Multi-level projection with laser beam scanning into augmented reality displays

Abstract

An image projection system (100; 200), comprising: a first transmitter (212d) configured to generate first light rays corresponding to a first projection plane and to send the first light rays along a first transmission path; a first collimation lens (213d) arranged on the first transmission path, the first collimation lens being configured to receive the first light rays and to produce first collimated light rays to be projected onto an eye to reproduce a first projection image that is perceived on the first projection plane; a second transmitter (212i) configured to generate second light beams corresponding to a second projection plane different from the first projection plane and to transmit the second light beams along a second transmission path; a second collimating lens (213i) arranged on the second transmitting path, the second collimating lens being configured to receive the second light rays and to produce second collimated light rays to be projected onto the eye to reproduce a second projection image that is perceived on the second projection plane; a first beam combiner (214) arranged at an intersection of the first transmission path and the second transmission path, wherein the first beam combiner is configured to transmit the first collimated light beams and the second collimated light beams on a combined transmission path; and a scanner (225) arranged on the combined transmission path, the scanner being configured to receive the first collimated light beams and the second collimated light beams and to direct the first collimated light beams and the second collimated light beams according to a scanning pattern to reproduce the first projection image and the second projection image to the eye.

Description

BACKGROUND

[0001] Augmented Reality (AR) is a technology that enhances physical environments on a mobile device screen by overlaying them with digital content. It adds digital elements to a live view. For example, a captured section of an environment is enhanced with digital information superimposed on it. Digital content is thus placed over the captured section of the environment to provide a user with additional visual information. The digital content can be displayed on a transparent substrate or display, such as with smart glasses, smart contact lenses, head-up displays (HUDs), and head-mounted displays (HMDs), or projected directly onto a user's retina, as is the case with virtual retinal displays.

[0002] Virtual reality (VR) is a technology in which a user's real-world environment is completely replaced by a computer-generated virtual environment. This provides the user with a fully digital environment. In particular, the computer-generated stereoscopic images completely surround the user. A VR headset, which provides a 360-degree view, can be used in a simulated VR environment.

[0003] A mixed-reality (MR) experience combines elements of AR and VR in such a way that real and digital objects interact. Here, a real environment is blended with a virtual one.

[0004] These technologies, along with others that enhance a user's senses, can be referred to as augmented reality (XR) technologies. One existing problem with XR technologies arises when there is a vergence-accommodation conflict. This type of conflict occurs when, with stereoscopic projection displays, the eye's accommodation does not match the eye's vergence. This can cause the user to feel ill or nauseous. Another problem with XR technologies is called focal rivalry, where a virtual object competes with a real-world object for focal attention. Focal rivalry can cause an object to appear blurry and, in turn, can lead to eye strain and fatigue for the user, as the eyes must frequently refocus.To avoid this, seamless virtual object insertion should occur at a correct virtual distance to prevent the eye from refocusing when switching between real and virtual objects. However, current systems are limited in that they require a bulky projection lens and are subject to time-division multiplexing, meaning they cannot project multiple objects simultaneously at different virtual distances or multiple virtual planes (i.e., only one virtual distance can be projected at a time).

[0005] DE 10 2019 107 659 A1 describes a display system for vehicles, typically a head-up display, that projects a virtual image onto a projection plane, such as the road surface. To correct distortions of the virtual image on an inclined projection plane, e.g., on inclines or declines, a movable screen is used. A control unit adjusts the screen's position in real time to the road's incline, dynamically changing the viewing distance and improving the alignment between the virtual image and the real environment.

[0006] DE 11 2017 006 061 T5 describes a 3D augmented reality display system that generates virtual images with multiple depth levels, particularly for vehicle HUDs. The invention uses an extended "image realization surface" that is inclined relative to the optical axis of the projection optics. Due to this inclination, different areas of the surface are located at different distances from the focal point of the optics. A source image projected onto or generated in these different areas results in virtual images that appear to the viewer at different apparent depths, thus conveying a 3D impression.

[0007] US 2020 / 0018977 A1 describes an automotive head-up display system that uses a single image generation unit (PGU) to generate multiple virtual images at varying distances. The PGU's display area is divided into at least two separate zones. An optical imaging module directs the light emitted from these zones to the windshield via optical paths of different lengths. These varying path lengths create different object distances, resulting in the projection of virtual images at different depths for the driver and reducing costs.

[0008] To improve the user experience in XR technology and address one or more of the problems mentioned above, it may be beneficial to implement multi-plane projection with laser beam scanning. SUMMARY

[0009] There is a need to provide an improved concept for an image projection system.

[0010] Such a need can be met by the subject matter of one of the claims.

[0011] One or more embodiments provide an image projection system comprising a first transmitter configured to generate first light rays corresponding to a first projection plane and to transmit the first light rays along a first transmission path; a first collimating lens arranged on the first transmission path, the first collimating lens being configured to receive the first light rays and to generate first collimated light rays to be projected onto an eye to reproduce a first projection image perceived on the first projection plane; a second transmitter configured to generate second light rays corresponding to a second projection plane different from the first projection plane and to transmit the second light rays along a second transmission path;a second collimating lens arranged on the second transmission path, wherein the second collimating lens is configured to receive the second light rays and to generate second collimated light rays to be projected onto the eye to reproduce a second projected image that is perceived on the second projection plane; a first beam combiner arranged at an intersection of the first transmission path and the second transmission path, wherein the first beam combiner is configured to transmit the first collimated light rays and the second collimated light rays on a combined transmission path;and a scanner arranged on the combined transmission path, the scanner being configured to receive the first collimated light beams and the second collimated light beams and to direct the first collimated light beams and the second collimated light beams according to a scanning pattern in order to reproduce the first projection image and the second projection image on the eye.

[0012] One or more embodiments provide an image projection system comprising a transmitter configured to generate first light rays corresponding to a first projection plane, to generate second light rays corresponding to a second projection plane, and to successively transmit the first light rays and the second along a transmission path;a movable collimating lens arranged on the transmission path and configured to move axially relative to the transmitter such that a minimum axial distance from the transmitter changes, wherein the movable collimating lens is configured to receive the first light rays when it is at a first minimum axial distance from the transmitter, to produce first collimated light rays to be projected onto an eye to reproduce a first projection image perceived on the first projection plane, to receive the second light rays when they are at a second minimum axial distance from the transmitter which differs from the first minimum axial distance, and to produce second collimated light rays to be projected onto the eye to reproduce a second projection image perceived on the second projection plane which differs from the first projection plane;and a scanner arranged on the transmission path, the scanner being configured to receive the first collimated light rays and the second collimated light rays and to direct the first collimated light rays and the second collimated light rays according to at least one scanning pattern in order to reproduce the first projection image and the second projection image on the eye.

[0013] One or more embodiments provide an image projection system comprising a transmitter configured to generate first light rays corresponding to a first projection plane, to generate second light rays corresponding to a second projection plane, and to transmit the first light rays and the second light rays sequentially along a transmission path; a collimating lens arranged on the transmission path, wherein the first collimating lens is configured to receive the first light rays, to transmit the first light rays as first collimated light rays, to receive the second light rays, and to transmit the second light rays as second collimated light rays; an adjustable optical element arranged on the transmission path and configured to adjust its focal length to have at least a first focal length corresponding to the first projection plane and a second focal length corresponding to the second projection plane.which corresponds to the second projection plane, comprising, wherein the adjustable optical element is configured to receive the first collimated light rays when its focal length is set to the first focal length, and to transmit the first collimated light rays as first compensated light rays to be projected onto an eye to reproduce a first projection image perceived on the first projection plane, and wherein the adjustable optical element is configured to receive the second collimated light rays when its focal length is set to the second focal length, and to transmit the second collimated light rays as second compensated light rays to be projected onto the eye to reproduce a second projection image perceived on the second projection plane, which differs from the first projection plane; and a scanner arranged on the transmission path,wherein the scanner is configured to receive the first compensated light rays and the second compensated light rays and to direct the first compensated light rays and the second compensated light rays according to at least one scanning pattern in order to reproduce the first projection image and the second projection image on the eye.

[0014] One or more embodiments provide an image projection system comprising a first plurality of monochromatic emitters configured to emit first polarized light rays corresponding to a first projection plane; a first plurality of collimating lenses corresponding to the first plurality of monochromatic emitters, each collimating lens being configured to receive a first polarized light ray from another of the first plurality of monochromatic emitters, such that the first plurality of collimating lenses produce first polarized collimated light rays to be projected onto an eye to reproduce a first projection image perceived on the first projection plane; and a second plurality of monochromatic emitters configured to emit second polarized light rays corresponding to a second projection plane.a second plurality of collimating lenses corresponding to the second plurality of monochromatic transmitters, each of the second plurality of collimating lenses configured to receive a second polarized light beam from another of the second plurality of monochromatic transmitters, such that the second plurality of collimating lenses produces second polarized collimated light beams to be projected onto the eye to reproduce a second projection image perceived on the second projection plane; a polarizing beam combiner arranged at an intersection of the first polarized collimated light beams and the second polarized collimated light beams to focus the first polarized collimated light beams and the second polarized collimated light beams onto a combined transmission path;and a scanner arranged on the combined transmission path, the scanner being configured to receive the first polarized collimated light beams and the second polarized collimated light beams and to direct the first polarized collimated light beams and the second polarized collimated light beams according to a scanning pattern in order to reproduce the first projection image and the second projection image on the eye.

[0015] One or more embodiments provide an image projection system comprising a first plurality of monochromatic emitters configured to emit a first plurality of light rays corresponding to a plurality of projection planes perceived at different distances; a first plurality of collimating lenses corresponding to the first plurality of monochromatic emitters, each of the first plurality of collimating lenses being configured to receive a corresponding light ray from another of the first plurality of monochromatic emitters, such that the first plurality of collimating lenses produce a first plurality of collimated light rays to be projected onto an eye to reproduce a plurality of projection images, each of which is perceived on another of the plurality of projection planes;and a scanner trained to receive the first plurality of collimated light rays and to direct the first plurality of collimated light rays according to a scanning pattern in order to reproduce the plurality of projection images onto the eye. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Examples of implementation are described herein with reference to the accompanying drawings. Fig. 1A is a diagram of an image projection system 100 according to one or more embodiments; Fig. 1B illustrates an image projection onto an eye according to one or more embodiments, in which the virtual image is projected at optical infinity; Fig. 1C shows an image projection onto an eye according to one or more embodiments, wherein the virtual image is projected at a short distance D which is less than optical infinity; Fig. Figure 2 is a schematic diagram of a multi-level image projection system according to one or more embodiments; Fig. 3A and Fig. Figure 3B are schematic representations of a projection module of a multi-level image projection system according to one or more embodiments; Fig. 4A and Fig. Figure 4B shows schematic representations of another projection module of a multi-level image projection system according to one or more embodiments; Fig. Figure 5 is a schematic diagram of another projection system of a multi-level image projection system according to one or more embodiments; and Fig. Figure 6 is a schematic diagram of another multi-level image projection system according to one or more embodiments. DETAILED DESCRIPTION

[0017] Several exemplary embodiments are described in detail below with reference to the accompanying drawings. It should be noted that these exemplary embodiments serve only illustrative purposes and are not intended to be restrictive. For example, while exemplary embodiments may be described as having a plurality of features or elements, this should not be interpreted as meaning that all of these features or elements are necessary for implementing the exemplary embodiments. Instead, in other exemplary embodiments, some of the features or elements may be omitted or replaced by alternative features or elements. Furthermore, additional features or elements may be provided beyond those expressly shown and described, such as conventional sensor component parts.

[0018] Features of different embodiments can be combined to form further embodiments, unless specifically stated otherwise. Modifications or alterations described in relation to one embodiment may also be applicable to other embodiments. In some cases, known structures and devices are shown in block diagram form rather than in detail to avoid obscuring the embodiments.

[0019] Furthermore, equivalent or identical elements, or elements with equivalent or identical functionality, are designated by equivalent or identical reference symbols in the following description. Since the same reference symbols are given to identical or functionally equivalent elements in the figures, repeated descriptions for elements provided with the same reference symbols can be omitted. Thus, descriptions provided for elements with the same or similar reference symbols are mutually interchangeable.

[0020] Connections or couplings between elements shown in the drawings or described herein may be wired or wireless unless otherwise noted. Furthermore, such connections or couplings may be direct connections or couplings without any additional intervening elements, or indirect connections or couplings with one or more additional intervening elements, provided that the general purpose of the connection or coupling, for example, transmitting a certain type of signal or transmitting a certain type of information, is substantially maintained.

[0021] The term “essentially” can be used here to account for small manufacturing tolerances (e.g., within 5%) that are considered acceptable in the industry without deviating from the aspects of the embodiments described here.

[0022] In the present disclosure, expressions including ordinal numbers, such as "first," "second," and / or the like, may modify various elements. However, such elements are not limited by the preceding expressions. The above expressions do not, for example, restrict the order and / or importance of the elements. The above expressions are used solely for the purpose of distinguishing one element from the others. For example, a first box and a second box denote different boxes, although both are boxes. For instance, a first element could be designated as a second element, and similarly, a second element could be designated as a first element, without departing from the scope of protection afforded by the present disclosure.

[0023] Examples relate to optical sensors and optical sensor systems, and to obtaining information via optical sensors and optical sensor systems. A sensor can refer to a component that converts a physical quantity to be measured into an electrical signal, for example, a current signal or a voltage signal. The physical quantity can be, for example, electromagnetic radiation such as visible light, infrared (IR) radiation, or another type of illumination signal, or it can exhibit a current or voltage, but this is not limited to such possibilities. For example, an image sensor can be a silicon chip inside a camera that converts photons of light coming from a lens into voltages. The larger the active area of ​​the sensor, the more light can be collected to create an image.

[0024] In our usage, a sensor component can refer to a device that includes a sensor and other components, such as a bias circuit, an analog-to-digital converter, or a filter. A sensor component can be integrated on a single chip, although in other embodiments, multiple chips or even off-chip components may be used to implement a sensor component.

[0025] In the field of augmented reality (XR) technologies, an eye-tracking sensor can be used to detect and track the direction in which a user is looking. This allows the XR system to employ foveated rendering, a technique that shifts a highly detailed region of an image to align with a projection onto the fovea. Dynamic foveated rendering follows the user's focus direction (i.e., their gaze) in real time using eye-tracking or gaze-tracking, producing a sharp image where the user's retina is looking, rather than at some fixed location. The embodiments disclosed here are directed toward the detection and tracking of an eye direction (i.e., a focus direction), and in particular, the detection and tracking of a user's eye's foveal position to compensate for a scanning operation of a scanning system.Based on the detected focus direction and / or the detected fovea position, a system control is designed to set one or more system parameters, including: a sampling frequency of a scanning structure, a sampling pattern, a light pulse emission time of a red-green-blue (RGB) projection and / or a beamwidth of an RGB projection.

[0026] Fig. Figure 1A is a diagram of an image projection system 100 according to one or more embodiments. The image projection system 100 comprises at least one projection module that projects images into one or more (virtual) projection planes according to a scanning pattern. In particular, visible light (VL) projections, such as red-green-blue (RGB) projections, are projected onto an eye according to a pre-programmed scanning pattern (e.g., a grid or a Lissajous pattern), with RGB light pulses tracking the pattern.

[0027] A projection module can be provided for each eye, projecting stereoscopic images that include a left-eye image and a right-eye image. In this example, two projection modules, 110a and 110b, are provided. The image projection system 100 itself can be glasses, but also any other XR projection system (e.g., HUD, HMD, etc.). The glasses include a combining lens 130a, 130b (e.g., spectacle lenses) for each projection module 110a, 110b, which receives the light rays emitted by a corresponding projection module 110a, 110b and projects (e.g., deflects) the light rays onto the corresponding eye according to a virtual projection plane that corresponds to the virtual distance at which the images are perceived.

[0028] Fig. Figure 1B illustrates an image projection onto an eye according to one or more embodiments, in which the virtual image is projected at optical infinity. Fig. Figure 1C shows an image projection onto an eye according to one or more embodiments, in which the virtual image is projected at a short distance D that is less than optical infinity. In this context, the term "optical infinity" or "infinity focus" refers to the state in which a lens or other optical system forms an image of an object at an infinite distance. This corresponds to the focal point for parallel light rays. In other words, light rays emanating from a selected point of a virtual image are sent parallel to each other such that the virtual image is perceived by an eye at an infinite distance. When an optical system (e.g., a human eye) looks at optical infinity, it forms the image precisely in the focal plane of the optical system.A relaxed (normal vision 20 / 20) human eye projects an image of optical infinity onto the retina, which makes a distant object appear sharp. One could say that the (virtual) projection plane, on which the virtual image is perceived as being reproduced, is located at an infinite distance, as in... Fig. Figure 1B shows that both the actual (real) light rays and the virtual light rays extending from the combiner lens 130 are emitted as parallel light rays. Virtual light rays are virtual extensions of the actual light rays, representing a virtual image in virtual space on the virtual projection plane. A projected distance of 9.5 meters corresponds to optical infinity from the effort perspective, and an image projected at 9.5 meters covers an eye accommodation range from 5 meters to infinity.

[0029] In contrast, diverging light rays cause an image to be perceived at a shorter distance. As in Fig. As can be seen in Figure 1C, the actual light rays emitted from the combining lens 130 towards the eye are diverging rays, while the virtual light rays extend outwards from the combining lens 130, away from the eye, as converging rays. The virtual light rays converge in a projection plane where the image is to be perceived. This projection plane is perceived at a distance D from the combining lens 130, resulting in the image being perceived at that distance. When an image is projected at optical infinity, the eye is considered relaxed. When an image is projected at a shorter distance, the eye is said to be accommodating.

[0030] Fig. Figure 2 is a schematic diagram of a multi-plane image projection system 200 according to one or more embodiments. The multi-plane image projection system 200 comprises a projection module 210, which includes N RGB light modules, a beam combiner 214, and a microelectromechanical system (MEMS) mirror 225, which functions as a scanner, where N is an integer greater than 1. The N RGB light modules include a first RGB light module 211i configured to emit RGB light beams that are projected to optical infinity. The N RGB light modules further include at least one additional RGB light module configured to emit RGB light beams that are projected at a preconfigured distance less than optical infinity. The at least one additional RGB light module includes a second RGB light module 211i, but further RGB light modules may also be present.

[0031] Each of the additional RGB light modules is configured to emit RGB light beams corresponding to a different projection plane. Each other projection plane is projected at a different distance relative to the other projection planes. Thus, the Projection Module 210 comprises N dedicated RGB light modules configured to project onto N projection planes at N different distances, with one of these N projection planes located at optical infinity. The Projection Module 210 is capable of projecting images from a single projection plane or simultaneously projecting images from two or more projection planes, including simultaneous projection onto all N projection planes, by emitting from corresponding RGB light modules.

[0032] Each of the N RGB light modules 211i, 211d, etc., comprises an RGB light unit (i.e., a transmitter) 212i, 212d, etc., with a plurality of light sources, comprising red (R), green (G), and blue (B) monochromatic light sources (e.g., laser diodes or LEDs). The two RGB light units 212i, 212d in this example are configured to generate red, green, and blue light beams in the visible light spectrum, corresponding to the image data to be projected onto the retina of a user's eye. Each RGB light unit 212i, 212d is configured to transmit the red, green, and blue light beams along a respective transmission path, which are to be combined into a combined transmission path by the beam combiner 214. Each RGB light pulse can represent one image pixel of an RGB image.Each RGB light pulse can comprise any combination of a red light pulse, a green light pulse, and / or a blue light pulse emitted simultaneously, encompassing one, two, or three colors in combination at controlled intensities according to the desired hue of the respective image pixel. Accordingly, an RGB light pulse can also be referred to as a pixel light pulse.

[0033] The beam combiner 214 is located at the intersection of at least two RGB light module transmission paths to direct the received light along the combined transmission path toward the MEMS mirror 225. The beam combiner 214 can, for example, be an optical beam splitter configured to have high transmittance with respect to the RGB light beams emanating from the RGB light unit 212d and high reflectivity with respect to the RGB light beams emanating from the RGB light unit 212i. Thus, the RGB light beams emanating from the RGB light unit 212d can pass through the beam combiner 214 to be coupled into the combined transmission path, and the RGB light beams emanating from the RGB light unit 212i can be reflected by the beam combiner 214 to be coupled into the combined transmission path.Thus, the RGB light beams are coupled into the combined transmission path via the optical beam splitter 214.

[0034] Each of the N RGB light modules 211i, 211d, etc., further comprises a beam collimator (e.g., a collimation lens) 213i, 213d, etc., which is arranged upstream of the beam combiner 214 on a respective transmit path. The beam collimators 213i, 213d, etc., are arranged such that different divergence angles are implemented with respect to the RGB light beams originating from different RGB light units. The different divergence angles are used to implement different projection planes of the N projection planes.

[0035] The beam collimator 213d is configured to have a minimum interspace distance g1 (i.e., a minimum axial distance) from the RGB light unit 212d. As a result of this minimum interspace distance g1, the beam collimator 213d is configured to receive the RGB light beams from the RGB light unit 212d and generate collimated light beams to be projected onto an eye to reproduce a first projection image perceived on the first projection plane. The divergence angle generated by the beam collimator 213d is greater than zero, resulting in the first projection plane being projected at a predefined distance less than optical infinity. Furthermore, it is possible to mount the beam collimator 213d on a movable platform to adjust the minimum interspace distance g1, thereby adapting the perceived distance of the corresponding projection plane.

[0036] In contrast, the beam collimator 213i is arranged to have a minimum interspace distance g2 (i.e., a minimum axial distance) from the RGB light unit 212i, which differs from the minimum interspace distance g1. As a result of the minimum interspace distance g2, the beam collimator 213i is configured to receive the RGB light beams from the RGB light unit 212i and generate collimated light beams to be projected onto an eye to reproduce a second projected image perceived on the first projection plane, which is located at optical infinity. The divergence angle produced by the beam collimator 213i is zero, resulting in parallel RGB light beams, with the second projection plane projected at optical infinity.It is also possible to arrange the beam collimator 213i on a movable platform in order to adjust the minimum interspace distance g2, thereby adjusting the perceived distance of the corresponding projection plane.

[0037] A MEMS mirror is a mechanically moving mirror (i.e., a MEMS micromirror) integrated onto a semiconductor chip (not shown). The MEMS mirror 225 can be suspended by mechanical springs (e.g., torsion bars) or bending elements and is configured to rotate around two axes, e.g., about an x-axis for horizontal scanning and about a y-axis (i.e., orthogonal to the x-axis) for vertical scanning. By using two scanning axes, the MEMS mirror 225 is capable of two-dimensional (2D) scanning and can be used for raster or Lissajous scanning operations.

[0038] The MEMS mirror 225 can be a resonator (i.e., a resonant MEMS mirror) configured to oscillate "side to side" around each scanning axis, such that the light reflected by the MEMS mirror oscillates back and forth in a corresponding scanning direction (e.g., a horizontal scanning direction or a vertical scanning direction). A scanning period, or oscillation period, is defined, for example, by a complete oscillation from a first edge of a field of view (e.g., first side) to a second edge of the field of view (e.g., second side) and then back to the first edge. One mirror period of a MEMS mirror corresponds to one scanning period.

[0039] Thus, the field of view is scanned in both scanning directions by changing the angles θx and θy of the MEMS mirror 225 on its respective scanning axes. A specific scanning pattern can be implemented by independently shaping an amplitude range (i.e., an angular range of motion) and a drive frequency with respect to rotation about each axis. Furthermore, the shape of a drive waveform for the drive signal used to drive the MEMS mirror 225 about each scanning axis can be shaped independently to further define the scanning pattern. For example, the drive waveforms for both scanning axes can be sinusoidal, or one can be sinusoidal and the other sawtooth-shaped, etc.

[0040] Accordingly, the MEMS mirror 225 is positioned on the combined transmit path and is used to direct the RGB light it receives according to the scanning pattern in order to project images perceived on different projection planes onto the retina of the eye. The MEMS mirror 225 further directs the RGB light along the combined transmit path towards the beam combiner 130, which then directs the RGB light towards the eye to project images onto it. The beam combiner 130 is responsible for projecting the RGB images into the user's eye by directing the RGB images into the user's field of vision. In other words, the beam combiner 130 delivers RGB images to the user's eye, generated by the RGB light units 212d, 212i, etc., according to a controlled scanning pattern and the preconfigured projection planes.

[0041] Each RGB light pulse can represent one pixel of an RGB image. Each RGB light pulse can comprise any combination of a red light pulse, a green light pulse, and / or a blue light pulse emitted simultaneously, encompassing one, two, or three colors in combination at controlled intensities according to the desired hue of the respective image pixel. Accordingly, an RGB light pulse can also be referred to as a pixel light pulse.

[0042] In summary, the multi-plane image projection system 200 comprises a first transmitter configured to generate first light rays corresponding to a first projection plane and to transmit the first light rays along a first transmission path; a first collimating lens arranged on the first transmission path, the first collimating lens being configured to receive the first light rays and to generate first collimated light rays to be projected onto an eye to reproduce a first projection image perceived on the first projection plane; a second transmitter configured to generate second light rays corresponding to a second projection plane different from the first projection plane and to transmit the second light rays along a second transmission path;a second collimating lens arranged on the second transmission path, wherein the second collimating lens is configured to receive the second light rays and to generate second collimated light rays to be projected onto the eye to reproduce a second projected image that is perceived on the second projection plane; a first beam combiner arranged at an intersection of the first transmission path and the second transmission path, wherein the first beam combiner is configured to transmit the first collimated light rays and the second collimated light rays on a combined transmission path;and a scanner arranged on the combined transmission path, the scanner being configured to receive the first collimated light beams and the second collimated light beams and to direct the first collimated light beams and the second collimated light beams according to a scanning pattern in order to reproduce the first projection image and the second projection image on the eye.

[0043] The multi-level image projection system 200 further comprises a second beam combiner positioned between the scanner and the eye, wherein the second beam combiner receives the first collimated light beams and the second collimated light beams and directs the first collimated light beams and the second collimated light beams towards the eye.

[0044] The first collimating lens is positioned at a first minimum distance from the first transmitter, and the second collimating lens is positioned at a second minimum distance from the second transmitter, which differs from the first minimum distance. The first collimating lens is either fixed, such that the first minimum distance is fixed, or movable, such that the first minimum distance is adjustable, and the second collimating lens is either fixed, such that the second minimum distance is fixed, or movable, such that the second minimum distance is adjustable.

[0045] The first transmitter can be a primary RGB transmitter, comprising a red light source, a green light source, and a blue light source, and the first projected image is a primary RGB image. The second transmitter can be a secondary RGB transmitter, and the second projected image is a secondary RGB image. Alternatively, the first transmitter can be a primary monochromatic transmitter, and the second transmitter can be a secondary monochromatic transmitter, emitting the same color as the primary monochromatic transmitter. The first and second transmitters are configured to emit the primary and secondary light beams, respectively, to simultaneously project the first and second images onto the eye.

[0046] Fig. 3A and Fig. Figure 3B shows schematic representations of a projection module 310 of a multiplane image projection system according to one or more embodiments. As similarly described with respect to the multiplane image projection system 200, a projection module is part of a multiplane image projection system, which may further include a beam combiner 130. Here, the projection module 310 comprises a single RGB light unit (i.e., a transmitter) 212, and a movable beam collimator 213 is arranged to have a minimum variable interspace distance vg (i.e., a minimum axial distance) from the RGB light unit 212. For example, the movable beam collimator 213 may be attached to a movable platform 315, which moves to change (i.e., increase or decrease) the minimum variable interspace distance vg in order to project images onto different projection planes.In other words, the minimum variable interspace distance vg can be varied to project images at specific preselected distances, encompassing optical infinity or less than optical infinity. Light beams from the movable beam collimator 213 are received by the MEMS mirror 225, which directs the light beams to the beam combiner 130 (not shown) according to a scanning pattern.

[0047] Therefore, only a single, focusable RGB laser module is required for the projection of N projection planes. However, only one projection plane can be projected at a time (i.e., no transparent virtual objects). Furthermore, each laser module is equipped with a focusing mechanism (i.e., the movable beam collimator 213).

[0048] As in Fig. As shown in Figure 3A, a first image frame (Frame 1) is projected onto a projection plane, which is perceived at a first pre-selected distance. Fig. In 3B, a second image frame (frame 2) is projected onto a projection plane, which is perceived at a second pre-selected distance. Thus, the projection module 310 provides a successive plane projection using laser focusing, and the minimum variable interspace distance vg can be set on a frame-by-frame basis.

[0049] In summary, the image projection system comprises a transmitter configured to generate first light rays corresponding to a first projection plane, to generate second light rays corresponding to a second projection plane, and to successively transmit the first light rays and the second along a transmission path;a movable collimating lens arranged on the transmission path and configured to move axially relative to the transmitter such that a minimum axial distance from the transmitter changes, wherein the movable collimating lens is configured to receive the first light rays when it is at a first minimum axial distance from the transmitter, to produce first collimated light rays to be projected onto an eye to reproduce a first projection image perceived on the first projection plane, to receive the second light rays when they are at a second minimum axial distance from the transmitter which differs from the first minimum axial distance, and to produce second collimated light rays to be projected onto the eye to reproduce a second projection image perceived on the second projection plane which differs from the first projection plane;and a scanner arranged on the transmission path, the scanner being configured to receive the first collimated light rays and the second collimated light rays and to direct the first collimated light rays and the second collimated light rays according to at least one scanning pattern in order to reproduce the first projection image and the second projection image on the eye.

[0050] The image projection system further comprises a beam combiner located between the scanner and the eye, wherein the beam combiner receives the first collimated light beams and the second collimated light beams and directs the first collimated light beams and the second collimated light beams towards the eye.

[0051] Fig. 4A and Fig. Figure 4B shows schematic representations of a projection module 410 of a multiplane image projection system according to one or more embodiments. As similarly described with respect to the multiplane image projection system 200, a projection module is part of a multiplane image projection system, which may further include a beam combiner 130. Here, the projection module 410 comprises a single RGB light unit (i.e., a transmitter) 212, a fixed beam collimator 213, and an adjustable optical element 416 (e.g., an adjustable lens) having an adjustable shape. In particular, the shape of the adjustable optical element 416 can be adjusted to change its focal length. Thus, different divergence angles with respect to the RGB light beams emanating from the RGB light unit 212 can be implemented.The different divergence angles are used to implement different projection planes, including a projection plane projected to optical infinity and projection planes projected at preselected distances shorter than optical infinity.

[0052] The interspace distance g (i.e., an axial distance) from the RGB light unit 212 to the fixed beam collimator 213 remains constant. That is, a single interspace distance g is used for all projection planes. Light beams from the movable beam collimator 416 are received by the MEMS mirror 225, which directs the light beams to the beam combiner 130 (not shown) according to a scanning pattern.

[0053] As in Fig. As shown in Figure 4A, a first image frame (frame 1) is projected onto a projection plane, which is perceived at a first preselected distance. The shape of the adjustable optical element 416 is such that the divergence angle of the RGB light rays is greater than zero. Therefore, the first preselected distance is less than optical infinity. Fig. 4A the adjustable optical element 416 takes the form of a negative lens with a preselected focal length which can be adjusted depending on the desired distance at which the projection plane is to be projected.

[0054] In Fig. 4B A second image frame (frame 2) is projected onto a projection plane, which is perceived at a second preselected distance. The shape of the adjustable optical element 416 is such that the divergence angle of the RGB light rays is zero, thus ensuring that the RGB light rays remain parallel to each other. Therefore, the second preselected distance corresponds to optical infinity. In Fig. 4B, the adjustable optical element 416 takes the form of a zero-power optical element.

[0055] Thus, the projection module 410 provides a successive plane projection via the adjustable optical element 416, and the shape of the adjustable optical element 416 can be set on a time basis.

[0056] In summary, the image projection system comprises a transmitter configured to generate first light rays corresponding to a first projection plane, to generate second light rays corresponding to a second projection plane, and to successively transmit the first and second light rays along a transmission path; a collimating lens arranged on the transmission path, the first collimating lens being configured to receive the first light rays, to transmit the first light rays as first collimated light rays, to receive the second light rays, and to transmit the second light rays as second collimated light rays; and an adjustable optical element arranged on the transmission path and configured to adjust its focal length to include at least a first focal length corresponding to the first projection plane and a second focal length corresponding to the second projection plane.

[0057] The adjustable optical element is configured to receive the first collimated light rays when its focal length is set to the first focal length and to emit these first collimated light rays as the first compensated light rays to be projected onto the eye to reproduce a first projection image perceived on the first projection plane. The adjustable optical element is configured to receive the second collimated light rays when its focal length is set to the second focal length and to emit these second collimated light rays as the second compensated light rays to be projected onto the eye to reproduce a second projection image perceived on the second projection plane, which differs from the first projection plane.

[0058] The image projection system further comprises a scanner arranged on the transmission path, the scanner being configured to receive the first compensated light rays and the second compensated light rays, and to direct the first compensated light rays and the second compensated light rays according to at least one scanning pattern in order to reproduce the first projection image and the second projection image to the eye.

[0059] The image projection system further comprises a beam combiner located between the scanner and the eye, wherein the beam combiner receives the first collimated light beams and the second collimated light beams and directs the first collimated light beams and the second collimated light beams towards the eye.

[0060] The transmitter can be an RGB transmitter, comprising a red light source, a green light source, and a blue light source, and the first and second projection images are RGB images.

[0061] Fig. Figure 5 is a schematic diagram of a projection system 510 of a multiplane image projection system according to one or more embodiments. As similarly described with respect to the multiplane image projection system 200, a projection module is part of a multiplane image projection system, which may further include a beam combiner 130. Although not shown, the projection module 510 also includes a MEMS mirror 225 that receives light beams and directs them according to a scanning pattern to reproduce images to an eye.

[0062] The projection module 510 comprises a first plurality of monochromatic transmitters 212rp, 212gp, and 212bp configured to emit first polarized light beams according to a first projection plane. Specifically, the first plurality of monochromatic transmitters 212rp, 212gp, and 212bp generates p-polarized light beams, with transmitter 212rp generating red p-polarized light beams, transmitter 212gp generating green p-polarized light beams, and transmitter 212bp generating blue p-polarized light beams. Together, the transmission of the red, green, and blue polarized light beams is synchronized to form an image pixel of an RGB image, and the transmitters 212rp, 212gp, and 212bp are used to reproduce a first RGB image.

[0063] The projection module 510 further comprises a first plurality of collimation lenses 213rp, 213gp and 213bp corresponding to the first plurality of monochromatic emitters 212rp, 212gp and 212bp, each of the first plurality of collimation lenses 213rp, 213gp and 213bp being configured to receive a first polarized light beam from another of the first plurality of monochromatic emitters 212rp, 212gp and 212bp, such that the first plurality of collimation lenses 213rp, 213gp and 213bp produce first polarized collimated light beams to be projected onto an eye to reproduce a first projection image that is perceived on the first projection plane.

[0064] Each of the first plurality of collimating lenses 213rp, 213gp, and 213bp is arranged at an interspace distance g2 from its respective transmitter 212rp, 212gp, and 212bp. As a result of the interspace distance g2, each of the first plurality of collimating lenses 213rp, 213gp, and 213bp is configured to receive monochromatic, p-polarized light rays and to produce collimated light rays to be projected onto an eye to reproduce a projected image perceived at optical infinity.

[0065] The projection module 510 further comprises a polarizing beam combiner 523 configured to reflect p-polarized light and transmit s-polarized light in order to couple different types of polarized light into a combined transmit path on which the MEMS mirror 225 (not shown) is arranged. The polarizing beam combiner 523 directs light beams of different polarizations toward the MEMS mirror 225.

[0066] The projection module 510 further comprises a first plurality of dichroic mirrors 517 and 518 configured to direct the first polarized collimated light beams toward the polarizing beam combiner 523. In this example, the dichroic mirrors 517 and 518 are configured to emit red light received from transmitter 212rp and to reflect green and blue light received from transmitters 212gp and 212bp, respectively. Thus, the first polarized collimated light beams are coupled into a common transmission path by the dichroic mirrors 517 and 518 and directed toward the polarizing beam combiner 523.

[0067] The projection module 510 further comprises a second plurality of monochromatic emitters 212rs, 212gs, and 212bs configured to emit second polarized light beams corresponding to a second projection plane. Specifically, the second plurality of monochromatic emitters 212rs, 212gs, and 212bs generates s-polarized light beams, wherein emitter 212rs generates red s-polarized light beams, emitter 212gs generates green s-polarized light beams, and emitter 212bs generates blue s-polarized light beams. Together, the red, green, and blue polarized light beams form an image pixel of an RGB image, and emitters 212rs, 212gs, and 212bs are used to reproduce a second RGB image.

[0068] The projection module 510 further comprises a first plurality of collimation lenses 213rs, 213gs and 213bs corresponding to the second plurality of monochromatic emitters 212rs, 212gs and 212bs, each of the second plurality of collimation lenses 213rs, 213gs and 213bs being configured to receive a second polarized light beam from another of the second plurality of monochromatic emitters 212rs, 212gs and 212bs, such that the second plurality of collimation lenses 213rs, 213gs and 213bs produce second polarized collimated light beams to be projected onto an eye to reproduce a second projection image perceived in the second projection plane.

[0069] Each of the second plurality of collimating lenses 213rs, 213gs, and 213bs is arranged at a minimum interspace distance g1 (i.e., a minimum axial distance) from its respective transmitter 212rs, 212gs, and 212bs. As a result of the minimum interspace distance g1, each of the second plurality of collimating lenses 213rs, 213gs, and 213bs is configured to receive monochromatic, s-polarized light rays and to produce collimated light rays to be projected onto an eye to produce a projected image perceived at a distance less than optical infinity.

[0070] The projection module 510 further comprises a second plurality of dichroic mirrors 521 and 522 configured to direct the second polarized collimated light beams toward the polarizing beam combiner 523. In this example, the dichroic mirrors 521 and 522 are configured to transmit red light received from transmitter 212rs and to reflect green and blue light received from transmitters 212gs and 212bs, respectively. Thus, the second polarized collimated light beams are coupled into a common transmission path by the dichroic mirrors 521 and 522 and directed toward the polarizing beam combiner 523.

[0071] The polarizing beam combiner 523 is positioned at the intersection of the first polarized collimated light beams and the second polarized collimated light beams to direct them onto a combined transmission path. Thus, both the p-polarized and s-polarized light beams are directed to the MEMS mirror 225, which is positioned on the combined transmission path. The MEMS mirror 225 is configured to receive the first polarized collimated light beams and the second polarized collimated light beams and direct them according to a scanning pattern to reproduce the first and second projection images on the eye.

[0072] The polarizing beam combiner 523 comprises a first surface at which the p-polarized light rays are received and a second surface at which the s-polarized light rays are received. The polarizing beam combiner 523 is configured to reflect the p-polarized light rays received at the first surface and transmit the s-polarized light rays received at the second surface, or to reflect the s-polarized light rays received at the second surface and transmit the p-polarized light rays received at the first surface. In other words, the p-polarized and s-polarized systems can exchange positions, and the polarizations of the reflecting and transmitting surfaces of the polarizing beam combiner 523 can be designed accordingly.

[0073] The projection module 510 further comprises a beam combiner 130 (not shown) which is arranged between the scanner 225 and the eye, wherein the beam combiner 130 receives the first polarized collimated light beams and the second polarized collimated light beams and directs the first polarized collimated light beams and the second polarized collimated light beams towards the eye.

[0074] Fig. Figure 6 is a schematic diagram of a multi-plane image projection system 600 according to one or more embodiments. The multi-plane image projection system 600 comprises a dichroic mirror system used to couple the light beams received from several monochromatic transmitters into a combined transmission path on which the MEMS mirror 225 is arranged for receiving the light beams.

[0075] The multi-plane image projection system 600 comprises a first plurality of monochromatic emitters 212r1, 212r2, 212r3 configured to emit a first plurality of light rays corresponding to a plurality of projection planes perceived at different distances. In other words, each of the first plurality of monochromatic emitters 212r1, 212r2, 212r3 emits light on a different projection plane, and the number of monochromatic emitters is equal to the number of projection planes onto which the system 600 can project. Different interspace distances g1, g2, and g3 are used to define the perceived distance of each projection plane.

[0076] As can easily be seen, each of the first plurality of monochromatic transmitters 212r1, 212r2, 212r3 is tuned and synchronized with a corresponding one from a second plurality of monochromatic transmitters 212g1, 212g2, 212g3 and a corresponding one from a third plurality of monochromatic transmitters 212b1, 212b2, 212b.

[0077] Each of the first plurality of monochromatic emitters 212r1, 212r2, 212r3 is configured to emit red light with slightly different wavelengths so that it can propagate correctly in the dichroic mirror system with minimal to no loss (i.e., a lossless process). Similarly, each of the second plurality of monochromatic emitters 212b1, 212b2, 212b3 is configured to emit blue light with slightly different wavelengths so that it can propagate correctly in the dichroic mirror system with minimal to no loss (i.e., a lossless process). Similarly, each of the second plurality of monochromatic emitters 212g1, 212g2, 212g3 is configured to emit green light with slightly different wavelengths so that it can propagate correctly in the dichroic mirror system with minimal to no loss (i.e., a lossless process).Thus, the first majority of monochromatic transmitters are red light transmitters that transmit to each other at different wavelengths, the second majority of monochromatic transmitters are blue light transmitters that transmit to each other at different wavelengths, and the third majority of monochromatic transmitters are green light transmitters that transmit to each other at different wavelengths.

[0078] The multiplane image projection system 600 further comprises a first plurality of collimating lenses 213r1, 213r2, 213r3 corresponding to the first plurality of monochromatic emitters 212r1, 212r2, 212r3, each of the first plurality of collimating lenses 213r1, 213r2, 213r3 being configured to receive a corresponding light beam from another of the first plurality of monochromatic emitters 212r1, 212r2, 212r3, such that the first plurality of collimating lenses produces a first plurality of collimated light beams to be projected onto an eye in order to reproduce a plurality of projection images, each of which is to be perceived on a different one of a plurality of projection planes.

[0079] The multi-plane image projection system 600 further comprises the MEMS mirror 225, which is configured to receive the first plurality of collimated light rays and to direct the first plurality of collimated light rays according to a scanning pattern in order to reproduce the plurality of projection images to the eye.

[0080] The multi-level image projection system 600 further comprises a second plurality of monochromatic transmitters 212b1, 212b2, 212b3, which are configured to emit a second plurality of light rays corresponding to the plurality of projection levels. A second plurality of collimating lenses 213b1, 213b2, 213b3, corresponding to the second plurality of monochromatic emitters 212b1, 212b2, 212b3, is provided, each of the second plurality of collimating lenses 213b1, 213b2, 213b3 being configured to receive a corresponding light beam from another of the first plurality of monochromatic emitters 212b1, 212b2, 212b3, such that the second plurality of collimating lenses 213b1, 213b2, 213b3 produces a second plurality of collimated light beams to be projected onto the eye to reproduce the plurality of projection images, each of which is perceived on another of the plurality of projection planes.

[0081] The multi-plane image projection system 600 further comprises a beam combiner 631, which is arranged at an intersection of the first plurality of collimated light beams (red light) and the second plurality of collimated light beams (blue light) to direct the first plurality of collimated light beams and the second plurality of collimated light beams onto a combined transmission path. The beam combiner 631 can be a dichroic mirror configured to transmit wavelengths corresponding to the first plurality of collimated light beams (e.g., red light) and to reflect wavelengths corresponding to the second plurality of collimated light beams (e.g., blue light).

[0082] The MEMS mirror 225 is arranged on the combined transmit path to receive the first plurality of collimated light beams and the second plurality of collimated light beams and to direct the first plurality of collimated light beams and the second plurality of collimated light beams according to the scanning pattern to reproduce the first projection image and the second projection image to the eye.

[0083] The multi-level image projection system 600 further comprises a second plurality of monochromatic transmitters 212g1, 212g2, 212g3, which are configured to emit a third plurality of light beams corresponding to the plurality of projection levels. A third plurality of collimating lenses 213g1, 213g2, 213g3 corresponding to the third plurality of monochromatic emitters 212g1, 212g2, 212g3, each of the third plurality of collimating lenses 213g1, 213g2, 213g3 being configured to receive a corresponding light beam from another of the third plurality of monochromatic emitters 212g1, 212g2, 212g3, such that the third plurality of collimating lenses 213g1, 213g2, 213g3 produces a third plurality of collimated light beams to be projected onto the eye to reproduce the plurality of projection images, each of which is perceived on another of the plurality of projection planes.

[0084] Another beam combiner 632 is arranged on the combined transmission path between the beam combiner 631 and the MEMS mirror 225 such that it is located downstream of the beam combiner 631 in order to receive the first plurality of collimated light beams and the second plurality of collimated light beams from it. Thus, the beam combiner 632 is arranged at an intersection of the first plurality of collimated light beams, the second plurality of collimated light beams, and the third plurality of collimated light beams in order to direct the first plurality of collimated light beams, the second plurality of collimated light beams, and the third plurality of collimated light beams along the combined transmission path toward the MEMS mirror 225.The beam combiner 632 can be a dichroic mirror configured to transmit wavelengths corresponding to the first and second plural of collimated light beams (e.g., red and blue light) and to reflect wavelengths corresponding to the third plural of collimated light beams (e.g., green light). The beam combiner 632 is responsible for ensuring that all light beams are coupled into the combined transmit path and directed onto the MEMS mirror 225.

[0085] The MEMS mirror 225 is arranged downstream of the beam combiner 632 on the combined transmit path to receive the first plurality of collimated light beams, the second plurality of collimated light beams and the third plurality of collimated light beams and to direct the first plurality of collimated light beams, the second plurality of collimated light beams and the third plurality of collimated light beams according to the scanning pattern to reproduce the plurality of projection images on the eye.

[0086] The multi-level image projection system 600 further comprises a first plurality of dichroic mirrors 633 and 634 configured to direct the first plurality of collimated light rays onto the beam combiner 631, a second plurality of dichroic mirrors 635 and 636 configured to direct the second plurality of collimated light rays onto the beam combiner 631, and a third plurality of dichroic mirrors 637 and 638 configured to direct the third plurality of collimated light rays onto the beam combiner 632.

[0087] Since the first majority of the collimated light rays have slightly different wavelengths, the dichroic mirror 633 transmits the light received from transmitter 612r2 and reflects the light received from transmitter 612r3. Similarly, the dichroic mirror 634 transmits the light received from transmitters 612r2 and 612r3 and reflects the light received from transmitter 612r1.

[0088] Since the second majority of the collimated light rays have slightly different wavelengths, the dichroic mirror 635 transmits the light received from transmitter b2 and reflects the light received from transmitter 612b3. Similarly, the dichroic mirror 636 transmits the light received from transmitters 612b2 and 612b3 and reflects the light received from transmitter 612b1.

[0089] Similarly, since the third majority of the collimated light rays have slightly different wavelengths, dichroic mirror 637 transmits the light received from transmitter 612g2 and reflects the light received from transmitter 612g3. Similarly, dichroic mirror 638 transmits the light received from transmitters 612g2 and 612g3 and reflects the light received from transmitter 612g1.

[0090] Alternatively, 633, 634, 635, 636, 637, 638 can be mirrors with a fixed transmission ratio (e.g. 50:50 transmission:reflection for 633, 635, 637 and 0.6(6):0.3(3) transmission:reflection for 634, 636, 638) to have an equal contribution of all combined wavelengths.

[0091] The first plurality of dichroic mirrors 633, 634 is configured to direct the first plurality of collimated light beams onto a common transmission path, and the first plurality of monochromatic transmitters 212r1, 212r2, 212r3 is configured to transmit essentially the same color of light to each other at different wavelengths.

[0092] The first plurality of dichroic mirrors 635, 636 is configured to direct the second plurality of collimated light beams onto a common transmission path, and the second plurality of monochromatic transmitters 212b1, 212b2, 212b3 is configured to transmit essentially the same color of light to each other at different wavelengths.

[0093] The third plurality of dichroic mirrors 637, 638 is configured to direct the third plurality of collimated light beams onto a common transmission path, and the third plurality of monochromatic transmitters 212g1, 212g2, 212g3 is configured to transmit essentially the same color of light to each other at different wavelengths.

[0094] Each of the first plurality of monochromatic transmitters 212r1, 212r2, 212r3 is paired with one of the first plurality of collimating lenses 213r1, 213r2, 213r3 to form a pair, such that each pair is separated by a distance corresponding to another of the plurality of projection planes, each minimum distance being distinct from the others. Each of the first plurality of collimating lenses 213r1, 213r2, 213r3 is either fixed, such that the respective distance is fixed, or movable, such that the respective distance is adjustable. Similar features can be extended to the second and third plurality of transmitters and collimating lenses.

[0095] In light of the above, the images can be reproduced on multiple projection planes simultaneously or sequentially using the examples described here.

[0096] In addition to the embodiments defined in the claims, further embodiments are provided below. 1. An image projection system, comprising: a transmitter which is configured to generate first light rays corresponding to a first projection plane, to generate second light rays corresponding to a second projection plane, and to transmit the first light rays and the second light rays successively along a first transmission path; A movable collimating lens arranged on the transmission path and configured to move axially relative to the transmitter such that a minimum axial distance from the transmitter changes, wherein the movable collimating lens is configured to receive the first light rays when it is at a first minimum axial distance from the transmitter, to produce first collimated light rays to be projected onto an eye to reproduce a first projection image perceived on the first projection plane, to receive the second light rays when they are at a second minimum axial distance from the transmitter which differs from the first minimum axial distance, and to produce second collimated light rays to be projected onto the eye to reproduce a second projection image perceived on the second projection plane which differs from the first projection plane. a scanner arranged on the transmission path, the scanner being configured to receive the first collimated light beams and the second collimated light beams and to direct the first collimated light beams and the second collimated light beams according to a scanning pattern in order to reproduce the first projection image and the second projection image to the eye. 2. The image projection system according to embodiment 1, further comprising: a beam combiner positioned between the scanner and the eye, wherein the beam combiner receives the first collimated light beams and the second collimated light beams and directs the first collimated light beams and the second collimated light beams towards the eye. 3. The image projection system according to embodiment 1, wherein: the first projection plane is projected into optical infinity, and the second projection plane is projected at a predefined distance that is less than optical infinity. 4. The image projection system according to embodiment 3, wherein the optical infinity corresponds to a virtual distance of at least 9.5 meters. 5. The image projection system according to embodiment 1, wherein: the first projection plane is projected at a first predefined distance, and the second projection plane is projected at a second predefined distance that differs from the first predefined distance. 6. The image projection system according to embodiment 1, wherein: The transmitter can be a first red-green-blue (RGB) transmitter comprising a red light source, a green light source and a blue light source, and the first and second projection images are RGB images. 7. An image projection system, comprising: a transmitter which is configured to generate first light rays corresponding to a first projection plane, to generate second light rays corresponding to a second projection plane, and to transmit the first light rays and the second light rays successively along a first transmission path; a collimating lens arranged on the transmission path, wherein the first collimating lens is configured to receive the first light rays, to transmit the first light rays as first collimated light rays, to receive the second light rays and to transmit the second light rays as second collimated light rays; an adjustable optical element, arranged on the transmission path and configured to adjust its focal length to include at least a first focal length corresponding to the first projection plane and a second focal length corresponding to the second projection plane, wherein the adjustable optical element is configured to receive the first collimated light rays when its focal length is set to the first focal length, and to send the first collimated light rays as first compensated light rays to be projected onto an eye in order to reproduce a first projection image that is perceived on the first projection plane, and wherein the adjustable optical element is configured to receive the second collimated light rays when its focal length is set to the second focal length, and to send the second collimated light rays as second compensated light rays to be projected onto the eye in order to reproduce a second projection image that is perceived on the second projection plane, which is different from the first projection plane; and a scanner arranged on the transmission path, the scanner being configured to receive the first compensated light rays and the second compensated light rays, and to direct the first compensated light rays and the second compensated light rays according to at least one scanning pattern in order to reproduce the first projection image and the second projection image to the eye. 8. The image projection system according to embodiment 7, further comprising: a beam combiner positioned between the scanner and the eye, wherein the beam combiner receives the first collimated light beams and the second collimated light beams and directs the first collimated light beams and the second collimated light beams towards the eye. 9. The image projection system according to embodiment 7, wherein: the first projection plane is projected into optical infinity, and the second projection plane is projected at a predefined distance that is less than optical infinity. 10. is discussed. The image projection system according to embodiment 9, wherein the optical infinity corresponds to a virtual distance of at least 9.5 meters. 11. The image projection system according to embodiment 7, wherein: the first projection plane is projected at a first predefined distance, and the second projection plane is projected at a second predefined distance that differs from the first predefined distance. 12. The image projection system according to embodiment 7, wherein: The transmitter can be a first red-green-blue (RGB) transmitter comprising a red light source, a green light source and a blue light source, and the first and second projection images are RGB images.

[0097] Although the embodiments described herein relate to a MEMS device with a mirror, it should be noted that other implementations may include optical devices other than MEMS mirror devices. Additionally, although some aspects have been described in the context of a device, it is evident that these aspects also represent a description of the corresponding process, where a block or device corresponds to a process step or a feature of a process step. Similarly, aspects described in the context of a process step also represent a description of a corresponding block, element, or feature of a corresponding device.Some or all of the process steps can be performed by (or using) a hardware device, such as a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, some or all of the process steps can be performed by such a device.

[0098] Although various embodiments have been described, it is obvious to those skilled in the art that many further embodiments and implementations are possible within the scope of the disclosure. Accordingly, the invention is not to be limited, except with regard to the appended claims and their correspondences. With regard to the various functions performed by the components or structures (arrangements, devices, circuits, systems, etc.) described above, the terms (including a reference to a “means”) used to describe such components, unless otherwise specified, are to correspond to any component or structure that performs the specified function of the described component (i.e.,which is functionally equivalent), even if it is not structurally equivalent to the disclosed structure that performs the function in the exemplary implementations of the invention shown herein.

[0099] Furthermore, the following claims are hereby included in the detailed description, where each claim may stand alone as a separate example. While each claim may stand alone as a separate embodiment, it should be noted that—although a dependent claim may refer in the claims to a specific combination with one or more other claims—other embodiments may also include a combination of the dependent claim with the subject matter of any other dependent or independent claim. Such combinations are proposed herein unless it is stated that a particular combination is not intended. Furthermore, features of a claim for any other independent claim are also intended to be included, even if that claim is not directly dependent on the independent claim.

[0100] It should further be noted that methods disclosed in the description or in the claims are implemented by a device which includes a means for carrying out each of the respective steps of these methods.

[0101] Furthermore, it is understood that the disclosure of several steps or functions revealed in the description or in the claims should not be interpreted as being in a specific order. Therefore, the disclosure of several steps or functions does not restrict them to a specific order unless these steps or functions are not interchangeable for technical reasons. Furthermore, in some embodiments, a single step may comprise several sub-steps or may be divided into several sub-steps. Such sub-steps may be included and form part of the disclosure of that single step unless they are explicitly excluded.

[0102] Instructions can be executed by one or more processors, such as one or more central processing units (CPUs), digital signal processors (DSPs), general-purpose microprocessors, application-specific integrated circuits (ASICs), field-programmable logic arrays (FPGAs), or any other equivalent integrated or discrete logic circuit arrangement. Accordingly, as used herein, the terms "processor" or "processing circuit arrangement" refer to any of the foregoing structures or any other structure suitable for implementing the techniques described herein. Additionally, in some aspects, the functionality described herein may be provided within dedicated hardware and / or software modules.The techniques could also be fully implemented in one or more circuits or logic elements.

[0103] Thus, the techniques described in this disclosure may be implemented, at least partially, in hardware, software, firmware, or any combination thereof. For example, various aspects of the described techniques may be implemented within one or more processors, comprising one or more microprocessors, DSPs, ASICs, or any other equivalent integrated or discrete logic circuit arrangement, as well as any combination of such components.

[0104] A controller comprising hardware may also execute one or more of the techniques described in this disclosure. Such hardware, software, and firmware may be implemented within the same device or within separate devices to support the various techniques described in this disclosure. Software may be stored on a non-volatile, computer-readable medium such that the non-volatile, computer-readable medium comprises program code or a program algorithm stored thereon which, when executed, causes the controller, via a computer program, to execute the steps of a procedure.Although various embodiments have been disclosed, it is obvious to those skilled in the field that various changes and modifications can be made which will achieve some of the advantages of the concepts disclosed herein without departing from the essence and scope of the invention. It is obvious to those skilled in the art of average skill that other components performing the same functions can be appropriately substituted. It should be noted that other embodiments can be used and structural or logical changes can be made without departing from the scope of the present disclosure. It should be mentioned that features described with reference to a particular figure can be combined with features of other figures, even those not explicitly mentioned.Such modifications of the general concept according to the invention are considered to be covered by the attached claims and their legal equivalents.

[0105] Exemplary embodiment 20 is an image projection system comprising: a first plurality of monochromatic emitters configured to emit a first plurality of light rays corresponding to a plurality of projection planes perceived at different distances; a first plurality of collimating lenses corresponding to the first plurality of monochromatic emitters, each collimating lens being configured to receive a corresponding light ray from another of the first plurality of monochromatic emitters, such that the first plurality of collimating lenses generates a first plurality of collimated light rays to be projected onto an eye to reproduce a plurality of projection images, each of which is perceived on another of the plurality of projection planes; and a scanner trained to receive the first plurality of collimated light rays and to direct the first plurality of collimated light rays according to a scanning pattern in order to reproduce the plurality of projection images to the eye.

[0106] Exemplary embodiment 21, in the image projection system of exemplary embodiment 20, further comprising: a second plurality of monochromatic emitters configured to emit a second plurality of polarized light beams corresponding to the plurality of projection planes; a second plurality of collimating lenses corresponding to the second plurality of monochromatic emitters, each of the second plurality of collimating lenses being configured to receive a corresponding light beam from another of the second plurality of monochromatic emitters, such that the second plurality of collimating lenses generates a second plurality of collimated light beams to be projected onto the eye to reproduce the plurality of projection images, each of which is perceived on another of the plurality of projection planes;and a first beam combiner located at an intersection of the first plurality of collimated light beams and the second plurality of collimated light beams to direct the first plurality of collimated light beams and the second plurality of collimated light beams onto a combined transmit path, the scanner being located on the combined transmit path to receive the first plurality of collimated light beams and the second plurality of collimated light beams and to direct the first plurality of collimated light beams and the second plurality of collimated light beams according to a scanning pattern to reproduce the plurality of projection images onto the eye.

[0107] Exemplary embodiment 22, in the image projection system of exemplary embodiment 21, further comprising: a third plurality of monochromatic emitters configured to emit a third plurality of light rays corresponding to the plurality of projection planes; and a third plurality of collimating lenses corresponding to the third plurality of monochromatic emitters, each of the third plurality of collimating lenses being configured to receive a corresponding light ray from another of the third plurality of monochromatic emitters, such that the third plurality of collimating lenses produces a third plurality of collimated light rays to be projected onto the eye to reproduce the plurality of projection images, each of which is to be perceived in another of the plurality of projection planes;and a second beam combiner, which is arranged at an intersection of the first plurality of collimated light beams, the second plurality of collimated light beams and the third plurality of collimated light beams, to direct the first plurality of collimated light beams, the second plurality of collimated light beams and the third plurality of collimated light beams onto the combined transmit path, and wherein the scanner is arranged on the combined transmit path to receive the first plurality of collimated light beams, the second plurality of collimated light beams and the third plurality of collimated light beams and to direct the first plurality of collimated light beams, the second plurality of collimated light beams and the third plurality of collimated light beams according to the scanning pattern in order to reproduce the plurality of projection images on the eye.;

[0108] Exemplary embodiment 23, in the image projection system of exemplary embodiment 22, further comprising a first plurality of dichroic mirrors configured to direct the first plurality of collimated light rays onto the first beam combiner; a second plurality of dichroic mirrors configured to direct the second plurality of collimated light rays onto the first beam combiner; and a third plurality of dichroic mirrors configured to direct the third plurality of collimated light rays onto the second beam combiner.

[0109] Exemplary embodiment 24, in the image projection system of exemplary embodiment 23, wherein the second beam combiner is arranged on the combined transmission path between the first beam combiner and the scanner.

[0110] Exemplary embodiment 25, in the image projection system of one of the exemplary embodiments 22 to 24, wherein the first plurality of monochromatic transmitters are red light transmitters which transmit to each other at different wavelengths, the second plurality of monochromatic transmitters are blue light transmitters which transmit to each other at different wavelengths, and the third plurality of monochromatic transmitters are green light transmitters which transmit to each other at different wavelengths.

[0111] Exemplary embodiment 26, in the image projection system of one of the exemplary embodiments 21 to 25, further comprising a first plurality of dichroic mirrors configured to direct the first plurality of collimated light rays onto the first beam combiner; and a second plurality of dichroic mirrors configured to direct the second plurality of collimated light rays onto the first beam combiner.

[0112] Exemplary embodiment 27, in the image projection system of one of the exemplary embodiments 20 to 26, further comprising a first plurality of dichroic mirrors configured to direct the first plurality of collimated light beams onto a common transmission path, wherein the first plurality of monochromatic transmitters is configured to transmit essentially the same color of light at different wavelengths to each other.

[0113] Exemplary embodiment 28, in the image projection system of one of the exemplary embodiments 20 to 27, wherein each of the first plurality of monochromatic transmitters is paired with one of the first plurality of collimating lenses to form a pair, such that each pair is separated by a respective minimum distance corresponding to another of the plurality of projection planes, each respective minimum distance being different from the others.

[0114] Exemplary embodiment 29, in the image projection system of one of the exemplary embodiments 20 to 28, wherein each of the first plurality of collimating lenses is either fixed, such that the respective distance is fixed, or movable, such that the respective distance is adjustable.

[0115] Exemplary embodiment 30, in the image projection system of one of the exemplary embodiments 20 to 29, wherein the plurality of projection planes comprises a first projection plane which is projected to optical infinity and a second projection plane which is projected at a predefined distance which is less than optical infinity.

[0116] Exemplary embodiment 31, in the image projection system of exemplary embodiment 30, wherein the optical infinity corresponds to a virtual distance of at least 9.5 meters.

[0117] Exemplary embodiment 32, in the image projection system of one of the exemplary embodiments 20 to 31, wherein the plurality of projection planes comprises a first projection plane which is projected at a first predefined distance and a second projection plane which is projected at a second predefined distance which differs from the first predefined distance.

Claims

[1] A (100; 200) image projection system comprising: a first transmitter (212d) configured to generate first light rays corresponding to a first projection plane and to send the first light rays along a first transmission path; a first collimation lens (213d) arranged on the first transmission path, the first collimation lens being configured to receive the first light rays and to produce first collimated light rays to be projected onto an eye to reproduce a first projection image that is perceived on the first projection plane; a second transmitter (212i) configured to generate second light beams corresponding to a second projection plane different from the first projection plane and to transmit the second light beams along a second transmission path; a second collimating lens (213i) arranged on the second transmitting path, the second collimating lens being configured to receive the second light rays and to produce second collimated light rays to be projected onto the eye to reproduce a second projection image that is perceived on the second projection plane; a first beam combiner (214) arranged at an intersection of the first transmission path and the second transmission path, wherein the first beam combiner is configured to transmit the first collimated light beams and the second collimated light beams on a combined transmission path; and a scanner (225) arranged on the combined transmission path, the scanner being configured to receive the first collimated light beams and the second collimated light beams and to direct the first collimated light beams and the second collimated light beams according to a scanning pattern to reproduce the first projection image and the second projection image to the eye. [2] The image projection system (100; 200) according to claim 1, further comprising: a second beam combiner (130) located between the scanner (225) and the eye, wherein the second beam combiner receives the first collimated light beams and the second collimated light beams and directs the first collimated light beams and the second collimated light beams towards the eye. [3] The image projection system (100; 200) according to claim 1 or 2, wherein: the first collimation lens (213d) is arranged at a first distance (g1) from the first transmitter (212d); and the second collimation lens (213i) is arranged at a second distance (g2) from the second transmitter (212i), which differs from the first distance (g1). [4] The image projection system (100; 200) according to claim 3, wherein: the first collimation lens (213d) is either fixed, such that the first distance (g1) is fixed, or movable, such that the first distance (g1) is adjustable, and the second collimation lens (213i) is either fixed, such that the second distance (g2) is fixed, or movable, such that the second distance (g2) is adjustable. [5] The image projection system (100; 200) according to one of the preceding claims, wherein: the first projection plane is projected into optical infinity, and the second projection plane is projected at a predefined distance that is less than optical infinity. [6] The image projection system (100; 200) according to claim 5, wherein the optical infinity corresponds to a virtual distance of at least 9.5 meters. [7] The image projection system (100; 200) according to one of the preceding claims, wherein: the first projection plane is projected at a first predefined distance, and the second projection plane is projected at a second predefined distance that differs from the first predefined distance. [8] The image projection system (100; 200) according to one of the preceding claims, wherein: the first transmitter is a first red-green-blue, RGB, transmitter, which includes a red light source, a green light source and a blue light source, and the first projection image is a first RGB image, and the second transmitter is a second RGB transmitter, and the second projection image is a second RGB image. [9] The image projection system (100; 200) according to one of the preceding claims, wherein: the first transmitter is a first monochromatic transmitter, and The second transmitter is a second monochromatic transmitter that broadcasts the same color as the first monochromatic transmitter. [10] The image projection system (100; 200) according to one of the preceding claims, wherein the first transmitter and the second transmitter are configured to send the first light rays and the second light rays to reproduce the first projection image and the second projection image simultaneously on the eye. [11] An image projection system (510), comprising: a first plurality of monochromatic transmitters (212rp, 212gp, 212bp) configured to emit first polarized light rays according to a first projection plane; a first plurality of collimating lenses (213rp, 213gp, 213bp) corresponding to the first plurality of monochromatic transmitters, each of the first plurality of collimating lenses being configured to receive a first polarized light beam from another of the first plurality of monochromatic transmitters, such that the first plurality of collimating lenses produces first polarized collimated light beams to be projected onto an eye to reproduce a first projection image perceived on the first projection plane; a second plurality of monochromatic transmitters (212rs, 212gs, 212bs) configured to emit second polarized light beams according to a second projection plane; a second plurality of collimating lenses (213rs, 213gs, 213bs) corresponding to the second plurality of monochromatic emitters, each of the second plurality of collimating lenses being configured to receive a second polarized light beam from another of the second plurality of monochromatic emitters, such that the second plurality of collimating lenses produces second polarized collimated light beams to be projected onto the eye to reproduce a second projection image that is perceived on the second projection plane; a polarizing beam combiner (523) arranged at an intersection of the first polarized collimated light beams and the second polarized collimated light beams to direct the first polarized collimated light beams and the second polarized collimated light beams onto a combined transmission path; and a scanner (225) arranged on the combined transmission path, the scanner being configured to receive the first polarized collimated light beams and the second polarized collimated light beams and to direct the first polarized collimated light beams and the second polarized collimated light beams according to a scanning pattern to reproduce the first projection image and the second projection image to the eye. [12] The image projection system (510) according to claim 11, wherein: The first polarized light rays are p-polarized light rays, and the second polarized light rays are s-polarized light rays. The polarizing beam combiner comprises a first surface at which the p-polarized light rays are received and a second surface at which the s-polarized light rays are received, wherein the polarizing beam combiner is configured to reflect the p-polarized light rays received at the first surface and to transmit the s-polarized light rays received at the second surface, or to reflect the s-polarized light rays received at the second surface and to transmit the p-polarized light rays received at the first surface. [13] The image projection system (510) according to claim 11 or 12, wherein: each of the first plurality of collimating lenses (213rp, 213gp, 213bp) is arranged at a first minimum distance (g2) from a corresponding of the first plurality of monochromatic transmitters (212rp, 212gp, 212bp); and Each of the second plurality of collimating lenses (213rs, 213gs, 213bs) is arranged at a second minimum distance (g1) from a corresponding of the second plurality of monochromatic transmitters (212rs, 212gs, 212bs), wherein the second minimum distance (g1) differs from the first minimum distance (g2). [14] The image projection system (510) according to any one of claims 11 to 13, wherein: the first plurality of monochromatic transmitters includes a first red light transmitter, a first blue light transmitter, a first green light transmitter and the second plural of monochromatic transmitters includes a second red light transmitter, a second blue light transmitter, a second green light transmitter. [15] The image projection system (510) according to claim 14, further comprising: a first plurality of dichroic mirrors (517, 518) configured to direct the first polarized collimated light rays onto the polarizing beam combiner (523); and a second plurality of dichroic mirrors (521, 522) configured to direct the second polarized collimated light rays onto the polarizing beam combiner (523). [16] The image projection system (510) according to any one of claims 11 to 15, further comprising: a further beam combiner (130) which is arranged between the scanner (225) and the eye, wherein the further beam combiner (130) receives the first polarized collimated light beams and the second polarized collimated light beams and directs the first polarized collimated light beams and the second polarized collimated light beams towards the eye. [17] The image projection system (510) according to any one of claims 11 to 16, wherein: the first projection plane is projected into optical infinity, and the second projection plane is projected at a predefined distance that is less than optical infinity. [18] The image projection system (510) according to claim 17, wherein the optical infinity corresponds to a virtual distance of at least 9.5 meters. [19] The image projection system (510) according to any one of claims 11 to 18, wherein: the first projection plane is projected at a first predefined distance, and the second projection plane is projected at a second predefined distance that differs from the first predefined distance. [20] A picture projection system (600), comprising: a first plurality of monochromatic transmitters (212r1, 212r2, 212r3) configured to emit a first plurality of light rays corresponding to a plurality of projection planes perceived at different distances; a first plurality of collimating lenses (213r1, 213r2, 213r3) corresponding to the first plurality of monochromatic emitters (212r1, 212r2, 212r3), each of the first plurality of collimating lenses (213r1, 213r2, 213r3) being configured to receive a corresponding light beam from another of the first plurality of monochromatic emitters (212r1, 212r2, 212r3), such that the first plurality of collimating lenses produces a first plurality of collimated light beams to be projected onto an eye to reproduce a plurality of projection images, each of which is perceived on another of the plurality of projection planes; and a scanner (225) which is configured to receive the first plurality of collimated light rays and to direct the first plurality of collimated light rays according to a scanning pattern in order to reproduce the plurality of projection images on the eye.

Images