JP3243169U - backlight module and display - Google Patents

Abstract

The present invention relates to a backlight module and a display device. The backlight module comprises a light guide plate, a lower light source adjacent to the side edges of the light guide plate, and a plurality of condensing lights disposed above and adjacent to the light guide plate toward the light guide plate. A light collection element provided with a structure and an upper light source provided adjacent to the light input side of the light collection element. The backlight module and the display device realize a narrow viewing angle anti-peeping mode by turning on only the lower light source, or a wide viewing angle shared mode by turning on the lower light source and the upper light source at the same time. come true. [Selection drawing] Fig. 2

Description

TECHNICAL FIELD The present invention relates to the technical field of displays, and more particularly to a backlight module and a display device with switchable viewing angles.

2. Description of the Related Art With the progress of science and technology, electronic devices equipped with liquid crystal displays have become essential items in modern people's lives. However, in different occasions, people have different demands on the viewing angle of the display device. For example, if multiple people all need to be able to see the display screen content at different angles in order to share information with people, then a wide viewing angle, ie sharing mode, is required for the display device. When handling personal material and only the user himself/herself can see the contents of the display screen and need to protect the privacy, the display product is required to have an anti-peeping mode.

In order to solve the above problem, as shown in FIG. 1, from top to bottom, a display panel 11, a first light guide plate 12, a light shielding sheet 13, an inverted prism sheet 14, a second light guide plate 15 and a reflective A representation of a dual light source backlight module comprising a sheet 16 and a first light source 17 and a second light source 18 placed adjacent to the light input sides of a first light guide plate 12 and a second light guide plate 15 respectively. Equipment is provided.

In the peep prevention mode, the display device 10 turns on only the second light source 18 below, and the light emitted from the second light source 18 is guided by the second light guide plate 15 and then passes through the inverted prism Light is condensed and light diameter is restricted by the sheet 14 and the light shielding sheet 13, and the light emitted from the display panel 11 has a narrow light emission angle. have. In the shared mode, the display device 10 turns on the first light source 17 and the second light source 18 at the same time, and in addition to the light beam after being guided by the second light guide plate 15, the light from the first light source 17 Including light rays emitted and guided through the first light guide plate 12, at this time, more light rays reach the display panel 11, and the light emission angle is wide, so that the display screen content can be viewed at different angles. and the display device 10 has a wide viewing angle function.

However, the above viewing angle switching technology adopts two light guide plates, and actually uses two sets of backlight modules and shading technology to achieve the purpose of viewing angle switching. or using an optical film, which increases both the overall thickness and cost of the backlight module.

The purpose of the present invention is to provide a backlight module technology that integrates the light guide plate and the light concentrating element, which can achieve the function of switching the viewing angle with only one set of backlight modules, and the overall thickness of the backlight module is thickness can be reduced and costs can be reduced.

To achieve the above objects, the present invention includes a light guide plate, a lower light source adjacent to the side edges of the light guide plate, a light incident side and a bottom surface, and adjacent to the upper side of the light guide plate. a backlight module, comprising: a light condensing element provided with a plurality of light condensing structures facing the light guide plate on the bottom surface; and an upper light source provided adjacent to the light incident side of the light condensing element. I will provide a.

In a preferred form, the condensing element includes a first side and a second side connected to each other, the first side being parallel to the first direction and the second side being parallel to the first direction. a side parallel to a second direction and the first direction perpendicular to the second direction; the lower light source comprising a plurality of light emitting diodes; The light emitting diodes are arranged along the first direction on the side edge of the light guide plate.

As a preferred form, the light incident side of the condensing element is located on the first side, the upper light source includes a plurality of light emitting diodes, and the plurality of light emitting diodes of the upper light source are arranged on the first side. arranged along the first side of the condensing element along one direction. Or, the light incident side of the condensing element is located at the second side, the upper light source comprises a plurality of light emitting diodes, and the plurality of light emitting diodes of the upper light source are aligned in the second direction. are arranged along the second side of the condensing element.

As a preferred form, each of the condensing structures is a striped fine structure whose extending direction is parallel to the first direction and perpendicular to the second direction.

As a preferred form, the condensing element is an inverted prism sheet, and each of the condensing structures has a prism angle with a tip facing the light guide plate.

As a preferred form, the bottom surface of the light guide plate is a reflective surface, and a plurality of light guide structures are formed on the reflective surface. Each light guide structure has a light-receiving surface and a non-light-receiving surface connected to each other, the light-receiving surface facing the light traveling direction of the lower light source, and a first light-receiving surface between the light-receiving surface and the reflective surface. An included angle is formed and a second included angle is formed between the non-light receiving surface and the reflective surface, the first included angle being acute and less than the second included angle.

In a preferred form, uniformly distributed diffusing particles were provided within the concentrating element. Alternatively, a top surface of the condensing element facing the bottom surface has a diffusing particle layer.

Preferably, the backlight module further includes a reflective sheet provided below the light guide plate.

Another object of the present invention is to provide a display device that utilizes the backlight module technology of integrating the light guide plate and the steering panel, which can achieve the function of switching the viewing angle with only one set of backlight modules. Therefore, the overall thickness of the display device can be reduced, and the cost can be reduced.

To achieve the above objectives, the present invention provides a display device, which includes a backlight module and a display panel provided above and adjacent to the backlight module.

Compared with the prior art, the present invention has the following features. In the backlight module of the present invention, the light sources are respectively installed on the light guide plate and the light collecting element above it, so that when the lower light source is turned on and the upper light source is turned off, the light emitted from the light guide plate is The light rays are folded back and concentrated by the condensing element and emitted in the normal direction, so as to realize the narrow viewing angle anti-peeping mode of the backlight module, and when both the lower light source and the upper light source are turned on, the light is emitted from the light guide plate. Not only is the emitted light beam folded back by the condensing element to be emitted in the normal direction, but also the light beam that has passed through only the light condensing element without passing through the light guide plate is folded back, dispersed and emitted to form a backlight. Realize the wide viewing angle sharing mode of the module. The number of optical plates or optical films required for the backlight module of the present invention is small, so that the overall thickness of the backlight module can be reduced and the cost can be reduced.

1 is a schematic side view of a display device of a conventional viewing angle switching backlight module; FIG. FIG. 3 is a schematic diagram of a backlight module according to an embodiment of the present application; FIG. 4 is a schematic diagram of a backlight module according to another embodiment of the present application; FIG. 4 is a schematic side view of a display device to which the embodiment shown in FIG. 3 is applied; 1 is a schematic diagram of a first embodiment of a concentrating element in an example of the present application; FIG. FIG. 4 is a schematic diagram of a second embodiment of a concentrating element in the examples of the present application; FIG. 2B is a first schematic diagram of a ray path in an embodiment of the present application; FIG. 2B is a second schematic diagram of a ray path in an embodiment of the present application; 4 is a viewing angle-luminance graph of the display device to which the embodiment shown in FIG. 3 is applied; 3 is a schematic side view of a display device to which the embodiment shown in FIG. 2 is applied; FIG. 3 is a viewing angle-luminance graph of the display device to which the embodiment shown in FIG. 2 is applied;

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The drawings are mainly simplified schematic diagrams, in order to explain the basic structure of the present invention only in schematic form, only the parts related to the present invention are shown in the drawings, and the displayed parts are not implemented. It is not drawn in numbers, shapes, dimensional ratios, etc., and the actual implementation specification dimensions are all optional designs, and the layout form of the parts may become more complicated.

The following description of each embodiment refers to the drawings to illustrate specific embodiments in which the invention can be practiced. Directional terms such as "top", "bottom", "front", "back", etc. referred to in the present invention refer only to directions in the drawings. Accordingly, the directional terminology used is used to describe and understand the application and is not intended to be limiting of the application. Also, in the specification, unless expressly stated to the contrary, the term "comprising" is understood to mean including an element but does not exclude any other element.

Please refer to FIGS. 2 and 3, which are schematic diagrams of a backlight module according to an embodiment of the present invention. The backlight module 100 includes a light guide plate 200, a lower light source 400 provided adjacent to a side edge 210 of the light guide plate 200, and a light entrance side 311 (as shown in FIG. 2) or a light entrance side 321 (FIG. 3). ) and a bottom surface 340, provided above and adjacent to the light guide plate 200, the bottom surface 340 being provided with a plurality of light collection structures 350 directed toward the light guide plate 200; and an upper light source 500 located adjacent to the light input side 311 (as shown in FIG. 2) or the light input side 321 (as shown in FIG. 3) of 300 .

In the backlight module 100 of the present application, the light sources 400 and 500 are respectively installed on the light guide plate 200 and the light collecting element 300 thereabove, so that when the lower light source 400 is turned on and the upper light source 500 is turned off, the light can be guided. Light emitted through the light plate 200 is folded and concentrated by the light collecting element 300 so as to emit light in a normal direction. When all the upper light sources 500 are turned on, the light emitted from the lower light sources 400 through the light guide plate 200 is reflected by the light collecting element 300 and emitted in the normal direction, and the light from the upper light sources 500 is emitted. The light is folded back and dispersed by the condensing element 300 to realize a wide viewing angle sharing mode of the backlight module 100 . Compared with the prior art, the backlight module 100 of the present application requires fewer optical plates or optical films, the thickness of the whole structure can be reduced, and the cost can be reduced.

In practical applications, the backlight module 100 further includes a reflective sheet 600 provided below the light guide plate 200 .

Also, referring to FIG. 4, FIG. 4 is a schematic side view of the display device to which the embodiment shown in FIG. 3 is applied. When the backlight module 100 is applied to the display device 1000 , the display device 1000 includes at least the display panel 700 and the backlight module 100 , and the display panel 700 is provided above and adjacent to the backlight module 100 .

In practical applications, the concentrating element 300 includes a first side 310 and a second side 320 connected to each other, the first side 310 being parallel to the first direction D1, The second side 320 is parallel to the second direction D2 and the first direction D1 is perpendicular to the second direction D2. When implemented, the lower light source 400 includes a plurality of light emitting diodes 410 arranged along a first direction D1 on a side 210 of the light guide plate 200 , the side 210 substantially extending from the light guide plate 200 . Be on the light input side.

In practical applications, the light input side 311 of the light collection element 300 can be located on the first side 310 and the upper light source 500 can be located on the first side 310 of the light collection element 300 (as shown in FIG. 2). 2) includes a plurality of light emitting diodes 510 arranged along the first direction D1. Or, in practical applications, the light input side 321 of the light collecting element 300 is located on the second side 320, and the upper light source 500 is located on the second side 320 of the light collecting element 300 (as shown in FIG. 3). includes a plurality of light emitting diodes 510 arranged along the second direction D2.

In practical applications, the bottom surface 340 of the condensing element 300 is provided with striped microstructures whose extending direction is substantially parallel to the first direction D1 and perpendicular to the second direction D2. A plurality of light collection structures 350 were provided. In a preferred embodiment, the light collection element 300 is an inverted prism sheet and the light collection structure 350 has a prism angle 351 so that the light collection structure 350 is a striped microstructure having a prism angle 351 and a prism angle 351 of The tip faces the light guide plate 200 .

In the practical application, as shown in FIG. 7, the light condensing element 300 converts the oblique light rays generated by the light guide plate 200 into normal light rays to be emitted by the light condensing element 300, so that a specific incident light beam can be emitted. In order to improve the directivity of the light guide plate 200, the bottom surface of the light guide plate 200 is used as the reflective surface 230, and a plurality of light guide structures 240 are formed on the reflective surface 230. As shown in FIG. Each light guide structure 240 has a light-receiving surface 241 and a non-light-receiving surface 242 connected to each other, the light-receiving surface 241 facing the light traveling direction of the lower light source 400 and a first light-receiving surface 241 between the light-receiving surface 241 and the reflective surface 230 . is formed, and a second included angle β is formed between the non-light receiving surface 242 and the reflective surface 230, both the first included angle α and the second included angle β are acute angles, and the first included angle α is less than the second included angle β (as shown in FIG. 4). The design of the first included angle α and the second included angle β is such that the light receiving surface The degree of inclination of 241 and non-receiving surface 242 can be varied, and the light beam can be effectively guided to emit light at a positive viewing angle.

In the application of the present application, when only the lower light source 400 is turned on, the display device 1000 only provides light through the lower light guide plate 200, and the light guide structure 240 of the concentrating element 300 converts to normal direction emission. , and implements the narrow viewing angle anti-peeping mode of the backlight module 100 . When both the lower light source 400 and the upper light source 500 are turned on, the light from the lower light source 400 is emitted through the light guide plate 200 and then folded back by the condensing element 300 to be emitted in the normal direction. is folded back by the condensing element 300 and dispersedly emitted, realizing the wide viewing angle sharing mode of the backlight module 100 .

In addition, the light collection element 300 can use diffusing particles to improve the side-viewing energy of the shared mode and provide a wide viewing angle distribution. In practice, when the light collecting element 300 is manufactured, uniformly distributed diffusing particles 301 (as shown in FIG. 5) are provided within the light collecting element 300 to make the light rays passing through the light collecting element 300 more It folds and disperses well, providing a wide viewing angle distribution. Alternatively, the top surface 360 of the light collecting element 300 opposite its bottom surface 340 may be provided with a diffusing particle layer 370 (as shown in FIG. 6) such that the light rays passing through the top surface 360 of the light collecting element 300 are It can be folded and dispersed well, providing a wide viewing angle distribution.

Hereinafter, the principles of the narrow viewing angle peep prevention mode and the wide viewing angle sharing mode will be described in more detail, and the light path applying the backlight module shown in FIG. 3 will be described with reference to FIGS. 7 and 8. FIG. In the backlight module 100, a lower light source 400 and an upper light source 500 are provided for the light guide plate 200 and the light collecting element 300 thereabove, respectively. , the upper light sources 500 installed on the condensing element 300 are arranged along the second direction D2, and the lower light sources 400 and the upper light sources 500 are arranged perpendicular to each other.

When only the lower light source 400 is turned on, the light beam L1 emitted from the lower light source 400 is reflected by the light guide plate 200 with high directivity, and then emitted in the normal direction by the light collecting structure 350 of the light collecting element 300. (upward dashed arrow in FIG. 7) is folded and concentrated, and the light is provided to the display panel 700 only by the light guide plate 200, thereby realizing a narrow viewing angle distribution in the direction of light emitted from the backlight module 100, namely A dashed upward arrow shown in FIG. 7 indicates that light is emitted in the normal direction, and allows the display device 1000 to have a narrow viewing angle peeping prevention mode.

When both the lower light source 400 and the upper light source 500 are turned on, the light beam L1 of the lower light source 400 is reflected by the light guide plate 200 and the light collecting element 300 and emitted in the normal direction, and the light beam L2 of the upper light source 500 is collected. The light is folded back by the light element 300 and emitted in a dispersed manner (upper left and upper right oblique arrows of the dashed line shown in FIG. 8), and at the same time, the light is provided to the display panel 700 by the light guide plate 200 and the light collecting element 300 . 8, in addition to the upward dashed arrow of the normal direction emission in FIG. The diagonal arrow is increased to cause the display device 1000 to display the wide viewing angle sharing mode. Moreover, as described above, the light collection element 300 can improve the side-viewing angle energy of the shared mode by allowing the ray L2 to have better folding dispersion with the diffusing particles, thereby providing a wide viewing angle distribution. can.

In addition, the extending directions of the upper light source 500 and the light collecting structure 350 are respectively parallel to the mutually perpendicular second direction D2 and the first direction D1, that is, the upper light source 500 can be either of the light collecting elements 300 Positioned to one side, the light collection structure 350 exhibits a triangular shape as shown in FIG. 7 when viewed along the first direction D1 and a triangular shape as shown in FIG. , the light from the upper light source 500 can be easily totally reflected, so that the ratio of the obliquely emitted light in the direction away from the upper light source 500 can be further improved. That is, the light intensity represented by the diagonal arrow pointing to the upper right of the dashed line in FIG. The wide-viewing-angle sharing mode that is used is more suitable for onboard displays mounted centrally inside the car, providing either side driver or front passenger viewing.

As can be seen from FIG. 9, in the configuration of the backlight module 100 shown in FIG. Turning on 400 and top light source 500 at the same time improves the emitted light brightness at viewing angles greater than 40 degrees. According to the measurement, when the viewing angle is 40 degrees and 45 degrees, both have the effect of increasing the viewing angle energy.

Further, referring to FIG. 10, FIG. 10 is a schematic side view of the display device to which the embodiment shown in FIG. 2 is applied. In the backlight module 100, a lower light source 400 and an upper light source 500 are provided for the light guide plate 200 and the light collecting element 300 thereabove, respectively. , the upper light source 500 provided in the light collecting element 300 is arranged along the first direction D1, and the lower light source 400 and the upper light source 500 are arranged in the same direction.

As can be seen from FIG. 11, in the configuration of the backlight module 100 of FIG. and the upper light source 500 are turned on at the same time, the emitted light brightness at viewing angles greater than 40 degrees is also improved.

As can be seen from the above embodiments, the present invention provides light sources for the light guide plate and the light collecting element above it, respectively, so that when the lower light source is turned on and the upper light source is turned off, the light emitted from the light guide plate The light beam is folded back and concentrated by the light collecting element to emit in the normal direction, thereby realizing the narrow viewing angle anti-peeping mode of the backlight module, and when both the lower light source and the upper light source are turned on, the guided The light rays emitted from the light plate are not only reflected by the light condensing element and emitted in the normal direction, but also the light rays passing through the light condensing element without passing through the light guide plate are dispersed and emitted, thereby creating a backlight. Realize the wide viewing angle sharing mode of the module. The present application can achieve the function of switching the viewing angle without using a light shielding sheet, and the number of optical plates or optical films required for the present invention is small, so that the overall thickness of the backlight module can be reduced. can be made thinner and the cost can be reduced.

The embodiments disclosed above are merely illustrative of the principles, features and effects of the present invention, and are not intended to limit the practicable scope of the present invention. Modifications and changes can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Any equivalent changes and modifications completed using the disclosed subject matter of the present invention should also fall within the scope of the appended claims.

(conventional)
REFERENCE SIGNS LIST 10 display device 11 display panel 12 first light guide plate 13 light shielding sheet 14 reverse prism sheet 15 second layer light guide 16 reflection sheet 17 first light source 18 second light source (this application)
REFERENCE SIGNS LIST 100 backlight module 200 light guide plate 210 side 230 reflective surface 240 light guide structure 241 light receiving surface 242 non-light receiving surface 300 condensing element 301 diffusion particle 310 first side 320 second side 311, 321 light incident side 340 Bottom surface 350 Condensing structure 351 Prism angle 360 Top surface 370 Diffusion particle layer 400 Lower light source 410, 510 Light emitting diode 500 Upper light source 600 Reflective sheet 700 Display panel 1000 Display device D1 First direction D2 Second direction α First included angle β Second included angle

Claims (12)

a light guide plate;
a lower light source provided adjacent to a side edge of the light guide plate;
a condensing element including a light incident side and a bottom surface, provided above and adjacent to the light guide plate, and having a plurality of light condensing structures provided on the bottom surface toward the light guide plate;
an upper light source provided adjacent to the light incident side of the condensing element;
including,
A backlight module characterized by: the concentrating element includes a first side and a second side connected to each other;
The first side is parallel to the first direction, the second side is parallel to the second direction, and the first direction is perpendicular to the second direction. can be,
the lower light source comprises a plurality of light emitting diodes;
The plurality of light-emitting diodes of the lower light source are arranged along the first direction on the side edge of the light guide plate,
The backlight module according to claim 1, characterized in that: the light incident side of the condensing element is located on the first side;
the upper light source includes a plurality of light emitting diodes;
The plurality of light emitting diodes of the upper light source are arranged along the first direction on the first side of the condensing element,
3. The backlight module according to claim 2, characterized in that: the light incident side of the condensing element is located on the second side;
the upper light source comprises a plurality of light emitting diodes;
the plurality of light-emitting diodes of the upper light source are arranged along the second direction on the second side of the light-condensing element;
3. The backlight module according to claim 2, characterized in that: each light-condensing structure is a striped microstructure whose extending direction is parallel to the first direction and perpendicular to the second direction;
3. The backlight module according to claim 2, characterized in that: The condensing element is an inverted prism sheet,
each said light collection structure has a prism angle with a tip pointing towards said light guide plate;
The backlight module according to claim 1, characterized in that: The bottom surface of the light guide plate is a reflective surface, and a plurality of light guide structures are formed on the reflective surface.
The backlight module according to claim 1, characterized in that: each light guiding structure has a light receiving surface and a non-light receiving surface connected to each other;
The light-receiving surface faces the light traveling direction of the lower light source, a first included angle is formed between the light-receiving surface and the reflecting surface, and a second included angle is formed between the non-light-receiving surface and the reflecting surface. an included angle is formed, the first included angle being acute and less than the second included angle;
8. The backlight module according to claim 7, characterized in that: uniformly distributed diffusing particles are provided within the light collecting element;
The backlight module according to claim 1, characterized in that: a top surface of the condensing element facing the bottom surface has a diffusing particle layer;
The backlight module according to claim 1, characterized in that: further comprising a reflective sheet provided below the light guide plate;
The backlight module according to claim 1, characterized in that: a display panel;
a backlight module according to any one of claims 1 to 11,
A display device, wherein the display panel is provided above and adjacent to the backlight module.