CN115145037A - Large-field-angle high-resolution holographic near-to-eye display device and display method based on field-of-view scanning splicing - Google Patents

Large-field-angle high-resolution holographic near-to-eye display device and display method based on field-of-view scanning splicing Download PDF

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CN115145037A
CN115145037A CN202210642142.2A CN202210642142A CN115145037A CN 115145037 A CN115145037 A CN 115145037A CN 202210642142 A CN202210642142 A CN 202210642142A CN 115145037 A CN115145037 A CN 115145037A
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light modulator
spatial light
field
light source
lens
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夏新星
米朋飞
杨馥荣
王维森
孙明
杨帮华
高守玮
郑华东
于瀛洁
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University of Shanghai for Science and Technology
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University of Shanghai for Science and Technology
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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays
    • G02B27/017—Head mounted
    • G02B27/0172—Head mounted characterised by optical features
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays
    • G02B27/0101—Head-up displays characterised by optical features
    • G02B2027/0123—Head-up displays characterised by optical features comprising devices increasing the field of view
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays
    • G02B27/017—Head mounted
    • G02B27/0172—Head mounted characterised by optical features
    • G02B2027/0174—Head mounted characterised by optical features holographic

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  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
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Abstract

The invention provides a large-field-angle high-resolution holographic near-to-eye display device and a display method based on field-of-view scanning splicing. The holographic near-eye display device comprises a point light source, a collimating lens, a reflector rotating system, a beam splitter, a spatial light modulator, a relay optical system and a master controller. Or the system comprises a point light source moving platform, a collimating lens, a platform moving control system, a beam splitter, a spatial light modulator, a relay optical system and a master controller. The invention can change the direction of parallel light incident on the spatial light modulator by rotating the reflector or moving the point light source, so that holograms incident at different angles are accurately converged to the position of human eyes through the relay optical system, the visual angle range and the image resolution of an image to be watched are increased through continuous scanning under the condition of ensuring the exit pupil size to be certain, and the high-resolution holographic near-eye display with a large field angle and a large exit pupil is simultaneously realized by adopting a field angle continuous scanning method.

Description

Large-field-angle high-resolution holographic near-to-eye display device and display method based on field scanning splicing
Technical Field
The invention relates to the technical field of near-eye display, in particular to a large-field-angle high-resolution holographic near-eye display device and a display method based on field scanning splicing.
Background
The traditional three-dimensional display mainly utilizes binocular vision, and is widely applied to industries such as televisions, movies and games. According to the method, the three-dimensional scene is rendered into two slightly different two-dimensional images and projected to the left eye area and the right eye area of a viewer respectively, and the viewer can obtain three-dimensional perception through brain fusion. Binocular vision-based three-dimensional display technologies can provide all of the psychological cues and binocular disparity cues, but it is difficult to present monocular depth cues. Viewing such display devices for a long time may cause visual fatigue, dizziness, and nausea. This discomfort is due to convergence-accommodation conflicts. In recent years, binocular visual display based on human eye tracking provides depth cues such as motion parallax and occlusion change. However, such devices have difficulty providing a perfect focus cue and have limited improvements in the convergence-accommodation conflict. Therefore, convergence-accommodation conflict is a technological bottleneck that needs to be broken through urgently in binocular vision-based three-dimensional display.
The three-dimensional display technology based on holography can fundamentally solve the convergence-adjustment conflict problem. Holographic three-dimensional display is a display mode for realizing three-dimensional scene reconstruction by utilizing wavefront information. By means of wavefront recording, the hologram completely reserves amplitude and phase information of an object to be reconstructed, so that intensity and depth information of a three-dimensional target can be accurately reproduced. In theory, holographic displays can provide all kinds of depth cues, which are considered to be the ultimate implementation of three-dimensional displays, without the convergence-accommodation conflict problem.
With the development of computer technology, the wavefront recording process can be completed by computational holographic simulation. The holographic algorithm is used for realizing wavefront recording, the spatial light modulator is used for realizing wavefront reconstruction, a user can naturally observe the three-dimensional display image content, and the convergence-adjustment conflict problem is fundamentally solved. In the method, dynamic refreshing is realized by virtue of the spatial light modulator, so that dynamic three-dimensional holographic display is realized, the acquisition process of the hologram is not limited by optical experiment conditions, and the recording target can be an actually existing three-dimensional object or a digital three-dimensional model. However, for a near-eye display system based on the principle of computer holography, the spatial bandwidth product of the system is limited in principle, resulting in the mutual restriction of the field angle and the pupil box. Therefore, the large-field-angle high-resolution holographic near-eye display needs to be realized under the condition that the size of the pupil box meets the normal viewing requirement.
Disclosure of Invention
In order to solve the problems in the prior art, the invention aims to overcome the defects in the prior art, and provides a large-field-of-view high-resolution holographic near-eye display device and a display method based on field-of-view scanning splicing, which can realize the scanning expansion of the field of view under the condition of ensuring that the size of an exit pupil is fixed.
In order to achieve the purpose of the invention, the invention adopts the following technical scheme:
a large-field-angle high-resolution holographic near-to-eye display device based on field-of-view scanning splicing comprises a point light source, a collimating lens, a reflector rotating system, a beam splitter, a spatial light modulator, a relay optical system and a master controller, and forms a virtual reality type holographic near-to-eye display device; wherein:
the point light source is used for providing illumination light; the front focal plane of the collimating lens is provided with a point light source for generating wide beam parallel light; the reflector reflects the parallel light and is connected with the reflector rotating system; the reflector rotation control system is used for controlling the reflector to rotate in two dimensions and is connected with the master controller; the beam splitter reflects and irradiates parallel light collimated by the collimating lens to an effective working area of the spatial light modulator; the spatial light modulator is used for carrying out diffraction modulation on the parallel light with different angles irradiated on the spatial light modulator and is connected with the master controller; the relay optical system images the spatial light modulator to the position near the pupils of human eyes, and the spatial light modulator and the pupillary plane of the human eyes are ensured to be basically in a conjugate relation; and the master controller is used for calculating the rotating direction and angle of the reflecting mirror and a corresponding hologram sequence required to be loaded on the spatial light modulator and synchronously controlling the hologram sequence.
Preferably, the device further comprises a light combiner located behind the relay optical system and used for allowing external light to directly penetrate and enter human eyes to form the augmented reality holographic near-eye display device.
Preferably, the point light source is the output end of a fiber coupled laser, or a narrow-bandwidth LED point light source, or an LED point light source plus a narrow-band filter.
Preferably, the collimating lens is a single lens, a double cemented lens or a collimating lens group consisting of a plurality of lenses; coherent light is emitted by the point light source, and after being filtered by the spatial filter, the coherent light is expanded and collimated by the collimating lens to form parallel light of a wide light beam.
Preferably, the reflector is a two-dimensional rotatable reflector or a scanning galvanometer, or a voice coil reflector; the reflecting mirrors are connected with corresponding reflecting mirror rotation control systems and are used for changing the direction of parallel light irradiated on the spatial light modulator.
Preferably, the beam splitter is a flat beam splitter or a block beam splitter prism, and a polarizing plate may be disposed in front of the beam splitter to adjust the polarization state of the light beam to match the spatial light modulator.
Preferably, the spatial light modulator may be a reflective spatial light modulator or a transmissive spatial light modulator.
Preferably, the spatial light modulator may be a phase type spatial light modulator, or an amplitude and phase hybrid type spatial light modulator.
Preferably, the relay optical system is a 4f optical relay system consisting of a first relay lens and a second relay lens, and the spatial light modulator is imaged near the pupil of the human eye.
Preferably, the optical axes of the first relay lens and the second relay lens in the relay optical system coincide, and the back focal point of the first relay lens coincides with the front focal point of the second relay lens. The first relay lens can be a single lens, a double-cemented lens or a lens group consisting of a plurality of lenses; the second relay lens may be a single lens, a doublet lens or a lens group composed of a plurality of lenses.
Preferably, the light combiner is a light combining system composed of a beam splitter and a lens, or a beam splitter and a concave mirror, and may also be a semi-transparent and semi-reflective curved light combiner or a holographic optical element with similar functions.
Preferably, the large-field-of-view high-resolution holographic near-eye display device based on field scanning splicing is characterized in that a second relay optical system is arranged between a second spatial light modulator and a reflector, and the rotation center position of the reflector is conjugated with the second spatial light modulator through the second relay optical system; the second relay optical system is a 4f relay optical system consisting of two lenses or lens groups, and focal positions of the two lenses or lens groups are overlapped.
A large-field-angle high-resolution holographic near-to-eye display device based on field-of-view scanning splicing comprises a point light source moving platform, a collimating lens, a platform moving control system, a beam splitter, a spatial light modulator, a relay optical system and a master controller, and forms a virtual reality type holographic near-to-eye display device, wherein the point light source moving platform is connected with the collimating lens;
the point light source moving platform is used for providing illumination light, comprises a point light source and a moving platform of a fixed point light source, and can control the point light source to move in space; a point light source moving platform is arranged on the front focal plane of the collimating lens and is used for generating wide beam parallel light; the platform movement control system controls a point light source in a point light source movement platform to translate on a front focal plane of the collimating lens so as to generate wide light beam parallel light with different angles, and is connected with the master controller; the beam splitter reflects and irradiates the parallel light collimated by the collimating lens to an effective working area of the spatial light modulator; the spatial light modulator is used for carrying out diffraction modulation on the parallel light with different angles irradiated on the spatial light modulator and is connected with the master controller; the relay optical system images the spatial light modulator to the position near the pupils of human eyes, and the spatial light modulator and the pupillary plane of the human eyes are ensured to be basically in a conjugate relation; and the master controller is used for calculating the moving range of the point light source moving platform and a corresponding hologram sequence required to be loaded on the spatial light modulator and synchronously controlling the hologram sequence.
Preferably, the holographic near-eye display device further comprises a light combiner located behind the relay optical system and used for allowing external light to directly penetrate and enter human eyes, so as to realize the augmented reality holographic near-eye display device.
The invention relates to a large-field-angle high-resolution holographic near-eye display method based on field-view scanning splicing, which is operated by adopting a large-field-angle high-resolution holographic near-eye display device based on field-view scanning splicing and comprises the following operation steps:
the first step is as follows: pupil center position (x) of human eye 0 ,y 0 ) And (4) calculating the rotation angle range (-theta, theta) of the reflector or the movement range (-L, L) of the point light source according to the requirements of the field angle, the resolution ratio and the like of the system, and the sequence number of the loaded holograms.
The second step: and the master controller calculates the corresponding rotation angle of the reflector or the spatial position of the point light source movement according to the field angle scanning step length, loads the corresponding hologram, and correspondingly encodes the hologram according to the type of the spatial light modulator to form a loading and encoding hologram sequence.
The third step: the master controller controls the rotation of the reflector through the reflector rotating system, or controls the movement of the point light source moving platform through the platform moving control system, and controls the spatial light modulator to load a corresponding hologram, and the master controller controls the synchronization of the reflector rotation or the point light source movement and the loading of the hologram through the reflector rotating system or the platform moving control system and the spatial light modulator drive.
The fourth step: according to the conjugate relation of the optical system, the relay optical system images the spatial light modulator to the position near the pupil of the human eye.
The fifth step: the human eyes watch the large-visual-angle high-resolution holographic three-dimensional image spliced by the system through the field angle scanning.
Compared with the prior art, the invention has the following obvious and prominent substantive characteristics and remarkable advantages:
1. the invention provides a large-view-angle high-resolution holographic near-eye display device and a display method based on field-of-view scanning splicing.
2. The method is simple and easy to implement, low in cost and suitable for popularization and application.
Drawings
Fig. 1 is a schematic structural diagram of a virtual reality type large-field-angle high-resolution holographic near-eye display system based on a reflective spatial light modulator according to embodiment 1 of the present invention.
Fig. 2 is a schematic structural diagram of an augmented reality type large-field-angle high-resolution holographic near-eye display system based on a reflective spatial light modulator according to embodiment 2 of the present invention.
Fig. 3 is a schematic structural diagram of a virtual reality type large-field-angle high-resolution holographic near-eye display system based on a transmissive spatial light modulator according to embodiment 3 of the present invention.
Fig. 4 is a schematic structural diagram of a virtual reality type large-field-angle high-resolution holographic near-eye display system based on a reflective spatial light modulator according to embodiment 4 of the present invention.
Fig. 5 is a schematic structural diagram of a virtual reality type large-field-angle high-resolution holographic near-eye display system based on a reflective spatial light modulator according to embodiment 5 of the present invention.
Fig. 6 is a schematic structural diagram of an enhanced real-type large-field-angle high-resolution holographic near-eye display system based on a reflective spatial light modulator according to embodiment 6 of the present invention.
Fig. 7 is a schematic flow chart of a large-field-angle high-resolution holographic near-eye display method for realizing continuous scanning and splicing of a field of view based on mirror rotation, which is provided by embodiments 1, 2, 3, and 4 of the present invention.
Fig. 8 is a schematic flow chart of a large-field-angle high-resolution holographic near-eye display method for realizing field-of-view continuous scanning and splicing based on point light source movement according to embodiments 5 and 6 of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.
The above-described scheme is further illustrated below with reference to specific embodiments, which are detailed below:
example 1
The embodiment is applied to an embodiment of a virtual reality type large-field-angle high-resolution holographic near-eye display device, and as shown in fig. 1, the holographic near-eye display device includes a point light source 100, a collimating lens 110, a mirror 120, a mirror rotating system 130, a beam splitter 140, a spatial light modulator 150, a relay optical system 160, and a total controller 170.
The point light source 100 is used to provide illumination light, and the point light source is a coherent light source, and is generally output by a laser, or output by a broad spectrum light source plus a narrow band filter. The point light source 100 may be an output end of a fiber coupled laser, or an LED point light source with a narrow bandwidth, or an LED point light source plus a narrow band filter.
The front focal plane of the collimating lens 110 is provided with a point light source 100, and the lens 110 collimates the light beam emitted by the point light source 100 to generate wide beam parallel light. The collimating lens 110 may be a single lens, a double cemented lens or a collimating lens group composed of a plurality of lenses; coherent light is output by the point light source 100, filtered by the spatial filter, and expanded and collimated by the collimating lens 100 to form parallel light of a wide light beam.
The mirror 120 is mainly used to reflect the collimated parallel light through the beam splitter 140 and then illuminate the spatial light modulator 150. The position of the mirror is not fixed but is rotated in two dimensions (along the X-axis, along the Y-axis) based on an initial position determined according to the actual requirements of the system. The rotation direction and rotation angle of the mirror 120 are controlled by the mirror rotation system 130 according to the system operation requirements. The reflector 120 may be a flat reflector or a curved reflector.
The mirror rotation control system 130 is composed of a mirror rotation driver 131 and an execution rotation device 132, and the mirror rotation control system 130 is connected to the mirror 120 for controlling the mirror 120 to rotate in two dimensions, so as to change the angle of the parallel light irradiated onto the spatial light modulator 150. The reflecting mirror 120 can be installed on a two-degree-of-freedom rotating platform, so as to ensure that the front surface of the reflecting mirror coincides with the rotation center, and the driving is controlled by a reflecting mirror rotating driver 131. The reflecting mirror 120 may also be a two-dimensional scanning galvanometer, a mirror plate of the two-dimensional scanning galvanometer is connected with a scanning motor, and the scanning motor is generally a stepping motor or a servo motor and is controlled and driven by a reflecting mirror rotating driver 131. The mirror 120 may be a biaxial voice coil mirror, and the mirror is driven by a voice coil motor to rotate, and the rotation center of the mirror coincides with the front surface of the mirror, and is controlled and driven by a mirror rotation driver 131.
The beam splitter 140 reflects the wide beam of parallel light reflected by the mirror 120 to the spatial light modulator 150 and covers the effective working area of the spatial light modulator 150; the beam splitter 140 is a flat beam splitter or a block beam splitter prism, and a polarizer may also be disposed in front of the beam splitter 140 to adjust the polarization state of the light beam to match with the spatial light modulator 150.
The spatial light modulator 150 loads a computed hologram with a corresponding field angle according to the angle of the parallel light impinging thereon. The angle of the parallel light irradiated on the spatial light modulator 150 is changed by controlling the two-dimensional rotation of the mirror 120, the wide-beam parallel light with different angles is respectively irradiated on the spatial light modulator 150, the irradiated common area is a hologram loading area (effective working area) of the spatial light modulator 150, the spatial light modulator 150 performs diffraction modulation on the parallel light irradiated thereon, and the light beam after the diffraction modulation is converged to an exit pupil position through the relay optical system 160 to provide a three-dimensional image for human eyes. The spatial light modulator 150 is connected to the general controller 170, and is mainly used for controlling the display image, the display frame rate, the resolution and the like of the spatial light modulator 150; the spatial light modulator 150 may be a phase type, amplitude type, or amplitude and phase hybrid type spatial light modulator.
The relay optical system 160 is an imaging system composed of a first relay lens 161 and a second relay lens 162, and ensures that the effective working area of the spatial light modulator 150 and the system exit pupil (pupil surface of human eye) are basically in conjugate relation, and certain deviation can be allowed. The basic structure of the relay optical system 160 is a 4f optical system, the optical axes of the first relay lens 161 and the second relay lens 162 coincide, and the back focal point of the first relay lens 161 coincides with the front focal point of the second relay lens 162. The relay optical system 160 images the effective working area of the spatial light modulator 150 to the vicinity of the pupil of the human eye according to the system conjugate relationship. The focal length of the first relay lens 161 and the focal length of the second relay lens 162 are determined by the size relationship of both the effective working area of the spatial light modulator 150 and the system exit pupil (human eye pupil). The relay optical system 160 propagates the diffracted beam with image information to an exit pupil location to provide a three-dimensional image to the human eye. The angle of the parallel light irradiated on the spatial light modulator 150 is changed by controlling the two-dimensional rotation of the mirror 120, the wide-beam parallel light with different angles respectively covers the effective working area on the spatial light modulator 150, and the image is formed through the relay optical system 140 to form holographic three-dimensional images with different viewing angle directions for human eyes to watch. The first relay lens 141 may be a single lens, a double cemented lens or a lens group composed of a plurality of lenses. The second relay lens 142 may be a single lens, a double cemented lens or a lens group composed of a plurality of lenses.
On one hand, the general controller 170 calculates the corresponding rotation angle of the mirror according to the field angle scanning step length, and then controls the rotation of the mirror 120 through the mirror rotation control system 130, so as to irradiate the wide-beam parallel light with different angles onto the spatial light modulator 150, and image the spatial light modulator 150 near the pupil of the human eye through the relay optical system 160, thereby providing the holographic three-dimensional image with different view angle directions for the human eye. On the other hand, the overall controller 170 encodes a corresponding hologram according to the image to be displayed and loads the hologram onto the spatial light modulator 150 to allow the human eye to see the corresponding three-dimensional image.
The point light source 100 provides illumination light, and the collimating lens 110 collimates the light beam emitted by the point light source 100 to generate wide light beam parallel light; the generated wide-beam parallel light is reflected by the rotating mirror 120 to form wide-beam parallel light with different angles, and is reflected by the beam splitter 140 to irradiate the spatial light modulator 150 and cover the effective working area of the spatial light modulator 150. The parallel light in different directions is subjected to phase, amplitude or complex amplitude diffraction modulation by the spatial light modulator 150, then passes through the beam splitter, and then is converged near the pupil of the human eye by the relay optical system 160, so as to provide the holographic three-dimensional image in different view angle directions for the human eye. The system realizes continuous scanning to expand the field angle through the rotating reflector, and finally forms the holographic near-to-eye display with large field angle and high resolution. The continuous scanning mode completes the expansion of the viewing field angle under the condition of ensuring that the size of the system exit pupil meets the requirement of the pupil (generally equivalent to the size of the pupil, namely 3mm to 5 mm), thereby realizing the high-resolution holographic near-eye display with a large field angle and a large exit pupil.
Example 2
The embodiment is used for an embodiment of an augmented reality type large-field-angle high-resolution holographic near-eye display device based on field-of-view scanning stitching, and as shown in fig. 2, the holographic near-eye display device includes a point light source 100, a collimating lens 110, a mirror 120, a mirror rotating system 130, a beam splitter 140, a spatial light modulator 150, a relay optical system 160, a total controller 170, and a light combiner 180.
The light combiner 180 is located behind the relay optical system 160, and is configured to allow external light to directly penetrate into the human eye, and to allow the reflected light diffracted and modulated by the spatial light modulator 150 to converge into the human eye, so that the human eye can see both an external real environment and a virtual image, and an augmented reality type holographic near-to-eye display is implemented; the light combiner 180 may be a beam splitter and a lens, or a light combining system composed of a beam splitter and a concave mirror, or a single semi-transparent and semi-reflective curved light combiner, or a holographic optical element with similar functions.
The point light source 100 provides illumination light, and the collimating lens 110 collimates the light beam emitted by the point light source 100 to generate wide light beam parallel light; the generated wide-beam parallel light is reflected by the rotating mirror 120 to form wide-beam parallel light with different angles, and is reflected by the beam splitter 140 to irradiate the spatial light modulator 150 and cover the effective working area of the spatial light modulator 150. Parallel light in different directions passes through the spatial light modulator 150, is subjected to phase, amplitude or complex amplitude diffraction modulation, then passes through the beam splitter, and then reaches the light combiner 180 after being imaged by the relay optical system 160, the light combiner 180 reflects light beams with image information to enter human eyes, and simultaneously external light beams are directly transmitted to enter the human eyes, so that the human eyes can see both an external real environment and a virtual image, and the augmented reality type holographic near-to-eye display is realized. On one hand, the general controller 170 calculates the corresponding rotation angle of the mirror according to the field angle scanning step length, and then controls the rotation of the mirror 120 through the mirror rotation control system 130; on the other hand, the corresponding hologram is encoded according to the image to be displayed and loaded onto the spatial light modulator 150, allowing the human eye to see the corresponding three-dimensional image. The system realizes the expansion of the field angle through continuous scanning by rotating the reflector, and finally forms the augmented reality type holographic near-eye display with large field angle and high resolution. The continuous scanning mode completes the expansion of the viewing field angle under the condition of ensuring that the size of the system exit pupil meets the requirement of the pupil (generally, the size is equivalent to the size of the pupil, and is about 3mm to 5 mm), thereby realizing the high-resolution holographic near-eye display with a large field angle and a large exit pupil.
Example 3
The embodiment is applied to an embodiment of a virtual reality type large-field-angle high-resolution holographic near-eye display device, which includes a point light source 100, a collimating lens 110, a mirror 120, a mirror rotating system 130, a beam splitter 140, a spatial light modulator 350, a relay optical system 160, and a total controller 170, as shown in fig. 3.
The spatial light modulator 350 is a transmissive spatial light modulator, and a computed hologram with a corresponding field angle is loaded according to an angle of parallel light irradiated thereon. The angle of the parallel light irradiated on the spatial light modulator 350 is changed by controlling the two-dimensional rotation of the mirror 120, the wide-beam parallel light with different angles is respectively irradiated on the spatial light modulator 350, the irradiated common area is a hologram loading area (effective working area) of the spatial light modulator 350, and after being subjected to phase, amplitude or complex amplitude diffraction modulation by the transmission type spatial light modulator 350, the hologram loading area is transmitted to the relay optical system 160, and is imaged to the vicinity of the pupil of the human eye by the relay optical system 160 so that the human eye can watch a three-dimensional image. The spatial light modulator 350 is connected to the general controller 170, and is mainly used for controlling the display image, the display frame rate, the resolution, and the like of the spatial light modulator 350; the spatial light modulator 350 may be a phase type, amplitude type, or amplitude and phase hybrid spatial light modulator.
The point light source 100 provides illumination light, and the collimating lens 110 collimates the light beam emitted by the point light source 100 to generate wide light beam parallel light; the generated wide-beam parallel light is reflected by the rotating mirror 120 to form wide-beam parallel light with different angles, and the wide-beam parallel light directly irradiates the spatial light modulator 350 and covers the effective working area of the spatial light modulator 350. The parallel light beams in different directions are subjected to phase, amplitude or complex amplitude diffraction modulation by the spatial light modulator 350, then transmitted to the relay optical system 160, and converged near the pupil of the human eye by the relay optical system 160, so as to provide a holographic three-dimensional image in different view angle directions for the human eye. On one hand, the general controller 170 calculates the corresponding rotation angle of the mirror according to the field angle scanning step length, and then controls the rotation of the mirror 120 through the mirror rotation control system 130; on the other hand, the corresponding hologram is encoded according to the image to be displayed and loaded onto the spatial light modulator 350, allowing the human eye to see the corresponding three-dimensional image. The system realizes the expansion of the field angle through continuous scanning by rotating the reflector, and finally forms the augmented reality type holographic near-eye display with large field angle and high resolution. The continuous scanning mode completes the expansion of the viewing field angle under the condition of ensuring that the size of the system exit pupil meets the requirement of the pupil (generally, the size is equivalent to the size of the pupil, and is about 3mm to 5 mm), thereby realizing the high-resolution holographic near-eye display with a large field angle and a large exit pupil.
Fig. 3 only illustrates an embodiment of implementing a virtual reality type holographic near-eye display device by using the transmissive spatial light modulator 350, and an augmented reality type holographic near-eye display device can also be implemented by using the transmissive spatial light modulator 350 in combination with the embodiment 2. The light combiner 180 is arranged behind the relay optical system 160, and the light beam with the image information is reflected by the light combiner 180 to enter human eyes, and meanwhile, external light beams are directly transmitted to enter the human eyes, so that the human eyes can see both the external real environment and the virtual image, and the augmented reality type holographic near-to-eye display is realized.
Example 4
The embodiment is applied to an embodiment of a virtual reality type large-field-angle high-resolution holographic near-eye display device, and as shown in fig. 4, the holographic near-eye display device includes a point light source 100, a collimating lens 110, a reflecting mirror 120, a mirror rotating system 130, a first beam splitter 440, a second relay optical system 450, a second beam splitter 460, a second spatial light modulator 470, a second relay optical system 480, and a total controller 170.
The point light source 100 is used to provide illumination light, and the point light source is a coherent light source, and is generally output by a laser, or output by a broad spectrum light source plus a narrow band filter. The point light source 100 may be the output end of a fiber coupled laser, a narrow-band LED point light source, or an LED point light source plus a narrow-band filter.
The front focal plane of the collimating lens 110 is provided with a point light source 100, and the lens 110 collimates the light beam emitted by the point light source 100 to generate wide beam parallel light. The collimating lens 110 may be a single lens, a double cemented lens or a collimating lens group composed of a plurality of lenses. The collimating lens 110 may also be a beam expanding collimating system, and coherent light is output from the point light source 100, and after being filtered by the spatial filter, the coherent light is expanded and collimated to form parallel light of a wide light beam.
The mirror 120 is mainly used to reflect the collimated parallel light through the first beam splitter 440 and the second relay optical system 450 to illuminate the second spatial light modulator 470. The position of the mirror is not fixed but is rotated in two dimensions (along the X-axis, along the Y-axis) based on an initial position determined according to the actual requirements of the system. The rotation direction and rotation angle of the mirror 120 are controlled by the mirror rotation system 130 according to the system operation requirements. The reflector 120 may be a flat reflector or a curved reflector.
The mirror rotation control system 130 is composed of a mirror rotation driver 131 and an execution rotation device 132, and the mirror rotation control system 130 is connected to the mirror 120 for controlling the mirror 120 to perform two-dimensional rotation, so as to change the angle of the parallel light irradiated onto the second spatial light modulator 470. The reflecting mirror 120 can be installed on a two-degree-of-freedom rotating platform, so as to ensure that the front surface of the reflecting mirror coincides with the rotation center, and the driving is controlled by a reflecting mirror rotating driver 131. The reflecting mirror 120 may also be a two-dimensional scanning galvanometer, a mirror plate of the two-dimensional scanning galvanometer is connected with a scanning motor, and the scanning motor is generally a stepping motor or a servo motor and is controlled and driven by a reflecting mirror rotating driver 131. The mirror 120 may be a biaxial voice coil mirror, and the mirror is driven by a voice coil motor to rotate, and the rotation center of the mirror coincides with the front surface of the mirror, and is controlled and driven by a mirror rotation driver 131.
The first beam splitter 440 is used to reflect the parallel light to the mirror 120 and transmit the parallel light reflected by the mirror to the second relay optical system 450. The first beam splitter 440 may be a beam splitter prism or a flat plate beam splitter.
The second relay optical system 450 is an imaging system composed of a first relay lens 451 and a second relay lens 452, and ensures that the central position of the reflector 120 and the second spatial light modulator 470 form a conjugate relationship, so as to collect light and make full use of energy. The basic structure of the second relay optical system 450 may be a 4f optical system, which is composed of two first and second relay lenses 451, 452 having the same focal length f, the optical axes of the first and second relay lenses 451, 452 coinciding, and the back focal point of the first relay lens 451 coinciding with the front focal point of the second relay lens 452. The second relay optical system 450 may also be a modified 4f optical system, which is composed of a first relay lens 451 with a first focal length f1 and a second relay lens 452 with a second focal length f2, and is used to enlarge or reduce the size of the light beam irradiated onto the second spatial light modulator 470, so as to ensure the full utilization of the illumination light energy and make the spatial layout of the system more reasonable. The first relay lens 451 may be a single lens, a double cemented lens or a lens group composed of a plurality of lenses. The second relay lens 452 may be a single lens, a double cemented lens or a lens assembly composed of a plurality of lenses.
The second beam splitter 460 is configured to reflect the parallel light to the second spatial light modulator 470, and transmit the diffracted light modulated by the second spatial light modulator 470 to the second relay optical system 480. The second beam splitter 460 may be a beam splitter prism or a flat-panel beam splitter, and a polarizer may be disposed in front of the second beam splitter 460 to adjust the polarization state of the light beam to match the spatial light modulator.
The second spatial light modulator 470 loads a computed hologram of a corresponding field angle according to the angle of the parallel light impinging thereon. By controlling the two-dimensional rotation of the mirror 120, the angle of the parallel light irradiated on the second spatial light modulator 470 is changed, the wide-beam parallel light with different angles is respectively irradiated on the second spatial light modulator 470, the irradiated common area is a hologram loading area (effective working area) of the second spatial light modulator 470, the second spatial light modulator 470 performs diffraction modulation on the parallel light irradiated thereon, and the light beam after diffraction modulation is converged to the exit pupil position by the second relay optical system 480 to provide a three-dimensional image for human eyes. The second spatial light modulator 470 is connected to the general controller 170, and is mainly used for controlling the display image, the display frame rate, the resolution, and the like of the second spatial light modulator 470; the second spatial light modulator 470 may be a phase type, amplitude type, or amplitude phase hybrid spatial light modulator.
The second relay optical system 480 is an imaging system composed of a third relay lens 481 and a fourth relay lens 482, and ensures that the effective working area of the second spatial light modulator 470 and the system exit pupil (pupil surface of human eye) are basically in a conjugate relationship, and a certain deviation can be allowed. The basic structure of the second relay optical system 480 is a 4f optical system, the optical axes of the third relay lens 481 and the fourth relay lens 482 coincide, and the back focus of the third relay lens 481 coincides with the front focus of the fourth relay lens 482. The second relay optical system 480 images the working area of the second spatial light modulator 470 near the pupil of the human eye according to the system conjugate relationship. The focal length of the first relay lens 481 and the focal length of the second relay lens 482 are determined by the dimensional relationship of both the operating region of the second spatial light modulator 470 and the system exit pupil (human eye pupil). The second relay optical system 480 propagates the diffracted light beam with image information to the exit pupil position to provide a three-dimensional image for the human eye. The angle of the parallel light irradiated onto the second spatial light modulator 470 is changed by controlling the two-dimensional rotation of the mirror 120, the wide-beam parallel light with different angles respectively covers the effective working area on the second spatial light modulator 470, and is imaged by the second relay optical system 480 to form a holographic three-dimensional image with different viewing angle directions for human eyes to watch. The third relay lens 481 may be a single lens, a double cemented lens, or a lens group composed of a plurality of lenses. The fourth relay lens 482 may be a single lens, a double cemented lens, or a lens group composed of a plurality of lenses.
On one hand, the general controller 170 calculates the corresponding rotation angle of the reflector according to the field angle scanning step length, and then controls the rotation of the reflector 120 through the reflector rotation control system 130, so that the wide-beam parallel light with different angles is irradiated onto the second spatial light modulator 470 through the system, and the second spatial light modulator 470 is imaged near the pupil of the human eye through the second relay optical system 480, thereby providing the holographic three-dimensional image with different view angle directions for the human eye. On the other hand, the overall controller 170 encodes a corresponding hologram according to the image to be displayed and loads the hologram onto the second spatial light modulator 470 to allow the human eye to see the corresponding three-dimensional image.
The point light source 100 provides illumination light, and the collimating lens 110 collimates the light beam emitted by the point light source 100 to generate wide light beam parallel light; the wide beam parallel light is reflected to the reflecting mirror 120 through the first beam splitter 440, the wide beam parallel light in different directions is generated by controlling the rotation of the reflecting mirror 120, and is irradiated onto the second spatial light modulator 470 through the second relay optical system 450 and the second beam splitter 460, the parallel light in different directions is subjected to phase, amplitude or complex amplitude diffraction modulation through the second spatial light modulator 470, then passes through the second beam splitter 460, and is converged near the pupil of the human eye through the second relay optical system 480, so as to provide a holographic three-dimensional image in different view angle directions for the human eye. The system realizes continuous scanning to expand the field angle through the rotating reflector, and finally forms the holographic near-to-eye display with large field angle and high resolution. The continuous scanning mode completes the expansion of the viewing field angle under the condition of ensuring that the size of the system exit pupil meets the requirement of the pupil (generally equal to the size of the pupil, namely 3mm to 5 mm), thereby realizing the high-resolution holographic near-eye display with a large field angle and a large exit pupil.
Fig. 4 only illustrates one embodiment of implementing a virtual reality type holographic near-eye display device, and an augmented reality type holographic near-eye display device may also be implemented in combination with the embodiment 2. The light combiner 180 is arranged behind the second relay optical system 480, and the light combiner 180 reflects the light beam with the image information into human eyes, and simultaneously enables the external light beam to directly transmit into the human eyes, so that the human eyes can see both the external real environment and the virtual image, and the augmented reality type holographic near-to-eye display is realized.
Example 5
The embodiment is applied to an embodiment of a virtual reality type large-field-angle high-resolution holographic near-eye display device, and as shown in fig. 5, the holographic near-eye display device includes a point light source moving platform 500, a collimating lens 510, a platform movement control system 530, a beam splitter 540, a spatial light modulator 550, a relay optical system 560, and a total controller 570.
The point light source moving platform 500 is composed of a point light source 501 and a two-dimensional moving platform 502, wherein the point light source 501 is installed on the two-dimensional moving platform 502. The position of the point light source 501 is not fixed, but is translated in two dimensions (along the X-axis and along the Y-axis) based on an initial position, which is determined according to the actual requirements of the system. The translation direction and the translation distance of the point light source 501 are controlled by the point light source movement control system 530 according to the system operation requirements. The point light source 501 may be the output end of a fiber coupled laser, a narrow-band LED point light source, or an LED point light source plus a narrow-band filter.
The front focal plane of the collimating lens 510 is provided with a point light source moving platform 500, the divergence angle of the light source of the point light source 501 in the point light source moving platform 500 is large enough, and the lens 510 collimates the light beam emitted by the point light source 501 to generate wide light beam parallel light. The collimating lens 510 may be a single lens, a double cemented lens or a collimating lens group composed of a plurality of lenses.
The point light source movement control system 530, which is composed of a moving platform driving motor 531 and a point light source movement driver 532, is connected to the point light source moving platform 500 and is used to control the two-dimensional movement of the point light source 501, thereby changing the direction of the wide beam of parallel light rays irradiated onto the spatial light modulator 550. The moving platform driving motor 531 is generally a stepping motor or a servo motor, and is controlled and driven by the point light source moving driver 532. The point light source moving driver 532 is connected to the overall controller 570.
The beam splitter 540 reflects the wide beam of parallel light collimated by the collimating lens 510 to the spatial light modulator 550 and covers the effective working area of the spatial light modulator 550; the beam splitter 540 is a flat beam splitter or a block beam splitter prism, and a polarizer may be disposed in front of the beam splitter 540 for adjusting the polarization state of the light beam to match with the spatial light modulator 550.
The spatial light modulator 550 loads a computed hologram of a corresponding field angle according to the angle of the parallel light impinging thereon. The angle of parallel light irradiated on the spatial light modulator 550 is changed by controlling the two-dimensional translation of the point light source moving platform 500, wide beams of parallel light of different angles are respectively irradiated on the spatial light modulator 550, the irradiated common area is a hologram loading area (effective working area) of the spatial light modulator 550, the spatial light modulator 550 performs diffraction modulation on the parallel light irradiated thereon, and the light beam after the diffraction modulation is converged to an exit pupil position through the relay optical system 560 to provide a three-dimensional image for human eyes. The spatial light modulator 550 is connected to the general controller 570, and is mainly used for controlling the display image, the display frame rate, the resolution, and the like of the spatial light modulator 550; the spatial light modulator 550 may be a phase type, amplitude type, or amplitude and phase mixed type spatial light modulator.
The relay optical system 560 is an imaging system composed of a first relay lens 561 and a second relay lens 562, and ensures that the effective working area of the spatial light modulator 550 and the system exit pupil (pupil surface of human eye) are basically in conjugate relation, and certain deviation can be allowed. The basic configuration of the relay optical system 560 is a 4f optical system, and the optical axes of the first relay lens 561 and the second relay lens 562 coincide with each other, and the back focus of the first relay lens 561 coincides with the front focus of the second relay lens 562. Relay optics 560 images the effective working area of spatial light modulator 550 near the pupil of the human eye according to a system conjugate relationship. The focal length of the first relay lens 561 and the focal length of the second relay lens 562 are determined by the size relationship between the effective working area of the spatial light modulator 550 and the system exit pupil (pupil of human eye). Relay optics 560 propagates the diffracted beam with image information to an exit pupil location to provide a three-dimensional image to the human eye. The angle of parallel light irradiated on the spatial light modulator 550 is changed by controlling the two-dimensional translation of the point light source moving platform 500, wide beams of parallel light at different angles respectively cover the effective working area on the spatial light modulator 550, and holographic three-dimensional images in different viewing angle directions are formed for human eyes to watch through imaging of the relay optical system 560. The first relay lens 561 may be a single lens, a double cemented lens, or a lens group composed of a plurality of lenses. The second relay lens 562 may be a single lens, a double cemented lens or a lens assembly composed of a plurality of lenses.
On one hand, the master controller 570 calculates the spatial position of the point light source according to the field angle scanning step length, and then controls the translation of the point light source moving platform 500 through the platform moving control system 530, so as to irradiate wide-beam parallel light at different angles onto the spatial light modulator 550, and image the spatial light modulator 550 near the pupil of the human eye through the relay optical system 560, thereby providing holographic three-dimensional images at different view angle directions for the human eye. On the other hand, the overall controller 570 encodes the corresponding hologram according to the image to be displayed and loads the hologram onto the spatial light modulator 550, so that the human eye sees the corresponding three-dimensional image.
The point light source 501 is mounted on the two-dimensional moving platform 502 and used for providing illumination light, and the collimating lens 510 collimates the light beam emitted by the point light source 501 to generate wide light beam parallel light; the translation of the point light source moving platform 500 is controlled by the platform moving control system 530, so that wide beam parallel lights with different angles are generated, reflected by the beam splitter 540 and irradiated onto the spatial light modulator 550, and the effective working area of the spatial light modulator 550 is covered. The parallel light in different directions is subjected to phase, amplitude or complex amplitude diffraction modulation by the spatial light modulator 550, then passes through the beam splitter, and then is converged near the pupil of the human eye by the relay optical system 560, so as to provide holographic three-dimensional images in different view angle directions for the human eye. The system realizes continuous scanning to expand the field angle by moving the point light source, and finally forms large-field-angle and high-resolution holographic near-to-eye display. The continuous scanning mode completes the expansion of the viewing field angle under the condition of ensuring that the size of the system exit pupil meets the requirement of the pupil (generally, the size is equivalent to the size of the pupil, and is about 3mm to 5 mm), thereby realizing the high-resolution holographic near-eye display with a large field angle and a large exit pupil.
Fig. 5 illustrates only one embodiment of implementing a virtual reality type holographic near-eye display device using a reflective spatial light modulator 550, and a transmissive spatial light modulator may also be used to implement a virtual reality type holographic near-eye display device in combination with the embodiment 3.
Example 6
The embodiment is used for an embodiment of an augmented reality type large-field-angle high-resolution holographic near-eye display device, and as shown in fig. 6, the holographic near-eye display device includes a point light source moving platform 500, a collimating lens 510, a platform movement control system 530, a beam splitter 540, a spatial light modulator 550, a relay optical system 560, a total controller 570, and a light combiner 580.
The light combiner 580 is located behind the relay optical system 560, and is configured to allow external light to directly penetrate through and enter the human eye, and allow the reflected light diffracted and modulated by the spatial light modulator 150 to converge to enter the human eye, so that the human eye can see both an external real environment and a virtual image, and implement augmented reality type holographic near-to-eye display; the light combiner 580 may be a beam splitter and a lens, or a light combining system composed of a beam splitter and a concave mirror, or a single semi-transparent and semi-reflective curved light combiner, or a holographic optical element with similar functions.
The point light source 501 is installed on the two-dimensional mobile platform 502 and used for providing illumination light, and the collimating lens 510 collimates the light beam emitted by the point light source 501 to generate wide-beam parallel light; the translation of the point light source moving platform 500 is controlled by the platform movement control system 530, so that wide-beam parallel light beams with different angles are generated, reflected by the beam splitter 540 and irradiated onto the spatial light modulator 550, and the effective working area of the spatial light modulator 550 is covered. Parallel light in different directions passes through the spatial light modulator 550, is subjected to phase, amplitude or complex amplitude diffraction modulation, then penetrates through the beam splitter, and then reaches the light combiner 580 after being imaged by the relay optical system 560, the light combiner 580 reflects a light beam with image information to enter human eyes, and simultaneously, external light beams are directly transmitted to enter the human eyes, so that the human eyes can see both an external real environment and a virtual image, and the reality-enhanced holographic near-to-eye display is realized. The system realizes the expansion of the field angle by moving the point light source to realize continuous scanning, and finally forms the holographic near-to-eye display with large field angle and high resolution. The continuous scanning mode completes the expansion of the viewing field angle under the condition of ensuring that the size of the system exit pupil meets the requirement of the pupil (generally, the size is equivalent to the size of the pupil, and is about 3mm to 5 mm), thereby realizing the high-resolution holographic near-eye display with a large field angle and a large exit pupil.
Fig. 6 illustrates only one embodiment of implementing the augmented reality type holographic near-eye display device by using the reflective spatial light modulator 550, and the augmented reality type holographic near-eye display device can also be implemented by using the transmissive spatial light modulator in combination with the embodiment 2.
Example 7
A schematic flow chart of the large-field-angle high-resolution holographic near-eye display method for realizing continuous field-of-view scanning based on mirror rotation provided in this embodiment is shown in fig. 7, and the method includes the following operation steps:
the first step is as follows: pupil center position (x) of human eye 0 ,y 0 ) And (4) calculating the rotation angle range (-theta, theta) of the reflector and the sequence number of the loaded holograms according to the requirements of the field angle, the resolution ratio and the like of the system. (same range around x-axis and around y-axis)
The second step is that: and the master controller calculates the corresponding rotation angle of the reflector according to the field angle scanning step length, loads the corresponding hologram, and correspondingly encodes the hologram according to the type of the spatial light modulator to form a loaded encoded hologram sequence. In this embodiment, since the spatial light modulator has three modulation methods of amplitude, phase, and complex amplitude modulation, encoding of the hologram can be performed by amplitude encoding, phase encoding, and complex amplitude encoding according to the type of the spatial light modulator. The hologram generating and encoding process is as follows:
1. according to a three-dimensional scene to be displayed, calculating the complex amplitude distribution U of the exit pupil position by a point source method, an angular spectrum method, fresnel diffraction, freon and Fisher diffraction method and the like i ；
2. Complex amplitude distribution U from exit pupil position i Calculating the complex amplitude distribution U of the spatial light modulator surface slm ；
3. Distributing the complex amplitude of the spatial light modulator surface U slm And encoding the holographic image information H into corresponding loading holographic image information H of the spatial light modulator according to different modulation modes of the spatial light modulator.
The third step: the master controller controls the rotation of the reflector through the reflector rotation system and controls the spatial light modulator to load a corresponding hologram. The rotation of the mirror is continuous, so the field angle achieves continuous scanning, and a higher resolution effect can be formed with partially overlapping images. The rotation of the reflector controlled by the reflector rotation system and the loading of the corresponding hologram controlled by the spatial light modulator driven by the spatial light modulator are synchronously performed under the control of the master controller.
The fourth step: according to the conjugate relation of the optical system, the relay optical system images the spatial light modulator to the position near the pupil of the human eye.
The fifth step: human eyes watch the large-view-angle high-resolution holographic three-dimensional image spliced by the system through field angle scanning.
Example 8
The schematic flow chart of the large-field-angle high-resolution holographic near-eye display method for realizing continuous field-of-view scanning based on point light source movement provided by the embodiment is as shown in fig. 8, and the method includes the following operation steps:
the first step is as follows: pupil center position (x) of human eye 0 ,y 0 ) And (4) calculating the moving range (-L, L) of the point light source and the sequence number of the loaded holograms according to the requirements of the field angle, the resolution ratio and the like of the system. (same range along x-axis and around y-axis)
The second step is that: and the master controller calculates the moving spatial position of the point light source according to the field angle scanning step length, loads a corresponding hologram, and correspondingly encodes the hologram according to the type of the spatial light modulator to form a loading and encoding hologram sequence. In this embodiment, since the spatial light modulator has three modulation methods of amplitude, phase, and complex amplitude modulation, the hologram encoding can be performed by amplitude encoding, phase encoding, and complex amplitude encoding according to the type of the spatial light modulator. The hologram generation and encoding process is as follows:
1. according to a three-dimensional scene to be displayed, calculating the complex amplitude distribution U of the exit pupil position by a point source method, an angular spectrum method, fresnel diffraction, freon and Fisher diffraction method and the like i ；
2. Complex amplitude distribution U from exit pupil position i Calculating the complex vibration of the spatial light modulator surfaceBreadth distribution U slm ；
3. Distributing the complex amplitude of the spatial light modulator surface U slm And encoding the information into corresponding loading holographic image information H of the spatial light modulator according to different modulation modes of the spatial light modulator.
The third step: the master controller controls the point light source moving platform to move through the platform moving control system and loads the corresponding hologram through controlling the spatial light modulator. The movement of the point light source is continuous, so the field angle achieves continuous scanning, and a higher resolution effect can be formed with partially overlapped images. The platform movement control system controls the point light source moving platform to move and the spatial light modulator drives and controls the spatial light modulator to load the corresponding hologram synchronously under the control of the master controller.
The fourth step: according to the conjugate relation of the optical system, the relay optical system images the spatial light modulator to the position near the pupil of the human eye.
The fifth step: human eyes watch the large-view-angle high-resolution holographic three-dimensional image spliced by the system through field angle scanning.
In summary, the embodiment is based on the field-of-view scanning large-field-angle high-resolution holographic near-eye display device and the display method. Embodiments 1, 2, 3, 4, and 7 are large-field-angle high-resolution holographic near-eye display devices and display methods that implement field-of-view scanning based on mirror rotation, where the holographic near-eye display devices include a point light source, a collimating lens, a mirror rotation system, a beam splitter, a spatial light modulator, a relay optical system, and a master controller. The light emitted by the point light source is collimated by the lens and then irradiates onto the reflecting mirror, the reflecting mirror reflects the light onto the beam splitter, the parallel light is reflected by the beam splitter and irradiates onto the spatial light modulator, the parallel light is modulated and diffracted by the calculation hologram loaded on the spatial light modulator, and the diffracted image light is converged to the exit pupil position through the relay optical system to be watched by human eyes. The controller is used for calculating the rotation angle and direction of the reflector and corresponding holograms loaded on the spatial light modulator, the direction of parallel light incident on the spatial light modulator can be changed by rotating the reflector, the holograms are accurately converged to the positions of human eyes through the relay optical system, continuous scanning is realized through the rotation of the reflector under the condition that the size of an exit pupil is ensured to be fixed, the visible angle range and the image resolution of an image to be watched are increased, and high-resolution holographic near-eye display with a large field angle and a large exit pupil is realized simultaneously by adopting a field angle continuous scanning method. In addition, embodiments 5, 6, and 8 are large-field-angle high-resolution holographic near-eye display devices and display methods that implement field-of-view scanning based on point light source movement, where the holographic near-eye display devices include a point light source movement platform, a collimating lens, a platform movement control system, a beam splitter, a spatial light modulator, a relay optical system, a general controller, and the like. The light emitted by the point light source is collimated by the lens and then irradiates the beam splitter, the parallel light is reflected by the beam splitter and irradiates the spatial light modulator, the parallel light is modulated and diffracted by the calculation hologram loaded on the spatial light modulator, and the diffracted image light is converged to the exit pupil position through the relay optical system to be watched by human eyes. The moving direction and distance of the point light source and the corresponding hologram loaded on the spatial light modulator are calculated by the controller, the direction of parallel light incident on the spatial light modulator can be changed by moving the point light source, the hologram is accurately converged to the position of human eyes by the relay optical system, continuous scanning is realized by moving the point light source under the condition of ensuring that the size of an exit pupil is fixed, the visual angle range and the image resolution of an image are increased, and high-resolution holographic near-eye display with a large visual angle and a large exit pupil is realized simultaneously by adopting a visual angle continuous scanning method.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; within the idea of the invention, also technical features in the above embodiments or in different embodiments may be combined, steps may be implemented in any order, and there are many other variations of the different aspects of the invention as described above; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. The utility model provides a big field angle high-resolution holographically near-to-eye display device based on field of view scanning concatenation which characterized in that: the virtual reality type holographic near-eye display device comprises a point light source (100), a collimating lens (110), a reflector (120), a reflector rotating system (130), a beam splitter (140), a spatial light modulator (150), a relay optical system (160) and a master controller (170), and the virtual reality type holographic near-eye display device is formed; wherein:
a point light source (100) for providing illumination light;
a point light source (100) is arranged on the front focal plane of the collimating lens (110) and is used for generating wide beam parallel light;
the reflector (120) reflects the parallel light and is connected with a reflector rotating system (130);
the reflector rotation control system (130) is used for controlling the reflector (120) to rotate in two dimensions, and the reflector rotation system (130) is connected with the master controller (170);
the beam splitter (140) reflects the parallel light collimated by the collimating lens (110) to irradiate an effective working area of the spatial light modulator;
the spatial light modulator (150) performs diffraction modulation on the parallel light with different angles irradiated thereon and is connected with the master controller (170);
the relay optical system (160) images the spatial light modulator to the vicinity of the pupil of the human eye, and ensures that the spatial light modulator and the pupil surface of the human eye basically form a conjugate relation;
the overall controller (170) is used for calculating the direction and angle of rotation of the mirror (120) and the corresponding hologram sequence required to be loaded on the spatial light modulator (150), and synchronously controlling the hologram sequence.
2. The large field angle high resolution holographic near-to-eye display device based on field-of-view scanning stitching of claim 1, wherein: the optical combiner (180) is positioned behind the relay optical system (160) and is used for enabling external light to directly penetrate into human eyes to form the augmented reality type holographic near-eye display device;
the point light source (100) is the output end of an optical fiber coupling laser, or an LED point light source with narrow bandwidth, or the LED point light source and a narrow band filter;
the collimating lens (110) is a collimating lens group consisting of a single lens, a double-cemented lens or a plurality of lenses; coherent light is emitted by a point light source (100), and after being filtered by a spatial filter, the coherent light is expanded and collimated by a collimating lens (110) to form parallel light of a wide light beam;
the reflecting mirror (120) is a reflecting mirror capable of rotating in two dimensions, or a scanning galvanometer, or a voice coil reflecting mirror; the reflector (120) is connected with a corresponding reflector rotation control system (130) and is used for changing the direction of parallel light irradiated on the spatial light modulator (150);
the beam splitter (140) is a flat beam splitter or a block beam splitter prism, and a polarizing plate can be arranged in front of the beam splitter (140) and used for adjusting the polarization state of a light beam to be matched with the spatial light modulator (150);
the spatial light modulator (150) is a reflective spatial light modulator or a transmissive spatial light modulator;
the spatial light modulator (150) is a phase type spatial light modulator, an amplitude type spatial light modulator, or an amplitude and phase mixed type spatial light modulator.
3. The large-field-angle high-resolution holographic near-eye display device based on field-of-view scanning stitching of claim 1, wherein the relay optical system (160) is a 4f optical relay system consisting of a first relay lens (161) and a second relay lens (162) and images the spatial light modulator (150) near the pupil of a human eye.
4. The large-field-angle high-resolution holographic near-eye display device based on field-scanning stitching of claim 3, wherein the optical axes of the first relay lens (161) and the second relay lens (162) in the relay optical system (160) are coincident, and the back focus of the first relay lens (161) is coincident with the front focus of the second relay lens (162); the first relay lens (161) is a single lens, a double cemented lens or a lens group composed of a plurality of lenses; the second relay lens (162) is a single lens, a double cemented lens, or a lens group composed of a plurality of lenses.
5. The large-field-angle high-resolution holographic near-eye display device based on field-scanning stitching of claim 2, wherein the light combiner (180) is a light combining system consisting of a beam splitter and a lens or a beam splitter and a concave mirror.
6. The large-field-angle high-resolution holographic near-to-eye display device based on field-of-view scanning stitching of claim 2, wherein the light combiner (180) is a semi-transparent and semi-reflective curved light combiner or a holographic optical element with similar functions.
7. The large-field-angle high-resolution holographic near-eye display device based on field-scan stitching of claim 1, wherein a second relay optical system (450) is disposed between the second spatial light modulator (470) and the mirror (120), and a rotation center position of the mirror (120) is conjugated with the second spatial light modulator (470) through the second relay optical system (450); the second relay optical system (450) is a 4f relay optical system consisting of two lenses or lens groups, and focal positions of the two lenses or lens groups are overlapped.
8. A large-field-angle high-resolution holographic near-to-eye display device based on field scanning splicing is characterized in that: the virtual reality type holographic near-to-eye display device comprises a point light source moving platform (500), a collimating lens (510), a platform moving control system (530), a beam splitter (540), a spatial light modulator (550), a relay optical system (560) and a master controller (570), and the virtual reality type holographic near-to-eye display device is formed;
the point light source moving platform (500) is used for providing illumination light, comprises a point light source (501) and a moving platform (502) of a fixed point light source, and controls the point light source (501) to move in space;
a point light source moving platform (500) is arranged on the front focal plane of the collimating lens (510) and is used for generating wide-beam parallel light;
the platform movement control system (530) controls a point light source (501) in the point light source moving platform (500) to translate on the front focal plane of the collimating lens (510), so that wide light beam parallel light with different angles is generated, and the platform movement control system (530) is connected with the master controller (570);
the beam splitter (540) reflects the parallel light collimated by the collimating lens (510) to irradiate an effective working area of the spatial light modulator;
the spatial light modulator (550) performs diffraction modulation on the parallel light with different angles irradiated thereon, and is connected with the master controller (570);
the relay optical system (560) images the spatial light modulator near the pupils of human eyes, and the spatial light modulator and the pupillary plane of the human eyes are ensured to be basically in a conjugate relation;
the total controller (570) is used for calculating the moving range of the point light source moving platform (500) and the corresponding hologram sequence required to be loaded on the spatial light modulator (550), and synchronously controlling the hologram sequence.
9. The large-field-angle high-resolution holographic near-eye display device based on field-of-view scanning stitching of claim 8, further comprising a light combiner (580) located behind the relay optical system (560) and used for allowing external light to directly penetrate into human eyes, so as to realize the augmented reality holographic near-eye display device.
10. A large-field-of-view high-resolution holographic near-eye display method based on field-of-view scanning stitching, which is operated by using the large-field-of-view high-resolution holographic near-eye display device based on field-of-view scanning stitching of claim 1, 2, 8 or 9, and comprises the following operation steps:
the first step is as follows: pupil center position (x) of human eye 0 ,y 0 ) Calculating the rotating angle range (-theta, theta) of the reflecting mirror or the moving range (-L, L) of the point light source and the sequence number of the loaded holograms according to the requirements of the field angle, the resolution ratio and the like of the system;
the second step: the master controller calculates the corresponding rotation angle of the reflector or the spatial position of the point light source movement according to the field angle scanning step length, loads the corresponding hologram, and correspondingly encodes the hologram according to the type of the spatial light modulator to form a loaded and encoded hologram sequence;
the third step: the master controller controls the rotation of the reflector through the reflector rotating system, or controls the movement of the point light source moving platform through the platform moving control system, and controls the spatial light modulator to load a corresponding hologram;
the fourth step: according to the conjugate relation of the optical system, the relay optical system images the spatial light modulator to the position near the pupil of the human eye;
the fifth step: human eyes watch the large-visual-angle high-resolution holographic three-dimensional image spliced by the system through field angle scanning.
CN202210642142.2A 2022-06-07 2022-06-07 Large-field-angle high-resolution holographic near-to-eye display device and display method based on field-of-view scanning splicing Pending CN115145037A (en)

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