CN106195726B - Display device and backlight module thereof - Google Patents

Abstract

The invention provides a display device and a backlight module (back light module) thereof. The backlight module comprises: a first light emitting module, a second light emitting module and a light attenuating element. The first light-emitting module is provided with a light-emitting surface; the second light-emitting module is positioned on the opposite side of the light-emitting surface; the light attenuation element is positioned between the first light emitting module and the second light emitting module and comprises a first polarizing plate with a first light absorption axis.

Description

Display device and backlight module thereof

technical field

The present invention relates to a display device and its back light module, and in particular to a switchable 2D/3D image display device and its back light module.

Background technique

Generally speaking, three dimensional displays can be divided into stereoscopic type and autostereoscopic type. Among them, the naked-eye display is equipped with special optical elements inside, such as a parallax barrier or a lenticular lens, so that the left and right eyes of the user can respectively observe the image with parallax on the display device, forming a sense of perception. Stereoscopic image. In order to meet the needs of users to watch two-dimensional (2D) images at the same time, a switchable 2D/3D display device is proposed, allowing users to switch between two display modes of 3D images and 2D images.

A typical switchable 2D/3D display device includes a 3D light emitting module and a 2D light emitting module. When displaying a 3D image, the 2D light emitting module can be turned off and only the 3D light emitting module emits light. Let the light emitted by the three-dimensional light-emitting module pass through the image display panel, such as a liquid crystal display panel (Liquid Crystal Display, LCD), to generate images with parallax and be received by the user's left and right eyes respectively, allowing the user to perceive three-dimensional image. When displaying two-dimensional images, the two-dimensional light-emitting module can be turned on, and the three-dimensional light-emitting module can be turned off or slightly opened to supplement light. After the light passes through the three-dimensional light-emitting module and the image display panel, a two-dimensional image is provided to the user.

However, when displaying a 3D image, the light emitted by a part of the 3D light-emitting module does not directly pass through the image display panel, but first shoots to the 2D light-emitting module, and after being reflected by the 2D light-emitting module, enters the user's eyes, resulting in Unexpected bright and dark moirés arranged alternately and crosstalk with the image of the display panel will reduce the display quality of the autostereoscopic image display device.

Therefore, there is still a need to provide an advanced display device and its backlight module to improve the problems faced by the known technologies.

Contents of the invention

An embodiment of the present invention provides a backlight module, which includes: a first light emitting module, a second light emitting module, and a light attenuator. Wherein, the first light-emitting module has a light-emitting surface; the second light-emitting module is located on the opposite side of the light-emitting surface; the light attenuating element includes a first polarizer with a first light absorption axis, and the first polarizer is located between the first light-emitting module and between the second light-emitting modules.

Another embodiment of the present invention relates to a display device, which includes a display panel and a backlight module. Wherein, the display panel includes a lower polarizer and an upper polarizer opposite to each other, and respectively have a first polarization axis and a second polarization axis orthogonal to each other. The backlight module includes a first light emitting module, a second light emitting module and a light attenuating element. Wherein, the first light-emitting module has a light-emitting surface facing the lower polarizing plate; the second light-emitting module is located on the opposite side of the light-emitting surface; the light attenuating element is located between the first light-emitting module and the second light-emitting module, and includes a first A first polarizer of the light absorption axis. Wherein the first light absorption axis is substantially parallel to the first polarization axis of the lower polarizer.

Yet another embodiment of the present invention relates to a backlight module, the backlight module includes a first light emitting module, a second light emitting module, a reflection sheet and a light attenuating element. Wherein, the first light-emitting module has a light-emitting surface; the reflective sheet is located on the opposite side of the light-emitting surface; the second light-emitting module is located between the first light-emitting module and the reflective sheet; the light attenuating element includes a polarizer and a phase difference plate. The polarizing plate has a light absorption axis and is located between the second light-emitting module and the reflective sheet; the retardation plate is located between the polarizing plate and the reflective sheet.

Another embodiment of the present invention relates to a display device, which includes a display panel and a backlight module. Wherein, the backlight module includes a first light emitting module, a reflection sheet, a second light emitting module and a light attenuating element. The first light-emitting module has a light-emitting surface facing the display panel; the reflective sheet is located on the opposite side of the light-emitting surface; the second light-emitting module is located between the first light-emitting module and the reflective sheet; the light attenuating element includes a polarizer and a phase difference plate. The polarizing plate has a light absorption axis and is located between the second light emitting module and the reflection sheet. The retardation plate is located between the polarizing plate and the reflection sheet.

According to the above, the embodiments of the present invention provide a display device with a 2D/3D switchable display mode and a backlight module thereof. In some embodiments of the present invention, the backlight module of the display device at least includes a first light-emitting module and a second light-emitting module arranged parallel to each other, and at least Two display modes of 2D and 3D. Wherein, the first light-emitting module has a light-emitting surface, and a light-attenuating element including at least one absorbing polarizer is arranged on the opposite side of the light-emitting surface to prevent the light emitted by the first light-emitting module from entering the second light-emitting module. A part of the light is reflected by the second light-emitting module to produce unexpected bright and dark moiré patterns, thereby preventing crosstalk between the part of the light and the light emitted by the first light-emitting module and directly passing through the light-emitting surface. The display quality when the display device adopts the first light-emitting module can be improved without affecting the display quality when switching to another display mode.

Description of drawings

In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

FIG. 1A is a schematic cross-sectional view of a backlight module according to an embodiment of the present invention;

FIG. 1B is an enlarged cross-sectional schematic diagram of a partial structure of a light attenuating element shown in FIG. 1A;

2A is a schematic cross-sectional view of a backlight module according to another embodiment of the present invention;

FIG. 2B is an enlarged cross-sectional schematic diagram of a partial structure of a light attenuating element shown in FIG. 2A;

3A is a schematic cross-sectional view of a backlight module according to yet another embodiment of the present invention;

FIG. 3B is an enlarged cross-sectional schematic diagram of a partial structure of a light attenuating element shown in FIG. 3A;

4A is a schematic cross-sectional view of a backlight module according to yet another embodiment of the present invention;

4B is a schematic cross-sectional view of a backlight module according to yet another embodiment of the present invention;

FIG. 4C is an enlarged cross-sectional schematic diagram of a partial structure of a light attenuating element shown in FIG. 4A and FIG. 4B;

FIG. 5 is a schematic cross-sectional view of a display device according to an embodiment of the present invention; and

FIG. 6 is a schematic cross-sectional view of a display device according to another embodiment of the present invention.

The component numbers in the figure are explained as follows:

50: Display device 51: Display panel

51a: liquid crystal layer 51b: lower polarizer

51c: upper polarizer 60: display device

100: backlight module 101: first light emitting module

101a: light-emitting surface 102: second light-emitting module

103: Light attenuation element 104: Light guide plate

104a: light incident surface 104b: light incident surface

104c: first side 104d: second side

105: Light emitting unit 106: Light guide element

107: Light guide plate 107a: Light incident surface

107b: third side 107c: fourth side

108: Light emitting unit 109: Reflector

110: first polarizing plate 110a: first substrate layer

110b: second substrate layer 110c: polarizing layer

112: Diffusion plate 113: Brightness enhancement film

114: reflective polarized brightness enhancement film 200: backlight module

203: light attenuation element 210: second polarizer

210a: third substrate layer 210b: fourth substrate layer

210c: polyvinyl alcohol layer 211: adhesive layer

300: Backlight module 303: Light attenuation element

312: Optical film 400A: Backlight module

400B: Backlight module 403: Light attenuation element

412: Optical film 504: Surface treatment structure

600: backlight module 603: light attenuation element

609: reflector 610: polarizer

611: Retardation plate X1: First optical absorption axis

X2: Second light absorption axis X3: Light absorption axis

T1, T3, T4: light transmission axis P1: first polarization axis

P2: second polarization axis

L1, L1a, L1b, L1b1, L1b2, L2, L2a, L2b, L2c: Light

Detailed ways

The invention provides a backlight module with two light-emitting modules and a display device using the backlight module, which can improve the image crosstalk problem caused by light reflection between the two light-emitting modules, and achieve the effect of improving the quality of the display device. In order to make the above-mentioned embodiments and other objects, features and advantages of the present invention more comprehensible, several preferred embodiments are specifically cited below and described in detail with accompanying drawings.

However, it must be noted that these specific implementation cases and methods are not intended to limit the present invention. The invention can still be implemented with other features, elements, methods and parameters. The proposal of the preferred embodiment is only used to illustrate the technical characteristics of the present invention, and is not used to limit the patent scope of the present invention. Those with ordinary knowledge in this technical field will be able to make equivalent modifications and changes according to the descriptions in the following specification without departing from the spirit of the present invention. In different embodiments and drawings, the same elements will be represented by the same element symbols.

Please refer to FIG. 1A . FIG. 1A is a schematic cross-sectional view of a backlight module 100 according to an embodiment of the present invention. The backlight module 100 includes: a first light emitting module 101 , a second light emitting module 102 and a light attenuating element 103 . In some embodiments of the present invention, the first light emitting module 101 is located above the second light emitting module 102 , and the light attenuating element 103 is located between the first light emitting module 101 and the second light emitting module 102 . In detail, the first light-emitting module 101 mainly used for three-dimensional display is a structure with both light-emitting and light-transmitting structures, and has a light-emitting surface 101a, and the light L1 emitted by the light source of the first light-emitting module 101 passes through the light-emitting surface 101a The second light-emitting module 102 mainly used for two-dimensional display is located on the opposite side of the light-emitting surface 101a of the first light-emitting module 101, and the light L2 emitted by the light source of the second light-emitting module 102 passes through the second light-emitting module 102 After that, it passes through the first light-emitting module 101 and is led out from the light-emitting surface 101 a of the first light-emitting module 101 . The light-emitting surface 101a represents the end surface of the backlight module 100 where the light is emitted. In this embodiment, it is the surface of the optical components of the first light-emitting module that is closest to the image display panel and the viewer.

In some embodiments of the present invention, the first light emitting module 101 may include a light guide plate 104 , at least one light emitting unit 105 and a plurality of light guide elements 106 . Wherein, the light guide plate 104 has at least one light incident surface 104a or 104b and a first side 104c and a second side 104d opposite to each other. The material of the light guide plate 104 can be glass, polymethylmethacrylate (PMMA) or other possible light-transmitting materials (but not limited thereto). The light emitting unit 105 is adjacent to the light receiving surface 104a or 104b. The light emitting unit 105 in this embodiment is adjacent to the light receiving surface 104b. Surface 104b. A plurality of light guide elements 106 are disposed on at least one of the first side 104c and the second side 104d.

In this embodiment, the first light-emitting module 101 is a side-light light-emitting module, which has a plurality of light-emitting units 105 adjacent to light incident surfaces 104 a and 104 b parallel to the thickness direction of the light guide plate 104 . The first side 104c perpendicular to the thickness direction of the light guide plate 104 can be used as the light-emitting surface 101a of the first light-emitting module 101. The first side 104c is the surface of the backlight module 100 closest to the display panel and the observer, and is also the surface of the light guide plate 104. surface. The light guide element 106 is located on the second side 104 d opposite to the first side 104 c, that is, located on the lower surface of the light guide plate 104 . However, in other embodiments, the light guide element 106 may also be disposed only on the first side 104c or simultaneously disposed on the first side 104c and the second side 104d.

In some embodiments of the present invention, the light guide element 106 may be regularly or irregularly arranged protrusions, ridges, slots, openings, and recesses. In addition, the cross-sectional shape of each light guide (observed from the direction parallel to the first side 104c and the second side 104d) can be arc, polygon (including triangle, square, rectangle, trapezoid, regular polygon) or irregular The shape can be used to destroy the total reflection effect of the light guide plate 104, so that the light energy can be emitted toward the light output surface 101a (ie, the first side 104c of the light guide plate 104) through reflection or scattering. The light guide element 106 achieves the formation of a grid-like light-emitting pattern (barrier pattern) with different light-emitting intensities in different regions (generating bright areas or dark areas) through the stripe-like distribution pattern, so that most of the light L1a emitted by the light-emitting unit 105 is in the After entering the light guide plate 104 , guided by the light guide elements 106 , the display panel is irradiated in the form of alternating light and dark to present a three-dimensional image.

The second light emitting module 102 may include a light guide plate 107 , at least one light emitting unit 108 and a reflective sheet 109 . Wherein, the light guide plate 107 is located between the reflective sheet 109 and the light guide plate 104 of the first light emitting module 101 , and has at least one light incident surface 107 a and a third side 107 b and a fourth side 107 c opposite to each other. The light emitting unit 108 is adjacent to the light receiving surface 107a. The third side 107b of the light guide plate 107 corresponds to the second side 104d of the light guide plate 104 of the first light emitting module 101 ; the reflective sheet 109 corresponds to the fourth side 107c of the light guide plate 107 . The reflective sheet 109 is made of white scattering material. After the light L2 emitted by the light-emitting unit 108 enters the light guide plate 107, part of the light L2a directly passes through the first light-emitting module 101, and the other part of the light L2b is first reflected by the reflective sheet 109, and then passes through the second light-emitting module 102 and the first light-emitting module 101 are led out from the light-emitting surface 101a of the first light-emitting module 101 (ie, the first side 104c of the light guide plate 104 of the first light-emitting module 101), thereby forming a surface light source.

The light attenuating element 103 is located between the first light emitting module 101 and the second light emitting module 102 . In some embodiments of the present invention, the light attenuating element 103 includes at least one absorbing linear polarizer, such as the first polarizer 110 , and the first polarizer 110 has a first light absorption axis X1. In this embodiment, the light attenuating element 103 may be composed of a single first polarizer 110 . Please refer to FIG. 1B . FIG. 1B is an enlarged cross-sectional schematic diagram of a partial structure of a light attenuating element 103 shown in FIG. 1A . The first polarizing plate 110 includes a first substrate layer 110a, a second substrate layer 110b, and a polarizing layer 110c (polyvinyl alcohol Poly-Vinyl Alcohol) interposed between the first substrate layer 110a and the second substrate layer 110b. , PVA), the polarizing layer 110c can form an anisotropic light absorption rate (anisotropic) function by stretching and absorbing material distribution to achieve the result of polarization. Wherein, the materials constituting the first substrate layer 110a and the second substrate layer 110b can be the same or different; and the materials constituting the first substrate layer 110a and the second substrate layer 110b can be selected from cellulose triacetate (Triacetate Cellulose, TAC), polymethyl ester, polyethylene terephthalate (Polyethylene Terephthalate, PET) and any combination thereof.

It is worth noting that in some embodiments of the present invention, there is a certain space distance between the light attenuating element 103 and the first light emitting module 101 in order not to affect the light of the first light emitting module 101 being guided out from the light emitting surface 101a. . In other words, the light attenuating element 103 is not in direct contact with the first light emitting module 101 . For example, in this embodiment, there is a certain space (air layer) between the first polarizer 110 of the light attenuating element 103 and the light guide element 106 of the first light emitting module 101, so that the two will not be in direct contact.

In addition, in order to increase the product reliability (reliability) of the light-attenuating element and prevent the first polarizer 110 from warping (waving) after assembly, in some embodiments of the present invention, the light-attenuating element can also be made of at least A multi-layer structure composed of two polarizers, and the light absorption axes of these polarizers are parallel to each other. For example, please refer to FIG. 2A , which is a schematic cross-sectional view of a backlight module 200 according to another embodiment of the present invention. The structure of the backlight module 200 is substantially similar to that of the backlight module 100 shown in FIG. between the module 102 and the first polarizer 110 (that is, the first polarizer 110 is located above the second polarizer 210 ). And the second polarizer 210 has a second light absorption axis X2 substantially parallel to the first light absorption axis X1 of the first polarizer 110 . In another embodiment of the present invention, the second polarizer 210 may be located between the first light emitting module 101 and the first polarizer 110 (that is, the second polarizer 210 is located above the first polarizer 110 ).

Please refer to FIG. 2B . FIG. 2B is an enlarged cross-sectional schematic diagram of a partial structure of a light attenuating element 203 shown in FIG. 2A . In this embodiment, the light attenuating element 203 is a double-layer structure composed of the first polarizer 110 , the second polarizer 210 and the adhesive layer 211 between the first polarizer 110 and the second polarizer 210 . Wherein, the second polarizer 210 includes a third base material layer 210a, a fourth base material layer 210b, and a polyvinyl alcohol layer 210c interposed between the third base material layer 210a and the fourth base material layer 210b. Materials constituting the third base material layer 210a and the fourth base material layer 210b may be the same or different. And the materials constituting the third base material layer 210a and the fourth base material layer 210b can be selected from triacetate cellulose, polymethyl ester, polyethylene terephthalate and any combination of the above. a group of people. The material of the adhesive layer 211 may be a transparent pressure sensitive adhesive (Pressure Sensitive Adhesive, PSA) or other possible transparent adhesive materials. Since the warping directions of the stress of the first polarizer 110 and the second polarizer 210 are opposite to each other to compensate for the deformation, the light attenuating element 203 with two polarizers facing each other is more deformed than the light attenuating element 103 with only a single polarizer Small.

In some embodiments of the present invention, the light attenuating element may further include at least one optical film located between the first polarizer 110 and the second polarizer 210 . For example, please refer to FIG. 3A and FIG. 3B . FIG. 3A is a schematic cross-sectional view of a backlight module 300 according to another embodiment of the present invention. FIG. 3B is an enlarged cross-sectional schematic diagram of a partial structure of a light attenuating element 303 shown in FIG. 3A . Wherein the structure of the backlight module 300 is substantially similar to the backlight module 200 shown in FIG. ), Brightness Enhancement Film (BEF), reflective polarized Brightness Enhancement Film (Dual Brightness Enhancement Film, DBEF) or an optical film 312 composed of any combination of the above, and the adhesive layer 211 and the first The polarizer 110 and the second polarizer 210 are combined.

It should be noted that, if the optical film 312 arranged between the first polarizer 110 and the second polarizer 210 is a reflective polarized light enhancement film, its light transmission axis T3 must be substantially the same as that of the first polarizer 110 and the second polarizer. The first light absorption axis X1 and the second light absorption axis X2 of the two polarizers 210 are parallel.

In some embodiments of the present invention, the light attenuating element may further include at least one optical film located between one of the first light emitting module 101 and the second light emitting module 102 and the light attenuating element. For example, please refer to FIG. 4A to FIG. 4C . FIG. 4A is a schematic cross-sectional view of a backlight module 400A according to yet another embodiment of the present invention. FIG. 4B is a schematic cross-sectional view of a backlight module 400B according to yet another embodiment of the present invention. FIG. 4C is an enlarged cross-sectional schematic diagram of a partial structure of a light attenuating element 403 shown in FIG. 4A and FIG. 4B . The structure of the backlight module 400A is generally similar to that of the backlight module 200 shown in FIG. 2A , the only difference is that the light attenuating element 403 includes at least one polarizer composed of a diffuser plate, a brightness enhancement film, and a reflective polarizer in addition to the first polarizer 110. The optical film 412 formed by the brightness enhancement film or any combination thereof is located between the second light-emitting module 102 and the first polarizer 110 (that is, the optical film 412 is disposed above the first polarizer 110 ). The structure of the backlight module 400B is also similar to that of the backlight module 400A, the only difference is that the configuration of the light attenuating element 403 is different from that of the backlight module 400A. In the backlight module 400B, the optical film 412 of the light attenuating element 403 is located between the first light-emitting module 101 and the first polarizer 110 (that is, the optical film 412 is disposed under the first polarizer 110 ).

In addition, in order to increase the light extraction rate of the second light-emitting module 102, it is preferable to arrange at least one diffuser plate 112, brightness-enhancing film 113, reflective polarizer The bright film 114 or the optical film 112 formed by any combination of the above (as shown in FIG. 1A , FIG. 2A , FIG. 3A , FIG. 4A and FIG. 4B ). In some embodiments of the present invention, at least one optical film (not shown) may also be arranged between the first light emitting module 101 and the light attenuating elements 103 , 203 and 303 . It is worth noting that the reflective polarizing brightness enhancement film 114 arranged between the first light emitting module 101 and the second light emitting module 102 has a light transmission axis T1 substantially in line with the first polarizing plate 110 and the second polarizing plate 210. The first light absorption axis X1 and the second light absorption axis X2 are parallel. If the optical film 412 is a reflective polarized brightness enhancement film, its light transmission axis T4 is substantially parallel to the first light absorption axis X1 and the second light absorption axis X2 .

If the above-mentioned backlight module, such as the backlight module 200 as an example, is integrated with a display panel, a display device 50 with switchable 2D/3D images can be formed. Please refer to FIG. 5 . FIG. 5 is a schematic cross-sectional view of a display device 50 according to an embodiment of the present invention. The display device 50 includes a display panel 51 and the backlight module 200 shown in FIG. 2A . The display panel 51 may be a liquid crystal display panel or other suitable display media. In this embodiment, the display panel 51 may be a liquid crystal display panel, including a liquid crystal layer 51a and substrates (not shown) respectively located on the upper and lower sides of the liquid crystal layer 51a, and a lower polarizer 51b and an upper polarizer opposite to each other. 51c. The lower polarizer 51b and the upper polarizer 51c respectively have a first polarization axis P1 and a second polarization axis P2 that are perpendicular to each other. The light-emitting surface 101a of the first light-emitting module 101 (that is, the first side 104c of the light guide plate) corresponds to the lower polarizer 51b of the display panel 51; The second light absorption axis X2 is substantially parallel to the first polarization axis P1 of the lower polarizer 51b.

When the display device 50 is to display a three-dimensional image, the light emitting unit 108 of the second light emitting module 102 can be turned off, and only the light emitting unit 105 of the first light emitting module 101 provides light. Most of the light L1a emitted by the light emitting unit 105, after entering the light guide plate 104, is guided by the light guide element 106, and passes through the light output surface 101a of the first light emitting module 101 (that is, the light guide plate The first side 104c) of the display panel 51 is directed to the display panel 51, and the left-eye image output by some pixels (not shown) in the display panel 51 is transmitted to the left eye of the user, and the other part of the pixels (not shown) on the display panel 51 ( Not shown) the output right eye image is transmitted to the user's right eye, so that the user's two eyes can respectively receive different images with binocular parallax (binocular parallax), so that the user does not need to wear auxiliary glasses Stereoscopic images can be perceived with the naked eye.

Another part of the light L1b emitted by the light emitting unit 105 enters the light guide plate 104 , is guided out by the second side surface 104 d of the light guide plate 104 , and goes to the light attenuating element 203 . Since the light L1b is non-polarized light, only the polarized light L1b1 parallel to the first light absorption axis X1 and the second light absorption axis X2 of the first polarizer 110 and the second polarizer 210 can pass through the light attenuating element 203 . For example, in this embodiment, the light transmittance of the first polarizer 110 and the second polarizer 210 of the attenuation element 203 is substantially between 40% and 50%. Therefore, the light intensity of the polarized light L1b1 that passes through the light attenuating element 203 and then radiates to the second light emitting module 102 will be attenuated by about 50%. The polarized light L1b1 directed to the second light-emitting module 102, after being reflected and scattered by the diffuser plate 112, the brightness enhancement film 113, the reflective polarized brightness enhancement film 114, and the light guide plate 107 and the reflection sheet 109 of the second light-emitting module 102 , the polarization state of most of the light L1b1 will change. Therefore, when incident on the light attenuating element 203 again, only part of the polarized light L1b2 that is still parallel to the first light absorption axis X1 and the second light absorption axis X2 of the first polarizer 110 and the second polarizer 210 can pass through the light attenuation Element 203. In other words, the light intensity will be at least again attenuated by approximately 50%. Therefore, the configuration of the light attenuating element 203 can greatly reduce the intensity of the light L1b emitted by the light emitting unit 105 and reflected by the second light emitting module 102 through the light emitting surface 101a. Further prevent the light L1b that is not directly emitted from the light-emitting surface 101a of the first light-emitting module 101 from producing unexpected bright and dark images on the display panel 51, and produce crosstalk with the stereoscopic image directly passing through the light-emitting surface 101a, so as to improve The effect of the stereoscopic image display quality of the display device 50 .

In some embodiments of the present invention, it is preferable to perform a surface treatment on the light-emitting surface 101a of the light-attenuating element 203 facing the first light-emitting module 101 (that is, the upper surface of the first base material layer 110a), so that At least one surface treatment structure 504 is formed on the surface 101a. The surface treatment structure 504 may include at least one protrusion, at least one protrusion, at least one groove, at least one opening, at least one depression or any combination thereof. The light L1b scattered by the surface treatment structure 504 can prevent the light L1b directed to the second light-emitting module 102 from being directly reflected by the light-attenuating element 203 and passing through the light-emitting surface 101a to produce unexpected bright and dark interlacing on the display panel 51 Align the images to reduce the occurrence of moiré. In other embodiments of the present invention, the above-mentioned surface treatment structure 504 ( not shown).

When the display device 50 is to display a two-dimensional image, the light emitting unit 105 of the first light emitting module 101 can be turned off, and only the light emitting unit 108 of the second light emitting module 102 can provide light. After the light L2 emitted by the light emitting unit 108 enters the light guide plate 107, most of the light L2a directly passes through the diffuser plate 112, the brightness enhancement film 113, the reflective polarizing brightness enhancement film 114, the light attenuation element 203 and the first light emitting module 101 The other part of the light L2b is first reflected by the reflector 109, and then passes through the second light emitting module 102, the diffuser plate 112, the brightness enhancement film 113, the reflective polarizing brightness enhancement film 114, the light attenuation element 203 and the first light emitting module 101 , and then led out from the light-emitting surface 101a (that is, the first side 104c) of the first light-emitting module 101 to form a polarized light L2c with a single polarization state, which transmits the planar image output by the pixels (not shown) in the display panel 51 to the user's eyes.

Because, the first light absorption axis X1 and the second light absorption axis X2 of the first polarizer 110 and the second polarizer 210 are substantially parallel to the first polarization axis P1 of the lower polarizer 51 b. Therefore, almost all (substantially between 90% and 98%) of the polarized light L2c will pass through the lower polarizer 51b. In other words, the configuration of the light attenuating element 203 has little influence on the actual light extraction rate of the second light emitting module 102 . In addition, in order to complement the light extraction rate of the second light emitting module 102 , in some embodiments of the present invention, at least a part of the light emitting units 105 of the first light emitting module 101 may also be turned on when the display device 50 displays a planar image.

Please refer to FIG. 6 . FIG. 6 is a schematic cross-sectional view of a display device 60 according to another embodiment of the present invention. Since the display device 60 has a similar structure to the display device 50 shown in FIG. 5 , the same component structures are not repeated here. The difference between the display device 60 and the display device 50 lies in the structure and configuration of the light attenuating element 603 . In this embodiment, the display device 60 includes a display panel 51 and a backlight module 600 . The backlight module 600 includes a first light emitting module 101 , a reflective sheet 609 , a second light emitting module 102 and a light attenuating element 603 . The first light emitting module 101 has a light emitting surface 101 a facing the display panel 51 ; the reflective sheet 609 is located on the opposite side of the light emitting surface 101 a. The second light emitting module 102 is located between the first light emitting module 101 and the reflection sheet 609 . The light attenuating element 603 includes a polarizer 610 and a retardation plate 611 . The polarizer 610 has a light absorption axis X6 and is located between the second light emitting module 102 and the reflection sheet 609 . The retardation plate 611 is located between the polarizer 610 and the reflection sheet 609 . In some embodiments of the present invention, the reflective sheet 609 is preferably a mirror image reflective sheet. The retardation plate 611 may be a quarter (λ/4) wave plate.

When the display device 60 is to display a three-dimensional image, the light emitting unit 108 of the second light emitting module 102 can be turned off, and only the light emitting unit 105 of the first light emitting module can provide light. Most of the light L1a emitted by the light emitting unit 105, after entering the light guide plate 104, is guided by the light guide element 106, and passes through the light output surface 101a of the first light emitting module 101 (that is, the light guide plate The first side 104c) of the display panel 51 is directed to the display panel 51, and the left-eye image output by some pixels (not shown) in the display panel 51 is transmitted to the left eye of the user, and the other part of the pixels (not shown) on the display panel 51 ( (not shown) the output right eye image is transmitted to the user's right eye, so that the user's two eyes can receive different images with binocular parallax, so that the user can use the naked eye without wearing auxiliary glasses Perceive stereoscopic images.

Another part of the light L1b emitted by the light emitting unit 105 enters the light guide plate 104 , is guided by the second side surface 104 d of the light guide plate 104 , goes to the second light emitting module 102 and passes through the second light emitting module 102 and the attenuation element 603 . Since the light L1b is non-polarized light, only the light absorption axis X6 of the parallel polarizing plate 610 can pass through the light attenuating element 603 and enter the phase difference plate 611 . In this embodiment, the light intensity of the polarized light L1b1 passing through the light attenuating element 603 will be attenuated by about 50%. The polarized light L1b1 incident on the retardation plate 611 will generate a phase difference of a quarter wavelength (λ/4) after passing through the retardation plate 611 . After the polarized light L1b1 is mirror-reflected by the reflective sheet 609, it cannot pass through the second light emitting module 102, the diffusion plate 112, the brightness enhancement film 113, the reflective polarization brightness enhancement film 114 and the The first light-emitting module 101 is led out from the light-emitting surface 101a. Therefore, there will be no unexpected bright and dark alternately arranged images on the display panel 51 , which can prevent image crosstalk in the stereoscopic images of the display device 60 and achieve the effect of improving the display quality of the stereoscopic images of the display device 60 .

When the display device 60 is to display a two-dimensional image, the light-emitting unit 108 of the first light-emitting module 101 can be turned off, and only the light-emitting unit 105 of the second light-emitting module can provide light. After the light L2 emitted by the light emitting unit 105 enters the light guide plate 107, most of the light L2a directly passes through the diffusion plate 112, the brightness enhancement film 113, the reflective polarizing brightness enhancement film 114 and the first light emitting module 101, and the display panel The two-dimensional images output by the pixels (not shown) in 51 are sent to the eyes of the user. Another part of the light L2b emitted by the light emitting unit 105 enters the light guide plate 107, first passes through the light attenuating element 603, is mirror-reflected by the reflective sheet 609, and then no longer passes through the second light emitting module 102 and the first light emitting module 101. , derived from the light-emitting surface 101a. In some embodiments of the present invention, in order to supplement the light extraction rate of the second light emitting module 102 , at least a part of the light emitting units 105 of the first light emitting module 101 can be turned on when the display device 50 displays a two-dimensional image.

According to the above, the embodiments of the present invention provide a 2D/3D switchable display device and a backlight module thereof. In some embodiments of the present invention, the backlight module of the display device at least includes a first light-emitting module and a second light-emitting module arranged parallel to each other, and at least Two display modes. Wherein, the first light-emitting module has a light-emitting surface, and a light-attenuating element including at least one absorbing polarizer is arranged on the opposite side of the light-emitting surface to prevent the light emitted by the first light-emitting module from entering the second light-emitting module. A part of the light is reflected by the second light-emitting module to produce unexpected bright and dark moirés, thereby preventing crosstalk between the part of the light and the light emitted by the first light-emitting module and directly passing through the light-emitting surface. The display quality when the display device adopts the first light-emitting module can be improved without affecting the display quality when switching to the second display mode.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection should be defined by the claims.

Claims (18)

1. a kind of backlight module (back light module), including：

One first light emitting module (light emitting module) has a light-emitting surface；

One second light emitting module, positioned at the opposite side of the light-emitting surface；And

One optical attenuator component (attenuator), between first light emitting module and second light emitting module；

Wherein, which includes one first polarizer, which has one first light absorption axis；

Wherein the optical attenuator component has a surface treatments, and the one of first light emitting module is faced positioned at the optical attenuator component On surface；The surface treatments are selected from by an at least protrusion (protrusions), at least an at least raised line, a ditch Slot (slots), at least one opening (openings), an at least recessed portion (recesses) and above-mentioned any combination are formed A group.

2. backlight module as described in claim 1, which is characterized in that first light emitting module includes：

One light guide plate has an at least incidence surface and a first side and a second side relative to each other；

An at least luminescence unit, the adjacent incidence surface；And

Multiple light-guide devices are arranged at least one of the first side and the second side.

3. backlight module as described in claim 1, which is characterized in that first polarizer, including a first base material layer, one Two substrate layers and the polarizing layer being located between the first base material layer and second substrate layer；The first base material layer and this The material of two substrate layers is Triafol T (Triacetate Cellulose, TAC), polyacids methyl esters (Polymethylmethacrylate, PMMA), polyethylene terephthalate (Polyethylene Terephthalate, ) and the group that is formed of above-mentioned any combination PET；The polarisation layer material is polyvinyl alcohol (Poly-Vinyl Alcohol, PVA).

4. backlight module as described in claim 1, which is characterized in that the optical attenuator component is further included with one second light absorption One second polarizer of axis, positioned at one of both first light emitting module and second light emitting module and first polarizer Between；And the second light absorption axis is substantially parallel to the first light absorption axis.

5. backlight module as described in claim 1, which is characterized in that the optical attenuator component further includes an at least optical diaphragm, Positioned at one of both first light emitting module and second light emitting module between first polarizer；An at least optics Diaphragm is to be selected to be made of a diffuser plate, a brightness enhancement film, a dual brightness enhancement film and above-mentioned any combination One group.

6. backlight module as claimed in claim 5, which is characterized in that an at least optical diaphragm is a dual brightness enhancement Film, and it is substantially parallel to the first light absorption axis with a smooth penetrating shaft.

7. a kind of display device, including：

One display panel including polarizer on polarizer once relative to each other and one, and is respectively provided with mutually orthogonal 1 One polarizing axis and one second polarizing axis；And

One backlight module, including：

One first light emitting module has a light-emitting surface, in face of the lower polarizer；

One second light emitting module, positioned at the opposite side of the light-emitting surface；And

One optical attenuator component between first light emitting module and second light emitting module, including one first polarizer, has One first light absorption axis, essence are parallel with first polarizing axis of the lower polarizer；

Wherein the optical attenuator component has a surface treatments, and the one of first light emitting module is faced positioned at the optical attenuator component On surface；The surface treatments be selected from by an at least protrusion, an at least raised line, an at least groove, at least one opening, The group that an at least recessed portion and above-mentioned any combination are formed.

8. display device as claimed in claim 7, which is characterized in that first light emitting module includes：

One light guide plate has an at least incidence surface and a first side and a second side relative to each other；

An at least luminescence unit, the adjacent incidence surface；And

Multiple light-guide devices are arranged at least one of the first side and the second side.

9. display device as claimed in claim 7, which is characterized in that first polarizer includes a first base material layer, one the Two substrate layers and the polarizing layer being located between the first base material layer and second substrate layer；The first base material layer and this The material of two substrate layers is Triafol T, polyacids methyl esters, polyethylene terephthalate and above-mentioned any combination institute One group of composition；The material of the polarizing layer is polyvinyl alcohol.

10. display device as claimed in claim 7, which is characterized in that the optical attenuator component is further included to be inhaled with one second light One second polarizer of axis is received, positioned at one of both first light emitting module and second light emitting module and first polarisation Between plate；And the second light absorption axis is substantially parallel to the first light absorption axis.

11. display device as claimed in claim 7, which is characterized in that the optical attenuator component further includes an at least optical diaphragm, Positioned at one of both first light emitting module and second light emitting module between first polarizer；An at least optics Diaphragm is to be selected to be made of a diffuser plate, a brightness enhancement film, a dual brightness enhancement film and above-mentioned any combination One group.

12. display device as claimed in claim 11, which is characterized in that an at least optical diaphragm is that a reflecting type polarizing increases Bright film, and it is substantially parallel to the first light absorption axis with a smooth penetrating shaft.

13. a kind of backlight module, including：

One first light emitting module has a light-emitting surface；

One reflector plate, positioned at the opposite side of the light-emitting surface；

One second light emitting module, between first light emitting module and the reflector plate；And

One optical attenuator component, including：

One polarizer has a light absorption axis, and between second light emitting module and the reflector plate；

And

One polarizer, between the polarizer and the reflector plate.

14. backlight module as claimed in claim 13, which is characterized in that first light emitting module includes：

One light guide plate has an at least incidence surface and a first side and a second side relative to each other；

An at least luminescence unit, the adjacent incidence surface；And

Multiple light-guide devices are arranged at least one of the first side and the second side.

15. backlight module as claimed in claim 13 further includes an at least optical diaphragm, positioned at first light emitting module and it is somebody's turn to do Between second light emitting module；An at least optical diaphragm is selected from by a diffuser plate, a brightness enhancement film, a dual brightness enhancement The group that film and above-mentioned any combination are formed.

16. a kind of display device, including：

One display panel；And

One backlight module, including：

One first light emitting module has a light-emitting surface, in face of the display panel；

One reflector plate, positioned at the opposite side of the light-emitting surface；

One second light emitting module, between first light emitting module and the reflector plate；And

One optical attenuator component, including：

One polarizer has a light absorption axis, and between second light emitting module and the reflector plate；And

One polarizer, between the polarizer and the reflector plate.

17. display device as claimed in claim 16, which is characterized in that first light emitting module includes：

One light guide plate has an at least incidence surface and a first side and a second side relative to each other；

An at least luminescence unit, the adjacent incidence surface；And

Multiple light-guide devices are arranged at least one of the first side and the second side.

18. display device as claimed in claim 16 further includes an at least optical diaphragm, positioned at first light emitting module and it is somebody's turn to do Between second light emitting module；An at least optical diaphragm is selected from by a diffuser plate, a brightness enhancement film, a dual brightness enhancement The group that film and above-mentioned any combination are formed.