Holographic projection lamp, holographic projection system, control method of holographic projection system, equipment, medium and product

Abstract

The invention provides a holographic projection lamp, a holographic projection system, a control method of the holographic projection system, equipment, a medium and a product. A polarization assembly can convert incident light provided by a light source into circularly polarized light in a target rotation direction; the rotation direction of the circularly polarized light based on the target rotation direction carries the phase information of the corresponding target holographic image, so that the holographic images corresponding to different rotation directions are displayed after the circularly polarized light is filtered by the filtering assembly, thereby reducing the structural complexity of the holographic projection system and the holographic projection lamp where the holographic projection system is located, and improving the holographic projection efficiency. Therefore, the realization difficulty and the design and processing cost of the holographic projection lamp are reduced, and application and popularization of the holographic projection lamp are facilitated.

Description

Technical Field

[0001] The present application relates to the field of holographic projection technology, and in particular to a holographic projection lamp, a holographic projection system, and a control method, equipment, medium, and product thereof. Background Art

[0002] A holographic projection lamp is an optical module that can be used to project a specific holographic image. It usually includes a light source, a display object, and a projection system. The light source is used to provide incident light, and the display object can be a shading element such as a film, which can be used to block part of the incident light so that the light passing through the film can be projected at a specified location through the projection system to project a holographic image.

[0003] However, existing holographic projection lamps require different films to display different holographic images, resulting in a complex structure and significantly increasing the difficulty and cost of implementing them. Therefore, reducing the structural complexity of holographic projection lamps is a technical problem that needs to be solved in this field. Summary of the Invention

[0004] The present application provides a holographic projection lamp, a holographic projection system, and a control method, device, medium, and product thereof, so as to reduce the structural complexity of the holographic projection lamp.

[0005] In a first aspect, the present application provides a holographic projection lamp, comprising: a polarization component for converting incident light into circularly polarized light of a target rotation direction; a modulation component, with a light input side arranged toward a light output side of the polarization component, for modulating the rotation direction of the circularly polarized light and attaching phase information of a target holographic image corresponding to the target rotation direction; and a filtering component, with a light input side arranged toward a light output side of the modulation component, for filtering and emitting the circularly polarized light corresponding to the target holographic image to display the target holographic image.

[0006] A second aspect of the present application provides a holographic projection lamp, comprising: a light source for providing incident light; and a holographic projection system as described in the first aspect of the present application, for displaying a holographic image.

[0007] A third aspect of the present application provides a control method for a holographic projection system, which is used to control the holographic projection system as described in the first aspect, including: when the holographic projection system is configured to display a first holographic image, providing the first voltage signal to the first liquid crystal system and providing the second voltage signal to the second liquid crystal system; when the holographic projection system is configured to display a second holographic image, providing the first voltage signal to the second liquid crystal system and providing the second voltage signal to the first liquid crystal system.

[0008] In a fourth aspect, the present application provides a control method for a holographic projection system, which is used to design the orthogonal conversion polarization multiplexing metasurface in the holographic projection lamp as described in the first aspect, comprising: correcting the light intensity information of the holographic image; and iteratively calculating the phase information of the silicon nitride nanostructure when the orthogonal conversion polarization multiplexing metasurface modulates the holographic image based on the intensity information of the incident light and the light intensity information of the holographic image after correction.

[0009] The fifth aspect of the present application provides an electronic device, comprising: a processor, and a memory communicatively connected to the processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method described in the second aspect or the fourth aspect.

[0010] In a sixth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement the method described in the second aspect or the fourth aspect.

[0011] In a seventh aspect, the present application provides a computer program product, including a computer program, which implements the method described in the second aspect or the fourth aspect when executed by a processor.

[0012] In summary, the holographic projection lamp, holographic projection system, and control method, device, medium, and product provided by the present application include a polarization component capable of converting incident light provided by a light source into circularly polarized light of a target rotational direction. The modulation component can, when modulating the circularly polarized light, carry the phase information of the corresponding target holographic image based on the rotational direction of the circularly polarized light of the target rotational direction, so that the filter component filters the circularly polarized light and displays holographic images corresponding to different rotational directions. Therefore, when the holographic projection system needs to display different holographic images, the polarization component converts the incident light into circularly polarized light of different rotational directions, so that the modulation component modulates the rotational direction of the circularly polarized light and carries the phase information of different holographic images. Finally, the filter component filters and emits the circularly polarized light to display different holographic images. As a result, the method and logic for changing the displayed image when the holographic projection lamp needs to display different holographic images are simpler, and the structural complexity of the holographic projection system and the holographic projection lamp in which it is located is reduced, thereby reducing the implementation difficulty and design and processing costs of the holographic projection lamp, which is more conducive to the application and promotion of the holographic projection lamp. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0014] Figure 1 A schematic diagram of the application scenario of this application;

[0015] Figure 2 This is a structural diagram of an embodiment of a holographic projection lamp provided by this application;

[0016] Figure 3 This is a schematic structural diagram of an embodiment of a holographic projection system provided by this application;

[0017] Figure 4 This is a schematic structural diagram of another embodiment of the holographic projection system provided by this application;

[0018] Figure 5 Schematic diagram of the structure of the orthogonal conversion polarization multiplexing metasurface provided by this application;

[0019] Figure 6 A phase diagram of an outgoing light from the orthogonal conversion polarization multiplexing metasurface provided in this application;

[0020] Figure 7 A phase diagram of another type of outgoing light from the orthogonal conversion polarization multiplexing metasurface provided in this application;

[0021] Figure 8 This is a schematic diagram of the structure of the control circuit in the holographic projection system provided by this application;

[0022] Figure 9 This is a schematic diagram of the display effect of the first holographic image provided in this application;

[0023] Figure 10 This is a schematic diagram of the display effect of the second holographic image provided in this application;

[0024] Figure 11 The display effect of the holographic projection image provided by this application;

[0025] Figure 12 This is a schematic diagram of the control timing of the holographic projection image provided by this application;

[0026] Figure 13 A schematic diagram of an improved GS algorithm;

[0027] Figure 14 A schematic diagram of a holographic image processed by the GS algorithm provided in this application;

[0028] Figure 15 This is a flow chart of another embodiment of the control method for the holographic projection system provided by the present application;

[0029] Figure 16 This is a schematic diagram of the structure of an electronic device provided in this application. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0031] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the numbers used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0032] Figure 1 This is a schematic diagram of the application scenario of this application, such as Figure 1 As shown, the present application is applied to the field of holographic projection technology, wherein the holographic projection lamp 1 is an optical module that can be used to project a specific holographic image, and can form a holographic image on a target holographic surface 2. The distance between the holographic projection lamp 1 and the target holographic surface 2 can be, for example, 1 meter, and the range of the formed holographic image can be between 1m*1m. The operating wavelength of the holographic projection lamp 1 can be 455nm visible blue light.

[0033] In the prior art, a holographic projection lamp 1 generally includes structures such as an illumination system, a display object, and a projection system. The illumination system may be a laser, a light emitting diode (LED), a pixelated display, etc., for providing incident light, and may include a beam shaping element, such as a collimating element. The display object may be a light-shielding element, such as a film, which may be used to block part of the incident light so that the light passing through the film is projected at a specified position through the projection system to form a holographic image. The function of the projection system is to image the display object at a specified position.

[0034] However, when the holographic projection lamp 1 in the prior art realizes the display of holographic images through film, although it has the advantages of mature technology and low cost, it is not easy to change the display pattern when the holographic projection lamp 1 needs to display different holographic images, and different films need to be set up, resulting in a high structural complexity of the holographic projection lamp 1, which greatly increases the difficulty and cost of implementing the holographic projection lamp 1.

[0035] Based on this, the present application provides a holographic projection system and a holographic projection lamp 1 in which the system resides, to reduce the structural complexity of the holographic projection lamp 1. The technical solution of the present application is described in detail below using specific embodiments. The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0036] Figure 2 This is a schematic diagram of the structure of an embodiment of the holographic projection lamp provided in this application, which can be applied to Figure 1 In the scenario shown, specifically, Figure 2 The holographic projection lamp 1 shown comprises:

[0037] The light source 12 is used to provide incident light. The light source 12 can be a laser, an LED lamp, a pixelated display, etc. The specific implementation of the light source 12 is not limited in this application.

[0038] The holographic projection system 11 is arranged with its light incident side facing the light exit side of the light source 12. The incident light provided by the light source 12 enters the holographic projection system 11 from the light incident side, and the holographic projection system 11 emits outgoing light corresponding to the holographic image from the light exit side to display the holographic image.

[0039] The holographic projection system 11 provided in this embodiment can be used for at least two different holographic images, which are recorded as a first holographic image and a second holographic image.

[0040] Figure 3 This is a schematic diagram of the structure of an embodiment of the holographic projection system provided in this application, which can be applied to Figure 2 In the holographic projection lamp 1 shown, specifically, as Figure 3The holographic projection system 11 shown comprises:

[0041] Polarization component 111 is configured to convert incident light into circularly polarized light of a target handedness. The light-entry side of polarization component 111 is positioned toward the light-exiting side of light source 12. Light from light source 12 enters polarization component 111 from the light-entry side, and polarization component 111 emits circularly polarized light from the light-exiting side. The circularly polarized light of the target handedness emitted by polarization component 111 can be left-handed circularly polarized light or right-handed circularly polarized light.

[0042] The modulation component 112 is used to modulate the rotation direction of the circularly polarized light and to carry the phase information of the holographic image corresponding to the target rotation direction. The light-incident side of the modulation component 112 is arranged toward the light-outctive side of the polarization component 111. The circularly polarized light provided by the polarization component 111 enters the modulation component 112 from the light-incident side. The modulation component 112 can be used to modulate the circularly polarized light and then emit the modulated circularly polarized light from the light-outctive side. It can be understood that when the circularly polarized light includes left-handed circularly polarized light, the modulation component 112 modulates the left-handed circularly polarized light into right-handed circularly polarized light and carries the phase information of the first holographic image corresponding to the left-handed circularly polarized light; when the circularly polarized light includes right-handed circularly polarized light, the modulation component 112 modulates the right-handed circularly polarized light into left-handed circularly polarized light and carries the phase information of the second holographic image corresponding to the right-handed circularly polarized light.

[0043] The filter assembly 113 is configured to filter out circularly polarized light other than the circularly polarized light corresponding to the target holographic image from the circularly polarized light, thereby filtering the circularly polarized light corresponding to the target holographic image. The light-incident side of the filter assembly is positioned toward the light-outcending side of the modulation assembly 112. The circularly polarized light provided by the modulation assembly 112 enters the filter assembly 113 from the light-incident side. The filter assembly 113 can be configured to filter the circularly polarized light and then emit the filtered circularly polarized light corresponding to the target holographic image from the light-outcending side to display the holographic image.

[0044] In summary, in the holographic projection system 11 provided in this embodiment, the polarization component 111 can convert the incident light provided by the light source into circularly polarized light of the target rotation direction. The modulation component 112 can carry the phase information of the corresponding target holographic image based on the rotation direction of the circularly polarized light of the target rotation direction when modulating the circularly polarized light, so that the filtering component 113 can display holographic images corresponding to different rotation directions after filtering the circularly polarized light.

[0045] It can be seen that when the holographic projection system 11 needs to display different holographic images, the polarization component 111 converts the incident light into circularly polarized light of different rotation directions, so that the modulation component 112 can modulate the rotation direction of the circularly polarized light and carry phase information of different holographic images. Finally, the filter component 113 filters and emits the circularly polarized light to display different holographic images.

[0046] Therefore, when the holographic projection lamp 1 needs to display different holographic images, the method and logic for changing the display image are simpler, and the structural complexity of the holographic projection system 11 and the holographic projection lamp 1 in which it is located is reduced, thereby reducing the implementation difficulty and design and processing costs of the holographic projection lamp 1, which is more conducive to the application and promotion of the holographic projection lamp 1.

[0047] In addition, the holographic projection lamp provided in the present application is only provided with one light source 12, thereby realizing the projection display of multiple holographic projection images with a single light source and without mechanical driving components, and the structure also has the characteristics of being resistant to extreme environments such as high temperature, having a long service life and low manufacturing cost.

[0048] More specifically, Figure 4 This is a structural diagram of another embodiment of the holographic projection system provided by this application, as shown in FIG. Figure 4 The holographic projection system 11 shows Figure 3 A specific implementation of the holographic projection system 11 provided in FIG. Figure 4 As shown, the polarization component 111 in the holographic projection system 11 includes a first polarization module 1111 and a first rotational direction adjustment module 1112, and the filtering component 113 includes a second rotational direction adjustment module 1131 and a second polarization module 1132. In the holographic projection system 11, the first polarization module 1111, the first rotational direction adjustment module 1112, the modulation component 112, the second rotational direction adjustment module 1131 and the second polarization module 1132 are arranged in sequence.

[0049] Specifically, the first polarization module 1111 is disposed with its light incident side facing the light source 12, and is configured to convert incident light into circularly polarized light of a target rotational direction. In one embodiment, the first polarization module 1111 is a polarizing film configured to modulate incident light into left-handed circularly polarized light.

[0050] The light-incoming side of the first polarization module 1111 is disposed toward the light-outgoing side of the first polarization module 1111, and can be used to adjust the incoming circularly polarized light's incoming handedness to the target handedness in a first state, and to maintain the incoming circularly polarized light's handedness at the target handedness in a second state. For example, when the incoming circularly polarized light is left-handed circularly polarized light, the first polarization module 1112 modulates the left-handed circularly polarized light into right-handed circularly polarized light in the first state, and then emits the light from the light-outgoing side. In this case, the circularly polarized light of the target handedness is right-handed circularly polarized light. In the second state, the first polarization module 1112 does not modulate the handedness of the left-handed circularly polarized light but directly emits the light from the light-outgoing side. In this case, the circularly polarized light of the target handedness is left-handed circularly polarized light.

[0051] The modulation component 112 can specifically be an orthogonal conversion polarization multiplexing metasurface. A metasurface is an artificial micro-nanostructure composed of a subwavelength two-dimensional diffraction grating, capable of polarization multiplexing phase control. This means that the same metasurface can have different phase responses for incident light of different polarization states. When applied to holography, it can present different patterns for incident light of different polarization states. In terms of control principles, an orthogonal conversion polarization multiplexing metasurface designed using a scheme that jointly controls geometric phase and propagation phase can achieve the desired phase addition to a polarization state orthogonal to the polarization state of the incident light. This design can be applied by setting a filter component to specify the output polarization state to improve the signal-to-noise ratio and eliminate crosstalk between different polarization channels.

[0052] For example, Figure 5 This is a schematic diagram of the structure of the orthogonal conversion polarization multiplexing metasurface provided in this application, as shown in FIG. Figure 5 The orthogonal conversion polarization multiplexing metasurface shown includes a fused silica substrate 1121 and a silicon nitride nanostructure 1122 disposed on the fused silica substrate 1121. The silicon nitride nanostructure 1122 is used to modulate the handedness of circularly polarized light and carries the phase information of the target holographic image corresponding to the incident target handedness.

[0053] Figure 6 A phase diagram of an outgoing light from the orthogonal conversion polarization multiplexing metasurface provided in this application, wherein the outgoing light carries phase information corresponding to the first holographic image. Figure 7 This is a phase diagram of another outgoing light of the orthogonal conversion polarization multiplexing metasurface provided by this application, wherein the outgoing light carries the phase information corresponding to the second holographic image. Figure 5-Figure 7 It can be seen that the present application uses an orthogonal conversion polarization multiplexing metasurface to emit different holographic images with accompanying phase information according to the different rotation directions of the incident light, thereby realizing the switching and display of multiple holographic images without changing the structure of the holographic projection system 11 and the holographic projection lamp 1 in which it is located.

[0054] The light-entry side of the second handedness adjustment module 1131 is disposed toward the light-exiting side of the modulation assembly 112, and can be used to adjust the handedness of the incident circularly polarized light in the first state, and maintain the handedness of the incident circularly polarized light in the second state. For example, when the incident circularly polarized light of the second handedness adjustment module 1131 is right-handed circularly polarized light, the second handedness adjustment module 1131 modulates the right-handed circularly polarized light into left-handed circularly polarized light in the first state, and then emits the light from the light-exiting side. In the second state, the second handedness adjustment module 1131 does not modulate the handedness of the right-handed circularly polarized light, but directly emits the light from the light-exiting side.

[0055] The second polarization module 1132 is positioned with its light-entering side facing the light-emitting side of the second rotational direction adjustment module 1131, and is configured to filter and emit the circularly polarized light corresponding to the target holographic image. In one embodiment, the second polarization module 1132 is a circularly polarizing analyzer film, which can be used to filter right-handed circularly polarized light while allowing left-handed circularly polarized light corresponding to the target holographic image to pass through.

[0056] In one embodiment, the first rotation direction adjustment module 1112 includes a first liquid crystal device. When a first electrical signal is applied to a motor of the first liquid crystal device, the first liquid crystal device is in a first state, and when a second electrical signal is applied to the motor of the first liquid crystal device, the first liquid crystal device is in a second state.

[0057] In one embodiment, the second rotation direction adjustment module 1112 includes a second liquid crystal device. When a first electrical signal is applied to a motor of the second liquid crystal device, the second liquid crystal device is in a first state, and when a second electrical signal is applied to the motor of the second liquid crystal device, the second liquid crystal device is in a second state.

[0058] Liquid crystal, a special substance between liquid and crystal, possesses fluidity and anisotropic optical properties, making it widely used in display technology and optical modulation. It exhibits an electrically controlled birefringence effect. When exposed to electric fields of varying intensities, the neatly aligned liquid crystal molecules deflect at a certain angle, resulting in different refractive indices for two orthogonally polarized light. This allows it to function as a wave plate. By adjusting the liquid crystal's supply voltage, the properties of the wave plate can be altered, for example, switching between a full-wave plate and a half-wave plate. This allows for dynamic switching between polarization and analysis of the liquid crystal module through paired liquid crystals, improving the holographic performance of orthogonal conversion polarization multiplexing metasurfaces and reducing crosstalk and zero-order crosstalk between polarization channels.

[0059] In one embodiment, the holographic projection system 11 provided by the present application further includes: a first voltage source U1, a second voltage source U2 and a switch module. For example, Figure 8 This is a schematic diagram of the structure of the control circuit in the holographic projection system provided by this application, such as Figure 8 The control circuit can be used to control the first liquid crystal device and the second liquid crystal device to be in corresponding states.

[0060] Specifically, if Figure 8 The first voltage source U1 is used to provide a first voltage signal u1, and the second voltage source U2 is used to provide a second voltage signal u2. The switch module is connected to the first liquid crystal device, the second liquid crystal device, the first voltage source U1 and the second voltage source U2 respectively.

[0061] In one embodiment, if Figure 8The switch module shown is specifically a double-pole double-throw switch, wherein the double-pole double-throw switch includes a first switch K1 and a second switch K2 that are controlled in a linked manner. The fixed end a of the first switch K1 is connected to the first liquid crystal device, and the fixed end b of the second switch K2 is connected to the second liquid crystal device. The first end x of the double-pole double-throw switch is connected to the second voltage source U2, the second end y is connected to the first voltage source U1, and the third end z is connected to the second voltage source U2. When the movable end c of the first switch K1 is connected to the first end x, the movable end d of the second switch K2 is connected to the second end y; when the movable end c of the first switch K1 is connected to the second end y, the movable end d of the second switch K2 is connected to the third end z.

[0062] In one embodiment, the first voltage source is configured to provide a first voltage signal having a voltage value of 5V, a frequency of 1kHz, and a duty cycle of 50%. The second voltage source is configured to provide a second voltage signal having a voltage value of 10V, a frequency of 1kHz, and a duty cycle of 50%.

[0063] It can be seen that through Figure 8 In the control circuit configuration shown, a double-pole double-throw switch controls the switching of the power supply voltages of the two liquid crystal devices. The voltages provided by the two voltage sources always maintain a stable value throughout the entire operation process. Compared with the method of repeatedly changing the output amplitude of the same voltage source, this switching method will have better voltage stability and synchronization, allowing the liquid crystal to function as a half-wave plate or full-wave plate with more stable performance.

[0064] This application also provides a method based on Figure 8 The control method of the holographic projection system 11 shown in the figure can be executed by a control device such as a controller of the holographic projection system 11. Specifically, when the holographic projection system 11 of the holographic projection lamp 1 is configured to display a target holographic image as a first holographic image, the control method ... Figure 8 The control circuit shown can be used to provide a first voltage signal to the first liquid crystal device to control the first liquid crystal device in a first state to function as a half-wave plate, and to provide a second voltage signal to the second liquid crystal device to control the second liquid crystal device in a second state to function as a full-wave plate. The first polarization module 111 is used to modulate incident light into left-handed circularly polarized light. The first liquid crystal device is used to modulate the left-handed circularly polarized light into right-handed circularly polarized light, which is then incident on the orthogonal conversion polarization multiplexing metasurface as circularly polarized light of the target rotational direction. The orthogonal conversion polarization multiplexing metasurface modulates the right-handed circularly polarized light into left-handed circularly polarized light, and carries the phase information of the first holographic image corresponding to the right-handed circularly polarized light. The second liquid crystal device is used to maintain the left-handed circularly polarized light, and the second polarization module 1132 is used to filter the right-handed circularly polarized light, allowing the left-handed circularly polarized light to pass through.

[0065] For example, Figure 9 This is a schematic diagram of the display effect of the first holographic image provided in this application, wherein: Figure 9The left side is the target effect of the first holographic image, and the right side is the display effect of the first holographic image by the holographic projection system 11 provided in this application. It can be seen that compared with the target pattern, the first holographic image surrounded by the red dotted outline has a highly consistent shape within the display range without distortion, no dark corners at the edges, and no zero-order bright spots in the center, and has a clearer display effect.

[0066] When the holographic projection system 11 of the holographic projection lamp 1 is configured to display the target holographic image as the second holographic image, Figure 8 The control circuit shown can be used to provide a second voltage signal to the first liquid crystal device to control the first liquid crystal device to be in the second state to function as a full-wave plate, and to provide a first voltage signal to the second liquid crystal device to control the second liquid crystal device to be in the first state to function as a half-wave plate. The first polarization module 111 is used to modulate the incident light into left-handed circularly polarized light. The first liquid crystal device is used to maintain the left-handed circularly polarized light and use it as circularly polarized light of the target rotation direction to enter the orthogonal conversion polarization multiplexing metasurface, so that the orthogonal conversion polarization multiplexing metasurface modulates the left-handed circularly polarized light into right-handed circularly polarized light and attaches phase information of a second holographic image corresponding to the left-handed circularly polarized light. The second liquid crystal device is used to modulate the right-handed circularly polarized light into left-handed circularly polarized light. The second polarization module 1132 is used to filter the right-handed circularly polarized light and allow the left-handed circularly polarized light to pass through.

[0067] For example, Figure 10 This is a schematic diagram of the display effect of the second holographic image provided in this application, wherein: Figure 10 The left side is the target effect of the second holographic image, and the right side is the display effect of the second holographic image of the holographic projection system 11 provided in this application. It can be seen that compared with the target pattern, the second holographic image surrounded by the red dotted outline has a highly consistent shape within the display range without distortion, no dark corners at the edges, and no zero-order bright spots in the center, and has a clearer display effect.

[0068] In one embodiment, the present application further provides a method for controlling the aforementioned holographic projection system, specifically comprising: cyclically controlling the holographic projection system 11 to stop projecting a holographic image, project a first holographic image, and then project a second holographic image. The order of the first holographic image and the second holographic image can be set based on the holographic image to be projected, without limitation. For example, the holographic projection system 11 can also be cyclically controlled to stop projecting a holographic image, project the second holographic image, and then project the first holographic image.

[0069] For example, Figure 11 From the display effect of the holographic projection image provided in this application, it can be seen that the holographic projection system 11 can stop projecting the holographic image in the time period corresponding to T1, project the second holographic image in the time period corresponding to T2, and project the first holographic image in the time period corresponding to T3.

[0070] Specifically, the control device of the holographic projection system 11 can cyclically control the holographic projection system to sequentially stop projecting the holographic image, project the first holographic image, and project the second holographic image in each of a plurality of consecutive time periods. Alternatively, the control device of the holographic projection system 11 can cyclically control the holographic projection system to sequentially stop projecting the holographic image, project the second holographic image, and project the first holographic image in each of a plurality of consecutive time periods.

[0071] For example, Figure 12 This is a control timing diagram of the holographic projection image provided in this application, wherein the period between time t1 and time t4 is a time period. At time t1 within a time period, the control device controls the light source 12 to stop supplying power, and the light source 12 does not provide incident light, and the holographic projection system 11 stops projecting the image at this time.

[0072] At time t2, the control device controls the power supply Vcc to supply power to the light source 12, so that the light source 12 provides incident light to the holographic projection system 11, and controls the movable end c of the first switch K1 in the double-pole double-throw switch to be connected to the first end x, and the movable end d of the second switch K2 to be connected to the second end y. At this time, the second voltage source U2 provides a second voltage signal to the first liquid crystal device to control the first liquid crystal device to be in the second state to function as a full-wave plate, and the first voltage source U1 provides a first voltage signal to the second liquid crystal device to control the second liquid crystal device to be in the first state to function as a half-wave plate, so that the holographic projection system 11 projects the second holographic image within the time period corresponding to T2.

[0073] At time t3, the control device controls the power supply Vcc to supply power to the light source 12, so that the light source 12 provides incident light to the holographic projection system 11, and controls the movable end c of the first switch K1 in the double-pole double-throw switch to be connected to the second end y, and the movable end d of the second switch K2 to be connected to the third end z. At this time, the first voltage source U1 provides a first voltage signal to the first liquid crystal device to control the first liquid crystal device to be in a first state to function as a half-wave plate, and the second voltage source U2 provides a second voltage signal to the second liquid crystal device to control the second liquid crystal device to be in a second state to function as a full-wave plate, so that the holographic projection system 11 projects the first holographic image within the time period corresponding to T2.

[0074] At time t4, which is the end of one time period and the start of the next time period, the control device starts to control the light source 12 to stop supplying power at time t4. The light source 12 does not provide incident light, and the holographic projection system 11 stops projecting images at this time.

[0075] It can be seen that after Figure 12 The timing method shown in FIG. 1 is used to control the holographic projection lamp 1 so that the holographic projection lamp 1 projects and displays the following cyclically: Figure 11 The image shown realizes the display effect of a circular animation, which can be specifically used to indicate "changing lanes to the right" during driving, greatly enriching the application scenarios and display effects of the holographic projection lamp 1, and further improving the user experience of the holographic projection lamp 1.

[0076] In addition, the present application also provides a method for designing an orthogonal conversion polarization multiplexing metasurface in the holographic projection system 11 of the holographic projection lamp 1 provided in the aforementioned embodiment. The method can be executed by a control device or other electronic device with relevant processing capabilities. The method specifically includes:

[0077] S101: Correcting the light intensity information of the holographic image.

[0078] S102: Iteratively calculating the phase information of the silicon nitride nanostructure when the orthogonal conversion polarization multiplexing metasurface modulates the holographic image based on the intensity information of the incident light and the light intensity information of the corrected holographic image.

[0079] Figure 13 is a schematic diagram of an improved GS algorithm, showing a method for determining the phase information of the silicon nitride nanostructure in S102, such as Figure 13 As shown, first, the intensity information of the incident light is substituted into the Fourier transform of the following formula 1 to obtain the phase parameter Φ, and the phase information of the silicon nitride nanostructure is obtained through the inverse Fourier transform corresponding to the following formula 1, and the phase parameter Φ is iterated into the Fourier transform for calculation.

[0080]

[0081] x, y are the far-field position coordinates of the surface where the holographic image is located, x1, y1 are the near-field position coordinates of the surface where the metasurface is located, It is used to describe the light field, F represents Fourier transform, λ is the wavelength, k is the wave vector, and is calculated by the following formula k = 2π / λ. z1 represents the diffraction distance, that is, the distance between the surface where the metasurface is located and the surface where the target holographic image is located. The meanings of the remaining mathematical symbols are the same as those of the classic GS algorithm and will not be repeated here.

[0082] Specifically, the GS algorithm, short for the Gerchberg-Saxton algorithm, is the most basic hologram target phase algorithm. It expresses the far-field Fraunhofer diffraction in scalar diffraction theory in the form of Fourier transform, thereby achieving fast calculation and iteration. However, its use conditions must meet the paraxial approximation conditions, one of which is that the size of the diffraction surface and the target surface should be much smaller than the propagation distance. Therefore, for the case where the target pattern size and the propagation distance are on the same order of magnitude, if the traditional GS algorithm is directly applied to iteratively calculate the hologram phase, and a scalar diffraction algorithm such as the Rayleigh-Sommerfeld integral is used to calculate and simulate its far-field projection pattern, an image with both distortion and dark corners will be obtained.

[0083] For example, Figure 14 This is a schematic diagram of a holographic image processed by the GS algorithm provided in this application, such as Figure 14 As shown in the figure, for the target grid holographic image S1 to be displayed, if the GS algorithm is directly used, the display effect of the obtained holographic image is S2. It can be seen that for the Fresnel zone and non-paraxial approximation where the projection distance is not much greater than the wavelength and the projection pattern size, the use of this algorithm will cause pattern distortion, especially edge distortion and dark corners at the four corners of the holographic image.

[0084] Therefore, in the method provided in this embodiment, before using the improved GS algorithm for calculation, the light intensity information of the holographic image used in the calculation is also corrected and processed. Figure 13 The improved GS algorithm shown uses the light intensity information of the corrected holographic image to perform calculations, thereby obtaining more accurate phase information of the silicon nitride nanostructure.

[0085] In one embodiment, correcting the light intensity information of a holographic image includes: calculating the ratio of the light intensity information at each pixel position to the a-power of the cosine value of the diffraction angle between the pixel position and the light source, to obtain the corrected light intensity information at each pixel position in the holographic image. a is a non-negative real number, which can be called a light intensity calibration factor. It is specifically used to pre-compensate the light intensity of the holographic image according to the characteristics of being dark at the center and bright at the edges and corners. The parameter a in the correction process can be debugged through experiments based on the desired calibration results, for example, it can be set to 4. The above correction process can be expressed by the following formula 2:

[0086]

[0087] Among them, x, y are the coordinate system of the surface position of the holographic image, I0 is the light intensity distribution before calibration, I1 is the light intensity distribution after calibration, and θ(x, y) is the diffraction angle between the pixel position and the light source, that is, the angle between the light emitted by the metasurface and transmitted to the coordinate and the optical axis.

[0088] In such Figure 13 In the example described above, when the light intensity information of the holographic image after the correction is used to perform the GS algorithm calculation, the display effect of the holographic image can be obtained as follows: Figure 14 As can be seen from S3 in the figure, the problems of edge distortion and dark corners caused by the four corners of the holographic image are overcome, making the brightness of the holographic projection pattern more uniform in the entire projection range, with no grid distortion and no dark corners at the edges.

[0089] Figure 15 This flowchart, a flow chart of another embodiment of the control method for the holographic projection system provided herein, illustrates a specific method for designing the orthogonal conversion polarization multiplexing metasurface in a holographic projection lamp. The method includes: first determining the operating wavelength and material system of the holographic projection lamp 1, scanning the nanostructure and geometric parameters for electromagnetic simulation, thereby determining the structural period and height required for the orthogonal conversion polarization multiplexing metasurface and establishing a structural database; then, setting a reasonable holographic pattern within the spectral range defined by the nanostructure period. The above-described metasurface design process is a common understanding in the field and will not be further elaborated.

[0090] Then, the light intensity calibration factor is set as shown in Formula 2, and Figure 13 The target phase is calculated iteratively using the modified GS algorithm shown in FIG. The target phase of the orthogonal conversion polarization multiplexing metasurface is verified by the scalar diffraction algorithm. When it is determined that the light intensity at the edge of the holographic image displayed after the silicon nitride nanostructure modulation is different from the light intensity at the center, the light intensity calibration factor is set again as shown in formula 2, and the light intensity information is corrected. Then, the target phase of the orthogonal conversion polarization multiplexing metasurface is verified by the scalar diffraction algorithm. Figure 13 The improved GS algorithm iteratively calculates the target phase until it is determined that the light intensity at the edge of the holographic image displayed after modulation by the silicon nitride nanostructure is different from that at the center.

[0091] Finally, a silicon nitride nanostructure of an orthogonal conversion polarization multiplexing metasurface is constructed based on the target phase and the previously determined holographic pattern. Electromagnetic simulation is performed based on the constructed orthogonal conversion polarization multiplexing metasurface, and the simulation results are obtained through a scalar diffraction algorithm.

[0092] In one embodiment, an operator may observe the holographic image to determine whether the light intensity at the edge of the holographic image is different from the light intensity at the center.

[0093] Alternatively, in another embodiment, a quantitative threshold for the difference between the light intensity at the edge position and the light intensity at the center position of the holographic image can be set so that when the light intensity between the two is greater than the threshold, it is determined whether there is a difference in the light intensity between the two. The specific setting of the threshold can be an empirical value or calibrated after observation by an operator.

[0094] In the aforementioned embodiments of the present application, the control method of the holographic projection system provided by the embodiments of the present application is introduced. In order to realize the various functions of the methods provided by the above embodiments of the present application, the control device of the holographic projection system as the execution subject can be implemented by hardware structure and / or software module, for example, in the form of hardware structure, software module, or hardware structure plus software module to realize the above functions. Whether a function of the above functions is implemented in the form of hardware structure, software module, or hardware structure plus software module depends on the specific application and design constraints of the technical solution.

[0095] It should be understood that the division of the various modules of the above device is merely a division of logical functions. In actual implementation, they can be fully or partially integrated into one physical entity, or they can be physically separated. Moreover, these modules can all be implemented in the form of software called by a processing element; or they can all be implemented in the form of hardware; or some modules can be implemented in the form of software called by a processing element, and some modules can be implemented in the form of hardware. For example, the processing module can be a separately established processing element, or it can be integrated into a chip of the above device. In addition, it can also be stored in the memory of the above device in the form of program code, and called by a processing element of the above device to perform the functions of the above-mentioned module. The implementation of other modules is similar. In addition, these modules can all or partly be integrated together, or they can be implemented independently. The processing element described here can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each module above can be completed by an integrated logic circuit of hardware in the processor element or instructions in the form of software.

[0096] For example, the above modules can be one or more integrated circuits configured to implement the above methods, such as one or more application specific integrated circuits (ASICs), or one or more microprocessors (digital signal processors, DSPs), or one or more field programmable gate arrays (FPGAs). For another example, when a module is implemented in the form of a processing element scheduling program code, the processing element can be a general-purpose processor, such as a central processing unit (CPU) or other processor that can call program code. For another example, these modules can be integrated together and implemented in the form of a system-on-a-chip (SOC). In the above embodiments, all or part of them can be implemented by software, hardware, firmware or any combination thereof.

[0097] For example, Figure 16 This is a schematic diagram of the structure of an electronic device provided in this application, such as Figure 16 The device shown can be used as a control of a holographic projection system to execute the control method provided by the control of the holographic projection system in any embodiment of the present application.

[0098] In one embodiment, if Figure 16 The electronic device 1000 shown includes one or more processors 1001 and a memory 1002. The memory 1002 is used to store computer executable instructions, and the processor 1001 can execute the computer executable instructions stored in the memory 1002. When the computer executable instructions are executed by the processor 1001, the processor 1001 implements the control method of any of the aforementioned embodiments of the present application. In one embodiment, Figure 16 The electronic device 1000 shown further includes a communication interface 1003 , wherein the processor 1001 can communicate with other devices via the communication interface 1003 .

[0099] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly implemented by a hardware processor or implemented by a combination of hardware and software modules in the processor.

[0100] The memory may include a high-speed memory (Random Access Memory, RAM), and may also include a non-volatile memory (NVM), such as at least one disk memory.

[0101] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be classified into address buses, data buses, and control buses. For ease of illustration, the buses in the drawings of this application are not limited to just one bus or just one type of bus.

[0102] An embodiment of the present application further provides a chip for executing instructions, wherein the chip is used to execute any of the control methods for the holographic projection system described above in the present application.

[0103] An embodiment of the present application further provides a computer program product, including a computer program, which, when executed, implements any of the aforementioned control methods for the holographic projection system of the present application.

[0104] The present application also provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are executed, they can be used to implement a control method for a holographic projection system as described in any of the aforementioned embodiments of the present application.

[0105] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile memory device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0106] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0107] The division of units is merely a logical functional division; actual implementations may employ alternative divisions, such as combining or integrating multiple units or components into another system, or omitting or disabling certain features. Furthermore, any direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between devices or units, either through an interface, electrical, mechanical, or other means.

[0108] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0109] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0110] Those skilled in the art will appreciate that all or part of the steps in the above-described method embodiments can be implemented using hardware associated with program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0111] Finally, it should be noted that those skilled in the art will readily identify other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The present invention is not limited to the precise structure described above and illustrated in the accompanying drawings, and various modifications and variations may be made without departing from the scope thereof. The scope of the present invention is limited solely by the appended claims.

Claims

1. A holographic projection system, characterized in that: include: A polarization component for converting incident light into circularly polarized light of a target rotation direction; a modulation component, the light incident side of which is arranged toward the light exit side of the polarization component, for modulating the handedness of the circularly polarized light and attaching phase information of the target holographic image corresponding to the target handedness; The filter component is arranged with its light incident side facing the light emitting side of the modulation component, and is used for filtering and emitting the circularly polarized light corresponding to the target holographic image to display the target holographic image.

2. The holographic projection system according to claim 1, characterized in that: The polarization component includes: A first polarization module converts incident light into circularly polarized light; The first rotation adjustment module is arranged with the light incident side facing the light exit side of the first polarization module, and is used to adjust the rotation of the circularly polarized light to the target rotation in a first state, and to maintain the rotation of the circularly polarized light to the target rotation in a second state.

3. The holographic projection system according to claim 2, characterized in that: The filter assembly comprises: a second handedness adjustment module, the light incident side of which is arranged toward the light exit side of the modulation component, for adjusting the handedness of the circularly polarized light to the target handedness in a first state, and maintaining the handedness of the circularly polarized light to the target handedness in a second state; The second polarization module is arranged with its light incident side facing the light exiting side of the second rotation direction adjustment module, and is used for filtering and emitting the circularly polarized light corresponding to the target holographic image.

4. The holographic projection system according to claim 2 or 3, characterized in that: The modulation component includes: An orthogonal conversion polarization multiplexing metasurface includes: a fused quartz substrate, and a silicon nitride nanostructure arranged on the fused quartz substrate, wherein the silicon nitride nanostructure is used to modulate the handedness of the circularly polarized light and carries phase information of a target holographic image corresponding to the target handedness.

5. The holographic projection system according to claim 4, characterized in that: The first rotation direction adjustment module includes a first liquid crystal device, which is in the first state when a first voltage signal is applied to the electrodes of the first liquid crystal device and is in the second state when a second voltage signal is applied; The second rotation direction adjustment module includes a second liquid crystal device. When a first voltage signal is applied to electrodes of the second liquid crystal device, the electrodes are in the first state, and when a second voltage signal is applied, the electrodes of the second liquid crystal device are in the second state.

6. The holographic projection system according to claim 5, characterized in that: Also includes: a first voltage source, configured to provide the first voltage signal; a second voltage source, configured to provide the second voltage signal; a switch module, connected to the first liquid crystal device, the second liquid crystal device, the first voltage source, and the second voltage source, respectively, and configured to: When the holographic projection system is configured to display a first holographic image, the first voltage source provides the first voltage signal to the first liquid crystal system, and the second voltage source provides the second voltage signal to the second liquid crystal system; When the holographic projection system is configured to display a second holographic image, the first voltage source provides the first voltage signal to the second liquid crystal system, and the second voltage source provides the second voltage signal to the first liquid crystal system.

7. The holographic projection system according to claim 6, characterized in that: The switch module includes a double-pole double-throw switch.

8. A holographic projection lamp, characterized in that: include: a light source, for providing incident light; The holographic projection system according to any one of claims 1 to 7, used for displaying holographic images.

9. A method for controlling a holographic projection system, characterized in that: Used to control the holographic projection system according to any one of claims 5 to 7, comprising: When the holographic projection system is configured to display a first holographic image, providing the first voltage signal to the first liquid crystal system and providing the second voltage signal to the second liquid crystal system; In case that the holographic projection system is configured to display a second holographic image, the first voltage signal is provided to the second liquid crystal system and the second voltage signal is provided to the first liquid crystal system.

10. The method according to claim 9, characterized in that Also includes: The holographic projection system is cyclically controlled to sequentially stop projecting the holographic image, project the first holographic image, and project the second holographic image.

11. The method according to claim 10, characterized in that The cyclically controlling the holographic projection system to sequentially stop projecting the holographic image, project the first holographic image, and project the second holographic image includes: In each of a plurality of consecutive time periods, the holographic projection system is controlled to sequentially stop projecting the holographic image, project the first holographic image, and project the second holographic image.

12. A method for controlling a holographic projection system, characterized in that: The orthogonal conversion polarization multiplexing metasurface used for designing the holographic projection lamp according to any one of claims 4 to 7 comprises: performing correction processing on light intensity information of the holographic image; The phase information of the silicon nitride nanostructure when the orthogonal conversion polarization multiplexing metasurface modulates the holographic image is iteratively calculated according to the intensity information of the incident light and the light intensity information of the holographic image after correction.

13. The method according to claim 12, characterized in that The correcting the light intensity information of the holographic image includes: The corrected light intensity information of each pixel position in the holographic image is obtained according to the ratio of the light intensity information of each pixel position in the holographic image to the a-th power of the cosine value of the diffraction angle between the pixel position and the light source, where a is a non-negative real number.

14. The method according to claim 12 or 13, characterized in that Also includes: When it is determined that the light intensity at the edge of the holographic image displayed after modulation by the silicon nitride nanostructure is different from that at the center, the light intensity information of the holographic image is re-corrected and the phase information of the silicon nitride nanostructure is determined.

15. An electronic device, characterized in that: include: a processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 9 to 14.

16. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 9 to 14 when executed by a processor.

17. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 9 to 14 when executed by a processor.

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