A scanning driving method and a scanning device

Abstract

This invention discloses a scanning driving method and a scanning device. The scanning device includes a first actuating part and a second actuating part. The first actuating part is capable of vibrating in a first direction, and the second actuating part is capable of driving the first actuating part to vibrate in a second direction. The method includes: when driving the scanning device to vibrate, the first actuating part and the second actuating part vibrate under the action of their respective driving signals, and a correction signal applied to at least one actuating part includes a signal corresponding to the nonlinear response frequency of the scanning device. This solution addresses the problem of abnormal scanning trajectories caused by the nonlinearity of fiber optic scanning imaging systems in the prior art, thereby improving projection effects.

Description

Technical Field

[0001] This invention relates to the field of scanning imaging, and more particularly to a scanning driving method and a scanning device. Background Technology

[0002] Fiber optic scanning imaging systems utilize actuators in fiber optic scanners to drive high-speed vibration of the optical fiber, combined with laser modulation algorithms, to display image information. To increase the swing amplitude of the optical fiber, the driving frequency of the actuator can be made close to the natural frequency of the optical fiber, thereby driving the actuator to resonate with the scanning fiber and achieving a larger swing amplitude.

[0003] Since real-world systems are nonlinear, their response to input excitation is always a continuous spectrum, with the nonlinearity being particularly strong near the resonance point. For single or mixed-frequency input signals, prominent additional frequency components will be detected in the output signal, i.e., the optical fiber's scanning trajectory signal. These responses caused by the system's nonlinearity lead to anomalies in the scanning trajectory, such as non-closed, curved, or misaligned scanning curves, affecting the display quality. The purpose of this solution is to address the problem of abnormal scanning trajectories caused by the nonlinearity of fiber optic scanning imaging systems. Summary of the Invention

[0004] The purpose of this invention is to provide a scanning driving method and scanning device to solve the problem of abnormal scanning trajectory caused by the nonlinearity of fiber optic scanning imaging systems in the prior art.

[0005] To achieve the above-mentioned objective, a first aspect of the present invention provides a scanning driving method applied in a scanning device, the scanning device including a first actuating part and a second actuating part, the first actuating part being capable of vibrating in a first direction, and the second actuating part being capable of driving the first actuating part to vibrate in a second direction, the method including:

[0006] When the scanning device is driven to vibrate, the first actuator and the second actuator vibrate under the action of their respective driving signals, and the correction signal applied to at least one actuator includes a signal corresponding to the nonlinear response frequency of the scanning device.

[0007] Optionally, the nonlinear response frequency of the scanning device includes one or more preset frequency points.

[0008] Optionally, the one or more frequency points are determined according to expression f. i =±m*f x ±n*f y The calculation yields the result; where m and n are non-negative integers, and f... x f is the first driving frequency. yThe second driving frequency is the driving frequency of the first actuator and the second driving frequency is the driving frequency of the second actuator.

[0009] Optionally, the one or more frequency points are determined according to expression f. i =±m*f x ±f y / n is calculated; where m and n are non-negative integers, f x f is the first driving frequency. y The second driving frequency is the driving frequency of the first actuator and the second driving frequency is the driving frequency of the second actuator.

[0010] Optionally, m and n are integers less than or equal to 5.

[0011] Optionally, the scanning device is an optical fiber scanner. When the nonlinear response frequency of the optical fiber scanner includes multiple frequency points, the frequency point closest to the inherent frequency of the optical fiber is selected as the frequency point of the corresponding correction signal.

[0012] Optionally, when the nonlinear response frequency of the scanning device includes multiple frequency points, the method for selecting the frequency points includes:

[0013] The scanning trajectory of the scanning device is detected, and the trajectory features of the scanning trajectory are identified;

[0014] Based on the correspondence between the frequency points and the trajectory features, the frequency point corresponding to the trajectory features is selected from the plurality of frequency points as the frequency point of the corresponding correction signal.

[0015] Optionally, the method further includes:

[0016] When the scanning device is in scanning mode, monitor the changes in the scanning trajectory of the scanning device or the preset graphic features;

[0017] Adjust the amplitude and phase of the signal corresponding to the nonlinear response frequency until the scanning trajectory or preset pattern of the scanning device meets the preset conditions.

[0018] Optionally, the correction signal applied to the first actuator includes a signal corresponding to the driving frequency of the second actuator and a signal corresponding to the nonlinear response frequency;

[0019] The correction signal applied to the second actuator includes a signal corresponding to the driving frequency of the first actuator and a signal corresponding to the nonlinear response frequency.

[0020] A second aspect of the present invention provides a scanning device, including a first actuation part and a second actuation part. The first actuation part is capable of vibrating in a first direction, and the second actuation part is capable of driving the first actuation part to vibrate in a second direction. When the scanning device is in a scanning state, the first actuation part and the second actuation part vibrate under the action of their respective driving signals. The correction signal applied to at least one actuation part includes a signal corresponding to the nonlinear response frequency of the scanning device.

[0021] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0022] In the embodiment of the present invention, in addition to the original driving signal, an additional response frequency point is added to the input signal. This response frequency point can be calculated based on the fast axis driving frequency and the slow axis driving frequency. The additional response frequency point is used to correct the spectral components of the nonlinear response signal, thereby solving the problem of abnormal scanning trajectory caused by the nonlinearity of the fiber optic scanning imaging system in the prior art, so that the scanning trajectory of the fiber optic scanner can achieve a better effect and improve the projection effect. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. 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 creative effort:

[0024] Figure 1A-Figure 1B This is a schematic diagram of the fiber optic scanning imaging system in an embodiment of the present invention;

[0025] Figure 1C This is a schematic diagram of the result of a possible actuator in an embodiment of the present invention;

[0026] Figure 2 A flowchart of a scanning driving method provided in an embodiment of the present invention;

[0027] Figures 3A-5 A schematic diagram of the scan trajectory for raster scanning;

[0028] Figures 6A-6C This is a schematic diagram of the scanning trajectory of a Lissajous scan. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] In this embodiment of the invention, the scanning device can be a fiber optic scanner or a MEMS (Micro-Electro-Mechanical Systems) scanning mirror. In this embodiment, a fiber optic scanner is used as an example for illustration. For other forms of scanning devices, such as MEMS scanning mirrors, the laser beam is deflected through a two-dimensional galvanometer (the scanning mode can be grid scanning or Lissajous scanning). This device itself also has a strong nonlinear effect, so it is also applicable to the scheme in this embodiment of the invention.

[0031] This manual first describes the fiber optic scanning imaging system. The fiber optic scanning imaging system utilizes an actuator in the fiber optic scanner to drive the fiber optic cable to vibrate at high speed, and in conjunction with a laser modulation algorithm, displays image information. For example... Figure 1A As shown, this is an existing fiber optic scanning imaging system, which mainly includes: a processor 100, a laser module 110, a fiber optic scanner 120, a transmission fiber optic cable 130, a light source modulation circuit 140, a scanning drive circuit 150, and a beam combining unit 160.

[0032] The processor 100 can be a graphics processing unit (GPU), a central processing unit (CPU), or other chips or circuits with control and image processing functions, without being specifically limited here.

[0033] During system operation, the processor 100 controls the light source modulation circuit 140 to modulate the laser module 110 according to the image data to be displayed. The laser module 110 contains multiple monochromatic lasers, each emitting a beam of a different color. Figure 1A As can be seen, the laser module can specifically use red (R), green (G), and blue (B) lasers. The beams emitted by each laser in the laser module 110 are combined into a single laser beam by the beam combining unit 160 and coupled into the transmission optical fiber 130.

[0034] The processor 100 can also control the scanning drive circuit 150 to drive the fiber optic scanner 120 to perform scanning, thereby scanning and outputting the beam transmitted in the transmission fiber optic 130.

[0035] The light beam output by the fiber optic scanner 120 acts on a specific pixel location on the medium surface, forming a light spot at that pixel location, thus achieving scanning of that pixel location. Driven by the fiber optic scanner 120, the output end of the transmission fiber optic cable 130 sweeps along a certain scanning trajectory, thereby moving the light beam to the corresponding pixel location for scanning. During the actual scanning process, the light beam output by the transmission fiber optic cable 130 will form a light spot with corresponding image information (such as color, grayscale, or brightness) at each pixel location. Within one frame, the light beam traverses each pixel location at a sufficiently high speed to complete the scanning of one frame of image. Due to the characteristic of "visual persistence" in human vision, the human eye cannot perceive the movement of the light beam at each pixel location, but instead sees a complete frame of image.

[0036] Continue to refer to Figure 1B The existing fiber optic scanner 120 has the following structure, mainly including: a piezoelectric actuator 121, a fiber optic cantilever 122, a lens 123, a scanner housing 124, and a fixing member 125. The piezoelectric actuator 121 is fixed in the scanner housing 124 by the fixing member 125. The transmission fiber 130 extends from the free end of the piezoelectric actuator 121 to form the fiber optic cantilever 122 (also called a scanning fiber). During operation, the piezoelectric actuator 121 vibrates along the x-axis and x-axis directions under the drive of the scanning drive signal. Driven by the piezoelectric actuator 121, the free end of the fiber optic cantilever 122 sweeps along a preset trajectory and emits a light beam. The emitted light beam can then scan the medium surface through the lens 123. Here, the y-axis is also called the slow axis, and the x-axis is also called the fast axis. The y-axis direction intersects the x-axis direction; obviously, the y-axis direction and the x-axis direction can be perpendicular.

[0037] For piezoelectric actuator 121, such as Figure 1C As shown, the device includes a first actuating part 1210 and a second actuating part 1211 sequentially from front to back. An optical fiber extends beyond the first actuating part 1210 to form an optical fiber cantilever 122. For raster scanning, the driving frequency of the first actuating part 1210 is generally greater than the driving frequency of the second actuating part 1211. Therefore, in this specification, the first actuating part 1210 is also referred to as a fast-axis actuator, and the second actuating part 1211 is also referred to as a slow-axis actuator. In the embodiments of the invention, the piezoelectric actuator 121 can be manufactured using a one-piece molding process, or it can be a non-one-piece structure. For example, the first actuating part 1210 and the second actuating part 1211 can be manufactured separately and connected by bonding, welding, precision welding, or a connecting structure. In other embodiments, the piezoelectric actuator 121 can also be a cylindrical or square tube, etc., and the present invention does not limit this.

[0038] Next, the scanning driving method in the embodiments of the present invention will be described.

[0039] In this embodiment of the invention, the drive signal applied to the first actuator is hereinafter referred to as the fast axis input signal U. x The drive signal applied to the second actuator is hereinafter referred to as the slow axis input signal U. x The first actuator is capable of vibrating in a first direction, hereinafter referred to as the x-direction, and the second actuator vibrates in a second direction, hereinafter referred to as the y-direction. x and U x They are represented as follows:

[0040]

[0041]

[0042] Among them, U x U y These are voltage signals in the x and y directions, respectively; A x A y The amplitudes of the voltage signals in the x and y directions are respectively; the first driving frequency f x Second driving frequency f y The frequencies of the drive signals in the x and y directions are respectively, and the first drive frequency f x Second driving frequency f y To determine the main frequency of the scanning motion in the corresponding direction; These represent the phases of the driving signals in the x and y directions, respectively.

[0043] Typically, due to the coupling effect of the fiber scanner itself, the responses of the two axes are coupled to each other, resulting in the actual responses of the fiber along the two axes containing each other's signal spectra. For example, the actual responses X and Y of the fiber along the fast axis are respectively:

[0044]

[0045]

[0046] Where X and Y are the vibration response signals at the tip of the fiber cantilever, and A1, A2, A3, and A4 are the amplitudes of each frequency signal component, respectively. These represent the response phases of the signals at each corresponding frequency.

[0047] Since it is difficult to completely avoid the coupling effect between the responses of the two axes during the scanning process of the fiber optic scanner, a correction signal component of the response spectrum can be added to both axes. The correction signal component can cancel the coupling signal, so that the trajectory matches the expectation. At this time, the input signal can be:

[0048]

[0049]

[0050] Among them, A' x A' y These are the amplitudes of the corresponding signals used for correction. This corresponds to the phase of the correction signal.

[0051] However, the inventors of this solution discovered that while the above processing is sufficient for systems with weak nonlinearity, in fiber optic scanning imaging systems, large-amplitude scanning is achieved using fiber resonance. Due to the extremely low damping of the fiber, the nonlinear effect is extremely strong. Furthermore, inter-axis coupling cannot be completely avoided in engineering, and prolonged operation may lead to performance changes and enhanced nonlinearity. Complex nonlinear effects will cause the trajectory to deviate from the expected trajectory, exhibiting twisted or non-closed curves and other complex patterns, resulting in pixel misalignment. The actual response of the fiber in the fast and slow axis directions is no longer as shown in the aforementioned expressions. In this case, the actual response of the fiber can be expressed as:

[0052]

[0053]

[0054] Among them, A i A j This is caused by the nonlinear effect of the system. In the fiber optic vibration response signal, besides the input signal f... x f y The i and j frequency components other than those, f i f j For the corresponding frequency, This represents the response phase of the corresponding signal.

[0055] Among them, the third item and This refers to the spectral components of the nonlinear response signal. Therefore, the spectral components corresponding to the nonlinear response signal should also be added to the actual driving signal to cancel out its response and make the trajectory normal.

[0056] like Figure 2 As shown, the scanning driving method in this embodiment of the invention includes the following steps.

[0057] Step 201: When driving the scanning device to vibrate, the first actuator and the second actuator generate vibration under the action of their respective driving signals, and the correction signal applied to at least one actuator includes a signal corresponding to the nonlinear response frequency of the scanning device.

[0058] That is, the final input signal can be expressed as:

[0059]

[0060]

[0061] Among them, U x and U y The third term is the correction signal corresponding to the nonlinear response frequency. A' i A j 'This refers to the amplitude of the input signal used to correct the frequency component of the nonlinear response in the correction signal.' This represents the phase of the corresponding signal.

[0062] Regarding the values ​​of i and j, their maximum values ​​vary depending on the actual display specifications and the system's accuracy requirements for error correction. Higher nonlinear order results in smaller nonlinear coefficients and lower effectiveness; therefore, fewer nonlinear correction signal components are actually needed, typically only two or three, or even just one, component is required to achieve the desired correction effect. Considering the improvement in display specifications and the higher accuracy requirements, more nonlinear spectra need to be corrected, and the maximum values ​​of i and j may be larger (i.e., more frequency components in the response). Generally, a maximum value of i and j not exceeding 5 is sufficient to meet the accuracy requirements. In some more complex systems or systems with higher accuracy requirements, the values ​​of i and j can also be integers greater than or equal to 5; this invention does not impose any restrictions on this.

[0063] In one possible implementation, the value f of the response frequency point i It can be based on the expression f i =±m*f x ±n*f y The calculation yields f, where m and n are non-negative integers. x f y These are the frequencies of the drive signals in the x-direction (fast axis direction) and y-direction (slow axis direction), respectively. In other words, given the frequencies in the x-direction and y-direction, the value f of the response frequency point... i The value is also definite. For example: f i =±f x ±f y f i =±f x ±2f y f i =±2f x ±f y And so on, the present invention does not limit this. Generally speaking, m and n being 5 or less can achieve good results.

[0064] For fiber optic scanners, the frequency of the nonlinear response signal is determined according to the rule f above. i =±m*f x ±n*f ySince m and n can take different values, multiple frequency points can exist simultaneously. Generally speaking, in f x and f y Given a certainty, f i f j It is a series of fixed values, which can be stored in the corresponding scanner or in the fiber optic scanning imaging system where the fiber optic scanner is located. i f j It is a series of fixed values, but its response magnitude and phase differ under different scanning conditions. For f i f j The frequency selection can be preset at the factory or dynamically adjusted based on the actual situation of the scanned image during the scanning process.

[0065] Next, we will explain the method for dynamically adjusting the selected frequency point during the scanning process. First, we will take the grating scanning mode of the fiber optic scanner as an example.

[0066] like Figure 3A As shown, when the fast and slow axes follow ideal trajectories, the image is square. However, for scan contour changes caused by nonlinear signals, such as... Figures 3B-3D As shown.

[0067] If the fast axis contains a nonlinear signal, when m = 1 and n = -1, the image is as follows. Figure 3B As shown, the target should be displayed as a vertical line, but it is actually displayed as an "open" ellipse.

[0068] If the fast axis contains a nonlinear signal, when m=1 and n=-2, and this signal has a phase difference compared to the original signal, the original signal is the response signal corresponding to the drive signal. The target display should be a vertical line, but the actual display shows two "opening" ellipses, such as... Figure 3C As shown.

[0069] If the fast axis contains a nonlinear signal, when m=1 and n=-3, there is a phase difference. The target display should show a vertical line, but the actual display shows an ellipse with three "openings," as shown below. Figure 3D As shown.

[0070] Similarly, if the slow axis contains a nonlinear signal, when m=1 and n=-1, the target should be displayed as a horizontal line, but the actual display shows an elliptical characteristic, such as... Figure 4A As shown.

[0071] If the slow axis contains a nonlinear signal, when m = 1 and n = -2, the profile is tilted and exhibits multiple ellipses with doubled periods, such as... Figure 4B As shown.

[0072] If both the fast and slow axes contain nonlinear signals, assuming the nonlinear signal on the fast axis is m=1, n=-2, and the nonlinear signal on the slow axis is m=1, n=-3, the profiles of both the fast and slow axes exhibit an "opening" characteristic, and there are differences, such as... Figure 5 As shown.

[0073] Similarly, for a Lissajous scan, the ideal trajectory is as follows: Figure 6A As shown.

[0074] If both the fast and slow axes contain nonlinear signals, assuming the nonlinear signal on the fast axis is m=1, n=2; and the nonlinear signal on the slow axis is m=3, n=-1, the graph would look like this: Figure 6B As shown.

[0075] If the fast axis contains a nonlinear signal, assuming m = 1 and n = -2, and the slow axis has no nonlinear signal, the graph is as follows. Figure 6C As shown.

[0076] The above are merely illustrative examples intended to demonstrate the impact of nonlinear response on the scanning trajectory and the necessity of correcting it. The accompanying diagrams are only some representative examples. In practical applications, the same method can be used to obtain the corresponding image features (i.e., trajectory features) for other different m / n values, which will not be detailed here. For the same m(n), but with opposite signs of n(m), the contours may exhibit similar characteristics, which can be distinguished by pre-defined distinctive graphic features. Therefore, during actual projection output, the detection light with distinctive graphic features used as feedback can be output through the same scanning fiber as the image light, and thus distinguished by the graphic features of the detection light.

[0077] The above analysis shows that nonlinear response has a significant impact on the scanning trajectory, directly determining the imaging display effect. Therefore, it is essential to correct or suppress the nonlinear response. Since different nonlinear spectra have corresponding image characteristics, these image characteristics can be used to determine the nonlinear spectral components (frequency points) to be corrected. In other words, during image correction, different image characteristics correspond to different frequency points. The corresponding frequency points are determined based on the actual image characteristics. After determining the frequency points, the amplitude and period are continuously adjusted. Through continuous iteration, the final scanned image meets the preset conditions, namely, the scanning trajectories of both the fast and slow axes approximate ideal trajectories, and the image is approximately square.

[0078] Generally speaking, the values ​​of frequencies closer to the fiber itself are more dominant, while the values ​​further away have less impact or can even be ignored. In specific implementation, the decision to further correct the more distant frequencies can be made based on the display effect.

[0079] Furthermore, based on system accuracy and error requirements, a frequency point with a greater impact can be selected for correction. Generally speaking, according to the relationship between the system's resonant frequencies, the frequency point closer to the fiber's natural frequency or fiber peak is chosen. i f j The component with the greatest effect is the first component that needs to be corrected. Then, depending on the display effect, it is decided whether further correction is needed for more distant frequency points.

[0080] In other embodiments, while ensuring system performance, as many frequency points as possible can be selected for correction to continuously optimize the display effect.

[0081] In another possible implementation, if the optical fiber is extremely nonlinear, spectral components of the following form may also appear: f i =±m*f x ±f y / n. Where m and n are positive integers, such as: f i =±f x ±f y f i =±f x ±f y / 2、f i =±2f x ±f y / 2, and so on. This invention does not limit this; generally, m and n being 5 or less can achieve good results. Similarly, the frequency selection method in the foregoing embodiments, and the corresponding method for dynamically adjusting the selected frequency, are also applicable to this embodiment. For the sake of brevity, they will not be described in detail here.

[0082] In this embodiment of the invention, during correction, the fast-axis actuator or the slow-axis actuator can be corrected individually, or both axes can be corrected simultaneously. For example, when correcting the fast-axis actuator alone, a fast-axis drive signal and a fast-axis correction signal are applied to the fast-axis actuator. The correction signal includes a signal corresponding to the drive frequency of the second actuator and a signal corresponding to the nonlinear response frequency. A slow-axis drive signal is then applied to the slow-axis actuator. Similarly, when correcting the slow-axis actuator alone, a slow-axis drive signal and a slow-axis correction signal are applied to the slow-axis actuator. The correction signal includes a signal corresponding to the drive frequency of the first actuator and a signal corresponding to the nonlinear response frequency. A fast-axis drive signal is then applied to the fast-axis actuator. Of course, both the fast-axis and slow-axis actuators can be corrected simultaneously to optimize the final projection effect.

[0083] In this embodiment of the invention, in addition to the frequency of the correction signal, it is also necessary to determine the amplitude and phase of the correction signal. For the amplitude and phase of the correction signal, changes in the scanning trajectory of the marked fiber optic scanner can be detected while adjusting the amplitude and phase. By iteratively adjusting the amplitude and phase of the correction signal until the scanning trajectory of the fiber optic scanner meets preset conditions, the required amplitude and phase of the correction signal can be obtained and fixed as the input of the correction signal. Here, the correction signal refers to the correction signal corresponding to the nonlinear response frequency. For the correction signal corresponding to the driving frequency, i.e., the mixing signal, the same method can be used to obtain the required amplitude and phase of the mixing signal. Furthermore, iterative adjustments can be made between the correction signal corresponding to the driving frequency and the correction signal corresponding to the nonlinear response frequency to obtain better display effects; these details will not be elaborated upon here.

[0084] In this embodiment of the invention, because fiber optic scanning imaging systems have high requirements for the accuracy of the scanning trajectory, they are generally equipped with a real-time or online detection system. This system monitors and controls changes in the scanning trajectory of the fiber optic scanner or pre-defined graphic features to obtain the actual response spectrum. Then, by adding the correction signal corresponding to the aforementioned nonlinear response frequency point, the amplitude and phase of the correction signal are continuously adjusted until the scanning trajectory meets preset conditions, i.e., the actual response spectrum of the fiber optic scanner meets the requirements. The preset conditions can be that the scanning trajectory of the fiber optic scanner is an approximately horizontal straight line, and the overall image is approximately square.

[0085] In this embodiment of the invention, the effect of the scanning trajectory of the fiber optic scanner is mainly judged based on the specific situation of the scanned image display. For example, the ideal situation is that the pixel spacing is uniform and there is no overlap; a better situation is that some pixels in a very local area overlap by less than one pixel or are misaligned; and a normal situation is that there are many positions or the whole image with pixel offset, but the offset (or overlap) is less than one pixel, which is just enough to be used for display, but the contrast is slightly low. Those skilled in the art can choose the correction accuracy and set the corresponding preset conditions according to their needs, and this invention does not limit this.

[0086] In this embodiment of the invention, the real-time or online detection system can be implemented using a camera or photoelectric detection device, such as a PSD (Position Sensitive Detector), to detect the scanning trajectory of the fiber optic scanner. During the factory settings or system initialization of the fiber optic scanning imaging system, detection can be performed using either visible or invisible light. However, during user operation of the fiber optic scanning imaging system, detection can be performed using invisible light, thus not affecting the user's viewing experience.

[0087] In the above embodiment, in addition to the original fast axis drive frequency and slow axis drive frequency, the input signal has an additional response frequency point. This response frequency point can be calculated based on the fast axis drive frequency and slow axis drive frequency. The additional response frequency point is used to correct the spectral components of the nonlinear response signal, thereby enabling the scanning trajectory of the fiber optic scanner to achieve a better effect.

[0088] Based on the same inventive concept, embodiments of the present invention also provide a scanning device, which includes a first actuating part and a second actuating part. The first actuating part is capable of vibrating in a first direction, and the second actuating part is capable of driving the first actuating part to vibrate in a second direction. When the scanning device is in a scanning state, the first actuating part and the second actuating part vibrate under the action of their respective driving signals. The correction signal applied to at least one actuating part includes a signal corresponding to the nonlinear response frequency of the scanning device. The determination of the nonlinear response frequency has been described in detail in the embodiments of the aforementioned scanning driving method, and will not be elaborated here.

[0089] In this embodiment of the invention, the fiber optic scanning imaging system may include one or more fiber optic scanners. When the system includes multiple fiber optic scanners, the images scanned by the multiple fiber optic scanners are stitched together to form a complete image. This fiber optic scanning imaging system can be applied to various projection display devices, such as AR (Augmented Reality) devices, laser TVs, laser projectors, etc., and its applications are very wide.

[0090] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0091] In the embodiment of the present invention, in addition to the original driving signal, an additional response frequency point is added to the input signal. This response frequency point can be calculated based on the fast axis driving frequency and the slow axis driving frequency. The additional response frequency point is used to correct the spectral components of the nonlinear response signal, thereby solving the problem of abnormal scanning trajectory caused by the nonlinearity of the fiber optic scanning imaging system in the prior art, so that the scanning trajectory of the fiber optic scanner can achieve a better effect and improve the projection effect.

[0092] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0093] 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.

[0094] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A scanning driving method, applied in a scanning device, characterized in that, The scanning device includes a first actuator and a second actuator, the first actuator being capable of vibrating in a first direction, and the second actuator being capable of driving the first actuator to vibrate in a second direction. The method includes: When the scanning device is driven to vibrate, the first actuator and the second actuator generate vibration under the action of their respective driving signals. The correction signal applied to at least one actuator includes a signal corresponding to the nonlinear response frequency of the scanning device. The nonlinear response frequency is calculated based on the first driving frequency and the second driving frequency. The first driving frequency refers to the driving frequency of the first actuator, and the second driving frequency refers to the driving frequency of the second actuator.

2. The method as described in claim 1, characterized in that, The nonlinear response frequency of the scanning device includes one or more preset frequency points.

3. The method as described in claim 2, characterized in that, The one or more frequency points are based on expression f i =±m*f x ±n*f y The calculation yields the result; where m and n are non-negative integers, and f... x f is the first driving frequency. y This is the second driving frequency.

4. The method as described in claim 2, characterized in that, The one or more frequency points are based on expression f i =±m*f x ±f y / n is calculated; where m and n are non-negative integers, f x f is the first driving frequency. y This is the second driving frequency.

5. The method as described in claim 3 or 4, characterized in that, The values ​​of m and n are integers less than or equal to 5.

6. The method as described in claim 3 or 4, characterized in that, The scanning device is an optical fiber scanner. When the nonlinear response frequency of the optical fiber scanner includes multiple frequency points, the frequency point closest to the inherent frequency of the optical fiber is selected as the frequency point of the corresponding correction signal.

7. The method as described in claim 3 or 4, characterized in that, When the nonlinear response frequency of the scanning device includes multiple frequency points, the method for selecting the frequency points includes: The scanning trajectory of the scanning device is detected, and the trajectory features of the scanning trajectory are identified; Based on the correspondence between the frequency points and the trajectory features, the frequency point corresponding to the trajectory features is selected from the plurality of frequency points as the frequency point of the corresponding correction signal.

8. The method as described in claim 6 or 7, characterized in that, The method further includes: When the scanning device is in scanning mode, monitor the changes in the scanning trajectory of the scanning device or the preset graphic features; Adjust the amplitude and phase of the signal corresponding to the nonlinear response frequency until the scanning trajectory or preset pattern of the scanning device meets the preset conditions.

9. The method as described in claim 1, characterized in that, The correction signal applied to the first actuator includes a signal corresponding to the driving frequency of the second actuator and a signal corresponding to the nonlinear response frequency; The correction signal applied to the second actuator includes a signal corresponding to the driving frequency of the first actuator and a signal corresponding to the nonlinear response frequency.

10. A scanning device, characterized in that, The device includes a first actuator and a second actuator. The first actuator is capable of vibrating in a first direction, and the second actuator is capable of driving the first actuator to vibrate in a second direction. When the scanning device is in a scanning state, the first actuator and the second actuator vibrate under the action of their respective driving signals. The correction signal applied to at least one actuator includes a signal corresponding to the nonlinear response frequency of the scanning device. The nonlinear response frequency is calculated based on a first driving frequency and a second driving frequency, where the first driving frequency refers to the driving frequency of the first actuator and the second driving frequency refers to the driving frequency of the second actuator.

Images