CN100383632C - Display panel and liquid crystal display device - Google Patents

Abstract

The invention provides a display panel, comprising a lower substrate, an upper substrate, a liquid crystal layer between the two substrates and a pair of opposite transparent electrodes arranged on both sides of the liquid crystal layer, the pair of transparent electrodes are respectively located on the upper substrate Between the liquid crystal layer and between the lower substrate and the liquid crystal layer, the surface of the lower substrate close to the liquid crystal layer is divided into two regions, one of which forms a transmissive layer, and the other forms a reflective layer , the penetrating layer and the reflective layer are located between the lower substrate and the transparent electrode close to the lower substrate. The invention also provides a liquid crystal display device, which includes a backlight module and a display panel, and the backlight module is located under the display panel. The display panel includes a lower substrate, an upper substrate, a liquid crystal layer between the two substrates and a pair of opposite transparent electrodes arranged on both sides of the liquid crystal layer, and the pair of transparent electrodes are respectively located between the upper substrate and the liquid crystal layer Between the lower substrate and the liquid crystal layer, the surface of the lower substrate close to the liquid crystal layer is divided into two regions, one of which forms a penetrating layer, and the other forms a reflective layer, and the penetrating layer The reflective layer is located between the lower substrate and the transparent electrode close to the lower substrate. The penetrating layer and the reflective layer of the display panel and the liquid crystal display device of the present invention are located in the same plane, which can reduce space utilization and is easy to carry. At the same time, it has two characteristics of penetrating and reflective. Users can decide whether to use the backlight module according to their own lighting needs, and make full use of the external ambient light to achieve the purpose of saving power.

Description

Display panel and liquid crystal display device

【Technical field】

The invention relates to a thin and portable display panel and a thin and power-saving liquid crystal display device.

【Background technique】

Since portable liquid crystal display products emphasize portability, mobile communication, multi-media functions, power saving, and can be used indoors and outdoors, day and night, the small and medium-sized liquid crystal display technology applied to these products will also match this trend. These applications The requirements for the display panel of the product are not only easy to carry, but also emphasize the characteristics of image quality, thinness, power saving, etc., and it can be used outdoors and indoors, day and night.

According to different light sources used by the liquid crystal display device, it can be divided into a transmissive liquid crystal display device and a reflective liquid crystal display device. The transmissive liquid crystal display device needs to install a backlight on the back of the liquid crystal display panel to realize image display, but the energy consumption of the backlight accounts for about half of the energy consumption of the entire transmissive liquid crystal display device, so the power consumption of the transmissive liquid crystal display device larger. The reflective liquid crystal display device can solve the problem of high energy consumption of the transmissive liquid crystal display device, but it is difficult to realize image display in an environment with weak light. In order to solve the defects existing in the two, the research focus of the industry is concentrated on the transflective liquid crystal display device.

Please refer to FIG. 1 , the prior art transflective liquid crystal display device 1 includes two opposite transparent lower substrates 11 and upper substrates 12 , and a liquid crystal layer 13 sandwiched between the lower substrates 11 and the upper substrates 12 . A transparent common electrode 14 and an alignment film 18 are sequentially disposed on the inner surface of the upper substrate 12 , and an upper retarder 122 and an upper polarizer 121 are sequentially disposed on the outer surface of the upper substrate 12 . A transparent electrode 17 , a passivation layer 16 , a reflective electrode 15 and an alignment film 19 are sequentially disposed on the inner surface of the lower substrate 11 , wherein the passivation layer 16 and the reflective electrode 15 have an opening 151 . A lower retarder 112 and a lower polarizer 111 are sequentially disposed on the outer surface of the lower substrate 11 . The upper retarder 122 and the lower retarder 112 are quarter wave plates (λ/4), the alignment films 18 and 19 are homogeneously aligned, and the polarization directions of the upper polarizer 121 and the lower polarizer 111 are perpendicular to each other. The reflective electrode 15 is metal aluminum (Al) with high reflectivity, and the transparent common electrode 14 and the transparent electrode 17 are transparent conductive materials such as Indium Tin Oxide (ITO) or Indium Zinc Oxide (IZO). The liquid crystal layer 13 has different thicknesses, wherein the thickness of the liquid crystal layer 13 between the transparent common electrode 14 and the reflective electrode 15 is d11, and the thickness of the liquid crystal layer 13 between the transparent common electrode 14 and the transparent electrode 17 is d12, wherein d12 is about twice of d11 . The region where the thickness of the liquid crystal layer is d11 is a reflective region, and the region where the thickness of the liquid crystal layer is d12 is a transmissive region.

The optical retardation of the liquid crystal layer 13 in the reflection area is:

Δn.d11=λ/4

Since d12 is approximately twice as large as d11, the optical retardation of the liquid crystal layer 13 in the penetrating region is:

Δn.d12=λ/2

Where Δn is the birefringence index of the liquid crystal layer 13, and λ is the wavelength of the light.

Since the transflective liquid crystal display device 1 has both a transmissive area and a reflective area in one pixel, the two areas have different heights, which causes the transflective semi-reflective liquid crystal display device 1 to have an impossible The disadvantage to overcome is that the thickness is relatively thick, which cannot meet the requirements of thinness and lightness, and is inconvenient to carry.

In addition, as we all know, liquid crystal display devices are non-self-illuminating display devices, which require an external light source to provide sufficient brightness for the liquid crystal panel. However, for portable liquid crystal display products such as mobile phones, PDAs, and digital cameras, they need to be used outdoors frequently, and their functions More and more, for example, a mobile phone not only includes communication functions, but also may include various functions such as DSC camera, MP3 player, DVD, radio, storage hard disk drive, TV tuning circuit, etc., so the requirement for power saving is also increasing. high.

In view of this, it is necessary to provide a thin, portable display panel and a thin, power-saving liquid crystal display device.

【Content of invention】

The object of the present invention is to provide a thin and portable display panel.

Another object of the present invention is to provide a light and thin liquid crystal display device with low power consumption.

The technical solution adopted by the present invention to solve the technical problem is to provide a display panel, which includes a lower substrate, an upper substrate, a liquid crystal layer between the two substrates, and a pair of opposite transparent electrodes arranged on both sides of the liquid crystal layer , the pair of transparent electrodes are respectively located between the upper substrate and the liquid crystal layer and between the lower substrate and the liquid crystal layer, and the surface of the lower substrate close to the liquid crystal layer is divided into two regions, one of which forms a The penetrating layer and another region form a reflective layer, the penetrating layer and the reflective layer are located between the lower substrate and the transparent electrode close to the lower substrate.

Another technical solution adopted by the present invention to solve the technical problem is to provide a liquid crystal display device, which includes a backlight module and a display panel, and the backlight module is located below the display panel. The display panel includes a lower substrate, an upper substrate, a liquid crystal layer between the two substrates and a pair of opposite transparent electrodes arranged on both sides of the liquid crystal layer, and the pair of transparent electrodes are respectively located between the upper substrate and the liquid crystal layer Between the lower substrate and the liquid crystal layer, the surface of the lower substrate close to the liquid crystal layer is divided into two regions, one of which forms a penetrating layer, and the other forms a reflective layer, and the penetrating layer The reflective layer is located between the lower substrate and the transparent electrode close to the lower substrate.

The material of the penetrating layer is indium tin oxide or silicon dioxide, and the material of the reflective layer is nanoparticles dispersed in an indium tin oxide substrate or nanoparticles dispersed in a silicon dioxide substrate.

The liquid crystal display device also includes a dual optical path control device, which is electrically connected to the backlight module through a photosensitive element, and is used to control whether the backlight module is used or not.

Compared with the prior art, the display panel and the liquid crystal display device of the present invention have the advantages of having both transmissive and reflective properties, and the transmissive layer and the reflective layer of the present invention are located in the same plane, thus reducing space utilization rate, making the product easy to carry.

In addition, for the liquid crystal display device of the present invention, the existence of the dual optical path control device allows users to freely adjust the sensitivity of the light sensing element according to their own brightness requirements, and reduces the energy loss of the battery to the minimum within the user's brightness comfort range. value to achieve the purpose of power saving. When the external ambient light is strong, the backlight is not turned on, and the reflective mode is used to emit light, which is very helpful for power saving; when the external ambient light is weak, the backlight is turned on, and the light from the backlight is used to achieve the purpose of lighting. Avoid poor brightness and contrast. Due to the optical coupling effect and high light utilization rate of the nanoparticle coating contained in the reflective layer, the nanoparticle coating area shows good reflectivity, thus improving the light utilization rate and achieving power saving effects .

【Description of drawings】

FIG. 1 is a schematic structural diagram of a transflective liquid crystal display device in the prior art.

FIG. 2 is a schematic structural diagram of a liquid crystal display device of the present invention.

FIG. 3 is a schematic diagram of the working principle of the backlight module of the liquid crystal display device shown in FIG. 2 .

Fig. 4 is a schematic diagram of a product adopting the structure of the liquid crystal display device of the present invention.

【Detailed ways】

Please refer to FIG. 2 , which is a schematic diagram of the structure of a pixel region of the liquid crystal display device of the present invention. The liquid crystal display device 20 includes a backlight module 21 and a display panel 22 , the backlight module 21 is located below the display panel 22 and provides the backlight required by the display panel 22 . The backlight module 21 includes a light source 214, a light source cover 213 corresponding to the light source 214, a light guide plate 212, a reflector 211, a diffusion plate 215, a Brightness Enhance Film (BEF) 216 and a light concentrator. Film (DualBrightness Enhancement Film, DBEF) 217. The light source 214 can be a cold-cathode fluorescent lamp (CCFL), a light-emitting diode (Light-Emitting Diode, LED) or an LED bundle. The function of the light guide plate 212 is to conduct the light emitted by the light source from the side close to the light source to the side far away from the light source through total reflection, and convert the point light source or line light source into a surface light source with uniform light energy distribution to improve brightness. The reflection plate 211 is located under the light guide plate 212 and its surface is plated with silver or aluminum metal material. The diffusion plate 215 is located above the light guide plate 212 and below the brightness enhancement sheet 216 . There is an air gap as small as possible between the diffuser plate 215 and the light guide plate 212 , for example less than 0.1 mm. The brightness enhancement sheet 216 has a prism microstructure, also known as a prism sheet. The light concentrating sheet 217 is located above the brightness enhancing sheet 216 and has a light concentrating function, and improves the brightness of the liquid crystal panel by improving light utilization efficiency.

The light source 214 is disposed on the edge of the light guide plate 212 and is of side-light type. This design can reduce the weight of liquid crystal display devices such as notebook computers. The light guide plate 212 is wedge-shaped, and the size of the wedge-shaped side near the light source 214 is larger. The wedge-shaped design enables the light energy to be transmitted from the side of the light guide plate 212 close to the light source 214 to the side away from the light source 214 through total reflection.

The display panel 22 includes a transparent lower substrate 221 and an upper substrate 227 oppositely disposed, and a liquid crystal layer 224 is sandwiched between the lower substrate 221 and the upper substrate 227 .

A color filter 226 (Color Filter, CF) is attached to the surface of the upper substrate 227 near the liquid crystal layer 224, and an upper polarizer 228 is attached to the surface of the side away from the liquid crystal layer 224, and the polarizer 228 is attached successively. An anti-glare layer 2291 (anti-glace, AG) and an anti-reflection layer 2292 (anti-reflection, AR), the anti-glare layer 2291 and the anti-reflection layer 2292 are soft designs for visual effects, which can increase the transmittance , Reduce glare.

Two opposite alignment films 2231 , 2232 and two opposite transparent electrodes 2251 , 2252 are sequentially disposed on both sides of the liquid crystal layer 224 . The alignment films 2231, 2232 are homogeneous alignment (Homogeneous Alignment), and its material is polyimide (polyamide, PI), which is a kind of synthetic polyester with high temperature resistance, wear resistance and corrosion resistance, and is mainly used for cladding or coating . The two electrodes are both Indium Tin Oxide (ITO). Transparent Indium Tin Oxide (ITO) not only has high transmittance in the visible light range, but also has high reflectivity in the infrared light range. Optical Selectivity materials that can exhibit different behaviors in different electromagnetic wave frequency ranges. Its light transmittance is 90% to 99% in the visible light range. The ITO film is deposited on the surfaces of the alignment films 2231 and 2232 by means of reactive direct current (DC) sputtering or reactive radio frequency (Radio Frequency, RF) sputtering, through which the working gas argon and the reactive gas oxygen are introduced.

The lower polarizer 2210 is disposed on the surface of the lower substrate 221 away from the liquid crystal layer 224 , and is perpendicular to the polarization direction of the upper polarizer 228 . For each pixel area, the surface of the lower substrate 221 close to the liquid crystal layer 224 is divided into two areas, one of which is a penetrating area, and a penetrating layer 2201 is attached. The material of the penetrating layer 2201 can be Indium tin oxide (ITO) or silicon dioxide (SiO2), the light emitted by the backlight module 21 can pass through this area, and its transmittance is greater than 90%. The other area is the reflective area, and a reflective layer 2202 is attached. The reflective layer 2202 adopts nano-reflective-coating (NRC) technology, and the nanoparticles are dispersed in indium tin oxide ITO or silicon dioxide (SiO2 ) substrate, the nanoparticle can be aluminum (aluminum, Al) or silver (silver, Ag), and its size is between 2nm to 100nm, preferably 5nm to 20nm. The thickness of the transmission layer 2201 and the reflection layer 2202 is between 100 nm and 500 nm. Due to the light coupling effect and high light utilization efficiency of the nanoparticle coating, sunlight or ambient light shows good reflectivity in the nanoparticle coating area.

On the transmissive layer 2201 and the reflective layer 2202 is a thin film transistor 222 (Thin Film Transistor, TFT), which is used to actively control the luminous flux of each pixel, so it is also called "active matrix thin film transistor".

FIG. 3 is a working principle diagram of the backlight module 21 shown in FIG. 2 . The light source emits a light beam that can be regarded as composed of P-polarized light and S-polarized light whose two polarization states are perpendicular to each other. The light beam reaches the lower polarizing plate 2210 after passing through the light guide plate 212, the diffuser plate 215, the brightness enhancement film 216 and the light-condensing film (DBEF) 217 , wherein the polarization state of the P polarized light is perpendicular to the polarization state of the lower polarizer 2210, and the polarization state of the S polarized light is parallel to the polarization state of the lower polarizer 2210, so only the S polarized light can pass through the lower polarizer 2210, P The polarized light is reflected to the backlight module 21 after being polymerized by the light-condensing plate 217, and then recycled, and then converted into relatively weak P-polarized light and S-polarized light, so that all the reflected P-polarized light can be fully utilized through the infinite conversion of the recovery type . When the condenser sheet 217 is not used, only the S polarized light can pass through the polarizing plate, most of the P light is absorbed by the polarizing plate itself and generates heat, and a small part is converted into P polarized light and S polarized light with very weak intensity. Therefore, the use of the condensing sheet 217 greatly improves the light utilization rate.

For the liquid crystal display device 20, the liquid crystal layer 224 is used to adjust the luminous flux. Liquid crystals can change their molecular structure to allow varying amounts of light to pass through them, or to block light entirely. The liquid crystal display device 20 includes two polarizers 2210, 228, a color filter 226, and alignment films 2231, 2232, which can determine the maximum value of light flux and the generation of colors. The liquid crystal layer 224 is located between the upper substrate 227 and the lower substrate 221. When a voltage is applied to the alignment films 2231 and 2232 on both sides of the liquid crystal layer 224, an electric field is generated to make the liquid crystal at the interface of the alignment films 2231 and 2232 face a certain direction. arrangement.

FIG. 4 is a schematic diagram of a product 30 adopting the structure of the liquid crystal display device of the present invention. This product 30 includes various functions such as DSC camera 33, MP3 player 34, DVD 36, radio 35, storage hard disk drive 37, TV tuning circuit 31, still has a pair of optical path control devices (Dual Light Control, DLC) on the surface of this product 30 38. For such a multifunctional liquid crystal display device, power saving is very necessary. The dual optical path control device 38 is connected to a light sensing element (not shown) inside the product 30, the light sensing element is a light emitting diode switch element (light diode switch, LDS), which is electrically connected to the backlight module 21, through Whether the use of the backlight module 21 is controlled is to control the adoption of the reflective mode or the adoption of the transmissive mode. It has adjustable sensitivity, and users can freely adjust the sensitivity of the light sensing element according to their own brightness requirements, so that the energy loss of the battery can be reduced to the minimum value within the visual comfort range.

When the ambient light intensity is sufficient, the external ambient light is directly used as the light source in order to save power. At this time, the light sensing element (not shown in the figure) controls the backlight module 21 to not emit light, and the liquid crystal display device 20 adopts the reflective mode at this time. Due to the optical coupling effect and high light utilization efficiency of the nanoparticle coating contained in the reflective layer 2202, the external ambient light shows good reflectivity in the nanoparticle coating area, and is evenly reflected to the surroundings of the panel to achieve luminescence. The purpose of this method is to effectively improve the problem of high power consumption of the liquid crystal display device and achieve power saving effect.

When the light intensity of the external environment is very weak or when the user is dissatisfied with the light comfort, the dual optical path control device 38 can be activated, and the light sensing element (not shown) connected to it controls the backlight module 21 to emit light, and the liquid crystal display The device 20 is now in pass-through mode. The uniform light beam generated by the backlight module 21 can pass through the penetrating layer 2201 , but cannot pass through the reflective layer 2202 containing nanoparticles. Under the action of the electric field provided by the thin film transistor 222, the luminous fluxes of different pixels are accurately limited, thereby obtaining color patterns.

Compared with the height-controlled semi-transmissive and semi-reflective liquid crystal display devices in the prior art, the transmissive layer 2201 and the reflective layer 2202 of the present invention are located in the same plane, which can reduce space utilization and make the product easy to carry; The existence of the optical path control device 38 enables the user to freely adjust the sensitivity of the light sensing element according to the user's own brightness requirements, so that the energy loss of the battery is reduced to the minimum value within the user's brightness comfort range, and the purpose of power saving is achieved; due to the reflective layer 2202 The optical coupling effect and high light utilization rate of the nano-particle coating contained in the nano-particle coating area show good reflectivity, so the light utilization rate is improved and the power saving effect is achieved.

The liquid crystal display device adopted by the present invention can be used for DSC cameras, MP3 players, DVDs, radios, storage hard drives, video cameras, TV tuning circuits, and can also be used for mobile phones, PDAs, personal multimedia players, notebook computers, and automotive display devices, etc. .

Claims (20)

1. display panel, it comprises a pair of relative transparency electrode that an infrabasal plate, a upper substrate and are positioned at the liquid crystal layer between two substrates and are arranged on these liquid crystal layer both sides, this a pair of transparency electrode lays respectively at and reaches between this infrabasal plate and this liquid crystal layer between this upper substrate and this liquid crystal layer, it is characterized in that: this infrabasal plate is divided into two zones near this liquid crystal layer one side surface, the one zone forms a penetrated bed, another zone forms a reflection horizon, and this penetrated bed and this reflection horizon are at this infrabasal plate and near between the transparency electrode of this infrabasal plate.

2. display panel as claimed in claim 1 is characterized in that: the material of this penetrated bed is indium tin oxide or silicon dioxide.

3. display panel as claimed in claim 1 is characterized in that: the material in this reflection horizon is to contain in the indium tin oxide base material in nano particle or the silicon dioxide base material to contain nano particle.

4. display panel as claimed in claim 3 is characterized in that: this nano particle is silver or aluminium.

5. display panel as claimed in claim 3 is characterized in that: the size of this nano particle arrives 100nm between 2nm.

6. display panel as claimed in claim 5 is characterized in that: the size of this nano particle arrives 20nm between 5nm.

7. display panel as claimed in claim 1 is characterized in that: the thickness in this penetrated bed and this reflection horizon is that 100nm is to 500nm.

8. display panel as claimed in claim 1 is characterized in that: this infrabasal plate outer surface attaches Polarizer.

9. display panel as claimed in claim 1 is characterized in that: these liquid crystal layer both sides are provided with a pair of relative alignment film, and each alignment film is between this liquid crystal layer and corresponding transparency electrode.

10. display panel as claimed in claim 9 is characterized in that: this alignment film is a horizontal direction matching, and its material is a polyimide.

11. display panel as claimed in claim 9 is characterized in that: this transparency electrode is an indium tin oxide.

12. display panel as claimed in claim 11 is characterized in that: this indium tin oxide film is to be deposited on the alignment film surface with reaction equation dc sputtering or reaction equation radio frequency method for sputtering.

13. display panel as claimed in claim 1 is characterized in that: this penetrated bed, reflection horizon and existence one thin film transistor (TFT) between the transparency electrode of this liquid crystal layer downside.

14. display panel as claimed in claim 1 is characterized in that: this upper substrate attaches a colored filter near this liquid crystal layer one side surface, attaches Polarizer on, an anti-glare layer and an anti-reflecting layer successively away from this liquid crystal layer one side surface.

15. liquid crystal indicator, it comprises a module backlight and a display panel, this module backlight is positioned at this display panel below, this display panel comprises an infrabasal plate, one upper substrate and one is positioned at the liquid crystal layer between two substrates and is arranged on a pair of relative transparency electrode of these liquid crystal layer both sides, this a pair of transparency electrode lays respectively at and reaches between this infrabasal plate and this liquid crystal layer between this upper substrate and this liquid crystal layer, it is characterized in that: this infrabasal plate is divided into two zones near this liquid crystal layer one side surface, the one zone forms a penetrated bed, another zone forms a reflection horizon, and this penetrated bed and this reflection horizon are at this infrabasal plate and near between the transparency electrode of this infrabasal plate.

16. liquid crystal indicator as claimed in claim 15 is characterized in that: also comprise a pair of light path control device, this double light path control device electrically connects by a photoinduction element and module backlight, whether uses in order to control module backlight.

17. liquid crystal indicator as claimed in claim 15, it is characterized in that: this module backlight comprise a light source, with the corresponding light source cover of this light source and light guide plate, a reflecting plate, a diffuser plate, a blast sheet and a concentration piece, this reflecting plate, this light guide plate, this diffuser plate, this blast sheet and this concentration piece are cascading below this display panel, wherein, this concentration piece is located immediately at this display panel below.

18. liquid crystal indicator as claimed in claim 17 is characterized in that: this light source is cathode fluorescent tube, light emitting diode and LED bundle.

19. liquid crystal indicator as claimed in claim 17 is characterized in that: between this diffuser plate and this light guide plate clearance is arranged, its thickness is 0.1nm.

20. liquid crystal indicator as claimed in claim 17 is characterized in that: this reflecting plate surface is coated with silver or aluminum metallic material.

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