An imaging light engine and near-eye display device

Abstract

The utility model provides a kind of imaging light machine and near-eye display device, the imaging light machine includes: laser beam scanning light machine module, the laser beam scanning light machine module includes: laser light source and Lissajous scanning galvanometer;The laser light source is used to emit specified light beam to Lissajous scanning galvanometer, obtains the scanning light beam formed by Lissajous scanning galvanometer in any one fixed scanning line direction;The laser beam scanning light machine module has preset offset angle relative to imaging surface, so that the scanning line corresponding on the imaging surface of the scanning light beam is horizontally arranged.The imaging light machine disclosed in the utility model is set to only display the scanning light beam in one scanning line direction, overcomes the display artifact, brightness uneven display quality problem caused by scanning path, improves display image quality, and reduces the difficulty of display image processing.

Description

Technical Field

[0001] This utility model relates to the field of imaging control technology, and in particular to an imaging optical engine and a near-eye display device. Background Technology

[0002] Since near-eye display devices need to be worn on the head for extended periods, the optical engine, as a core component, must be large enough to increase the overall weight of the device and shift the center of gravity. Furthermore, the optical engine needs to be compactly integrated with components such as waveguides. If the size is too large, it will lead to complex optical path design and affect the display effect.

[0003] Lissajous scanning laser scanning (LBS) imaging has significant advantages in terms of size and power consumption, but the pseudo-random scanning path of Lissajous scanning can lead to display artifacts and uneven brightness in display quality.

[0004] Therefore, the existing technology needs further improvement. Utility Model Content

[0005] In view of the shortcomings of the prior art, the purpose of this utility model is to provide an imaging optical engine and a near-eye display device to overcome the defect of poor display quality in the laser scanning imaging process using Lissajous scanning galvanometers.

[0006] In a first aspect, an imaging optical engine has an imaging surface, comprising: a laser beam scanning optical engine module, the laser beam scanning optical engine module comprising: a laser source and a Lissajous scanning galvanometer;

[0007] The laser source is used to emit a specified beam of light that is incident on the Lissajous scanning galvanometer to obtain a scanning beam formed by the Lissajous scanning galvanometer in any fixed scanning line direction;

[0008] The laser beam scanning optical engine module has a preset offset angle relative to the imaging surface, so that the scanning lines of the scanning beam on the imaging surface are arranged in a horizontal direction.

[0009] Optionally, the Lissajous scanning galvanometer includes: a support frame, a central reflector fixed on the support frame, a driving electrode, a first vibration axis, and a second vibration axis; the driving electrode drives the central reflector to rotate around the first vibration axis and the second vibration axis; the axis of the first vibration axis and the axis of the second vibration axis are not orthogonal.

[0010] Optionally, the axis of the first vibration shaft and the axis of the second vibration shaft are not orthogonal in the following ways: the axis of the first vibration shaft is set to the vertical direction, and the axis of the second vibration shaft is set to have a target deviation angle from the horizontal direction; or, the axis of the second vibration shaft is set to the horizontal direction, and the axis of the first vibration shaft has a target deviation angle from the vertical direction.

[0011] Optionally, the scanning line direction of the Lissajous pattern includes: a first scanning direction class and a second scanning direction class; wherein, the first scanning direction class includes: the lower left to upper right direction and the upper right to lower left direction; the second scanning direction class includes: the upper left to lower right direction and the lower right to upper left direction;

[0012] The imaging optical engine also includes a light source controller;

[0013] The light source controller is used to control the output time of the laser beam output by the laser light source to obtain the specified beam; wherein the output time of the specified beam satisfies the condition that: when the scan line direction is in any fixed direction of the first scan direction class or the second scan direction class, and the scan line corresponding to the scan beam is located within a preset display area in the imaging plane.

[0014] Optionally, the axis of the first vibration axis is set to be vertical, the axis of the second vibration axis is set to have a target deviation angle with respect to the horizontal direction, and the scanning line direction of the Lissajous pattern is in the first scanning direction class. Then, the angle value of the preset deviation angle is equal to the angle value of the target deviation angle, and the angle direction of the preset deviation angle is opposite to that of the target deviation angle with respect to the horizontal direction.

[0015] Optionally, if the axis of the second vibration axis is set to the horizontal direction, and the axis of the first vibration axis has a target deviation angle between itself and the vertical direction, and the scanning line direction of the Lissajous pattern is in the second scanning direction class, then the angle value of the preset deviation angle is equal to the angle value of the target deviation angle, and the angle direction of the preset deviation angle is opposite to that of the target deviation angle relative to the vertical direction.

[0016] Optionally, it also includes a waveguide disposed in the output optical path of the scanning beam for guiding the scanning beam to the imaging surface for display; the plane in which the waveguide is located is parallel to the imaging surface.

[0017] Optionally, the edge of the preset display area is a rectangle, and the direction of the scan line is perpendicular to the boundary line of the rectangle.

[0018] Optionally, the direction of the scan line is perpendicular to the boundary line of the scan line.

[0019] Optionally, the formula for calculating the preset deviation angle is:

[0020]

[0021] Wherein, FOVx is the scanning optical rotation angle corresponding to the first vibration axis, FOVy is the scanning optical rotation angle corresponding to the second vibration axis, and K... x K is the scanning frequency of the first vibration axis. y The scanning frequency of the second vibration axis.

[0022] Secondly, this application provides a near-eye display device, which includes: the imaging optical engine.

[0023] Beneficial effects:

[0024] This invention provides an imaging optical engine and a near-eye display device. The imaging optical engine includes a laser beam scanning optical engine module, which comprises a laser source and a Lissajous scanning mirror. The laser source emits a specified beam that is incident on the Lissajous scanning mirror, resulting in a scanning beam formed by the Lissajous scanning mirror in any fixed scanning line direction. The laser beam scanning optical engine module has a preset offset angle relative to the imaging surface, so that the scanning lines of the scanning beam on the imaging surface are arranged horizontally. The imaging optical engine disclosed in this application, by displaying only the scanning beam in one scanning line direction, overcomes display quality problems such as display artifacts and uneven brightness caused by the scanning path, improves the display image quality, and reduces the difficulty of display image processing. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the imaging optical engine provided by this utility model;

[0026] Figure 2 This is a cross-sectional view of a Lissajous scanning galvanometer in the prior art;

[0027] Figure 3 This is a schematic diagram of a Lissajous scanning pattern in the prior art;

[0028] Figure 4 This is a cross-sectional view of the Lissajous scanning galvanometer provided by this utility model;

[0029] Figure 5 This is an exploded schematic diagram of the scanning pattern output by the Lissajous scanning galvanometer provided in this utility model;

[0030] Figure 6 This is a schematic diagram of the display architecture of the imaging optical engine provided by this utility model;

[0031] Figure 7This is a rotating diagram of the exploded view of the Lissajous scanned pattern provided by this utility model.

[0032] Figure 8 This is a cross-sectional view of the biaxially non-orthogonal Lissatogram scanning galvanometer in this embodiment;

[0033] Figure 9 This is a schematic diagram of the output scanning pattern when both axes output scan lines in this embodiment are not orthogonal in the Lissatogram scanning galvanometer;

[0034] Figure 10 This is a schematic diagram of the output scanning pattern in this embodiment when the scanning lines are output in only one direction and the biaxial axes in the Lissatogram scanning galvanometer are not orthogonal;

[0035] Figure 11 This is an exploded view of the output scanning pattern when the scanning line output in only one direction is in this embodiment and the biaxial parts of the Lissatogram scanning galvanometer are not orthogonal.

[0036] Figure 12 This is a schematic diagram showing the exploded view of the output scanning pattern after rotation when the scanning lines in this embodiment are output in only one direction and the two axes in the Lissatogram scanning galvanometer are not orthogonal.

[0037] Figure 13 This is a schematic diagram showing the overlap between the output scan line and the horizontal line when the two axes in the Lissatogram scanning galvanometer are not orthogonal, and only one direction of the scan line is output in this embodiment. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this utility model clearer and more explicit, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present utility model and are not intended to limit the present utility model.

[0039] Near-eye display devices are technological devices that project digital information into the field of vision of the human eye's retina through an optical system. They are mainly used in the fields of virtual reality (VR), augmented reality (AR), mixed reality (MR), and extended reality (XR). Their core principle is to simulate the binocular parallax mechanism of the human eye, using a micro-display screen and optical system to expand the field of view and achieve seamless integration of virtual and real content.

[0040] Because near-eye display devices are worn for extended periods, excessive weight can lead to user fatigue. The close-to-eye design necessitates a size that meets daily usage requirements, while also necessitating the compact integration of multiple components. An excessively large size increases the complexity of optical path design, thus imposing strict limitations on both weight and size for near-eye display devices.

[0041] Taking consumer-grade AR glasses as an example, they have stringent requirements on the size and power consumption of the display optical engine. Furthermore, most AR glasses applications involve information prompts or other functions displayed with a small number of pixels; therefore, active-matrix laser beam scanning, which eliminates the need for backlighting, offers a significant advantage in low power consumption. Additionally, Lissajous scanning, where both axes are in a resonant state, allows for a smaller driving mechanism, thus achieving a size advantage in AR displays. However, compared to raster scanning, the pseudo-random scanning path of Lissajous scanning leads to display quality issues such as artifacts, uneven brightness, and poor resolution. Moreover, the need for Lissajous transformation of the displayed image increases the difficulty of implementing image processing algorithms, thus limiting the widespread application of Lissajous scanning galvanometers in near-eye displays and related fields.

[0042] To overcome the aforementioned shortcomings, this invention provides an imaging optical engine and a near-eye display device. The imaging optical engine includes a laser beam scanning optical engine module, comprising a laser source and a Lissajous scanning mirror. The laser source emits a designated beam to the Lissajous scanning mirror, resulting in a scanning beam formed by the Lissajous scanning mirror along any fixed scanning line direction. By setting a preset offset angle between the laser beam scanning optical engine module and the imaging surface, the scanning lines of the scanning beam on the imaging surface are horizontal, thus achieving non-intersecting scanning line imaging. Since there is no need for Lissajous transformation of the displayed image when the scanning lines are non-intersecting, and the horizontal direction of the displayed pixels can be read sequentially, the difficulty of implementing the image display algorithm can be significantly reduced, and the image display quality can be improved.

[0043] The imaging optical engine and near-eye display device provided in this application will be described in further detail below with reference to the accompanying drawings.

[0044] First Embodiment Apparatus

[0045] This embodiment discloses an imaging optical engine, which has an imaging surface, such as... Figure 1 As shown, the imaging optical engine includes a laser beam scanning optical engine module 10. The laser beam scanning optical engine module 10 includes a laser source 101 and a Lissajous scanning galvanometer 102.

[0046] The laser source 101 is used to emit a specified beam of light that is incident on the Lissajous scanning mirror 102 to obtain a scanning beam of the Lissajous scanning mirror 102 in any fixed scanning line direction.

[0047] The laser beam scanning optical engine module 10 has a preset offset angle relative to the imaging surface, so that the scanning lines of the scanning beam on the imaging surface are arranged in a horizontal direction.

[0048] The Lissajous scanning galvanometer mentioned in this embodiment is an optical device capable of achieving fast and high-precision laser scanning. It is a two-dimensional MEMS galvanometer that can perform simple harmonic vibrations along two mutually perpendicular first and second vibration axes (such as the x-axis and y-axis). When a particle simultaneously participates in simple harmonic vibrations in both directions, and their frequency ratio is an integer ratio, the scanning trajectory of the reflected beam will form a stable and closed Lissajous pattern. By controlling the vibration frequency, amplitude, and initial phase of the first and second vibration axes, the shape and size of the Lissajous pattern can be adjusted, thereby achieving different scanning modes and coverage areas. Figure 2 As shown, the scanning direction of a Lissajous scanning galvanometer in the prior art is determined by the synthesis of vibrations in two mutually perpendicular directions, generally with the horizontal direction as the x-axis 201 and the vertical direction as the y-axis 202. The Lissajous scanning galvanometer undergoes simple harmonic oscillations on both the x-axis 201 and the y-axis 202, with both axes operating within their respective narrow frequency ranges, typically driven by high-frequency sine waves.

[0049] Furthermore, such as Figure 3 As shown, if a Lissajous scanning galvanometer scans in both the X and Y axes and the ratio of their vibration frequencies is an integer, it produces a closed Lissajous pattern. In this embodiment, the specified beam refers only to the scanning beam generated by the Lissajous scanning galvanometer in any fixed scanning line direction. For example, if the fixed scanning line direction is upper left to lower right or lower left to upper right, the scanning line trajectory is only... Figure 3 A portion shown, such as Figure 4 or Figure 5 As shown.

[0050] Combination Figure 1 and Figure 4 As shown, since the laser beam scanning optical-mechanical module 10 has no offset angle relative to the imaging surface, the scanning beam emitted from the laser beam scanning optical-mechanical module has a deflection angle between the scanning line direction and the horizontal direction on the imaging surface. In specific implementations, such as... Figure 6 As shown, if the laser beam scanning optical engine 10 is set to deviate from the imaging surface by a preset deflection angle, and this preset deflection angle is the same as the deflection angle between the scanning line direction and the horizontal direction, then the scanning lines can be arranged horizontally on the imaging surface. This allows the displayed image to be shown pixel by pixel along the scanning direction, line by line, without the need for... Figure 3 The scanning strategy requires cross-line display. In a specific embodiment, the light emitted from the laser beam scanning optical engine forms a light spot, and the central axis of the light spot is deflected at a preset angle to the central axis of the imaging surface.

[0051] Furthermore, if the first and second vibration axes of the Lissajous mirror are scanned at frequencies Kx and Ky, respectively, where the axis of the first vibration axis is in the X-axis direction and the axis of the second vibration axis is in the Y-axis direction; the optical rotation angle of the fast axis scan is FOV. x The optical rotation angle of slow-axis scanning is FOV. y Then, from geometric relations, we know Figure 4 The angle θ between the middle scan line and the horizontal direction satisfies the following relationship:

[0052]

[0053] Wherein, FOVx is the scanning optical rotation angle corresponding to the first vibration axis, FOVy is the scanning optical rotation angle corresponding to the second vibration axis, and K... x and K y These are the scanning frequencies of the first and second vibration axes, respectively.

[0054] To achieve a scan line parallel to the horizontal direction, the following is obtained: Figure 7 In the scanning pattern shown, this embodiment requires rotating the transmission direction of the scanning beam to a certain deviation angle. When the deviation angle between the scanning line and the x-axis is θ, if the output direction of the scanning beam output from the Lissajous scanning galvanometer needs to be opposite to the horizontal direction by an angle -θ, that is, when the deviation angle of the laser beam scanning optical engine module relative to the imaging plane is the same as the angle θ between the scanning line and the horizontal direction, but opposite in direction, then the scanning line at the center of the image is approximately parallel to the horizontal direction. Thus, when displaying the image, it can be displayed pixel by pixel along the scanning direction line by line, without needing to... Figure 3 The scanning strategy requires displaying across multiple lines.

[0055] Furthermore, in combination Figure 1 and Figure 6 As shown, the imaging optical engine is further provided with a waveguide 20. The plane of the waveguide 20 is parallel to the imaging plane. The laser beam scanning optical engine module 10 and the waveguide 20 are at a preset offset angle. The scanning beam output from the laser beam scanning optical engine module 10 enters the waveguide through the coupling region 210 in the waveguide 20, and after reflection within the waveguide, it is coupled out through the coupling region 212 to achieve image display. In a specific embodiment, the light emitted from the laser beam scanning optical engine forms a light spot, and there is a preset offset angle between the central axis of the light spot and the central axis of the coupling region of the waveguide.

[0056] In this embodiment, only one direction of the scan line is selected for display during imaging to achieve non-intersecting scanning line imaging. At the same time, the laser beam scanning optical engine module is set to have a preset deviation angle relative to the imaging surface, thereby rotating the scan line to an approximately horizontal direction for display. Since there is no need to perform Lissajous transformation on the displayed image and the displayed pixels are read in the horizontal direction in sequence, the difficulty of implementing the image display algorithm can be significantly reduced and the image display quality can be improved.

[0057] Second Embodiment Apparatus

[0058] In the first embodiment, when displaying using scan lines in one scanning direction, and simultaneously rotating the laser beam to scan the optical engine module with a preset offset angle relative to the imaging surface, the scan lines can be arranged horizontally, as shown in the following diagram. Figure 7 As shown. Because the scan lines are denser at the edges, which can easily lead to uneven pixel display, and the faster switching speed of the scanning galvanometer places higher demands on the laser's light modulation, and because most displays are rectangular, in practical applications only the central area is typically selected for image display. Figure 7 As shown, this results in a large amount of space around the perimeter being wasted and unable to be displayed effectively.

[0059] To overcome the drawback of the first embodiment where the area around the scanned pattern cannot be displayed and the actual usable display area is small, this embodiment also discloses another imaging optical engine. This imaging optical engine also includes a laser beam scanning optical engine module 10, which includes a laser source 101 and a Lissajous scanning galvanometer 102.

[0060] The laser source 101 emits a specified beam that is incident on the Lissajous scanning mirror 102, resulting in a scanning beam formed by the Lissajous scanning mirror 102 in any fixed scanning line direction. The laser beam scanning optical engine module has a preset offset angle relative to the imaging surface, so that the scanning line corresponding to the scanning beam is displayed horizontally within the imaging surface.

[0061] Furthermore, the Lissajous scanning galvanometer in this example includes: a support frame, a central reflector fixed on the support frame, a driving electrode, a first vibration axis, and a second vibration axis; the driving electrode drives the central reflector to rotate around the first vibration axis and the second vibration axis; the axis of the first vibration axis and the axis of the second vibration axis are not orthogonal.

[0062] Combination Figure 8The cross-sectional view of the scanning galvanometer shown illustrates that the axes of the first and second vibration axes are not orthogonal. For example, if the axis of the first vibration axis is set vertically at 100°, and the axis of the second vibration axis is set at 200° at a certain angle 30° away from the horizontal, and the Lissajous patterns under scanning frequencies of Kx and Ky are shown below. Figure 9 As shown, the scanning direction of the first vibration axis is the X-axis, and the scanning direction of the second vibration axis has a certain angle with the Y-axis; the optical rotation angle corresponding to the first vibration axis is FOVx, and the optical rotation angle corresponding to the second vibration axis is FOVy. The refresh rate of the image is GCD(Kx, Ky), where GCD() is the greatest common divisor function.

[0063] In this embodiment, the scanning line direction of the Lissajous pattern can be divided into two categories: the lower left-upper right direction (including scanning from the lower left to the upper right and scanning from the upper right to the lower left), such as... Figure 10 Decomposition in Figure 1 As shown, scan line 51 is perpendicular to scan boundary line 52; and the upper left-lower right direction (including two directions: scanning from the upper left to the lower right and scanning from the lower right to the upper left) is as follows. Figure 11 Decomposition in Figure 2 As shown. If only display Figure 10 or Figure 11 The corresponding scan lines do not intersect, which can significantly improve the quality of the displayed image.

[0064] Furthermore, the non-orthogonal arrangement of the axis of the first vibration axis and the axis of the second vibration axis includes: the axis of the first vibration axis is set in the vertical direction, and the axis of the second vibration axis is set to have a target deviation angle from the horizontal direction.

[0065] Alternatively, the axis of the second vibration axis is set to the horizontal direction, and the axis of the first vibration axis has a target deviation angle between it and the vertical direction.

[0066] Furthermore, the scanning line directions in the scanning pattern of the Lissajous mirror include: a first scanning direction class and a second scanning direction class; wherein, the first scanning direction class includes: the direction from the lower left to the upper right and the direction from the upper right to the lower left; the second scanning direction class includes: the direction from the upper left to the lower right and the direction from the lower right to the upper left.

[0067] In order to achieve the output of a specified beam from the laser source, the imaging optical engine also includes a light source controller, which controls the timing of the laser beam emitted by the laser source to obtain the specified beam.

[0068] Specifically, the light source controller is used to control the output time of the laser beam output by the laser light source to obtain the specified beam; wherein the output time of the specified beam satisfies the condition that: when the scan line direction is in any fixed direction of the first scan direction class or the second scan direction class, and the scan line corresponding to the scan beam is located within a preset display area in the imaging surface.

[0069] Because the Lissajous scanning mirror continuously scans in different directions, in order to obtain a scanning beam in a fixed scanning line direction, this embodiment controls the laser source to emit a beam to the Lissajous scanning mirror only when the Lissajous scanning mirror is scanning in a fixed scanning line direction, thereby achieving a scanning pattern in a fixed scanning line direction. That is, the specified beam in this embodiment is a non-continuous beam, emitted discontinuously in time. Furthermore, its emission time corresponds to the time when the scanning line direction is in either the first scanning direction class or the second scanning direction class, in a fixed direction.

[0070] Furthermore, in this embodiment, a preset deflection angle is also set between the laser beam scanning optical engine module and the imaging surface to achieve a preset deflection angle between the transmission direction of the scanning beam emitted by the laser beam scanning optical engine module and the imaging surface. Thus, the scanning lines corresponding to the scanning beam are arranged horizontally, and the scanning pattern is as follows: Figure 12 As shown, this allows the displayed image to be shown pixel by pixel along the scanning direction, line by line, without the need for... Figure 3 or Figure 9 The scanning strategy requires cross-line display. In one specific embodiment, the light emitted from the laser beam scanning optical engine forms a light spot, and the central axis of the light spot is offset from the central axis of the imaging surface by a preset angle.

[0071] Furthermore, the imaging optical engine of this embodiment also includes a waveguide, which is disposed in the output optical path of the scanning beam and is used to guide the scanning beam to the imaging surface for display; the plane in which the waveguide is located is parallel to the imaging surface. The scanning beam emitted by the laser beam scanning optical engine is input into the waveguide through the coupling region in the waveguide, and after reflection within the waveguide, it is coupled out through the coupling region to realize the display of the image.

[0072] In specific implementation, in order to achieve such Figure 12 If the scanning line is horizontal or approximately horizontal, then the angle between the laser beam scanning optomechanical module and the waveguide must be the same as the angle of deviation from the target, and the direction must be opposite to the horizontal or vertical direction.

[0073] Furthermore, when selecting scan lines, there are two different settings that can be used in practice:

[0074] In the first case, the axis of the first vibration axis is set to be vertical, and the axis of the second vibration axis is set to have a target deviation angle with respect to the horizontal direction. The scanning line direction of the Lissajous pattern is in the first scanning direction class. Then, the angle value of the preset deviation angle is equal to the angle value of the target deviation angle, and the angle direction of the preset deviation angle is opposite to that of the target deviation angle with respect to the horizontal direction.

[0075] In the first case, the axis of the second vibration axis is set to the horizontal direction, the axis of the first vibration axis has a target deviation angle between it and the vertical direction, and the scanning line direction of the Lissajous pattern is in the second scanning direction class. Then, the angle value of the preset deviation angle is equal to the angle value of the target deviation angle, and the angle direction of the preset deviation angle is opposite to that of the target deviation angle relative to the vertical direction.

[0076] Furthermore, considering that the display screen is generally rectangular, the area within the rectangular frame is taken as the actual display screen, and the final scan line distribution of the display area is as follows: Figure 13 As shown. Note that, due to the use of the biaxial non-orthogonal galvanometer provided in this embodiment, the side boundaries of the rotated scanning pattern are in the vertical direction, as shown. Figure 12 As shown, this eliminates the need to waste the horizontal optical scanning angle when capturing a rectangular frame for display, thus maximizing the use of display resources and avoiding waste.

[0077] Furthermore, most horizontal scan lines within the rectangular frame contain a complete half-sine scan cycle, and different scan lines have the same sinusoidal scan phase at the same X-axis coordinate, thus having similar X-axis scan speeds. This allows the same speed correction coefficient to be used at the same X-axis coordinate for different scan lines, thereby significantly reducing the difficulty of the Lissajous pattern display algorithm.

[0078] Furthermore, in specific implementation, such as Figure 10 As shown, the scan lines are perpendicular to the boundary lines of the scan lines. Because the scan lines are perpendicular to the boundary lines of the scan lines, the display area on the left and right sides can be utilized without wasting space when capturing the display screen, thus expanding the usable display screen.

[0079] The imaging optical engine disclosed in this embodiment divides Lissajous scan lines into two types: those in the lower left-upper right direction and those in the upper left-lower right direction. By reasonably setting the angle between the two vibration axes and the scanning angle, the scanning direction of one type of scan line in the center of the image can be perpendicular to the side of the parallelogram. During imaging, only this type of vertical side scan line is selected for display to achieve non-intersecting scanning line imaging. Furthermore, rotating the scan lines by a specific angle can achieve approximately horizontal display. Since there is no need to perform Lissajous transformation on the displayed image and the displayed pixels are read sequentially in the horizontal direction, the difficulty of implementing the image display algorithm can be significantly reduced, and the image display quality can be improved.

[0080] Third Embodiment Device

[0081] Furthermore, this application discloses a near-eye display device, comprising: the imaging optical engine disclosed in the first or second embodiment described above. This near-eye display device can be consumer-grade AR glasses or other near-eye display devices.

[0082] Since the imaging optical engine provided in this embodiment can achieve higher resolution display images and can use simpler image display algorithms to adjust and process images, the near-eye display device provided in this embodiment has higher display image quality, reduces technical implementation costs, and broadens the application scope of Lissajous scanning galvanometers in near-eye display technology.

[0083] This invention provides an imaging optical engine and a near-eye display device. The imaging optical engine includes a laser beam scanning optical engine module, which comprises a laser source and a Lissajous scanning mirror. The laser source emits a specified beam that is incident on the Lissajous scanning mirror, resulting in a scanning beam generated by the Lissajous scanning mirror in any fixed direction. The laser beam scanning optical engine module has a preset offset angle relative to the imaging surface, so that the scanning line corresponding to the scanning beam is displayed horizontally. The imaging optical engine disclosed in this application, by displaying only the scanning beam in one scanning line direction, overcomes display quality problems such as display artifacts and uneven brightness caused by the scanning path, improves the display image quality, and reduces the difficulty of display image processing.

[0084] Other embodiments of the present invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein.

[0085] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0086] It is understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present application.

Claims

1. An imaging optical engine, wherein the imaging optical engine has an imaging surface, characterized in that, include: A laser beam scanning optomechanical module, comprising: a laser source and a Lissajous scanning galvanometer; The laser source is used to emit a specified beam of light that is incident on the Lissajous scanning galvanometer to obtain a scanning beam formed by the Lissajous scanning galvanometer in any fixed scanning line direction; The laser beam scanning optical engine module has a preset offset angle relative to the imaging surface, so that the scanning lines of the scanning beam on the imaging surface are arranged in a horizontal direction.

2. The imaging optical engine according to claim 1, characterized in that, The Lissajous scanning galvanometer includes: a support frame, a central reflector fixed on the support frame, a driving electrode, a first vibration axis, and a second vibration axis; the driving electrode drives the central reflector to rotate around the first vibration axis and the second vibration axis; the axis of the first vibration axis and the axis of the second vibration axis are not orthogonal.

3. The imaging optical engine according to claim 2, characterized in that, The way in which the axis of the first vibration shaft and the axis of the second vibration shaft are not orthogonal is as follows: the axis of the first vibration shaft is set to the vertical direction, and the axis of the second vibration shaft is set to have a target deviation angle from the horizontal direction; or, the axis of the second vibration shaft is set to the horizontal direction, and the axis of the first vibration shaft has a target deviation angle from the vertical direction.

4. The imaging optical engine according to claim 3, characterized in that, The scan line directions include: a first scan direction class and a second scan direction class; wherein, the first scan direction class includes: the direction from the lower left to the upper right and the direction from the upper right to the lower left; the second scan direction class includes: the direction from the upper left to the lower right and the direction from the lower right to the upper left; The imaging optical engine also includes a light source controller; The light source controller is used to control the output time of the laser beam output by the laser light source to obtain the specified beam; wherein the output time of the specified beam satisfies the condition that: when the scan line direction is in any fixed direction of the first scan direction class or the second scan direction class, and the scan line corresponding to the scan beam is located within a preset display area in the imaging plane.

5. The imaging optical engine according to claim 4, characterized in that, The axis of the first vibration axis is set to be vertical, and the axis of the second vibration axis is set to have a target deviation angle with respect to the horizontal direction. The direction of the scan line is in the first scan direction class. Then, the angle value of the preset deviation angle is equal to the angle value of the target deviation angle, and the angle direction of the preset deviation angle is opposite to that of the target deviation angle with respect to the horizontal direction.

6. The imaging optical engine according to claim 4, characterized in that, The axis of the second vibration axis is set to the horizontal direction, the axis of the first vibration axis has a target deviation angle between it and the vertical direction, and the scanning line direction is in the second scanning direction class. Then the angle value of the preset deviation angle is equal to the angle value of the target deviation angle, and the angle direction of the preset deviation angle is opposite to that of the target deviation angle relative to the vertical direction.

7. The imaging optical engine according to any one of claims 1-6, characterized in that, It also includes a waveguide, which is disposed in the output optical path of the scanning beam and is used to guide the scanning beam to the imaging surface for display; the plane in which the waveguide is located is parallel to the imaging surface.

8. The imaging optical engine according to any one of claims 2-6, characterized in that, The direction of the scan line is perpendicular to the boundary line of the scan line.

9. The imaging optical engine according to claim 6, characterized in that, The formula for calculating the preset deviation angle is: ； Wherein, FOVx is the scanning optical rotation angle corresponding to the first vibration axis, FOVy is the scanning optical rotation angle corresponding to the second vibration axis, and K... x K is the scanning frequency of the first vibration axis. y The scanning frequency of the second vibration axis.

10. A near-eye display device, characterized in that, include: The imaging optical engine as described in any one of claims 1 to 8.

Images