A scanning display device comprising an optical fiber scanner

Abstract

The application discloses a scanning display device comprising a fiber scanner, which comprises a one-dimensional fiber scanner and a one-dimensional galvanometer scanner; a light beam emitted by the one-dimensional fiber scanner is incident on a mirror of the one-dimensional galvanometer scanner; the mirror reflects the incident light beam to an imaging plane, so that two-dimensional scanning display of an image is realized; the one-dimensional fiber scanner further comprises a shell; an actuator and a fiber cantilever of the one-dimensional fiber scanner are packaged in the shell; two flow guides are arranged in the shell and are separately arranged on two sides of the fiber cantilever; and the spacing between the flow guides and the fiber cantilever is set to be a laminar flow mode of gas flow between the flow guides and the fiber cantilever in the process of swinging of the fiber cantilever driven by the actuator.

Description

Technical Field

[0001] This application relates to the field of scanning display technology, and more particularly to a scanning display device including a fiber optic scanner. Background Technology

[0002] Fiber optic scanning imaging is a technology that uses precise oscillation at the end of an optical fiber to construct images point by point. Its core principle is to transmit a modulated light source through a single optical fiber and use rapid scanning at the fiber end to project light spots onto a screen or directly onto the observer's retina. By controlling the brightness, color, and position of these light spots, a complete image is formed. The brightness, color, and on / off state of the projected light spots are controlled through light source modulation to display the correct pixel information at each scanned location.

[0003] Specifically, one or more high-speed modulated light sources are used, and their optical signals are coupled into a flexible optical fiber. By precisely controlling the rapid two-dimensional oscillation at the end of the fiber, the light spots emitted from the fiber scan the target plane. Simultaneously, the intensity and color of the light sources are modulated synchronously according to the image data, so that the optical information of the corresponding pixel is projected at each point on the scanning path. Due to the persistence of vision, when the scanning speed is fast enough, these rapidly moving and changing light spots will merge into a complete, continuous image.

[0004] The advantage of this technology is that it can achieve miniaturized, high-resolution displays, which are especially suitable for near-field displays (such as AR / VR glasses), endoscopic imaging, and some special projection applications.

[0005] Precise synchronization between fiber optic oscillation and light source modulation is crucial for fiber optic scanning imaging to produce clear and stable images. The system must accurately know the position of the fiber optic end at any given moment and modulate the light source to output the correct optical information (brightness, color) accordingly.

[0006] Therefore, precise control of the two-dimensional oscillation is crucial for achieving high-definition, high-stability images. Its control precision directly affects pixel positioning accuracy, image geometry, and overall display quality. How to precisely control the fiber optic oscillation becomes a critical technical challenge that needs to be addressed. Utility Model Content

[0007] This application provides a scanning display device including a fiber optic scanner to improve the stability of fiber optic swing.

[0008] In practice, the inventors discovered that to avoid the influence of the surrounding environment on fiber optic oscillation, a preferred technical approach is to seal the fiber optic scanner, thus placing the vibrating component in a sealed space isolated from the outside world. However, even within a sealed space, the fiber optic scanner still suffers from inaccurate fiber optic oscillation control. The inventors attempted to evacuate the sealed space and ensure its vacuum level, which solved the problem of inaccurate fiber optic oscillation control. However, the requirement for a high vacuum level in the packaging necessitates a high sealing rating for the packaging structure, thereby increasing the requirements for the product manufacturing process and raising production costs.

[0009] Therefore, how to solve the problem of fiber optic oscillation without vacuum packaging has become a technical issue that needs to be addressed.

[0010] To achieve the above objectives, this application provides a fiber optic scanner, which includes a one-dimensional fiber optic scanner and a one-dimensional galvanometer scanner.

[0011] A one-dimensional fiber optic scanner includes an actuator and an optical fiber cantilevered at the end of the actuator. The fiber optic cantilever reciprocates along a first direction under the drive of the actuator.

[0012] The one-dimensional galvanometer scanner includes an actuator and a mirror mounted on a rotating shaft. The actuator drives the mirror to oscillate in a one-dimensional reciprocating angular direction about the axis of rotation along a second direction. The axis of rotation is parallel to the first direction, therefore the second direction is perpendicular to the first direction.

[0013] The light beam emitted from the one-dimensional fiber optic scanner is incident on the reflector of the one-dimensional galvanometer scanner. The reflector reflects the incident light beam onto the imaging plane, thereby realizing the two-dimensional scanning display of the image.

[0014] The one-dimensional fiber optic scanner also includes a housing. The actuator and fiber optic cantilever of the one-dimensional fiber optic scanner are both encapsulated in the housing. Two flow guides are disposed on both sides of the fiber optic cantilever. The flow guides are parallel to the first direction. The distance between the flow guides and the fiber optic cantilever is set such that the gas flow mode between the flow guides and the fiber optic cantilever is laminar during the process of the fiber optic cantilever swinging driven by the actuator.

[0015] The principle of the two-dimensional imaging display in this application is as follows: the fiber optic cantilever of the one-dimensional fiber optic scanner performs a one-dimensional reciprocating swing (e.g., horizontally), which defines the pixels in a row of the image. The reflector performs a one-dimensional angular reciprocating swing (e.g., vertically), which causes the "line" formed by the fiber optic scanning to move in another dimension, thereby constructing a two-dimensional image line by line. Preferably, the scanning mode of the scanning display device is raster scanning. The fiber optic scans a row quickly, then the reflector moves down a small angle, and the fiber optic scans the next row, and so on, until the entire two-dimensional area is covered.

[0016] Preferably, the axis of rotation is located within the plane of the reciprocating oscillation of the fiber optic cantilever. That is, the linear beam emitted from the fiber optic cantilever of the one-dimensional fiber optic scanner during its one-dimensional reciprocating oscillation is precisely incident on the rotation center of the reflector.

[0017] Preferably, the extension length of the guide plate in the fiber cantilever extension direction is not less than the length of the fiber cantilever, so that the entire fiber cantilever is located within the guide plate. Preferably, the length of the guide plate in the fiber cantilever swing direction is not less than the swing amplitude of the fiber under the actuator drive, so that the entire fiber cantilever is located within the guide plate during the swing process.

[0018] One or more technical solutions in the embodiments of this application have at least the following technical effects or advantages:

[0019] This application innovatively incorporates a guide plate on each side of the fiber optic cantilever to direct airflow, and combines it with a one-dimensional fiber optic scanner and a one-dimensional galvanometer scanner to achieve two-dimensional scanning. This organic combination achieves the technical effect of actively managing airflow in non-vacuum environments to mitigate the impact of airflow on the vibration of the fiber optic scanning cantilever, thus overcoming a key technical bottleneck. The entire system exhibits unexpectedly high precision performance in non-vacuum environments, performance typically found only in vacuum environments. Compared to one-dimensional or two-dimensional fiber optic scanners requiring vacuum encapsulation, this method reduces cost, simplifies the system, expands the application range, and achieves accuracy close to or at the same level. It avoids the increased cost and failure risks associated with vacuum encapsulation. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this application;

[0021] Figure 2 A schematic diagram of the fiber optic cantilever swinging within the guide plate;

[0022] Figure 3 Schematic diagram of the structure with fiber optic cantilever on both sides of the flow guide plate;

[0023] Figure 4 Simulation diagram of airflow velocity distribution near the fiber end face inside the packaging housing of the optical fiber cantilever;

[0024] Figure 5 Simulation diagram of airflow velocity distribution near the fiber end face inside the packaging shell after the addition of the flow guide plate;

[0025] Figure 6 Simulation diagram of airflow velocity distribution near the fiber end face inside the packaging shell after the distance between the flow guide plate and the fiber cantilever is appropriately increased;

[0026] Figure 7This is a simulation diagram of the airflow velocity distribution near the fiber end face inside the packaging shell when the gap between the flow guide plate and the fiber cantilever is too large. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0028] like Figure 1 As shown, this application provides a scanning display device including a fiber optic scanner, comprising a one-dimensional fiber optic scanner 100 and a one-dimensional galvanometer scanner 200.

[0029] The one-dimensional fiber optic scanner 100 includes an actuator 101 and an optical fiber cantilevered at the end of the actuator 101. The fiber optic cantilever 102 reciprocates along a first direction under the drive of the actuator 101.

[0030] The one-dimensional galvanometer scanner 200 includes an actuator 101 and a reflector 201 mounted on a rotating shaft. The actuator 101 drives the reflector 201 to perform one-dimensional reciprocating angular oscillation around the axis of rotation along a second direction. The axis of rotation is parallel to the first direction, therefore the second direction is perpendicular to the first direction.

[0031] The light beam emitted from the one-dimensional fiber optic scanner 100 is incident on the reflector 201 of the one-dimensional galvanometer scanner 200. The reflector 201 reflects the incident light beam onto the imaging plane, thereby realizing the two-dimensional scanning display of the image.

[0032] Combination Figure 2 , Figure 3 As shown, the one-dimensional fiber scanner 100 also includes a housing 300. The actuator 101 and the fiber cantilever 102 of the one-dimensional fiber scanner 100 are both encapsulated in the housing 300. Two flow guide plates 400 are respectively disposed on both sides of the fiber cantilever 102 in the housing 300. The flow guide plates 400 are parallel to the first direction. The distance between the flow guide plates 400 and the fiber cantilever 102 is set such that when the fiber cantilever 102 is driven by the actuator 101 to swing, the gas flow mode between the flow guide plates 400 and the fiber cantilever 102 is laminar flow.

[0033] This application innovatively incorporates a guide plate 400 on each side of the fiber optic cantilever 102 to guide airflow, and combines it with a one-dimensional fiber optic scanner 100 and a one-dimensional galvanometer scanner 200 to achieve a two-dimensional scanning method. This organic combination achieves the technical effect of actively managing airflow in non-vacuum environments to address the impact of airflow on the vibration of the fiber optic scanning cantilever, thus overcoming a key technical bottleneck. The entire system exhibits unexpectedly high precision performance in non-vacuum environments, performance typically found only in vacuum environments. Compared to one-dimensional or two-dimensional fiber optic scanners requiring vacuum encapsulation, this method reduces cost, simplifies the system, expands the application range, and achieves accuracy close to or at the same level. It avoids the increased cost and failure risks associated with vacuum encapsulation.

[0034] The principle of the two-dimensional imaging display in this application is as follows: The fiber cantilever 102 of the one-dimensional fiber scanner 100 performs a one-dimensional reciprocating swing (e.g., horizontal direction), which defines the pixels in a row of the image. The reflector 201 performs a one-dimensional angular reciprocating swing (e.g., vertical direction), which causes the "line" formed by the fiber scanning to move in another dimension, thereby constructing a two-dimensional image line by line. Preferably, the scanning mode is raster scanning. The fiber scans a row quickly, then the reflector moves down a small angle, and the fiber scans the next row, and so on, until the entire two-dimensional area is covered.

[0035] Preferably, the axis of rotation is located within the plane where the fiber optic cantilever 102 reciprocates. That is, the linear beam emitted from the fiber optic cantilever 102 of the one-dimensional fiber optic scanner 100 during its one-dimensional reciprocating oscillation is precisely incident on the rotation center of the reflector 201.

[0036] Preferably, the extension length of the guide plate 400 in the extension direction of the optical fiber cantilever 102 is not less than the length of the optical fiber cantilever 102, so that the entire optical fiber cantilever 102 is located within the guide plate 400; the length of the guide plate 400 in the swing direction of the optical fiber cantilever 102 is not less than the swing amplitude of the optical fiber under the drive of the actuator 101, so that the entire optical fiber cantilever 102 is located within the guide plate 400 during the swing.

[0037] Setting the spacing range between the flow guide plate 400 and the fiber optic cantilever 102 to ensure that the gas flow mode between the flow guide plate 400 and the fiber optic cantilever 102 is laminar during the swinging process of the fiber optic cantilever 102 is a conventional design for those skilled in the art.

[0038] Calculations can be performed using fluid dynamics, but a more preferred method is simulation verification and experimental optimization. Using computational fluid dynamics (CFD) software (such as ANSYS Fluent or COMSOL Multiphysics) to simulate the spacing design is the most accurate verification method. The final optimal spacing may still need to be fine-tuned experimentally. Several sets of guide vanes with different spacings can be fabricated, and the optimal value can be determined by using a laser Doppler velocimeter (LDV) or observing the stability of the scanning trajectory.

[0039] For fluid dynamics calculations, this application provides a calculation method for reference.

[0040] The Reynolds number is a dimensionless number in fluid mechanics used to determine whether a fluid flow is laminar or turbulent. Its formula is:

[0041]

[0042] in:

[0043] ρ: Fluid density (kg / m³) 3 (This is the air density, approximately 1.29 kg / m³) 3 )

[0044] v: Characteristic velocity of the fluid relative to the object (m / s) (Here, it is the maximum oscillation speed of the optical fiber)

[0045] L: Characteristic length (m)

[0046] μ: Dynamic viscosity coefficient (Pa·s) (The dynamic viscosity of air is approximately 17.9 × 10⁻⁶ Pa·s) -6 Pa·s)

[0047] In the field of fluid mechanics, when the Reynolds number Re is below about 2000, it can be considered as laminar flow. For the case of fluid flowing between flat plates, the characteristic length L = 2d in the formula for calculating the Reynolds number of fluid between flat plates is d, where d is the distance between the flat plates.

[0048] The maximum oscillation speed v of the optical fiber max =2πfA, f: oscillation frequency (Hz), A: oscillation half amplitude (m).

[0049] Therefore, the critical Reynolds number Re is set. max =2000, therefore, to maintain laminar flow

[0050]

[0051] Therefore, the maximum allowable spacing is:

[0052] The maximum allowable spacing d is calculated using the above formula. maxThis is the theoretical upper limit to ensure laminar airflow between the deflectors. It is recommended to allow for some margin in practical applications, taking a value slightly smaller than the calculated value, such as 80%-90% of the calculated value.

[0053] Minimum spacing d min It is mainly determined by physical constraints and boundary layer effects.

[0054] Physical limitations: The spacing must be greater than the diameter of the optical fiber itself, and sufficient safety margin must be allowed for installation errors, vibrations, etc. For example:

[0055] d min >Fiber diameter + 2 × maximum position error.

[0056] Boundary layer effect: The air velocity close to the guide plate approaches zero, forming a "boundary layer." If the spacing is too small, the two boundary layers will occupy most of the space, significantly increasing air viscous drag and affecting the fiber optic oscillation. A rule of thumb is that the minimum spacing should be at least several times the fiber diameter; the specific value needs to be optimized through experiments or simulations. The spacing range between the plates has been determined, which is also the spacing range between the guide plate 400 and the fiber cantilever 102.

[0057] The advantages of this application are described below through comparative embodiments.

[0058] Figure 4 The diagram illustrates the airflow near the fiber optic end face within the encapsulation housing 300. High-speed vibration of the fiber optic cable drives airflow near it. This high-speed airflow, after detaching from the fiber, impacts the inner wall and, upon encountering resistance, flows in the opposite direction, merging with the airflow near the fiber to create more complex turbulence. This instability in the airflow near the fiber leads to unstable fiber vibration, ultimately causing scanning trajectory jitter and display screen flicker.

[0059] Figure 5 As shown, after adding the guide plate 400, the gas flow pattern near the fiber end face is laminar. Even if the gas flows out of the guide plate and impacts the inner wall, creating turbulence, it will be isolated from the fiber cantilever and return to laminar flow before re-flowing into the guide plate 400. The guide plate 400 effectively suppresses turbulence on both sides of the fiber cantilever. Compared to... Figure 4 The embodiment shown effectively solves the technical problem of scanning trajectory jitter and display screen jitter.

[0060] Figure 6 compared to Figure 5 In the illustrated embodiment, the spacing between the guide plates 400 is appropriately increased to accommodate assembly tolerances and prevent the fiber optic cantilever from contacting the guide plates 400. The turbulence suppression effect is also relatively significant.

[0061] Figure 7 compared to Figure 6In the illustrated embodiment, further increasing the spacing results in an excessively wide spacing between the guide plates 400, causing significant turbulence on both sides of the fiber cantilever. Consequently, the guide plates 400 no longer have a turbulence suppression effect, leading to further jitter in the scanning trajectory and display screen.

[0062] It should be noted that the above embodiments are illustrative of this application and not limiting of it, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The words “comprising” or “including” do not exclude the presence of elements or steps not listed in the claims. The words “a” or “an” preceding an element do not exclude the presence of a plurality of such elements. The use of the words first, second, and third, etc., does not indicate any order and these words can be interpreted as names.

[0063] All features disclosed in this specification, except for mutually exclusive features, can be combined in any way.

[0064] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0065] This application is not limited to the specific embodiments described above. This application extends to any new features or combinations disclosed in this specification, as well as any new steps or combinations of any new methods or processes disclosed.

Claims

1. A scanning display device including a fiber optic scanner, characterized in that, Including a one-dimensional fiber optic scanner and a one-dimensional galvanometer scanner, A one-dimensional fiber optic scanner includes an actuator and an optical fiber cantilevered at the end of the actuator. The fiber optic cantilever reciprocates along a first direction under the drive of the actuator. The one-dimensional galvanometer scanner includes an actuator and a mirror mounted on a rotating shaft. The actuator drives the mirror to oscillate in a one-dimensional reciprocating angular direction about the axis of rotation along a second direction. The axis of rotation is parallel to the first direction, therefore the second direction is perpendicular to the first direction. The light beam emitted from the one-dimensional fiber optic scanner is incident on the reflector of the one-dimensional galvanometer scanner. The reflector reflects the incident light beam onto the imaging plane, thereby realizing the two-dimensional scanning display of the image. The one-dimensional fiber optic scanner also includes a housing. The actuator and fiber optic cantilever of the one-dimensional fiber optic scanner are both encapsulated in the housing. Two flow guides are disposed on both sides of the fiber optic cantilever. The flow guides are parallel to the first direction. The distance between the flow guides and the fiber optic cantilever is set such that the gas flow mode between the flow guides and the fiber optic cantilever is laminar during the process of the fiber optic cantilever swinging driven by the actuator.

2. The scanning display device including a fiber optic scanner as described in claim 1, characterized in that, The axis of rotation is located in the plane where the optical fiber cantilever reciprocates.

3. A scanning display device including a fiber optic scanner as described in claim 1, characterized in that, The extension length of the guide plate in the direction of the fiber cantilever extension is not less than the length of the fiber cantilever, so that the entire fiber cantilever is located inside the guide plate.

4. A scanning display device including a fiber optic scanner as described in claim 1 or 3, characterized in that, The length of the guide plate in the direction of the fiber cantilever swing is not less than the swing amplitude of the fiber under the actuator drive, so that the entire fiber cantilever is located inside the guide plate during the swing process.

5. A scanning display device including a fiber optic scanner as described in claim 1, characterized in that, Its scanning mode is raster scanning.

6. A scanning display device including a fiber optic scanner as described in claim 5, characterized in that, The fiber cantilever of the one-dimensional fiber scanner oscillates in one dimension, which defines the pixels in a row of the image. The mirror oscillates in one dimension at an angle, which causes the lines formed by the fiber scanning to move in another dimension, thus constructing a two-dimensional image line by line.

7. A scanning display device including a fiber optic scanner as described in claim 6, characterized in that, The optical fiber quickly scans one line, then the mirror moves down a tiny angle, and the optical fiber scans the next line, repeating this process until the entire two-dimensional area is covered.

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