Scanning actuator and scanning display module

Abstract

The utility model discloses a scanning actuator and a scanning display module. The scanning actuator comprises a base, a fast axis actuating part, an adapter and a slow axis actuating part which are sequentially arranged from back to front. The adapter is connected with the base through a middle beam; the rear end of the slow shaft actuating part is connected with the adapter; the fast axis actuating part comprises a first piezoelectric actuating part and a second piezoelectric actuating part which are arranged on the two sides of the middle beam. The first piezoelectric actuating part and the second piezoelectric actuating part can synchronously and reversely stretch out and draw back in the front-back direction. And the first piezoelectric actuating part and the second piezoelectric actuating part are respectively hinged with the adapter. When the scanning actuator vibrates, force in the front-back direction can be transmitted between the fast axis actuating part and the slow axis actuating part in a hinged mode, transmission of torsional force is limited, and therefore the coupling problem between the fast axis and the slow axis is relieved, the phenomenon that odd-row vertical lines and even-row vertical lines of a scanning track are split is avoided, and the projection display quality is improved.

Description

Technical Field

[0001] The utility model relates to the field of projection display, and in particular to a scanning actuator and a scanning display module. Background Art

[0002] The imaging principle of fiber scanning display (FSD) technology is to use an actuator to drive an optical fiber to move along a predetermined two-dimensional scanning trajectory, and modulate the light source to output light corresponding to each pixel of the image to be displayed. Then, the light corresponding to each pixel of the image to be displayed is projected one by one through the optical fiber onto the projection surface to form a projected image.

[0003] A grid-type FSD scanner generally refers to a device that realizes projection display through grid-type scanning. Generally speaking, the fast axis of a grid-type FSD scanner is directly connected to the slow axis. Regardless of whether the fast axis is located at the tail, end, or integral with the slow axis, it is difficult to avoid the influence of the reaction force generated by the large-amplitude vibration of the slow axis on the vibration characteristics of the fast axis, thereby leading to the coupling problem of the fast and slow axes. When displaying a grid image, the odd and even vertical lines of the scanning trajectory will have a fork problem. Utility Model Content

[0004] The purpose of the utility model is to provide a scanning actuator and a scanning display module for alleviating the influence of the reaction force generated by the large-amplitude vibration of the slow axis of the grid-type FSD scanner in the prior art on the fast axis vibration characteristics, resulting in the fast-slow axis coupling problem.

[0005] In order to achieve the above-mentioned purpose of the utility model, the first aspect of the embodiment of the utility model provides a scanning actuator, including a base, a fast-axis actuator, an adapter and a slow-axis actuator arranged in sequence from the back to the front; the adapter is connected to the base through an intermediate beam; the rear end of the slow-axis actuator is connected to the adapter; the fast-axis actuator includes a first piezoelectric actuator and a second piezoelectric actuator arranged on both sides of the intermediate beam; the first piezoelectric actuator and the second piezoelectric actuator can be synchronously extended and retracted in opposite directions along the front-to-back direction; the first piezoelectric actuator and the second piezoelectric actuator are respectively hinged to the adapter.

[0006] Optionally, the first piezoelectric actuator, the second piezoelectric actuator and the adapter are hinged in a point contact manner.

[0007] Optionally, the first piezoelectric actuator and the second piezoelectric actuator are respectively connected to the adapter via steel balls, forming a spherical hinge at the connection.

[0008] Optionally, the contact area at the connection between the first piezoelectric actuator and the adapter is smaller than the cross-sectional area of ​​the main body of the first piezoelectric actuator, thereby reducing the contact area between the first piezoelectric actuator and the adapter; the contact area at the connection between the second piezoelectric actuator and the adapter is smaller than the cross-sectional area of ​​the main body of the second piezoelectric actuator, thereby reducing the contact area between the second piezoelectric actuator and the adapter, so as to reduce the equivalent torsional stiffness of each connection and form an approximately spherical hinge.

[0009] Optionally, through grooves are provided on both sides of the middle beam near the adapter, so that the thickness of the beam at the grooves is smaller than the thickness of the main body of the middle beam, forming a flexible hinge structure.

[0010] Optionally, the first piezoelectric actuating portion and the second piezoelectric actuating portion are not in contact with the middle beam.

[0011] Optionally, the rear end of the fast axis actuator is connected to the base.

[0012] Optionally, the slow-axis actuator is a piezoelectric structure.

[0013] A second aspect of an embodiment of the present invention provides a scanning display module, comprising an optical fiber and the scanning actuator as described in the first aspect, wherein the optical fiber is fixed at the front end of the slow-axis actuator.

[0014] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0015] In the scheme of the embodiment of the present utility model, the scanning actuator includes a base, a fast-axis actuator, an adapter and a slow-axis actuator, and the adapter is connected to the base through an intermediate beam; the rear end of the slow-axis actuator is connected to the adapter; the fast-axis actuator includes a first piezoelectric actuator and a second piezoelectric actuator arranged on both sides of the intermediate beam; the first piezoelectric actuator and the second piezoelectric actuator can perform synchronous opposite expansion and contraction along the front-to-back direction; the first piezoelectric actuator and the second piezoelectric actuator do not contact the intermediate beam; the first piezoelectric actuator and the second piezoelectric actuator are respectively hinged to the adapter; when the scanning actuator vibrates, the fast-axis actuator and the slow-axis actuator can transmit force along the front-to-back direction through the hinged manner, and limit the transmission of torsional force, thereby alleviating the coupling problem between the fast and slow axes, avoiding the bifurcation of odd vertical lines and even vertical lines of the scanning trajectory, and improving the projection display quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without inventive work:

[0017] Figure 1 A side view of a scanning actuator provided in an embodiment of the present invention;

[0018] Figure 2 A top view of a scanning actuator provided in an embodiment of the present utility model;

[0019] Figure 3 A side view of the fast axis actuator and the middle beam provided in an embodiment of the present utility model;

[0020] Figure 4 A top view of the fast axis actuator and the middle beam provided in an embodiment of the present utility model;

[0021] Figure 5 A side view of a scanning actuator with a groove formed on the middle beam provided by an embodiment of the present invention;

[0022] Figure 6 A top view of a scanning actuator with a groove formed on the middle beam provided by an embodiment of the present utility model;

[0023] Figure 7 A side view of the middle beam provided in an embodiment of the present utility model. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] like Figures 1-4As shown, an embodiment of the present invention provides a scanning actuator, comprising a base 100, a fast-axis actuator, an adapter 102 and a slow-axis actuator 103 arranged in sequence from back to front; the adapter 102 is connected to the base 100 through an intermediate beam 104; the rear end of the slow-axis actuator 103 is connected to the adapter 102; the fast-axis actuator comprises a first piezoelectric actuator 1010 and a second piezoelectric actuator 1011 arranged on both sides of the intermediate beam 104; the first piezoelectric actuator 1010 and the second piezoelectric actuator 1011 are not in contact with the intermediate beam 104; the first piezoelectric actuator 1010 and the second piezoelectric actuator 1011 are hinged to the adapter 102 respectively.

[0026] Driven by the driving signal, the first piezoelectric actuator 1010 and the second piezoelectric actuator 1011 can perform synchronous opposite expansion and contraction in the front-to-back direction, so that the front end of the fast-axis actuator vibrates at a high frequency in the horizontal left and right directions. Driven by the driving signal, the front end of the slow-axis actuator 102 vibrates at a low frequency in the vertical direction. During the vibration of the scanning actuator, the fast-axis actuator and the slow-axis actuator 103 can be hinged to transmit force in the front-to-back direction and limit the transmission of torsional force.

[0027] In the above scheme, since the first piezoelectric actuator 1010 and the second piezoelectric actuator 1011 are respectively hinged to the adapter 102, only the force along the front-to-back direction (axial direction) is transmitted between the fast-axis actuator and the slow-axis actuator 103, and no torsional force is transmitted, thereby alleviating the coupling problem between the fast and slow axes (i.e., between the fast-axis actuator and the slow-axis actuator 103), avoiding the bifurcation of the odd vertical lines and the even vertical lines of the scanning trajectory, and thus improving the projection display quality.

[0028] In the embodiment of the present invention, the rear end of the fast axis actuator is connected to the base 100. The connection between the front end of the fast axis actuator and the adapter 102 includes but is not limited to the following connection methods.

[0029] In a first possible implementation, the hinge connection between the first piezoelectric actuator 1010 and the adapter 102 may be a point contact hinge connection. Similarly, the hinge connection between the second piezoelectric actuator 1011 and the adapter 102 may also be a point contact hinge connection.

[0030] In a second possible implementation, the first piezoelectric actuator 1010 and the second piezoelectric actuator 1011 are respectively connected to the adapter 102 via steel balls, forming a spherical hinge at the connection. In the embodiment of the present invention, the steel balls can be removed to further simplify the structure.

[0031] In a third possible embodiment, the contact area between the fast-axis actuator and the adapter 102 can be reduced to reduce the equivalent torsional stiffness of the structure at that location, thereby forming an approximate spherical hinge effect. Specifically, the contact area at the connection between the first piezoelectric actuator 1010 and the adapter 102 is smaller than the cross-sectional area of ​​the main body of the first piezoelectric actuator 1010, thereby reducing the contact area between the first piezoelectric actuator and the adapter. The contact area at the connection between the second piezoelectric actuator 1011 and the adapter 102 is smaller than the cross-sectional area of ​​the main body of the second piezoelectric actuator 1011, thereby reducing the contact area between the second piezoelectric actuator 1011 and the adapter 102, thereby reducing the equivalent torsional stiffness of the structure at each connection, thereby achieving an approximate spherical hinge effect.

[0032] In a fourth possible implementation, as Figure 5-Figure 7 As shown, through grooves 105 are provided on both sides of the middle beam 104 near the adapter 102, so that the thickness of the beam at the groove 105 is less than the thickness of the main part of the middle beam 104. By reducing the thickness of the middle beam, the equivalent torsional stiffness of the structure is reduced, so that the torsional stiffness of the slow axis vibration plane is much higher than the torsional stiffness of the fast axis vibration plane, thereby achieving an effect similar to a flexible hinge structure.

[0033] In the embodiment of the present invention, the rear end of the slow-axis actuator 103 is connected to the adapter 102 . The slow-axis actuator 103 is a piezoelectric sheet structure, including a dual piezoelectric sheet structure, a single piezoelectric sheet structure, or a piezoelectric stack structure.

[0034] In the embodiment of the present invention, the adapter 102 is hinged so that it can only twist on the vibration plane of the fast-axis actuator, and is restricted from twisting in other directions, especially on the vibration plane of the slow-axis actuator 103. In this way, when the slow-axis actuator 103 vibrates, the root torsional reaction force of the slow-axis actuator 103 is restricted by the connecting hinge and cannot be transmitted to the fast-axis actuator, thereby preventing the frequency characteristics of the fast-axis actuator from changing due to changes in external stress, thereby preventing the formation of fast-slow axis coupling.

[0035] In the above scheme, in addition to effectively reducing or eliminating the root reaction force transmitted to the fast-axis actuator when the slow-axis actuator 103 vibrates, it can also reduce the non-horizontal plane torsion of the fast-axis actuator caused by component tolerance transmitted to the slow-axis actuator 103, thereby reducing or eliminating the vertical line bifurcation of the scanning track caused by the fast-slow axis coupling problem.

[0036] In the embodiment of the present invention, a pre-tightening screw may be added to the tail of the fast axis actuator to eliminate the end face centering offset caused by machining and assembly errors, increase the pre-tightening force, and improve the output of the piezoelectric material (such as piezoelectric ceramics).

[0037] Based on the same utility model concept, an embodiment of the utility model also provides a scanning display module, including an optical fiber and the scanning actuator in the above embodiment. Regarding the setting of the optical fiber, the end face of the slow axis actuator part fixes the optical fiber, and the optical fiber is not rigidly fixed to the adapter and the fast axis actuator part.

[0038] The scanning display module in the embodiment of the present invention can be applied to various scenarios, including but not limited to AR (English full name: Augmented Reality; Chinese name: Augmented Reality) equipment, laser TV, laser projector, vehicle-mounted projection, etc. In these application scenarios, one scanning display module can be used for projection display, or multiple scanning display modules can be used to collaboratively display multiple images or splice displays. The present invention does not impose any restrictions on this.

[0039] All features disclosed in this specification, or all steps in the disclosed methods or processes, except mutually exclusive features and / or steps, can be combined in any manner.

[0040] Any feature disclosed in this specification (including any appended claims, abstract and drawings), unless otherwise stated, may be replaced by other equivalent or similar features. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0041] The present invention is not limited to the aforementioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A scanning actuator, characterized in that: It comprises a base, a fast-axis actuator, a transition piece and a slow-axis actuator which are arranged in sequence from the rear to the front; the transition piece is connected to the base through an intermediate beam; the rear end of the slow-axis actuator is connected to the transition piece; the fast-axis actuator comprises a first piezoelectric actuator and a second piezoelectric actuator which are arranged on both sides of the intermediate beam; the first piezoelectric actuator and the second piezoelectric actuator can be synchronously extended and retracted in opposite directions along the front-rear direction; the first piezoelectric actuator and the second piezoelectric actuator are respectively hinged to the transition piece.

2. The scanning actuator according to claim 1, wherein: The first piezoelectric actuating part, the second piezoelectric actuating part and the adapter are hinged in a point contact hinge manner.

3. The scanning actuator according to claim 2, characterized in that The first piezoelectric actuator and the second piezoelectric actuator are respectively connected to the adapter through steel balls, forming a spherical hinge at the connection.

4. The scanning actuator according to claim 1, wherein: The contact area at the connection between the first piezoelectric actuator and the adapter is smaller than the cross-sectional area of ​​the main body of the first piezoelectric actuator, thereby reducing the contact area between the first piezoelectric actuator and the adapter; the contact area at the connection between the second piezoelectric actuator and the adapter is smaller than the cross-sectional area of ​​the main body of the second piezoelectric actuator, thereby reducing the contact area between the second piezoelectric actuator and the adapter, so as to reduce the equivalent torsional stiffness of each connection and form an approximately spherical hinge.

5. The scanning actuator according to claim 1, wherein: Through grooves are provided on both sides of the middle beam near the adapter, so that the thickness of the beam at the grooves is smaller than the thickness of the main body of the middle beam, forming a flexible hinge structure.

6. The scanning actuator according to claim 1, wherein: The first piezoelectric actuator and the second piezoelectric actuator are not in contact with the middle beam.

7. The scanning actuator according to claim 1, wherein: The rear end of the fast axis actuator is connected to the base.

8. The scanning actuator according to claim 1, wherein: The slow axis actuator is a piezoelectric sheet structure.

9. A scanning display module, characterized in that: The invention comprises an optical fiber and a scanning actuator as claimed in any one of claims 1 to 8, wherein the optical fiber is fixed at the front end of the slow axis actuator.

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