Scanning track detection device and scanning track detection method

Abstract

The invention discloses a scanning track detection device and a scanning track detection method. The scanning track detection device comprises a scanning device, one or more sensors and a processor, the one or more sensors are used for detecting the moment when a light spot corresponding to a test image output by the scanning device scans the sensor; and the processor is used for determining the scanning track characteristics of the scanning device according to the moment when the light spot scans the one or more sensors, so that the problems that in the prior art, a high-speed response photoelectric sensor and a high-speed signal processing circuit are needed for directly sampling a complete scanning track by adopting a sensor scheme, and the sampling precision is low are solved. The technical problems that the implementation difficulty is large and the cost is very high are solved, and the technical effect that scanning track detection can be achieved through a small number of low-cost photoelectric sensors is achieved.

Description

Technical Field

[0001] The present invention relates to the field of projection display, and in particular to a scanning trajectory detection device and a scanning trajectory detection method. Background Art

[0002] In AR (Augmented Reality) display technology, MEMS galvanometers or FSD (fiber scanning display) can be used to achieve scanning display imaging. Scanning display requires closed-loop driving to ensure image stability. To achieve closed-loop driving, it is necessary to accurately detect the scanning trajectory.

[0003] Due to the strict requirements for the appearance, size, and volume of AR glasses, the feedback device for detecting the scanning trajectory needs to be realized without damaging the appearance of the glasses. In the prior art, various sensors are usually used to detect the trajectory to achieve trajectory correction.

[0004] Adopting the sensor solution to directly sample the complete scanning trajectory requires a high-speed response optoelectronic sensor and a high-speed signal processing circuit, which is difficult to implement and has a high cost. Summary of the Invention

[0005] The purpose of the present invention is to provide a scanning trajectory detection device and a scanning trajectory detection method, which can achieve scanning trajectory detection with a small number of low-cost optoelectronic sensors.

[0006] To achieve the above object of the invention, in the first aspect of the embodiments of the present invention, a scanning trajectory detection device is provided. The scanning trajectory detection device includes a scanning device, one or more sensors, and a processor;

[0007] The one or more sensors are used to detect the moment when the light spot corresponding to the test image output by the scanning device scans across the sensors;

[0008] The processor is used to determine the scanning trajectory characteristics of the scanning device according to the moment when the light spot scans across the one or more sensors.

[0009] Optionally, the sensor is a single-point optoelectronic sensor.

[0010] Optionally, an optical structure is provided between the scanning device and the sensor for focusing the light emitted by the scanning device on the photosensitive surface of the sensor.

[0011] Optionally, the optical structure includes a lens or a micropore.

[0012] Optionally, the sensor is configured to record the signal intensity values detected by the sensor during the scanning process to obtain a signal intensity curve; and use the moment corresponding to the center position of the curve peak of the signal intensity curve as the moment when the light spot scans across the sensor.

[0013] Optionally, the signal intensity value detected by the sensor is the signal intensity integral value of one or more frames of test images.

[0014] Optionally, the test image is a vertical line; during the scanning process, adjust the display delay or driving phase in the horizontal direction, and record the horizontal delay when the light spot corresponding to the test image scans across the sensor.

[0015] Optionally, the test image is a horizontal line; during the scanning process, adjust the display delay or driving phase in the vertical direction, and record the vertical delay when the light spot corresponding to the test image scans across the sensor.

[0016] Optionally, the processor is configured to calculate the image horizontal delay according to the horizontal delay when the light spot scans across the sensor and the relative position between the sensor and the test image.

[0017] Optionally, the processor is configured to calculate the image vertical delay according to the vertical delay when the light spot scans across the sensor and the relative position between the sensor and the test image.

[0018] Optionally, the scanning trajectory detection device includes two sensors located at different positions at the same horizontal height; the test image is a single-line horizontal line;

[0019] If the delay values when the test image scans across the two sensors are the same, it is determined that the scanning trajectory is a horizontal straight line; if the delay values when the test image scans across the two sensors are different, it is determined that the scanning trajectory is not a horizontal straight line.

[0020] Optionally, the processor is configured to record the driving voltage of the scanning device corresponding to the moment when the light spot scans across the sensor, and determine the swing amplitude of the scanning trajectory at the driving voltage as the target swing amplitude, where the target swing amplitude is calculated based on the position of the sensor.

[0021] A second aspect of the embodiments of the present invention provides a scanning trajectory detection method, which is applied to a scanning trajectory detection device, and the scanning trajectory detection device includes a scanning device and one or more sensors; the method includes:

[0022] Detecting, by the one or more sensors, the moment when the light spot corresponding to the test image output by the scanning device scans across the sensor;

[0023] Determine the scanning trajectory characteristics of the scanning device according to the moment when the light spot scans across the one or more sensors.

[0024] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0025] In the solution of the embodiment of the present invention, the scanning trajectory detection device includes a scanning device, one or more sensors, and a processor; the moment when the light spot corresponding to the test image output by the scanning device scans across the sensors is detected by the sensors; then, the processor determines the scanning trajectory characteristics of the scanning device according to the moment when the light spot scans across the one or more sensors, thereby alleviating the technical problems existing in the prior art that a high-speed response optoelectronic sensor and a high-speed signal processing circuit are required to directly sample the complete scanning trajectory by using a sensor solution, which is difficult to implement and has a high cost, and realizing the technical effect that the scanning trajectory detection can be achieved by using a small number of low-cost optoelectronic sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts:

[0027] Figure 1 It is a schematic structural diagram of the scanning trajectory detection device provided by the embodiment of the present invention;

[0028] Figure 2A It is a schematic diagram of the center position of the light spot provided by the embodiment of the present invention;

[0029] Figure 2B It is a schematic diagram of the signal intensity curve of the sensor provided by the embodiment of the present invention;

[0030] Figure 3A It is an energy distribution diagram of a clearly imaged light spot provided by the embodiment of the present invention;

[0031] Figure 3B It is an energy distribution diagram of a non-clearly focused light spot provided by the embodiment of the present invention;

[0032] Figure 4 It is a schematic diagram of the test image and the moving direction of the light spot provided by the embodiment of the present invention;

[0033] Figures 5A - 5C It is a schematic diagram of the relative displacement between the display content and the sensor provided by the embodiment of the present invention;

[0034] Figure 6 Schematic diagram of the signal intensity curve of another sensor provided by an embodiment of the present invention;

[0035] Figure 7 Schematic diagram of the scanning trajectory and the sensor provided by an embodiment of the present invention;

[0036] Figure 8 Schematic diagram of the signal intensity curve of yet another sensor provided by an embodiment of the present invention;

[0037] Figure 9 Schematic diagram of setting two sensors A and B provided by an embodiment of the present invention;

[0038] Figure 10 Schematic diagram of the sensor located at the edge of the scanning area provided by an embodiment of the present invention;

[0039] Figure 11A and Figure 11B Schematic diagram of the sensor located outside the image provided by an embodiment of the present invention;

[0040] Figure 12 Schematic diagram of the moving direction of the test pattern provided by an embodiment of the present invention;

[0041] Figure 13 Schematic diagram of setting two sensors A and B at the same horizontal height provided by an embodiment of the present invention. Detailed implementation manners

[0042] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0043] In the embodiments of the present invention, the scanning device may be a MEMS galvanometer or an optical fiber scanning display device, etc., and the corresponding scanning modes may be raster, Lissajous, spiral, etc. In the following embodiments, the optical fiber scanning display device is used as the scanning device and the raster scanning mode is taken as an example for description.

[0044] Please refer to Figure 1 , Figure 1 Schematic diagram of the structure of the scanning trajectory detection device provided by an embodiment of the present invention; The opto-mechanical structure of the scanning trajectory detection device includes a scanning device A, a lens B, a sensor C, and a waveguide lens D. Among them, part of the light output by the scanning device A is transmitted to the human eye through the waveguide lens D, and part of the light passes through the waveguide lens D and enters the sensor C to realize trajectory detection.

[0045] Sensor C can be a single-point optical sensor, which converts the light intensity information irradiated on the photosensitive surface of the sensor into an electrical signal. When the light spot output by the scanning device A sweeps across the optical sensor, the light intensity distribution of the light spot center sweeping across the sensor area can be recorded by the sensor. As Figure 2A and Figure 2B shown, the center position of the signal intensity curve peak is the center position of the light spot. Further, the moment corresponding to the center position of the curve peak of the signal intensity curve is used as the moment when the light spot sweeps across the sensor.

[0046] In the projection image display, the center of the light spot energy is used as the geometric center of the light spot. When the light spot is not well focused and imaged, the position of the center of its energy distribution remains unchanged compared with the position when it is clearly focused. As Figure 3A shown, it is the light spot energy distribution diagram with clear imaging, and as Figure 3B shown, it is the light spot energy distribution diagram with non-clear focus. Therefore, in this solution, without the need for an optical structure to achieve good focusing imaging conditions, the light change center can still be determined through the energy distribution curve detected by the sensor.

[0047] In another possible implementation, between the scanning device A and the sensor C, specific optical structures such as lenses and micropores can also be used to optically focus the light emitted by the scanner on the photosensitive surface of the sensor to achieve the detection of the light energy distribution.

[0048] In the embodiments of the present invention, the number of sensors can be one or more. When the number of sensors is multiple, different sensors respectively detect the moments when the light spots corresponding to the test images sweep across each sensor.

[0049] In the embodiments of the present invention, the scanning trajectory features include one or more of image delay, scanning trajectory swing amplitude, and horizontal straight line. Among them, the image delay includes horizontal delay and vertical delay. Different test images can be used when detecting different scanning trajectory features, which will be described in the subsequent embodiments.

[0050] In the embodiments of the present invention, for raster scanning, the scanning device includes a fast axis and a slow axis. The fast axis scans along the horizontal direction (x direction), and the slow axis scans along the vertical direction (y direction).

[0051] As Figure 4 shown, when the test image includes a straight line, the position of the line center can be determined by detecting the signal intensity curve through the sensor. In order to eliminate the alignment error between the light spot and the sensor, when detecting the light spot, the test image can be designed as a line perpendicular to the moving direction of the light spot. As Figure 4 shown, the test image is a vertical line, and the light spot moves along the horizontal direction.

[0052] During the scanning process, vertical line displacement can be achieved by adjusting the driving phase delay or the display delay. The sensor position is calibrated in advance, and the sensor position can be accurately known. Then, through the scanning method, the driving phase delay or the display delay when the center of the vertical line sweeps through the center position of the sensor is determined.

[0053] When the test image is displayed as a vertical line, by adjusting the display delay in the x direction or the driving phase delay of the fast axis for scanning, the sensor delay value when the center position of the vertical line sweeps through the center position of the sensor can be determined.

[0054] When the test image is displayed as a horizontal line, by adjusting the display delay in the y direction or the driving phase delay of the slow axis for scanning, the sensor delay value when the center position of the horizontal line sweeps through the center position of the sensor can be determined.

[0055] To reduce system requirements, when detecting the horizontal delay, it is not necessary to detect the signal intensity of a single fast-axis scanning period. The integral value of one or more frame displays can be calculated. Therefore, the cut-off frequency of the sensor low-pass filter can be much lower than the fast-axis scanning frequency and higher than the speed of adjusting the driving phase and the display delay.

[0056] Through the above method, the measurement and calibration of the scanning display trajectory can be achieved. Next, the trajectory detection method in the embodiments of the present invention will be described in combination with specific embodiments.

[0057] Embodiment 1

[0058] Image delay detection. In the scanning display, the display content needs to modulate the light source according to the scanning trajectory in time sequence to complete the image display. If the display content of the fast axis is not synchronized with the fast-axis trajectory, the display content will shift left and right. In the scanning display, due to the phase difference between the mechanical vibration phase of the fast axis and the driving signal phase, and the phase difference will change with the change of the system vibration response characteristics. To compensate for the phase difference, it is necessary to adjust the driving phase or the display drive to increase a display delay, and the two have the same effect on the image display. In practical applications, the fast axis usually requires an additional correction driving signal in the y direction to ensure that the scanning trajectory is closed and not an ellipse. If the driving phase is adjusted, the correction phase needs to be adjusted synchronously to ensure that the fast-axis trajectory is closed.

[0059] As Figures 5A - 5C shown, by adjusting the display delay or the driving phase of the fast axis, relative displacement between the display content and the sensor can be achieved, so that the sensor can detect the image of this line.

[0060] During the scanning process, by recording the sensor signal intensity value in real time, a curve can be obtained, as Figure 6As shown, the delay t1 corresponding to the center position of the curve peak is the display delay or driving phase when the center of the vertical line in the test image is aligned with the center of the sensor. Since the position of the sensor is fixed and the relative position of the sensor in the image is known, the correct image delay value can be derived according to the method in the embodiment of the present invention. Here, the image delay refers to the horizontal delay.

[0061] In the embodiment of the present invention, for the convenience of description, as Figure 7 shown, the starting position at the leftmost side of the scanning trajectory is defined as the 0-phase position of the fast-axis vibration trajectory, as shown in the following figure. The 0-pi segment trajectory is for odd rows, and the pi-2pi segment trajectory is for even rows.

[0062] In the embodiment of the present invention, an example is given where the sensor is installed at the exact center of the image display position.

[0063] As Figure 7 shown, the fast axis sweeps across the sensor at pi / 4 and pi*3 / 4 respectively. Design an original image with a vertical line displayed at the exact center of the image and only displayed in odd rows. That is, the vertical line is displayed at the point of phase pi / 4. Adjust the phase delay of the driving signal (if the correction voltage is not 0, the phase of the correction voltage needs to be adjusted synchronously) so that the vertical line sweeps across the sensor, and the curve as Figure 8 shown is obtained. Then, calculate the center position of the curve to obtain the t1 value. It can be concluded that when the fast-axis driving phase is t1, the pi / 4 position of the scanning vibration trajectory coincides with the sensor, the image is displayed normally, and the content displayed on the fast axis is synchronized with the fast-axis trajectory.

[0064] In the above scheme, it is also possible not to adjust the phase delay of the driving voltage, and it is also feasible to adjust the display delay.

[0065] In the embodiment of the present invention, the sensor may not be centered (i.e., the sensor part is not installed at the exact center of the image display position), and the image may also be displayed in even rows. It can be corrected according to the position relationship between the vertical line position of the test image and the sensor position. And even if the position of the sensor is unknown, the phase calibration can be achieved according to the following method.

[0066] First, during factory calibration:

[0067] Adjust the image delay correctly so that the odd and even row images coincide; record the current image delay d1;

[0068] Steppingly adjust the delay value within the range of d1-s and d1+s to make the light spot output by the scanning device sweep across the sensor; in the embodiment of the present invention, the value of s is related to the specific characteristics of the scanning device, such as characteristics like swing amplitude, light spot size, and consistency. The value of s needs to ensure that the light spot completely sweeps across the sensor, that is, s>d1+w1, where d1 is the light spot diameter and w1 is the width of the sensor photosensitive surface.

[0069] Record the sensor signal values, perform filtering, curve fitting and other methods to eliminate noise and reduce measurement errors;

[0070] Find out the delay value d2 corresponding to the central axis of the curve peak;

[0071] Record Δd = d2 - d1 to complete the factory calibration.

[0072] When the scanner delay needs to be corrected:

[0073] Steplessly adjust the delay value within the range of d1 - s and d1 + s to make the light spot sweep across the sensor;

[0074] Record the sensor signal values, and eliminate noise and reduce measurement errors through filtering, curve fitting and other methods;

[0075] Find out the delay value d2' corresponding to the central axis of the curve peak;

[0076] Calculate d1' = d2' - Δd; where d1' is the drive delay corresponding to the coincidence of the current odd and even row images.

[0077] In the above solution, when setting the drive delay to scan within the range of 0 - 2pi, two peaks t1 and t2 will be obtained, and t1 - t2 = T / 2, where T is a fast axis scanning period. Among them, one peak is the delay when the light spot sweeps across the sensor at the odd frame position, and the other is the delay when the even frame position scans the sensor. Since a single sensor cannot determine the translation direction of the image during the process of adjusting the delay, if the image is flipped left and right, the single sensor cannot distinguish whether the image scanned across the sensor is an odd frame image or an even frame image. In the embodiments of the present invention, the following two implementation manners can also be used to determine whether the image is flipped left and right.

[0078] In a possible implementation manner, as Figure 9 shown, an additional sensor can be added, and by comparing the central positions of the curve peaks of the signal intensity curves detected by the two sensors, it is determined whether the image is flipped left and right.

[0079] In Figure 9 , assume that the left sensor is A, the central sensor is B, and the phase difference between AB is dP ab , after correcting the drive phase delay through B, set the drive delay to scan from the current value to t1 - 2*dP ab / 2pi*T x within the range, T x is the fast axis scanning period. If the sensor A detects the light spot, it indicates that the image is displayed normally and has not been flipped left and right. If the sensor A does not detect the light spot, it indicates that the phase difference between the current trajectory and the expected trajectory is pi, and the displayed image is flipped left and right. Then correct the current drive delay by pi, and the corrected delay is t1' = t1 + Tx / 2.

[0080] In another possible implementation, before detecting the driving phase delay using the above method, an external device is used for calibration to determine the initial driving delay value t int . During the normal use of the product, due to factors such as device aging and external conditions, the phase drift amount of the fast-axis vibration response generally does not exceed T x / 2. Therefore, it can be approximately considered that t int -t < T x . Therefore, the values that make t int -t greater than T x can be directly eliminated.

[0081] In the embodiments of the present invention, left and right offsets of the image center position will cause measurement errors, and the following method can be used to eliminate them. If t 1 -t 2 = T / 2 (T is a fast-axis scanning period), it indicates that the image center has no offset. If t 1 -t 2 ≠ T / 2, it indicates that the center position is offset. t 1 -t 2 - T / 2 is the center offset amount.

[0082] Embodiment 2

[0083] Amplitude detection. As shown in Figure 10 , at the edge of the scanning area, that is, at a non-center position, a sensor is placed, and the closer to the edge, the higher the accuracy. The target amplitude is calculated based on the position of the sensor. When the light spot corresponding to the test image scans over the sensor, it means that the amplitude reaches the target amplitude.

[0084] In the embodiments of the present invention, after the phase delay correction, amplitude detection is performed. The specific implementation of the phase delay correction can refer to the description in Embodiment 1. A vertical line is displayed at the phase position corresponding to the sensor. The fast-axis amplitude gradually increases from 0. As shown in Figure 10 , at the driving voltage corresponding to the center of the curve peak of the signal intensity curve detected by the sensor, the scanning trajectory amplitude is the target amplitude.

[0085] In the embodiments of the present invention, the offset of the image center position will cause amplitude detection errors, and an additional sensor can be added to eliminate the errors.

[0086] In a possible implementation, a sensor can be placed at the center position, and then, according to the method in the phase detection in Embodiment 1, the center offset is eliminated;

[0087] In the second possible implementation, a sensor can be added at a non-central position. The driving voltages required when the swing amplitude reaches the rated swing amplitude are measured respectively according to the swing amplitude detection method. If the calculated driving voltages are different twice, it indicates that the image center position has shifted.

[0088] In the third possible implementation, when adjusting the fast-axis driving phase, the sensor is located on the outer left or right side of the image, as Figure 11A and Figure 11B shown. Ensure that the sensor is outside the image and can receive the light intensity signal. The test image is a vertical line or a rectangular area of the same width. Adjust the delay. When the vertical line is at one edge of the sensor, the signal intensity received by the sensor is the largest. Within a certain range, the detection result is not affected by the relative position between the sensor and the image, nor by the fast-axis swing amplitude and the slow-axis swing amplitude. Therefore, this method has stronger parameter redundancy and directly completes the correction of phase delay using a single sensor.

[0089] In the specific implementation process, as Figure 12 shown, set the test image as a vertical line or a rectangular area. At the factory, adjust the image delay correctly so that the odd and even line images coincide, and record the current image delay d1. Then, adjust the delay in one direction so that the image moves to the sensor side edge and then turns back. Record the sensor signal value, and use methods such as filtering and curve fitting to eliminate noise and reduce measurement errors. Find the delay value d2 corresponding to the center axis of the curve peak, and record Δd = d2 - d1. The factory calibration is completed.

[0090] In the subsequent use process, when the scanner delay needs to be corrected, within the range of d1 - s and d1 + s, adjust the delay value in one direction so that the image moves to the sensor side edge and then turns back. Record the sensor signal value, and use methods such as filtering and curve fitting to eliminate noise and reduce measurement errors. Find the delay value d2' corresponding to the center axis of the curve peak. Calculate d1' = d2' - Δd, where d1' is the driving delay corresponding to the coincidence of the current odd and even line images.

[0091] Embodiment 3

[0092] Horizontal straight line detection. For raster scanning, when the vibration amplitude of the optical fiber in the resonance region is relatively large, the movement trajectory of the fast axis of the optical fiber scanner is no longer an ideal horizontal straight line, but an inclined straight line. Moreover, affected by driving performance, voltage fluctuations, etc., the movement trajectory of the fast axis will become an ellipse.

[0093] As Figure 13 shown, at the same horizontal height, two sensors A and B are set at different positions. B is located at the horizontal center, and A is close to the horizontal edge.

[0094] Set the test image as a single-line odd-frame horizontal line image, and use the line center detection method described in the foregoing embodiments to detect the delay value t when the horizontal line sweeps across the centers of sensor A and sensor B. as and t bs . Calculate dt s = t as - t bs . If dt s = 0, it indicates that the actual display trajectory of the horizontal line is a horizontal straight line. If dt s is not 0, then set the test image as an even-line odd-frame horizontal line image, and use the line center detection method described in the foregoing embodiments to detect the delay value t ad and t bd . Calculate dt d = t ad - t bd .

[0095] If dt d = dt s , it indicates that the actual display trajectory is an inclined straight line.

[0096] If dt d != dt s , it indicates that the actual display trajectory is an ellipse.

[0097] When the actual display trajectory is not a horizontal straight line, the correction voltage can be adjusted to make dt s = 0, so that the fast-axis scanning trajectory can be inclined and the ellipse problem can be corrected to a horizontal closed straight line.

[0098] All features disclosed in this specification, or all steps in the disclosed methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

[0099] Any feature disclosed in this specification (including any additional claims, abstract, and drawings), unless specifically stated, can be replaced by other equivalent or similar-purpose alternative features. That is, unless specifically stated, each feature is only an example of a series of equivalent or similar features.

[0100] The present invention is not limited to the foregoing specific embodiments. The present invention extends to any new feature or any new combination disclosed in this specification, as well as any new combination of steps of any new method or process disclosed.

Claims

1. A scanning trajectory detection device, characterized in that, the scanning trajectory detection device includes a scanning device, one or more sensors, and a processor; the one or more sensors are used to detect the moment when the light spot corresponding to the test image output by the scanning device scans across the sensors; the processor is used to determine the scanning trajectory characteristics of the scanning device according to the moment when the light spot scans across the one or more sensors.

2. The device according to claim 1, characterized in that, the sensor is a single-point light sensor.

3. The device according to claim 1, characterized in that, an optical structure is arranged between the scanning device and the sensor, and is used to focus the light emitted by the scanning device on the photosensitive surface of the sensor.

4. The device according to claim 3, characterized in that, the optical structure includes a lens or a micropore.

5. The device according to claim 1, characterized in that, the sensor is used to record the signal intensity value detected by the sensor during the scanning process to obtain a signal intensity curve; and use the moment corresponding to the center position of the curve peak of the signal intensity curve as the moment when the light spot scans across the sensor.

6. The device according to claim 5, characterized in that, the signal intensity value detected by the sensor is the signal intensity integral value of one frame or multiple frames of test images.

7. The device according to claim 1, characterized in that, the test image is a vertical line; during the scanning process, adjust the display delay or driving phase in the horizontal direction, and record the horizontal delay when the light spot corresponding to the test image scans across the sensor.

8. The device according to claim 1, characterized in that, the test image is a horizontal line; during the scanning process, adjust the display delay or driving phase in the vertical direction, and record the vertical delay when the light spot corresponding to the test image scans across the sensor.

9. The device according to claim 7, characterized in that, the processor is used to calculate the image horizontal delay according to the horizontal delay when the light spot scans across the sensor and the relative position between the sensor and the test image.

10. The device according to claim 8, characterized in that, the processor is used to calculate the image vertical delay according to the vertical delay when the light spot scans across the sensor and the relative position between the sensor and the test image.

11. The device according to claim 1, characterized in that, the scanning trajectory detection device includes two sensors at different positions at the same horizontal height; the test image is a single-line horizontal line; if the delay values when the test image scans across the two sensors are the same, it is determined that the scanning trajectory is a horizontal straight line; if the delay values when the test image scans across the two sensors are different, it is determined that the scanning trajectory is not a horizontal straight line.

12. The device according to claim 1, characterized in that, the processor is used to record the driving voltage of the scanning device corresponding to the moment when the light spot scans across the sensor, and determine the scanning trajectory swing amplitude at the driving voltage as the target swing amplitude, and the target swing amplitude is calculated based on the position of the sensor.

13. A scanning trajectory detection method, which is applied to a scanning trajectory detection device, characterized in that, the scanning trajectory detection device includes a scanning device and one or more sensors; the method includes: detecting, by the one or more sensors, the moments when the light spots corresponding to the test images output by the scanning device scan across the sensors; determining the scanning trajectory characteristics of the scanning device according to the moments when the light spots scan across the one or more sensors.

Images