CN101699343B - Electrophoretic display pixel and display device - Google Patents

Abstract

The invention discloses an electrophoretic display pixel, which includes an electrophoretic display film, a substrate, a first active element, a second active element, a first electrode and a second electrode. The substrate is arranged on the electrophoretic display film and has a light-transmitting area and a non-light-transmitting area. Both the first active element and the second active element are disposed on the substrate and located in the non-transmissive area. The first electrode is arranged on the substrate, located in the light-transmitting area, and electrically connected to the first active element, while the second electrode is arranged on the substrate, located in the non-light-transmitting area, and electrically connected to the second active element. A light passes through the light-transmitting region and enters the electrophoretic display film for display. A display device including the above-mentioned electrophoretic display pixel is also proposed.

Description

Electrophoretic display pixel and display device

technical field

The invention relates to an electrophoretic display pixel and a display device, and in particular to an electrophoretic display pixel and a display device with high display contrast.

Background technique

While developing flat-panel displays, lighter, thinner, and flexible features have always been the main goals of future displays in the market. The display technologies used in this type of flexible display, e-paper and e-book include liquid crystal display technology, electrophoretic display technology and electrochromic color rendering technology.

The electrophoretic display includes an active element array substrate and an electrophoretic display film attached to the active element array substrate. The electrophoretic display film has a display matrix and a plurality of display particles distributed in the display matrix. The display matrix is, for example, a display solution, while the display particles are particles with positive or negative polarity. The active device array substrate includes a plurality of pixel structures composed of an active device and a pixel electrode.

The user usually watches from the side close to the electrophoretic display film and away from the active device array substrate, that is to say, the side of the active device array substrate is the non-display side, and the side where the electrophoretic display film is located is the display side. The display method of the electrophoretic display is to input signals of different voltages to the pixel electrodes through the active elements on the active element array substrate, so that the electric field in the electrophoretic display film changes, so that these display particles move. These display particles reflect light from the outside world. Therefore, when the display particles move toward the display side, the color of the particle is displayed, and when the display particles move away from the display side, the color of the display matrix is displayed.

Contents of the invention

The invention provides an electrophoretic display pixel with high display contrast.

The invention provides a display device, which has a plurality of electrophoretic display pixels with high display contrast.

The invention provides an electrophoretic display pixel, which includes an electrophoretic display film, a substrate, a first active element, a second active element, a first electrode and a second electrode. The substrate is arranged on the electrophoretic display film and has a light-transmitting area and a non-light-transmitting area. Both the first active element and the second active element are disposed on the substrate and located in the non-transmissive area. The first electrode is arranged on the substrate, located in the light-transmitting area, and electrically connected to the first active element, and the second electrode is arranged on the substrate, located in the non-light-transmitting area, and electrically connected to the second active element. A light passes through the light-transmitting region and enters the electrophoretic display film for display.

In an embodiment of the present invention, the above-mentioned first active device and the second active device respectively include a gate, a source and a drain. The source and the drain are respectively located on two sides of the gate, and the first electrode is electrically connected to the drain of the first active device, and the second electrode is electrically connected to the drain of the second active device. The material of the gate electrode, the source electrode and the drain electrode is, for example, a non-light-transmitting conductive material. In addition, the electrophoretic display pixel further includes a capacitive electrode disposed on the substrate and located in the non-transmissive area. The material of the capacitor electrode is also, for example, a non-light-transmitting conductive material.

In an embodiment of the present invention, the above-mentioned electrophoretic display pixel further includes two scan lines and a data line, the first active device and the second active device are respectively electrically connected to one of the scan lines, and the first active device and the second The active element is electrically connected to the data line.

In an embodiment of the present invention, the above-mentioned electrophoretic display pixel further includes a scan line and two data lines, the first active device and the second active device are electrically connected to the scan line, and the first active device and the second active device are respectively Electrically connect one of the data lines.

In an embodiment of the present invention, the above-mentioned electrophoretic display film has an electrode layer, a display matrix and a plurality of display particles. The display particles are distributed in the display matrix, and the electrode layer and the active component substrate are located on opposite sides of the display matrix. The display particles are located in the light-transmitting area or in the non-light-transmitting area, for example, controlled by the polarity of the first electrode and the second electrode.

The present invention further proposes a display device, which includes a plurality of above-mentioned electrophoretic display pixels.

In an embodiment of the present invention, the above-mentioned display device includes an electronic paper display and a flexible display panel.

Based on the above, the present invention disposes the active element on the display side, so the electrophoretic display pixel has an opaque element on the display side. When the electrophoretic display pixels display a black picture, the display particles can be located under the opaque element and be covered to improve the display contrast. Therefore, the electrophoretic display pixel and the display device of the present invention have superior display effect, that is, the display contrast is quite good.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail together with the accompanying drawings.

Description of drawings

In order to make the above and other objects, features, advantages and implementation methods of the present invention more clearly understood, the accompanying drawings are described as follows:

FIG. 1 is a schematic top view of an electrophoretic display pixel according to an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of the electrophoretic display pixel shown in FIG. 1 along the section line A-A';

3A-3C are schematic diagrams showing three states of the electrophoretic display pixels shown in FIG. 1 and FIG. 2 ;

FIG. 4 is a schematic top view of some components of an electrophoretic display pixel according to another embodiment of the present invention.

Among them, reference signs

100, 200: Electrophoretic display pixel 110: Electrophoretic display film

112: Electrode layer 114: Display matrix

116: Display particles 118: Light absorbing layer

120: Substrate 122: Translucent area

124: Non-light-transmitting area 130: The first active component

150: the first electrode 140: the second active element

170: capacitance electrode 160: second electrode

190, 292, 294: data lines 182, 184, 280: scanning lines

A-A': Cross-section D: Drain

G: Gate S: Source

I, II, III: State L: Light

Detailed ways

FIG. 1 is a schematic top view of an electrophoretic display pixel according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view of the electrophoretic display pixel of FIG. 1 along the section line A-A'. Please refer to FIG. 1 and FIG. 2 at the same time. The electrophoretic display pixel 100 includes an electrophoretic display film 110 , a substrate 120 , a first active device 130 , a second active device 140 , a first electrode 150 and a second electrode 160 . The substrate 120 is disposed on the electrophoretic display film 110 and has a light-transmitting area 122 and a non-light-transmitting area 124 . Both the first active device 130 and the second active device 140 are disposed on the substrate 120 and located in the non-transmissive area 124 . The first electrode 150 is disposed on the substrate 120, located in the transparent area 122, and electrically connected to the first active device 130, while the second electrode 160 is disposed on the substrate 120, located in the non-transparent area 124, and electrically connected Connect the second active element 140 .

Specifically, the electrophoretic display film 110 has an electrode layer 112 , a display matrix 114 and a plurality of display particles 116 . The display particles 116 are distributed in the display matrix 114 , and the electrode layer 112 and the substrate 120 are located on opposite sides of the display matrix 114 . In this embodiment, the light L passes through the light-transmitting region 122 and enters the electrophoretic display film 110 to be reflected for display, so the side where the substrate 120 is located is the display side.

In other words, when using the electronic device with the electrophoretic display pixel 100 , the user is located on the side where the light L is located, and the user views the image along the incident direction of the light L. Therefore, the material of the first electrode 150 and the second electrode 160 is, for example, a transparent conductive material. In order to improve the display quality, the electrophoretic display pixel 100 further includes, for example, a light absorbing layer 118 disposed on a side of the electrophoretic display film 110 away from the substrate 120 .

3A to 3C are schematic diagrams showing three states of the electrophoretic display pixels shown in FIG. 1 and FIG. 2 , wherein FIG. 3A to FIG. 3C only briefly show the display film, the first electrode and the second electrode. Referring to FIGS. 3A to 3C , the display particles 116 are generally positively or negatively charged particles, so the movement of the display particles 116 can be controlled by the electric fields of the electrode layer 112 , the first electrode 150 and the second electrode 160 .

As shown in FIG. 3A , in state I, assuming that the display particles 116 are positively charged, the electrode layer 112 is applied with a negative voltage, while the first electrode 150 and the second electrode 160 are applied with a positive voltage. Therefore, according to the direction and distribution of the electric field, the display particles 116 will move toward the electrode layer 112 and approach the surface of the electrode layer 112 . At this time, the light L will first pass through the display matrix 114 and then be reflected by the display particles 116 . Therefore, in the state I, the user can see the color of the display matrix 114 on the electrophoretic display pixel 100 when looking along the incident direction of the light L. If the display matrix 114 is red, the electrophoretic display pixel 100 presents a red image in state I. Of course, the color of the display substrate 114 can vary with different designs.

As shown in FIG. 3B , in state II, assuming that the display particles 116 are positively charged, the electrode layer 112 is applied with a positive voltage, while the first electrode 150 and the second electrode 160 are applied with a negative voltage. Therefore, according to the direction and distribution of the electric field, the moving direction of the display particles 116 tends to the surfaces of the first electrode 150 and the second electrode 160 . At this time, the light L is directly reflected by the display particles 116 to display the color of the display particles 116 . If the display particles 116 are white, in the state II, the user can see the electrophoretic display pixel 100 displaying a white image when looking along the incident direction of the light L. Similarly, with the different colors of the display particles 116 , the color of the image displayed by the electrophoretic display pixel 100 in the state II is also different. In other words, in state II, the user will see the color presented by the display particles 116 .

As shown in FIG. 3C , in state III, assuming that the display particles 116 are positively charged, the electrode layer 112 and the first electrode 150 are given a positive voltage, and only the second electrode 160 is given a negative voltage. According to the direction and distribution of the electric field, the positively charged display particles 116 will move to the area where the second electrode 160 is located. That is to say, in addition to the vertical displacement of the display particles 116 in this embodiment, the lateral displacement of the display particles 116 can also be controlled by the change of the electric field of the first electrode 150 and the second electrode 160 .

From FIG. 1, FIG. 2 and FIG. 3A-FIG. 3C, it can be seen that the position of the second electrode 160 is the non-light-transmitting region 124, so in the state III shown in FIG. 118 absorption. Therefore, when the user looks at the electrophoretic display film 110 from one side of the substrate 120 , the light L will not be reflected and the electrophoretic display pixel 100 can see a black picture. It is worth mentioning that the position of the second electrode 160 in this embodiment cannot transmit light, so the light L is not easy to enter the display particles 116 or be reflected out in the state III shown in FIG. 3C . In this way, the electrophoretic display pixel 100 is less likely to generate reflected light when displaying a black image, and can present a darker black image. Through such a design, the electrophoretic display pixel 100 has a relatively high display contrast.

Specifically, please continue to refer to FIG. 1 and FIG. 2 , the electrophoretic display pixel 100 further includes two scan lines 182 , 184 and a data line 190 . The first active device 130 is electrically connected to the scan line 182 , and the second active device 140 is electrically connected to the scan line 184 , and the first active device 130 and the second active device 140 are electrically connected to the same data line 190 . The first active device 130 and the second active device 140 in this embodiment are respectively connected to the scan line 182 and the scan line 184 . Therefore, the first electrode 150 and the second electrode 160 may have different voltages to control the lateral displacement of the display particles 116 .

In this embodiment, the first active device 130 and the second active device 140 include a gate G, a source S and a drain D, respectively. The source S and the drain D are respectively located on both sides of the gate G, and the first electrode 150 is electrically connected to the drain D of the first active device 130 , and the second electrode 160 is electrically connected to the drain of the second active device 140 d. The first active device 130 and the second active device 140 are substantially thin film transistors. The material of the gate G, the source S and the drain D is, for example, a non-light-transmitting conductive material.

In addition, the electrophoretic display pixel 100 further includes a capacitive electrode 170 disposed on the substrate 120 and located in the non-transmissive region 124 . The drain D of the first active device 130 and the drain D of the second active device 140 respectively overlap with the capacitor electrode 170 to form corresponding storage capacitors. The design of the storage capacitor helps to maintain the display stability of the electrophoretic display pixel 100 . In addition, the material of the capacitive electrode 170 is also, for example, a non-light-transmitting conductive material.

The scan lines 182 , 184 , the data lines 190 , the first active element 130 , the second active element 140 and the capacitor electrode 170 are all opaque elements. Therefore, the opaque region 124 in this embodiment can be said to be defined by the positions of these opaque elements. These opaque elements are disposed on the display side (that is, the side where the substrate 120 is located, that is, the side close to the user). Therefore, the electrophoretic display pixel 100 of this embodiment can shield unnecessary light leakage or prevent the light L from being reflected by the display particles 116 in the non-light-transmitting region 124 by these opaque elements, thereby improving the display contrast of the electrophoretic display pixel 100 .

Furthermore, the electrophoretic display pixel 100 of this embodiment can effectively improve the display quality without disposing additional light-shielding elements. Therefore, the electrophoretic display pixel 100 of the present embodiment can be manufactured by using an existing process without complicating the process steps. In addition, the present invention does not limit what kind of elements are located in the non-transparent region 124 , and these elements may include thin film transistors, storage capacitors, etc., which at least include a non-transparent layer to block or reduce the penetration of light.

In detail, the manufacturing method of the electrophoretic display pixel 100 is, for example, to first connect the scanning lines 182, 184, the data lines 190, the first active element 130, the second active element 140, the first electrode 150, the second electrode 160 and the capacitance electrode 170 and other components are manufactured on the substrate 120 by thin film deposition process and photolithography process, etc., which can be applied to the production of active device arrays. Next, the side of the substrate 120 where the above-mentioned elements are disposed is assembled or attached to the electrophoretic display film 110 . In other words, the manufacturing method of the electrophoretic display pixel 100 is substantially the same as that of the conventional electrophoretic display.

Since the components of the electrophoretic display pixel 100 are the same as those of the known electrophoretic display, the design of this embodiment can achieve a high display contrast design without changing the components. Therefore, the design of this embodiment will not complicate the process or increase the cost of the process. Here, the electrophoretic display pixel 100 can be applied, for example, in an electronic paper display or a flexible display.

FIG. 4 is a schematic top view of some components of an electrophoretic display pixel according to another embodiment of the present invention, wherein the electrophoretic display film and the substrate are omitted in FIG. 4 . Referring to FIG. 4 , in another electrophoretic display pixel 200 , the first active device 130 and the second active device 140 are driven by one scan line 280 and two data lines 292 , 294 . The first active device 130 and the second active device 140 are electrically connected to the same scan line 280 . In addition, the first active device 130 is electrically connected to the data line 292 , and the second active device 140 is electrically connected to the data line 294 .

In this embodiment, corresponding signals are transmitted to the first electrode 150 and the second electrode 160 through different data lines 292 and 294 . Therefore, the polarities of the first electrode 150 and the second electrode 160 are determined by independent signals to control the moving direction and position of the display particles (not shown) in the display film (not shown). In addition, both the design of this embodiment and the previous embodiments define the positions of opaque elements such as the first active element 130 , the second active element 140 , and the capacitor electrode 170 as opaque regions. Moreover, the second electrodes 160 are located in the non-transmissive area. Therefore, when displaying a black image, only the display particles (not shown) need to be attracted to the position of the second electrode 160 so as not to reflect light easily. That is to say, the electrophoretic display pixel 200 can display a darker black picture with higher display contrast.

Similarly, the design of this embodiment mainly lies in disposing the opaque element on the display side close to the user. Therefore, when the electrophoretic display pixel 200 of this embodiment displays a black image, the existing opaque elements can be used to shield the display particles (not shown). In this way, the black image displayed by the electrophoretic display pixels 200 is sufficiently black to achieve a display effect of high display contrast.

To sum up, in the present invention, the substrate on which the active components are configured is set as the display side. Therefore, components with opaque properties such as active components and capacitive electrodes can define opaque regions on the substrate. In the present invention, the first electrode and the second electrode are arranged respectively in the light-transmitting area and the non-light-transmitting area to control the lateral movement of the display particles. When the display particles move laterally to the area where the second electrode is located, the display particles will be blocked by the opaque element and cannot reflect light, so a darker black picture can be displayed. Therefore, the electrophoretic display pixel and the display device of the present invention have quite good display contrast. Under such a design, there is no need to greatly change the components and manufacturing method of the electrophoretic display pixel, that is to say, the present invention can achieve a high display contrast display effect under the existing component component design.

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding Changes and deformations should belong to the scope of protection of the appended claims of the present invention.

Claims (12)

1. An electrophoretic display pixel, characterized in that the electrophoretic display pixel comprises: An electrophoretic display film; A substrate, configured on the electrophoretic display film, located on the display side of the electrophoretic display pixel, has a light-transmitting area and a non-light-transmitting area; a first active element, configured on the substrate and located in the non-transmissive area; a second active element, configured on the substrate and located in the non-transmissive area; a first electrode, configured on the substrate, located in the light-transmitting region, and electrically connected to the first active element; and a second electrode, configured on the substrate, located in the non-transparent region, and electrically connected to the second active element; A light penetrates the light-transmitting region and enters the electrophoretic display film for display; wherein, The first active device and the second active device respectively include a gate, a source and a drain, the source and the drain are respectively located on two sides of the gate, and the first electrode is electrically connected to the The drain of the first active device, and the second electrode is electrically connected to the drain of the second active device. 2 . The electrophoretic display pixel according to claim 1 , wherein the material of the gate electrode, the source electrode and the drain electrode is a non-light-transmitting conductive material. 3 . The electrophoretic display pixel according to claim 1 , further comprising a capacitive electrode disposed on the substrate and located in the non-transparent region. 4 . 4 . The electrophoretic display pixel according to claim 3 , wherein the drain of the first active device and the drain of the second active device respectively overlap with the capacitor electrode. 5 . The electrophoretic display pixel according to claim 3 , wherein the capacitor electrode is made of a non-light-transmitting conductive material. 6. The electrophoretic display pixel according to claim 1, wherein the electrophoretic display pixel further comprises two scan lines and a data line, and the first active device and the second active device are respectively electrically connected to one of the scan lines , and the first active device and the second active device are electrically connected to the data line. 7. The electrophoretic display pixel according to claim 1, wherein the electrophoretic display pixel further comprises a scan line and two data lines, the first active device and the second active device are electrically connected to the scan line, and The first active device and the second active device are respectively electrically connected to one of the data lines. 8 . The electrophoretic display pixel according to claim 1 , further comprising a light absorbing layer disposed on a side of the electrophoretic display film away from the substrate. 9. The electrophoretic display pixel according to claim 1, wherein the electrophoretic display film has an electrode layer, a display matrix and a plurality of display particles, the display particles are distributed in the display matrix, and the electrode layer The substrate is located on two opposite sides of the display matrix. 10. The electrophoretic display pixel according to claim 9, wherein the display particles are controlled by the polarity of the first electrode and the second electrode and are located in the light-transmitting region or in the non-light-transmitting region . 11. A display device, characterized in that the display device comprises a plurality of electrophoretic display pixels as claimed in claim 1. 12. The display device according to claim 11, wherein the display device comprises an electronic paper display or a flexible display panel.

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