CN101256302A - Semi-transparent liquid crystal display panel and liquid crystal display device using same - Google Patents

Abstract

The semi-transparent liquid crystal display panel comprises a first substrate and a second substrate, and a liquid crystal layer is sandwiched between the two substrates. The second substrate includes a filter structure, and the filter structure includes a plurality of optical filter elements, which can make at least three colors of light in the light source penetrate the filter structure. Each optical filter element comprises at least two reflective layers and an interstitial layer, the interstitial layer being located between the two reflective layers. When the light source is incident from the first substrate side or the second substrate side, the color lights of the three colors in the light source respectively pass through the corresponding optical filter elements. The light source is, for example, a backlight of a liquid crystal display device or a light source of an external environment.

Description

Semi-transparent liquid crystal display panel and liquid crystal display device using same

technical field

The invention relates to a transflective liquid crystal display panel and a liquid crystal display device using the same, in particular to a transflective liquid crystal display panel with high penetration and good backlight utilization rate and a liquid crystal display device using the same.

Background technique

Generally, transflective liquid crystal displays can use two technologies to achieve semi-transmissive and semi-reflective purposes. The first is to use a semi-transparent and semi-reflective plate, and the second is to divide the pixel into a transmissive area and a reflective area. .

Please refer to FIG. 1 , which illustrates a cross-sectional view of a conventional transflective display panel with a transflective half-reflector. As shown in FIG. 1 , a color filter 12 is arranged on a first substrate 11 of a traditional transflective liquid crystal display panel 1 , a transflective half-reflector 14 is arranged on a second substrate 13 , and a backlight (not shown) (shown) are often arranged on the side of the second substrate 13. The color filter 12 includes, for example, a red filter layer 121 , a green filter layer 122 and a blue filter layer 123 . In normal mode when the backlight is turned on, light from the backlight L passes through the transflector 14 on the second substrate 13 and the color filter 12 on the first substrate 11 to display colors. In order to achieve the effect of semi-transmission and semi-reflection, generally the penetration rate of the semi-transmission and semi-reflection plate 14 is not high, so that the utilization rate of the backlight L is not good. Of course, in the reflective mode when the backlight L is turned off, the efficiency of utilizing the ambient light source L' is not high.

Please also refer to FIG. 2 , which shows a cross-sectional view of a conventional transflective display panel having a transmissive area and a reflective area. As shown in FIG. 2 , a color filter 22 is also arranged on the first substrate 21 of another traditional transflective liquid crystal display panel 2, and the color filter 12 includes, for example, a red filter layer 221, a green filter layer layer 222 and blue filter layer 223 . A plurality of reflective plates 24 are disposed on the second substrate 23 to display corresponding to each pixel structure. These reflectors 24 will occupy part of the area of each pixel structure. In the general penetration mode, the backlight L will penetrate some pixel structures without reflectors to display images. As for the reflective mode, the light source L' of the external environment penetrates the first substrate 21 and is reflected by the reflective plate 24 on the second substrate 23 to display images. However, since the reflection plate 24 will affect the aperture ratio of each pixel structure, this design will also cause the problem of poor display effect.

In addition, the color filters 12 and 22 shown in FIGS. 1 to 2 are mostly manufactured by coating with pigments, which have the property of absorbing light, which will affect the light utilization rate, so that the transflective liquid crystal display panel 1 Or 2, the color performance of the liquid crystal display device is poor. In order to achieve the luminance and display characteristics required by customers, the backlight module must require more driving power, which makes the entire liquid crystal display device consume more power.

Contents of the invention

The invention relates to a transflective liquid crystal display panel and a liquid crystal display device using the same. By setting a filter structure on the substrate of the transflective liquid crystal display panel, the filter structure has a plurality of optical filter elements for selective use. Visible light penetration in a specific bandwidth range. The optical filter element is composed of two reflective layers and a gap layer. The adjustment of its material and thickness can control the transmission spectrum of visible light, so it has the effect of displaying individual colors. Due to the high light utilization of the optical filter element, the penetration is good. In addition, since the backlight module of the liquid crystal display device reflects and utilizes the backlight reflected by the display panel again, the utilization rate of the backlight is increased.

The present invention provides a transflective liquid crystal display panel, which includes a first substrate and a second substrate, and a liquid crystal layer is located between the first substrate and the second substrate. The second substrate includes a filter structure, and the filter structure includes a plurality of optical filter elements, and these optical filter elements allow at least three colors of light in the light source to pass through the filter structure. Each of these optical filter elements includes at least two reflective layers and a gap layer, and the gap layer is located between the two reflective layers.

The present invention further provides a liquid crystal display device, which includes a transflective liquid crystal display panel and a backlight module, and the backlight module is arranged on one side of the transflective liquid crystal display panel. The transflective liquid crystal display panel includes a first substrate and a second substrate with a liquid crystal layer between the first substrate and the second substrate. The second substrate includes a filter structure, and the filter structure includes a plurality of optical filter elements, and these optical filter elements allow at least three colors of light in the light source to pass through the filter structure. Each optical filter element includes at least two reflective layers and a gap layer, and the gap layer is located between the two reflective layers.

In order to make the above content of the present invention more obvious and understandable, the preferred embodiments are specifically cited below, together with the accompanying drawings, and are described in detail as follows:

Description of drawings

FIG. 1 illustrates a cross-sectional view of a conventional transflective display panel with a transflective half-reflector.

FIG. 2 is a cross-sectional view of a traditional transflective display panel with a transmissive area and a reflective area.

FIG. 3 is a cross-sectional view of a transflective liquid crystal display panel according to a preferred embodiment of the present invention.

FIG. 4 is a cross-sectional view of the filter structure in FIG. 3 .

FIGS. 5A-5C illustrate the spectrum diagrams of individual transmitted light of the optical filter element of FIG. 4 .

6A-6C illustrate the spectrum diagrams of individual reflected light of the optical filter element of FIG. 4 .

FIG. 7A shows a cross-sectional view of a liquid crystal display device in reflective mode according to the present invention.

FIG. 7B is a cross-sectional view of the liquid crystal display device in FIG. 7A in a transmissive mode.

FIG. 8 is a cross-sectional view showing an increased distance between the display panel and the backlight module in FIG. 7B .

Explanation of reference signs

1, 2, 3: transflective liquid crystal display panel 11, 21, 31: first substrate

12, 22: Color filter 13, 23, 33: Second substrate

14: Semi-penetrating and semi-reflecting plate 24: Reflecting plate

35: Filter structure 121, 221: Red filter layer

122, 222: Green filter layer 123, 223: Blue filter layer

350: black matrix 351～353: optical filter element

351A, 351B, 352A, 352B, 353A, 353B: reflective layer

351C～353C: Gap layer 400: Liquid crystal display device

410: Backlight module P: Pixel unit

Detailed ways

Please refer to FIG. 3 , which shows a cross-sectional view of a transflective liquid crystal display panel according to a preferred embodiment of the present invention. As shown in FIG. 3 , the transflective liquid crystal display panel 3 includes a first substrate 31 and a second substrate 33 arranged in parallel, and a liquid crystal layer (not shown) is sandwiched between the first substrate 31 and the second substrate 33 . The second substrate 33 includes a filter structure 35, and the filter structure 35 includes a plurality of optical filter elements 351-353 (see FIG. 4). Each of the optical filter elements 351 - 353 includes at least two reflective layers and a gap layer, and the gap layer is located between the two reflective layers.

With proper design, when the light source passes through individual optical filter elements 351-353, different colors will be displayed. As shown in FIG. 3, the aforementioned filter structure 35 includes, for example, a black matrix 350, an optical filter element 351 capable of displaying red, an optical filter element 352 capable of displaying green, and an optical filter element 353 capable of displaying blue. The optical filter elements 351 - 353 are disposed in the black matrix 350 to be separated from each other. Each of the optical filter elements 351 - 353 is configured corresponding to a pixel structure in the display panel 1 . Please also refer to FIG. 4 , which shows a cross-sectional view of the filter structure in FIG. 3 . As shown in Figure 4, each optical filter element 351-353 includes two reflective layers and a gap layer. Under the design of the structure, material and thickness of the optical filter elements 351-353, the light source passes through these optical filters. The optical elements 351-353 all have different transmission spectra. Of course, in practical application, each optical filter element 351-353 can have two reflective layers 351A, 351B, 352A, 352B, 353A, 353B of the same material and thickness, and only the gap layers 351C, 352C, 353C The thickness design is different to achieve the effect of displaying different colors. Preferably, the reflective layers are each about 5 nanometers to 60 nanometers (nm) thick, and the interstitial layers are about 10 nm to 900 nm thick. The reflective layer is made of, for example, silver (Ag) or silver alloy, and the gap layer is, for example, a dielectric layer or a metal conductive oxide. The material of the aforementioned dielectric layer includes, for example, magnesium fluoride (MgF ₂ ), silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), titanium dioxide (TiO ₂ ), zirconium dioxide (ZrO ₂ ) or Materials such as niobium (Nb ₂ O ₅ ). The material of the metal conductive oxide includes indium tin oxide (ITO), indium zinc oxide (IZO) or aluminum zinc oxide (AZO).

Table 1

  Film Structure Material   Thickness range (nm) All reflective layers silver 5～60   Gap layer 351C Silica 150-200   Gap layer 352C Silica 110-160   Gap layer 353C Silica 70-110

The light transmission and reflection characteristics of the optical filter elements 351 - 353 are described with examples below. Please refer to Table 1 and FIGS. 5A to 5C. FIGS. 5A to 5C show the spectrum diagrams of the individual transmitted light of the optical filter elements in FIG. Thick design. In general visible light, the wavelength of red light is about 650 nanometers, the wavelength of green light is about 546.1 nanometers, and the wavelength of blue light is about 450 nanometers. Here, the filter structure 13 is irradiated with a white light source, and the transmittance of light of various wavelengths after the light source passes through each optical filter element 351 - 353 is measured. As shown in FIG. 5A , when the thickness of the gap layer 351C is between 150-200 nm, the transmittance of visible light with a wavelength between about 650 nm and 670 nm is the highest. At this time, visible light similar to red light is displayed, and the optical filter element 351 thus has the effect of appearing red. As shown in FIG. 5B , when the thickness of the gap layer 352C is between 110-160 nm, the transmittance of visible light with a wavelength around 550 nm is the highest, and at this time, visible light similar to green light is displayed, and the optical filter element 352 thus has a display Green effect. As shown in FIG. 5C , when the thickness of the gap layer 353C is between 70-110 nm, the transmittance of visible light with a wavelength between about 420 nm and 440 nm is the highest. At this time, visible light similar to blue light is displayed, and the optical filter element 353 Has the effect of showing blue. Since the light transmission spectra of the optical filter elements 351 - 353 have a narrower bandwidth, the color purity is higher and the display effect is better.

Please refer to FIGS. 6A-6C again, which illustrate the spectrum diagrams of individual reflected light of the optical filter element in FIG. 4 . As shown in FIG. 6A , the optical filter element 351 allows visible light (approximately red light) with a wavelength between 650nm and 670nm to pass through, so that the light source will display mixed-color light of green light and blue light after being reflected by the optical filter element 351 (e.g. cyan light). Similarly, as shown in FIGS. 6B-6C , the optical filter element 352 can transmit visible light (similar to green light) with a wavelength near 550nm, so that the light source will display red light and blue light after being reflected by the optical filter element 352. Mixed color light (such as purple light). The optical filter element 353 will allow visible light (approximately blue light) with a wavelength in the range of 420nm to 440nm to pass through, so that the light source will display a mixed color light of red light and green light (such as yellow light) after being reflected by the optical filter element 353. Light). If the light source is incident from one side of the filter structure 35, the other side of the filter structure 35 will display the colors corresponding to the respective optical filter elements 351-353, and at the incident end of the light source, all the aforementioned mixed color lights will be displayed. Mix again to display a nearly white monochromatic light.

Of course, in addition to being able to display the above three colors (red, green, blue), it is also possible to achieve the effect of displaying other colors such as yellow, cyan, or purple through the design of different materials and thicknesses of the reflective layer and the gap layer. . In addition, in addition to displaying three colors, three or more colors may be displayed.

The transflective liquid crystal display panel 1 of this embodiment is usually used in a display device with a backlight module. Please refer to FIGS. 7A-7B . FIG. 7A shows a cross-sectional view of the liquid crystal display device according to the present invention in reflective mode, and FIG. 7B shows a cross-sectional view of the liquid crystal display device in FIG. 7A in transmissive mode. The backlight module 410 of the liquid crystal display device 400 is disposed on the second substrate 33 side of the transflective liquid crystal display panel 3 , and three sub-pixel structures corresponding to the three optical filter elements 351 - 353 constitute, for example, a display pixel unit P. As shown in FIG. 7A , in the reflective mode, the backlight module 410 is turned off, and at this time, an external light source is projected onto the display panel 3 for display. Since the optical filter elements 351-353 have filtering effects such as selective penetration and reflection, after the external light source is incident on the second substrate 33 from the side of the first substrate 31, the optical filter elements 351-353 will filter the corresponding color light. In addition, at the same time, other colored lights are reflected. For example, corresponding to the optical filter element 351 reflecting cyan light Lc, the optical filter element 352 reflecting violet light Lm, and the optical filter element 353 reflecting yellow light Ly. Under the color mixing of the aforementioned three kinds of colored lights Lc, Lm, and Ly, what is displayed in the reflective mode is a nearly black-and-white monochromatic image.

As for the transmission mode (normal mode), as shown in FIG. 7B , the light source is provided by the backlight module 410 enclosed in the side of the second substrate 33, and the red light Lr, green light Lg, and blue light Lb in the light source will respectively pass through the corresponding optical The filter elements 351 - 353 adjust the ratio of red, green and blue in each pixel unit P by controlling the inclination of the liquid crystal molecules in the liquid crystal layer, thereby achieving the purpose of displaying a color picture.

In order to describe the effect of this embodiment in more detail, please refer to FIG. 8 again, which shows a cross-sectional view of the increased distance between the display panel and the backlight module in FIG. To illustrate. As shown in FIG. 8 , when the backlight L is projected, there will be green light Lg (as shown in FIG. 7B ) mixed with multi-band reflected light L1 or L2 (only reflected light in two path directions is shown). The reflected light L1 or L2 is reflected by the backlight module 210 and can be divided into two paths for reflection effect. The first path passes through the same optical filter element 352, and the second path passes through both sides of the optical filter element 352. The optical filter elements 351 and 353. Since the reflected light L1 or L2 contains red light, blue light and part of the green light, when the reflected light L1 is reflected in the first path, the gain effect of green light passing through will be produced again; when the reflected light L2 is reflected in the second path , then greatly increase the light utilization efficiency of red light and blue light. Similarly, when the light passes through other optical filter elements 351 , 353 etc. on the filter structure 35 , they also have the same effect. Therefore, under the reflection effect of the backlight module 210, enhanced red light Lr', green light Lg' and blue light Lb' are obtained. In addition, when the resolution of the display panel 3 is higher, since the size of the pixel structure P is smaller, the reuse rate of the reflected light L2 of the second path is higher.

The transflective liquid crystal display panel disclosed in the above embodiments of the present invention and the liquid crystal display device using it are provided with a filter structure on the substrate of the display panel. The filter structure has a plurality of optical filter elements for penetrating, Reflect light. According to the design of the material and thickness of the reflective layer and the gap layer in the optical filter element, the optical filter element can choose to transmit or reflect visible light with a specific bandwidth to achieve the effect of displaying a specific color. Due to the good penetration of the optical filter element, the color purity of the display screen is high. The backlight module of the liquid crystal display device is arranged on the side of the substrate with the light filtering structure. Through the reflection of the backlight in the backlight module, it can be further provided to other pixels on the display panel. The utilization rate of the backlight is good and energy consumption can be reduced.

In summary, although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Those skilled in the art to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall prevail as defined by the appended claims.

Claims (17)

1. semi-penetrated liquid crystal display panel comprises:

First substrate; And

Second substrate, and be gripped with liquid crystal layer between this first substrate, this second substrate comprises filtering structure, this filtering structure comprises a plurality of optical lightscreening elements, this optical lightscreening element makes the coloured light of at least three looks in the light source penetrate this filtering structure, this optical lightscreening element respectively comprises at least two reflection horizon and a clearance layer, and this clearance layer is between these two reflection horizon.

2. display panel as claimed in claim 1 wherein comprises a plurality of sub-pixel structures on this first substrate and this second substrate, respectively respectively this sub-pixel structure setting of this optical lightscreening element correspondence.

3. display panel as claimed in claim 1, wherein the material in these two reflection horizon comprises silver or silver alloy.

4. display panel as claimed in claim 1, wherein this clearance layer comprises dielectric layer or metallic conduction oxide.

5. display panel as claimed in claim 4, wherein the material of this dielectric layer comprises magnesium fluoride, silicon dioxide, aluminium oxide, titania, zirconium dioxide or niobium pentaoxide.

6. display panel as claimed in claim 4, wherein the material of this metallic conduction oxide comprises tin indium oxide, indium zinc oxide or aluminum zinc oxide.

7. display panel as claimed in claim 1, wherein these two reflection horizon other thickness is that about 5 nanometers are to 60 nanometers.

8. display panel as claimed in claim 1, wherein the thickness of this clearance layer is that about 10 nanometers are to 900 nanometers.

9. liquid crystal indicator comprises:

Semi-penetrated liquid crystal display panel comprises:

First substrate; And

Second substrate, be gripped with liquid crystal layer between this first substrate and this second substrate, this second substrate comprises filtering structure, this filtering structure comprises a plurality of optical lightscreening elements, this optical lightscreening element makes the coloured light of at least three looks in the light source penetrate this filtering structure, this optical lightscreening element respectively comprises at least two reflection horizon and a clearance layer, and this clearance layer is between these two reflection horizon; And

Backlight module is arranged at a side of this semi-penetrated liquid crystal display panel;

Wherein, when this backlight module was opened, the coloured light that belongs to this three look in its light source passed this optical lightscreening element with corresponding color respectively.

10. display device as claimed in claim 9 wherein comprises a plurality of sub-pixel structures on this first substrate and this second substrate, respectively respectively this sub-pixel structure setting of this optical lightscreening element correspondence.

11. display device as claimed in claim 9, wherein this backlight module is arranged at this second substrate-side.

12. display device as claimed in claim 9, wherein the material in these two reflection horizon comprises silver or silver alloy.

13. display device as claimed in claim 9, wherein this clearance layer comprises dielectric layer or metallic conduction oxide.

14. display device as claimed in claim 13, wherein the material of this dielectric layer comprises magnesium fluoride, silicon dioxide, aluminium oxide, titania, zirconium dioxide or niobium pentaoxide.

15. display device as claimed in claim 13, wherein the material of this metallic conduction oxide comprises tin indium oxide, indium zinc oxide or aluminum zinc oxide.

16. display panel as claimed in claim 9, wherein these two reflection horizon other thickness is that about 5 nanometers are to 60 nanometers.

17. display panel as claimed in claim 9, wherein the thickness of this clearance layer is that about 10 nanometers are to 900 nanometers.

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