Liquid crystal display device and OLED backlight module thereof

Abstract

The present disclosure provides a liquid crystal display device and an OLED backlight module thereof. The liquid crystal display device comprises a liquid crystal display panel, an OLED backlight module, and a transparent optical adhesive bonding the liquid crystal display panel and the OLED backlight module. The OLED backlight module comprises a backlight substrate, an anode metal layer, a first hole transport layer, a first organic light emitting layer, a first electron transport layer, a charge generation layer, a second hole transport layer, a second organic light emitting layer, a second electron transport layer, a transparent cathode metal layer, and a thin film encapsulation layer stacked on the backlight substrate in sequence, and the first organic light emitting layer and the second organic light emitting layer are connected in series between the anode metal layer and the transparent cathode metal layer. Thus, the brightness of the backlight can be improved under the same driving current density, the driving current density can be reduced, the service life can be prolonged, and the thickness of the liquid crystal display device can be reduced under the condition of obtaining the same brightness.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a liquid crystal display device and its OLED backlight module. Background Technology

[0002] Liquid crystal displays (LCDs) use a liquid crystal display panel to modulate backlighting to display images. The liquid crystal display panel itself does not emit light; it requires a backlight module to provide a surface light source. In recent years, the requirements for overall thickness in products such as portable displays and automotive displays have been continuously increasing.

[0003] The backlight of existing liquid crystal display (LCD) devices typically consists of an outer metal frame, light-emitting diode (LED) chips, and multiple functional films. Edge-lit backlight modules generally include components such as a light guide plate, reflector, diffuser film, and prism sheet, while direct-lit backlight modules generally include components such as a diffuser plate and prism sheet. Organic light-emitting diode (OLED) devices are characterized by self-illumination and simple structure. Related technologies propose placing an OLED backlight source below the LCD panel to eliminate the need for a light guide plate and optical films. Such a backlight source typically includes a substrate, and sequentially stacked layers on the substrate: an anode, a hole injection layer, a hole transport layer, a white light emitting layer, an electron transport layer, an electron injection layer, a transparent cathode, and a thin-film encapsulation layer.

[0004] However, the aforementioned backlights typically employ a single-layer light-emitting layer, consisting of an organic light-emitting layer between the anode and a transparent cathode that provides white light. The luminous intensity of the organic light-emitting layer is related to the driving current density flowing between the anode and the transparent cathode. To achieve the brightness required for liquid crystal displays, it is often necessary to increase the driving current density. However, the degradation rate of organic light-emitting materials accelerates with increasing driving current density, and the luminous efficiency decreases with increasing usage time, correspondingly shortening the lifespan of the backlight. In other words, when using a single-layer light-emitting layer, it is often difficult to simultaneously achieve both high brightness and long lifespan. Furthermore, when the backlight emits light over a large area, the organic light-emitting material layer often needs to be reliably encapsulated to suppress degradation caused by moisture and oxygen intrusion. Therefore, how to reduce the thickness of the liquid crystal display device while ensuring a long lifespan for the backlight to achieve the required brightness has become a technical problem that needs to be solved. Summary of the Invention

[0005] This disclosure is made in view of the above-mentioned state of the prior art, and its purpose is to provide a liquid crystal display device with OLED backlight, so as to reduce the thickness of the liquid crystal display device while giving the backlight high brightness and long service life.

[0006] Therefore, the first aspect of this disclosure provides an OLED backlight module for a liquid crystal display device. The liquid crystal display device includes a liquid crystal display panel and the OLED backlight module, wherein the OLED backlight module is disposed on the light-incident side of the liquid crystal display panel. The module is characterized by comprising a backlight substrate, an anode metal layer, a first hole transport layer, a first organic light-emitting layer, a first electron transport layer, a charge generation layer, a second hole transport layer, a second organic light-emitting layer, a second electron transport layer, and a transparent cathode metal layer sequentially stacked on the backlight substrate facing the liquid crystal display panel, and a thin film encapsulation layer disposed on the transparent cathode metal layer facing away from the backlight substrate. The first organic light-emitting layer and the second organic light-emitting layer are connected in series between the anode metal layer and the transparent cathode metal layer, and the charge generation layer is located between the first organic light-emitting layer and the second organic light-emitting layer, the charge generation layer being used to provide charge carriers to the first organic light-emitting layer and the second organic light-emitting layer. In this disclosure, the liquid crystal display panel and the OLED backlight module are bonded together using a transparent optical adhesive. A charge generation layer is located between the first and second organic light-emitting layers (OLEDs) and generates electrons and holes under the influence of an applied electric field. Therefore, the first and second OLEDs can emit light in series under the same driving current. Consequently, at the same driving current density, the light emitted by the two OLEDs is superimposed, increasing the backlight brightness. To achieve the same brightness, the driving current density can be reduced, slowing down the degradation rate of the organic light-emitting materials and extending the lifespan of the backlight. Furthermore, a thin-film encapsulation layer is disposed on the side of the transparent cathode metal layer facing away from the backlight substrate, blocking moisture and oxygen, thereby suppressing the degradation of the organic light-emitting material layers and further extending the lifespan. Moreover, the OLED backlight module eliminates the need for a light guide plate, diffusion film, and prism sheet, reducing the thickness of the liquid crystal display device.

[0007] In the OLED backlight module according to the first aspect of this disclosure, optionally, the OLED backlight module further includes a hole injection layer disposed between the anode metal layer and the first hole transport layer. This reduces the energy level barrier between the anode metal layer and the first hole transport layer, thereby reducing the turn-on voltage of the OLED backlight module.

[0008] In the OLED backlight module according to the first aspect of this disclosure, optionally, the OLED backlight module further includes an electron injection layer disposed between the second electron transport layer and the transparent cathode metal layer. This reduces the electron injection barrier between the transparent cathode metal layer and the second electron transport layer, thereby reducing the driving voltage of the OLED backlight module.

[0009] In the OLED backlight module according to the first aspect of this disclosure, optionally, the liquid crystal display device having an OLED backlight further includes a thermally conductive heat dissipation film disposed on the side of the backlight substrate facing away from the anode metal layer. This allows the heat generated by the OLED backlight module to be conducted outwards, thereby suppressing the temperature rise of the OLED backlight module.

[0010] In the OLED backlight module disclosed in the first aspect, optionally, the backlight substrate is an ultra-thin glass substrate or a flexible polyimide substrate, and the thickness of the backlight substrate is no more than 0.3 mm. This reduces the dimension of the OLED backlight module in the thickness direction, thereby enabling the liquid crystal display device to be thinner and lighter.

[0011] In the OLED backlight module disclosed in the first aspect, optionally, the anode metal layer is an opaque metal layer, and the material of the anode metal layer includes any one of silver, molybdenum, aluminum, titanium and copper, or a composite layer formed of any two of silver, molybdenum, aluminum, titanium and copper. This allows the anode metal layer to reflect light incident on the backlight substrate, thereby improving the light extraction efficiency of the backlight.

[0012] In the OLED backlight module disclosed in the first aspect, the transparent cathode metal layer may optionally be made of indium tin oxide or indium zinc oxide. This allows backlight to pass through the transparent cathode metal layer and be emitted into the liquid crystal display panel.

[0013] In the OLED backlight module disclosed in the first aspect, optionally, both the first organic light-emitting layer and the second organic light-emitting layer are white organic light-emitting layers. This enables the OLED backlight module to provide white backlight to the liquid crystal display panel, thereby enabling the liquid crystal display panel to display color images.

[0014] In the OLED backlight module according to the first aspect of this disclosure, optionally, a thin-film encapsulation layer covers the surface of each film layer in the OLED backlight module that is away from the backlight substrate and the edge section of each film layer. This isolates moisture and oxygen, thereby extending the lifespan of the OLED backlight module.

[0015] In the OLED backlight module according to the first aspect of this disclosure, optionally, each film layer located between the anode metal layer and the transparent cathode metal layer constitutes an organic light-emitting material layer, and along a direction perpendicular to the backlight substrate, the orthogonal projection of the thin-film encapsulation layer covers and extends beyond the orthogonal projection of the organic light-emitting material layer. This allows the edge section of the organic light-emitting material layer to be covered by the thin-film encapsulation layer, thereby suppressing the intrusion of moisture and oxygen from the edges into the organic light-emitting material layer.

[0016] In the OLED backlight module according to the first aspect of this disclosure, optionally, the orthographic projection of the organic light-emitting material layer covers the overlapping area formed by the overlapping of the anode metal layer and the transparent cathode metal layer, and the area of ​​the orthographic projection of the organic light-emitting material layer is larger than the area of ​​the overlapping area. Therefore, the anode metal layer and the transparent cathode metal layer can be separated by the organic light-emitting material layer at their edges, thereby suppressing short circuits between the anode metal layer and the transparent cathode metal layer.

[0017] In the OLED backlight module according to the first aspect of this disclosure, optionally, the anode metal layer includes an anode body and an anode terminal connected to the anode body, and the transparent cathode metal layer includes a cathode body and a cathode terminal connected to the cathode body. The anode terminal and the cathode terminal extend beyond the thin-film encapsulation layer and are exposed. Therefore, electrical connection can be provided to the OLED backlight module while maintaining the integrity of the thin-film encapsulation layer, thereby enabling control of the backlight's on / off state and brightness.

[0018] In the OLED backlight module according to the first aspect of this disclosure, optionally, the anode metal layer is an integral electrode layer continuously disposed on one side of the backlight substrate, and the first organic light-emitting layer and the second organic light-emitting layer extend continuously in a plane parallel to the backlight substrate. Thus, the light-emitting area of ​​the OLED backlight module is a continuous area, thereby enabling the provision of a surface light source for the liquid crystal display panel without the need to divide color sub-pixels.

[0019] A second aspect of this disclosure provides a liquid crystal display device, including a liquid crystal display panel, an OLED backlight module as described in the first aspect, and a transparent optical adhesive. The OLED backlight module is disposed on the light-incident side of the liquid crystal display panel, and the transparent optical adhesive is disposed between the liquid crystal display panel and the OLED backlight module. The liquid crystal display panel is bonded to the OLED backlight module through the transparent optical adhesive. In the OLED backlight module disclosed in the second aspect, optionally, the light transmittance of the transparent optical adhesive is greater than or equal to 95%, and the material of the transparent optical adhesive includes acrylic. This reduces light loss between the liquid crystal display panel and the OLED backlight module, and eliminates the need for an air layer between the liquid crystal display panel and the OLED backlight module.

[0020] According to this disclosure, the core technical solution is based on a bonding structure between a liquid crystal display panel and an OLED backlight module, and two organic light-emitting layers connected in series. The liquid crystal display panel and the OLED backlight module are bonded together with a transparent optical adhesive. No light guide plate, diffusion film, or prism sheet is needed between the OLED backlight module and the liquid crystal display panel, reducing the thickness of the liquid crystal display device. Charge carriers are provided to the two organic light-emitting layers through a charge generation layer, enabling the two organic light-emitting layers to emit light in series under the same driving current. This increases the backlight brightness at the same driving current density and reduces the driving current density while achieving the same brightness, slowing down the degradation of the organic light-emitting materials and extending the lifespan of the backlight. The encapsulation relationship between the thin-film encapsulation layer, the organic light-emitting material layer, the anode metal layer, and the transparent cathode metal layer, along with the terminal structure, suppresses moisture and oxygen intrusion and short circuits between the anode metal layer and the transparent cathode metal layer, further extending the lifespan of the OLED backlight module. Attached Figure Description

[0021] Figure 1 This is a schematic diagram showing the cross-sectional structure of a liquid crystal display device with OLED backlight as described in the present disclosure.

[0022] Figure 2 This is a schematic diagram showing the cross-sectional structure of the OLED backlight module involved in the example of this disclosure.

[0023] Figure 3 This is a schematic diagram showing a top view of the OLED backlight module involved in the example of this disclosure.

[0024] Explanation of reference numerals in the attached drawings: 10, Liquid crystal display panel; 20, Transparent optical adhesive; 30, OLED backlight module; 31, Thermally conductive heat dissipation film; 32, Backlight substrate; 33, Anode metal layer; 331, Anode main body; 332, Anode terminal; 34, Hole injection layer; 35, First hole transport layer; 36, First organic light-emitting layer; 37, First electron transport layer; 38, Charge generation layer; 39, Second hole transport layer; 40, Second organic light-emitting layer; 41, Second electron transport layer; 42, Electron injection layer; 43, Transparent cathode metal layer; 431, Cathode main body; 432, Cathode terminal; 44, Thin film encapsulation layer; 45, Organic light-emitting material layer. Detailed Implementation

[0025] The preferred embodiments of this disclosure are described in detail below with reference to the accompanying drawings. The drawings are schematic diagrams, and the thickness and size ratios of the various film layers in the drawings do not represent the proportions of the actual product. In this disclosure, "comprising" means including the listed components without excluding other components, and "disposed of" indicates a positional relationship between two components. "First" and "second" are used to distinguish different components and do not indicate order or importance. In this disclosure, OLED (Organic Light Emitting Diode) refers to a light-emitting diode that uses an organic light-emitting material layer to emit light; LED (Light Emitting Diode) refers to a light-emitting diode that uses a semiconductor material to emit light.

[0026] Figure 1 This is a schematic diagram showing the cross-sectional structure of a liquid crystal display device with OLED backlight as described in the present disclosure.

[0027] like Figure 1 As shown, a liquid crystal display device with OLED backlighting may include a liquid crystal display panel 10, a transparent optical adhesive 20, and an OLED backlight module 30. The OLED backlight module 30 is disposed on the light-incident side of the liquid crystal display panel 10. The light-incident side is the side of the liquid crystal display panel 10 that faces away from the display surface. The transparent optical adhesive 20 is disposed between the liquid crystal display panel 10 and the OLED backlight module 30. The liquid crystal display panel 10 is bonded to the OLED backlight module 30 through the transparent optical adhesive 20.

[0028] In some examples, the liquid crystal display panel 10 can be a twisted nematic liquid crystal display panel, a planar conversion liquid crystal display panel, or a vertical alignment liquid crystal display panel, etc. The liquid crystal display panel 10 itself does not emit light. The liquid crystal display panel 10 displays an image by modulating the light transmission state of each pixel and spatially modulating the backlight from the OLED backlight module 30.

[0029] In some examples, the material of the transparent optical adhesive 20 may include acrylic. In some examples, the light transmittance of the transparent optical adhesive 20 may be greater than or equal to 95%. The light transmittance of the transparent optical adhesive 20 may be 95%, 96%, 97%, 98%, or 99%, etc.

[0030] In some examples, transparent optical adhesive 20 is filled between the liquid crystal display panel 10 and the OLED backlight module 30. No air layer is provided between the liquid crystal display panel 10 and the OLED backlight module 30, and there is no need for light guide plates, diffusion films, or prism sheets for light homogenization. This reduces backlight reflection loss at the interface between the liquid crystal display panel 10 and the OLED backlight module 30, and also reduces the thickness of the liquid crystal display device.

[0031] Figure 2 This is a schematic diagram showing the cross-sectional structure of the OLED backlight module 30 involved in the example of this disclosure. Figure 2 As shown, the OLED backlight module 30 may include a backlight substrate 32, an anode metal layer 33, a first hole transport layer 35, a first organic light-emitting layer 36, a first electron transport layer 37, a charge generation layer 38, a second hole transport layer 39, a second organic light-emitting layer 40, a second electron transport layer 41, a transparent cathode metal layer 43, and a thin-film encapsulation layer 44. The anode metal layer 33, the first hole transport layer 35, the first organic light-emitting layer 36, the first electron transport layer 37, the charge generation layer 38, the second hole transport layer 39, the second organic light-emitting layer 40, the second electron transport layer 41, and the transparent cathode metal layer 43 are sequentially stacked on the side of the backlight substrate 32 facing the liquid crystal display panel 10. The thin-film encapsulation layer 44 is disposed on the side of the transparent cathode metal layer 43 facing away from the backlight substrate 32.

[0032] In some examples, the OLED backlight module 30 may also include a thermally conductive heat dissipation film 31. The thermally conductive heat dissipation film 31 may be disposed on the side of the backlight substrate 32 facing away from the anode metal layer 33. The material of the thermally conductive heat dissipation film 31 may include copper foil. The thermally conductive heat dissipation film 31 can conduct the heat generated by the OLED backlight module 30 during operation to the outside. Therefore, the temperature rise of the OLED backlight module 30 can be suppressed, thereby suppressing the decrease in luminous efficiency as temperature increases.

[0033] In some examples, the backlight substrate 32 can be used to support the aforementioned film layers. The backlight substrate 32 can be an ultra-thin glass substrate or a flexible polyimide substrate. The thickness of the backlight substrate 32 can be no greater than 0.3 mm. The thickness of the backlight substrate 32 can be 0.3 mm, 0.25 mm, 0.2 mm, 0.15 mm, or 0.1 mm, etc. This allows for a reduction in the thickness dimension of the OLED backlight module 30.

[0034] In some examples, the anode metal layer 33 can be an opaque metal layer. The material of the anode metal layer 33 can include any one of silver, molybdenum, aluminum, titanium, and copper, or a composite layer formed from any two of silver, molybdenum, aluminum, titanium, and copper. The anode metal layer 33 can be an integral electrode layer continuously disposed on one side of the backlight substrate 32. The anode metal layer 33 can reflect light incident on the backlight substrate 32. This improves the light extraction efficiency of the backlight.

[0035] In other examples, the OLED backlight module 30 may also include a hole injection layer 34. The hole injection layer 34 may be disposed between the anode metal layer 33 and the first hole transport layer 35. The hole injection layer 34 can reduce the energy level barrier between the anode metal layer 33 and the first hole transport layer 35. The hole injection layer 34 can improve the interfacial contact between the anode metal layer 33 and the first hole transport layer 35. Therefore, the hole injection efficiency can be improved, and the turn-on voltage of the OLED backlight module 30 can be reduced.

[0036] In some examples, the first hole transport layer 35 may be disposed between the hole injection layer 34 and the first organic light-emitting layer 36, or between the anode metal layer 33 and the first organic light-emitting layer 36. The first hole transport layer 35 can transport holes to the first organic light-emitting layer 36. The first hole transport layer 35 can also prevent electrons from moving from the first organic light-emitting layer 36 towards the anode metal layer 33. Therefore, electrons and holes can recombine within the first organic light-emitting layer 36.

[0037] In some examples, the first organic light-emitting layer 36 can be a white organic light-emitting layer. The first organic light-emitting layer 36 can extend continuously in a plane parallel to the backlight substrate 32. The first organic light-emitting layer 36 is capable of emitting white light. The white light emitted by the first organic light-emitting layer 36 can provide backlight for the liquid crystal display panel 10.

[0038] In some examples, a first electron transport layer 37 is disposed between the first organic light-emitting layer 36 and the charge generation layer 38. The first electron transport layer 37 is capable of transporting electrons to the first organic light-emitting layer 36. The first electron transport layer 37 is also capable of preventing holes from moving from the first organic light-emitting layer 36 towards the charge generation layer 38. Thus, electrons and holes can recombine within the first organic light-emitting layer 36.

[0039] In some examples, the charge generation layer 38 can be disposed between the first electron transport layer 37 and the second hole transport layer 39. The charge generation layer 38 can also be located between the first organic light-emitting layer 36 and the second organic light-emitting layer 40. Under the action of an applied electric field, the charge generation layer 38 can generate electrons and holes. The electrons generated by the charge generation layer 38 are supplied to the first organic light-emitting layer 36, and the holes generated by the charge generation layer 38 are supplied to the second organic light-emitting layer 40. That is, the charge generation layer 38 is used to provide charge carriers to the first organic light-emitting layer 36 and the second organic light-emitting layer 40. Thus, the first organic light-emitting layer 36 and the second organic light-emitting layer 40 can emit light in series under the same driving current. At the same driving current density, the white light emitted by the first organic light-emitting layer 36 and the second organic light-emitting layer 40 superimposes, increasing the brightness of the backlight. To achieve the same brightness, the driving current density can be reduced. The degradation rate of organic light-emitting materials accelerates with increasing driving current density; therefore, reducing the driving current density can slow down the degradation of organic light-emitting materials, thereby extending the lifespan of the OLED backlight module 30.

[0040] In some examples, the second hole transport layer 39, the second organic light-emitting layer 40, and the second electron transport layer 41 can be stacked between the charge generation layer 38 and the transparent cathode metal layer 43. The second hole transport layer 39 can be disposed between the charge generation layer 38 and the second organic light-emitting layer 40. The second organic light-emitting layer 40 is a white organic light-emitting layer. The second organic light-emitting layer 40 can extend continuously in a plane parallel to the backlight substrate 32. The second electron transport layer 41 can be disposed between the second organic light-emitting layer 40 and the transparent cathode metal layer 43. The functions of the second hole transport layer 39, the second organic light-emitting layer 40, and the second electron transport layer 41 are the same as those of the first hole transport layer 35, the first organic light-emitting layer 36, and the first electron transport layer 37, respectively.

[0041] In other examples, the OLED backlight module 30 also includes an electron injection layer 42. The electron injection layer 42 may be disposed between the second electron transport layer 41 and the transparent cathode metal layer 43. The electron injection layer 42 can reduce the electron injection barrier between the transparent cathode metal layer 43 and the second electron transport layer 41. This facilitates the injection of electrons from the transparent cathode metal layer 43 into the second electron transport layer 41 and reduces the driving voltage of the OLED backlight module 30.

[0042] In some examples, the transparent cathode metal layer 43 may have light-transmitting properties. The material of the transparent cathode metal layer 43 may include indium tin oxide or indium zinc oxide. The transparent cathode metal layer 43 enables light emitted from the first organic light-emitting layer 36 and the second organic light-emitting layer 40 to be emitted toward the liquid crystal display panel 10.

[0043] In some examples, the thin-film encapsulation layer 44 may be disposed on the side of the transparent cathode metal layer 43 facing away from the backlight substrate 32.

[0044] In some examples, the film layers located between the anode metal layer 33 and the transparent cathode metal layer 43 can constitute an organic light-emitting material layer 45. The thin-film encapsulation layer 44 can cover the surfaces of each film layer in the OLED backlight module 30 that are away from the backlight substrate 32 and the edge sections of each film layer. Thus, the thin-film encapsulation layer 44 can isolate moisture and oxygen, thereby extending the lifespan of the OLED backlight module 30.

[0045] Figure 3 This is a schematic diagram showing a top view of the OLED backlight module 30 as described in this disclosure example.

[0046] like Figure 3 As shown, along a direction perpendicular to the backlight substrate 32, the orthographic projection of the thin-film encapsulation layer 44 covers and extends beyond the orthographic projection of the organic light-emitting material layer 45. The orthographic projection of the thin-film encapsulation layer 44 lies within the orthographic projection of the backlight substrate 32. The orthographic projection of the anode metal layer 33 lies within the orthographic projection of the organic light-emitting material layer 45. The orthographic projection of the organic light-emitting material layer 45 lies within the orthographic projection of the thin-film encapsulation layer 44. Therefore, the edge section of the organic light-emitting material layer 45 can be covered by the thin-film encapsulation layer 44, thereby suppressing the intrusion of moisture and oxygen from the edge into the organic light-emitting material layer 45.

[0047] like Figure 3 As shown, the anode metal layer 33 and the transparent cathode metal layer 43 overlap each other in a direction perpendicular to the backlight substrate 32, forming an overlapping region. The orthographic projection of the organic light-emitting material layer 45 covers this overlapping region. The area of ​​the orthographic projection of the organic light-emitting material layer 45 is larger than the area of ​​the overlapping region. In other words, the organic light-emitting material layer 45 fills the entire overlapping area of ​​the anode metal layer 33 and the transparent cathode metal layer 43, and the area filled by the organic light-emitting material layer 45 extends beyond the overlapping region. Therefore, the anode metal layer 33 and the transparent cathode metal layer 43 can be separated by the organic light-emitting material layer 45 at their edges, thereby suppressing short circuits between the anode metal layer 33 and the transparent cathode metal layer 43.

[0048] like Figure 3As shown, the anode metal layer 33 may include an anode body portion 331 and an anode terminal 332. The anode terminal 332 is connected to the anode body portion 331. The transparent cathode metal layer 43 may include a cathode body portion 431 and a cathode terminal 432. The cathode terminal 432 is connected to the cathode body portion 431. The anode terminal 332 and cathode terminal 432 may extend beyond the thin-film encapsulation layer 44 and be exposed. The anode terminal 332 and cathode terminal 432 can be connected to a drive circuit. Therefore, the on / off state and brightness of the backlight can be controlled while the thin-film encapsulation layer 44 remains intact.

[0049] Since the anode metal layer 33 is a monolithic electrode layer, and the first organic light-emitting layer 36 and the second organic light-emitting layer 40 extend continuously in a plane parallel to the backlight substrate 32, the light-emitting area of ​​the OLED backlight module 30 is a continuous area. In other words, the light-emitting area of ​​the OLED backlight module 30 is equivalent to a single light-emitting area, eliminating the need to divide the OLED backlight module 30 into red, green, and blue sub-pixels. Therefore, the OLED backlight module 30 can provide a surface light source for the liquid crystal display panel 10 without the need for a light guide plate, diffusion film, and prism sheet, thereby reducing the thickness of the liquid crystal display device.

[0050] In some examples, the backlight substrate 32 may be made of other materials; the materials of each film layer in the organic light-emitting material layer 45 may be known organic optoelectronic materials; the material of the transparent optical adhesive 20 may include acrylic optical adhesive or silicone optical adhesive. The examples disclosed herein are not limited thereto.

[0051] The above description is merely an exemplary embodiment of this disclosure. For those skilled in the art, any equivalent substitutions or adjustments made to the materials of each film layer, additional film layers that do not affect the optical path, the thickness of each film layer, and the shape of the wiring terminals without departing from the technical concept of this disclosure should be included within the protection scope of this disclosure.

Claims

1. An OLED backlight module for a liquid crystal display device, the liquid crystal display device comprising a liquid crystal display panel and the OLED backlight module, the OLED backlight module being disposed on the light-incident side of the liquid crystal display panel, characterized in that, The device includes a backlight substrate, an anode metal layer, a first hole transport layer, a first organic light-emitting layer, a first electron transport layer, a charge generation layer, a second hole transport layer, a second organic light-emitting layer, a second electron transport layer, and a transparent cathode metal layer, which are sequentially stacked on the side of the backlight substrate facing the liquid crystal display panel, and a thin film encapsulation layer disposed on the side of the transparent cathode metal layer facing away from the backlight substrate; the first organic light-emitting layer and the second organic light-emitting layer are connected in series between the anode metal layer and the transparent cathode metal layer, and the charge generation layer is located between the first organic light-emitting layer and the second organic light-emitting layer, and the charge generation layer is used to provide charge carriers to the first organic light-emitting layer and the second organic light-emitting layer.

2. The OLED backlight module according to claim 1, characterized in that, The OLED backlight module further includes a hole injection layer, which is disposed between the anode metal layer and the first hole transport layer.

3. The OLED backlight module according to claim 1, characterized in that, The OLED backlight module further includes an electron injection layer, which is disposed between the second electron transport layer and the transparent cathode metal layer.

4. The OLED backlight module according to claim 1, characterized in that, It also includes a thermally conductive heat dissipation film, which is disposed on the side of the backlight substrate away from the anode metal layer.

5. The OLED backlight module according to claim 1, characterized in that, The backlight substrate is an ultra-thin glass substrate or a flexible polyimide substrate, and the thickness of the backlight substrate is no more than 0.3 mm.

6. The OLED backlight module according to claim 1, characterized in that, The anode metal layer is an opaque metal layer, and the material of the anode metal layer includes any one of silver, molybdenum, aluminum, titanium and copper, or a composite layer formed by any two of silver, molybdenum, aluminum, titanium and copper.

7. The OLED backlight module according to claim 1, characterized in that, The transparent cathode metal layer is made of indium tin oxide or indium zinc oxide.

8. The OLED backlight module according to claim 1, characterized in that, Both the first organic light-emitting layer and the second organic light-emitting layer are white light organic light-emitting layers.

9. The OLED backlight module according to claim 1, characterized in that, The thin-film encapsulation layer covers the surface of each film layer in the OLED backlight module that is away from the backlight substrate and the edge section of each film layer.

10. The OLED backlight module according to claim 9, characterized in that, Each film layer located between the anode metal layer and the transparent cathode metal layer constitutes an organic light-emitting material layer. Along a direction perpendicular to the backlight substrate, the orthogonal projection of the thin film encapsulation layer covers and extends beyond the orthogonal projection of the organic light-emitting material layer.

11. The OLED backlight module according to claim 10, characterized in that, The orthographic projection of the organic light-emitting material layer covers the overlapping area formed by the overlap of the anode metal layer and the transparent cathode metal layer, and the area of ​​the orthographic projection of the organic light-emitting material layer is larger than the area of ​​the overlapping area.

12. The OLED backlight module according to claim 9, characterized in that, The anode metal layer includes an anode body and an anode terminal connected to the anode body, and the transparent cathode metal layer includes a cathode body and a cathode terminal connected to the cathode body. The anode terminal and the cathode terminal extend beyond the thin film encapsulation layer and are exposed.

13. The OLED backlight module according to claim 1, characterized in that, The anode metal layer is an integral electrode layer continuously disposed on one side of the backlight substrate, and the first organic light-emitting layer and the second organic light-emitting layer extend continuously in a plane parallel to the backlight substrate.

14. A liquid crystal display device, characterized in that, The invention includes a liquid crystal display panel, an OLED backlight module as described in any one of claims 1-13, and a transparent optical adhesive. The OLED backlight module is disposed on the light-incident side of the liquid crystal display panel, and the transparent optical adhesive is disposed between the liquid crystal display panel and the OLED backlight module. The liquid crystal display panel is bonded to the OLED backlight module through the transparent optical adhesive.

15. The liquid crystal display device according to claim 14, characterized in that, The transparent optical adhesive has a light transmittance of 95% or higher, and the material of the transparent optical adhesive includes acrylic acid.

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