TWI622835B - Backlight module and display device - Google Patents

Abstract

A backlight module includes two light guide plates, two light emitting modules and a controller. The light guide plates each have a light incident surface and a light exit surface. The light guide plates are arranged side by side so that the light exit surfaces are coplanar. Each of the light emitting modules is configured to provide a first type of light and a second type of light to a light incident surface of the corresponding light guide plate. The first type of light has a first triplet state. The second type of light has a second triplet state. The second triplet state is different from the first triplet state. The controller is configured to sequentially provide the first type of light and the second type of light by driving any of the light emitting modules at different times.

Description

Backlight module and display device

The invention relates to a backlight module and a display device.

Using human two-eye parallax, the conventional stereoscopic display device achieves three-dimensional display by providing different images of the two eyes of the viewer. According to the difference in the way of achieving different images, the stereoscopic display device includes a polarization type, a red-blue type or a wavelength multiplexing type.

Among them, the wavelength multiplexed stereoscopic display device, as the name suggests, is to provide viewers with images of different wavelength ranges to achieve three-dimensional display. Since the color image is mostly mixed with the three primary colors (R (red), G (green), B (blue)), the conventional wavelength multiplexed stereo display device has two sets of three primary colors. R1, G1, B1 and R2, G2, and B2 distinguish left and right eye images.

At present, a wavelength multiplexed stereoscopic display device using a direct back-lit backlight technology has been developed which provides two sets of three primary colors with two sets of light sources uniformly distributed. However, due to the use of direct-lit backlight technology, such conventional stereoscopic display devices not only have a large housing depth, but also the number of light sources used is excessive. Therefore, how to reduce the size of the stereoscopic display device and reduce the number of light sources used is a common goal of the industry.

In view of the above, it is an object of the present invention to provide a backlight module that can reduce the overall size and reduce the number of light sources used, and a display device using the same.

In order to achieve the above object, a backlight module includes two light guide plates, two light emitting modules, and a controller according to an embodiment of the present invention. The light guide plates each have a light incident surface and a light exit surface. The light guide plates are arranged side by side so that the light exit surfaces are coplanar. Each of the light emitting modules is configured to provide a first type of light and a second type of light to a light incident surface of the corresponding light guide plate. The first type of light has a first triplet state. The second type of light has a second triplet state. The second triplet state is different from the first triplet state. The controller is configured to sequentially provide the first type of light and the second type of light by driving any of the light emitting modules at different times.

In one or more embodiments of the present invention, each of the foregoing light emitting modules includes a first light emitter, a second light emitter, a first filter, a second filter, and a light guiding component. The first filter has a first light reflection spectrum. The second filter has a second light reflection spectrum. The light guiding component is configured to guide the light emitted by the first light emitter and the second light emitter to the first filter and the second filter, respectively, thereby obtaining the first type of light and the second type of light, respectively. . The light guiding component is further configured to guide the first type of light and the second type of light to the light incident surface of the corresponding light guide plate.

In one or more embodiments of the present invention, the light guiding component includes a first total reflection 稜鏡 and a second total reflection 稜鏡. First total reflection rib The mirror has a first surface, a second surface, and a third surface that are sequentially adjacent. The second total reflection 稜鏡 has a fourth surface, a fifth surface, and a sixth surface that are sequentially adjacent. The first surface is opposite the fourth surface. The second surface is opposite the fifth surface. The third surface faces the sixth surface. The first light emitter and the second light emitter emit light toward the first surface. The first filter and the second filter are respectively disposed on the fourth surface and the second surface.

In one or more embodiments of the present invention, the light guiding assembly further includes a collimating lens. The collimating lens is configured to convert the light emitted by the first light emitter and the second light emitter into a first collimated light and a second collimated light, respectively, and each of the first collimated light and the second collimated light Do not differ from the angle of incidence of the third surface.

In one or more embodiments of the present invention, the light guiding component further includes a light guiding component. The light guiding element is optically coupled between the fifth surface and the light incident surface of the corresponding light guide plate. The light guiding element is substantially opposite to the light incident surface of the corresponding light guide plate, and faces the fifth surface in a direction substantially parallel to the corresponding light incident surface.

In one or more embodiments of the present invention, the first light emitter and the second light emitter are substantially side by side in a first direction and each include a plurality of light sources. The light sources of either the first light emitter and the second light emitter are substantially aligned along the second direction.

In one or more embodiments of the present invention, the controller is configured to drive the two lighting modules to provide the first type of light and the second type of light in four time intervals in a working cycle.

In one or more embodiments of the present invention, the above-described duty cycle has six time intervals in sequence. The controller is configured to provide the first type of light and the second type of light in one of the first time interval and the fourth time interval of the foregoing time interval, and configured to be the third of the foregoing time intervals The other of the time interval and the sixth time interval driving the illumination module provides the first type of light and the second type of light.

In order to achieve the above object, in accordance with an embodiment of the present invention, a display device includes the foregoing backlight module and a liquid crystal display panel. Each of the light guide plates also has a light emitting surface. The liquid crystal display panel has a light receiving surface. The two light-emitting surfaces of the two light guide plates respectively face two portions of the light-receiving surface.

In one or more embodiments of the present invention, the liquid crystal display panel has a vertical Sync scan direction. The two light guide plates are arranged substantially in the synchronous scanning direction of the signal.

In summary, the backlight module of the present invention uses two illumination modules to respectively illuminate toward the sides of the two light guides, and the controller of the backlight module can drive the two light emitters in each of the illumination modules to be different. The time interval provides two types of light, respectively. Further, the backlight module of the present invention can drive the four groups of light emitters to be turned on and off according to the timing of the signal synchronous scanning direction of the liquid crystal display panel, so that the display device of the present invention can be sideways. In the backlight architecture, a display technology that simultaneously uses time multiplexing and wavelength multiplexing is realized. Moreover, since the backlight module of the present invention belongs to a side-lit backlight architecture, the display device of the present invention can effectively reduce the overall size and reduce the number of light sources used compared to the conventional stereoscopic display device using the direct-lit backlight technology. .

The above description is only for explaining the problems to be solved by the present invention, the technical means for solving the problems, the effects thereof, and the like, and the specific details of the present invention will be described in detail in the following embodiments and related drawings.

The embodiments of the present invention are disclosed in the following drawings, and the details of However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not necessary. In addition, some of the conventional structures and elements are shown in the drawings in a simplified schematic manner in order to simplify the drawings.

Please refer to FIG. 1 , which is a perspective view of a display device 100 according to an embodiment of the present invention. As shown in FIG. 1, the display device 100 includes a backlight module 200 and a liquid crystal display panel 300. The backlight module 200 includes two light guide plates 210 , two light emitting modules 220 , and a controller 230 . The structure, function, and connection relationship between the various components of the backlight module 200 will be described in detail below.

Please refer to Figure 2 and Figure 3. FIG. 2 is a partial perspective view of a backlight module 200 according to an embodiment of the present invention. Fig. 3 is a partial perspective view showing a part of the elements in Fig. 2. As shown in FIGS. 1 to 3 , the two light guide plates 210 each have a light incident surface 211 and a light exit surface 212 . The two light guide plates 210 are arranged side by side so that the two light exiting surfaces 212 are coplanar. The liquid crystal display panel 300 has a light receiving surface 310. The two light-emitting surfaces 212 of the two light guide plates 210 respectively face two portions of the light-receiving surface 310.

Each of the light-emitting modules 220 is configured to provide a first type of light A' and a second type of light B' (indicated in FIG. 3) to the light-incident surface 211 of the corresponding light guide plate 210. The first type of ray A' has a first triplet. The second type of light B' has a second triplet state. The second triplet state is different from the first triplet state. For example, the first triplet of the first type of light A' corresponds to a set of three primary colors R1, G1, B1, and the second triplet of the second type of light B' corresponds to another set of three primary colors R2, G2, respectively. B2.

Specifically, each of the light emitting modules 220 includes a first light emitter 221, a second light emitter 222, a first filter 223, a second filter 224, and a light guiding component 225. Please refer to FIG. 4 , which is a reflectance-wavelength diagram of the first filter 223 and the second filter 224 according to an embodiment of the present invention. As can be seen from the reflectance-wavelength curves C1, C2 shown in FIG. 4, the first filter 223 has a first light reflection spectrum, and the second filter 224 has a second light reflection spectrum, and the first light reflection spectrum Deviation from the second light reflection spectrum. The light guiding component 225 is configured to guide the light emitted by the first light emitter 221 and the second light emitter 222 to the first filter 223 and the second filter 224, respectively, thereby obtaining the first type Light A' and second type of light B', wherein the first triplet of the first type of light A' substantially matches the first light reflectance spectrum, and the second triplet of the second type of light B' is substantially The first light reflection spectrum is matched. The light guiding assembly 225 is further configured to guide the first type of light A' and the second type of light B' to the light incident surface 211 of the corresponding light guide plate 210.

Further, in order to achieve the foregoing, the light emitted by the first light emitter 221 and the second light emitter 222 is respectively guided to the first filter 223 and the second filter 224 and the first type to be generated. For the purpose of guiding the light A' and the second type of light B' to the light incident surface 211 of the corresponding light guide plate 210, in the present embodiment, the light guiding assembly 225 includes a first total reflection pupil 225a and a second total reflection.稜鏡 225b. As shown in FIG. 3, the first total reflection pupil 225a has a first surface 225a1, a second surface 225a2, and a third surface 225a3 which are sequentially adjacent. The second total reflection 稜鏡225b has a fourth surface 225b1, a fifth surface 225b2, and a sixth surface 225b3 that are sequentially adjacent. The first surface 225a1 is opposite the fourth surface 225b1. The second surface 22582 is opposite the fifth surface 225b2. The third surface 225a3 faces the sixth surface 225b3. The first light emitter 221 and the second light emitter 222 emit light toward the first surface 225a1. The first filter 223 and the second filter 224 are respectively disposed on the fourth surface 225b1 and the second surface 225a2.

As shown in FIG. 2, the first light emitter 221 and the second light emitter 222 are substantially side by side in the first direction D1, and each includes a plurality of light sources (not shown). These light sources are, for example, light emitting diodes. First light emitter 221 and second light The light sources in any of the emitters 222 are arranged substantially along the second direction D2. In the present embodiment, the first direction D1 and the second direction D2 are substantially perpendicular to each other, but the invention is not limited thereto. The light guiding assembly 225 also includes a plurality of focusing lenses 225c and a collimating lens 225d. Each focusing lens 225c is configured to focus the light emitted by the corresponding source to reduce the beam angle of the light emitted by the source. The collimating lens 225d is optically coupled between any of the focusing lenses 225c and the first total reflection pupil 225a, and is configured to convert the light emitted by the first light emitter 221 and the second light emitter 222 into a first standard The straight ray A and the second collimated ray B are different from each other with respect to the incident angle of the first collimated ray A and the second collimated ray B with respect to the third surface 225a3.

For example, in some embodiments, the angle between the first surface 225a1 and the second surface 225a2 is 90 degrees, and the angle between the first surface 225a1 and the third surface 225a3 and the second surface 225a2 and the third surface The angle between 225a3 is 45 degrees. In some embodiments, the angle between the fourth surface 225b1 and the fifth surface 225b2 is 90 degrees, and the angle between the fourth surface 225b1 and the sixth surface 225b3 and between the fifth surface 225b2 and the sixth surface 225b3 The angle is 45 degrees. In some embodiments, the third surface 225a3 and the sixth surface 225b3 are parallel to each other. As shown in FIG. 3, since the collimating lens 225d is disposed such that the incident angle of the first collimated ray A with respect to the third surface 225a3 is small, the first total reflection 稜鏡 225a and the second total reflection 稜鏡225b, in accordance with the foregoing configuration, the first collimated ray A will sequentially pass through the third surface 225a3, the sixth surface 225b3 and the fourth surface 225b1 to reach the first filter 223, and be filtered by the first filter. The first collimated ray A reflected by the 223 is converted into the first type of ray A' and sequentially passes through the fourth surface. 225b1 is reflected by sixth surface 225b3 and finally exits second total reflection 稜鏡 225b by fifth surface 225b2. In contrast, since the collimating lens 225d is configured such that the incident angle of the second collimated ray B with respect to the third surface 225a3 is large, the first total reflection 稜鏡 225a and the second total reflection 稜鏡 225b are in accordance with the foregoing structure. In the case of the configuration, the second collimated light B is sequentially reflected by the third surface 225a3 and passes through the second surface 225a2 to reach the second filter 224, and is reflected by the second filter 224. The straight ray B will be converted into a second type of ray B' and sequentially passed through the second surface 225a2, the third surface 225a3 and the sixth surface 225b3, and finally exits the second total reflection 稜鏡 225b by the fifth surface 225b2.

As shown in FIG. 2, by arranging the first total reflection pupil 225a and the second total reflection pupil 225b in accordance with the foregoing structure, the first filter 223 and the second filter 224 do not have to be parallel and side by side. Settings. For example, the second filter 224 does not have to be parallel to the first filter 223 and arranged side by side in the first direction D1, so the first light emitter 221 and the second light emitter 222 are in the first direction D1. The distance on the upper side can be reduced, thereby effectively reducing the size of the light-emitting module 220.

As shown in FIG. 2, the light guiding assembly 225 further includes a diverging lens 225e and a light guiding element 225f. The diverging lens 225e is optically coupled between the fifth surface 225b2 of the second total reflection pupil 225b and the light guiding element 225f, and is configured to diverge the first type of light A' and the second type of light B'. The light guiding element 225f is optically coupled between the fifth surface 225b2 (via the diverging lens 225e) and the light incident surface 211 of the corresponding light guide plate 210. The light guiding element 225f substantially faces the light incident surface 211 of the corresponding light guide plate 210, and faces the fifth surface 225b2 in a direction substantially parallel to the corresponding light incident surface 211. By using the light guiding element 225f, the size of the backlight module 200 in the direction perpendicular to the light incident surface 211 of the light guide plate 210 can be reduced, thereby facilitating the narrow bezel design of the display device 100.

As shown in FIG. 1, the controller 230 of the backlight module 200 is configured to sequentially supply the first type of light A' and the second type of light B' by driving any of the light emitting modules 220 at different times. For example, the controller 230 is configured to drive the two lighting modules 220 to provide the first type of light A' and the second type of light B' in four time intervals in a working cycle.

Specifically, please refer to FIG. 5A to FIG. 5F , which illustrate the operation states of the backlight module 200 and the liquid crystal display panel 300 in six time intervals in a working cycle, respectively. The liquid crystal display panel 300 has a vertical Sync scanning direction as indicated by the hollow arrows in FIGS. 5A to 5F. The two light guide plates 210 are arranged substantially in the direction of the signal synchronous scanning. As shown in FIG. 5A, during the first time interval, the signal is synchronously scanned on the upper half of the liquid crystal display panel 300 (corresponding to the upper light guide plate 210), and the controller 230 is configured to drive the lower light guide plate 210. The light emitting module 220 provides a first type of light A', such that the lower light guide 210 supplies the surface light source of the first type of light A' to the lower half of the liquid crystal display panel 300. As shown in FIG. 5B, during the second time interval, the signal is synchronously scanned in the center of the liquid crystal display panel 300 (corresponding to the transition region between the two light guide plates 210), and the controller 230 does not drive any of the light emitting modules 220. . As shown in FIG. 5C, during the third time interval, the signal is synchronously scanned in the lower half of the liquid crystal display panel 300 (corresponding to the lower light guide plate 210), and the controller 230 is configured to drive the upper light guide plate 210. The light emitting module 220 provides a first type of light A', such that the upper light guide plate 210 supplies the surface light source of the first type of light A' to the upper half of the liquid crystal display panel 300. As shown in FIG. 5D, during the fourth time interval, the signal is synchronously scanned on the upper half of the liquid crystal display panel 300 (corresponding to the upper light guide plate 210), and the controller 230 is configured to drive the lower light guide plate 210. The light emitting module 220 provides a second type of light B', such that the lower light guide plate 210 supplies the surface light source of the second type of light B' to the lower half of the liquid crystal display panel 300. As shown in FIG. 5E, during the fifth time interval, the signal is synchronously scanned in the center of the liquid crystal display panel 300 (corresponding to the transition region between the two light guide plates 210), and the controller 230 does not drive any of the light emitting modules 220. . As shown in FIG. 5F, during the sixth time interval, the signal is synchronously scanned in the lower half of the liquid crystal display panel 300 (corresponding to the lower light guide plate 210), and the controller 230 is configured to drive the upper light guide plate 210. The light emitting module 220 provides a second type of light B', such that the upper light guide plate 210 supplies the surface light source of the second type of light B' to the upper half of the liquid crystal display panel 300.

From the above detailed description of the specific embodiments of the present invention, it can be clearly seen that the backlight module of the present invention uses two light-emitting modules to respectively illuminate toward the sides of the two light guide plates, and the controller of the backlight module can be Driving two light emitters in each lighting module provides two types of light respectively in different time intervals. Further, the backlight module of the present invention can drive the four groups of light emitters to be turned on and off according to the timing of the signal synchronous scanning direction of the liquid crystal display panel, so that the display device of the present invention can be sideways. In the backlight architecture, a display technology that simultaneously uses time multiplexing and wavelength multiplexing is realized. Moreover, since the backlight module of the present invention belongs to a side-lit backlight architecture, the display device of the present invention can effectively reduce the overall size and reduce the number of light sources used compared to the conventional stereoscopic display device using the direct-lit backlight technology. .

The present invention has been disclosed in the above embodiments, and is not intended to limit the scope of the present invention, and the invention may be modified and modified in various ways without departing from the spirit and scope of the invention. The scope is subject to the definition of the scope of the patent application.

100‧‧‧ display device

200‧‧‧Backlight module

210‧‧‧Light guide plate

211‧‧‧Into the glossy surface

212‧‧‧Glossy surface

220‧‧‧Lighting module

221‧‧‧First light emitter

222‧‧‧Second light emitter

223‧‧‧first filter

224‧‧‧second filter

225‧‧‧Light guiding components

225a‧‧‧First Total Reflection 稜鏡

225a1‧‧‧ first surface

225a2‧‧‧ second surface

225a3‧‧‧ third surface

225b‧‧‧Second Total Reflection

225b1‧‧‧ fourth surface

225b2‧‧‧ fifth surface

225b3‧‧‧ sixth surface

225c‧‧ ‧focus lens

225d‧‧‧ collimating lens

225e‧‧‧Diffuse lens

225f‧‧‧Light guiding element

230‧‧‧ Controller

300‧‧‧LCD panel

310‧‧‧Glossy surface

A‧‧‧First collimated light

B‧‧‧Second collimated light

A’‧‧‧The first type of light

B’‧‧‧Second light

C1, C2‧‧‧ reflectance-wavelength curve

D1‧‧‧ first direction

D2‧‧‧ second direction

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; FIG. 2 is a partial perspective view of a backlight module according to an embodiment of the present invention. Fig. 3 is a partial perspective view showing a part of the elements in Fig. 2. 4 is a graph showing a reflectance-wavelength diagram of a first filter and a second filter according to an embodiment of the present invention. 5A to 5F are diagrams showing the operation states of the backlight module and the liquid crystal display panel in six time intervals in a working cycle, respectively.

Claims (8)

A backlight module includes: two light guide plates, each having a light-incident surface and a light-emitting surface, wherein the light guide plates are arranged side by side to make the two light-emitting surfaces coplanar; two light-emitting modules, each of the light-emitting modules The first type of light has a first triplet state, and the second type of light has a second color. The first type of light has a first light state. a triplet state, wherein the second triplet state is different from the first triplet state, each of the light emitting modules comprising: a first light emitter; a second light emitter; a first filter, Having a first light reflecting spectrum; a second filter having a second light reflecting spectrum; and a light guiding component configured to emit light from the first light emitter and the second light emitter Leading to the first filter and the second filter respectively to obtain the first type of light and the second type of light, respectively, the light guiding component is further configured to: the first type of light and the first Two kinds of light are guided to the corresponding light incident surface of the light guide plate; and one The device is configured to non-simultaneously drive any of the plurality of light-emitting modules to sequentially provide the first type of light and the second type of light, wherein the light guiding component comprises: a first total reflection, having a sequence Adjacent one of the first surface, a second surface, and a third surface; and a second total reflection 稜鏡 having a fourth table in sequence a surface, a fifth surface, and a sixth surface, wherein the first surface is opposite to the fourth surface, the second surface is opposite to the fifth surface, and the third surface is opposite to the sixth surface Facing, wherein the first light emitter and the second light emitter emit light toward the first surface, and the first filter and the second filter are respectively disposed on the fourth surface and the second surface . The backlight module of claim 1, wherein the light guiding component further comprises: a collimating lens configured to convert the light emitted by the first light emitter and the second light emitter into one The first collimated light and the second collimated light illuminate, and the incident angles of the first collimated ray and the second collimated ray are different from each other with respect to the third surface. The backlight module of claim 1, wherein the light guiding component further comprises: a light guiding component coupled between the fifth surface and the corresponding light incident surface of the light guiding plate, wherein the light guiding component The light guiding element is substantially opposite to the light incident surface of the corresponding light guide plate, and is opposite to the fifth surface in a direction substantially parallel to the corresponding light incident surface. The backlight module of claim 1, wherein the first light emitter and the second light emitter are substantially side by side in a first direction, and each comprises a plurality of light sources, and the first light emission The light sources of any of the second light emitters are arranged substantially along a second direction. The backlight module of claim 1, wherein the controller is configured to drive the two illumination modules to provide the first type of light and the second type of light in four time intervals in a working cycle. The backlight module of claim 5, wherein the duty cycle has six time intervals in sequence, and the controller is configured to select one of the first time interval and the fourth time interval in the time intervals. Driving one of the light-emitting modules to provide the first type of light and the second type of light, and configured to drive the light-emitting modules in one of the third time interval and a sixth time interval of the time intervals The other of the first type of light provides the first type of light and the second type of light. A display device, comprising: a backlight module according to any one of claims 1 to 6; and a liquid crystal display panel having a light receiving surface, wherein the two light emitting surfaces of the two light guiding plates respectively face the light receiving surface Two parts of the face. The display device of claim 7, wherein the liquid crystal display panel has a signal synchronous scanning direction, and the two light guide plates are arranged substantially along the synchronous scanning direction of the signal.