CN118112874A

CN118112874A - Projection screen and projection display equipment

Info

Publication number: CN118112874A
Application number: CN202310193704.4A
Authority: CN
Inventors: 杨飞; 王瑶瑶; 戴洁; 邢哲
Original assignee: Qingdao Hisense Laser Display Co Ltd
Current assignee: Qingdao Hisense Laser Display Co Ltd
Priority date: 2022-11-30
Filing date: 2023-03-02
Publication date: 2024-05-31
Also published as: CN118112876A; CN118112875A; CN118112879A; CN118112873A; CN118112878A; CN118112877A

Abstract

The application provides a projection screen and projection display equipment, wherein the projection screen comprises a sound production screen with a sound production vibrating diaphragm, and a plurality of sound production cavities are arranged on one side of the sound production vibrating diaphragm: a frame connected with the periphery of the sound emitting screen: the piezoelectric ceramic plates are respectively arranged in the sounding cavities; the size, the material and the volume ratio of the sound emitting cavities are all or partially different, and the influence of the sound emitting cavities on the loudness of sound waves in different frequency bands is different. The piezoelectric ceramic piece is used for exciting the vibration of sound production vibrating diaphragm in the deformation process, and the combination of sound production cavity and piezoelectric ceramic piece of different volumes makes the sound production screen can realize the subregion sound production to realize the different audio frequency effects of high, middle and low respectively. Realize projection screen's sound production through the piezoceramics piece that sets up, overall structure is simple, and piezoceramics piece is littleer to the machine that projection screen produced shakes.

Description

Projection screen and projection display equipment

The present application claims priority from the chinese patent application of application number 202211525290.2 filed at month 11 and 30 of 2022, the entire contents of which are incorporated herein by reference.

Technical Field

The present application relates to the field of projection technologies, and in particular, to a projection screen and a projection display device.

Background

The projection display device is a device capable of projecting images or videos onto a curtain, corresponding video signals can be played through connection of different interfaces, and the projection curtain with the sound production function, which is configured with the projection display device to realize the sound production effect, is more and more widely applied, so that the projection is convenient, and the advantages of good sound production effect and the like are favored by users.

The projection display equipment with the screen sounding function mainly comprises a plate-type projection screen and an electromagnetic exciter arranged on the plate-type projection screen, and the plate-type screen is driven to vibrate through the electromagnetic exciter to realize sounding. The vibration mode of the electromagnetic exciter is as follows: the vibration in the opposite direction is carried out with the vibrating diaphragm attached to the electromagnetic exciter, and the electromagnetic exciter is characterized in that the vibration amplitude is large, so that when the electromagnetic exciter is applied to the plate-type projection screen, vibration limiting and fixing are needed to be carried out on the plate-type projection screen and the electromagnetic exciter respectively, wherein the limiting of the plate-type projection screen can be realized through a frame fixing component, and the limiting of the electromagnetic exciter is realized through adding a fixing piece on the back of the electromagnetic exciter.

However, with the continual pursuit of users for product miniaturization, portability, diversity, and flexibility, flexible projection screens are becoming increasingly popular. The electromagnetic exciter has large amplitude and self weight, and compared with the plate-type projection screen, the flexible projection screen has higher degree of freedom, so that good limit and fixation of the electromagnetic exciter cannot be realized, and the flatness of the flexible projection screen cannot be ensured. In addition, the amplitude of the electromagnetic exciter is larger, so that the flexible projection screen is driven to generate larger fluctuation, and the display effect of the flexible projection screen cannot be ensured.

In view of this, how to provide a sound generating scheme adapted to a flexible projection screen is a problem to be solved.

Disclosure of Invention

The embodiment of the application provides a projection screen and projection display equipment, which can enable the projection screen to have better sound effect, realize the improvement of full-band sounding and sound loudness of the projection screen, avoid the situation of damaging the projection screen due to the heavy weight of an electromagnetic exciter and reduce the dead weight of the projection screen.

In a first aspect, an embodiment of the present application provides a projection screen, including: the sound generating screen comprises a sound generating vibrating diaphragm; a plurality of sound generating cavities are arranged on one side of the sound generating vibrating diaphragm; the frame is connected with the periphery of the sound generating screen; the piezoelectric ceramic piece is arranged in the sounding cavity; the size, the material and the volume ratio of the sounding cavities are all or partially different, the volume ratio is the ratio of the volume of the piezoelectric ceramic piece to the volume of the sounding cavity, and the loudness influence of the sounding cavities on sound waves in different frequency bands is different. The sound emitting cavities with different sizes, materials and volume ratios are arranged, so that the sound waves emitted by the vibration of the piezoelectric ceramic plates are different in frequency band and loudness, and the widening of the sound emitting frequency band of the projection screen and the improvement of sound loudness are realized.

In some embodiments of the present application, the sounding diaphragm includes a display functional layer, an adhesive layer, and a flexible auxiliary sounding layer; the display function layer and the auxiliary sounding layer are attached to form a composite vibrating diaphragm structure through the adhesive layer, and the sounding cavity is arranged on one side, away from the display function layer, of the auxiliary sounding layer. The sound production vibrating diaphragm is laminated through gluing layer with display function layer and supplementary sound production layer and is formed compound vibrating diaphragm structure, and wherein display function layer can show the image that the projector projected, and the piezoelectric ceramic piece that sets up on supplementary sound production layer then can drive sound production vibrating diaphragm and the air column vibration in the sound production cavity when the vibration and carry out sound production.

In some embodiments of the present application, the volume of the sound emitting cavities of different sizes is different, and/or the shape of the sound emitting cavities of different sizes is different. Sounding cavities of different volumes can adjust the frequency band of sound emitted by the piezoelectric ceramic plates, and sounding cavities of different shapes can adjust the loudness of sound emitted by the piezoelectric ceramic plates to widen the sounding frequency band of the projection screen and improve sounding loudness.

In some embodiments of the present application, the sounding cavity includes a first sounding cavity for raising sounding loudness of a first frequency band and a second sounding cavity for reducing sounding loudness of a second frequency band, volumes and/or shapes of the first sounding cavity and the second sounding cavity are different, and a silencing layer is disposed in the second sounding cavity. Based on the characteristics of low-frequency-band sound waves emitted by the piezoelectric ceramic plates, such as low loudness and high loudness of high-frequency-band sound waves, the shape or the content of the sound emitting cavities with different sizes are improved, so that the loudness of the low-frequency-band sound waves is close to that of the high-frequency-band sound waves, and the problems of high-frequency-band sound waves such as harshness are reduced.

In some embodiments of the application, the sound damping layer comprises sound damping foam and/or sound damping wedges. Through set up amortization bubble cotton and/or amortization wedge in the second sound production cavity, reduce the loudness of the high-frequency channel sound wave that piezoceramics piece sent to improve projection screen's inconsistent problem of sound production loudness.

In some embodiments of the present application, the piezoelectric ceramic sheet includes a vibration plate and a piezoelectric ceramic material layer disposed on the vibration plate; the piezoelectric ceramic material layer is provided with an anode pin and a cathode pin; the positive electrode pin and the negative electrode pin are connected with a host signal output end; the electric signal frequencies accessed by the piezoelectric ceramic plates in different sounding cavities are all or partially different. The alternating current output by the host signal output end can enable the piezoelectric ceramic material layer to generate mechanical deformation, the piezoelectric ceramic material layer can drive the vibrating plate to vibrate, the vibrating plate can drive the sounding vibrating diaphragm to vibrate to make sound, and resonance sounding of the sounding vibrating diaphragm is achieved.

In some embodiments of the present application, the piezoelectric ceramic sheet is disposed on the sounding diaphragm; or the piezoelectric ceramic piece is arranged at one side of the sounding cavity, which is far away from the sounding vibrating diaphragm; or the piezoelectric ceramic piece is arranged in the middle of the sound-emitting cavity. The different setting positions of piezoceramics piece make piezoceramics piece vibration's effect different, and then widen sound production frequency channel and improve sound production loudness.

In some embodiments of the application, the frame comprises: an inner frame; the outer frame is used for wrapping the inner frame; the sound-producing vibrating diaphragm comprises a plurality of elastic connecting pieces, wherein each elastic connecting piece is provided with a first end and a second end which are opposite, the first end of each elastic connecting piece is connected with the edge of the sound-producing vibrating diaphragm, the second end of each elastic connecting piece is connected with the inner frame, and the elastic connecting pieces are used for flattening the sound-producing vibrating diaphragm through tension.

The frame that comprises inside casing and frame realizes the fixed of sound generating screen through the inside casing on the one hand, and on the other hand promotes projection screen overall structure's stability through the frame. In addition, the elastic connecting piece can flatten the sounding vibrating diaphragm through the pulling force, according to the elasticity size of the elastic connecting piece, the tensioning degree of the sounding vibrating diaphragm can be controlled, and then the sounding effect when the sounding vibrating diaphragm and the piezoelectric ceramic plate resonate is improved by adjusting the tensioning degree of the sounding vibrating diaphragm.

In some embodiments of the application, the inner frame is provided with a flange far away from the sound-emitting screen; the flange is attached to the hanging surface, so that the hanging surface and the sounding vibrating diaphragm are enclosed to form the sounding cavity. The sound generating cavity is formed by encircling the sound generating screen and the external wall body through the arrangement of the upper flange of the inner frame, so that the structure of the sound generating cavity can be simplified on the basis of ensuring the stable structure of the projection screen, and the improvement of the production assembly efficiency of products is facilitated.

In a second aspect, embodiments of the present application also provide a projection display device comprising a laser projector and any one of the projection screens described above; the laser projector is in communication connection with the projection screen.

Due to the adoption of the technical scheme, the technical scheme provided by the application at least has the following beneficial effects:

According to the projection screen provided by the embodiment of the application, the sounding of the projection screen is realized through the plurality of sounding cavities and the piezoelectric ceramic plates arranged on the sounding screen, the whole structure is simple, the projection screen is lighter and thinner, and compared with an electromagnetic exciter, the piezoelectric ceramic plates have smaller mechanical vibration on the projection screen. In addition, through setting up piezoceramics piece in the sound emitting cavity, borrow the influence of sound emitting cavity to the sound frequency channel, can make the sound of specific frequency channel that specific piezoceramics piece excitation sound emitting vibrating diaphragm produced shift. And moreover, the piezoelectric ceramic plates with the same structure and the sounding cavities with different structures can enable sounds emitted by the sounding screen to have various different frequency bands, and the sounds can be shifted in the different frequency bands. Finally, through the cooperation between a plurality of sound producing cavities and the sound producing areas that piezoceramics piece produced on the sound producing vibrating diaphragm, realize the full-band sound production of sound producing screen, improve the sound producing effect of sound producing screen greatly, make the sound that projection screen produced have wider frequency channel and better high bass audio, promote user's audio-visual experience.

The embodiment of the application also provides projection display equipment, which enables a user to receive wider frequency band sound in the process of watching the video through the full frequency band sounding effect brought by the projection screen, thereby adding the feeling of being on the scene and greatly pleating the video watching experience of the user.

Drawings

FIG. 1 is a schematic illustration of a projection display device according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a display function layer according to an embodiment of the present application;

FIG. 3 is a schematic view of a projection screen according to an embodiment of the present application;

FIG. 4 is an exploded view of a projection screen according to an embodiment of the present application;

FIG. 5 is a schematic view of a frame according to an embodiment of the present application;

FIG. 6 is a schematic structural view of an elastic connector according to an embodiment of the present application;

FIG. 7 is a schematic diagram of an auxiliary sounding layer of a projection screen according to an embodiment of the present application;

FIG. 8 is a schematic diagram of a mounting structure of a piezoelectric ceramic plate and a cavity housing according to an embodiment of the present application;

FIG. 9 is a schematic diagram of an installation structure of a piezoelectric ceramic plate and a cavity casing according to another embodiment of the present application;

FIG. 10 is a schematic view of a multilayer piezoelectric ceramic layer according to an embodiment of the present application;

Fig. 11 is a schematic structural diagram of a piezoelectric ceramic sheet according to an embodiment of the present application.

Detailed Description

Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The embodiments described in the examples below do not represent all embodiments consistent with the application. Merely exemplary of systems and methods consistent with aspects of the application as set forth in the claims.

It should be noted that the brief description of the terminology in the present application is for the purpose of facilitating understanding of the embodiments described below only and is not intended to limit the embodiments of the present application. Unless otherwise indicated, these terms should be construed in their ordinary and customary meaning.

The terms first, second, third and the like in the description and in the claims and in the above-described figures are used for distinguishing between similar or similar objects or entities and not necessarily for describing a particular sequential or chronological order, unless otherwise indicated. It is to be understood that the terms so used are interchangeable under appropriate circumstances.

The terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a product or apparatus that comprises a list of elements is not necessarily limited to all elements explicitly listed, but may include other elements not expressly listed or inherent to such product or apparatus.

The term "module" refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware or/and software code that is capable of performing the function associated with that element.

The projection screen provided by the embodiment of the application can be applied to various types of projectors. The projector is a device capable of projecting images or videos on a screen, and can play corresponding video signals through different interfaces in connection with a computer, a broadcasting network, the Internet, a VCD (Video Compact Disc: video high-density optical disc), a DVD (DIGITAL VERSATILE DISC Recordable: digital video disc), a game machine, DV and the like. Projectors are widely used in homes, offices, schools, entertainment venues, etc., including laser projectors, CRT (Cathode Ray Tube) projectors, LCD (Liquid CRYSTAL DISPLAY) projectors, DLP (DIGITAL LIGHT Processing) projectors, etc.

Fig. 1 is a schematic layout diagram of a projection display device according to an embodiment of the present application.

In some embodiments, referring to fig. 1, the present application provides a projection display device including a projection screen and a laser projector, wherein the projection screen is fixed at a first position, and the projector is placed at a second position so that a picture projected by the projector coincides with the projection screen. The laser projector comprises a laser light source, a light machine, a lens and a projection medium. The laser light source provides illumination for the optical machine, the optical machine modulates light beams of the light source, outputs the light beams to the lens for imaging, and projects the light beams to the projection medium to form a projection picture.

In some embodiments, the laser light source of the laser projector comprises a laser component and an optical lens component, and a light beam emitted by the laser component can penetrate through the optical lens component to provide illumination for the optical machine. Wherein, for example, the optical lens assembly requires a higher level of environmental cleanliness, hermetic level of sealing; and the chamber for mounting the laser assembly can be sealed by adopting a dustproof grade with a lower sealing grade so as to reduce the sealing cost.

In some embodiments, the optics of the laser projector may include a heat dissipation system, a circuit control system, and the like. It should be noted that, in some embodiments, the light emitting component of the laser projector may also be implemented by an LED (LIGHT EMITTING Diode) light source.

In some embodiments, the laser light source in the laser projector may include a blue laser, a red laser and a green laser which are independently arranged, and the laser projector may also be referred to as a trichromatic laser projector, where the blue laser, the red laser and the green laser are all module lightweight (Mirai Console Loader, MCL) packaged lasers, which are small in size and facilitate compact arrangement of the optical paths.

In some embodiments, the laser projector includes a controller including at least one of a central processing unit (Central Processing Unit, CPU), a video processor, an audio processor, a graphics processor (Graphics Processing Unit, GPU), RAM Random Access Memory, RAM), a ROM (Read-Only Memory), a first to nth interface for input/output, a communication Bus (Bus), and the like.

In some embodiments, the laser projector may be configured with a camera for cooperating with the laser projector to effect regulatory control of the projection process. For example, the laser projector configured camera may be embodied as a 3D camera, or a binocular camera; when the camera is implemented as a binocular camera, the camera specifically includes a left camera and a right camera; the binocular camera can acquire images and play contents presented by a screen corresponding to the laser projector, namely the projection surface, and the images or the play contents are projected by a light machine built in the projection equipment.

When the laser projector moves to a position, the projection angle and the projection plane distance of the laser projector are changed, so that the projection image is deformed, and the projection image is displayed as a trapezoid image or other malformed images; the laser projector controller can realize automatic trapezoid correction based on the image shot by the camera through coupling the included angle between the projection surfaces of the optical machine and the correct display of the projected image.

In some embodiments, the projection screen is a screen capable of emitting sound, and is applied to a projection display device for displaying a projection picture projected by a laser projector. Referring to fig. 2, fig. 2 is a schematic structural diagram of a display function layer according to an embodiment of the application. In some embodiments, as shown in FIG. 2, the projection screen includes a display function layer, i.e., a visualization layer that carries an optical film. The display function layer sequentially includes, from the user viewing direction, i.e., from left to right in fig. 2: a surface layer 1, a coloured layer 2, a diffusing layer 3, a fresnel micro-lens layer 4, a reflecting layer 5 and a support structure 6. In the projection process, light emitted by the ultra-short focal projection equipment is refracted, enters the display functional layer, is reflected by the Fresnel micro lens layer 4 and then exits from the surface layer 1, finally enters human eyes, and is passively developed. Wherein the back side of the fresnel microlens layer 4 is coated with an aluminum reflective layer.

Currently, projection screens can be classified into a panel type projection screen and a flexible projection screen according to their own structures. The panel projection screen mainly comprises a display functional layer with a diaphragm, an adhesive layer, an auxiliary sounding layer, a frame, a cover plate, a suspension bracket, a damping layer, an electromagnetic exciter and the like, wherein the display functional layer is used for displaying a projection picture, the display functional layer, the adhesive layer, the auxiliary sounding layer, the damping layer and the electromagnetic exciter are sequentially connected to form a sounding screen, and the frame, the cover plate and the suspension bracket are of supporting structures and are used for fixing the sounding screen. Flexible projection screens typically include a display function layer having a membrane, an auxiliary sound-emitting layer, and a frame. If the electromagnetic exciter is directly applied to the flexible projection screen, the electromagnetic exciter is light and thin due to the heavy weight of the electromagnetic exciter, and the auxiliary sounding layer cannot support and fix the electromagnetic exciter, and cannot sound the flexible projection screen.

The piezoelectric ceramic plate has the characteristics of light weight, thin thickness, low power consumption, small amplitude and the like, and has excellent medium-high frequency tone. When the piezoelectric ceramic plate is applied to the flexible projection screen, on one hand, the piezoelectric ceramic plate is simple in structure, so that the piezoelectric ceramic plate can be fixed by selecting a proper adhesive material, and the fixation is realized without the need of matching structures such as a frame, a cover plate and the like an electromagnetic exciter, so that the projection screen with the sounding structure is lighter in dead weight, simpler and more convenient in processing and overhaul processes, and the reduction of product cost is facilitated; on the other hand, when the ceramic material layers in the piezoelectric ceramic sheet are fewer, the sounding frequency band is narrower, and the sounding frequency band is biased to high frequency; when the ceramic material layers in the piezoelectric ceramic plates are more, the sounding frequency band is widened, and the sounding frequency band is biased to low frequency; therefore, expansion of the sounding frequency band can be achieved by selecting piezoelectric ceramic plates with different numbers of ceramic material layers. In order to ensure that sound has a wider frequency band and better loudness, the embodiment of the application further improves the sounding loudness of the piezoelectric ceramic plate through the arrangement of the sounding cavity, so that the frequency response curve corresponding to the sound finally emitted by the projection screen is in the target range.

The target range refers to a range in which the frequency band corresponding to sound is wide enough and the loudness is uniform enough in a frequency response curve with the frequency band on the abscissa and the loudness on the ordinate, for example, the frequency band is 60-18000Hz, and the difference of the loudness is 10-20 dB.

In view of this, the embodiment of the application uses the piezoelectric ceramic plate as an excitation source, and combines the sound-producing structure based on the piezoelectric ceramic plate with the flexible projection screen with different structures, thereby realizing sound production of the flexible projection screen, and further meeting the personalized demands of users to the greatest extent.

According to the projection screen provided by the embodiment of the application, the sound production of the flexible projection screen is realized through the piezoelectric ceramic plates arranged on the sound production screen, the whole structure is simple, and the projection screen is lighter and thinner. Compared with the mode of using an electromagnetic exciter as an excitation source, the embodiment of the application uses the piezoelectric ceramic plate as the excitation source, and the piezoelectric ceramic plate has smaller weight compared with the electromagnetic exciter, so that the sounding structure can be suitable for flexible projection screens with various structures. In addition, compared with an electromagnetic exciter, the piezoelectric ceramic plate has smaller mechanical vibration generated by the projection screen, so that when the piezoelectric ceramic plate is fixed in a bonding mode, the bonding between the piezoelectric ceramic plate and the auxiliary sounding layer or the display functional layer is tighter, the situation that the piezoelectric ceramic plate and the auxiliary sounding layer or the display functional layer are possibly subjected to glue spreading due to stress fatigue and the like is reduced, and the self structural stability of the projection screen is guaranteed.

In addition, the embodiment of the application can also change the structure composition (such as the number, arrangement mode, type, self structure and the like of the piezoelectric ceramic plates) of the piezoelectric ceramic plates, change the self structure of the sound emitting screen, and form different types of sound emitting diaphragms in the projection screen through the cooperation between the piezoelectric ceramic plates and the sound emitting screens with different structures, so that the sound emitted by the projection screen has different frequency band broadening effects, the frequency response range of the sound is widened, the full-frequency band sound emission of the projection screen is realized, the sound generated by the projection screen has better high-low sound effect, the sound emitting effect of the sound emitting screen is greatly improved, and the audiovisual experience of a user is improved.

Referring to fig. 3 and 4, in some embodiments of the present application, a projection screen is provided that may include a sound emitting screen 100, a frame 200, and a piezoceramic sheet 310 and a sound emitting cavity 300. The sound generating screen 100 comprises a sound generating vibrating diaphragm, a plurality of sound generating cavities 300 are arranged on one side of the sound generating vibrating diaphragm, the frame 200 is connected with the periphery of the sound generating screen 100, the piezoelectric ceramic plates 310 are arranged in the sound generating cavities 300, and at least one piezoelectric ceramic plate 310 is arranged in each sound generating cavity 300.

For example, the sound generating cavity 300 may be formed by attaching the cavity housing 320 to the sound generating diaphragm, where the cavity housing 320 covers the corresponding piezoelectric ceramic plate 310 so that the piezoelectric ceramic plate 310 is located in the sound generating cavity 300. Because one side of the sounding diaphragm is provided with a plurality of sounding cavities 300, the number of the piezoelectric ceramic plates 310 and the number of the cavity shells 320 are also a plurality. In some embodiments, in order to make the piezoelectric ceramic plates 310 vibrate to emit sounds with different frequency bands and different loudness, the structure of each piezoelectric ceramic plate 310 may be the same, the sizes of the multiple sound emitting cavities 300 (cavity shells 320) are all or partially different, and the volume ratios of the multiple sound emitting cavities 300 with different sizes and the corresponding piezoelectric ceramic plates 310 are different, so as to broaden the frequency band of the sound emitted by the piezoelectric ceramic plates 310. It should be understood that the volume ratio is the ratio of the volume of the piezoelectric ceramic sheet 310 to the volume of the sound emitting cavity 300 (or cavity housing 320).

In some embodiments, when the piezoelectric ceramic plate 310 vibrates and sounds in the sound generating cavity 300, the manufacturing materials and shapes of the sound generating cavity 300 also affect the loudness and frequency band of the sound generated by the piezoelectric ceramic plate 310, so that when the sound generating cavity 300 compensates the sound loudness and widens the sound frequency band of the piezoelectric ceramic plate 310, the manufacturing materials and shapes of the plurality of sound generating cavities 300 (cavity shells 320) can be all or partially different to adjust the frequency band and the loudness of the vibration and sound generated by the same piezoelectric ceramic plate 310.

In addition, in some embodiments, the sounding diaphragm may include a display functional layer 110, an adhesive layer 120 and a flexible auxiliary sounding layer 130, where the auxiliary sounding layer 130 is attached to the display functional layer 110 through the adhesive layer 120 to form a composite diaphragm structure. For example, when the sound emitting cavity 300 is provided, the cavity housing 320 may be disposed on the side of the auxiliary sound emitting layer 130 away from the display function layer 110, the cavity housing 320 and the attached auxiliary sound emitting layer 130 together form the sound emitting cavity 300, and at least one piezoelectric ceramic piece 310 is disposed inside.

In some embodiments, the piezoelectric ceramic piece 310 may be disposed on the sounding diaphragm in other manners, for example, a through hole may be disposed on the auxiliary sounding layer 130, and the piezoelectric ceramic piece 310 passes through the through hole and is attached to the display functional layer 110 through the adhesive layer 120, so that the piezoelectric ceramic piece 310 can drive the sounding diaphragm to vibrate and sound; for another example, the piezoelectric ceramic sheet 310 may be disposed between the display function layer 110 and the auxiliary sound emitting layer 130; for another example, the piezoelectric ceramic piece 310 may be disposed on the side of the auxiliary sounding layer 130 far away from the display function layer 110, and a flange is disposed on the frame 200 far away from the sounding diaphragm, and after the projection screen is hung on the hanging surface, the flange, the hanging surface and the sounding diaphragm may be combined into the sounding cavity 300, so that the piezoelectric ceramic piece 310 may drive the air column and the sounding diaphragm in the sounding cavity 300 during sounding by vibration. The above arrangement is only a few possible arrangements of the sound generating cavity 300 and the piezoelectric ceramic plate 310 in the present application, and the present application is not limited to the combination of the sound generating diaphragm, the sound generating cavity 300 and the piezoelectric ceramic plate 310.

If the display function layer 110 is bonded to the piezoelectric ceramic sheet 310, a protective coating is required to be provided on the display function layer 110 at a bonding position with the piezoelectric ceramic sheet 310 to avoid damaging the display function layer 110 when the piezoelectric ceramic sheet 310 is electrically vibrated.

It is noted that, since the piezoelectric ceramic plate is limited by the process technology, the sounding frequency band is narrower, and most piezoelectric ceramic plates are used as buzzers. Therefore, in some embodiments of the present application, the piezoelectric ceramic sheet 310 is not a conventional piezoelectric ceramic sheet, but is made by a multi-layer ceramic structure and a low-temperature sintering technology of the piezoelectric ceramic, so that the sounding frequency band is expanded, and the piezoelectric ceramic and the metal can be welded or integrally formed, so that the preparation process is simple, the process conditions and requirements are correspondingly reduced, and the production cost can be saved while the sounding effect is improved. And combining the piezoelectric ceramic sounding with the laser projection screen to realize the polymorphic laser projection sounding screen.

Referring to fig. 10 and 11, in some embodiments, each piezoceramic sheet 310 may include a plurality of piezoceramic material layers 311, each piezoceramic material layer 311 is provided with a positive pin 3111 and a negative pin 3112, and the positive pin 3111 and the negative pin 3112 are connected to a host signal output. The positive electrode pin 3111 and the negative electrode pin 3112 may mechanically deform the piezoelectric ceramic material layer 311 according to alternating current provided by a host signal, and the piezoelectric ceramic material layer 311 excites the sound emitting screen 100 to vibrate to emit sound.

In other examples, each of the piezoelectric ceramic plates 310 may further include a vibration plate 312, the vibration plate 312 has a first side and a second side opposite to each other, the plurality of piezoelectric ceramic material layers 311 are disposed on the first side of the vibration plate 312, the second side of the vibration plate 312 is glued to the back surface of the sound generating screen 100, when the piezoelectric ceramic material layers 311 are mechanically deformed, the piezoelectric ceramic material layers 311 drive the vibration plate 312 to vibrate, and the vibration plate 312 excites the sound generating screen 100 to vibrate to generate sound.

The sounding principle of the piezoelectric ceramic piece is as follows: the piezoelectric ceramic material layer is attached to the vibrating plate, and is deformed in the direction perpendicular to the plane of the ceramic material layer after being electrified, and then the vibrating plate is driven to vibrate in the same direction; the bonding may be close bonding or non-close bonding, as long as a connection point is formed between the vibration plate and the piezoelectric ceramic material layer, the degree of tightness of the bonding is related to the noise formed finally, and the more close the bonding is, the less noise is. The piezoelectric ceramic plate has the characteristics of light weight and thin thickness, and has excellent medium-high frequency tone, thinner appearance structure and lower power consumption, so that the piezoelectric ceramic plate can be well matched with the sound emitting screen, and the flexible projection screen in the embodiment of the application has good sound effect. In addition, the embodiment of the application can also set the piezoelectric ceramic material layers into a multi-layer structure, so that the sounding frequency band of the piezoelectric ceramic sheet formed by the multi-layer piezoelectric ceramic material layers is expanded, and finally, the sounding of a wider frequency band of the flexible projection screen is realized. And moreover, the multi-layer piezoelectric ceramic material layer can be welded with metal or integrally formed with metal, so that the preparation process difficulty of the piezoelectric ceramic sheet is reduced.

It should be noted that, because the volumes and/or shapes of the sound generating cavities 300 with different sizes are different, and the sound generating ceramic plates 310 need to drive the air column and the cavity housing 320 in the sound generating cavity 300 to vibrate and generate sound in the sound generating process, the sound generating effects of the piezoelectric ceramic plates 310 with the same volume in different sound generating cavities 300 are different. For example, the piezoelectric ceramic plate 310 has a larger volume of the cavity shell 320 and the air column in the cavity, which need to be driven in the sounding cavity 300 with a larger volume, and the frequency of the emitted sound is lower; the piezoelectric ceramic piece 310 has smaller volume of the cavity shell 320 and the air column in the cavity, which need to be driven in the sounding cavity 300 with smaller volume, and the frequency of the sounding sound is higher.

During operation, the sounding ceramic sheet 310 mainly vibrates to drive the sounding diaphragm and the sounding cavity 300 to resonate, so as to realize a sounding effect. The sounding ceramic sheet 310 is energized to vibrate and transmits the vibration to the sounding diaphragm and the sounding cavity 300 through a contact area with the sounding diaphragm or the sounding cavity 300, so that the entire vibration of the sounding screen is realized to achieve the sounding effect. In the process of electrifying and vibrating the sounding ceramic sheet 310, the sounding ceramic sheet 310 can also drive the air column inside the sounding cavity 300 to vibrate to form a resonant cavity, and because in some embodiments, the sounding ceramic sheets 310 are all or partially different in size, and the sounding ceramic sheets 310 are identical in size, the volumes of the air columns directly affected by the vibration of the sounding ceramic sheets 310 in the sounding cavities 300 with different sizes are different, so that when the sounding ceramic sheets 310 apply vibration, the amplitudes and the vibration frequencies of the air columns with different volumes are different, and the sound frequency band can be widened by combining the sounds with different amplitudes and vibration frequencies.

In some embodiments, the sounding cavity 320 is formed by enclosing the cavity housing 320 and the sounding diaphragm, so when the shapes of the cavity housings 320 are different, the structure of the sounding cavities 300 is determined to be different, and the shape of the sounding cavity 300 can be set according to the needs. For example, if the opening direction of the cavity housing 320 is taken as the front, the front view of the sound emitting cavity 300 may be rectangular, square, circular or other shape, and the shape of the sound emitting cavity 300 is rectangular, trapezoidal or square when the sound emitting cavity 300 is viewed from above. The shape of the different sound generating cavities 300 also corresponds to the shape of the air column in the sound generating cavities 300, and different vibration effects can be generated by different air columns during vibration, so that different sound effects are realized. Similarly, the volume of the air column in the sound generating cavity 300 can be affected by the different volumes of the sound generating cavity 300, so that different sound effects can be realized.

When the sounding ceramic chip 310 performs low-frequency vibration sounding due to the sounding principle, the area of the sounding diaphragm, the air cylinder volume and the size of the cavity shell 320 which need to be driven are larger, the amplitude generated by the vibration of the sounding ceramic chip 310 is smaller, and the loudness of the low-frequency sound emitted by the vibration of the sounding ceramic chip 310 is smaller; when the high-frequency vibration sounding is performed, the size of the sounding diaphragm area, the size of the air cylinder and the size of the cavity shell 320 which need to be driven are smaller, the amplitude generated by the vibration of the sounding ceramic plate 310 is larger, and meanwhile, the loudness of the high-frequency sound emitted by the vibration of the sounding ceramic plate 310 is larger due to the structural characteristics of the sounding ceramic plate 310.

In some embodiments, the volume and the mass of the piezoelectric ceramic plate 310 are far smaller than those of the sounding diaphragm, when the piezoelectric ceramic plate 310 operates, the vibration generated by the piezoelectric ceramic plate 310 is difficult to drive the sounding diaphragm to vibrate with larger amplitude, and when the area needing to be affected by the piezoelectric ceramic plate 310 is larger, the vibration amplitude generated by the sounding diaphragm can be smaller. Therefore, the low-frequency sound producing effect of the piezoelectric ceramic plate 310 is poor, so that the low-frequency sound producing loudness of the screen is inconsistent with the high-frequency sound producing loudness.

Therefore, in some embodiments, a certain compensation needs to be made for the low-frequency band sounding in the projection screen, so as to improve the sounding effect of the sounding screen. In the present embodiment, the sound emitting structure of the plurality of sound emitting cavities 300 is different from the single cavity structure. The single-cavity structure mainly has the effect of loudness enhancement, and the vibration film and the air column can be formed by the single-cavity structure to amplify sound. In the structure of the multiple sound generating cavities 300 of the present application, the piezoelectric ceramic plates 310 and the sound generating cavities 300 can be matched to form a sound generating unit set with multiple vibration film states. For example, different sized sound emitting cavity 300 structures and the same sized piezoelectric ceramic plates 310 may be used to change the natural frequency of the diaphragm. The structures of the sound emitting cavities 300 with different sizes can be understood as sound emitting cavities 300 with different volumes. By arranging the plurality of sound generating cavities 300 on the auxiliary sound generating layer 130, a wider frequency response range can be realized by the joint work of the plurality of sound generating cavities 300, and the sound loudness compensation can be realized by matching the sound generating cavities 300 with different sizes with the piezoelectric ceramic plates 310 corresponding to the same size.

In some embodiments, the sounding frequency band of the sounding screen 100 may be between 40Hz and 18kHz, in this range, the frequency band below 2500Hz may be regarded as a low frequency band, and above 2500Hz may be regarded as a high frequency band, limited by the sounding principle of the piezoelectric ceramic plate 310, and there may be a loudness difference between 10 dB and 20dB between sounds with different frequencies, because the sound emitted by the sounding screen 100 needs to be transmitted to the user through air, in order to ensure that the user can accurately and clearly hear the sound emitted by the sounding screen 100, the maximum value of the sounding loudness of the sounding screen 100 should be about 90dB, but because of the difference between the loudness of the high frequency band and the low frequency band, when the loudness of the sound in the high frequency band is about 90dB, the loudness of the sound in the low frequency band is only between 70dB and 80dB, so that the sounding loudness of the low frequency band is insufficient, and the sounding loudness of the low frequency band and the sound in the high frequency band may have a split sense, reducing the user experience, and therefore the sounding loudness of the high frequency band and the low frequency band needs to be maintained within the same range by loudness compensation.

In some embodiments, the loudness may be adjusted by adjusting the shape of the sounding cavity 300, for example, by testing, it is determined that the loudness of the low-frequency band sound emitted by the sounding screen is lower and the loudness of the high-frequency band sound emitted by the sounding screen is higher, where the sounding cavity 300 may include a first sounding cavity for raising the loudness of the sounding in the first frequency band and a second sounding cavity for lowering the loudness of the sounding in the second frequency band. Since the piezoelectric ceramic plate 310 resonates with the air column in the sound emitting cavity 300 to realize the overall vibration of the sound emitting screen to emit sound, the smaller the volume of the sound emitting cavity 300 is, the more the emitted sound frequency band tends to be high frequency, and the larger the volume of the sound emitting cavity 300 is, the more the emitted sound frequency band tends to be low frequency. For example, the sound emitting cavity 300 having a smaller volume may be set as the second sound emitting cavity, and the sound emitting cavity 300 having a larger volume may be set as the first sound emitting cavity.

For example, when the low-frequency sound generated by the piezoelectric ceramic plate 310 related to the low-frequency sound in the sound generating screen is insufficient, the volume of the air column in the sound generating cavity 300 may be changed by increasing the volume of the first sound generating cavity corresponding to the piezoelectric ceramic plate 310 or changing the shape of the first sound generating cavity, so as to improve the resonance effect of the piezoelectric ceramic plate 310 and the air column, and further realize the enhancement of the low-frequency sound. When the loudness of the high-frequency sound emitted by the piezoelectric ceramic plate 310 in the sound emitting screen related to the high-frequency sound is too large, the volume of the air column in the second sound emitting cavity can be changed by reducing the volume of the second sound emitting cavity corresponding to the piezoelectric ceramic plate 310 or changing the shape of the second sound emitting cavity, so that the resonance effect of the piezoelectric ceramic plate 310 and the air column is improved, and further the reduction of the loudness of the high-frequency sound is realized. By combining the volumes, the shapes and the like of the different sound emitting cavities 300, the arrangement mode can correct the loudness of the sound of all frequency bands of the sound emitting screen 100 to the same range, thereby greatly improving the sound emitting effect of the sound emitting screen.

The manner in which loudness compensation is made for projection screen sound effects is described below in terms of several possible embodiments:

Embodiment one:

fig. 8 is a schematic diagram showing a mounting structure of a piezoelectric ceramic plate and a cavity housing according to an embodiment of the present application.

In order to compensate the loudness of the low-frequency band sounding, as shown in fig. 8, the piezoelectric ceramic plate 310 is disposed on a side of the auxiliary sounding layer 130 far away from the display function layer 110, and the cavity housing 320 is covered on the piezoelectric ceramic plate 310 and encloses with the auxiliary sounding layer 130 to form the sounding cavity 300. The six cavity shells 320 and the piezoelectric ceramic plates 310 are arranged on the auxiliary sounding layer 130 to serve as sounding devices, wherein the specifications of the piezoelectric ceramic plates 310 are the same, the volumes of the six cavity shells 320 are different, the coverage area of the cavity shell 320 arranged on the upper portion of the auxiliary sounding layer 130 is the same as that of the piezoelectric ceramic plates 310, the volume of the cavity shell 320 arranged in the middle of the auxiliary sounding layer 130 is 3 times that of the cavity shell 320 arranged on the upper portion of the cavity shell 320 on the upper portion of the auxiliary sounding layer 130, and the volume of the cavity shell 320 is increased, so that the low-frequency-band response effect of the piezoelectric ceramic plates 310 is better, and the loudness of low-frequency-band sounding is improved in a targeted manner.

In this embodiment, after the loudness compensation of the low-frequency band sounding, the loudness of the low-frequency band sounding can be increased by 10-20 dB, so that the loudness of the low-frequency band sounding and the maximum value of the high-frequency band sounding are maintained at a value of about 90dB together.

It should be noted that, because the piezoelectric ceramic plate has the characteristic of large loudness of high-frequency sound, when the piezoelectric ceramic plate 310 is tested, the high-frequency sound may exceed 90dB or even 100dB when the low-frequency sound is less than 90dB, even if the volume or shape of the sound generating cavity 300 corresponding to the high-frequency sound is not adjusted. And the hearing of the user is influenced by long-time receiving of sound of about 100dB. At this time, the loudness of the high frequency band needs to be reduced to optimize the audio-visual experience of the user, for example, by adding a sound attenuation layer inside the sound emission cavity.

Embodiment two:

fig. 9 is a schematic diagram showing a mounting structure of a piezoelectric ceramic plate and a cavity housing according to another embodiment of the present application.

As shown in fig. 9, six cavity cases 320 and a piezoelectric ceramic plate 310 are provided on the projection screen as sound emitting devices, wherein the specifications of the piezoelectric ceramic plates 310 are the same, the volumes of the six cavity cases 320 are different, the coverage area of the cavity case 320 provided on the upper portion of the auxiliary sound emitting layer 130 is 1.5 times that of the piezoelectric ceramic plate 310, the volume of the cavity case 320 provided in the middle portion of the auxiliary sound emitting layer 130 is 1.5 times that of the cavity case 320 provided on the upper portion of the auxiliary sound emitting layer 130, and the volume of the cavity case 320 provided on the upper portion of the auxiliary sound emitting layer 130 is 2 times that of the cavity case 320 provided on the upper portion of the auxiliary sound emitting layer 130. By increasing the volume of the housing 320, the full band sounding loudness of the projection screen is increased.

Meanwhile, a sound-deadening wedge composed of polyurethane material is provided in the cavity housing 320 provided at the upper portion of the auxiliary sound-generating layer 130, and the sound-deadening wedge may be a quadrangular pyramid structure provided on the cavity housing 320. The height of the noise elimination wedge is half of the thickness of the cavity shell 320, and the noise elimination wedge is arranged on the inner wall of the cavity shell 320 and opposite to the piezoelectric ceramic plate 310. By providing the sound damping wedges in the cavity housing 320 with better high-band response, the sound-producing loudness of the high-band can be reduced, and the low-band sound-producing loudness and the high-band sound-producing loudness of the projection screen can be maintained in the same range. Through the noise elimination wedge that sets up in this embodiment, can make the biggest loudness restriction of high frequency channel sounding be about 90dB, avoid the emergence of the sharp and harsher scheduling problem of high frequency channel sounding.

The noise elimination layer is not limited to the noise elimination wedge, and may be noise elimination foam, noise elimination plate, rib, etc. The noise elimination wedge is not limited to the rectangular pyramid structure, and may be a triangular pyramid, a rectangular pyramid, a conical cone, or the like. According to the embodiment of the application, the projection screen in the projection display device is set to be in the structure in any one of the embodiments, the display function layer 110 is used for reflecting the light beam emitted by the projection host to display the picture, the piezoelectric ceramic plate 310 is used for exciting the sound-producing vibrating diaphragm to vibrate so as to produce the sound in a specific frequency band, and the sound-producing cavities 300 formed by different structures are mutually combined so that the sound loudness produced by the sound-producing screen 100 is better, thereby the projection screen has better sound effect, and further the perfect combination of the vision and hearing of the projection display device is realized.

It should be noted that, the foregoing different embodiments respectively illustrate the sounding principle, the sounding effect, and the like of the projection screen provided by the present application from different angles, but the embodiments are not only implemented independently. In the practical application process, the projection screen can be provided with different types and structures through combination among different embodiments, and the projection screen with different types and structures is ensured to have good sounding loudness when the sounding frequency band can be expanded, so that the sounding effect of the projection screen is integrally improved, and better audiovisual experience is brought to a user. Other ways not mentioned in the embodiments of the present application will not be described.

In addition, in the embodiment of the present application, the number and arrangement of the piezoelectric ceramic plates 310 and the cavity housing 320 are not limited.

For example, the number of the piezoelectric ceramic plates 310 and the cavity cases 320 disposed on the sound emitting screen 100 may be 4, and the 4 piezoelectric ceramic plates 310 and the cavity cases 320 are disposed in the upper left region, the lower left region, the upper right region, and the lower right region, respectively, of the backlight surface side of the sound emitting screen 100; or the number of the piezoelectric ceramic plates 310 and the cavity casing 320 provided on the sound emitting screen may be 6, and the 6 piezoelectric ceramic plates 310 and the cavity casing 320 may be provided in an upper left region, an upper middle region, an upper right region, a lower left region, a lower middle region, a lower right region, etc. on the backlight surface side of the sound emitting screen 100, respectively.

The number and method of placement of the piezoceramic wafers 310 and the chamber housing 320 are described below in terms of several possible embodiments.

Embodiment III:

Referring to fig. 4, when the piezoelectric ceramic sheet 310 is disposed in the sound emitting cavity 300, the piezoelectric ceramic sheet 310 is disposed on the auxiliary sound emitting layer 130, that is, the piezoelectric ceramic sheet 310 is directly attached to the auxiliary sound emitting layer 130. When the piezoelectric ceramic piece 310 is attached to the auxiliary sounding layer 130, the piezoelectric ceramic piece 310 is electrified to vibrate and drive the auxiliary sounding layer 130 attached to the piezoelectric ceramic piece to vibrate, and meanwhile, one side, away from the piezoelectric ceramic piece 310, of the auxiliary sounding layer 130 is connected with the display functional layer 110, so that when the auxiliary sounding layer 130 is driven by the piezoelectric ceramic piece 310 to vibrate together, the auxiliary sounding layer 130 can transmit vibration to the display functional layer 110, and the whole of the auxiliary sounding layer 130 and the display functional layer 110 can be used as a vibrating diaphragm to sound. On this basis, the direction of vibration of the piezoelectric ceramic plate 310 and the air column in the sound generating cavity 300 is away from the user for the first time, and then the vibration is reflected and changed in direction by the cavity housing 320, and meanwhile, the cavity housing 320 can also interfere sound waves, absorb noise and improve sound quality. The cavity housing 320 of different shapes and materials can absorb noise of different wavelengths to improve sound quality.

Embodiment four:

Referring to fig. 4, when the piezoelectric ceramic sheet 310 is disposed in the sound emitting cavity 300, the piezoelectric ceramic sheet 310 may be disposed on the cavity case 320, that is, the piezoelectric ceramic sheet 310 directly adheres to the sidewall of the cavity case 320 opposite to the auxiliary sound emitting layer 130. When the piezoelectric ceramic piece 310 is attached to the cavity shell 320, the piezoelectric ceramic piece 310 is powered on to vibrate and drive the cavity shell 320 attached to the piezoelectric ceramic piece to vibrate, meanwhile, since the cavity shell 320 is mounted on the auxiliary sounding layer 130, when the piezoelectric ceramic piece 310 transfers vibration to the cavity shell 320, the cavity shell 320 transfers vibration to the auxiliary sounding layer 130 again and then to the display function layer 110 connected with the auxiliary sounding layer 130, so that the whole of the display function layer 110, the auxiliary sounding layer 130 and the cavity shell 320 serves as a vibrating diaphragm to sound. On this basis, the auxiliary sounding layer 130 and the display function layer 110 are used as diaphragms to realize sounding, and meanwhile, air columns in the sounding cavity 300 vibrate under the action of the piezoelectric ceramic plates 310. The presence of the column of air is equivalent to adding load to the diaphragm of the auxiliary sound layer 130, and can act to increase loudness.

In addition, the meaning of the "structural composition" of the piezoelectric ceramic piece 310 and the sounding cavity 300 in the embodiment of the present application does not refer to the self-configuration of the piezoelectric ceramic piece 310 or the sounding cavity 300, but may also include the number, the material, the size, the arrangement manner, etc. of the piezoelectric ceramic piece 310 or the sounding cavity 300, and may even be other factors that affect the sound effect of the sounding screen due to the change of some characteristics of the piezoelectric ceramic piece 310 or the sounding cavity 300, such as the temperature and the humidity of the piezoelectric ceramic piece 310 or the sounding cavity 300, and the type of the sound propagation medium in the sounding cavity 300.

In other words, the structural composition of the piezoelectric ceramic sheet 310 and the sound emitting cavity 300 is not particularly limited in the embodiment of the present application. Illustratively, when the structural composition of the piezoelectric ceramic sheet 310 corresponds to the self-construction and the material, the piezoelectric ceramic sheet 310 may be a single-layer piezoelectric ceramic sheet, a multi-layer piezoelectric ceramic sheet, an inorganic piezoelectric ceramic sheet, an organic piezoelectric ceramic sheet, or the like; when the structure of the piezoelectric ceramic plates 310 is correspondingly arranged, the piezoelectric ceramic plates can be 2,4 or 6 … …, and when the structure of the piezoelectric ceramic plates 310 is correspondingly arranged, the piezoelectric ceramic plates 310 can be arranged in an array or in a straight shape, in an annular shape, in a random shape, etc.; when the structure of the piezoelectric ceramic plates 310 is formed into a corresponding size, the piezoelectric ceramic plates with the length, width and height of 5-60mm,5-60mm and 0.1-1mm can be adopted as the size between the piezoelectric ceramic plates 310.

The structural composition of the sound generating chamber 300 is not limited to the self-configuration of the sound generating chamber 300, and may include a shape, a number, a chamber material, a chamber size, a connection manner with the sound generating screen 100, a setting manner among the sound generating chambers 300, and the like. Illustratively, when the structural composition of the sound emitting cavity 300 corresponds to a shape, it may be circular, square, triangular, or other shape; when the structural composition of the sound emitting cavity 300 corresponds to the cavity material, the cavity can be made of an organic material or an inorganic material; when the structural composition of the sound emitting cavities 300 corresponds to the number, the sound emitting cavities may be1, 2, 4, 6, etc.; when the structural components of the sound emitting cavities 300 have corresponding sizes, the sizes among the cavities of the sound emitting cavities 300 can be all cavities with the length, width and height of 6-100mm,6-100mm and 0.2-10mm respectively; when the structural composition of the sound generating cavity 300 corresponds to the connection mode with the sound generating screen 100, the structure may be bonding (such as glue, double-sided tape, adhesive film or reworkable adhesive tape, etc.), welding, etc.; when the structural components of the sound emitting cavities 300 are correspondingly arranged, the sound emitting cavities 300 can be arranged in an array, or in a straight line, in a ring, in a random manner, or the like.

According to the projection screen provided by the embodiment of the application, the piezoelectric ceramic piece can excite the sounding vibrating diaphragm to vibrate so as to make sound, and a sounding area is formed. At this time, when a plurality of piezoelectric ceramic plates are disposed in the sound emitting screen, a plurality of different sound emitting areas are generated thereon. If the sound producing areas can be arranged according to a certain rule, the sound frequency bands generated by the sound producing areas can be expanded in general, so that the sound producing screen can produce full-frequency-band sound.

In addition, according to the embodiment of the application, the sound with the frequency of 20-20000 Hz can be divided into different frequency bands according to different intervals, namely, ultra-low frequency (200 Hz), low frequency (400 Hz), medium-low frequency (80-160 Hz), medium frequency (160-1280 Hz), medium-high frequency (1280-2560 Hz), high frequency (2560-5120 Hz) and ultra-high frequency (5120-20000 Hz).

In some embodiments, referring to fig. 3, the frame 200 may be a planar frame 200 or a curved frame 200; the frame 200 may have a ring-shaped structure or a parallel structure without side edges; or the frame 200 may be of a unitary structure or of a split structure; the material of the frame 200 may be metal or plastic, and the specific structure and material of the frame 200 are not limited in the embodiment of the present application.

In some embodiments, referring to fig. 4 and 5, the frame 200 may include an inner frame 210 and an outer frame 220, and a vertical beam 213, the inner frame 210 having a flange 211 remote from the sound emitting screen, the outer frame 220 being used to wrap the inner frame 210. Wherein, contact between flange 211 and the articulating face, the vertical beam 213 can be a plurality of, and a plurality of vertical beams 213 set up on inside casing 210, and a plurality of vertical beams 213 all are located the back of demonstration function layer 110, and a plurality of vertical beams 213 can the equidistance vertical setting to support inside casing 210, prevent inside casing 210 deformation, and then improve the intensity of frame 200.

Illustratively, the flange 211 and the vertical beam 213 may both contact the hitching surface, the sounding diaphragm, the flange 211 and the hitching surface together enclose the sounding cavity 300, and the vertical beam 213 may divide the cavity into a plurality of sounding cavities 300, and the flange 211, the vertical beam 213 and the hitching surface together form the cavity housing 320. In this embodiment, the piezoelectric ceramic plates 310 are disposed on the auxiliary sounding layer 130, and at least one piezoelectric ceramic plate 310 is disposed in each sounding cavity 300, and when the piezoelectric ceramic plates 310 are energized to vibrate, air columns in each sounding cavity 300 are driven to vibrate, so as to improve the sounding loudness of the sounding screen 100. It should be understood that in the present embodiment, the number of sound emitting cavities 300 is related to the number of vertical beams 213, for example, if the number of vertical beams 213 is one, the number of sound emitting cavities 300 is two; if there are two vertical beams 213, the number of sound emitting cavities 300 is three.

In some embodiments, the piezoelectric ceramic pieces 310 and the sound generating cavities 300 are all multiple, and the piezoelectric ceramic pieces 310 are respectively and correspondingly arranged in the sound generating cavities 300; or the piezoelectric ceramic plates 310 are multiple, the number of the sound-emitting cavities 300 is one, and the piezoelectric ceramic plates 310 are all arranged in one sound-emitting cavity 300.

For example, when there are multiple sound emitting cavities 300, the multiple piezoelectric ceramic plates 310 are respectively disposed in the multiple sound emitting cavities 300, where each piezoelectric ceramic plate 310 corresponds to one sound emitting cavity 300, and the sound emitted by the vibration of the sound emitting diaphragm excited by each piezoelectric ceramic plate 310 can achieve the enhancement of the sound loudness through the arrangement of the sound emitting cavities 300, so that the overall sound loudness is greatly expanded.

In some embodiments, the spacing between any two adjacent piezoceramic sheets 310 is equal, and the plurality of piezoceramic sheets 310 are arranged in a matrix. The mode that this kind of equipartition set up can make the sound production screen have more even sound production effect, makes the user can follow each position perception sound, and the even sound production effect of sound production screen has further been promoted to the mode that the matrix was arranged.

In addition, the structure of the sound emitting screen can be multiple, and the types of the sound emitting diaphragms also depend on the arrangement positions of the piezoelectric ceramic plates in the sound emitting screen, so that the sound emitting screen can emit different sounds due to the combination of the sound emitting screens with different structures and different types of sound emitting diaphragms.

In this embodiment, regarding the placement of the piezoelectric ceramic plates in the acoustic cavity, there may be several different embodiments as follows:

fifth embodiment:

The piezoelectric ceramic plate 310 is disposed on the auxiliary sound emitting layer 130, that is, the piezoelectric ceramic plate 310 is directly attached to the auxiliary sound emitting layer 130. When the piezoelectric ceramic piece 310 is attached to the auxiliary sounding layer 130, the piezoelectric ceramic piece 310 is electrified to vibrate and drive the auxiliary sounding layer 130 attached to the piezoelectric ceramic piece to vibrate, and meanwhile, one side, away from the piezoelectric ceramic piece 310, of the auxiliary sounding layer 130 is connected with the display functional layer 110, so that when the auxiliary sounding layer 130 is driven by the piezoelectric ceramic piece 310 to vibrate together, the auxiliary sounding layer 130 can transmit vibration to the display functional layer 110, and the whole of the auxiliary sounding layer 130 and the display functional layer 110 can be used as a vibrating diaphragm to sound. On this basis, the vibration direction of the piezoelectric ceramic piece 310 and the air column in the sound generating cavity is the direction away from the user for the first time, and then the vibration direction is reflected and changed through the cavity shell 320, meanwhile, the cavity shell 320 can also interfere sound waves, absorb noise and improve sound quality. The cavity housing 320 of different shapes and materials can absorb noise of different wavelengths to improve sound quality.

Example six:

The piezoelectric ceramic plate 310 is disposed on the cavity casing 320, that is, the piezoelectric ceramic plate 310 is directly attached to a side wall of the cavity casing 320 opposite to the auxiliary sound emitting layer 130. When the piezoelectric ceramic piece 310 is attached to the cavity shell 320, the piezoelectric ceramic piece 310 is powered on to vibrate and drive the cavity shell 320 attached to the piezoelectric ceramic piece to vibrate, meanwhile, since the cavity shell 320 is mounted on the auxiliary sounding layer 130, when the piezoelectric ceramic piece 310 transfers vibration to the cavity shell 320, the cavity shell 320 transfers vibration to the auxiliary sounding layer 130 again and then to the display function layer 110 connected with the auxiliary sounding layer 130, so that the whole of the display function layer 110, the auxiliary sounding layer 130 and the cavity shell 320 serves as a vibrating diaphragm to sound. On this basis, the auxiliary sounding layer 130 and the display function layer 110 are used as diaphragms to realize sounding, and air columns in the sounding cavity vibrate under the action of the piezoelectric ceramic plates 310. The presence of the air column is equivalent to adding load to the diaphragm of the auxiliary sounding layer 130, and can play a role in improving sound intensity.

Example three

The piezoelectric ceramic plates 310 are disposed between the auxiliary sounding layer 130 and the cavity housing 320, and the piezoelectric ceramic plates 310 are respectively connected with the cavity housing 320 through corresponding connection structures. When the piezoelectric ceramic piece 310 vibrates, the piezoelectric ceramic piece can drive the cavity shell 320 to vibrate through the connecting structure, and the vibration of the cavity shell 320 is transmitted to the auxiliary sounding layer 130, meanwhile, one side, away from the piezoelectric ceramic piece 310, of the auxiliary sounding layer 130 is connected with the display function layer 110, so that when the auxiliary sounding layer 130 is driven by the piezoelectric ceramic piece 310 to vibrate, the auxiliary sounding layer 130 can transmit the vibration to the display function layer 110, and the whole of the auxiliary sounding layer 130 and the display function layer 110 serves as a vibrating diaphragm to sound.

It should be noted that, the setting position of the piezoelectric ceramic piece 310 can be adaptively adjusted according to the material of the cavity housing 320, the parameters of the sound emitting screen, and the sound emitting requirement.

In some possible embodiments, the cavity housing 320 and the auxiliary sounding layer 130 may be connected by a double-sided adhesive tape, a screw connection, a magnetic attachment, or the like. The connection mode between the cavity shell 320 and the auxiliary sounding layer 130 can be adaptively adjusted according to the material, parameters and the material of the cavity shell 320 of the actual auxiliary sounding layer 130, so long as the sounding requirement is satisfied under the premise of ensuring the connection strength. In some embodiments, the thickness of the cavity housing 320 is less than 1mm in order to enable resonance sounding of the cavity housing 320.

In some possible embodiments, the material of the housing 320 may be selected from a thin layer of metal, plastic, kraft paper, etc. When the thin metal is used as the cavity shell 320, the metal shell is favorable for prolonging the service life of the cavity shell 320, and meanwhile, the metal selectivity is wider, and corresponding metal materials can be selected according to different sounding requirements, for example, metals with relatively higher stability, such as copper, can be selected. When the thin metal is selected as the cavity shell 320, the thin metal can be correspondingly connected with the auxiliary sounding layer 130 by adopting a screw connection or magnetic attraction bonding mode.

When the plastic is adopted as the cavity shell 320, the plastic shell is favorable for ensuring the shape of the shell, and plastic materials with higher transparency, such as a sub-power material, can be adopted, and when the plastic with higher transparency is adopted as the cavity shell 320, quality inspection and after-sales maintenance are facilitated, and staff can observe and maintain the piezoelectric ceramic plate 310 arranged in the sound generating cavity through the plastic shell intuitively. When the plastic material is the cavity shell 320, the auxiliary sound layer 130 can be correspondingly connected with the cavity shell by adopting a double-sided adhesive tape bonding or screw connection mode.

When kraft paper is used as the cavity shell 320, the kraft paper is light due to dead weight, so that a resonance effect is easy to form, the whole weight of the sounding screen can be well reduced, and the market competitiveness of the product is improved. Meanwhile, kraft paper has the advantages of stable heat transfer performance, no fluctuation and moderate heat transfer rate. When kraft paper is used as the cavity casing 320, the kraft paper can be correspondingly connected with the auxiliary sounding layer 130 by adopting a double-sided bonding connection mode.

In the projection screen provided by the embodiment of the application, when the auxiliary sounding layer is included in the sounding screen, in order to ensure the flatness of the auxiliary sounding layer, as shown in fig. 6, the sounding screen may further include a plurality of elastic connectors 400, and the elastic connectors 400 may include, but are not limited to, elastic belts or springs. Each elastic connection 400 has opposite first and second ends (see a in fig. 6) and b in fig. 6), the first end of each elastic connection 400 is connected to the edge of the auxiliary sound emitting layer 130, and the second end of each elastic connection 400 is connected to the inner frame 210.

Wherein, a plurality of elastic connection pieces 400 all are in tensile state, apply outside power to the edge of supplementary sound production layer 130 to make the sound production vibrating diaphragm that contains supplementary sound production layer 130 flatten, the vibration amplitude of sound production vibrating diaphragm under the effect of piezoceramics piece under the flattening state is more controllable, thereby has improved projection screen's sound production effect, and the display screen that the sound production vibrating diaphragm of flattening can be better.

Referring to fig. 7, when the auxiliary sounding layer 130 is disposed, the edge of the auxiliary sounding layer 130 may extend beyond the edge of the display function layer, and a plurality of connection holes 132 are disposed in the edge of the auxiliary sounding layer 130 extending outside the display function layer. Each of the connection holes 132 may be a circular hole, the plurality of connection holes 132 surround the auxiliary sounding layer 130, the plurality of connection holes 132 are in one-to-one correspondence with the plurality of elastic connection members 400, and the first end of each elastic connection member 400 is connected with the peripheral wall of the corresponding connection hole 132.

In some examples, the first end of the elastic connection member 400 may be disposed through the connection hole 132 and connected with the inner wall of the connection hole 132, thereby being stably connected with the auxiliary sound layer 130.

In other examples, the auxiliary sounding layer 130 is further provided with a plurality of connecting pieces 133, the connecting pieces 133 may be circular rings or eyelet buttons (eyelet buttons are also known as eyelets and shoes, and are shaped into circles, and large-area holes are formed in the middle of the eyelet buttons to play a role of ventilation or rope threading), the plurality of connecting pieces 133 are in one-to-one correspondence with the plurality of connecting holes 132, the outer ring of each connecting piece 133 is connected with the edge of the corresponding connecting hole 132, or a part of the connecting piece 133 wraps the edge of the corresponding connecting hole 132, the first end of each elastic connecting piece 400 is connected with the corresponding connecting piece 133, for example, referring to fig. 6, the first end (a end) of each elastic connecting piece 400 is an annular buckle or an integral connecting ring 212, and the annular buckle is buckled with the connecting piece 133, so that the elastic connecting piece 400 is connected with the auxiliary sounding layer 130, thereby avoiding that the tensile force of the elastic connecting piece 400 directly acts on the connecting hole 132, avoiding the tearing damage of the edge of the connecting hole 132, further protecting the auxiliary sounding layer 130, ensuring the sounding effect of the diaphragm, and prolonging the service life of the auxiliary sounding layer 130.

Of course, in other examples, the first end of the elastic connection member 400 may be fixed on the surface of the edge area of the auxiliary sound generating layer 130 by bonding or the like, so as to simplify the connection structure, improve the assembly efficiency of the projection screen, and reduce the weight of the projection screen.

In addition, the second end of each elastic connection member 400 may be connected to the inner frame 210, the outer frame 220 and the inner frame 210 may be square frames 200, and the cross sections of the outer frame 220 and the inner frame 210 may be two opposite L-shapes, so that the outer frame 220 and the inner frame 210 may be surrounded by an annular groove having a certain width and depth, the width of the annular groove should be greater than that of the elastic connection member 400, and the length of the annular groove should be greater than that of the elastic connection member 400, thereby hiding the elastic connection member 400 and improving the aesthetic property of the projection screen according to the embodiment of the present application.

In the specific connection, as shown in fig. 6, a plurality of connection rings 212 may be disposed on the inner frame 210, the plurality of connection rings 212 are in one-to-one correspondence with the plurality of elastic connection members 400, and the second end of each elastic connection member 400 is connected with the corresponding connection ring 212, so that the second end of the elastic connection member 400 is conveniently fixed on the inner frame 210, and further, the assembly of the projection screen according to the embodiment of the present application is convenient.

The connecting ring 212 has a certain rigidity, is not easy to deform, and is a metal ring, but is not limited to metal.

Of course, in other examples, the second end of each elastic connection member 400 may be fixed to the surface of the inner frame 210 by bonding or the like, so as to simplify the connection structure, improve the assembly efficiency of the projection screen, and reduce the weight of the projection screen.

In some embodiments, for frames having flanges, the frame may further include a shock absorbing layer (not shown) disposed at the connection of the flange to the external wall for cushioning the projection screen. The damping layer can be any one of foam, elastic rubber, silica gel and latex, and the specific structure and the material of the damping layer are not limited.

It should be further noted that, the numerical values and the numerical ranges related to the embodiments of the present application are approximate values, and may have a certain range of errors under the influence of the manufacturing process, and those errors may be considered to be negligible by those skilled in the art.

It is to be understood that, based on the several embodiments provided in the present application, those skilled in the art may combine, split, reorganize, etc. the embodiments of the present application to obtain other embodiments, which all do not exceed the protection scope of the present application.

The foregoing detailed description of the embodiments of the present application further illustrates the purposes, technical solutions and advantageous effects of the embodiments of the present application, and it should be understood that the foregoing is merely a specific implementation of the embodiments of the present application, and is not intended to limit the scope of the embodiments of the present application, and any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the embodiments of the present application should be included in the scope of the embodiments of the present application.

Claims

1. A projection screen, comprising:

The sound generating screen comprises a sound generating vibrating diaphragm; a plurality of sound generating cavities are arranged on one side of the sound generating vibrating diaphragm;

The frame is connected with the periphery of the sound generating screen;

The piezoelectric ceramic piece is arranged in the sounding cavity; the size, the material and the volume ratio of the sounding cavities are all or partially different, the volume ratio is the ratio of the volume of the piezoelectric ceramic piece to the volume of the sounding cavity, and the loudness influence of the sounding cavities on sound waves in different frequency bands is different.

2. The projection screen of claim 1 wherein the sound emitting diaphragm comprises a display function layer, an adhesive layer, and a flexible auxiliary sound emitting layer;

The display function layer and the auxiliary sounding layer are attached to form a composite vibrating diaphragm structure through the adhesive layer, and the sounding cavity is arranged on one side, away from the display function layer, of the auxiliary sounding layer.

3. The projection screen of claim 1 wherein the sound emitting cavities of different sizes differ in volume and/or the sound emitting cavities of different sizes differ in shape.

4. The projection screen of claim 3 wherein the sound producing cavities comprise a first sound producing cavity for increasing the sound producing loudness of a first frequency band and a second sound producing cavity for decreasing the sound producing loudness of a second frequency band, the first sound producing cavity and the second sound producing cavity being different in volume and/or shape, and a sound damping layer being provided in the second sound producing cavity.

5. The projection screen of claim 4 wherein the sound attenuating layer comprises sound attenuating foam and/or sound attenuating wedges.

6. The projection screen of claim 1 wherein the piezoelectric ceramic sheet comprises a vibration plate and a layer of piezoelectric ceramic material disposed on the vibration plate;

The piezoelectric ceramic material layer is provided with an anode pin and a cathode pin; the positive electrode pin and the negative electrode pin are connected with a host signal output end;

The electric signal frequencies accessed by the piezoelectric ceramic plates in different sounding cavities are all or partially different.

7. The projection screen of claim 1 wherein the piezoelectric ceramic sheet is disposed on the sound-emitting diaphragm; or the piezoelectric ceramic piece is arranged at one side of the sounding cavity, which is far away from the sounding vibrating diaphragm; or the piezoelectric ceramic piece is arranged in the middle of the sound-emitting cavity.

8. The projection screen of claim 1 wherein the frame comprises:

An inner frame;

the outer frame is used for wrapping the inner frame;

the sound-producing vibrating diaphragm comprises a plurality of elastic connecting pieces, wherein each elastic connecting piece is provided with a first end and a second end which are opposite, the first end of each elastic connecting piece is connected with the edge of the sound-producing vibrating diaphragm, the second end of each elastic connecting piece is connected with the inner frame, and the elastic connecting pieces are used for flattening the sound-producing vibrating diaphragm through tension.

9. The projection screen of claim 8 wherein the inner frame is provided with a flange distal from the sound emitting screen;

The flange is attached to the hanging surface, so that the hanging surface and the sounding vibrating diaphragm are enclosed to form the sounding cavity.

10. A projection display device comprising a laser projector and a projection screen as claimed in any one of claims 1 to 9;

The laser projector is in communication connection with the projection screen.