Background
With the development of display technology, liquid crystal displays have become the most developed display device among many flat panel display devices, and the liquid crystal displays have the widest application range and are still rapidly developed. The LCD has the advantages of light weight, low energy consumption, soft picture, good heat dissipation, etc., and is widely applied to display products such as mobile phones, flat panels, televisions, etc. with the continuous reduction of the manufacturing cost of the LCD. At present, most LCD color gamut is about 78% NTSC color gamut, and compared with wide color gamut, the display effect is poorer, and especially, a red area is often distorted when displayed. Recently, due to the narrow emission spectrum of quantum dots, the emission spectrum is easy to control, the quantum yield is high, the absorption spectrum is wide and a wide color gamut (up to more than 120% NTSCS color gamut) is provided, so that the quantum dots become mainstream materials of next generation liquid crystal backlights.
For a traditional lateral-entering quantum dot backlight module, an LED light source is positioned on the side edge of a light guide plate, light emitted by the light source uniformly emits light after color conversion of a quantum dot layer and modulation of microstructures, wherein the quantum dot layer can be arranged at the incident position of a backlight LED in an 'on-edge' mode, and can also be arranged on the light incident side in the light guide plate through an integrated forming process of the light guide plate. However, for such a conventional lateral-type quantum dot backlight module, the distance between the light source and the quantum dot layer is short, and the radiation of the light source and the generated heat may reduce the stability of the quantum dots in the quantum dot layer, thereby affecting the service life of the backlight module.
Disclosure of Invention
The invention aims to provide a lateral-entering type quantum dot backlight module structure which is beneficial to prolonging the service life of the backlight module and reducing the production line cost.
In order to achieve the purpose, the invention adopts the technical scheme that: a side-in quantum dot backlight module structure comprises two excitation light sources provided with reflectors, a light path conversion device and a quantum dot light guide plate, wherein the excitation light sources are respectively positioned at the left side and the right side of the light path conversion device; and one part of light emitted by the excitation light source is reflected by the light path conversion device and then enters the quantum dot light guide plate, the light is emitted after the color conversion of the quantum dot layer and the modulation of the quantum dot light guide plate, and the other part of light emitted to the reflecting cover after passing through the light path conversion device is reflected by the reflecting cover and the action of the light path conversion device and then enters the quantum dot light guide plate again for recycling.
Furthermore, the light path conversion device comprises a light transmission medium layer embedded with a plurality of reflection structures, the size of the light transmission medium layer is matched with that of the quantum dot light guide plate, each excitation light source is provided with at least one reflection structure corresponding to the excitation light source, and the reflection structures are symmetrical about the central axis positions of the two excitation light sources so as to respectively reflect the light emitted by the excitation light sources and emit the light to the quantum dot light guide plate.
Furthermore, the reflecting structure is a reflecting sheet with high reflection or semi-transmission and semi-reflection optical properties, the reflecting surface of the reflecting sheet is high reflection or semi-transmission and semi-reflection properties, and the corresponding surface of the reflecting surface is transmission properties; when the size of the light transmission medium layer is not larger than a set value, only two reflecting sheets respectively corresponding to the excitation light sources are arranged in the light transmission medium layer, and the reflecting sheets with high reflection property are adopted; when the size of the light transmission medium layer is larger than a set value, two reflector plate combined structures respectively corresponding to the excitation light sources are arranged in the light transmission medium layer, each reflector plate combined structure is composed of reflector plates with high reflection and semi-transmission and semi-reflection optical properties, the reflector plate closest to the central axis positions of the two excitation light sources adopts a reflector plate with high reflection property, and the rest of the reflector plates adopt reflector plates with semi-transmission and semi-reflection properties.
Furthermore, the angle and the orientation of the totally-reflecting or semi-transmitting and semi-reflecting reflector plate are arranged according to the positions of the excitation light source and the reflector thereof, the reflector plate is obliquely arranged, and the reflecting surface faces the emergent surface of the light transmission medium layer; the included angle range of the reflecting surface and the excitation light source is 45 degrees +/-30 degrees, and the included angles of the reflecting sheets corresponding to the same excitation light source and the excitation light source are gradually changed, so that Lambert divergent light of the excitation light source is uniformly emitted into the quantum dot light guide plate after being acted by the reflecting sheets; and a reflective coating is arranged on the corresponding surface of the emergent surface of the light transmission medium layer so as to reflect and reuse part of side leakage light.
Furthermore, a device for converting light rays into parallel light rays is arranged between the excitation light source and the light transmission medium layer, so that the light rays entering the light transmission medium layer are easier to control and emit; the light transmission medium has a light diffusion device on its emergent surface to make the converted light uniformly incident into the quantum dot light guide plate.
Further, the quantum dot light guide plate is made of one or more of Polyethylene (PE), polypropylene (PP), polyethylene naphthalate (PEN), Polycarbonate (PC), polymethyl acrylate (PMA) and polymethyl methacrylate (PMMA).
Further, the distance between the excitation light source and the end face of the light path conversion device is 0.1 mm-1 mm; the excitation light source adopts an ultraviolet light source with the wavelength range of 280nm to 400nm, or adopts a blue light source with the central wavelength of 430nm to 480nm and the half-peak width of 15nm to 55 nm; the opening of the reflecting cover is at least larger than the light emitting area of the excitation light source; the thickness of the excitation light source is smaller than or equal to that of the light path conversion device, and the thickness of the light path conversion device is adaptive to that of the quantum dot light guide plate.
Furthermore, the quantum dot layer is arranged on the light incident side in the quantum dot light guide plate through an integrated molding process, or the quantum dot layer is arranged on the surface of the light incident side of the quantum dot light guide plate or between the light path conversion device and the quantum dot light guide plate, or the quantum dot layer is coated or formed on the light emergent surface of the quantum dot light guide plate; and a light scattering structure is arranged at the bottom of the quantum dot light guide plate.
Compared with the prior art, the invention has the following beneficial effects: the utility model provides a novel side income formula quantum dot backlight unit structure, this structural design light path conversion equipment, the light that the light source sent is through the light path conversion after the reentrant quantum dot layer to can effectively reduce the direct radiation and the heat conduction of light source and to the produced influence of quantum dot, improve backlight unit's life, the light source quantity of being applied to in backlight unit that has significantly reduced moreover has reduced and has produced the line cost. Therefore, the invention has strong practicability and wide application prospect.
Detailed Description
The invention is described in further detail below with reference to the figures and the embodiments.
As shown in fig. 1, the present invention provides a side-in quantum dot backlight module structure, which includes two excitation light sources with reflectors, a light path conversion device and a quantum dot light guide plate, wherein the excitation light sources are respectively located at the left and right sides of the light path conversion device, the light path conversion device is located at the side of the quantum dot light guide plate, and the light-in side of the quantum dot light guide plate has a quantum dot layer; and one part of light emitted by the excitation light source is reflected by the light path conversion device and then enters the quantum dot light guide plate, the light is emitted after the color conversion of the quantum dot layer and the modulation of the quantum dot light guide plate, and the other part of light emitted to the reflecting cover after passing through the light path conversion device is reflected by the reflecting cover and the action of the light path conversion device and then enters the quantum dot light guide plate again for recycling.
The light path conversion device comprises a light transmission medium layer embedded with a plurality of reflection structures, the size of the light transmission medium layer is matched with that of the quantum dot light guide plate, each excitation light source is provided with at least one reflection structure corresponding to the excitation light source, and the reflection structures are symmetrical about the central axis positions of the two excitation light sources so as to respectively reflect light emitted by the excitation light sources to the quantum dot light guide plate.
The reflecting structure is a reflecting sheet with high reflection or semi-transmission and semi-reflection optical properties, the reflecting surface of the reflecting sheet is high reflection or semi-transmission and semi-reflection optical properties, and the corresponding surface of the reflecting surface is transmission optical properties; when the size of the light transmission medium layer is not larger than a set value, only two reflecting sheets respectively corresponding to the excitation light sources are arranged in the light transmission medium layer, and the reflecting sheets with high reflection property are adopted; when the size of the light transmission medium layer is larger than a set value, two reflector plate combined structures respectively corresponding to the excitation light sources are arranged in the light transmission medium layer, each reflector plate combined structure is composed of reflector plates with high reflection and semi-transmission and semi-reflection optical properties, the reflector plate closest to the central axis positions of the two excitation light sources adopts a reflector plate with high reflection property, and the rest of the reflector plates adopt reflector plates with semi-transmission and semi-reflection properties. The angle and the direction of the totally-reflecting or semi-transmitting and semi-reflecting reflector plate are arranged according to the positions of the excitation light source and the reflector thereof, the reflector plate is obliquely arranged, and the reflecting surface faces to the emergent surface of the light transmission medium layer; the included angle range of the reflecting surface and the excitation light source is 45 degrees +/-30 degrees, and the included angles of the reflecting sheets corresponding to the same excitation light source and the excitation light source are gradually changed, so that Lambert divergent light of the excitation light source is uniformly emitted into the quantum dot light guide plate after being acted by the reflecting sheets; and a reflective coating is arranged on the corresponding surface of the emergent surface of the light transmission medium layer so as to reflect and reuse part of side leakage light.
A device for converting light rays into parallel light rays is arranged at a certain position between the excitation light source and the light transmission medium layer, so that the light rays entering the light transmission medium layer are easier to control and emit. The device includes but is not limited to convex lens or convex lens combination, etc., and the setting position is adjusted according to the position of the excitation light source and the reflecting cover thereof. The light transmission medium has a light diffusion device on its emergent surface to make the converted light uniformly incident into the quantum dot light guide plate. Such means include, but are not limited to, a scattering particle layer, a concave lens, etc.
The quantum dot light guide plate is made of one or more of Polyethylene (PE), polypropylene (PP), polyethylene naphthalate (PEN), Polycarbonate (PC), polymethyl acrylate (PMA) and polymethyl methacrylate (PMMA).
The distance between the excitation light source and the end face of the light path conversion device is 0.1 mm-1 mm; the excitation light source adopts an ultraviolet light source with the wavelength range of 280nm to 400nm, or adopts a blue light source with the central wavelength of 430nm to 480nm and the half-peak width of 15nm to 55 nm; including but not limited to mercury lamps, LEDs, laser diodes, OLEDs, etc. The opening of the reflecting cover is at least larger than the light emitting area of the excitation light source; the thickness of the excitation light source is smaller than or equal to that of the light path conversion device, and the thickness of the light path conversion device is adaptive to that of the quantum dot light guide plate. The brightness of the backlight module can be improved by increasing the number of the excitation light sources, and the positions of the excitation light sources can be not limited to the two ends of the light path conversion device, and also can be in the light path conversion device.
The quantum dot layer is arranged on the light incident side in the quantum dot light guide plate through an integrated forming process, or the quantum dot layer is arranged on the surface of the light incident side of the quantum dot light guide plate or between the light path conversion device and the quantum dot light guide plate, or the quantum dot layer is coated or formed on the light emergent surface of the quantum dot light guide plate; the quantum dot light guide plate is a general term for light guide plates containing quantum dot color conversion layers at the light incident side or near the light incident side or at the light emergent side, and light scattering structures in the forms of light scattering microstructures or microgrooves and the like are arranged at the bottom of the quantum dot light guide plate. The quantum dot layer can be provided with a water-proof oxygen-isolating layer and a heat dissipation layer, so that the influence of the external environment on the quantum dots is further reduced, and the service life of the backlight module is prolonged.
The first embodiment is as follows:
as shown in fig. 2, the present embodiment provides a novel lateral-entry type quantum dot backlight module structure, which includes two excitation light sources and reflectors thereof, a light path conversion device, and a quantum dot light guide plate. The light path conversion device comprises a light transmission medium layer embedded with a reflector plate, and a light diffusion device is arranged on a light emergent surface of the light transmission medium layer.
The excitation light source is a blue light source, the central wavelength of the blue light source is 450nm, and the half-peak width of the blue light source is 20 nm. The distance between the light source and the end face of the light path conversion device is 0.1mm, a reflecting cover is arranged outside the light source, and the opening of the reflecting cover is larger than the light emitting area of the light source. The thickness of the light source light-emitting unit is slightly smaller than that of the light path conversion device. The excitation light sources are positioned on two end faces of the light path conversion device, and the light emitting areas of the light sources are matched with the areas of the two end faces in the light conversion device.
In the optical path switching device, the light transmission medium carrier is a light guide plate made of PMMA, and as described above, the light emitting area of the excitation light source should be matched with the area of the end face of the light guide plate. Two reflecting sheets with total reflection optical properties are embedded in the light guide plate, the reflecting sheets are obliquely arranged, the reflecting surfaces face the light emergent surface of the light transmission medium layer, the two reflecting sheets are symmetrical about the central axis of the excitation light source, and the included angles between the two reflecting surfaces and parallel light in the excitation light source are 135 degrees respectively. A light diffusion layer is arranged on the light emergent surface of the light guide plate, and SiO is embedded in the light diffusion layer2And the scattering particles enable the converted light to be more uniformly emitted into the quantum dot light guide plate.
The width and the thickness of the quantum dot light guide plate are matched with those of the light transmission light guide plate. The quantum dot layer in the quantum dot light guide plate is arranged on the light incident side in the light guide plate through an integrated forming process.
Example two:
as shown in fig. 3, two convex lenses are introduced into the above structure, the convex lenses are disposed on the end surface of the light transmission medium layer, and the excitation light source is disposed at the focal point of the convex lenses, so that the scattered light emitted from the light source passes through the convex lenses and then becomes parallel light, and the parallel light can be more easily controlled and emitted into the light guide plate.
Example three:
as shown in fig. 4, the present embodiment provides a novel lateral-entry type quantum dot backlight module structure, which includes two excitation light sources and reflectors thereof, a light path conversion device, and a quantum dot light guide plate. The light path conversion device comprises a light transmission medium layer embedded with a reflector plate, a light diffusion device is arranged on a light emergent surface of the light transmission medium layer, and a reflection coating is arranged on a corresponding surface of the light emergent surface of the light transmission medium layer.
The excitation light source is a blue light source, the central wavelength of the blue light source is 450nm, and the half-peak width of the blue light source is 20 nm. The distance between the light source and the end face of the light path conversion device is 0.1mm, a reflecting cover is arranged outside the light source, and the opening of the reflecting cover is larger than the light emitting area of the light source. The thickness of the light source light-emitting unit is slightly smaller than that of the light path conversion device. The excitation light sources are positioned on two end faces of the light path conversion device, and the light emitting areas of the light sources are matched with the areas of the two end faces in the light conversion device.
In the optical path switching device, the light transmission medium carrier is a light guide plate made of PMMA, and as described above, the light emitting area of the excitation light source should be matched with the area of the end face of the light guide plate. In the light guide plate, each excitation light source is provided with two reflection sheets with semi-transparent and semi-reflective optical properties and one reflection sheet with total reflection optical properties, the reflection sheets are obliquely arranged, the reflection surfaces face the light emergent surface of the light transmission medium layer, the angles of the reflection surfaces and the excitation light sources are gradually changed to 45 degrees, 35 degrees and 25 degrees, the reflection sheets are symmetrical about the central axes of the excitation light sources, the reflection sheets close to the central axes of the two excitation light sources are reflection sheets with high reflection properties, and the angle of the reflection sheet corresponding to the other excitation light source corresponds to the angle of the reflection sheet. A light diffusion layer is arranged on the light emergent surface of the light guide plate, and SiO is embedded in the light diffusion layer2ScatteringThe particles enable the converted light to be more uniformly emitted into the quantum dot light guide plate. A layer of reflective coating is spin-coated on the corresponding surface of the light-emitting surface of the light guide plate, and the reflective coating can be made of silver or silver alloy, so that part of side leakage light can be reflected and utilized again.
The width and the thickness of the quantum dot light guide plate are matched with those of the light transmission light guide plate. The quantum dot layer in the quantum dot light guide plate is arranged on the light incident side in the light guide plate through an integrated forming process.
Example four:
as shown in fig. 5, two convex lenses are introduced into the above structure, the convex lenses are disposed on the end surface of the light transmission medium layer, and the excitation light source is disposed at the focal point of the convex lenses, so that the scattered light emitted from the light source passes through the convex lenses and then becomes parallel light, and the parallel light can be more easily controlled and emitted into the light guide plate.
The above are preferred embodiments of the present invention, and all changes made according to the technical scheme of the present invention that produce functional effects do not exceed the scope of the technical scheme of the present invention belong to the protection scope of the present invention.