Backlight module and liquid crystal display device

The present invention discloses a backlight module, which includes: a backplane, which has a sidewall; a light guide plate, which is carried on the backplane and includes a light incidence end section, a light exit surface, and a bottom surface opposite to the light exit surface; a light source, which is mounted on the sidewall and adjacent to the light incidence end section; an intermediate frame, which is set on and covers the light guide plate and the light source; a first retention slot, which is formed in the light incidence end section and has an opening facing the intermediate frame; a second retention slot, which is formed in the light incidence end section and close to the first retention slot and has an opening facing the backplane; a first quantum dot strip, which is received in the first retention slot; and a second quantum dot strip, which is received in the second retention slot. The present invention also discloses a liquid crystal display device. The present invention provides an arrangement including quantum dot strips arranged in the light incidence end section in a top-down staggering manner, where the manner of fixing is simple and light emitting from the light source is prevented from directly entering the light guide plate so as to improve the taste of the color of the backlighting.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of liquid crystal displaying technology, and in particular to a backlight module and a liquid crystal display device.

2. The Related Arts

A conventional liquid crystal display device often uses a white light-emitting diode (LED) as a backlight source, which, when properly arranged in combination with a light guide plate and an optic film, could achieve desired backlighting for liquid crystal. With the increasing demands of people for high color gamut, high color saturation, and energy saving, the solutions that are conventionally adopted to achieve white light source, high color gamut, and high color saturation include: using a violet LED in combination with red, green, and blue phosphors; using a blue LED in combination with red and green phosphors; and using a blue LED together with a green LED and a red LED. All these solutions help increase color gamut, but they are difficult to put into practice and costs are high.

The quantum dot (QD) technique is a technique related to a structure of a semiconductor nanometer material that confines electrons in a predetermined range and is composed of extremely small crystals of chemical compounds having a size ranging 1-100 nm. In the QD technique, crystals of different sizes can be used to control light wavelength in order to achieve precise control of light color. Thus, QD materials are used in backlight modules and a light source of a high frequency spectrum (such as a blue LED) is used to replace the conventionally used white LED light source. Being irradiated by lights of high frequencies, the QDs can be excited to emit lights of different wavelengths. Adjusting the size of the QD material would allow for adjustment of the color of the combined light so as to satisfy the demand for backlighting of high color gamut liquid crystal display modules.

FIG. 1shows a known backlight module that uses a quantum dot phosphor film. Referring toFIG. 1, a blue light-emitting diode (LED)11is arranged at a light incidence side surface of a light guide plate12and a quantum dot phosphor film13is arranged on a light exit surface of the light guide plate12, wherein light emitting from the blue LED11is converted by the light guide plate12into planar light and is projected from the light exit surface of the light guide plate12to pass through the quantum dot phosphor film13, where the blue light is converted into backlighting required for a liquid crystal display device. However, for a large-sized liquid crystal display device, the quantum dot phosphor film13must be formed as a large area and this requires an increased amount of quantum dot material. Further, coating of the quantum dot phosphor layer is subjected to severe requirement for uniformity and this leads to a high cost. Further, in the use of the quantum dot phosphor film13, if the configuration of the optic film or the model number of the optic film is different, the light, which is subjected to improvement made by the optic film, after transmitting through the liquid crystal display panel, shows great variations in respect of color and brightness and thus, during the use of the quantum dot phosphor film13, it is generally not allowed to change the optic film configuration, the optic film supplier, or the optic film model number. This imposes limitations to the flexibility and universality of use of the quantum dot phosphor optic film.

FIG. 2shows another known backlight module that uses a quantum dot phosphor film. Referring toFIG. 2, a blue LED21is arranged at a light incidence side surface of a light guide plate22and a quantum dot phosphor is packaged in a glass tube to form a quantum dot phosphor contained glass tube23, wherein the quantum dot phosphor contained glass tube23is disposed between the blue LED21and the light incidence side surface of the light guide plate12. The blue LED11emits blue light that passes though the quantum dot phosphor contained glass tube23to irradiate the light incidence side surface of the light guide plate12. However, adopting this solution requires a complicated manufacture of the quantum dot phosphor contained glass tube23and the cost is high. Further, the quantum dot phosphor contained glass tube23is susceptible to breaking.

SUMMARY OF THE INVENTION

To overcome the above problems of the prior art techniques, an object of the present invention is to provide a backlight module, which comprises: a backplane, which comprises a sidewall; a light guide plate, which is carried on the backplane and comprises a light incidence end section, a light exit surface, and a bottom surface opposite to the light exit surface; a light source, which is mounted on the sidewall and is adjacent to the light incidence end section; an intermediate frame, which is set on and covers the light guide plate and the light source; a first retention slot, which is formed in the light incidence end section and has an opening facing the intermediate frame; a second retention slot, which is formed in the light incidence end section and close to the first retention slot and has an opening facing the backplane; a first quantum dot strip, which is received in the first retention slot; and a second quantum dot strip, which is received in the second retention slot.

Further, the first retention slot and the second retention slot are arranged to be parallel to each other.

Further, the first retention slot has an end contacting an inner end of a bottom of the first retention slot and the first retention slot has an opposite end that is flush with the light exit surface.

Further, the second retention slot has an end contacting an inner end of a top of the second retention slot and the second retention slot has an opposite end that is flush with the bottom surface.

Further, the backlight module further comprises a first reflection layer, wherein the first reflection film layer is arranged on a side of the intermediate frame that faces the backplane; the first reflection film layer has an end positioned against the sidewall; and the first reflection film layer has an opposite end located between the intermediate frame and the light guide plate.

Further, the backlight module further comprises a second reflection layer, wherein the second reflection film layer is arranged on a side of the backplane that faces the intermediate frame and the second reflection film layer has an end positioned against the sidewall.

Further, the backlight module further comprises a light absorption layer, wherein the light absorption layer is arranged between the intermediate frame and the light guide plate and the light absorption layer has an end positioned against the opposite end of the first reflection film layer.

Further, the backplane comprises a plurality of raised blocks formed on a side thereof that faces the light guide plate, wherein the light guide plate is positioned on the raised blocks.

Further, the backlight module further comprises a reflector plate, wherein the reflector plate is arranged between the light guide and backplane and the reflector has an end positioned against an opposite end of the second reflection film layer.

Another object of the present invention is to provide a liquid crystal display device, which comprises a backlight module and a liquid crystal display panel that are arranged to oppose each other. The backlight module supplies displaying light to the liquid crystal display panel to allow the liquid crystal display panel to display images, wherein the backlight module is the backlight module described above.

The present invention provides that quantum dot strips are arranged in the light incidence end section of the light guide plate in a top-bottom staggering manner, where the manner of fixing is simple and light emitting from the light source is prevented from entering the light guide plate by directly transmitting through the light incidence end section of the light guide plate so as to improve the taste of the color of the backlighting supplied from the backlight module to the liquid crystal display panel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described in detail with reference to the attached drawings. However, various different forms may be adopted to embody the present invention and the interpretation of the present invention should not be limited to the embodiments described herein. On the contrary, these embodiments are provided for the purposes of explaining the principle and practical applications of the present invention in order to allow other technical persons of the art field to realize various embodiments of the present invention, as well as various modifications fit for specific intended uses.

FIG. 3is a schematic view showing a structure of a liquid crystal display device according to an embodiment of the present invention.

Referring toFIG. 3, the liquid crystal display device according to the embodiment of the present invention comprises a liquid crystal display panel200and a backlight module100that is arranged to oppose the liquid crystal display panel200, wherein the backlight module100supplies displaying light to the liquid crystal display panel200to allow the liquid crystal display panel200to display images.

The liquid crystal display panel200commonly comprises a thin-film transistor (TFT) array substrate210, a color filter (CF) substrate220that is opposite to the TFT array substrate210, and a liquid crystal layer230interposed between the TFT array substrate210and the CF substrate220, wherein the liquid crystal layer230comprises multiple liquid crystal molecules. Since a specific structure of the liquid crystal display panel200of the instant embodiment is virtually similar to structures of the conventional liquid crystal display panels, no further details will be given here.

A detailed description of a specific structure of the backlight module100according to an embodiment of the present invention will be given as follows.

FIG. 4is a schematic view showing a structure of a backlight module according to an embodiment of the present invention.

Referring toFIG. 4, the backlight module100according to the embodiment of the present invention comprises: a light guide plate110, a light source120, a quantum dot film strip (which will be briefly referred to as quantum dot strip hereinafter)130, a backplane140, an intermediate frame150, a first retention slot160, and a second retention slot170.

Specifically, the backplane140comprises at least one sidewall141. The light guide plate110is carried on the backplane140and comprises a light incidence end section111, a light exit surface112, and a bottom surface113opposite to the light exit surface112, wherein the light incidence end section111faces the sidewall141of the backplane140.

The light source120may be for example a light bar composed of blue light-emitting diodes (LEDs), which is mounted on the sidewall141of the backplane140and is adjacent to the light incidence end section111of the light guide plate110. The intermediate frame150is set on and covers the light guide plate110and the light source120.

A first retention slot160is formed in the light incidence end section111and has an opening facing the intermediate frame150. A second retention slot170is formed in the light incidence end section111and close to the first retention slot160and has an opening facing the backplane140. In the instant embodiment, preferably, the first retention slot160and the second retention slot170are arranged to be parallel to each other.

The first quantum dot strip131is received in the first retention slot160. In the instant embodiment, preferably, the first quantum dot strip131has an end positioned against an inner wall of a bottom of the first retention slot160and the first quantum dot strip131has an opposite end that is flush with the light exit surface112. The second quantum dot strip132is received in the second retention slot170. In the instant embodiment, preferably, the second quantum dot strip132has an end positioned against an inner wall of a top of the second retention slot170and the second quantum dot strip132has an opposite end that is flush with the bottom surface113.

The first quantum dot strip131and the second quantum dot strip132can be formed of, for example, a quantum dot phosphor layer and a transparent external protection layer that encloses the quantum dot phosphor layer. With the quantum dot phosphor layers of the first quantum dot strip131and the second quantum dot strip132being irradiated by the light source120, the quantum dot phosphor layers are excited to generate different color lights so as to form white backlighting desired for the liquid crystal display panel.

Further, to improve light coupling efficiency, the backlight module100according to the embodiment of the present invention further comprises a first reflection layer181, wherein the first reflection layer181is arranged on the side of the intermediate frame150facing the backplane140. The first reflection layer181has an end positioned against the sidewall141of the backplane140and the first reflection film layer181has an opposite end that is located between the intermediate frame150and the light guide plate110.

In addition, the backlight module100according to the embodiment of the present invention further comprises a second reflection layer182, wherein the second reflection layer182is arranged on the side of the backplane140facing the intermediate frame150and the second reflection layer182has an end positioned against the sidewall141of the backplane.

In the instant embodiment, the first reflection layer181and the second reflection layer182may be made of metallic materials having high reflectance, such as silver; however, the present invention is not limited to this.

Further, to prevent light leakage from occurring between the intermediate frame150and the light guide plate110, in the instant embodiment, the backlight module100according to the embodiment of the present invention further comprises a light absorption layer190, wherein the light absorption layer190is arranged between the intermediate frame150and the light guide plate110and the light absorption layer190has an end that is positioned against said opposite end of the first reflection layer181. The light absorption layer190can be for example a black film, but the present invention is not limited to this.

To improve overall heat dissipation of the backlight module100, the backplane140can be made of a metallic material having excellent heat dissipation property and in the instant embodiment, the backplane140is made of aluminum. To further improve heat dissipation of components, such as the light guide plate110, in the instant embodiment, the backplane140comprises a plurality of raised blocks142formed on a side thereof that faces the light guide plate110. The second reflection layer182is arranged on one of the raised blocks142that is immediately adjacent to the sidewall141of the backplane140. The light guide plate110is positioned on the raised blocks142and the light incidence end section111of the light guide plate110is positioned on the one of the raised blocks142that is immediately adjacent to the sidewall141of the backplane140, so that the light guide plate110and the backplane140form therebetween a gap for further improving heat dissipation efficiency.

Further, the backlight module100according to the embodiment of the present invention further comprises a reflector plate180, wherein the reflector plate180is arranged between the light guide plate110and the raised blocks142of the backplane140and the reflector plate180has an end positioned against an opposite end of the second reflection layer182. The reflector plate180functions to reflect light exiting the bottom surface of the light guide plate110back into the light guide plate110in order to improve light utilization of the light guide plate110.

In summary, according to the embodiments of the present invention, quantum dot strips are arranged in the light incidence end section of the light guide plate in a top-bottom staggering manner, where the manner of fixing is simple and light emitting from the light source is prevented from entering the light guide plate by directly transmitting through the light incidence end section of the light guide plate so as to improve the taste of the color of the backlighting supplied from the backlight module to the liquid crystal display panel.

Although a description of specific embodiment has been given to illustrate the present invention, those having ordinary skills of the art may appreciate that various variations in respect of forms and details can be made without departing the spirit and scope of the present invention that are only limited by the appended claims and the equivalents thereof.