TW201516532A - Transparent display device and backlight module used therein - Google Patents

Abstract

A display device including a backlight module and a display panel disposed on the backlight module is provided. The backlight module has a light module and a light guide plate that include a plate body and a light entrance unit. The plate body has a light exit surface and a light entrance side located on an edge of the light exit surface. The light entrance unit is connected to the light entrance side, and the light module is disposed corresponding to the light entrance unit. Light generated from the light module enters the plate body through the light entrance unit, wherein the light has a narrower light field after passing the light entrance unit.

Description

Transparent display device and backlight module used thereby

The present invention relates to a display device and a backlight module thereof; in particular, the present invention relates to a partially see-through display device and a backlight module thereof.

In recent years, flat display devices have been widely used in various fields, and can be used alone as displays or embedded in electronic devices for information display. There are many types of flat display devices, such as organic light-emitting diode displays, liquid crystal displays, electrophoretic displays, etc. Among them, liquid crystal displays are currently the most common flat display devices.

In the conventional liquid crystal display device, only the display of the image is provided, and the rear view cannot be seen through the display device. However, in the recent development direction, in order to meet the needs of specific use, there has been a display device with a see-through perspective. As shown in FIG. 1, the presently permeable liquid crystal display device 1 can simultaneously include a see-through range 11 and a display range 13 in its display area 10; that is, the display range 13 can be displayed while the perspective range 11 is set to be transparent. Therefore, the user can see the rear scene through the perspective range 11 while viewing the display information in the display range 13.

In order to display images or information in the display range 13, it is necessary to provide a backlight behind the display range 13, and then to control the degree of penetration of the backlight by the liquid crystal layer to generate images or information. only When the backlight is generated, part of the backlight may leak out of the area covered by the display range 13 to the area covered by the see-through range 11. This light leakage phenomenon will affect the transparency in the perspective range 11, and it is impossible to see through the perspective range 11 and clearly see the rear scene.

It is an object of the present invention to provide a display device and a backlight module that can reduce the chance of light leakage in a transparent region.

Another object of the present invention is to provide a display device and a backlight module that can increase the transparency of a transparent region.

Another object of the present invention is to provide a backlight module that can control a generation area of a backlight.

The display device comprises a display panel and a backlight module. The display panel is disposed on the backlight module and has a see-through area and a display area. The backlight module comprises a light guide plate and a light source module; the light guide plate comprises a body and a light incident portion. The body has a light-emitting surface and a light-incident side, wherein the light-incident side is located at an edge of the side of the light-emitting surface. The light entering portion is connected to the light incident side of the main body, and the projection of the display area of the display panel on the main body forms a display corresponding area, and the position where the light incident part is connected to the light side corresponds to the display corresponding area. The light source module is disposed corresponding to the light incident portion, and generates light entering the body through the light incident portion, and the light passes through the light incident portion and has a lighter shape than before passing through the light incident portion.

Specifically, the light incident portion has a plurality of light incident channels arranged side by side and spaced apart; each of the light incident passages has an light incident end and an light exit end. The light output end is connected to the light incident side. The light source module has a plurality of light sources, and each light source is disposed corresponding to the light entrance end of the light path. The light source generates light from the light entrance end into the light entrance channel, and some or all of the incoming light is reflected through the side of the light entrance channel Then enter the body through the light exit end and the light entrance side.

100‧‧‧ display panel

110‧‧‧ Perspective area

130‧‧‧ display area

300‧‧‧Backlight module

400‧‧‧Into the light channel

401‧‧‧Bridge

410‧‧‧Into the light end

430‧‧‧ light end

450‧‧‧ side

500‧‧‧Light guide plate

510‧‧‧ Ontology

511‧‧‧Glossy

513‧‧‧light side

515‧‧‧display corresponding area

517‧‧ ‧ perspective corresponding area

530‧‧‧Into the Department of Light

533‧‧‧Light absorbing layer

535‧‧‧Air gap

570‧‧‧Optical adhesive layer

700‧‧‧Light source module

710‧‧‧Light source

711‧‧‧Lighting surface

730‧‧‧Direct light source

1 is a schematic view of a conventional transparent display device; FIG. 2 is an exploded view of an embodiment of a display device and a backlight module of the present invention; FIG. 3 is a top view of an embodiment of a light guide plate; 5A and FIG. 5B are schematic views of another embodiment of the light incident portion; FIGS. 6A and 6B are schematic views of another embodiment of the light incident portion; FIG. 7A is a top view of the embodiment in which the light absorbing layer is added; FIG. 7F is a schematic diagram of the effect of the light field when the lengths of the different light absorbing layers are taken; FIG. 8 is a schematic view of another embodiment of the backlight module; FIG. 9 is a schematic diagram of an embodiment of the additional connection arrangement of the light entering part; FIG. A top view of an embodiment having a plurality of light incident portions.

The present invention provides a see-through display device and a backlight module therefor. In a preferred embodiment, the display device can include a liquid crystal display device, and preferably can include a backlight module that uses an edge-lit light source.

In the embodiment shown in FIG. 2, the display device includes a display panel 100 and a backlight module 300. The display panel 100 is disposed on the backlight module 300 and has a see-through area 110 and a display area. 130. The see-through area 110 is adjacent to the display area 130, and the see-through area 110 is preferably disposed at a position near the side of the display panel 100. In the preferred embodiment, the fluoroscopy area 110 is displayed under different operating modes, and the display area 130 can also display images and information. In contrast, the display area 130 can also be set to be transparent when not displayed. In order to let the rear ambient light pass through, and the rear view can be seen from the front of the display device.

As shown in FIG. 2 , the backlight module 300 includes a light guide plate 500 and a light source module 700 . The light guide plate 500 includes a body 510 and a light incident portion 530. The body 510 has a light-emitting surface 511 and a light-incident side 513, wherein the light-incident side 513 is located at an edge of the side of the light-emitting surface 511. In the embodiment, the backlight module 300 is preferably a side-lit backlight module, and the light-emitting surface 511 is parallel to the body 510 and faces the surface of the display panel 100. The body 510 is preferably a transparent or translucent material. Therefore, when the body 510 is overlapped with the display panel 100, the rear view can be seen through the display panel 100 and the light guide plate 500 from the front of the display device.

The light incident portion 530 is connected to the light incident side 513 of the body 510. The connection here may be an integral connection or an additional connection. As shown in FIG. 2 and FIG. 3, the projection of the display area 130 of the display panel 100 on the main body 510 forms a display corresponding area 515, and the position where the light incident part 530 is connected to the light side 513 is preferably only related to the display corresponding area 515. correspond. In other words, the light entering the body 510 from the light incident portion 530 mainly enters the range of the display corresponding region 515. The light source module 700 is disposed corresponding to the light incident portion 530 , and generates light entering the body 510 via the light incident portion 530 . In the preferred embodiment, the light passes through the light entering portion 530 and has a more converging light pattern before passing through the light incident portion 530; in other words, the intensity distribution of the light after passing through the light incident portion 530 is concentrated in the center of the light emitting front surface. The position, or the distribution of light after passing through the light entrance portion 530, is relatively closer to the normal to the front side of the light.

The light incident portion 530 has a plurality of light incident channels 400 arranged side by side and spaced apart. Each of the light incident channels 400 is preferably independent of each other and has an light incident end 410 and a light exit end 430, respectively. The light-emitting end 430 is coupled to the light-incident side 513, and allows light to enter the light-input channel 400 through the light-incident end 410, and then enters the body 510 through the light-emitting end 430 and the light-incident side 513; in other words, the light-emitting end 430 and the light-emitting end 430 The light side 513 has a structural connection relationship and a light conduction connection relationship, and the light entering the light path 400 can enter the light incident side 513 via the light exit end 430.

As shown in FIG. 3, the light source module 700 has a plurality of light sources 710, and each of the light sources 710 is disposed corresponding to the light incident end 410 of the light tunnel 400. The light source 710 is preferably a light emitting diode, and the light source module 700 is preferably a light strip composed of a light emitting diode. The light source 710 generates light from the light incident end 410 into the light entrance channel 400, and some or all of the incoming light is reflected by the light incident channel 400 side 450 and then passes through the light exit end 430 and the light incident side 513 into the body 510. The side 450 of the light entrance channel 400 is the edge of the light entrance channel 400 connected between the light incident end 410 and the light exit end 430, which is preferably perpendicular to the light incident side 513. The side 450 preferably reflects the light entering the light tunnel 400 in a total reflection manner, so that the light can continue to travel forward; however, in different embodiments, a reflective material or a reflective sheet may be added to the side 450. To reflect light entering the light tunnel 400.

In the embodiment shown in FIG. 3, the light-incident channel 400 is preferably formed as a light-transmissive rectangular plate, and the light-incident end 410 and the light-emitting end 430 are respectively opposite short ends of the light-transmissive rectangular plate; the side 450 is transparent. The long side of the light rectangular plate. With this design, the light entrance channel 400 is effective to reduce the opening angle of the light during the passage of the light into the light tunnel 400 to produce a converging effect.

As shown in FIG. 4, the light generated by the light source 710 has an opening angle θ before entering the light incident end 410. Preferably, the angle of the light refers to an angle at which the light covers a range from the line N of the light-emitting surface 711 of the light source 710. When entering the light entrance channel 400, the light closer to the center line N, such as an opening angle smaller than □ In part, the light exiting end 430 can be emitted without contacting the side edge 450, so that the opening angle of the portion of the light is less than □. As for the portion of the ray opening angle between θ and □, the portion closer to the center line N can be transmitted to the front self-exiting end 430 by the total reflection provided by the side 450, and a few of the excessively large angles are It is possible to emit light directly from the side 450, or otherwise change its angle and then forward. With this design, the opening angle of the light entering the light-incident end 410 can be greater than the opening angle of the light-emitting end 430, so that the effect of so-called light converging can be produced. Since the light has a small opening angle after the converging, it is relatively difficult to leave the range of the display corresponding area 515 after entering the body 510, and the influence on the transparent corresponding area 517 next to the display corresponding area 515 is reduced. In the preferred embodiment, when the light exits the light incident portion 530 and enters the light incident side 513, the angle of the light deflected toward the see-through corresponding region 517 is less than 8 degrees.

As shown in FIG. 4, in order to allow the light having a larger opening angle to enter the body 510 after the second or more reflections, as shown by the traveling path of the light x, the side 450 preferably needs to have a certain length. When the light with a large opening angle is reflected after multiple times, loss can be generated on the one hand, and a light absorbing material can be added at the reflection position on the other hand to further reduce the strength. In the preferred embodiment, when the total reflection angle of the material of the light entrance channel 400 is R, the length of the side edge 450, that is, the length of the light-transmissive rectangular plate perpendicular to the light-incident side 513, is at least greater than 1.5 tan (R). Multiply by the width of the light incident end 410. If the general material refractive index is between 1.4 and 1.6, that is, the total reflection angle is between 38 and 45 degrees, for example, when the total reflection angle is 41.8 degrees, the length of the side 450 is preferably larger than The length of the light incident end 410 is 1.34 times. In a more preferred embodiment, the length of the side edge 450 is about twice the width of the light incident end 410.

As described above, the fluoroscopy area 110 can display the image and the information as the display area 130 under different operation modes. In contrast, the display area 130 can also be set to be transparent when not displayed. The rear ambient light passes through. As shown in the embodiment of FIG. 5A, the whole The light incident portion 513 is distributed with the light incident portion 530 and the light source module 700. When the part of the light source module 700 is illuminated to generate light into the light incident portion 530, the block 510 corresponding to the light incident portion 530 is the display area 130 for displaying images; and the remaining corresponding unlit light source modules The area of 700 is a see-through area 110 that allows the rear ambient light to pass through to create a see-through effect.

In the embodiment shown in FIG. 5B, as in the previous embodiment, the body 510 includes adjacent display corresponding regions 515 and transparent corresponding regions 517. When the light entrance channel 400 extends from the light incident end 410 to the light exit end 430, it is inclined away from the perspective corresponding area 517 by an angle ω; the angle ω is preferably within 8 degrees, so as to balance the angle of the guiding light and the module space design. Convenience. As shown in FIG. 5B, since the display corresponding region 515 is disposed at a position close to the edge of the body 510, the light entrance passage 400 is deflected toward the edge of the body 510. With this design, the light that originally entered the body 510 after entering the body 510 may be biased toward the perspective corresponding area 517, and may be guided to reduce the angle of deflection toward the perspective corresponding area 517. In addition, in the modified embodiment, the light incident end 410 can also be adjusted to be perpendicular to the extending direction of the light incident portion 400, and the set angle of the light source 710 can also be adjusted to be inclined to improve the light use efficiency.

In the embodiment shown in FIG. 6A, the light entrance channel 400 is converged from the light incident end 410 toward the light exit end 430; in other words, the width of the incoming light 410 is greater than the width of the light exit end 430. With this design, the light entering the light entrance channel 400 can be further brought closer to the center line N when reflected through the side edge 450, thereby generating the effect of light converging. In the embodiment of FIG. 6B, the light-incident channel 400 may also have the above-mentioned converging design at a portion close to the light-incident end 410, and adopt an original rectangular design at a portion close to the light-emitting end 430 to adjust the light converging. Degree.

Fig. 7A shows another embodiment of the light incident portion. In this embodiment, the light incident portion 530 has a plurality of light absorbing layers 533 respectively disposed on the side 450 of the light entrance channel 400 between the light incident end 410 and the light exit end 430, and is preferably disposed in the light incident channel 400 facing away from the light incident channel 400. See through the side of the corresponding area 517 Side 450. In other words, as shown in FIG. 7A, when the light reaches the side 450 where the light absorbing layer 533 is provided, it is at least partially absorbed by the light absorbing layer 533 and is no longer reflected to the see-through corresponding region 517. In addition, the light absorbing layer 533 preferably only corresponds to the see-through corresponding region 517, that is, the light absorbing layer 533 itself faces or faces the see-through corresponding region 517 within a range of tilt angles. With this design, the light deflected toward the perspective corresponding region 517 can be further reduced. In addition, the light absorbing layer 533 preferably extends from the light exit end 430 toward the light incident end 410 to avoid prematurely absorbing light and causing poor light use efficiency.

In the preferred embodiment, as shown in FIG. 7A, the length l of the light absorbing layer 533 is smaller than the length L of the light entrance channel 400. 7B to 7F are test results when the ratio of the length l of the light absorbing layer 533 to the width W of the light incident end is different, wherein the coordinates on the radial direction on the graph indicate the intensity of the light distribution; and the scale on the circular arc corresponding to the central angle of the circle Then it is the opening angle with respect to the normal line of the light-emitting end 430. As can be seen from the results shown in the figure, when the length l of the light absorbing layer 533 is twice the width W of the light incident end, the angle of the light measured from the light exiting end 430 has a converging effect. When the length l of the light absorbing layer 533 is greater than 2.5 times the width W of the light incident end, the angle of the light measured from the light exiting end 430 can be confined within 10 degrees.

In the embodiment shown in FIG. 8 , the light source module 700 is provided with one or more direct light sources 730 in addition to the light source 710 corresponding to the light incident portion 530 . The direct light source 730 is disposed along the light incident side 513 and corresponds to the transparent corresponding region 517 adjacent to the display corresponding region 515. When the transparent corresponding area 517 needs to show an influence, the direct light source 730 generates a portion where the light is incident on the transparent corresponding area 517 in the body 510. When the transparent corresponding area 517 is set to the transparent state, the direct light source 730 stops generating light into the transparent corresponding area 517.

As shown in FIG. 9, in this embodiment, the light incident portion 530 can be connected to the light incident side 513 in an additional manner. Preferably, the light incident portion 530 can be attached to the light incident side 513 by the optical adhesive layer 570; The optical adhesive layer 570 preferably has the same or similar refractive index as the light incident portion 530 or the body 510. The refractive index of the light incident portion 530 is preferably the same as or similar to the refractive index of the body 510; however, in different embodiments, the refractive index of the light incident portion 530 may also be greater than the refractive index of the body 510 to reduce the light entering the body 510. A condition that deviates due to refraction. As shown in FIG. 9 , the light incident portion 530 further includes at least one bridge portion 401 , and the bridge portion 401 is connected to the adjacent two light entrance channels 400 respectively at a position close to the light exit end 430 . In other words, the bridging portion 401 is located between the adjacent light-input channels 400, so that the adjacent light-input channels 400 can be connected by the bridging portion 401 to form a linkage, and the structure can provide better strength. In the preferred embodiment, the edge of the bridge portion 401 is aligned with the light-emitting end 430 of the connected light-input channel 400. By this arrangement, the adjacent light-input end 430 and the bridge portion 401 between the adjacent ends can be connected. The same plane is used to increase the contact area with the light-incident side 513 and the optical adhesive layer 570, thereby improving structural stability.

In the embodiment shown in FIG. 10, the light guide plate 500 has a plurality of light incident portions 530 distributed along the light incident side 513. At this time, the body 510 may have a plurality of adjacent display corresponding regions 515, and each of the light incident portions 530 respectively correspond to different display corresponding regions 515. In use, the plurality of display corresponding areas 515 can simultaneously display images or only some of them display images, while the other display corresponding areas 515 are transparent for the user to see through the rear scene. An air gap 535 is sandwiched between the adjacent light incident portions 530; the barrier of the air gap 535 can reduce the possibility of light passing between the different light incident portions 530, and at the same time reduce the transparency of the adjacent display corresponding regions 515. The effect of the state. In addition, different light-input units 530 may be selected to correspond to the same light source module 700, and different light source modules 700 may be configured to correspond.

The present invention has been described by the above-described related embodiments, but the above embodiments are merely examples for implementing the present invention. It should be noted that the disclosed embodiments do not limit the scope of the present invention. Wai. On the contrary, modifications and equivalents of the spirit and scope of the invention are included in the scope of the invention.

100‧‧‧ display panel

110‧‧‧ Perspective area

130‧‧‧ display area

300‧‧‧Backlight module

400‧‧‧Into the light channel

410‧‧‧Into the light end

430‧‧‧ light end

450‧‧‧ side

500‧‧‧Light guide plate

510‧‧‧ Ontology

511‧‧‧Glossy

513‧‧‧light side

515‧‧‧display corresponding area

517‧‧ ‧ perspective corresponding area

530‧‧‧Into the Department of Light

535‧‧‧Air gap

700‧‧‧Light source module

710‧‧‧Light source

Claims (17)

A backlight module includes: a light guide plate, comprising: a body having a light emitting surface and a light incident side; wherein the light incident side is located at one side of the light emitting surface; and a light incident portion is disposed to be connected a light entering side; wherein the light incident portion has a plurality of light incident channels arranged side by side and spaced apart, each of the light incident passages having an light incident end and an light exit end, wherein the light exit ends are respectively coupled to the light incident side; a light source module having a plurality of light sources, each of the light sources being disposed corresponding to each of the light incident ends; wherein the light source generating light passes through the light incident ends into the light entrance channels and penetrates respectively The light incident side enters the body again, and a portion of the light passes through the light incident side and passes through the light incident side to enter the body. The backlight module of claim 1, wherein the light-incident channel forms a light-transmissive rectangular plate, and the light-incident end and the light-emitting end are respectively opposite short ends of the light-transmissive rectangular plate. The backlight module of claim 2, wherein when the material refractive index of the transparent rectangular plate is between 1.4 and 1.6, the length of the light-transmissive rectangular plate perpendicular to the light-incident side is at least greater than the width of the light-incident end. 1.34 times. The backlight module of claim 1, wherein the light incident portion further comprises at least one bridge portion, wherein the bridge portion is connected to the adjacent two of the light entrance channels at a position close to the light exit end. The backlight module of claim 4, wherein a side of the bridge portion is aligned with the light exit end of the light entrance channel. The backlight module of claim 1 , wherein the plurality of light incident portions are distributed along the light incident side, wherein a gap is formed between the adjacent two light incident portions. The backlight module of claim 6, comprising a plurality of the light sources respectively corresponding to the light entering portions The light entrance channels; wherein the light sources are selectively illuminated at different times. The backlight module of claim 1, wherein the body comprises an adjacent one of a perspective corresponding area and a display corresponding area, wherein the light incident portion is only corresponding to the display corresponding area. The backlight module of claim 8, comprising a plurality of light absorbing layers respectively disposed on one side of the light entrance end between the light incident end and the light exit end, and the light absorbing layers only correspond to the perspective light sensing layer The zone is disposed and located at a side of the light entrance channel facing away from one of the corresponding areas of the perspective. The backlight module of claim 9, wherein the length of the light absorbing layer along the light entrance channel is greater than 2.5 times the width of the light incident end. The backlight module of claim 1, wherein the body comprises an adjacent one of the perspective corresponding area and a display corresponding area, the light entering part is disposed corresponding to the display corresponding area, and the light source module comprises a direct light source corresponding to In the corresponding area of the perspective, and providing light into the corresponding area of the perspective. The backlight module of claim 1, wherein the body comprises an adjacent one of a perspective corresponding area and a display corresponding area, and the light entering part is disposed corresponding to the display corresponding area, and the light entrance channel is from the light entrance end The light exiting end is extended at an angle away from the perspective corresponding region. The backlight module of claim 1, wherein the light entrance channel is converged from the light incident end toward the light exit end. A backlight module includes: a light guide plate, comprising: a body having a light incident side; and a light incident portion connected to the light incident side; and a light source module disposed corresponding to the light incident portion and generating The light enters the body through the light incident portion; wherein the light generated by the light source module passes through the light incident portion and passes through the light incident portion. The backlight module of claim 14, comprising an adjacent one of a perspective corresponding area and a display corresponding area, wherein the light incident portion is only corresponding to the display corresponding area, and when the light leaves the light entering part, the light enters the light entering the light entering part On the light side, the angle of the light deflected toward the corresponding area of the perspective is less than 8 degrees. The backlight module of claim 14, wherein the light incident portion has a plurality of light incident channels arranged side by side and spaced apart, and each of the light incident passages has an light entrance end and an light exit end, and the light exit ends are respectively connected The light source module has a plurality of light sources, each of which is disposed corresponding to each of the light incident ends; the angle of the light source entering the light incident end is greater than the opening angle of the light exiting the light exiting end . A display device, comprising: the backlight module of any one of claims 1 to 16; and a display panel disposed on the backlight module and having an adjacent one of a see-through area and a display area; The projection of the display area on the body forms a display corresponding area, and the light entering part corresponds to the corresponding area setting.