A high-brightness anti-glare on-board display

Abstract

The application provides a high-brightness anti-dazzle type airborne display, and discloses a high-brightness anti-dazzle type airborne display, which belongs to the technical field of aviation display.The display comprises, from top to bottom, a polaroid, a color filter film, a liquid crystal layer, a TFT driving substrate, a first 1 / 4 wave plate, a Bragg reflection layer, a second 1 / 4 wave plate, a lower polaroid and a quantum dot backlight layer.The Bragg reflection layer and the double 1 / 4 wave plate construct a polarized light circulation system, the angle and wavelength selectivity of the Bragg reflection layer are utilized to reflect and reintroduce the circularly polarized light with a large off-axis viewing angle into the light path circulation, and the light with a normal viewing angle and a small off-axis viewing angle is efficiently transmitted.The narrow-band characteristics of the quantum dot backlight and the Bragg reflection work cooperatively to concentrate and converge the backlight energy on the normal viewing angle output.The application significantly improves the normal viewing angle brightness and light energy utilization rate, effectively suppresses environmental glare, provides clearer and more reliable visual information for pilots under the same power consumption, and is especially suitable for a primary flight display.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a high-brightness anti-glare airborne display. Background Technology

[0002] In the field of avionics, airborne displays serve as a crucial human-machine interface for pilots to obtain flight information, and their display performance directly impacts flight safety. However, cockpit ambient lighting is complex and variable, often facing direct or reflected intense sunlight or airport ground lighting, resulting in strong ambient glare. The primary flight display faces the pilot directly, and its viewing angle's display quality and clarity directly affect the efficiency of flight information acquisition and flight safety. It is the display unit pilots rely on most throughout the flight. However, traditional LCD displays, due to their inherent optical structure, suffer from insufficient brightness at the viewing angle, and light is significantly lost as it penetrates multiple optical films and liquid crystal layers. Under strong ambient light interference, screen content is "diluted," leading to a sharp decline in contrast and visibility, forcing pilots to exert more cognitive effort to identify information, increasing operational burden and safety risks.

[0003] Existing solutions for improving visibility have significant limitations. First, while simply increasing backlight power can temporarily boost brightness, it leads to a surge in power consumption, heat buildup, and shortened system lifespan, making it unsustainable in power-sensitive aerospace applications. Second, conventional anti-glare treatments (such as surface frosting) can scatter ambient light and reduce specular reflection, but they also scatter display light, resulting in decreased image clarity and a "cloudy" appearance, with limited contribution to improving frontal brightness. Third, while self-emissive technologies such as OLEDs offer advantages in contrast, their peak brightness under high ambient light conditions remains challenging, and they are constrained by high cost and lifespan limitations. Crucially, existing technologies generally lack the ability to efficiently focus backlight energy at the frontal viewing angle, failing to effectively suppress ineffective light leakage at wide viewing angles while achieving high frontal brightness—a key aspect of resisting ambient light interference and improving the visual signal-to-noise ratio.

[0004] At the level of optical control technology, structures based on the Bragg reflection principle offer the possibility of precise manipulation of angle and polarization light. However, traditional broadband backlight sources are difficult to efficiently match with the narrow-band characteristics of Bragg structures, limiting their efficiency in concentrating light energy utilization in full-color displays. Meanwhile, quantum dot display technology has attracted considerable attention due to its ability to emit light with extremely narrow half-width, high color purity, and precisely tunable wavelengths. This "narrow-band" light-emitting characteristic of quantum dots creates ideal conditions for their collaborative operation with Bragg reflection structures.

[0005] Therefore, there is an urgent need in this field for an innovative optical solution that can fully utilize the narrow-band characteristics of quantum dot backlighting and integrate it with polarization-selective optical elements such as Bragg reflection. The core objective is to concentrate and guide precious backlight energy to the highest possible output direction at the positive viewing angle. By achieving extremely high brightness at the positive viewing angle, interference from ambient light can be fundamentally suppressed, thus providing an onboard display solution that combines high brightness, low power consumption, and excellent anti-glare capabilities. This is precisely the key technical challenge that this invention aims to solve.

[0006] This invention aims to propose a high-brightness, anti-glare airborne display. By constructing a multi-layered optical architecture of "polarization filtering-Bragg reflection-optical path circulation," it efficiently focuses the narrow-band light emitted by quantum dot backlighting onto the positive viewing angle. The core of this display includes a polarization circulation system composed of a Bragg reflector layer and two quarter-wave plates. This system can recapture the light energy lost in traditional structures and convert it into positive viewing angle emitted light. Without increasing energy consumption, it improves the display brightness of the airborne display at the positive viewing angle, reduces glare, and can improve flight safety to some extent. Summary of the Invention

[0007] The purpose of this invention is to solve the above-mentioned problems by providing a high-brightness anti-glare airborne display.

[0008] The technical solution of this application is implemented as follows: In a first aspect, this application provides a high-brightness anti-glare airborne display, comprising, from top to bottom: a polarizer; a color filter; a liquid crystal layer; a TFT driving substrate; a first quarter-wave plate; a Bragg reflector layer composed of cholesteric liquid crystal; a second quarter-wave plate; a lower polarizer; and a quantum dot backlight layer; wherein, light emitted from the quantum dot backlight layer is converted into circularly polarized light after passing through the lower polarizer and the second quarter-wave plate in sequence, and the circularly polarized light is incident on the Bragg reflector layer; the Bragg reflector layer is configured to transmit the circularly polarized light incident at a normal viewing angle and a small off-axis viewing angle, and to reflect the circularly polarized light incident at a large off-axis viewing angle, so as to focus the light energy at a normal viewing angle for output.

[0009] The advantages or beneficial effects of the above technical solutions include at least the following: First, it significantly improves light energy utilization at the positive viewing angle and offers advantages in system power consumption: Traditional brightness enhancement solutions (such as increasing backlight power or adding brightness enhancement films) usually come at the cost of increased overall power consumption, higher costs, or sacrificed viewing angle range. This invention, however, constructs a closed-loop optical path of "polarization cycle—Bragg reflection—phase conversion," redirecting the "ineffective" polarized light blocked by the polarizer back to the optical system. Through the synergistic effect of the Bragg reflection layer and the quarter-wave plate, the polarization state is reversed and reused, ultimately converting into "effective" light energy available for output at the positive viewing angle, significantly reducing energy loss when the display emits light at large off-axis viewing angles. This means that while maintaining the same backlight power, it can significantly improve front brightness; or, while achieving the same brightness target, it has lower system power consumption. Second, this invention possesses excellent structural simplicity and technical adaptability: The Bragg reflection layer and quarter-wave plate used in this invention form a relatively independent optical enhancement unit, without relying on complex film stacking or backlight modification. It can be widely adapted to various display technology platforms based on liquid crystal modulation (such as conventional LCDs, quantum dot enhanced backlights, and Mini-LED backlight systems). This solution reconstructs the optical path by addressing the physical nature of polarized light recycling, rather than relying solely on increasing backlight intensity. It provides the entire industry with a simple, easy-to-integrate, and compatible general technical path for further improving the brightness at the positive viewing angle while maintaining low power consumption and high color gamut. Attached Figure Description

[0010] The accompanying drawings illustrate exemplary embodiments of the present application and, together with the description thereof, serve to explain the principles of the present application. These drawings are included to provide a further understanding of the present application and are incorporated in and constitute a part of this specification.

[0011] Figure 1 This is a schematic cross-sectional view of a positive viewing angle enhanced display based on quantum dot technology proposed in this invention.

[0012] Figure 2 This is a diagram showing the optical path and polarization state changes of a positive viewing angle enhancement display based on quantum dot technology proposed in this invention.

[0013] Figure 3 This is a comparison diagram of the viewing angle brightness distribution before and after the 550nm wavelength light proposed in this invention passes through the Bragg reflector layer. Detailed Implementation

[0014] To enable those skilled in the art to further understand the present invention, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the drawings are for illustrative purposes only and are not drawn to scale.

[0015] A cross-sectional structural schematic diagram of the present invention is shown below. Figure 1 As shown, the structure of the present invention, from top to bottom, consists of: a polarizer 1, a color filter 2, a liquid crystal layer 3, a TFT driver 4, a quarter-wave plate 5, a Bragg reflector layer 6, a quarter-wave plate 7, a polarizer 8, and a quantum dot backlight layer 9. Detailed Implementation

[0017] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While some embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this application. It should be understood that the drawings and embodiments of this application are for illustrative purposes only and are not intended to limit the scope of protection of this application.

[0018] It should be noted that, where there is no conflict, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0019] It should be understood that the term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc., mentioned in this application are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0020] It should be noted that the terms "one" and "more" used in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0021] The names of the messages or information exchanged between multiple devices in the embodiments of this application are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0022] Figure 1This is a cross-sectional structural diagram of a positive viewing angle enhancement display based on quantum dot technology proposed in this invention. By constructing an optical path structure that coordinates polarization cycling and Bragg reflection, precise control of the polarization state and propagation direction of the emitted light is achieved. The fast and slow axis directions of the quarter-wave plate 5 are configured at a specific angle with the transmission axis of the upper and lower polarizers 1. The reflection rotation direction and center wavelength of the Bragg reflection layer 6 are designed to match the luminescence characteristics of the quantum dot backlight 9, together forming an efficient positive viewing angle enhancement system.

[0023] Combination Figure 3 The optical modulation process of the present invention is shown below. The propagation and modulation process of light in the multilayer structure is described in detail below: For ease of description, the light wave with a wavelength of 550nm emitted by the quantum dot backlight layer 9 is taken as an example, and the parameters of each optical element are assumed to be as follows: the transmission axis of the lower polarizer 8 is 0°; the slow axis of the quarter-wave plate 7 (located on the backlight side) is -45°; the 550nm light wave will become right-handed circularly polarized light after passing through the polarizer 8 and the quarter-wave plate 7 in sequence, and will be incident on the Bragg reflector layer 6 from various angles.

[0024] Bragg reflector layer 6 is composed of dextrorotatory cholesteric liquid crystal, with a central reflection wavelength and reflection band both greater than 550 nm. When Bragg reflection occurs, the following conditions must be met:

[0025] Where λ(θ) is the Bragg reflection wavelength at the incident angle θ. is the average refractive index of the liquid crystal, P is the pitch of the cholesteric liquid crystal, which is the distance corresponding to the rotation of the liquid crystal molecules by 360°, and ne and no are the extraordinary and ordinary refractive indices of the liquid crystal, respectively. It can be seen from the above formula that the reflected wavelength will shift to the shorter wavelength direction as the incident angle increases (i.e., "blue shift"). Therefore, when right-handed circularly polarized light with a wavelength of 550nm is incident on Bragg reflector layer 6, the incident light at small off-axis angle and normal angle does not meet the Bragg reflection condition and will be transmitted. However, the Bragg reflection wavelength of right-handed circularly polarized light incident at large off-axis angle will become smaller. When the technical parameters are appropriate, it will meet the Bragg reflection condition and be reflected.

[0026] The slow axis of the quarter-wave plate 5 is 45°; the transmission axis of the polarizer 1 is 90°.

[0027] The optical path modulation process is mainly divided into two stages: Combined with appendix Figure 2 The optical path control process of the positive viewing angle enhanced display is mainly divided into two stages.

[0028] Phase 1: Backlight Polarization and Bragg Reflection Cycle Natural light from the quantum dot backlight layer 9 propagates upwards and is first converted into linearly polarized light with a specific polarization direction, namely 0° polarization, by the lower polarizer 8. The 0° polarized linearly polarized light is then converted into right-hand circularly polarized light by the first 1 / 4 wave plate 7. Thus, the backlight is prepared into right-hand circularly polarized light with a specific polarization state and incident on the Bragg reflector layer 6 at different angles.

[0029] Phase Two: Viewpoint Sorting and Photovoltaic Cycling When right-handed circularly polarized light is incident on Bragg reflector layer 6, light incident at small off-axis and normal angles is transmitted, and the transmitted light is still right-handed circularly polarized. Simultaneously, light incident at large off-axis angles is reflected, and the reflected light is also right-handed circularly polarized. The transmitted light from small and normal angles passes through upper quarter-wave plate 5, where the direction of light propagation remains essentially unchanged, but the polarization state is transformed into 0-degree linearly polarized light. This linearly polarized light continues to propagate, forming effective image light output. The reflected light (right-handed circularly polarized) from large off-axis angles passes again through quarter-wave plate 7 and is transformed into 0-degree linearly polarized light. This 0-degree linearly polarized light has the same transmission axis as polarizer 8 and will completely pass through polarizer 8 to enter quantum dot backlight layer 9. These light waves pass through quantum dot backlight layer 9 and display packaging structure, etc. (see appendix). Figure 3 (Not shown) After being scattered, it undergoes depolarization, becomes natural light again, and propagates upward, then re-enters the polarization process of "stage one".

[0030] The reflection loop paths in "Phase One" and "Phase Two" are connected end to end, forming a closed light energy recovery loop: ineffective large-angle light rays are repeatedly captured, converted and reused in this loop until their angle is modulated to a positive angle or a small off-axis angle and then transmitted out, ultimately being converted into effective angle light energy output, thereby significantly improving the system's light utilization efficiency and positive angle brightness.

[0031] Figure 3 This is an optical simulation comparison of the spectral brightness distribution before and after light with a wavelength of 550nm passes through the aforementioned positive viewing angle enhancement structure, as proposed in this invention. It can be seen that at a wavelength of 550nm, this structure significantly improves the brightness at the positive viewing angle (around 0°). The brightness distribution reaches its peak in the central region at 0°, while it relatively decreases at larger off-axis angles (such as greater than ±40°), exhibiting a brightness enhancement distribution characteristic centered on the positive viewing angle. This effectively improves the brightness at the positive viewing angle, enhances the display effect of the main flight display of the airborne display, and thus achieves the technical effects of high brightness and anti-glare.

[0032] In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0033] Those skilled in the art should understand that the above embodiments are merely for illustrative purposes and are not intended to limit the scope of this application. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of this application.

Claims

1. A high-brightness anti-glare airborne display, characterized in that, The components, from top to bottom, are: a polarizer (1); a color filter (2); a liquid crystal layer (3); a TFT driving substrate (4); a first quarter-wave plate (5); a Bragg reflector layer (6) composed of cholesteric liquid crystal; a second quarter-wave plate (7); a lower polarizer (8); and a quantum dot backlight layer (9). The light emitted from the quantum dot backlight layer (9) is converted into circularly polarized light after passing through the lower polarizer (8) and the second quarter-wave plate (7) in sequence. The circularly polarized light is incident on the Bragg reflector layer (6). The Bragg reflector layer (6) is configured to transmit the circularly polarized light incident at a normal viewing angle and a small off-axis viewing angle, and to reflect the circularly polarized light incident at a large off-axis viewing angle, so as to focus the light energy at a normal viewing angle for output. The Bragg reflector layer (6) is composed of cholesteric liquid crystal, and its central reflection wavelength and Bragg reflection band under normal incidence are both greater than the central wavelength of the light wave emitted by the quantum dot backlight layer (9); the incident light from the second 1 / 4 waveplate (7) is circularly polarized light incident on the Bragg reflector layer (6); wherein, the Bragg reflector layer (6) is transmitted under normal viewing angle and small off-axis viewing angle, while it is reflected by it under large off-axis viewing angle; The large off-axis circularly polarized light reflected by the Bragg reflector layer (6) is converted into linearly polarized light after passing through the second 1 / 4 wave plate (7), and returns to the quantum dot backlight layer (9) through the lower polarizer (8). After scattering and depolarization, it re-enters the optical path loop.

2. The high-brightness anti-glare airborne display according to claim 1, characterized in that, The circular polarization state of the incident light from the second quarter wave plate (7) is the same as that of the Bragg reflector (6).

3. The high-brightness anti-glare airborne display according to claim 1, characterized in that, The transmission axis of the lower polarizer (8) is at a 45° angle to the fast and slow axis of the second quarter wave plate (7), which is used to convert the linearly polarized light from the lower polarizer (8) into circularly polarized light.

4. The high-brightness anti-glare airborne display according to claim 1, characterized in that, The small off-axis and positive angle circularly polarized light transmitted by the Bragg reflector (6) is converted into 90° linearly polarized light after passing through the first 1 / 4 wave plate (5) and is transmitted by the polarizer (1).

5. The high-brightness anti-glare airborne display according to claim 1, characterized in that, The angle between the transmission axis of the polarizer (1) and the transmission axis of the lower polarizer (8) is 90°, and the angle between the slow axis of the first quarter wave plate (5) and the first quarter wave plate (7) is 90°.

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