood that not only is the layer or component disposed in direct contact with the other layer or component , And a case where a third layer is disposed interposed therebetween.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

FIG. 1 is an exploded perspective view of a reflection type liquid crystal display device according to an embodiment of the present invention, and FIG. 2 is a plan view of a reflection type liquid crystal display device according to an embodiment of the present invention. FIG. 3A is a cross-sectional view taken along line I-I 'of FIG. 1, and FIG. 3B is an enlarged view of a portion A of FIG. 3A. 4 is a view for explaining another shape of the reflecting member. 5 is a view for explaining the unevenness of the reflecting member.

1 to 5, a reflection type liquid crystal display device according to an embodiment of the present invention will be described.

1 to 3A, the reflection type liquid crystal display of the present invention includes a display panel 100, a light source unit 200, a top case 310, a bottom case 320, a light amount detection sensor 400, A light source control unit (not shown), and a reflective member 610.

The display panel 100 displays an image. The display panel 100 includes a lower panel 101, an upper panel 102 positioned opposite the lower panel 101, a liquid crystal layer (not shown) positioned between the lower panel 101 and the upper panel 102, And a driving circuit section.

Although not shown, one pixel may be defined by an upper panel 102, a lower panel 101, and a liquid crystal layer (not shown). The pixel is located on the display portion DA of the display panel 100. [

The display panel 100 is a reflective display panel, and includes a reflective layer (not shown) inside. The external light emitted to the display panel 100 is reflected by the reflective layer to the front surface of the display panel 100 to display an image. The reflective layer can be made of metal. For example, the reflective layer may be made of a reflective film containing aluminum (Ag) or silver (Ag).

The driving circuit portion is located in the non-display portion (NDA) of the display panel (100). The drive circuit portion includes a driver 141 and a printed circuit board 142 that are constituted by a drive integrated circuit 141a and a carrier 141b. The driving integrated circuit 141a generates signals for driving the display panel 100 in accordance with a control signal provided from a timing controller (not shown) or a power supply unit (not shown), and supplies the signals to a plurality of gate lines and data lines Respectively. Each driving integrated circuit 141a is mounted on the carrier 141b. The carrier 141b is connected between the printed circuit board 168 and the display panel 100. The timing controller and the power supply unit described above may be disposed on the printed circuit board 142. The carrier 141b may include input wires for transmitting various signals from the timing controller and the power supply unit to the data driving integrated circuit 141a And output wirings for transmitting the signals output from the driving integrated circuit 141a to the corresponding lines.

The light source 200 is located on the same plane as the display panel 100. For example, the light source 200 may be disposed on one side, both sides, or all four sides of the display panel 100, and may be disposed on at least one of the corners of the display panel 100.

The light source unit 200 generates light. The light generated by the light source unit 200 is reflected by the reflection member 610 to be described later and is output to the display panel 100. The light source unit 200 may include a light source circuit board 210 and at least one light source 220. One side of the light source circuit board 210 is divided into at least one mounting area and a wiring area (not shown). When the number of the light sources 220 is two or more, one light source 220 is installed in each mounting region, and a plurality of wirings are installed in the wiring region to transmit driving power to the wiring region by the light sources 220. The above-described driving power is generated in an external power supply (not shown), and then supplied to a plurality of wires described above through a separate connector (not shown).

For example, as shown in FIG. 1, nine light sources 220 are disposed on both sides of the display panel 100, but the present invention is not limited thereto. (220) may be different. In addition, the light source 220 may have a rectangular shape. However, the present invention is not limited thereto, and the light source 220 may be a rod-like or hemispherical shape extending along the light source circuit board 210. The light source 220 may be a light emitting diode. For example, the light source 220 may be one of a red light emitting diode, a green light emitting diode, and a blue light emitting diode. Alternatively, the light source 220 may be a light source emitting an ultraviolet ray or a near ultraviolet ray.

The top case 310 has a rectangular frame shape with an open central portion. The top case 310 is placed on the display panel 100. The display portion DA of the display panel 100 is exposed through the open portion of the top case 310. [ The top case 310 surrounds the edge of the display panel 100. The top case 310 includes a front cover 311 covering the edge of the display panel 100 and a side cover 312 covering the side portion 322 of the bottom case 320 .

On the other hand, a coupling groove can be located in the side cover 312, and the top case 310 can be fixed to the bottom case 320 by the coupling groove. Further, any one of the side covers 312 may have an opening. Although not shown, the driver circuit portion may be exposed to the outside of the top case 310 through the opening of the side cover 312.

Although not shown, the front cover 311 of the top case 310 may have a longer length than the reflective member 610 described later. The front cover 311 having a longer length than the reflecting member 610 is a portion of the light reflected by the reflecting member 610 and not directed to the display panel 100 to be emitted toward the front face of the display panel 100 Can be prevented. Thus, the reflection type liquid crystal display device according to an embodiment of the present invention can minimize light leakage. The front cover 311 of the top case 310 may be formed of a transparent material such as a glass or a metal having a refractive index higher than that of the reflective member 610 according to the size of the display panel 100, the intensity of the light source 200, It may have a shorter length.

The bottom case 320 includes a receiving space therein. A display panel 100 and a light source unit 200 to be described later are arranged in this storage space. In order to secure this accommodating space, the bottom case 320 may include a base portion 321 and a plurality of side portions 322. For example, the base portion 321 may have a rectangular shape, and each of the aforementioned side portions 322 protrudes from each edge of the base portion 321 to have a predetermined height. The edges of the adjacent side portions 322 are connected to each other. The above-mentioned storage space is defined as a space surrounded by the side portions 322 and the base portion 321. [ On the other hand, a locking protrusion is formed on the outer side of the side portions 322 facing each other, and the top case 310 is fixed to the bottom case 320 by the locking protrusion. The latching jaw may be bent so that a part of the side portion 322 protrudes toward the top case 310.

The structure of the top case 310 and the bottom case 320 is not limited to this, and a form capable of housing the display panel 100 and the light source unit 200 is sufficient.

The light amount detection sensor 400 may be disposed in the top case 310 described above. For example, as shown in FIGS. 1 and 2, the light amount detection sensor 400 may be disposed on the front cover 311 of the top case 310. Specifically, the front cover 311 of the top case 310 may have at least one groove, and the light amount detecting sensor 400 may be positioned in the groove disposed in the front cover 311 of the top case 310 can do. The light amount detection sensor 400 detects the external light amount and outputs light amount data. At this time, the external light amount is the sum of the amount of light emitted by the light source part 200 and the amount of light around the reflection type liquid crystal display device.

The light source control unit (not shown) receives light amount data and controls the intensity of light emitted from the light source unit 200.

The light amount detection sensor 400 and the light source control unit 500 will be described later in detail with reference to FIG. 6 and FIG.

The reflective member 610 is located at a different height from the display panel 100 and the light source 200. For example, as shown in FIG. 3A, the reflective member 610 may be positioned below the front cover 311 of the top case 310 disposed apart from the display panel 100. The reflective member 610 may be attached and fixed to the lower portion of the front cover 311 of the top case 310 by an adhesive member (not shown). However, the present invention is not limited thereto, and the reflective member 610 can be attached and fixed to the top case 310 by fastening members such as bolts and nuts.

The reflection member 610 reflects the light emitted from the light source unit 200 and reflects the light toward the display panel 100. The reflecting member 610 may include a reflecting surface 611 that reflects the light emitted from the light source 200.

Referring to FIG. 3B, the light L1 emitted from the light source 220 and incident on the reflection surface 611 may have a normal line Lv perpendicular to the reflection surface 611 and an incident angle of? 111. The light L2 reflected by the reflective surface 611 may have an angle of reflection of? 12 with the normal Lv of the reflective surface 611. [ At this time, the incident angle? 11 of the reflection surface 611 and the reflection angle? 12 of the reflection surface 611 are substantially the same.

An imaginary line Lr extending from the reflective surface 611 and an imaginary line Lp extending from the display panel 100 form an angle of? 1. Accordingly, the light emitted from the light source unit 200 can be reflected by the reflecting surface 611 of the reflecting member 610 and incident on the display panel 100. Specifically,? 1 can have an angle of 45 degrees or less. Accordingly, the amount of light that is not incident on the display panel 100 among the light reflected by the reflective member 610 is reduced, thereby minimizing light leakage.

As shown in FIG. 4, the reflecting member 610 may further include concave and convex portions 612 disposed on the reflecting surface 611. The light supplied from the light source unit 200 is irregularly reflected by the irregularities 612 disposed on the reflection surface 611 and can be incident uniformly on the display panel 100. [ The irregularities 612 may be hemispherical. The concavities and convexities 612 may be in the form of a cone, a polygonal pyramid, or the like, and a shape capable of irregularly reflecting the light emitted from the light source unit 200 is sufficient.

The reflecting surface 611 may have a curvature. Specifically, as shown in Fig. 5, the reflecting surface 611 may have a concave shape. However, the present invention is not limited thereto, and the reflecting surface 611 may have a convex shape. Accordingly, the reflective member 610 reflects the light emitted from the light source 200 and emits the light toward the display panel 100. At this time, the amount of light output to the display panel 100 can be increased in accordance with the curvature of the reflective surface 611. [ In other words, the amount of light that is not incident on the display panel 100 among the light reflected by the reflective member 610 is reduced, minimizing light leakage, and improving the efficiency of the reflective liquid crystal display device.

FIG. 6 is a view for explaining a method of driving a reflective liquid crystal display device according to an embodiment of the present invention, and FIGS. 7a to 7b illustrate driving of a reflective liquid crystal display device according to an embodiment of the present invention FIG.

The reflection type liquid crystal display device according to an embodiment of the present invention can increase the amount of external light by driving the light source unit 200 when the amount of ambient light is small and the visibility is reduced. Accordingly, the reflection type liquid crystal display device according to an embodiment of the present invention can improve visibility even when the amount of ambient light is small. This will be described later in detail with reference to FIG. 6 and FIG.

The light amount detection sensor 400 detects the external light amount (S1). Since the light emitted from the light source unit 200 is incident on the display panel 100 as well as the light around the reflection type liquid crystal display device, the light amount detection sensor 400 detects the amount of light around the reflection type liquid crystal display device, Which is the sum of the amount of light emitted from the light source. The light amount detection sensor 400 outputs the detected light amount as light amount data.

The light source control unit (not shown) receives the light amount data and analyzes the light amount (S2). The light source control unit adjusts the intensity of the light source according to the analyzed amount of light (S3), thereby displaying an image with improved visibility (S4). For example, as shown in FIG. 7A, when the external light amount is equal to or greater than a predetermined light amount, the intensity of light emitted from the light source unit 200 may be reduced by turning off the light source 220. On the other hand, as shown in FIG. 7B, when the external light amount is less than a predetermined light amount, the intensity of light emitted from the light source unit 200 can be increased by turning on the light source 220. In particular, when the visibility is decreased due to a small amount of ambient light, the light source unit 200 may be driven to increase the amount of external light, thereby improving visibility. Accordingly, the reflection type liquid crystal display device according to an embodiment of the present invention can improve the visibility regardless of the amount of ambient light.

8A is a cross-sectional view of a reflection type liquid crystal display device according to another embodiment of the present invention corresponding to I-I 'of FIG. 1, and FIG. 8B is an enlarged view of a portion B of FIG. 8A.

Another embodiment of the present invention will be described in detail with reference to Figs. 8A to 8B. The description related to the reflection type liquid crystal display device according to another embodiment of the present invention and the description related to the reflection type liquid crystal display device according to the embodiment of the present invention will be omitted.

The reflection type liquid crystal display device according to another embodiment of the present invention may further include a partition 620 disposed between the display panel 100 and the light source 200 positioned on the same plane. Light emitted from the light source unit 200 may be generated by light not incident on the reflection member 610. The barrier rib 620 absorbs and reflects light not incident on the reflective member 610 out of the light emitted from the light source 200 to prevent light leakage. The barrier rib 620 may have a height greater than that of the light source 200. Accordingly, the light blocking effect by the partition 620 can be improved.

9A is a sectional view of a reflection type liquid crystal display device according to another embodiment of the present invention corresponding to I-I 'of FIG. 1, and FIG. 9B is an enlarged view of a portion C of FIG. 9A.

Another embodiment of the present invention will be described in detail with reference to Figs. 9A to 9B. The description related to the reflection type liquid crystal display device according to another embodiment of the present invention and the description related to the reflection type liquid crystal display device according to one embodiment of the present invention and the other embodiment will be omitted.

The reflection type liquid crystal display device according to another embodiment of the present invention may further include a light guide plate 630 positioned on the same plane as the reflection member 610. 9B, the light guide plate 630 may be disposed between the top case 310 on the display panel 100 and the reflective member 610 disposed on both sides of the bottom case 320, respectively. have.

Although not shown, the reflection type liquid crystal display device according to another embodiment of the present invention may further include a mold frame for fixing the light guide plate 630.

The light guide plate 630 includes a front surface, a rear surface and a side surface facing each other, and a surface facing the display panel 100 is called a rear surface, a surface facing the rear surface is called a front surface, and a surface connecting the front surface and the rear surface is defined as a side surface.

The light emitted from the light source unit 200 may be reflected by the reflection member 610 and then incident through at least a part of the side surface and the rear surface of the light guide plate 630. The light incident on the light guide plate 630 can propagate in the light guide plate 630.

Although not shown, the light guide plate 630 may have a wedge-shaped groove for changing the direction of light propagated inside the light guide plate 630 on the entire surface of the light guide plate 630. The wedge-shaped grooves may be arranged in parallel to each other and may have a prism surface having a prism shape. The wedge-shaped groove including the prism surface can reflect light propagating inside the light guide plate 630 and emit light toward the display panel 100. Accordingly, the reflection type liquid crystal display device according to the present invention can receive light uniformly by the light guide plate 630, and can have a uniform luminance. In addition, the light guide plate 630 can prevent light leakage caused by light not incident on the reflecting member 610. [

Although the light guide plate 630 has been described as a plate for convenience of explanation, it may be formed in the form of a sheet or a film for slimming down the reflection type liquid crystal display device. That is, the light guide plate 630 is described as a concept including both a plate and a film for guiding light.

The light guide plate 630 may be made of a light-transmitting material such as acrylic resin such as PMMA (PolyMethylMethacrylate) or polycarbonate (PC) to efficiently guide light.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. Will be clear to those who have knowledge of.

100: display panel 200:
310: top case 320: bottom case
400: light amount detection sensor 610: reflection member
611: Reflecting surface 620:
630: light guide plate

Claims (11)

Display panel;
A light source positioned coplanar with the display panel;
A reflective member positioned at a different height from the display panel and the light source unit and reflecting the light emitted from the light source unit and outputting the reflected light toward the display panel;
A light quantity detecting sensor for detecting an external light quantity and outputting light quantity data;
And a light source control unit that receives the light amount data and controls intensity of light emitted from the light source unit. The reflective liquid crystal display of claim 1, wherein the reflective member includes a reflective surface that reflects the light emitted from the light source. The reflection type liquid crystal display of claim 2, wherein the reflective surface has an angle of less than 45 degrees with an imaginary plane extending from the display panel. The reflective liquid crystal display of claim 2, wherein the reflective surface has a curvature. The reflective liquid crystal display of claim 1, further comprising a barrier disposed between the display panel and the light source and having a height greater than that of the light source. The reflective liquid crystal display of claim 1, further comprising a light guide plate positioned on the same plane as the reflective member. The reflective liquid crystal display of claim 2, further comprising concavo-convexes arranged on the reflective surface. The reflective liquid crystal display of claim 1, wherein the display panel further comprises a reflective layer. The reflective liquid crystal display of claim 8, wherein the reflective layer is made of a metal. The reflective liquid crystal display of claim 1, further comprising: a bottom case for accommodating the display panel and the light source; and a top case coupled to the bottom case. The reflective liquid crystal display of claim 10, wherein the light amount detection sensor is disposed in the top case.

Images