CN219718068U

CN219718068U - Screen vibrator

Info

Publication number: CN219718068U
Application number: CN202320741668.6U
Authority: CN
Inventors: 李艳龙
Original assignee: Shenzhen Timewaying Technology Co ltd
Current assignee: Shenzhen Timewaying Technology Co ltd
Priority date: 2022-11-11
Filing date: 2023-04-06
Publication date: 2023-09-19
Anticipated expiration: 2033-04-06

Abstract

The utility model is suitable for the technical field of laser projection display, and provides a screen vibrator which is used for being attached to the back of a screen to eliminate speckles of a laser projection picture. The screen vibrator includes: the device comprises a fixed part with an excitation coil, a vibrator comprising two magnets and an elastic connecting part comprising two elastic pieces. When the vibrator provided by the utility model is attached to the back of a screen, an electromagnetic field can be generated when the exciting coil in the vibrator is driven, and the two magnets can respectively utilize the electromagnetic fields at two sides of the exciting coil to generate magnetic force with the same direction so as to push the vibrator to vibrate. The vibrator is supported by the two elastic pieces, so that the problem of uneven stress on two sides of a single elastic piece is solved, and compared with the scheme that the single elastic piece is matched with a single magnet, the screen vibrator provided by the utility model has the advantages of more stable vibration, high vibration intensity and higher electric energy utilization rate.

Description

Screen vibrator

Technical Field

The utility model belongs to the technical field of laser projection display, and particularly relates to a screen vibrator.

Background

Laser sources have been widely used in the projection display industry, but because of the strong monochromaticity of laser, laser projection generally has serious speckles, and it is a common practice in industry to eliminate the speckles by vibrating a screen. The existing vibrator has various technical routes, and mainly comprises a low-frequency sound box vibration technology, a hollow cup direct current eccentric vibration motor, a brushless motor, a linear vibrator and the like.

There are currently electromagnetic vibrators in which a magnet and a weight are provided on both sides of a spring, and a movable end of the spring is connected to the magnet, the movable end serving as a sole fulcrum for supporting the magnet and the weight. In actual use, the vibrator is attached to the back of the screen, and the vibration direction of the vibrator is perpendicular to the surface of the screen and generally parallel to the horizontal plane.

In order to match the proper vibration frequency, the mass of the balancing weight needs to be adjusted. When the springs are vertically placed, if the weights of structural members at two sides of the springs are inconsistent, due to gravity, a stress component in a downward direction exists at the heavier side, and the vibration direction cannot be kept perpendicular to the screen surface, but a vibration component in a vertical direction along the gravity exists. When the amplitude is large, the magnet may touch the coil, and the coil is damaged, so that the problem of stress balance of the vibrator needs to be solved. In addition, as the vibrator only uses one spring, the elasticity is small, and the vibration amplitude of the vibrator is obviously influenced by the screen tightness. For the magnetic field generated by the coil, the magnet is arranged on one side of the coil, so that the magnetic field on one side of the coil is utilized, and the energy utilization rate is low.

Disclosure of Invention

The utility model aims to solve the technical problem of maintaining the vibration direction of the screen vibrator stable and improving the energy utilization rate.

In order to solve the above technical problems, the present utility model provides a screen vibrator, which is used for being attached to the back of a screen, and includes:

the fixed part comprises a hollow shell and an excitation coil fixedly arranged in the hollow shell, the excitation coil can generate an electromagnetic field when being driven, and the excitation coil is provided with a first side and a second side which are opposite;

a vibrator including a first magnet for vibrating by inducing a magnetic field from a first side of the exciting coil, a second magnet for vibrating by inducing a magnetic field from a second side of the exciting coil, and a connection block for rigidly connecting the first magnet and the second magnet; the polarities of the two ends of the first magnet which are relatively adjacent to the second magnet are the same;

the elastic connecting part comprises a first elastic piece and a second elastic piece; the first elastic piece is connected between the first magnet and the inner wall of the hollow shell and is used for transmitting vibration waves to the screen through the hollow shell along with the vibration of the first magnet; the second elastic piece is connected between the second magnet and the inner wall of the hollow shell and is used for transmitting vibration waves to the screen through the hollow shell along with the vibration of the second magnet.

Further, the connection block has opposite first and second end faces; the first magnetic pole end of the first magnet is fixedly connected to the first end face, and the first magnetic pole end of the second magnet is fixedly connected to the second end face; the moving end of the first elastic piece is connected with the second magnetic pole end of the first magnet, and the fixed end of the first elastic piece is connected to the inner wall of the hollow shell; the moving end of the second elastic piece is connected with the second magnetic pole end of the second magnet, and the fixed end of the second elastic piece is connected to the inner wall of the hollow shell; wherein the first pole end of the first magnet has the same polarity as the first pole end of the second magnet, and the second pole end of the first magnet has the same polarity as the second pole end of the second magnet.

Further, the vibrator is separated from and coaxial with the exciting coil.

Further, the connection block is located in the exciting coil, the first magnet is located on a first side of the exciting coil, and the second magnet is located on a second side of the exciting coil.

Further, the overall length of the vibrator is greater than the axial thickness of the exciting coil.

Further, the first elastic member and the second elastic member are both springs.

Further, the hollow shell is in a shape of a side surface closed and two bottom surface openings, a first opening and a second opening are formed, and a plurality of fixing holes are formed in the edges of the first opening and the second opening; the spring is a flat spring and is provided with a moving end positioned at the center and a plurality of fixed ends positioned at the periphery; the first elastic piece is fixed on the first opening, the moving end is connected with the second magnetic pole end of the first magnet, and the fixed ends are fixed in the fixed holes of the first opening through the fixing piece; the second elastic piece is fixed on the second opening, the moving end is connected with the second magnetic pole end of the second magnet, and the fixed ends are fixed in the fixed holes of the second opening through the fixing piece.

Further, the screen vibrator further comprises a balancing weight, wherein the balancing weight comprises an internal balancing weight, and the internal balancing weight is the connecting block.

Further, the balancing weight further comprises an external balancing weight, the external balancing weight is located on the outer side of the hollow shell and connected with the movable end of the first elastic piece or the movable end of the second elastic piece, and the balancing weight, the first magnet and the second magnet are located on the same central axis.

When the vibrator provided by the utility model is attached to the back of a screen, speckles of a laser projection picture can be eliminated, an electromagnetic field can be generated when an exciting coil in the vibrator is driven, and two magnets can respectively utilize the electromagnetic fields at two sides of the exciting coil to generate magnetic force with the same direction so as to push the vibrator to vibrate. The vibrator is supported by the two elastic pieces, so that the problem of uneven stress on two sides of a single elastic piece is solved, and compared with the scheme that the single elastic piece is matched with a single magnet, the screen vibrator provided by the utility model has the advantages of more stable vibration, high vibration intensity and higher electric energy utilization rate.

Drawings

FIG. 1 is a schematic view of a vibrator of a single spring single magnet construction;

FIG. 2 is an overall block diagram of a screen vibrator according to an embodiment of the present utility model;

fig. 3 is a positional relationship diagram between the hollow housing and the excitation coil in the fixing portion provided by the embodiment of the utility model;

fig. 4 is a block diagram of an exciting coil according to an embodiment of the present utility model.

Fig. 5 is a mounting structure diagram of a vibrator and an elastic connection portion provided in an embodiment of the present utility model;

fig. 6 is a structural view after the exciting coil is mounted on the basis of fig. 5;

FIG. 7 is a diagram showing a structure of a vibrator according to an embodiment of the present utility model;

FIG. 8 is a cross-sectional view of a screen vibrator according to the present utility model;

fig. 9 and 10 are waveform diagrams of driving signals in the form of ac sine waves and ac square waves, respectively, provided in an embodiment of the present utility model;

FIG. 11 is a graph showing the magnetic field strength profile of a coil in axial section under constant current conditions provided by an embodiment of the present utility model;

FIGS. 12A and 12B are two exemplary positional relationships of a magnet relative to an excitation coil, respectively, provided by embodiments of the present utility model;

FIG. 13 is a graph of force magnitude versus position for a magnet placed inside an excitation coil with constant current;

FIGS. 14A and 14B are schematic diagrams illustrating force analysis of the screen vibrator according to the present utility model when current is driven in different directions;

fig. 15A and 15B are respectively the relative positional relationship of the magnetic poles of two magnets provided in the embodiment of the present utility model.

Detailed Description

The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

After the vibrator is attached to the back of the screen, as shown in fig. 1, the magnet 1a and the balancing weight 1b are respectively installed on the left and right sides of the elastic member 1c (such as a spring), the magnet 1a is located in the coil 1d, and since the overall natural frequency of the vibrator depends on the vibrator mass, the spring elastic coefficient and the shell mass, the weight moment of the magnet 1a and the balancing weight 1b on the left and right sides of the elastic member 1c relative to the center position of the elastic member 1c is equal, and the vibrator mass, the elastic coefficient of the elastic member 1c and the shell mass are matched, so that it is difficult to achieve comprehensive consideration in practical design, and the performance of the vibrator is inconsistent due to deviation of the elastic force of the produced elastic member. In the vibration, the vibrator does not vibrate in the screen normal direction due to the unequal gravity moments, but vibrates in a plane defined by the screen normal and the gravity direction, and has a vibration component in the gravity direction, which is undesirable.

Therefore, the utility model provides a scheme for solving the problems, and the moving part of the vibrator is fixed by adopting two elastic pieces, so that the moving part is supported by at least two supporting points, and the problem of unbalanced stress can be effectively solved.

Based on the above principle, referring to fig. 2 to 8, the screen vibrator provided by the present utility model may be applied to the back of a screen, and includes a fixing portion 1, a vibrator 2, and an elastic connection portion 3, where the vibrator 2 includes two magnets, and the elastic connection portion 3 includes two elastic members.

The fixed part 1 comprises a hollow housing 11 and an exciting coil 12 fixed inside the hollow housing 11, the exciting coil 12 can generate an electromagnetic field when driven, and the exciting coil 12 has a first side 12a and a second side 12b opposite to each other.

The exciting coil 12 is fixedly connected with the hollow shell 11, and can be fixed by using an adhesive.

The exciting coil 12 is electrically connected to a driving circuit through a driving terminal 121 and a driving terminal 122, and the driving circuit is configured to output a driving signal to the exciting coil 12, where the driving signal may be an ac sine wave as shown in fig. 9, an ac square wave as shown in fig. 10, an ac triangle wave, an ac sawtooth wave, or the like.

As another implementation, the driving signal may also be a dc wave, such as a half sine wave, a square wave, a triangle wave, etc.

When the exciting coil 12 is driven by using a dc waveform, the direction of the current is not changed all the time, so that the direction of the magnetic force of the electromagnetic field generated by the exciting coil 12 is not changed, the elastic force of the elastic member itself is required for rebound of the vibrator 2, and no current flows through the exciting coil 12 in the rebound stage of the vibrator 2. When the exciting coil 12 is driven by an ac waveform, the direction of the magnetic force generated by the exciting coil 12 is periodically changed due to the periodic change of the current direction, and the rebound of the vibrator 2 is also subjected to the magnetic force generated by the exciting coil 12 in addition to the elastic force of the elastic member itself, and the direction is identical to the rebound direction of the elastic member, so that both the acceleration and the vibration amplitude are superior to those of the driving of the dc waveform.

The vibrator 2 includes a first magnet 21 for inducing a magnetic field from a first side 12a of the exciting coil 12 to vibrate, a second magnet 22 for inducing a magnetic field from a second side 12b of the exciting coil 12 to vibrate, and a connection block 23 for rigidly connecting the first magnet 21 and the second magnet 22.

The term "rigidly connected" means that the first magnet 21 and the second magnet 22 are connected via the connection block 23, and that the relative positions of the first magnet 21 and the second magnet 22 do not change during vibration.

As shown in fig. 8, the first magnet 21 and the second magnet 22 are connected by a connection block 23, and then are placed on the central axis of the exciting coil 12, and the first magnet 21 and the second magnet 22 protrude from the exciting coil 12.

For an excitation coil having a constant current, the distribution of magnetic field strength in its surrounding space is as shown in fig. 11, where the magnetic field strength is maximum, at a position centered inside the excitation coil. However, the position with the greatest force is not the position with the greatest magnetic field for the permanent magnet placed inside the excitation coil. Fig. 12A and 12B are two exemplary positions of the magnet relative to the excitation coil, the two positions being at the edge of the excitation coil and at the center of the excitation coil, respectively. The maximum force is found by force test of the magnet in the exciting coil at the edge of the exciting coil, and the force is zero when the magnet is located at the center of the coil, as shown in fig. 13. Therefore, according to the force magnitude versus position curve of fig. 13, the present utility model proposes a scheme of adding one magnet on the other side of the exciting coil, i.e. using two magnets, for fully utilizing the magnetic field on the other side of the coil.

The first magnet 21 and the second magnet 22 are respectively located on the central axis of the exciting coil 12 near the edges of both sides of the exciting coil 12, and are fixed using a connection block 23. The first magnet 21 and the second magnet 22 are integrated after fixing, no relative position change occurs, and the polarities of the two ends of the first magnet 21 and the second magnet 22 which are relatively adjacent are the same, in this embodiment, "two ends which are relatively adjacent" means that the ends of the first magnet 21 which are in contact with the connection block 23 are in relatively adjacent relationship with the ends of the second magnet 22 which are in contact with the connection block 23, and the ends of the first magnet 21 which are far away from the connection block 23 are in relatively distant relationship with the ends of the second magnet 22 which are far away from the connection block 23.

When the exciting coil 12 is energized, it is equivalent to a magnet. When the exciting coil 12 is equivalent to a magnet having an upper end of N pole and a lower end of S pole as shown in fig. 14A, the S pole of the first magnet 21 located above the exciting coil 12 is downward, and is attracted by the exciting coil 12; the second magnet 22 located below the exciting coil 12 has its S pole facing upward and receives the repulsive force of the exciting coil 12, so that the vibrator composed of the two magnets and the connection block 23 receives a resultant downward force. When the exciting coil 12 has a magnet with an equivalent upper end of S pole and a lower end of N pole, as shown in fig. 14B, the S pole of the first magnet 21 located above the exciting coil 12 is downward, and is subjected to repulsive force of the exciting coil 12; the second magnet 22 located below the exciting coil 12 has its S pole facing upward and receives the attractive force of the exciting coil 12, so that the vibrator composed of the two magnets and the connection block 23 receives an upward resultant force.

For the fixed first magnet 21 and the fixed second magnet 22, the magnetic poles at adjacent ends are the same, and may be S-poles or N-poles at the same time, as shown in fig. 15A and 15B.

The elastic connection part 3 comprises a first elastic piece 31 and a second elastic piece 32; the first elastic member 31 is connected between the first magnet 21 and the inner wall of the hollow housing 11 for transmitting vibration waves to the screen through the hollow housing 11 as the first magnet 21 vibrates; the second elastic member 32 is connected between the second magnet 22 and the inner wall of the hollow housing 11 for transmitting vibration waves to the screen through the hollow housing 11 as the second magnet 22 vibrates.

The first elastic member 31 and the second elastic member 32 may be springs, such as a spiral tower-shaped spring, a flat plate-shaped spring, etc., and are illustrated in the drawings.

The specific positional relationship between the first and second magnets 21, 22 and the connection block 23 is not limited, and for example, two magnets may be embedded inside the connection block 23 or may be fixed to both end faces of the connection block 23 as shown in fig. 5 to 8.

Referring to fig. 5-8, the connection block 23 has opposite first and second end faces 231, 232. The first pole end 2a of the first magnet 21 is fixedly connected to the first end surface 231, and the first pole end 2a of the second magnet 22 is fixedly connected to the second end surface 232; the moving end of the first elastic member 31 is connected with the second pole end 2b of the first magnet 21, and the fixed end of the first elastic member 31 is connected to the inner wall of the hollow housing 11; the moving end of the second elastic member 32 is connected to the second magnetic pole end 2b of the second magnet 22, and the fixed end of the second elastic member 32 is connected to the inner wall of the hollow housing 11. After the fixing, the fixing ends of the two elastic pieces, the hollow shell 11 and the exciting coil 12 do not change relative positions.

The vibrator 2 is separated from the exciting coil 12 as a whole and coaxial with the exciting coil. Specifically, the connection block 23 is located in the exciting coil 12, the first magnet 21 is located on the first side 12a of the exciting coil 12, and the second magnet 22 is located on the second side 12b of the exciting coil 12.

The overall length of the vibrator 2 is greater than the axial thickness of the excitation coil 12.

As an implementation manner, as shown in fig. 3, the hollow shell 11 is in a shape of a side surface closed and two bottom surfaces open to form a first opening and a second opening, and the edges of the first opening and the second opening are provided with a plurality of fixing holes 111, when two elastic pieces are flat springs, the first elastic piece 31 is fixed on the first opening, the moving end a is connected with the second magnetic pole end 2B of the first magnet 21, and a plurality of fixing ends B are fixed in the fixing holes 111 of the first opening through fixing pieces; the second elastic member 31 is fixed on the second opening, and the moving end a is connected with the second magnetic pole end 2B of the second magnet 22, and the fixed ends B are fixed in the fixed holes 111 of the second opening through the fixing members. Wherein, the mounting can be realized with the screw. The motion end A is positioned at the center of the flat spring, and the fixed ends B are positioned at the periphery of the flat spring.

The whole body formed by the first magnet 21, the second magnet 22 and the connecting block 23, i.e. all the components fixed on the movable end of the spring, can be regarded as a vibrator part of the vibrator, and the integral natural frequency of the vibrator depends on the elastic coefficient of the spring and the mass of the vibrator, so that the vibrator cannot have too small mass in order to provide certain vibration intensity for the vibrator, in this embodiment, the connecting block 23 is used as a built-in balancing weight of the screen vibrator, and therefore, the ideal vibration intensity can be achieved by selecting a connecting block 23 with proper mass.

In practical vibrator designs, if the requirement cannot be met by only using an internal balancing weight, an external balancing weight can be added, as shown in fig. 2, the external balancing weight 4 is located outside the hollow shell 11 and connected with the movable end a of the first elastic member 31 or the second elastic member 31, and is located on the same central axis as the first magnet 21 and the second magnet 22.

In addition, the frequency of the driving signal applied to the exciting coil 12 is set near the natural frequency of the vibrator to ensure the maximization of the energy utilization rate, while not completely generating resonance to cause the vibrator to be damaged. In addition, the natural frequency of the vibrator is adjusted to be between 5 and 200Hz, and the lower the frequency is, the less sensitive the human ear is, so that the influence of the noise of the vibrator on the sound box of the movie hall is greatly reduced while the speckle of the laser projection picture is eliminated.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims

1. A screen vibrator for attachment to a rear surface of a screen, comprising:

2. The screen vibrator according to claim 1, wherein the connection block has opposite first and second end faces;

the first magnetic pole end of the first magnet is fixedly connected to the first end face, and the first magnetic pole end of the second magnet is fixedly connected to the second end face;

the moving end of the first elastic piece is connected with the second magnetic pole end of the first magnet, and the fixed end of the first elastic piece is connected to the inner wall of the hollow shell;

the moving end of the second elastic piece is connected with the second magnetic pole end of the second magnet, and the fixed end of the second elastic piece is connected to the inner wall of the hollow shell;

wherein the first pole end of the first magnet has the same polarity as the first pole end of the second magnet, and the second pole end of the first magnet has the same polarity as the second pole end of the second magnet.

3. The screen vibrator of claim 1 wherein the vibrator is separate and coaxial from the excitation coil.

4. The screen vibrator of claim 3 wherein the connection block is positioned within the exciter coil, the first magnet is positioned on a first side of the exciter coil, and the second magnet is positioned on a second side of the exciter coil.

5. The screen vibrator of claim 1 wherein the vibrator has an overall length greater than an axial thickness of the excitation coil.

6. The screen vibrator according to claim 1, wherein the first elastic member and the second elastic member are springs.

7. The screen vibrator according to claim 6, wherein the hollow housing has a shape of a side surface closed, two bottom surface openings forming a first opening and a second opening, and edges of the first opening and the second opening are provided with a plurality of fixing holes;

the spring is a flat spring and is provided with a moving end positioned at the center and a plurality of fixed ends positioned at the periphery;

the first elastic piece is fixed on the first opening, the moving end is connected with the second magnetic pole end of the first magnet, and the fixed ends are fixed in the fixed holes of the first opening through the fixing piece;

the second elastic piece is fixed on the second opening, the moving end is connected with the second magnetic pole end of the second magnet, and the fixed ends are fixed in the fixed holes of the second opening through the fixing piece.

8. The screen vibrator according to claim 1, further comprising a weight including a built-in weight, the built-in weight being the connection block.

9. The screen vibrator of claim 8, wherein the weight further comprises an external weight located outside the hollow housing and connected to the movable end of the first elastic member or the second elastic member, and the weight is located on the same central axis as the first magnet and the second magnet.