TWI755099B - Electrically controlled color filter and display apparatus - Google Patents

Abstract

An electrically controlled color filter including a metal film, electro-optics material layer, two insulation layers and two electrode layers is provided. The metal film has a first surface and a second surface opposite to each other and a plurality of holes penetrating through the first surface and the surface. The electro-optics material layer is disposed in the holes of the metal film. The two insulation layers are respectively disposed on the first surface and the second surface of the metal film. The two electrodes are respectively disposed on opposite sides of the electro-optics material layer and the insulation layers are positioned between the electrode layers and the metal film. An electric field formed between the electrode layers is used to change the relative dielectric constant of the electro-optics material layer, so as to adjust the dominant wavelength of light incident on the metal film and passing through the holes. A display apparatus adopting the electrically controlled color filter is also provided.

Description

Electronically controlled color filter and display device

The present invention relates to a color filter and an electronic device, and more particularly, to an electronically controlled color filter and a display device.

Most of the existing display devices utilize the color mixing of three primary colors (ie, red, green and blue) to realize the color display of images. Conventional optical filters use pigment dispersions to filter light and produce the three primary colors used in display pixels, while complementary colors of light are absorbed and completely wasted. Most of these filters are formed through three separate processes, which not only complicates manufacturing, but also tends to waste chemicals in the process. That is, such an optical filter has a relatively low utilization rate of light energy, and at the same time significantly increases the overall cost of the display device. Furthermore, after the optical filter is manufactured, its filtering effect cannot be changed.

The invention provides an electronically controlled color filter, which has the ability to modulate the wavelength of penetrating light.

The present invention provides a display device with better controllability of color representation.

The electronically controlled color filter of the present invention comprises a metal thin film, an electro-optical material layer, two insulating layers and two electrode layers. The metal thin film has opposite first and second surfaces and a plurality of holes penetrating through the first and second surfaces. The holes are respectively arranged at a distance in the first direction and the second direction intersecting with each other. The electro-optic material layer is arranged in the holes of the metal thin film. The two insulating layers are respectively disposed on the first surface and the second surface of the metal thin film. The two electrode layers are respectively disposed on opposite sides of the electro-optic material layer, and the insulating layers are located between the electrode layers and the metal thin film. The electric field formed between these electrode layers is used to change the relative permittivity of the electro-optic material layer to adjust the dominant wavelength of light incident on the metal thin film and passing through the holes.

The display device of the present invention includes a backlight module and an electronically controlled color filter. The backlight module has a circuit substrate and a plurality of light-emitting elements arranged on the circuit substrate. The electronically controlled color filter is arranged on the side of the backlight module where the light-emitting elements are arranged, and includes a metal thin film, an electro-optical material layer, two insulating layers and two electrode layers. The metal thin film has opposite first and second surfaces and a plurality of holes penetrating through the first and second surfaces. The holes are respectively arranged at a distance in the first direction and the second direction intersecting with each other. The electro-optic material layer is arranged in the holes of the metal thin film. The two insulating layers are respectively disposed on the first surface and the second surface of the metal thin film. The two electrode layers are respectively disposed on opposite sides of the electro-optic material layer, and the insulating layers are located between the electrode layers and the metal thin film. The electric field formed between these electrode layers is used to change the relative permittivity of the electro-optic material layer to adjust the dominant wavelength of light incident on the metal thin film and passing through the holes.

Based on the above, in the display device according to an embodiment of the present invention, the electronically controlled color filter utilizes an electric field to control the relative permittivity of the electro-optic material layer located in the holes of the metal thin film, so as to adjust the relative permittivity of the electro-optic material layer through the holes. The dominant wavelength of light. That is to say, the above-mentioned electronically controlled color filter has the ability to modulate the wavelength of the transmitted light, thereby improving the controllability of the color representation of the display device.

The foregoing and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front or rear, etc., are only for referring to the directions of the attached drawings. Accordingly, the directional terms used are illustrative and not limiting of the present invention.

FIG. 1 is a schematic cross-sectional view of a display device according to an embodiment of the present invention. FIG. 2 is a schematic top view of the display device of FIG. 1 . It is particularly noted that, for the sake of clarity, the circuit substrate 110 , the substrate 210 , the insulating layer 231 , the insulating layer 232 and the electrode layer 241 in FIG. 1 are omitted in FIG. 2 .

Please refer to FIG. 1 and FIG. 2 , the display device 10 includes a backlight module 100 and an electronically controlled color filter 200 . The backlight module 100 includes a circuit substrate 110 and a plurality of light emitting elements 120 . The light-emitting elements 120 are disposed on the circuit substrate 110 and are electrically connected to the circuit substrate 110 . For example, the circuit substrate 110 may include a pixel circuit layer, and the pixel circuit layer is suitable for independently controlling the respective light-emitting luminances of the light-emitting elements 120 , but not limited thereto. The electronically controlled color filter 200 is disposed on the side of the backlight module 100 where the plurality of light emitting elements 120 are arranged, and in the stacking direction (eg, the direction Z) of the backlight module 100 and the electronically controlled color filter 200 . It overlaps with these light-emitting elements 120 . The light emitting element 120 is adapted to emit light LB toward the electronically controlled color filter 200 , and the dominant wavelength of the light LB will be changed after passing through the electronically controlled color filter 200 .

For example, in this embodiment, the backlight module 100 may be a micro light emitting diode panel, that is, the light emitting element 120 may be a micro light emitting diode (micro-LED). However, the present invention is not limited to this. In an embodiment not shown, the backlight module can also be a sub-millimeter light emitting diode (mini light emitting diode, mini-LED) panel or an organic light emitting diode (organic light emitting diode). emitting diode, OLED) panel. It should be noted that, in another embodiment not shown, a liquid crystal layer may also be provided between the backlight module 100 of the display device and the electronically controlled color filter 200 to modulate the light emitted by the light-emitting element 120 . The light intensity of the light. That is to say, the present invention can also be applied to a display device equipped with a non-self-luminous display medium, and the backlight module 100 can be used as a backlight source of the non-self-luminous display medium.

Further, the electronically controlled color filter 200 includes a substrate 210 , a metal thin film 220 and an electro-optical material layer 225 . The material of the substrate 210 is a light-transmitting material, such as quartz, glass, or other suitable polymer materials. In this embodiment, the relative dielectric constant of the metal thin film 220 is in the range of -8.69 to -12.94. Specifically, the relative permittivity here is defined by the ratio of the real part of the complex permittivity of the metal thin film 220 to the vacuum permittivity.

The metal film 220 has a first surface 220s1, a second surface 220s2 and a plurality of holes 220h. The first surface 220s1 is opposite to the second surface 220s2 and is penetrated by the holes 220h. In this embodiment, the holes 220h are arranged in the direction X and the direction Y respectively, wherein the direction X is perpendicular to the direction Y. As shown in FIG. More specifically, the holes 220h in this embodiment are arrayed on the metal thin film 220 in a square lattice manner, but not limited thereto.

In this embodiment, the vertical projection profiles of the holes 220h of the metal film 220 on the first surface 220s1 are all circular, and the diameter Da of the holes 220h may be between 40 nm and 80 nm. On the other hand, the plurality of holes 220h in the present embodiment are arranged periodically with a distance d in the directions X and Y, and the distance d is less than 400 nm, for example, 240 nm. It should be noted that the distance d here is defined by the distance between the geometric centers of the two adjacent holes 220h in the direction X or the direction Y, but is not limited thereto.

The electro-optic material layer 225 is disposed in the holes 220h of the metal thin film 220 . For example, the electro-optic material layer 225 includes a plurality of liquid crystal molecules (not shown). In order to drive the liquid crystal molecules to rotate so that the relative permittivity of the electro-optic material layer 225 is adjusted to a desired value, the electronically controlled color filter 200 further includes an insulating layer 231 , an insulating layer 232 , an electrode layer 241 and an electrode layer 242 . The insulating layer 231 and the insulating layer 232 are respectively disposed on the first surface 220s1 and the second surface 220s2 of the metal thin film 220 . The electrode layer 241 and the electrode layer 242 are respectively disposed on opposite sides of the electro-optic material layer 225 .

More specifically, the electronically controlled color filter 200 uses the electric field formed between the electrode layer 241 and the electrode layer 242 to control the optical axis of the liquid crystal molecules, so that the relative permittivity of the electro-optic material layer 225 can be within Modulation in the range of 3.4 to 8.33, thereby adjusting the dominant wavelength (dominant wavelength) of the light LB passing through these holes 220h. Further, the second surface 220s2 of the metal thin film 220 can generate a surface plasmon resonance phenomenon after being irradiated by the light LB from the light emitting element 120, and is transmitted from the metal thin film through the plurality of holes 220h. One side of the first surface 220s1 of 220 emits light having a specific wavelength (eg, visible light wavelength).

The dominant wavelength of the light LB emitted by the light-emitting element 120 that can excite the surface plasmon resonance depends on the absolute difference between the relative permittivity of the metal thin film 220 and the electro-optic material layer 225 and the arrangement period of the plurality of holes 220h (ie, the distance d). For example, when the absolute difference between the relative permittivity of the metal thin film 220 and the electro-optic material layer 225 is smaller, the dominant wavelength of light that can pass through the holes 220h will be red-shifted (that is, the dominant wavelength increases with the relative permittivity). The smaller the absolute difference is, the more it increases).

In this embodiment, the electrode layer 242 has a plurality of electrode patterns 242P separated from each other, and the electrode patterns 242P are respectively overlapped with the plurality of light emitting elements 120 of the backlight module 100 . However, the present invention is not limited to this, and in other embodiments not shown, the plurality of electrode patterns can also be formed by another electrode layer 241 or two electrode layers 241 and 242 . The electrode layer 241 and the electrode layer 242 are light-transmitting electrodes, and the material of the light-transmitting electrodes includes metal oxides, such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, or Other suitable oxides, or a stack of at least two of the above. The material of the insulating layer 231 and the insulating layer 232 includes, for example, silicon oxide, silicon nitride or oxynitride.

It should be noted that the plurality of electrode patterns 242P of the electrode layer 242 may define a plurality of pixel areas (eg, the pixel area PA1 , the pixel area PA2 and the pixel area PA3 ) of the display device 10 . Through these electrically independent electrode patterns 242P, the dominant wavelength of the light LB emitted by the light emitting elements 120 located in different pixel regions can be individually controlled after passing through the corresponding array of holes 220h.

For example, the three parts of the electro-optic material layer 225 overlapping the pixel area PA1 , the pixel area PA2 and the pixel area PA3 respectively have relative dielectrics of 3.4, 4.76 and 6.26 under the driving of the corresponding three electrode patterns 242P. Electric constant. At this time, the light LB1 , the light LB2 and the light LB3 emitted by the three light-emitting elements 120 located in the pixel area PA1 , the pixel area PA2 and the pixel area PA3 respectively pass through the above-mentioned three parts in the electro-optic material layer 225 , respectively. , whose dominant wavelengths are about 400 nm, 550 nm, and 800 nm, respectively. That is, the light LB1 , the light LB2 and the light LB3 respectively form blue light, green light and red light after passing through the electronically controlled color filter 200 (or the array of holes 220h of the metal film 220 ). By mixing the three colors of light with different light intensity ratios, display effects of different gray scales or/and different chromaticities can be achieved.

It is worth mentioning that, in this embodiment, the light LB emitted by each light-emitting element 120 has the same dominant wavelength (for example, 480 nm) before entering the electronically controlled color filter 200 , but it is not limited. That is to say, the electronically controllable color filter 200 has the ability to modulate the wavelength of the transmitted light, thereby improving the controllability of the color representation of the display device 10 .

It should be noted that, in this embodiment, the number of holes 220h and the number of light-emitting elements 120 overlapped by each pixel area (eg, pixel area PA1 or pixel area PA2 ) are respectively nine and one for exemplary purposes. but it does not mean that the present invention is limited by this. In other embodiments, the number of holes 220h overlapping each pixel region and the number of light-emitting elements 120 can also be adjusted according to actual design requirements or product specifications. For example, the number of holes 220h can also be more than twelve or sixteen. The number of light-emitting elements 120 may be two or more.

Hereinafter, other embodiments will be listed to describe the present disclosure in detail, wherein the same components will be marked with the same symbols, and the description of the same technical content will be omitted.

FIG. 3 is a schematic cross-sectional view of a display device according to another embodiment of the present invention. Referring to FIG. 3 , the difference between the display device 11 of the present embodiment and the display device 10 of FIG. 1 is that the configuration of the light-emitting elements of the backlight module is different. Specifically, the backlight module 100A of the display device 11 includes a first light-emitting element 121 , a second light-emitting element 122 and a third light-emitting element 123 which are alternately arranged on the circuit substrate 110 , and the first light-emitting element 121 and the second light-emitting element 121 The dominant wavelengths of light emitted by the light emitting element 122 and the third light emitting element 123 are different from each other.

For example, in this embodiment, the dominant wavelengths of the light LB1 , the light LB2 and the light LB3 emitted by the first light emitting element 121 , the second light emitting element 122 and the third light emitting element 123 are 480 nm and 530 nm respectively. meters and 550 nm. Therefore, the relative dielectric constants of the metal thin film 220 at the dominant wavelengths of 480 nm, 530 nm and 550 nm are -8.69, -11.63 and -12.94, respectively. On the other hand, the three parts of the electro-optic material layer 225 overlapping the pixel area PA1 , the pixel area PA2 and the pixel area PA3 respectively have relative distances of 3.4, 5.53 and 8.19 under the driving of the corresponding three electrode patterns 242P. The electrical constant (the relative permittivity here is the relative permittivity of the three parts of the electro-optic material layer 225).

In this embodiment, the light LB1 , the light LB2 and the light LB3 emitted by the three light emitting elements 120 located in the pixel area PA1 , the pixel area PA2 and the pixel area PA3 respectively pass through the electro-optic material layer 225 corresponding to the above-mentioned After the three parts, the dominant wavelengths are about 400 nm, 550 nm and 800 nm, respectively. That is, the light LB1 , the light LB2 and the light LB3 respectively form blue light, green light and red light after passing through the electronically controlled color filter 200 (or the array of holes 220h of the metal film 220 ). By mixing the three colors of light with different light intensity ratios, display effects of different gray scales or/and different chromaticities can be achieved.

To sum up, in the display device according to an embodiment of the present invention, the electronically controlled color filter uses an electric field to control the relative permittivity of the electro-optical material layer located in the holes of the metal thin film, so as to adjust the relative permittivity of the electro-optical material layers through the holes of the metal thin film. The dominant wavelength of light from the hole. That is to say, the above-mentioned electronically controlled color filter has the ability to modulate the wavelength of the transmitted light, thereby improving the controllability of the color representation of the display device.

10, 11: Display device 100, 100A: Backlight module 110: circuit substrate 120, 121, 122, 123: Light-emitting elements 200: Electronically controlled color filter 210: Substrate 220: Metal Thin Film 220h: Hole 220s1: First Surface 220s2: Second Surface 225: Electro-optical material layer 231, 232: insulating layer 241, 242: electrode layer 242P: Electrode Pattern d: distance Da: aperture LB, LB1, LB2, LB3: Light PA1, PA2, PA3: pixel area X, Y, Z: direction

FIG. 1 is a schematic cross-sectional view of a display device according to an embodiment of the present invention. FIG. 2 is a schematic top view of the display device of FIG. 1 . FIG. 3 is a schematic cross-sectional view of a display device according to another embodiment of the present invention.

10: Display device

100: Backlight module

110: circuit substrate

120: Light-emitting element

200: Electronically controlled color filter

210: Substrate

220: Metal Thin Film

220h: Hole

220s1: First Surface

220s2: Second Surface

225: Electro-optical material layer

231, 232: insulating layer

241, 242: electrode layer

242P: Electrode Pattern

LB, LB1, LB2, LB3: Light

PA1, PA2, PA3: pixel area

X, Y, Z: direction

Claims (11)

An electronically controlled color filter, comprising: a metal film having a first surface and a second surface opposite to each other and a plurality of holes penetrating the first surface and the second surface, the holes intersecting each other respectively A first direction and a second direction are arranged at a distance; an electro-optic material layer is arranged in the holes of the metal film; two insulating layers are respectively arranged on the first surface and the first surface of the metal film on two surfaces; and two electrode layers, respectively disposed on opposite sides of the electro-optic material layer, and the insulating layers are located between the electrode layers and the metal thin film, wherein an electric field is formed between the electrode layers It is used to change the relative dielectric constant of the electro-optic material layer to adjust the dominant wavelength of a light incident on the metal thin film and passing through the holes. The electronically controlled color filter of claim 1, wherein the relative permittivity of the metal thin film is in the range of -8.69 to -12.94. The electronically controlled color filter of claim 1, wherein the relative permittivity of the electro-optic material layer is in the range of 3.4 to 8.33. The electronically controlled color filter of claim 1, wherein the apertures of the holes are between 40 nanometers and 80 nanometers. The electronically controlled color filter of claim 1, wherein the first direction is perpendicular to the second direction. A display device, comprising: a backlight module having a circuit substrate and a plurality of a light-emitting element; and an electronically controlled color filter disposed on the side of the backlight module where the light-emitting elements are disposed, the electronically controlled color filter comprising: a metal film having an opposite first a surface and a second surface and a plurality of holes passing through the first surface and the second surface, the holes are arranged in a first direction and a second direction intersecting with each other and spaced apart from each other by a distance; an electro-optical material layer, disposed in the holes of the metal film; two insulating layers, respectively disposed on the first surface and the second surface of the metal film; and two electrode layers, respectively disposed on the opposite two sides of the electro-optic material layer side, and the insulating layers are located between the electrode layers and the metal film, wherein an electric field formed between the electrode layers is used to change the relative permittivity of the electro-optic material layer to adjust the incident metal film and the dominant wavelength of a light passing through the holes. The display device of claim 6, wherein one of the electrode layers has a plurality of electrode patterns separated from each other, and the electrode patterns overlap the light-emitting elements respectively. The display device of claim 7, wherein the light-emitting elements comprise a first light-emitting element, a second light-emitting element and a third light-emitting element which are alternately arranged, and the first light-emitting element, the second light-emitting element and The dominant wavelengths of the light rays emitted by the third light emitting elements are different from each other. The display device of claim 6, wherein the relative permittivity of the metal thin film is in the range of -8.69 to -12.94. The display device of claim 6, wherein the relative permittivity of the electro-optic material layer is in the range of 3.4 to 8.33. The display device of claim 6, wherein the apertures of the holes are between 40 nanometers and 80 nanometers.

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