CN101038397B - LCD module - Google Patents

Abstract

A liquid crystal display module comprises a backlight module and a liquid crystal display panel. The backlight module is suitable for emitting at least a first color light, a second color light and a third color light, wherein the wavelength range of the first color light is between 450nm and 460nm, the wavelength range of the second color light is between 520nm and 540nm, and the wavelength range of the third color light is between 610nm and 630 nm. The liquid crystal display panel comprises a color filter substrate, an active element array substrate and a liquid crystal layer, wherein the color filter substrate is provided with at least a first filter layer, a second filter layer and a third filter layer which are suitable for enabling the three color lights to pass through respectively. The peak value of the transmission spectrum of the second filter layer is between 520nm and 540nm, and the half-power bandwidth of the transmission spectrum of the second filter layer is between 90nm and 120nm, so that the NTSC ratio displayed by the liquid crystal display module is between 72% and 90%.

Description

LCD module

technical field

The invention relates to a liquid crystal display module, in particular to a liquid crystal display module which can effectively improve the brightness of a liquid crystal display panel.

Background technique

Liquid crystal displays have advantages that cannot be achieved by displays made of traditional cathode ray tubes (Cathode Ray Tube, CRT) due to their low-voltage operation, no radiation scattering, light weight, and small size. Compared with other flat-panel displays, such as plasma ( Plasma) displays and Electroluminance (EL) displays have become the main subjects of display research in recent years, and are even regarded as the mainstream of displays in the 21st century.

The existing liquid crystal display includes a backlight module (Backlight Module) and a liquid crystal display panel (Liquid Crystal Display Panel). Wherein, the backlight module has a light source device, which includes light emitting diodes (Light Emitting Diodes) that can respectively emit red, green and blue lights. In addition, the liquid crystal display panel uses the above-mentioned three-color light as a display light source to display images. The liquid crystal display panel includes a color filter substrate (Color Filter), an active device array substrate (Active Device Array Substrate) and a liquid crystal layer (Liquid Crystal Layer) , and the liquid crystal layer is disposed between the color filter substrate and the active element array substrate.

The display principle of the existing liquid crystal display is as follows. When the light source device of the backlight module emits light, the light first passes through an active element array substrate. The active element array substrate receives external signals and controls the voltage of each pixel electrode (Pixel Electrode) on it, so that the liquid crystal molecules in the liquid crystal layer show different arrangements, and the arrangement of the liquid crystal molecules can determine the light passing through the liquid crystal layer. Intensity size. If the light passing through a certain pixel electrode can smoothly pass through the liquid crystal layer under the control of the voltage of the pixel electrode, the light is finally filtered by the color filter substrate to display colors on the liquid crystal display panel.

Please refer to FIG. 1 , which shows a schematic diagram of a light emission spectrum of a light-emitting diode and a transmission spectrum of a color filter substrate in a conventional liquid crystal display. In Fig. 1, "LCFR" represents the transmission spectrum curve of a low-purity red filter layer in an existing color filter substrate, "LCFG" represents the transmission spectrum curve of a low-purity green filter layer, and "LCFB" represents a low-purity The transmission spectrum curve of the blue filter layer. In addition, "LEDR" represents the spectral curve of a red light-emitting diode, "LEDG" represents the spectral curve of a green light-emitting diode, and "LEDB" represents the spectral curve of a blue light-emitting diode. Generally speaking, under the action of the low-purity color filter substrate, the intensity or transmittance of light penetrating the color filter substrate is relatively high. In addition to passing the light emitted by the light-emitting diode, because its transmission spectrum is more likely to partially overlap with the light-emitting spectrum of the light-emitting diode of other colors, the light emitted by the light-emitting diode of other colors may also exit through the filter layer (at a low The transmission spectrum curve LCFG of the pure green filter layer is taken as an example, and its bandwidth overlaps with LEDB and LEDR), which makes the light filtering effect of the light emitted by the light emitting diode after passing through the color filter substrate not good.

Please refer to Figure 1, "HCFR" in Figure 1 represents the transmission spectrum curve of the high-purity red filter layer in another existing color filter substrate, "HCFG" represents the transmission spectrum curve of the high-purity green filter layer, " HCFB" indicates the transmission spectrum curve of the high-purity blue filter layer. In order to improve the above-mentioned poor filtering effect, the purity of the three primary color filter layers of the existing color filter substrate is increased, so that the bandwidth of the transmission spectrum of the high-purity color filter substrate and the bandwidth of the emission spectrum of the light-emitting diode are no longer as above. Partially overlapping, thus improving the filtering effect of the color filter substrate. In addition, please refer to FIG. 2 , which shows a CIE Chromaticity Diagram (CIE Chromaticity Diagram) of an existing color filter substrate of a liquid crystal display. As can be seen from Figure 2, improving the purity of the three primary color filter layers of the color filter substrate (the purity of the code-named HCF in Figure 2 is greater than the purity of the code-named LCF) will make the NTSC (National Television System Committee) ratio (or display color gamut) of the liquid crystal display ) increase.

From the above, it can be seen that in the current technology, the filter layers of the color filter substrate are mostly developed towards high purity, so as to improve the color purity of the liquid crystal display, and further obtain a preferred image quality. However, as the purity of the filter layer of the color filter substrate increases, the manufacturing cost increases, the light transmittance of the color filter substrate decreases, and the display brightness of the liquid crystal display decreases. It is worth mentioning that the NTSC ratio displayed by CRT monitors in the past is usually maintained at around 75%, but such a display effect is sufficient to meet the needs of ordinary users. In other words, at present, the design direction of high color purity and high display quality is constantly moving, although the production cost is greatly increased, but the relative benefit that it can improve is quite limited.

Contents of the invention

In view of this, the purpose of the present invention is to provide a liquid crystal display module, which adjusts the purity of the filter layer of the color filter substrate under the premise of maintaining a certain degree of display quality, in order to increase the penetration of the filter layer rate, thereby improving the overall brightness of the LCD panel.

Based on the above objective or other objectives, the present invention provides a liquid crystal display module, which includes a backlight module and a liquid crystal display panel. Wherein, the backlight module has a light source device for emitting at least a first color light, a second color light and a third color light, wherein the wavelength range of the first color light is between 450nm and 460nm, and the wavelength of the second color light The range is between 520nm and 540nm, and the wavelength range of the third color light is between 610nm and 630nm. In addition, the liquid crystal display panel uses the first color light, the second color light and the third color light as display light sources to display images, wherein the liquid crystal display panel includes a color filter substrate, an active element array substrate and a liquid crystal layer. The color filter substrate has at least a first filter layer, a second filter layer and a third filter layer, wherein the first filter layer is suitable for passing the first color light, and the second filter layer is suitable for allowing The second color light passes, and the third filter layer is suitable for passing the third color light. The active element array substrate is opposite to the color filter substrate, and the liquid crystal layer is arranged between the color filter substrate and the active element array substrate. In the present invention, the peak value of the transmission spectrum of the second filter layer is between 520nm and 540nm, and the half power bandwidth (FWHM) of the transmission spectrum of the second filter layer is between 90nm and 120nm, so that the liquid crystal The display module shows an NTSC ratio between 72% and 90%.

According to a preferred embodiment of the present invention, the above-mentioned light source device includes at least one first light emitting diode, at least one second light emitting diode and at least one third light emitting diode for emitting the first color light, the second color light and the Tertiary shade.

According to a preferred embodiment of the present invention, the above-mentioned active element array substrate is, for example, a thin film transistor array substrate (Thin Film Transistor Array Substrate). The thin film transistor array substrate includes, for example, a transparent substrate, a plurality of scan lines and data lines, a plurality of thin film transistors and a plurality of pixel electrodes. Wherein, the scanning lines and the data wirings are arranged on the transparent substrate to distinguish a plurality of pixel areas. In addition, the thin film transistors are respectively arranged in the pixel area, so as to be driven by corresponding scanning lines and data wirings. In addition, the pixel electrodes are respectively arranged in the pixel area and coupled to the corresponding thin film transistors.

According to a preferred embodiment of the present invention, the peak value of the transmission spectrum of the above-mentioned first filter layer is, for example, between 440 nm and 460 nm.

According to a preferred embodiment of the present invention, the half power bandwidth (FWHM) of the transmission spectrum of the above-mentioned first filter layer is, for example, between 60 nm and 110 nm.

According to a preferred embodiment of the present invention, the peak value of the transmission spectrum of the third filter layer is, for example, between 610 nm and 630 nm.

According to a preferred embodiment of the present invention, the half power bandwidth (FWHM) of the transmission spectrum of the third filter layer is, for example, between 100 nm and 180 nm.

According to a preferred embodiment of the present invention, the film thickness of the above-mentioned first filter layer is, for example, between 1.0 μm and 1.8 μm.

According to a preferred embodiment of the present invention, the film thickness of the above-mentioned second filter layer is, for example, between 1.0 μm and 2.0 μm.

According to a preferred embodiment of the present invention, the film thickness of the third filter layer is, for example, between 1.0 μm and 2.0 μm.

Based on the above, under the premise that the NTSC ratio displayed by the liquid crystal display module is maintained between 72% and 90%, the light filter on the color filter substrate is adjusted according to the wavelength range of the three-color light emitted by the backlight module. The purity of the layer can increase the transmittance of the filter layer, thereby improving the overall brightness of the liquid crystal display panel.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, the present invention will be described in more detail below with reference to the accompanying drawings and preferred embodiments.

Description of drawings

FIG. 1 shows a schematic diagram of a light emission spectrum of a light-emitting diode and a transmission spectrum of a color filter substrate in a conventional liquid crystal display.

FIG. 2 shows a CIE chromaticity diagram of a conventional liquid crystal display color filter substrate.

FIG. 3 is a schematic perspective view of a liquid crystal display module according to a preferred embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating the emission spectrum of the LED and the transmission spectrum of the color filter substrate in FIG. 3 .

FIG. 5 shows a CIE chromaticity diagram of the color filter substrate of FIG. 3 .

simple notation

LCF: Display color gamut of an existing low-purity color filter substrate

LCFR: The transmission spectrum curve of a low-purity red filter layer in an existing color filter substrate

LCFG: The transmission spectrum curve of a low-purity green filter layer in an existing color filter substrate

LCFB: The transmission spectrum curve of a low-purity blue filter layer in an existing color filter substrate

HCF: Display color gamut of another high-purity color filter substrate

HCFR: The transmission spectrum curve of the high-purity red filter layer in another color filter substrate

HCFG: The transmission spectrum curve of a high-purity green filter layer in another color filter substrate

HCFB: The transmission spectrum curve of a high-purity blue filter layer in another color filter substrate

LEDR: Spectral Curve of Existing Red Light Emitting Diodes

LEDG: Spectral Curves of Existing Green Light Emitting Diodes

LEDB: Spectral Curve of Existing Blue Light Emitting Diodes

100: LCD module

110: Backlight module

112: light source device

112a: first light emitting diode

112b: second light emitting diode

112c: third light emitting diode

120: LCD display panel

122: Color filter substrate

122a: first filter layer

122b: second filter layer

122c: the third filter layer

124: Active element array substrate

124a: Transparent substrate

124b: scan line

124c: data line

124d: thin film transistor

124e: pixel electrode

124f: pixel area

126: liquid crystal layer

LCF': the display color gamut of a low-purity color filter substrate of the present invention

LCFR': the transmission spectrum curve of the third filter layer of the present invention

LCFG': the transmission spectrum curve of the second filter layer of the present invention

LCFB': the transmission spectrum curve of the first filter layer of the present invention

LEDR': the spectral curve of the third color light emitted by the light source device of the present invention

LEDG': the spectral curve of the second color light emitted by the light source device of the present invention

LEDB': the spectral curve of the first color light emitted by the light source device of the present invention

P1: the peak value of the transmission spectrum curve of the first filter layer of the present invention

P2: the peak value of the transmission spectrum curve of the second filter layer of the present invention

P3: the peak value of the transmission spectrum curve of the third filter layer of the present invention

W1: the half-power bandwidth of the transmission spectrum curve of the first filter layer of the present invention

W2: the half-power bandwidth of the transmission spectrum curve of the second filter layer of the present invention

W3: the half-power bandwidth of the transmission spectrum curve of the third filter layer of the present invention

Detailed ways

Please refer to FIG. 3 , which is a schematic perspective view of a liquid crystal display module according to a preferred embodiment of the present invention. The liquid crystal display module 100 of this embodiment includes a backlight module 110 and a liquid crystal display panel 120 . Wherein, the backlight module 110 has a light source device 112 for emitting at least a first color light, a second color light and a third color light, wherein the wavelength range of the first color light is between 450nm and 460nm (such as blue light ), the wavelength range of the second color light is between 520nm and 540nm (for example, green light), and the wavelength range of the third color light is between 610nm and 630nm (for example, red light).

The light source device 112 includes, for example, at least one first LED 112a, at least one second LED 112b and at least one third LED 112c, which are used to emit the above-mentioned first color light, second color light and third color light respectively. In addition, the liquid crystal display panel 120 is disposed above the backlight module 110 to receive the first color light, the second color light and the third color light as light sources for display. In this embodiment, the liquid crystal display panel 120 includes, for example, a color filter substrate 122 , an active element array substrate 124 and a liquid crystal layer 126 . Wherein, the color filter substrate 122 has at least a first filter layer 122a, a second filter layer 122b and a third filter layer 122c, wherein the first filter layer 122a is suitable for passing the first color light, and the second filter layer The second filter layer 122b is suitable for passing the second color light, and the third filter layer 122c is suitable for passing the third color light. In addition, the active element array substrate 124 is opposite to the color filter substrate 122 , and the liquid crystal layer 126 is disposed between the color filter substrate 122 and the active element array substrate 124 .

Please refer to FIG. 3 again, the active element array substrate 124 is, for example, a thin film transistor array substrate. The thin film transistor array substrate includes, for example, a transparent substrate 124a, a plurality of scan lines 124b and data lines 124c, a plurality of thin film transistors 124d and a plurality of pixel electrodes 124e. Wherein, the scan lines 124b and the data lines 124c are arranged on the transparent substrate 124a to distinguish a plurality of pixel areas 124f. In addition, the thin film transistors 124d are respectively disposed in the pixel regions 124f to be driven by the scan lines 124b and the data lines 124c. In addition, the pixel electrodes 124e are respectively disposed in the pixel regions 124f and coupled to the corresponding thin film transistors 124d, and the material of the pixel electrodes 124e is transparent conductive material such as indium tin oxide (ITO).

The display principle of the liquid crystal display module 100 of this embodiment is as follows. The above-mentioned three-color lights emitted by the light source device 112 of the backlight module 110 are directed toward the liquid crystal display panel 120 through the structural design of the backlight module 110 . The thin film transistor 124b on the active element array substrate 124 is driven by the scanning wiring 124b and the data wiring 124c, and controls the voltage of each pixel electrode 124e on it, so that the liquid crystal molecules of the liquid crystal layer 126 (not shown in FIG. ) present different arrangements, and the intensity of light passing through the liquid crystal layer 126 can be determined according to the arrangement of the liquid crystal molecules. If the light passing through a certain pixel electrode 124e can smoothly pass through the liquid crystal layer 126 under the control of the voltage of the pixel electrode 124e, the light is finally filtered by the color filter substrate 122 to display colors on the liquid crystal display panel 120 .

FIG. 4 is a schematic diagram of the light emission spectrum of the LED and the transmission spectrum of the color filter substrate in FIG. 3 , and FIG. 5 is a CIE chromaticity diagram of the color filter substrate in FIG. 3 . In order to solve the aforementioned problems of the existing liquid crystal display, this embodiment reduces the purity of the filter layer on the color filter substrate 122 according to the wavelength range of the three-color light emitted by the backlight module 110, so as to increase the transmittance of the filter layer . Please refer to FIGS. 3 to 5 at the same time. In FIG. 4, "LEDB'", "LEDG'" and "LEDR'" respectively represent the first color light, the second color light and the third color light emitted by the light source device 112 in this embodiment. the spectral curve. In order to make the NTSC ratio displayed by the liquid crystal display module 100 (the overlapping area of the range covered by LCF' and the range covered by NTSC in FIG. 5 divided by the area covered by NTSC) be between 72% and 90%, for example, the The material selection of the second filter layer 122b or the control of the film thickness (between 1.0 μm and 2.0 μm) make the peak P2 of the transmission spectrum LCFG′ of the second filter layer 122b between 520nm and 540nm, and The half power bandwidth (FWHM) W2 of the transmission spectrum LCFG' of the second filter layer 122b is between 90nm and 120nm.

It should be noted that, in addition to the setting of the peak value P2 and the half-power bandwidth W2 of the transmission spectrum LCFG' of the second filter layer 122b, the choice of material or film thickness of the first filter layer 122a can also be matched in the same way. (between 1.0 μm and 1.8 μm), so that the peak P1 of the transmission spectrum LCFB' of the first filter layer 122a is between 440nm and 460nm, and the transmission spectrum LCFB' of the first filter layer 122a The half-power bandwidth (FWHM) W1 is between 60nm and 110nm. In addition, the selection of the material of the third filter layer 122c or the control of the film thickness (between 1.0 μm and 2.0 μm) can also be used, so that the peak P3 of the transmission spectrum LCFR’ of the third filter layer 122c is between 610 nm between 100 nm and 630 nm, and make the half power bandwidth (FWHM) W3 of the transmission spectrum LCFR' of the third filter layer 122 c between 100 nm and 180 nm. Therefore, through the above-mentioned design method, the filter purity of the color filter substrate for different colors of light can be effectively adjusted to achieve the NTSC ratio designed to be displayed by the liquid crystal display module 100 .

To sum up, the present invention maintains the display color purity of the liquid crystal display within a specific range (NTSC ratio between 72% and 90%), rather than developing towards high-purity color display without limitation. Among them, according to the wavelength range of the three-color light emitted by the backlight module, through the selection of the material of the filter layer or the control of the film thickness, the peak value and half-power bandwidth of the transmission spectrum of the filter layer are adjusted to increase the filter layer. penetration rate. Therefore, the manufacturing cost of the color filter substrate can be effectively reduced, which is conducive to the mass production of products, and the film thickness of the filter layer can be reduced to improve the overall display brightness.

Although the present invention is disclosed above with preferred embodiments, it is not intended to limit the present invention. Those skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention It shall prevail as defined in the appended claims.

Claims (11)

1. A liquid crystal display module, comprising: The backlight module has a light source device for emitting at least one first color light, second color light and third color light, wherein the wavelength range of the first color light is between 450nm and 460nm, and the wavelength range of the second color light is between between 520nm and 540nm, and the wavelength range of the third color light is between 610nm and 630nm; The liquid crystal display panel uses the first color light, the second color light and the third color light as display light sources to display images, and the liquid crystal display panel includes: The color filter substrate has at least a first filter layer, a second filter layer and a third filter layer, wherein the first filter layer is suitable for passing the first color light, and the second filter layer is suitable for for passing the second color light, and the third filter layer is suitable for passing the third color light; an active element array substrate opposite to the color filter substrate; and The liquid crystal layer is arranged between the color filter substrate and the active element array substrate, the peak of the transmission spectrum of the second filter layer is between 520nm and 540nm, and the transmission spectrum of the second filter layer is The half-power bandwidth is between 90nm and 120nm, wherein the half-power bandwidth of the transmission spectrum of the first filter layer extends from a first wavelength to a second wavelength greater than the first wavelength, and wherein the transmission spectrum of the first filter layer is not at the second wavelength It overlaps with the wavelength range of the second color light. 2. The liquid crystal display module as claimed in claim 1, wherein the light source device comprises at least one first light emitting diode, at least one second light emitting diode and at least one third light emitting diode for respectively emitting the first color light, the The second color light and the third color light. 3. The liquid crystal display module as claimed in claim 1, wherein the active element array substrate is a thin film transistor array substrate. 4. The liquid crystal display module as claimed in claim 3, wherein the thin film transistor array substrate comprises: transparent substrate; A plurality of scanning lines and data wirings are arranged on the transparent substrate to distinguish a plurality of pixel areas; A plurality of thin film transistors are respectively arranged in the pixel areas to be driven by the scanning lines and the data wirings; and A plurality of pixel electrodes are respectively arranged in the pixel areas and coupled to the corresponding thin film transistors. 5. The liquid crystal display module as claimed in claim 1, wherein the peak value of the transmission spectrum of the first filter layer is between 440nm and 460nm. 6. The liquid crystal display module as claimed in claim 1, wherein the half-power bandwidth of the transmission spectrum of the first filter layer is between 60 nm and 110 nm. 7. The liquid crystal display module as claimed in claim 1, wherein the peak value of the transmission spectrum of the third filter layer is between 610nm and 630nm. 8. The liquid crystal display module as claimed in claim 1, wherein the half-power bandwidth of the transmission spectrum of the third filter layer is between 100 nm and 180 nm. 9. The liquid crystal display module as claimed in claim 1, wherein the film thickness of the first filter layer is between 1.0 μm and 1.8 μm. 10. The liquid crystal display module as claimed in claim 1, wherein the film thickness of the second filter layer is between 1.0 μm and 2.0 μm. 11. The liquid crystal display module as claimed in claim 1, wherein the film thickness of the third filter layer is between 1.0 μm and 2.0 μm.

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