Circularly polarizing plate and reflective display panel

Abstract

The application discloses a circular polarizer and a reflective display panel, wherein the circular polarizer comprises a linear polarizer and a phase retardation layer, an included angle between a polarization axis of the linear polarizer and a reference axis is in a range of -5° to +5°, and the reference axis is parallel to a straight line corresponding to an edge of the linear polarizer; the phase retardation layer is arranged on a surface of the linear polarizer, and the phase retardation layer comprises odd-numbered quarter-wave plates with different optical axis orientations. The application aims to weaken the influence of the increased transmittance of the circular polarizer on the contrast ratio of the display panel.

Description

Technical Field

[0001] This application relates to the field of display technology, specifically to a circular polarizer and a reflective display panel. Background Technology

[0002] Liquid crystal displays (LCDs) include transmissive LCDs that use a backlight module as a light source and reflective LCDs that use external natural or artificial light as a light source without using a backlight module.

[0003] Although reflective LCD screens have advantages such as eye protection and low power consumption, in order to improve the contrast of reflective LCD screens, they usually have a circular polarizer inside. The circular polarizer includes a linear polarizer and a quarter-wave plate (λ / 4 wave plate). When natural light passes through the linear polarizer from the outside, it forms linearly polarized light. Due to the design of the linear polarizer, the transmittance of the circular polarizer is low, resulting in a low reflectance of the reflective LCD screen. However, if only the transmittance of the circular polarizer is increased, it will lead to a decrease in the contrast of the reflective LCD screen.

[0004] Therefore, it is necessary to propose a new technical solution to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this application is to provide a circular polarizer and a reflective display panel, which aims to reduce the impact of increased light transmittance of the circular polarizer on the contrast of the display panel.

[0006] To solve the above problems, the technical solution of this application is as follows:

[0007] In a first aspect, this application proposes a circular polarizer, comprising:

[0008] A linear polarizer, wherein the angle between the polarization axis of the linear polarizer and the reference axis is within the range of -5° to +5°, and the reference axis is parallel to a straight line corresponding to one edge of the linear polarizer; and

[0009] A phase retardation layer is disposed on one surface of the linear polarizer, and the phase retardation layer includes an odd number of quarter-wave plates with different optical axis orientations.

[0010] In one embodiment of the present invention, the number of quarter-wave plates is greater than or equal to three, and an odd number of quarter-wave plates are stacked sequentially on one surface of the linear polarizer, and the angle between the optical axis of the quarter-wave plate and the reference axis is in the range of -60° to +60°.

[0011] In one embodiment of the present invention, the angle between the optical axis of two adjacent quarter-wave plates and the reference axis gradually increases along a direction perpendicular to the plane corresponding to the linear polarizer and away from the linear polarizer, and the angle between the optical axis of the quarter-wave plate and the reference axis is in the range of +35° to +55°.

[0012] In one embodiment of the present invention, the phase delay layer includes:

[0013] A first quarter-wave plate is disposed on one surface of the linear polarizer, and the angle between the optical axis of the first quarter-wave plate and the reference axis in the clockwise direction is within the range of +35° to +45°.

[0014] A second quarter-wave plate is disposed on a surface of the first quarter-wave plate opposite to the linear polarizer, and the optical axis of the second quarter-wave plate forms an angle of +40° to +50° with the reference axis in a clockwise direction; and

[0015] The third quarter-wave plate is disposed on a surface of the second quarter-wave plate opposite to the linear polarizer, and the optical axis of the third quarter-wave plate forms an angle between the optical axis and the reference axis in a clockwise direction within the range of +45° to +55°.

[0016] Wherein, the angle between the optical axis of the first quarter-wave plate and the reference axis in the clockwise direction is smaller than the angle between the optical axis of the second quarter-wave plate and the reference axis in the clockwise direction, and the angle between the optical axis of the second quarter-wave plate and the reference axis in the clockwise direction is smaller than the angle between the optical axis of the third quarter-wave plate and the reference axis in the clockwise direction.

[0017] In one embodiment of the present invention, the angle between the optical axis of two adjacent quarter-wave plates and the reference axis gradually decreases along a direction perpendicular to the plane corresponding to the linear polarizer and away from the linear polarizer, and the angle between the optical axis of the quarter-wave plate and the reference axis is in the range of -35° to -55°.

[0018] In one embodiment of the present invention, the phase delay layer includes:

[0019] A first quarter-wave plate is disposed on one surface of the linear polarizer, and the angle between the optical axis of the first quarter-wave plate and the reference axis in the counterclockwise direction is in the range of -45° to -55°.

[0020] A second quarter-wave plate is disposed on a surface of the first quarter-wave plate opposite to the linear polarizer, and the angle between the optical axis of the second quarter-wave plate and the reference axis in a counterclockwise direction is within the range of -40° to -50°; and

[0021] The third quarter-wave plate is disposed on a surface of the second quarter-wave plate opposite to the linear polarizer, and the angle between the optical axis of the third quarter-wave plate and the reference axis in the counterclockwise direction is in the range of -35° to -45°.

[0022] Wherein, the angle between the optical axis of the first quarter-wave plate and the reference axis in the counterclockwise direction is greater than the angle between the optical axis of the second quarter-wave plate and the reference axis in the counterclockwise direction, and the angle between the optical axis of the second quarter-wave plate and the reference axis in the counterclockwise direction is greater than the angle between the optical axis of the third quarter-wave plate and the reference axis in the counterclockwise direction.

[0023] In one embodiment of the present invention, the phase delay sheet layer further includes a half-wave plate, which is stacked between the odd-numbered quarter-wave plates and the linear polarizer.

[0024] In one embodiment of the present invention, the phase delay sheet layer further includes a half-wave plate, and the odd-numbered quarter-wave plates and the half-wave plates are sequentially stacked on one surface of the linear polarizer.

[0025] In one embodiment of the present invention, the linear polarizer includes:

[0026] Polarizing functional layer; and

[0027] Multiple dichroic dye molecules are disposed in the polarizing functional layer, and the angle between the stretching direction of the dichroic dye molecules and the reference axis is in the range of -5° to +5°.

[0028] Secondly, this application proposes a reflective display panel, comprising:

[0029] Array substrate;

[0030] A reflective layer is disposed on the array substrate;

[0031] A liquid crystal layer, wherein the liquid crystal layer is disposed on the reflective layer;

[0032] Opposing substrate, the opposing substrate being disposed on the liquid crystal layer; and

[0033] A circular polarizer includes a linear polarizer and a phase retardation layer. The angle between the polarization axis of the linear polarizer and a reference axis is in the range of -5° to +5°. The reference axis is parallel to a straight line corresponding to one edge of the linear polarizer. The phase retardation layer is disposed on one surface of the linear polarizer and includes an odd number of quarter-wave plates with different optical axis orientations.

[0034] The circular polarizer is disposed on the opposing substrate, and the phase delay film layer is located between the opposing substrate and the linear polarizer.

[0035] In this application, by reducing the polarization degree of the linear polarizer, the linear polarizer can transmit polarized light with the polarization direction at an angle between -5° and +5° to the reference axis. Compared to linear polarizers with higher polarization degree that can only transmit polarized light with a single polarization direction, the design of the linear polarizer with lower polarization degree in this solution improves the transmittance of the circular polarizer, thereby improving the reflectivity of the reflective liquid crystal display. At the same time, the phase retardation layer includes a quarter-wave plate with an odd number of layers of optical axis orientations that are different. The quarter-wave plate is used to delay the phase of the polarized light transmitted through the linear polarizer, so that some of the polarized light that enters the display panel without being deflected by the liquid crystal layer cannot exit the reflective display panel from the linear polarizer, thereby improving the contrast of the reflective display panel and reducing the impact of the increased transmittance of the circular polarizer on the contrast of the display panel. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of an embodiment of the circular polarizer of this application;

[0037] Figure 2 This is a schematic diagram of another embodiment of the circular polarizer of this application;

[0038] Figure 3 This is a schematic diagram of yet another embodiment of the circular polarizer of this application;

[0039] Figure 4 This is a schematic diagram of yet another embodiment of the circular polarizer of this application;

[0040] Figure 5 These are schematic diagrams of other embodiments of the circular polarizer of this application;

[0041] Figure 6 These are schematic diagrams of other embodiments of the circular polarizer of this application;

[0042] Figure 7 This is a schematic diagram of an embodiment of the linear polarizer of this application;

[0043] Figure 8 This is a schematic diagram of another embodiment of the linear polarizer of this application. Detailed Implementation

[0044] Unless otherwise defined, the terms used in this specification and claims have the meanings commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used in this specification and claims is for the purpose of facilitating the description and understanding of this application only, and is not intended to limit this application to the narrow interpretation of the specific terms used in the specification and claims.

[0045] Reference Figures 1 to 8 In a first aspect, this application proposes a reflective display panel, comprising:

[0046] Array substrate;

[0047] A reflective layer is disposed on the array substrate;

[0048] A liquid crystal layer, wherein the liquid crystal layer is disposed on the reflective layer;

[0049] Opposing substrate, the opposing substrate being disposed on the liquid crystal layer; and

[0050] A circular polarizer 100 includes a linear polarizer 10 and a phase retardation layer 20. The polarization axis 11 of the linear polarizer 10 forms an angle between a reference axis 12 and a polarization axis 12 within the range of -5° to +5°. The reference axis 12 is parallel to a straight line corresponding to one edge of the linear polarizer 10. The phase retardation layer 20 is disposed on one surface of the linear polarizer 10 and includes a quarter-wave plate 21 with an odd number of layers of optical axes 30 having different orientations.

[0051] The circular polarizer 100 is disposed on the opposing substrate, and the phase delay layer 20 is located between the opposing substrate and the linear polarizer 10.

[0052] The color filter layer can be disposed on the opposing substrate or on the array substrate.

[0053] When the liquid crystal molecules in the liquid crystal layer do not deflect, incident natural light passes through the linear polarizer 10, the quarter-wave plates 21 (with different orientations on the odd-numbered optical axes 30), and the liquid crystal layer, becoming circularly polarized and elliptically polarized light. This incident light is then reflected by the reflective layer and passes again through the liquid crystal layer and the quarter-wave plates 21 (with different orientations on the odd-numbered optical axes 30), becoming linearly polarized and elliptically polarized light. The polarization direction of the linearly polarized light is perpendicular to the polarization axis 11 of the linear polarizer 10, preventing it from exiting the reflective display panel and improving its contrast. The elliptically polarized light can be decomposed into two beams of linearly polarized light with mutually perpendicular polarization directions and a fixed phase difference. In the reflective display panel, the portion of elliptically polarized light parallel to the polarization axis 11 of the linear polarizer 10 passes through the linear polarizer 10 and exits. The portion of elliptically polarized light perpendicular to the polarization axis 11 of the linear polarizer 10 cannot exit the reflective display panel, thereby improving the contrast of the reflective display panel. To further improve the contrast of the reflective display panel, it is necessary to increase the proportion of linearly polarized light in the incident light before exiting the linear polarizer 10. Specifically, after natural light passes through the linear polarizer 10, when the polarization direction of the linearly polarized light makes an angle of 45° with the optical axis 30 of the quarter-wave plate 21, the polarized light with this polarization direction can form linearly polarized light when exiting the reflective display panel from the linear polarizer 10. Therefore, by using quarter-wave plates 21 with different orientations in odd-numbered layers, linearly polarized light with multiple polarization directions at an angle of 45° to the optical axis 30 of multiple quarter-wave plates 21 can be transformed into circularly polarized light and then back into linearly polarized light, which cannot pass through the reflective display panel from the linear polarizer 10, thereby improving the contrast of the reflective display panel.

[0054] When the liquid crystal molecules in the liquid crystal layer are deflected, the incident natural light passes through the linear polarizer 10, the quarter-wave plate 21 with different orientations of the odd-numbered optical axes 30, and the liquid crystal layer, becoming linearly polarized light and elliptically polarized light. Then, the incident light is reflected by the reflective layer and passes through the liquid crystal layer and the quarter-wave plate 21 with different orientations of the odd-numbered optical axes 30 again, becoming linearly polarized light and elliptically polarized light. The polarization direction of the linearly polarized light is parallel to the polarization axis 11 of the linear polarizer 10, so that the linearly polarized light can exit the reflective display panel from the linear polarizer 10. The elliptically polarized light can be decomposed into two beams of linearly polarized light with mutually perpendicular polarization directions and a fixed phase difference. The part of the elliptically polarized light parallel to the polarization axis 11 of the linear polarizer 10 passes through the linear polarizer 10 and exits the reflective display panel, while the part of the elliptically polarized light perpendicular to the polarization axis 11 of the linear polarizer 10 cannot exit the reflective display panel from the linear polarizer 10.

[0055] A half-wave plate 22 is provided between the online polarizer 10 and the odd-numbered quarter-wave plate 21 to provide wide wavelength compensation, thereby improving the contrast of the reflective display panel; or, a half-wave plate 22 is provided on one surface of the odd-numbered quarter-wave plate 21 behind the online polarizer 10 to provide wide wavelength compensation, thereby improving the contrast of the reflective display panel.

[0056] The angle between the optical axis 40 of the half-wave plate 22 and the reference axis 12 is set according to the deflection angle of the liquid crystal layer and the optical axis 30 of the quarter-wave plate 21.

[0057] When polarized light passes through the color filter layer, it can form polarized light with corresponding colors, including red, green and blue.

[0058] In the absence of a backlight structure and external artificial light as a light source, the circular polarizer 100 in this solution can increase the reflectivity of the display panel by increasing the transmittance, and reduce the impact of the increased transmittance of the circular polarizer on the contrast of the display panel.

[0059] The liquid crystal layer comprises multiple liquid crystal molecules, which are λ / 4 plates. When the liquid crystal molecules are not deflected, the major axis of the λ / 4 plate is parallel to the light emission direction. In this case, circularly polarized or elliptically polarized light passing through the odd-numbered quarter-wave plate 21 will not change its polarization state when passing through the liquid crystal layer. When the liquid crystal molecules are deflected, the major axis of the λ / 4 plate is perpendicular to the light emission direction. In this case, circularly polarized or elliptically polarized light passing through the odd-numbered quarter-wave plate 21 will become linearly polarized or elliptically polarized light when passing through the liquid crystal layer.

[0060] Reference Figures 1 to 8 Secondly, this application proposes a circular polarizer 100, comprising:

[0061] A linear polarizer 10, wherein the angle between the polarization axis 11 and the reference axis 12 of the linear polarizer 10 is within the range of -5° to +5°, and the reference axis 12 is parallel to the straight line corresponding to one edge of the linear polarizer 10; and

[0062] A phase retardation layer 20 is disposed on one surface of the linear polarizer 10. The phase retardation layer 20 includes a number of quarter-wave plates 21 with different orientations of their odd-numbered optical axes 30.

[0063] In this application, by reducing the polarization degree of the linear polarizer 10, the linear polarizer 10 can transmit polarized light whose polarization direction is within the range of -5° to +5° with respect to the reference axis 12. Compared with a linear polarizer 10 with a higher polarization degree that can only transmit polarized light with a single polarization direction, the design of the linear polarizer 10 with a lower polarization degree in this solution improves the transmittance of the circular polarizer 100, thereby improving the reflectivity of the reflective liquid crystal display. At the same time, the phase retardation layer 20 includes quarter-wave plates 21 with different orientations of the odd-numbered optical axes 30. The quarter-wave plates 21 are used to delay the phase of the polarized light transmitted through the linear polarizer 10, so that some of the polarized light that enters the display panel without being deflected by the liquid crystal layer cannot exit the reflective display panel from the linear polarizer 10, thereby improving the contrast of the reflective display panel and reducing the impact of the increased transmittance of the circular polarizer 100 on the contrast of the display panel.

[0064] The linear polarizer 10 is typically rectangular in shape, and the reference axis 12 is parallel to the straight line corresponding to one edge of the rectangular linear polarizer 10.

[0065] By setting quarter-wave plates 21 with different orientations for the odd-numbered optical axes 30, the contrast of the reflective display panel can be improved. Because the angle between the polarization axis 11 and the reference axis 12 of the linear polarizer 10 in this scheme is in the range of -5° to +5°, linearly polarized light with a polarization direction in the range of -5° to +5° can pass through the linear polarizer 10 and enter the interior of the reflective display panel. The transmittance of the circular polarizer 100 is increased, resulting in a decrease in the contrast of the reflective display panel. To improve the contrast of the display panel, a quarter-wave plate 21 can be configured with an angle of approximately 45° between the optical axis 30 and the polarization direction of the linearly polarized light. When the polarization direction of the linearly polarized light passing through the quarter-wave plate 21 is at a 45° angle to the optical axis 30 of the quarter-wave plate 21, the linearly polarized light becomes circularly polarized light. When the circularly polarized light exits the reflective display panel from the linear polarizer 10, it becomes linearly polarized light with a polarization direction perpendicular to the polarization axis 11 of the linear polarizer 10, and thus cannot exit the reflective display panel, thereby improving the contrast of the reflective display panel. However, when the polarization direction of the linearly polarized light passing through the quarter-wave plate 21 is not at a 45° angle to the optical axis 30 of the quarter-wave plate 21, the linearly polarized light... The light becomes elliptically polarized. When the elliptically polarized light exits the reflective display panel from the linear polarizer 10, the portion of the elliptically polarized light perpendicular to the polarization axis 11 of the linear polarizer 10 cannot exit the reflective display panel, but the portion of the elliptically polarized light parallel to the polarization axis 11 of the linear polarizer 10 can exit the reflective display panel, resulting in a decrease in the contrast of the reflective display panel. By setting quarter-wave plates 21 with different orientations for the odd-numbered optical axes 30, the optical axes 30 of the odd-numbered quarter-wave plates 21 can form a 45° angle with the polarization direction of the linearly polarized light from the multi-channel incident linear polarizer 10, thereby increasing the proportion of the circular polarizer 100 after passing through the quarter-wave plates 21, and thus correspondingly improving the contrast of the reflective display panel.

[0066] Reference Figures 3 to 6 In one embodiment of the present invention, the number of quarter-wave plates 21 is greater than or equal to three, and an odd number of quarter-wave plates 21 are stacked sequentially on one surface of the linear polarizer 10. The angle between the optical axis 30 of the quarter-wave plate 21 and the reference axis 12 is in the range of -60° to +60°.

[0067] In one embodiment of the present invention, the phase delay layer 20 has three or more quarter-wave plates 21. The number of quarter-wave plates 21 can be any one of the following values: 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, or 29. The angle between any quarter-wave plate 21 and the reference axis 12 can be -54°, ​​-53°, -52°, -51°, -50°, -49°, or -48°. A value from -47°, -46°, -45°, -44°, -43°, -42°, -41°, -40°, -39°, -38°, -37°, -36°, +36°, +37°, +38°, +39°, +40°, +41°, +42°, +43°, +44°, +45°, +46°, +47°, +48°, +49°, +50°, +51°, +52°, +53°, +54°.

[0068] In the odd-numbered quarter-wave plates 21, the angle between the optical axis 30 of any two adjacent quarter-wave plates 21 and the reference axis 12 can be random, or it can increase or decrease along the direction perpendicular to the plane corresponding to the linear polarizer 10 and away from the linear polarizer 10.

[0069] Reference Figure 3 and Figure 4 In one embodiment of the present invention, the angle between the optical axis 30 of two adjacent quarter-wave plates 21 and the reference axis 12 gradually increases along a direction perpendicular to the plane corresponding to the linear polarizer 10 and away from the linear polarizer 10, and the angle between the optical axis 30 of the quarter-wave plate 21 and the reference axis 12 is in the range of +35° to +55°.

[0070] In one embodiment of the present invention, when the number of quarter-wave plates 21 in the phase delay layer 20 is five, the phase delay layer 20 includes:

[0071] A first quarter-wave plate 211 is disposed on one surface of the linear polarizer 10. The angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the clockwise direction is in the range of +37° to +40°. The angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the clockwise direction is one of +37°, +37.5°, +38°, +38.5°, +39°, +39.5°, and +40°.

[0072] The second quarter-wave plate 212 is disposed on a surface of the first quarter-wave plate 211 opposite to the linear polarizer 10. The optical axis 30 of the second quarter-wave plate 212 forms an angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the clockwise direction within the range of +40° to +43°. The angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the clockwise direction is one of the following values: +40°, +40.5°, +41°, +41.5°, +42°, +42.5°, and +43°.

[0073] The third quarter-wave plate 213 is disposed on a surface of the second quarter-wave plate 212 opposite to the linear polarizer 10. The optical axis 30 of the third quarter-wave plate 213 forms an angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the clockwise direction within the range of +43° to +46°. The angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the clockwise direction is one of the following values: +43°, +43.5°, +44°, +44.5°, +45°, +45.5°, and +46°.

[0074] A fourth quarter-wave plate is disposed on a surface of the third quarter-wave plate 213 opposite to the linear polarizer 10. The optical axis 30 of the fourth quarter-wave plate forms an angle between the optical axis 30 of the fourth quarter-wave plate and the reference axis 12 in a clockwise direction within the range of +46° to +49°. The angle between the optical axis 30 of the fourth quarter-wave plate and the reference axis 12 in a clockwise direction is one of the following values: +46°, +46.5°, +47°, +47.5°, +48°, +48.5°, and +49°.

[0075] A fifth quarter-wave plate is disposed on a surface of the fourth quarter-wave plate opposite to the linear polarizer 10. The optical axis 30 of the fifth quarter-wave plate forms an angle between the optical axis 30 of the fifth quarter-wave plate and the reference axis 12 in a clockwise direction within the range of +49° to +53°. The angle between the optical axis 30 of the fifth quarter-wave plate and the reference axis 12 in a clockwise direction is one of the following values: +49°, +49.5°, +50°, +50.5°, +51°, +51.5°, +52°, +52.5°, and +53°.

[0076] Wherein, the angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the clockwise direction is smaller than the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the clockwise direction; the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the clockwise direction is smaller than the angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the clockwise direction; the angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the clockwise direction is smaller than the angle between the optical axis 30 of the fourth quarter-wave plate and the reference axis 12 in the clockwise direction; and the angle between the optical axis 30 of the fourth quarter-wave plate and the reference axis 12 in the clockwise direction is smaller than the angle between the optical axis 30 of the fifth quarter-wave plate and the reference axis 12 in the clockwise direction.

[0077] The closer the angle between the polarization direction of the linearly polarized light passing through the linear polarizer 10 and the optical axis 30 of the quarter-wave plate 21 is to 45°, the closer the partially polarized light formed after passing through the quarter-wave plate 21 is to circularly polarized light. The higher the proportion of circularly polarized light, the higher the contrast of the reflective display panel. When the angle between the polarization direction of the linearly polarized light passing through the linear polarizer 10 and the reference axis 12 is within the range of -5° to +5°,

[0078] By setting an odd-numbered quarter-wave plate 21 that gradually increases in size along a direction perpendicular to the plane corresponding to the linear polarizer 10 and away from the linear polarizer 10, and the angle between the odd-numbered quarter-wave plate 21 and the reference axis 12 is in the range of +35° to +55°, the linearly polarized light that has passed through the linear polarizer 10 can all pass through the quarter-wave plate 21, whose direction of the optical axis 30 is at an angle of approximately 45° to the polarization direction of the linearly polarized light, thereby increasing the proportion of circularly polarized light and thus improving the contrast of the reflective display panel.

[0079] Reference Figure 4 In another technical solution of an embodiment of the present invention, the phase delay layer 20 includes:

[0080] A first quarter-wave plate 211 is disposed on one surface of the linear polarizer 10. The angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the counterclockwise direction is within the range of -35° to -45°. The angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the counterclockwise direction is one of the following values: -35°, -35.5°, -36°, -36.5°, -37°, -37.5°, -38°, -38.5°, -39°, -39.5°, -40°, -40.5°, -41°, -41.5°, -42°, -42.5°, -43°, -43.5°, -44°, -44.5°, and -45°.

[0081] A second quarter-wave plate 212 is disposed on a surface of the first quarter-wave plate 211 facing away from the linear polarizer 10. The optical axis 30 of the second quarter-wave plate 212 forms an angle between the optical axis 30 and the reference axis 12 in a counterclockwise direction within the range of -40° to -50°. The angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in a counterclockwise direction is one of the following values: -40°, -40.5°, -41°, -41.5°, -42°, -42.5°, -43°, -43.5°, -44°, -44.5°, -45°, -45.5°, -46°, -46.5°, -47°, -47.5°, -48°, -48.5°, -49°, -49.5°, and -50°.

[0082] A third quarter-wave plate 213 is disposed on a surface of the second quarter-wave plate 212 facing away from the linear polarizer 10. The optical axis 30 of the third quarter-wave plate 213 forms an angle between the optical axis 30 and the reference axis 12 in a counterclockwise direction within the range of -45° to -55°. The angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in a counterclockwise direction is one of the following values: -45°, -45.5°, -46°, -46.5°, -47°, -47.5°, -48°, -48.5°, -49°, -49.5°, -50°, -50.5°, -51°, -51.5°, -52°, -52.5°, -53°, -53.5°, -54°, ​​-54.5°, and -55°.

[0083] Wherein, the angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the counterclockwise direction is smaller than the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the counterclockwise direction, and the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the counterclockwise direction is smaller than the angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the counterclockwise direction.

[0084] Reference Figure 3 In one embodiment of the present invention, the phase delay layer 20 includes:

[0085] A first quarter-wave plate 211 is disposed on one surface of the linear polarizer 10, and the optical axis 30 of the first quarter-wave plate 211 forms an angle between the optical axis 30 and the reference axis 12 in the clockwise direction within the range of +35° to +45°.

[0086] A second quarter-wave plate 212 is disposed on a surface of the first quarter-wave plate 211 opposite to the linear polarizer 10. The optical axis 30 of the second quarter-wave plate 212 forms an angle of +40° to +50° with the reference axis 12 in a clockwise direction.

[0087] The third quarter-wave plate 213 is disposed on a surface of the second quarter-wave plate 212 away from the linear polarizer 10, and the optical axis 30 of the third quarter-wave plate 213 forms an angle of +45° to +55° with the reference axis 12 in a clockwise direction.

[0088] Wherein, the angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the clockwise direction is smaller than the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the clockwise direction, and the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the clockwise direction is smaller than the angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the clockwise direction.

[0089] In one embodiment of the present invention, the angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the clockwise direction is one of the following values: +35°, +35.5°, +36°, +36.5°, +37°, +37.5°, +38°, +38.5°, +39°, +39.5°, +40°, +40.5°, +41°, +41.5°, +42°, +42.5°, +43°, +43.5°, +44°, +44.5°, and +45°; the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the clockwise direction is one of the following values: +40°, +40.5°, +41°, +41.5°, +42°, +42.5°, and +43°. The angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the clockwise direction is one of the following values: +43.5°, +44°, +44.5°, +45°, +45.5°, +46°, +46.5°, +47°, +47.5°, +48°, +48.5°, +49°, +49.5°, +50°, +50.5°, +51°, +51.5°, +52°, +52.5°, +53°, +53.5°, +54°, +54.5°, +55°.

[0090] Reference Figure 5 and Figure 6 In one embodiment of the present invention, the angle between the optical axis 30 of two adjacent quarter-wave plates 21 and the reference axis 12 gradually decreases along a direction perpendicular to the plane corresponding to the linear polarizer 10 and away from the linear polarizer 10, and the angle between the optical axis 30 of the quarter-wave plate 21 and the reference axis 12 is in the range of -35° to -55°.

[0091] In one embodiment of the present invention, when the number of quarter-wave plates 21 in the phase delay layer 20 is five, the phase delay layer 20 includes:

[0092] A first quarter-wave plate 211 is disposed on one surface of the linear polarizer 10. The angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the counterclockwise direction is in the range of -49° to -53°. The angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the counterclockwise direction is one of the following values: -49°, -49.5°, -50°, -50.5°, -51°, -51.5°, -52°, -52.5°, and -53°.

[0093] The second quarter-wave plate 212 is disposed on a surface of the first quarter-wave plate 211 away from the linear polarizer 10. The optical axis 30 of the second quarter-wave plate 212 forms an angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the counterclockwise direction, which is in the range of -46° to -49°. The value of the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the counterclockwise direction is one of the following values: -46°, -46.5°, -47°, -47.5°, -48°, -48.5°, and -49°.

[0094] The third quarter-wave plate 213 is disposed on a surface of the second quarter-wave plate 212 away from the linear polarizer 10. The optical axis 30 of the third quarter-wave plate 213 forms an angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the counterclockwise direction, which is in the range of -43° to -46°. The angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the counterclockwise direction is one of the following values: -43°, -43.5°, -44°, -44.5°, -45°, -45.5°, and -46°.

[0095] A fourth quarter-wave plate is disposed on a surface of the third quarter-wave plate 213 opposite to the linear polarizer 10. The optical axis 30 of the fourth quarter-wave plate forms an angle between the optical axis 30 of the fourth quarter-wave plate and the reference axis 12 in a counterclockwise direction within the range of -40° to -43°. The angle between the optical axis 30 of the fourth quarter-wave plate and the reference axis 12 in a counterclockwise direction is one of the following values: -40°, -40.5°, -41°, -41.5°, -42°, -42.5°, and -43°.

[0096] A fifth quarter-wave plate is disposed on a surface of the fourth quarter-wave plate opposite to the linear polarizer 10. The optical axis 30 of the fifth quarter-wave plate forms an angle between the optical axis 30 and the reference axis 12 in a counterclockwise direction within the range of -37° to -40°. The angle between the optical axis 30 of the fifth quarter-wave plate and the reference axis 12 in a counterclockwise direction is one of the following values: -37°, -37.5°, -38°, -38.5°, -39°, -39.5°, and -40°.

[0097] Wherein, the angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the counterclockwise direction is greater than the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the counterclockwise direction; the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the counterclockwise direction is greater than the angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the counterclockwise direction; the angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the counterclockwise direction is greater than the angle between the optical axis 30 of the fourth quarter-wave plate and the reference axis 12 in the counterclockwise direction; and the angle between the optical axis 30 of the fourth quarter-wave plate and the reference axis 12 in the counterclockwise direction is greater than the angle between the optical axis 30 of the fifth quarter-wave plate and the reference axis 12 in the counterclockwise direction.

[0098] The closer the angle between the polarization direction of the linearly polarized light passing through the linear polarizer 10 and the optical axis 30 of the quarter-wave plate 21 is to 45°, the closer the partially polarized light formed after passing through the quarter-wave plate 21 is to circularly polarized light. The higher the proportion of circularly polarized light, the higher the contrast of the reflective display panel. The angle between the polarization direction of the linearly polarized light passing through the linear polarizer 10 and the reference axis 12 is in the range of -5° to +5°. By setting an odd number of quarter-wave plates 21 that gradually decrease in size along a direction perpendicular to the plane corresponding to the linear polarizer 10 and away from the linear polarizer 10, and the angle between the odd number of quarter-wave plates 21 and the reference axis 12 is in the range of -35° to -55°, all the linearly polarized light passing through the linear polarizer 10 can pass through the quarter-wave plate 21, where the angle between the optical axis 30 and the polarization direction of the linearly polarized light is close to 45°. This increases the proportion of circularly polarized light, thereby improving the contrast of the reflective display panel.

[0099] Reference Figure 6 In another technical solution of an embodiment of the present invention, the phase delay layer 20 includes:

[0100] A first quarter-wave plate 211 is disposed on one surface of the linear polarizer 10. The angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the clockwise direction is within the range of +45° to +55°. The angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the clockwise direction is one of the following values: +45°, +45.5°, +46°, +46.5°, +47°, +47.5°, +48°, +48.5°, +49°, +49.5°, +50°, +50.5°, +51°, +51.5°, +52°, +52.5°, +53°, +53.5°, +54°, +54.5°, and +55°.

[0101] A second quarter-wave plate 212 is disposed on a surface of the first quarter-wave plate 211 opposite to the linear polarizer 10. The optical axis 30 of the second quarter-wave plate 212 forms an angle between the optical axis 30 and the reference axis 12 in a clockwise direction within the range of +40° to +50°. The angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in a clockwise direction is one of the following values: +40°, +40.5°, +41°, +41.5°, +42°, +42.5°, +43°, +43.5°, +44°, +44.5°, +45°, +45.5°, +46°, +46.5°, +47°, +47.5°, +48°, +48.5°, +49°, +49.5°, and +50°.

[0102] A third quarter-wave plate 213 is disposed on a surface of the second quarter-wave plate 212 opposite to the linear polarizer 10. The optical axis 30 of the third quarter-wave plate 213 forms an angle between the optical axis 30 and the reference axis 12 in a clockwise direction within the range of +35° to +45°. The angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in a clockwise direction is one of the following values: +35°, +35.5°, +36°, +36.5°, +37°, +37.5°, +38°, +38.5°, +39°, +39.5°, +40°, +40.5°, +41°, +41.5°, +42°, +42.5°, +43°, +43.5°, +44°, +44.5°, and +45°.

[0103] Wherein, the angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the clockwise direction is greater than the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the clockwise direction, and the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the clockwise direction is greater than the angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the clockwise direction.

[0104] Reference Figure 5 In one embodiment of the present invention, the phase delay layer 20 includes:

[0105] A first quarter-wave plate 211 is disposed on one surface of the linear polarizer 10, and the optical axis 30 of the first quarter-wave plate 211 forms an angle between the optical axis 30 and the reference axis 12 in the counterclockwise direction within the range of -45° to -55°.

[0106] The second quarter-wave plate 212 is disposed on a surface of the first quarter-wave plate 211 that is away from the linear polarizer 10. The optical axis 30 of the second quarter-wave plate 212 is at an angle of -40° to -50° with the reference axis 12 in the counterclockwise direction.

[0107] The third quarter-wave plate 213 is disposed on a surface of the second quarter-wave plate 212 away from the linear polarizer 10, and the optical axis 30 of the third quarter-wave plate 213 forms an angle between the optical axis 30 and the reference axis 12 in the counterclockwise direction within the range of -35° to -45°.

[0108] Wherein, the angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the counterclockwise direction is greater than the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the counterclockwise direction, and the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the counterclockwise direction is greater than the angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the counterclockwise direction.

[0109] In one embodiment of the present invention, the angle between the optical axis 30 of the first quarter-wave plate 211 and the reference axis 12 in the counterclockwise direction is one of the following values: -45°, -45.5°, -46°, -46.5°, -47°, -47.5°, -48°, -48.5°, -49°, -49.5°, -50°, -50.5°, -51°, -51.5°, -52°, -52.5°, -53°, -53.5°, -54°, ​​-54.5°, and -55°; the angle between the optical axis 30 of the second quarter-wave plate 212 and the reference axis 12 in the counterclockwise direction is one of the following values: -40°, -40.5°, -41°, -41.5°, -42°, -42.5°, and -43°. The angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the counterclockwise direction is one of the following values: -43.5°, -44°, -44.5°, -45°, -45.5°, -46°, -46.5°, -47°, -47.5°, -48°, -48.5°, -49°, -49.5°, -50°; and the angle between the optical axis 30 of the third quarter-wave plate 213 and the reference axis 12 in the counterclockwise direction is one of the following values: -35°, -35.5°, -36°, -36.5°, -37°, -37.5°, -38°, -38.5°, -39°, -39.5°, -40°, -40.5°, -41°, -41.5°, -42°, -42.5°, -43°, -43.5°, -44°, -44.5°, -45°.

[0110] Reference Figure 1 In one embodiment of the present invention, the phase delay layer 20 further includes a half-wave plate 22, which is stacked between the odd-numbered quarter-wave plates 21 and the linear polarizer 10.

[0111] In one embodiment of the present invention, no quarter-wave plate 21 can produce a quarter-wavelength phase difference for all wavelengths of light. That is, the phase difference level varies with the wavelength of the light; generally, the longer the wavelength, the smaller the phase difference level. Therefore, elliptically polarized light, rather than circularly polarized light, is generated in a wavelength range outside the predetermined wavelength bandwidth.

[0112] Elliptically polarized light makes it more difficult to control the propagation of polarization-based light. In order to provide a phase difference of a quarter wavelength for light with a wide wavelength bandwidth, an achromatic film must be provided.

[0113] Therefore, for light with a wide wavelength bandwidth, a quarter-wavelength phase difference can be obtained by setting a half-wave plate 22 between the odd-numbered quarter-wave plate 21 and the linear polarizer 10. The half-wave plate 22 plays a role in wide wavelength compensation, thereby improving the contrast of the reflective display panel.

[0114] The number of half-wave plates 22 can be one or more. When there are multiple half-wave plates 22, the number of half-wave plates 22 can be one of the following values: 2, 3, 4, 5, 6, 7, 8, 9, or 10. The angle between the optical axis 40 of different half-wave plates 22 and the reference axis 12 can be the same or different.

[0115] The angle between the optical axis 40 of the half-wave plate 22 and the reference axis 12 depends on multiple factors, such as the deflection angle of the liquid crystal molecules in the liquid crystal layer, the number of quarter-wave plates 21, and the optical axis 30 angle of the quarter-wave plate 21.

[0116] Reference Figure 2 In one embodiment of the present invention, the phase delay layer 20 further includes a half-wave plate 22, and the odd-numbered quarter-wave plates 21 and the half-wave plates 22 are sequentially stacked on one surface of the linear polarizer 10.

[0117] In one embodiment of the present invention, the half-wave plate 22 can also be disposed on one surface of the offline polarizer 10 behind the odd-numbered quarter-wave plate 21, so as to play the role of wide wavelength compensation, thereby improving the contrast of the reflective display panel.

[0118] The number of half-wave plates 22 can be one or more. When there are multiple half-wave plates 22, the number of half-wave plates 22 can be one of the following values: 2, 3, 4, 5, 6, 7, 8, 9, or 10. The angle between the optical axis 40 of different half-wave plates 22 and the reference axis 12 can be the same or different.

[0119] Reference Figure 8 In one embodiment of the present invention, the linear polarizer 10 includes:

[0120] Polarizing functional layer 13;

[0121] Multiple dichroic dye molecules 14 are disposed on the polarizing functional layer 13, and the angle between the stretching direction of the dichroic dye molecules 14 and the reference axis 12 is in the range of -5° to +5°.

[0122] In one embodiment of the present invention, the linear polarizer 10 serves to polarize light. The polarizing functional layer 13 is a polyvinyl alcohol (PVA) film. After dyeing, the PVA film adsorbs iodine molecules or dye molecules with biaxial absorption function. By stretching from both sides of the PVA film, the iodine molecules or dye molecules are arranged in an orderly manner on the PVA film, forming a polarizer with uniform biaxial absorption performance. The higher the degree of order of the iodine molecules or dye molecules, the higher the polarization degree of the formed polarizer. When the polarization degree of the polarizer exceeds 99%, a linear polarizer with a single polarization axis 11 is formed. In the polarizer 10, the stretching directions of iodine molecules and dye molecules on the polarizing functional layer 13 tend to be unified. When the polarization degree of the polarizer is low, the angle between the polarization axis 11 of the polarizer and the reference axis 12 will be within a preset range. This preset range is related to the polarization degree. The lower the polarization degree, the larger the preset range. At this time, the stretching directions of iodine molecules and dye molecules on the polarizing functional layer 13 form a preset angle with the reference axis 12, so that linearly polarized light with different polarization directions can be transmitted, thereby improving the transmittance of the circular polarizer 100 and improving the reflectivity of the reflective display panel.

[0123] The specific embodiments of this application have been described in detail above. The embodiments disclosed above are merely preferred embodiments of this application. Those skilled in the art can make many modifications and improvements without departing from the concept of this application. All such modifications and improvements fall within the scope of protection defined by the claims of this application.

Claims

1. A circular polarizer, characterized in that, include: A linear polarizer, wherein the angle between the polarization axis of the linear polarizer and the reference axis is in the range of -5° to +5°, and the reference axis is parallel to the straight line corresponding to one edge of the linear polarizer; and A phase retardation layer is disposed on one surface of the linear polarizer, and the phase retardation layer includes an odd number of quarter-wave plates with different optical axis orientations. The phase delay layer includes: A first quarter-wave plate is disposed on one surface of the linear polarizer; A second quarter-wave plate is disposed on a surface of the first quarter-wave plate opposite to the linear polarizer; and The third quarter-wave plate is disposed on a surface of the second quarter-wave plate that is opposite to the linear polarizer. The angle between the optical axis of two adjacent quarter-wave plates and the reference axis gradually increases or decreases along a direction perpendicular to the plane corresponding to the linear polarizer and away from the linear polarizer.

2. The circular polarizer as described in claim 1, characterized in that, The number of quarter-wave plates is greater than or equal to three, and an odd number of quarter-wave plates are stacked sequentially on one surface of the linear polarizer. The angle between the optical axis of the quarter-wave plate and the reference axis is in the range of -60° to +60°.

3. The circular polarizer as described in claim 2, characterized in that, The angle between the optical axis of the quarter-wave plate and the reference axis is in the range of +35° to +55°.

4. The circular polarizer as described in claim 3, characterized in that, The angle between the optical axis of the first quarter-wave plate and the reference axis in the clockwise direction is within the range of +35° to +45°; The optical axis of the second quarter-wave plate forms an angle of +40° to +50° with the reference axis in a clockwise direction; The optical axis of the third quarter-wave plate forms an angle of +45° to +55° with the reference axis in a clockwise direction; Wherein, the angle between the optical axis of the first quarter-wave plate and the reference axis in the clockwise direction is smaller than the angle between the optical axis of the second quarter-wave plate and the reference axis in the clockwise direction, and the angle between the optical axis of the second quarter-wave plate and the reference axis in the clockwise direction is smaller than the angle between the optical axis of the third quarter-wave plate and the reference axis in the clockwise direction.

5. The circular polarizer as described in claim 2, characterized in that, The angle between the optical axis of the quarter-wave plate and the reference axis is in the range of -35° to -55°.

6. The circular polarizer as described in claim 5, characterized in that, The angle between the optical axis of the first quarter-wave plate and the reference axis in the counterclockwise direction is within the range of -45° to -55°; The angle between the optical axis of the second quarter-wave plate and the reference axis in the counterclockwise direction is within the range of -40° to -50°; The angle between the optical axis of the third quarter-wave plate and the reference axis in the counterclockwise direction is within the range of -35° to -45°; Wherein, the angle between the optical axis of the first quarter-wave plate and the reference axis in the counterclockwise direction is greater than the angle between the optical axis of the second quarter-wave plate and the reference axis in the counterclockwise direction, and the angle between the optical axis of the second quarter-wave plate and the reference axis in the counterclockwise direction is greater than the angle between the optical axis of the third quarter-wave plate and the reference axis in the counterclockwise direction.

7. The circular polarizer as described in claim 1, characterized in that, The phase delay layer also includes a half-wave plate, which is stacked between the odd-numbered quarter-wave plates and the linear polarizer.

8. The circular polarizer as described in claim 1, characterized in that, The phase delay sheet layer also includes a half-wave plate, and the odd-numbered quarter-wave plates and the half-wave plates are sequentially stacked on one surface of the linear polarizer.

9. The circular polarizer as described in claim 1, characterized in that, The linear polarizer includes: Polarizing functional layer; and Multiple dichroic dye molecules are disposed in the polarizing functional layer, and the angle between the stretching direction of the dichroic dye molecules and the reference axis is in the range of -5° to +5°.

10. A reflective display panel, characterized in that, include: Array substrate; A reflective layer is disposed on the array substrate; A liquid crystal layer, wherein the liquid crystal layer is disposed on the reflective layer; Opposing substrate, the opposing substrate being disposed on the liquid crystal layer; and The circular polarizer as described in any one of claims 1-9; The circular polarizer is disposed on the opposing substrate, and the phase delay film layer is located between the opposing substrate and the linear polarizer.

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