Display module and display device

Abstract

This invention provides a display module and a display device. The display module includes a backlight module and a cover plate. The cover plate includes a display area and a frame area located on at least one side of the display area. A directional sound-emitting component is provided on the side of the cover plate away from the backlight module or the frame area along the thickness direction of the display module. The directional sound-emitting component is used to emit sound according to a preset sound-emitting angle. By setting a directional sound-emitting component on the display module, this invention can meet the audiovisual environment needs of passengers in different seats in a vehicle, thereby improving the riding experience of passengers in the vehicle.

Description

Technical Field

[0001] This invention relates to the field of display technology, and more specifically, to a display module and a display device. Background Technology

[0002] For car passengers, a pleasant in-car audiovisual environment is essential. For example, when the driver is using navigation, other passengers expect to be undisturbed by the navigation announcements, requiring a comfortable driving experience: a quiet place to rest, read, or even enjoy immersive entertainment. Similarly, when other passengers are using the secondary entertainment screen for movies or games, the driver should remain undisturbed, maintaining focus and avoiding distractions that could pose safety hazards.

[0003] Therefore, how to meet the individual audiovisual environment needs of passengers in different seats inside the vehicle is a problem we are currently facing.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a display module and display device that can meet the audiovisual environment needs of passengers in different seats in a vehicle, thereby improving the riding experience of passengers in the vehicle.

[0006] According to one aspect of the present invention, a display module is provided, including a backlight module and a cover plate, the cover plate including a display area and a frame area located on at least one side of the display area, the cover plate having a directional sound-emitting component disposed on a side of the backlight module or the frame area along the thickness direction of the display module, the directional sound-emitting component being used to emit sound according to a preset sound-emitting angle.

[0007] According to another aspect of the present invention, a display device is provided, comprising any of the above-described display modules.

[0008] The advantages of this invention compared to the prior art are as follows:

[0009] The display module and display device provided by the present invention can emit sound in a directional manner according to a preset sound angle by setting a directional sound-emitting component on the display module, thereby meeting the audiovisual environment needs of passengers in different seats in the vehicle, avoiding sound interference to unrelated personnel, and improving the riding experience of passengers in the vehicle. Attached Figure Description

[0010] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0011] Figure 1 This is a schematic diagram of the sound field diffusion direction inside a vehicle in an application scenario of existing technology.

[0012] Figure 2 This is a schematic diagram of the structure of a display module disclosed in an embodiment of the present invention;

[0013] Figure 3 This is a schematic diagram of the structure of the cover plate in a display module disclosed in an embodiment of the present invention;

[0014] Figure 4 This is a schematic diagram of the sound field diffusion direction inside a vehicle under the same application scenario, as disclosed in an embodiment of the present invention;

[0015] Figure 5 This is a schematic diagram of the structure of a display module disclosed in another embodiment of the present invention;

[0016] Figure 6 This is a top view of the array element distribution structure in a piezoelectric thin film transducer disclosed in an embodiment of the present invention;

[0017] Figure 7 This is a cross-sectional view of the array element distribution structure in a piezoelectric thin film transducer disclosed in an embodiment of the present invention;

[0018] Figure 8 This is a schematic diagram of the sound field radiation direction of a piezoelectric thin film transducer at different resonant frequencies, as disclosed in an embodiment of the present invention.

[0019] Figure 9 This is a schematic diagram of the structure of a microelectromechanical system transducer disclosed in an embodiment of the present invention;

[0020] Figure 10 This is a schematic diagram of the partitioned sound generation of each parametric array in the core layer of a microelectromechanical system transducer disclosed in an embodiment of the present invention.

[0021] Figure 11 This is a schematic diagram of the partitioned sound generation of each parametric array in the core layer of a microelectromechanical system transducer disclosed in another embodiment of the present invention. Detailed Implementation

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0023] It should be noted that specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0024] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0025] It should be noted that the directional terms such as "upper," "lower," "left," and "right" used in the embodiments of the present invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of the present invention. Furthermore, in the context, it should be understood that when it is mentioned that an element is formed "upper" or "lower" of another element, it can not only be formed directly "upper" or "lower" of the other element, but also indirectly "upper" or "lower" of the other element through an intermediate element.

[0026] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the figures denote the same or similar structures, and therefore repeated descriptions of them will be omitted. Terms describing position and direction in the present invention are illustrative based on the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of the present invention. The accompanying drawings of the present invention are only used to illustrate relative positional relationships; the layer thicknesses of certain parts are exaggerated in drawing style for ease of understanding, and the layer thicknesses in the drawings do not represent the actual proportional relationships of layer thicknesses. Furthermore, the embodiments and features in the embodiments of the present invention can be combined with each other unless otherwise specified. The accompanying drawings of the various embodiments in this application use the same reference numerals.

[0027] refer to Figure 1 In a current in-vehicle application scenario, referencing Figure 1 The sound field diffusion direction 11 shown in the diagram (assuming there is a display screen in front of each seat) is common in conventional in-vehicle audio-visual systems, meaning the sound field diffuses in all directions. When making phone calls or playing music, this can affect other passengers and even distract the driver, posing a safety hazard.

[0028] To address the aforementioned problems, this invention discloses a display module. (Reference) Figure 2 The display module includes a backlight module 21 and a cover plate 22 stacked together. (See reference) Figure 3 The aforementioned cover plate 22 includes a display area 31 and a bezel area 32 located on at least one side of the display area 31. The bezel area 32 of the cover plate is provided with a directional sound-emitting component. Alternatively, a directional sound-emitting component is provided on the side of the cover plate along the thickness direction of the display module, away from the backlight module. The aforementioned directional sound-emitting component is used to emit sound according to a preset sound-emitting angle. (Reference) Figure 4 The sound field diffusion direction 41 shown in the figure (assuming there is a display screen in front of each seat) enables directional sound emission from the display device screen, such as a car screen or a laptop screen, avoiding auditory interference to unrelated personnel and improving the user experience.

[0029] The principle of directional sound generation components is to utilize the high directivity, frequency superposition effect, and high-frequency attenuation effect of ultrasonic waves. By selecting ultrasonic waves of appropriate frequencies, their difference frequency signals are kept within the audible range to achieve directional sound generation.

[0030] The preset sound emission angle can be pre-generated, i.e., a fixed value; or it can be dynamically determined, i.e., the angle value can be dynamically adjusted. In some optional embodiments, the directional sound emission component includes a sound emission layer and a driving circuit layer connected to each other. The driving circuit layer is used to provide a driving signal to the sound emission layer. The sound emission layer obtains the preset sound emission angle based on the driving signal and emits sound according to the preset sound emission angle. In this embodiment, the preset sound emission angle can be dynamically determined based on the driving signal. The driving signal can be generated based on the sound emission angle input by the user in the interactive interface. In this case, the preset sound emission angle is the angle range input by the user; it can also be generated based on the viewing angle of the display module. For example, if the display module has a privacy function, in this case, the preset sound emission angle is the same as the viewing angle of the display module. When the privacy function is enabled, the viewing angle of the display module is smaller than the viewing angle in the non-privacy mode.

[0031] In some optional embodiments, in addition to directional sound emission from the display module, the display module has a sharing mode and a privacy mode. The light emission angle in the sharing mode is greater than that in the privacy mode. This allows for switchable sharing and privacy modes of the display screen, while the screen's sound emission can be directional as needed, and the sound field can be zoned and adjusted, switching between a wide-angle sound field and a directional sound field. This achieves a combination of screen sound emission and display, meaning that both the sound field and light field are directional, allowing the driver, front passenger, and rear passengers to have independent audio-visual spaces within the vehicle. Preferably, the screen's light emission angle in the privacy mode matches the directional sound emission angle of the directional sound component; this further enhances the user experience.

[0032] Furthermore, in some embodiments, the directional sound component can turn on or off the directional sound mode. When the directional sound mode is turned on, sound is emitted through the directional sound component; when the directional sound mode is turned off, sound is emitted through the device speaker. When the display module turns on the sharing mode, the above-mentioned directional sound component turns off the directional sound mode, that is, all passengers in the vehicle can hear the sound. When the display module turns on the anti-peeping mode, the above-mentioned directional sound component turns on the directional sound mode, and the audience of the directional sound is the same as that of the display module in the anti-peeping mode. In this way, the联动 control of display direction and sound direction is realized, so that all passengers in the vehicle have an independent audio-visual experience, which is beneficial to improving the experience of all passengers.

[0033] For example, when the display screen in front of the co-pilot passenger turns on the anti-peeping mode, the driver will not be affected by any visual and auditory interference at all, and can focus on driving the vehicle and the road information ahead. This is not only beneficial to improving the experience of the driver and passengers, but also beneficial to ensuring the safety of the vehicle. When the vehicle stops and the display screen in front of the co-pilot passenger turns on the sharing mode, the driver can watch the display content of the co-pilot screen together.

[0034] Embodiment 1

[0035] In this embodiment, the above-mentioned directional sound component is arranged in the border area of the cover plate. Refer to Figure 5 , the display module disclosed in this embodiment further includes a dual-refraction control type liquid crystal cell (Electrically Controlled Birefringence cell, ECB cell) module 23 located between the backlight module 21 and the cover plate 22. That is, in this embodiment, along the light-emitting direction of the display module, the display module sequentially includes a backlight module 21, a dual-refraction control type liquid crystal cell module 23, and a cover plate 22. Among them, the above-mentioned dual-refraction control type liquid crystal cell module 23 includes at least one dual-refraction control type liquid crystal cell. For the consideration of reducing the thickness of the display module, in some optional embodiments, the above-mentioned dual-refraction control type liquid crystal cell module includes one or two dual-refraction control type liquid crystal cells.

[0036] Among them, the above-mentioned directional sound component can be arranged only on one side of the display area, or can be arranged around multiple sides of the display area. For example, directional sound components are arranged on all four sides of the display area; this application does not limit this.

[0037] In this embodiment, based on the aforementioned birefringence-controlled liquid crystal cell module, the display module achieves both a sharing mode and a privacy mode. Specifically, the birefringence-controlled liquid crystal cell can adjust the shape of the internal liquid crystal, such as its tilt angle, through voltage to achieve different light emission angles, thereby realizing the sharing mode and privacy mode of the display module respectively. The light emission angle of the display module in sharing mode is greater than that in privacy mode. In a preferred embodiment, the birefringence-controlled liquid crystal cell module includes two birefringence-controlled liquid crystal cells stacked sequentially along the thickness direction of the display module, which narrows the viewing angle of the display module, thereby enhancing the privacy effect.

[0038] In this embodiment, the directional sound-emitting component is a piezoelectric thin-film transducer, and the backlight module is a local dimming light source, that is, it uses a direct-lit light source. The local dimming light source enables the privacy display module to achieve a pure black state, higher dynamic contrast, and clearer display, resulting in better display effects, especially in shared mode.

[0039] The piezoelectric film mentioned above can be, for example, a PVDF (polyvinylidene fluoride) film. (Reference) Figure 6 The piezoelectric thin-film transducer mentioned above includes multiple array elements 61. These array elements can be arranged in multiple rows at intervals to form a transducer bead array.

[0040] refer to Figure 7 In this embodiment, the array element 61 in the piezoelectric thin-film transducer includes a sound-emitting layer 71 and a driving circuit layer 72, which are connected by pins 73. The driving circuit layer 72 is used to drive the sound-emitting layer 71 to emit sound. The surface of the array element, i.e., the surface of the sound-emitting layer, is provided with fine openings for sound emission. It should be noted that... Figure 6 and Figure 7 Only three array elements in a piezoelectric thin film transducer are shown as an example, and the number of array elements in a piezoelectric thin film transducer is not limited thereto in this application.

[0041] The sound-emitting layer 71 includes a first matching layer, a second matching layer, an optically transparent adhesive, a first electrode, a piezoelectric layer, and a second electrode, sequentially stacked along its thickness direction. Exemplarily, the first matching layer can be a silicon oxide layer, the second matching layer can be a silicon film layer, and the piezoelectric layer can be polyvinylidene fluoride (PVDF). The first and second electrodes can be ITO (tin-indium oxide) electrodes. This application is not limited to the specific materials of the first matching layer, the second matching layer, the piezoelectric layer, and the two electrodes. Under the drive of an electric potential, the piezoelectric thin-film transducer causes the piezoelectric layer to vibrate and emit sound waves. Through the arrangement of the array of elements, a directional sound emission effect is achieved. The sides of the piezoelectric layer do not deform or displace during the vibration and sound wave emission process.

[0042] Both the first and second matching layers are used to improve the energy efficiency of ultrasonic waves propagating in the medium, thereby increasing the sound pressure level and propagation distance. Optically transparent adhesive is used to bond the second matching layer and the first electrode. The first and second electrodes provide a potential to the piezoelectric layer, and their polarities are opposite. The piezoelectric layer vibrates to generate sound when driven by the potential.

[0043] In some optional embodiments, the spacing between adjacent elements in the array is d, and the wavelength of the sound wave is λ, where d / λ ≤ 0.5. This effectively suppresses side lobes and grating lobes of the sound wave when the piezoelectric layer vibrates and emits sound, resulting in better sound wave directionality and improved directional sound emission from the directional sound-emitting component. For example, when the wavelength of the sound wave is 8.6 mm, the spacing between adjacent elements in the array is less than or equal to 4.3 mm. Preferably, the element spacing is 2.5 mm, in which case the directionality of the sound wave with a wavelength of 8.6 mm is even better.

[0044] In some alternative embodiments, reference Figure 8 As shown in the radiation direction curve 81, when the piezoelectric thin-film transducer operates at a resonant frequency of 40 kHz based on the driving signal provided by the driving circuit layer, the angle between the corresponding sound emission angle and the sound emission center line is less than or equal to 30°. This ensures that the directional sound emission component has good directionality within ±30° at a resonant frequency of 40 kHz. (Reference) Figure 8 In the radiation direction curve 82, when the resonant frequency of the piezoelectric thin-film transducer is 30kHz, the angle between the corresponding sound emission angle and the sound emission center line is less than or equal to 45°; this ensures that the directional sound emission component has good directionality within ±45° when the resonant frequency is 30kHz. The sound emission center line is perpendicular to the plane containing the frame area of ​​the cover plate.

[0045] In a preferred embodiment, reference Figure 8 In the radiation direction curve 83, the resonant frequency of the piezoelectric thin film transducer is 20kHz. In this case, the sound wave emitted by the vibration of the piezoelectric layer will not produce side lobes, resulting in better sound wave directionality.

[0046] In some alternative embodiments, an optical film may be included between the backlight module and the birefringence-controlled liquid crystal cell module along the light emission direction of the display module. A display cell may also be included between the birefringence-controlled liquid crystal cell module and the cover plate. This invention does not limit the structural composition of the display module.

[0047] For example, the width of the cover plate's frame area can be in the range of 13mm-14mm, preferably 13.58mm. The piezoelectric thin-film transducer can have 20 elements, each with a diameter of 10mm, a height of 8mm, and an element spacing of 15.32mm. It should be noted that this application does not limit the values ​​of the above parameters.

[0048] Example 2

[0049] In this embodiment, the aforementioned directional sound-emitting component is a piezoelectric thin-film transducer and is disposed in the frame area of ​​the cover plate. In specific implementation, the directional sound-emitting component may be disposed only on one side of the display area, or it may be disposed around multiple sides of the display area, such as directional sound-emitting components being disposed on all four sides of the display area; this application does not impose any restrictions on this.

[0050] In this embodiment, the array element in the piezoelectric thin-film transducer includes a sound-generating layer and a driving circuit layer, which are connected by pins. The driving circuit layer is used to drive the sound-generating layer to produce sound. The surface of the array element, i.e., the surface of the sound-generating layer, has fine openings for sound generation.

[0051] The sound-generating layer comprises a first matching layer, a second matching layer, an optically transparent adhesive, a first electrode, a piezoelectric layer, and a second electrode, stacked sequentially along its thickness direction. Exemplarily, the first matching layer may be a silicon oxide layer, the second matching layer may be a silicon film layer, and the piezoelectric layer may be polyvinylidene fluoride (PVDF). The first and second electrodes may be ITO (tin-indium oxide) electrodes. This application does not limit the specific materials of the first matching layer, the second matching layer, the piezoelectric layer, and the two electrodes. Under potential drive, the piezoelectric thin-film transducer causes the piezoelectric layer to vibrate and emit sound waves, achieving directional sound generation through the arrangement of the array of elements. The sides of the piezoelectric layer do not deform or displace during the vibration and sound wave emission process.

[0052] Both the first and second matching layers are used to improve the energy efficiency of ultrasonic waves propagating in the medium, thereby increasing the sound pressure level and propagation distance. Optically transparent adhesive is used to bond the second matching layer and the first electrode. The first and second electrodes provide a potential to the piezoelectric layer, and their polarities are opposite. The piezoelectric layer vibrates to generate sound when driven by the potential.

[0053] In some optional embodiments, the spacing between adjacent elements in the array is d, and the wavelength of the sound wave is λ, where d / λ ≤ 0.5. This effectively suppresses side lobes and grating lobes of the sound wave when the piezoelectric layer vibrates and emits sound, resulting in better sound wave directionality and improved directional sound emission from the directional sound-emitting component. For example, when the wavelength of the sound wave is 8.6 mm, the spacing between adjacent elements in the array is less than or equal to 4.3 mm. Preferably, the element spacing is 2.5 mm, in which case the directionality of the sound wave with a wavelength of 8.6 mm is even better.

[0054] In some optional embodiments, when the piezoelectric thin-film transducer operates at a resonant frequency of 40 kHz based on the driving signal provided by the driving circuit layer, the angle between the corresponding sound emission angle and the sound emission center line is less than or equal to 30°. This ensures that the directional sound emission component has good directionality within ±30° when the resonant frequency is 40 kHz. When the resonant frequency of the piezoelectric thin-film transducer is 30 kHz, the angle between the corresponding sound emission angle and the sound emission center line is less than or equal to 45°. This ensures that the directional sound emission component has good directionality within ±45° when the resonant frequency is 30 kHz. The sound emission center line is perpendicular to the plane containing the frame area of ​​the cover plate.

[0055] In a preferred embodiment, the resonant frequency of the piezoelectric thin film transducer is 20kHz. In this case, the sound waves emitted by the vibration of the piezoelectric layer will not produce side lobes, resulting in better sound wave directionality.

[0056] In some alternative embodiments, an optical film may be included between the backlight module and the birefringence-controlled liquid crystal cell module along the light emission direction of the display module. A display cell may also be included between the birefringence-controlled liquid crystal cell module and the cover plate. This invention does not limit the structural composition of the display module.

[0057] In this embodiment, the backlight module includes a stacked first backlight module and a second backlight module, with the light emission angle of the second backlight module being greater than that of the first backlight module. That is, the first backlight module provides a light source in privacy mode, and the second backlight module provides a light source in sharing mode, thus enabling free switching between privacy and sharing modes. In privacy mode, the first backlight module is on, and the second backlight module is off. In sharing mode, the second backlight module is on, and the first backlight module is off. Based on the above dual-backlight module structure, the display module achieves both sharing and privacy modes. The light emission angle of the display module in sharing mode is greater than that in privacy mode. Compared to the technical solution in Embodiment 1, which uses a local dimming light source and an ECB module, this embodiment's dual-backlight module solution offers better privacy performance.

[0058] The first backlight module can be composed of an LGP (Light Guiding Panel), a side-lit light source, an optical film, and an LCF (light control film).

[0059] In some optional embodiments, the display module may further include an electrically controlled birefringence cell (ECB cell) module disposed between the backlight module and the cover plate. That is, along the light emission direction of the display module, the display module sequentially includes a backlight module, a ECB cell module, and a cover plate. The ECB cell module includes at least one ECB cell. This embodiment, employing a display module technology combining a dual backlight module structure and an ECB module, offers better privacy protection compared to a solution using only a dual backlight module structure without an ECB module.

[0060] To reduce the thickness of the display module, in some optional embodiments, the birefringence-controlled liquid crystal cell module includes one or two birefringence-controlled liquid crystal cells. In a preferred embodiment, along the thickness direction of the display module, the birefringence-controlled liquid crystal cell module includes two birefringence-controlled liquid crystal cells stacked sequentially, which allows for a narrower viewing angle and enhanced privacy protection.

[0061] Example 3

[0062] In this embodiment, the aforementioned directional sound-emitting component is a micro-electro-mechanical system (MEMS) transducer disposed along the thickness direction of the display module on the side of the cover plate opposite to the backlight module, and the MEMS transducer covers the cover plate. That is, the MEMS transducer covers the entire upper surface of the cover plate, and all of the MEMS transducers on the entire surface can emit sound. This embodiment facilitates the achievement of a narrow bezel for the display module.

[0063] refer to Figure 9 The aforementioned microelectromechanical system transducer includes a first protective layer 91, a first conductive layer 92, a core layer 93, a second conductive layer 94, and a second protective layer 95, stacked sequentially along its thickness direction. The core layer 93 is a centrally vibrating thin film and has multiple parametric arrays. The first conductive layer 92 and the second conductive layer 94 are both electrically connected to the core layer and are used to provide a potential to the core layer to control the opening or closing of the sound emission from each parametric array, thereby achieving directional sound emission. Exemplarily, the first protective layer 91 and the second protective layer 95 can be made of PET (polyterephthalic acid) material; this application does not impose any limitation on this.

[0064] In this core layer 93, each parametric array can be independently controlled to emit sound via signals, thereby achieving zoned sound emission from the microelectromechanical system transducer. (Reference) Figure 10 and Figure 11 The parametric array in the core layer includes a first region 101, a second region 102, and a third region 103. Figure 10 In the middle, the first area 101, the second area 102 and the third area 103 all activated directional sound emission. Figure 11 In the middle, the first zone 101 and the third zone 103 have their directional sound emission turned off, while the second zone 102 has its directional sound emission turned on.

[0065] In practical applications, when the driver needs to answer a private call or other passengers need to rest, the acoustic parametric array in a specific zone can be controlled to emit sound, achieving a directional sound effect for the driver or other passengers. The directional sound-emitting component's sound angle can be switched between wide-angle and directional modes, and in conjunction with the display module, it can switch between anti-peeping mode and shared mode. This allows for application scenarios that simultaneously meet the driver's need to focus on driving and the entertainment needs of other passengers.

[0066] In this embodiment, the backlight module is a local dimming light source. Local dimming light sources enable the privacy display module to achieve a pure black in its black states, resulting in higher dynamic contrast, clearer display, and better display performance, especially in shared mode.

[0067] In this embodiment, the display module further includes an electrically controlled birefringence cell (ECB cell) module located between the backlight module and the cover plate. That is, in this embodiment, along the light emission direction of the display module, the display module sequentially includes a backlight module, an ECB cell module, and a cover plate. The ECB cell module includes at least one ECB cell. To reduce the thickness of the display module, in some optional embodiments, the ECB cell module includes one or two ECB cells.

[0068] Based on the aforementioned birefringence-controlled liquid crystal cell module, the display module achieves both a sharing mode and a privacy mode. Specifically, the birefringence-controlled liquid crystal cell can adjust the shape of the internal liquid crystal, such as its tilt angle, through voltage regulation to achieve different light emission angles, thereby realizing the sharing mode and privacy mode of the display module respectively. The light emission angle of the display module in sharing mode is greater than that in privacy mode. In a preferred embodiment, the birefringence-controlled liquid crystal cell module includes two birefringence-controlled liquid crystal cells stacked sequentially along the thickness direction of the display module, which narrows the viewing angle of the display module, thereby enhancing the privacy effect.

[0069] Example 4

[0070] In this embodiment, the aforementioned directional sound-emitting component is a micro-electro-mechanical system (MEMS) transducer disposed along the thickness direction of the display module on the side of the cover plate opposite to the backlight module, and the MEMS transducer covers the cover plate. That is, the MEMS transducer covers the entire upper surface of the cover plate, and all of the MEMS transducers on the entire surface can emit sound. This embodiment facilitates the achievement of a narrow bezel for the display module.

[0071] The aforementioned microelectromechanical system transducer includes a first protective layer, a first conductive layer, a core layer, a second conductive layer, and a second protective layer stacked sequentially along its thickness direction. The core layer is a vibrating thin film in the middle, and the core layer has multiple parametric arrays. The first and second conductive layers are both electrically connected to the core layer and are used to provide potential to the core layer to control the opening or closing of the sound emission of each parametric array, thereby achieving directional sound emission.

[0072] In this process, each parametric array in the core layer can be independently controlled to emit sound via signals, thereby achieving zoned sound emission from the microelectromechanical system transducer. The aforementioned first and second protective layers can be made of PET (polyterephthalic acid) material, and this application does not impose any restrictions on this.

[0073] In this embodiment, the backlight module is a dual backlight source, comprising a stacked first backlight module and a second backlight module. The light emission angle of the second backlight module is greater than that of the first backlight module. Specifically, the first backlight module provides a light source in privacy mode, and the second backlight module provides a light source in sharing mode, thus enabling free switching between privacy and sharing modes. In privacy mode, the first backlight module is on, and the second backlight module is off. In sharing mode, the second backlight module is on, and the first backlight module is off. Based on this dual backlight module structure, the display module achieves both sharing and privacy modes. The light emission angle of the display module in sharing mode is greater than that in privacy mode. Compared to the technical solutions in Embodiments 1 and 3 that use a regional dimming light source and an ECB module, the dual backlight module solution in this application provides better privacy performance.

[0074] The first backlight module can be composed of an LGP (Light Guiding Panel), a side-lit light source, an optical film, and an LCF (light control film).

[0075] In some optional embodiments, the display module may further include an electrically controlled birefringence cell (ECB cell) module disposed between the backlight module and the cover plate. That is, along the light emission direction of the display module, the display module sequentially includes a backlight module, a ECB cell module, and a cover plate. The ECB cell module includes at least one ECB cell. This embodiment, employing a display module technology combining a dual backlight module structure and an ECB module, offers better privacy protection compared to a solution using only a dual backlight module structure without an ECB module.

[0076] To reduce the thickness of the display module, in some optional embodiments, the birefringence-controlled liquid crystal cell module includes one or two birefringence-controlled liquid crystal cells. In a preferred embodiment, along the thickness direction of the display module, the birefringence-controlled liquid crystal cell module includes two birefringence-controlled liquid crystal cells stacked sequentially, which allows for a narrower viewing angle and enhanced privacy protection.

[0077] In some optional embodiments of this application, in addition to achieving directional sound emission from the display module, the display module has a shared mode and a privacy mode. When the display module is in shared mode, the directional sound emission component emits sound towards multiple sound emission angles. When the display module is in privacy mode, the directional sound emission component emits sound towards only one sound emission angle.

[0078] Furthermore, based on the above embodiments, the display module switches between a shared mode and a privacy mode based on the driver chip control. The directional sound-emitting component includes a sound-emitting layer and a driver circuit layer connected together. The driver circuit layer is used to drive the sound-emitting layer to emit sound. The driver circuit layer is electrically connected to the driver chip; thereby realizing the coordinated control of the display module and the directional sound-emitting component.

[0079] Specifically, in this embodiment, when the driver chip controls the display module to operate in shared mode, the driver circuit layer drives the sound-emitting layer to emit sound at multiple sound angles. When the driver chip controls the display module to operate in privacy mode, the driver circuit layer drives the sound-emitting layer to emit sound at one sound angle.

[0080] In some optional embodiments of this application, based on the directional sound emission of the display module, the display module has a sharing mode and a privacy mode. Furthermore, when the display module is in both sharing and privacy modes, the directional sound emission component emits sound only towards one sound angle, and the sound angle of the directional sound emission component in the corresponding sharing mode is greater than the sound angle in the corresponding privacy mode. That is, when the display module is in sharing mode, the directional sound emission component can, as needed, emit sound only towards a large sound angle; or, it can emit sound towards multiple small angles simultaneously.

[0081] It should be noted that all the embodiments disclosed in this application can be freely combined, and the resulting technical solutions are also within the protection scope of this application.

[0082] An embodiment of the present invention also provides a display device, which includes the display module described in the above embodiments. Detailed structural features and advantages of the display module can be found in the description of the above embodiments, and will not be repeated here.

[0083] It is understood that the type of display device can be any one of the following: Organic Light-Emitting Diode (OLED) display device, QLED (Quantum Dot Light Emitting Diodes) display device, or micro LED (μLED) display device, and the present invention does not specifically limit it in this regard.

[0084] The display device provided in the above embodiments can be any device that displays images, whether moving (e.g., video) or fixed (e.g., still images), and whether it contains text or images. More specifically, it is contemplated that the embodiments can be implemented in or associated with a variety of electronic devices. These various electronic devices include, but are not limited to, mobile phones, wireless devices, personal data assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, camcorders, game consoles, watches, clocks, calculators, television monitors, flat panel displays, computer monitors, automotive displays (e.g., odometer displays, etc.), navigators, cockpit controllers and / or displays, displays of camera views (e.g., displays of rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging and aesthetic structures, etc.

[0085] In summary, the display module and display device provided by the present invention have at least the following advantages:

[0086] The display module and display device disclosed in the embodiments of the present invention can emit sound in a directional manner according to a preset sound angle by setting a directional sound-emitting component on the display module, thereby meeting the audiovisual environment needs of passengers in different seats in the vehicle, avoiding sound interference to unrelated personnel, and improving the riding experience of passengers in the vehicle.

[0087] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A display module, characterized in that, The device includes a backlight module and a cover plate. The cover plate includes a display area and a frame area located on at least one side of the display area. The cover plate is provided with a directional sound-emitting component on the side opposite to the backlight module or the frame area along the thickness direction of the display module. The directional sound-emitting component is used to emit sound according to a preset sound-emitting angle. The display module has a sharing mode and a privacy mode. The light emission angle in the sharing mode is greater than that in the privacy mode. The directional sound-emitting component emits sound to multiple sound-emitting angles in the sharing mode and emits sound to one sound-emitting angle in the privacy mode. In the privacy mode, the preset sound-emitting angle is the same as the viewing angle of the display module. The backlight module includes a first backlight module and a second backlight module stacked together. The light emission angle of the second backlight module is greater than that of the first backlight module.

2. The display module as described in claim 1, characterized in that, The display module further includes a birefringence-controlled liquid crystal cell module located between the backlight module and the cover plate, the birefringence-controlled liquid crystal cell module including one or two birefringence-controlled liquid crystal cells.

3. The display module as described in claim 1, characterized in that, The directional sound-emitting component includes a sound-emitting layer and a driving circuit layer connected to each other. The driving circuit layer is used to provide a driving signal to the sound-emitting layer. The sound-emitting layer analyzes the driving signal to obtain a preset sound-emitting angle and emits sound according to the preset sound-emitting angle.

4. The display module as described in claim 1, characterized in that, The directional sound-emitting component is a piezoelectric thin-film transducer disposed in the frame area, and the piezoelectric thin-film transducer is arranged on at least one side of the frame area.

5. The display module as described in claim 4, characterized in that, The piezoelectric thin film transducer includes multiple array elements, with a spacing of d between adjacent array elements and a wavelength of λ for the sound wave, where d / λ≤0.

5.

6. The display module as described in claim 4, characterized in that, When the resonant frequency of the piezoelectric thin film transducer is 40kHz, the angle between the corresponding sound emission angle and the sound emission center line is less than or equal to 30°. When the resonant frequency of the piezoelectric thin film transducer is 30kHz, the angle between the corresponding sound emission angle and the sound emission center line is less than or equal to 45°.

7. The display module as described in claim 4, characterized in that, The piezoelectric thin film transducer includes a first matching layer, a second matching layer, an optically transparent adhesive, a first electrode, a piezoelectric layer, and a second electrode, which are stacked sequentially along its thickness direction.

8. The display module as described in claim 1, characterized in that, The directional sound-emitting component is a microelectromechanical system transducer disposed on the side of the cover plate away from the backlight module along the thickness direction of the display module, and the microelectromechanical system transducer covers the cover plate.

9. The display module as described in claim 8, characterized in that, The microelectromechanical system transducer includes a first protective layer, a first conductive layer, a core layer, a second conductive layer, and a second protective layer stacked sequentially along its thickness direction; the core layer has multiple parametric arrays, and the first conductive layer and the second conductive layer are both electrically connected to the core layer.

10. The display module as described in claim 1, characterized in that, The display module switches between the shared mode and the privacy mode based on the control of the driver chip; the directional sound component includes a connected sound-emitting layer and a driving circuit layer, and the driving circuit layer is used to drive the sound-emitting layer to emit sound. The driving circuit layer is electrically connected to the driving chip; When the driver chip controls the display module to work in shared mode, the driver circuit layer drives the sound-emitting layer to emit sound at multiple sound-emitting angles; When the driver chip controls the display module to work in privacy mode, the driver circuit layer drives the sound-emitting layer to emit sound at a sound-emitting angle.

11. A display device, characterized in that, Includes the display module as described in any one of claims 1-10.

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