A holographic projector and a holographic display system

Abstract

The present invention discloses a holographic projector and a holographic display system, including an imaging chip disposed inside the holographic projector for providing an equivalent image plane, a light source for providing light to the imaging chip, and an imaging lens group corresponding to the equivalent image plane and used for optical imaging. The power density ρ of the light source P satisfies: #imgabs0# By using the holographic projector of the present invention, it is proven through a large number of experiments that the imaging quality and user comfort are significantly improved, thereby optimizing the product performance of the holographic projector.

Description

Technical Field

[0001] The present invention relates to the technical field of holographic display, and particularly relates to a holographic projector and a holographic display system. Background Art

[0002] A live / geometric holographic display system is a real stereoscopic display technology that can be realized. This new display system uses a holographic projector as the core display element, and its working mode is very different from that of the previous 2D projection display system. The holographic projector usually includes multiple imaging chips and correspondingly uses multiple light sources, so the light source power of the holographic projector will increase exponentially. However, this type of display also has the characteristic of focused display, which can concentrate light in a small display window, and this characteristic greatly reduces the requirement for light source power. There are two opposite considerations for the light source power, and there are no quantifiable design specifications for both considerations, which increases the design difficulty of the holographic projector, the product performance of the holographic projector cannot be optimized, and the imaging quality of the holographic projector and the comfort of users during use are reduced.

[0003] Therefore, how to optimize the product performance of the holographic projector is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0004] The purpose of the present invention is to provide a holographic projector and a holographic display system to optimize the product performance of the holographic projector.

[0005] To achieve the above purpose, the present invention provides a holographic projector, including an imaging chip disposed inside the holographic projector for providing an equivalent image plane, a light source for providing light to the imaging chip, an imaging lens group corresponding to the equivalent image plane and used for optical imaging, and the power density ρ of the light source P satisfies:

[0006] wherein, the power density of the light source The unit is

[0007] P is the light source power, and the unit is W;

[0008] S0 is the aperture area of the light-transmitting hole of the outermost lens in the imaging lens group, and the unit is m 2 ;

[0009] S 10 is the area of the light spot projected by the holographic projector on a plane perpendicular to the principal optical axis of the outermost lens at a distance of 10 cm from the outermost lens in the imaging lens group, and the unit is m 2 ;

[0010] S 100is the area of the light spot projected by the holographic projector on the plane perpendicular to the principal optical axis of the outermost lens in the imaging lens group at a distance of 100 cm from the outermost lens, with the unit of m 2 .

[0011] Preferably, the power density ρ of the light source P satisfies:

[0012] Preferably, the power density ρ of the light source P satisfies:

[0013] Preferably, the luminous flux density ρ of the light source L satisfies:

[0014] wherein, the luminous flux density of the light source with the unit of

[0015] L is the luminous flux of the holographic projector, with the unit of lm.

[0016] Preferably, the depth of field performance ability of the holographic projector ≥ 5 m.

[0017] Preferably, the image plane density ρ of the holographic projector l satisfies:

[0018] wherein, the image plane density with the unit of

[0019] n is the number of image planes, with the unit of 1;

[0020] l is the depth value of the display space, with the unit of m.

[0021] Preferably, the image plane density ρ of the holographic projector l satisfies:

[0022]

[0023] Preferably, the image plane density ρ of the holographic projector l satisfies:

[0024]

[0025] Preferably, the holographic projector is a self-cooling structure.

[0026] Preferably, it further includes a volume scanning mechanism capable of performing volume scanning.

[0027] The present invention also discloses a holographic display system, including a holographic screen and a projection device, and the projection device is the holographic projector described in any one of the above.

[0028] Preferably, the holographic display system is a geometric holographic display system or an in-situ holographic display system.

[0029] Preferably, the geometric holographic screen is a transmissive geometric holographic screen or a reflective geometric holographic screen.

[0030] Preferably, the light source of the holographic projector uses a coherent light source.

[0031] Preferably, it further includes a base and a support rod, and the support rod connects the holographic projector and the base.

[0032] Preferably, the support rod includes an upper connecting rod and a lower connecting rod. The upper connecting rod is connected to the holographic projector and can realize the left-right swing and up-down pitching of the holographic projector; the lower connecting rod is connected to the base and can realize rotation and / or up-down pitching.

[0033] Preferably, it further includes an eye tracking module.

[0034] Preferably, it further includes an interactive action capture module.

[0035] For the holographic projector of the present invention, the power density ρ of the light source P satisfies: And through a large number of experiments, it is proved that the imaging quality and user comfort are significantly improved, thus optimizing the product performance of the holographic projector. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0037] Figure 1 It is a schematic structural diagram of a holographic projector provided by an embodiment of the present invention;

[0038] Figure 2 It is a three-dimensional principle schematic diagram of a holographic projector provided by an embodiment of the present invention;

[0039] Figure 3 It is a front view principle schematic diagram of a holographic projector provided by an embodiment of the present invention;

[0040] Figure 4Schematic diagram of the structure of a holographic projector provided by an embodiment of the present invention;

[0041] Figure 5 Schematic diagram of the structure of a holographic display system provided by an embodiment of the present invention;

[0042] Figure 6 Schematic diagram of the structure of another holographic display system provided by an embodiment of the present invention;

[0043] Figures 7 to 10 Schematic diagrams of different angles of the structure of yet another holographic display system provided by an embodiment of the present invention.

[0044] Wherein: 100 is a holographic projector; 200 is a holographic screen, 300 is a coherent light source, 400 is a support rod, and 500 is a base. Detailed implementation manners

[0045] The core of the present invention is to provide a holographic projector and a holographic display system to optimize the product performance of the holographic projector.

[0046] As can be seen from the description of the background technology, the light source power in the current holographic projector will increase exponentially; in addition, in the volumetric display (3D display) scenario, each pixel (voxel) in the display space is an independent light-emitting point, which is several orders of magnitude more than the pixel points displayed by traditional 2D projection devices. Therefore, from this logic, the luminous flux of the light source also needs to be increased correspondingly. In addition, due to the particularity of the holographic display system, there are often optical elements with low optical utilization rate in its optical path setting, which greatly reduces the utilization rate of light. Therefore, it is also necessary to increase the brightness of the light source. However, this type of display also has the characteristic of focused display, which can concentrate the light in a small display window (viewport), and this characteristic greatly reduces the brightness requirement for the light source.

[0047] In terms of application scenarios, holographic projectors are often used in holographic display systems. Holographic projectors are often non-fixed in such display systems and need to move with the user, which is very different from the previous fixed projection devices. This requires the holographic projector to be flexible and lightweight, and the design should be as simple as possible to avoid structural redundancy (such as reducing the heat generation problem as much as possible, thereby simplifying the heat dissipation design or omitting the heat dissipation design).

[0048] In summary, due to the uniqueness and complexity of the holographic display system, there are two opposite perspectives for optoelectronic parameters, and there are no quantifiable design specifications for each perspective. Therefore, the design difficulty is extremely high. In practice, it has also been found that professional designers familiar with the traditional projection design field and other optical designers are unable to complete the design of an ideal holographic projector. Many of the designed products can only achieve the function of 3D display, but their performance and display effects are very poor and cannot meet the normal needs of users.

[0049] Considering that the personnel in this field cannot optimize the product performance of the holographic projector based on the design experience of previous display systems, the present invention provides an idea for optimizing the holographic projector, enabling practitioners without any design experience to develop products with superior performance according to the technical information of the present invention.

[0050] In order to enable the technical personnel in this field to better understand the technical solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0051] As Figure 1 and Figure 2 shown, a holographic projector disclosed by the present invention includes an imaging chip disposed inside the holographic projector for providing an equivalent image plane, a light source for providing light to the imaging chip, an imaging lens group corresponding to the equivalent image plane and used for optical imaging, and the power density ρ of the light source P satisfies:

[0052] Among them, the power density of the light source is in the unit of

[0053] P is the power of the light source, in the unit of W;

[0054] S0 is the aperture area of the light-transmitting hole 101 of the outermost lens in the imaging lens group, in the unit of m 2 ;

[0055] S 10 is the area of the light spot 102 projected by the holographic projector on the plane α perpendicular to the main optical axis O1 of the outermost lens at a distance of 10 cm from the outermost lens in the imaging lens group, in the unit of m 2 ;

[0056] S 100 is the area of the light spot 103 projected by the holographic projector on the plane β perpendicular to the main optical axis O1 of the outermost lens at a distance of 100 cm from the outermost lens in the imaging lens group, in the unit of m 2 .

[0057] For the holographic projector of the present invention, the power density ρ of the light source P satisfies: A large number of experiments have proved that the imaging quality and user comfort have been significantly improved, thereby optimizing the product performance of the holographic projector.

[0058] Preferably, the power density of the light source is P satisfy:

[0059] Preferably, the power density of the light source is P satisfy:

[0060] It should be noted that the imaging chip in the present invention adopts LCD, LCOS, OLED, DMD and the like; the light source adopts a bulb, LED, laser light source or other light-emitting device, and its power can be calculated by measuring the voltage and current in the working state. In some special cases, the light source and the imaging chip are integrated together, and the power of the light source needs to be calculated according to the power of the entire integrated device (because the power consumption of the light-emitting function during its working process is relatively high). For example, if the display is realized by OLED, the power of the light source can be calculated according to the power of OLED; the imaging lens group can adopt a conventional lens combination lens group (similar to a camera, a holographic projector lens group) or a lens group containing a flexible or liquid zoom lens or a new type of super lens. The working process is that the imaging chip receives the image content to be displayed and displays a pattern; the displayed pattern is projected through the imaging lens group.

[0061] In order to pursue high brightness and contrast, traditional projection display systems often design the power and luminous flux as large as possible, and the corresponding light source power will increase. However, in the design of holographic display systems, this design experience is completely invalid. First of all, the power of the light source cannot be too large, otherwise it will not only cause excessive energy consumption, but also seriously affect the life and reliability of the device due to heat. From another perspective, in order to solve the problem of serious heat generation, additional heat dissipation components or heat dissipation space can be set, which will make the holographic projector very bulky and not conducive to the holographic projector tracking movements and other actions (holographic projectors often need to work in dynamic motion scenes, such as holographic display systems). Secondly, a large light source power also means a large luminous flux, and the luminous flux is not the larger the better. If the display volume does not match the luminous flux, the light is too strong, and the light is too strong, which will cause eye discomfort or even damage.

[0062] The inventor has discovered through research that there is a certain correlation between the light source power and the luminous flux. When the light source power is designed within a reasonable range, the luminous flux is also limited within a relatively reasonable range. At this time, the configuration of the optoelectronic parameters reaches a relatively optimized state. However, due to the certain uncertainty between the light source power and the luminous flux, such as changes in the light source type, the concentration of the light path, and changes in the diaphragm design, etc., will all cause certain fluctuations in the relationship between the light source power and the luminous flux. In this case, often when the design of the light source power density is already relatively appropriate, there is still room for further optimization of the luminous flux density (changing the light source, adjusting the concentration ratio, adjusting the filter ratio, etc.). Therefore, the holographic projector can also adjust the luminous flux density to make the product perform more excellently. Preferably, the light source power P of the holographic projector should not exceed 30W. Under this condition, the heat generation of the light source will be greatly reduced, thereby simplifying the heat dissipation design, making the whole machine flexible and portable, and can also extend the life of the device, improve the reliability, and at the same time, the luminous flux density is also within a relatively reasonable range. If a light source power lower than 12W is used in the design, a self-cooling structure can be adopted, without the need to use air-cooled or water-cooled components, and even multi-fin heat dissipation structural parts are not required. At the same time, the luminous flux density parameters are also better constrained, and even for the case of an ultra-large display volume, the luminous flux does not need to exceed 200lm. In one example of the present invention, the luminous flux density ρ of the light source L satisfies:

[0063] wherein, the luminous flux density of the light source The unit is

[0064] L is the luminous flux of the holographic projector, and the unit is lm.

[0065] The present application also discloses a method for measuring the luminous flux L. This measurement method can refer to the test method of ANSI lumens, including:

[0066] 1) Set the distance between the holographic projector in the display system and the test screen to: 2.4 meters;

[0067] 2) The test screen is 60 inches;

[0068] 3) Use an illuminance meter to measure the illuminance at each point of the nine intersection points of the "field" shape on the test screen, and obtain the average illuminance of the 9 points;

[0069] 4) The average illuminance multiplied by the projected image area is ANSI lumens, that is, the display luminous flux of the present invention.

[0070] For different displayed images, the measured value of L may vary greatly. In actual tests, it is preferably to display a full-white image for testing, that is, the case where each pixel is displayed as white;

[0071] When the illumination area of the holographic projector cannot be well matched with the test screen, the illuminance test is carried out by taking points according to the actual illumination area. Preferably, 8 points are evenly selected in the light band about 10 cm to 30 cm away from the outer boundary of the illumination area within the illumination area and 1 point within the illumination area not exceeding 20 cm from the center of the holographic screen. A total of 9 points are used for the illuminance test, and then the average value of the 9 illuminance values is multiplied by the actual area of the illumination area to obtain the display luminous flux value.

[0072] For the convenience of testing, the test can be carried out in a dark room.

[0073] In addition to the above-mentioned optoelectronic parameters having a relatively large impact on the performance of the holographic projector, the depth of field performance ability is another relatively important characterization index. Generally, if the depth of field performance ability can reach 5 m, that is, when the distance between the nearest image plane and the farthest image plane that the holographic projector can project reaches 5 m, a very shocking 3D effect can be shown. Therefore, the depth of field performance ability of the holographic projector ≥ 5 m. Specifically, it can be achieved through the optical path configuration, which will not be elaborated as it is prior art. It should be added that when the all-solid-state scheme is adopted, the holographic projector includes multiple projection chips. At this time, it is only necessary to ensure that the distance between the two farthest image planes projected is greater than 5 m. A special note is that for a holographic projector using the time-division multiplexing method (such as the volume scanning method, etc.), the nearest image plane and the farthest image plane cannot be displayed simultaneously at the same time. Therefore, during design, the nearest image plane and the farthest image plane need to be tested, verified, and optimized separately.

[0074] For a holographic projector, the more image planes it can provide, in principle, the better the 3D display effect will be. However, in actual situations, the more image planes there are, the correspondingly greater the design difficulty will be, and at the same time, the cost will also increase significantly. With a relatively limited number of image planes, a very realistic 3D effect can also be achieved through reasonable image plane allocation. In real life, the visual information received by the human eye can be divided into a near-field scene, a mid-field scene, and a far-field scene according to the distance. Therefore, in the present invention, the number of display image planes is adjusted according to these three scenes to achieve a 3D scene reconstruction very close to the real world. For better expression, the concept of image plane density is introduced here. The image plane density is the ratio of the number of image planes within a certain display range to the depth value of the display space, that is: image plane density unit where n is the number of image planes, with the unit of 1; l is the depth value of the display space, with the unit of m. For example, when the depth value of the display space within a certain display range is 20 m and the number of image planes is 9, then at this time, the image plane density is

[0075] It should be noted that according to the prior art, the depth value l of the display space in the near-field scenario satisfies: 0 ≤ l ≤ 1 m, the depth value l of the display space in the mid-field scenario satisfies: 0 ≤ l ≤ 2.12 m, and the depth value l of the display space in the far-field scenario satisfies: 0 ≤ l ≤ 5 m.

[0076] As a preferred design, in the near-field scenario (within 0 - 1 meter), there should be at least one image plane to ensure the authenticity of the near-field image. The near-field image plane density

[0077] In the mid-field scenario (within 0 - 2.12 meters), there is a relatively obvious spatial span. At this time, at least two image planes are required to represent the front-back relationship. The mid-field image plane density

[0078] In the far-field scenario (within 0 - 5 meters), the spatial span is large. At this time, in addition to representing the front-back relationship, it is also necessary to be able to represent the distant background. Therefore, an additional image plane is required. Thus, the far-field image plane density

[0079] Furthermore, in order to better simulate the visual effects of the real world, it is also necessary to be able to represent a realistic near-eye scenario to show the process of the scenery approaching the eyes. At this time, an image plane that can represent the near-eye scenario (within 0 - 0.3 meters) is required. Preferably, in the near-field scenario (within 0 - 1 meter), there should be at least one image plane to ensure the authenticity of the near-field image. The near-field image plane density

[0080] In the mid-field scenario (within 0 - 2.12 meters), there is a relatively obvious spatial span. At this time, at least two image planes are required to represent the front-back relationship. The mid-field image plane density

[0081] In the far-field scenario (within 0 - 5 meters), the spatial span is large. At this time, in addition to representing the front-back relationship, it is also necessary to be able to represent the distant background. Therefore, an additional image plane is required. Thus, the far-field image plane density

[0082] In order to achieve multi-focal plane display or volumetric scanning 3D display, an image plane integrating mirror group can also be set inside the holographic projector, or a volumetric scanning mechanism can be added for volumetric scanning imaging. These all have mature solutions and will not be elaborated here.

[0083] Table 1 shows several embodiments of the present invention to illustrate that the present invention optimizes the product performance by adjusting parameters such as light source power, number of pilot points, and light flux density.

[0084] Table 1 is a comfort score table for the examples and comparative examples

[0085]

[0086] It can also be found in the above embodiments that there are certain functional relationships between the user comfort score and the light source power density and the luminous flux density respectively. Although there are certain fluctuations in the test data of the embodiments, during actual design, function fitting can be performed based on the data of the above embodiments (such as fitting with a polynomial, such as quadratic function fitting, or piecewise linear fitting), and then the ranges of the light source power density and the luminous flux density corresponding to a comfort level greater than a certain score (such as 70 points, 80 points, 90 points, etc.) can be found as a further optimized selection scheme. Moreover, in some special cases, such as simple teaching demonstrations, advertisements, etc., the requirements for imaging quality and user comfort are relatively low, but the requirements for costs and other aspects are relatively high. At this time, according to the fitting function and combined with costs, an interval with a relatively low comfort score that meets the usage requirements (such as 40 - 60 points) can be found. Although the design of this interval may not be given in the embodiments, the corresponding design can be extrapolated based on the fitting function relationship as a reference for optimizing the product.

[0087] When actually debugging and verifying the optoelectronic parameters, switching the light source or changing the optical path design is a very cumbersome task. A relatively effective method is that during debugging and verification, a fixed light source can be used, and the luminous flux can be controlled by changing the aperture size to change the light source occlusion situation or by adding / changing filters, beam splitting ratios, light concentration ratios, etc., thereby greatly simplifying the workload of luminous flux adjustment and quickly verifying the design parameters. After the luminous flux density parameters are verified, a suitable light source can be selected according to the parameters.

[0088] On the other hand, limited by the capabilities of the driving devices (such as electric motors, servo motors, etc.), the total mass M of the holographic projector cannot be too large, otherwise the inertial effect will greatly increase the tracking difficulty, and at the same time, it is easy to cause the driving device to operate overloaded and be damaged or the life reliability to decrease. Therefore, it is preferably M ≤ 2.12 kg, and at this time, very good tracking effects can be achieved for learning and office scenarios. Further preferably, M ≤ 500 g, and at this time, very good tracking effects can also be achieved for game scenarios with relatively intense movements. It is found through actual measurement and verification that when M = 200 g, ideal tracking effects can be achieved for game scenarios with relatively complex movements. If the mass is further reduced, the tracking effect will be more excellent.

[0089] Different from ordinary holographic projectors, holographic projectors are often not in a stationary state during operation. For example, in a geometric holographic display system, in order to follow the movement of the user and keep the viewing window always covering the user's eyes, the holographic projector needs to be in a moving state. Generally, the larger S0 is, the larger the corresponding viewing window coverage area is, and the easier it is to track; while the larger M is, the greater the inertia is, and the more difficult it is to track. Theoretical analysis and experimental verification show that when When the mass density of the holographic projector The unit is M is the total mass of the holographic projector, in kg. A more practical geometric holographic display system is designed, especially for application scenarios with less movement such as watching movies. Further, for learning and office scenarios, it is suitable to meet when it is more appropriate; for ordinary game scenarios, it is suitable to meet when it is more appropriate; for highly competitive games with intense movement, it is suitable to meet when it is more appropriate. When the above constraints are not met, tracking will be very difficult, and even office scenario applications cannot be used normally.

[0090] Preferably, the mass density ρ of the holographic projector M satisfies:

[0091]

[0092] In addition to the constraints on mass, the volume effect of the holographic projector also needs to be considered. An overly large volume requires more space during movement on the one hand, and on the other hand, effects such as wind resistance will be more obvious, resulting in greater driving energy consumption and lower control accuracy. Therefore, the minimum rectangular outer envelope volume V of the holographic projector min ≤1800 cm 3 , at this time, it can have better performance for the movie-watching scenario; further, for office and learning scenarios with slightly more movement, it is preferred that the minimum rectangular outer envelope volume V min ≤450 cm 3 ; for ordinary game scenarios, it is preferred that the minimum rectangular outer envelope volume V min ≤240 cm 3 ; for competitive games, generally with more movement, so if such application scenarios are included, it is further preferred that the minimum rectangular outer envelope volume V min ≤150 cm 3 .

[0093] It should be noted that the minimum rectangular parallelepiped refers to the rectangular parallelepiped with the smallest volume among the rectangular parallelepipeds that can enclose the holographic projector, and the volume of this rectangular parallelepiped is the minimum rectangular outer envelope volume. In actual situations, when the holographic projector is used in specific products, there may be multiple usage scenarios, rather than being limited to a single scenario. When designing, the design constraints are based on the scenario with the largest amount of movement among multiple usage scenarios, so as to meet the needs of multiple scenarios at the same time. For example, if the user has both movie-watching and learning / office needs, then the office scenario has more movement, so using the office scenario as the design constraint can meet the needs of both scenarios at the same time.

[0094] Although the above descriptions are all given by taking a single-viewpoint holographic projector as an example, they are equally applicable to multi-viewpoint holographic projectors. For example, two holographic projectors that meet the above constraints can be integrated together to form a dual-viewpoint holographic projector.

[0095] The present invention also discloses a holographic display system, including a holographic screen and a projection device, and the projection device is the holographic projector of any one of the above. Since the above projection device has the above beneficial effects, the holographic display system including this holographic projector has corresponding effects, which will not be elaborated here.

[0096] The above holographic display system is a geometric holographic display system or an in-situ holographic display system.

[0097] When it is a geometric holographic display system, the holographic screen is a transmissive geometric holographic screen or a reflective geometric holographic screen.

[0098] As Figure 4 shown, in the geometric holographic display system, the holographic screen 200 is a transmissive geometric holographic screen, and this display system can also be called a transmissive geometric holographic display system, including a transmissive geometric holographic screen and a display device. The display device uses the holographic projector 100 of the present invention, and the image projected by it is a divergent image and cannot be directly viewed by the user. The transmissive geometric holographic screen is a holographic screen that can re-convert the divergent image into an image converging to a fixed position (viewing window), so that the user can view at the viewing window. In order to implement the interaction function, an interaction device can also be added to the system. For non-wearable scenarios, users are prone to move out of the viewing window during movement. At this time, a tracking device can be added to the system to make the viewing window follow the movement of the user, so as to ensure the normal use of the user.

[0099] As Figure 5 shown, in the geometric holographic display system, the holographic screen 200 is a reflective geometric holographic screen, and this display system can also be called a reflective geometric holographic display system, including a reflective geometric holographic screen, a beam splitter screen and a display device. The display device uses the holographic projector 100 of the present invention, and the image projected by it is a divergent image and cannot be directly viewed by the user. The combined action of the reflective geometric holographic screen and the beam splitter screen can re-convert the divergent image into an image converging to a fixed position (viewing window), so that the user can view at the viewing window. In order to implement the interaction function, an interaction device (such as gesture recognition, facial expression recognition, action recognition, etc.) can also be added to the system. For non-wearable scenarios, users are prone to move out of the viewing window during movement. At this time, a tracking device can be added to the system to make the viewing window follow the movement of the user, so as to ensure the normal use of the user.

[0100] There are multiple implementation schemes for transmissive geometric holographic display systems and reflective geometric holographic display systems, and the flexibility of the optical path configuration is relatively high. For example, folding mirror groups can be used in special scenarios. Multiple implementation schemes have been disclosed in the previous patents of the research team of the present invention, and will not be elaborated here.

[0101] In addition, there are also multiple implementation methods for transmissive geometric holographic screens. As long as the holographic screen can convert the image points on one side to form conjugate real image points on the other side in terms of function, it can be used as a transmissive geometric holographic screen. Preferably, a holographic screen including an orthogonal mirror group array is used. There are also multiple implementation methods for reflective geometric holographic screens. As long as the holographic screen can achieve the retroreflective function, it can be used as a reflective geometric holographic screen. There are a large number of reference materials on the specific implementation methods of transmissive / reflective geometric holographic screens, such as microstructural details, and will not be elaborated here.

[0102] As Figure 6 shown, when it is a on-site holographic display system, the light source of the holographic projector 100 uses a coherent light source 300. The projection light of the holographic projector 100 irradiates on the holographic screen 200, and interferes with the projection light of the coherent light source 300 on the holographic screen 200, and an interference pattern of light and dark stripes is formed on the holographic screen 200. Light passes through the bright stripes in the interference pattern, and no light passes through the dark stripes, so the interference pattern itself can be regarded as a light field modulator. After the projection light of the coherent light source 300 is modulated by the interference pattern, a conjugate image of the projected 3D image is formed behind the holographic screen 200.

[0103] In addition to being applicable to holographic display systems, the holographic projector of the present invention can also be used in fields such as AR / VR and teaching demonstrations.

[0104] As Figures 7 to 10 shown, the following is an example of a holographic display system of the present invention for introduction. The holographic display system includes a base 500, a support rod 400, a holographic projector 100, and a holographic screen 200. The holographic projector 100 adopts a binocular form to achieve two-window display, corresponding to the user's two eyes for the user to view the display image with both eyes.

[0105] The support rod 400 is divided into two sections. The connection part between the support rod 400 and the base 500 can achieve rotation and / or up-and-down pitching motion; the up-and-down pitching motion can be achieved between the two connecting rods; the connection part between the upper connecting rod and the holographic projector 100 can achieve the left-and-right swinging and up-and-down pitching motion of the holographic projector 100; the connection part between the holographic screen 200 and the base 500 can achieve up-and-down pitching motion;

[0106] Furthermore, an eye tracking module and an interactive motion capture module can be set on the base 500 or other positions to facilitate user use and interaction.

[0107] Finally, it should also be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0108] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For the relevant parts, reference can be made to the description in the method section.

[0109] Those skilled in the art can further realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed in this text can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of the examples have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Skilled professionals can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0110] The steps of the methods or algorithms described in combination with the embodiments disclosed in this text can be directly implemented by hardware, software modules executed by a processor, or a combination of the two. The software modules can be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the technical field.

[0111] The foregoing description of the disclosed embodiments enables those skilled in the art to practice or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A holographic projector, comprising an imaging chip disposed inside the holographic projector for providing an equivalent image plane, a light source for providing light to the imaging chip, and an imaging lens group corresponding to the equivalent image plane and used for optical imaging, characterized in that, The power density ρ of the light source P satisfies: Among them, the power density of the light source in the unit of P is the light source power, with the unit of W; S0 is the aperture area of the light-transmitting hole of the outermost lens in the imaging lens group, with the unit of m 2 ; S 10 is the area of the light spot projected by the holographic projector on the plane perpendicular to the principal optical axis of the outermost lens in the imaging lens group at a position 10 cm away from the outermost lens, with the unit of m 2 ; S 100 is the area of the light spot projected by the holographic projector on the plane perpendicular to the principal optical axis of the outermost lens in the imaging lens group at a distance of 100 cm from the outermost lens, with the unit of m 2 .

2. The holographic projector according to claim 1, wherein The power density ρ of the light source P satisfies:

3. The holographic projector according to claim 2, wherein, The power density ρ of the light source P satisfies:

4. The holographic projector according to claim 1, wherein The luminous flux density ρ of the light source L satisfies: wherein, the luminous flux density of the light source in the unit of L is the luminous flux of the holographic projector, with the unit of lm.

5. The holographic projector according to claim 1, characterized in that, The depth of field performance ability of the holographic projector ≥ 5 m.

6. The holographic projector according to claim 1, wherein The image plane density ρ of the holographic projector l satisfies: Among them, the image plane density unit n is the number of image planes, with the unit of 1; l is the depth value of the display space, with the unit of m.

7. The holographic projector according to claim 6, wherein The image plane density ρ of the holographic projector l Satisfies:

8. The holographic projector according to claim 7, characterized in that, The image plane density ρ of the holographic projector l satisfies:

9. The holographic projector according to any one of claims 1 to 8, characterized in that, The holographic projector is a self-cooling structure.

10. The holographic projector according to any one of claims 1 to 8, characterized in that, It further includes a volume scanning mechanism capable of performing volume scanning.

11. A holographic display system, comprising a holographic screen and a projection device, characterized in that: The projection device is the holographic projector described in any one of claims 1 to 10.

12. The holographic display system according to claim 11, wherein The holographic display system is a geometric holographic display system or an in-situ holographic display system.

13. The holographic display system according to claim 11, wherein The holographic screen is a transmissive geometric holographic screen or a reflective geometric holographic screen.

14. The holographic display system according to claim 13, wherein The light source of the holographic projector described uses a coherent light source.

15. The holographic display system according to claim 11, wherein It further includes a base and a support rod, and the support rod connects the holographic projector and the base.

16. The holographic display system according to claim 15, wherein, The support rod includes an upper connecting rod and a lower connecting rod. The upper connecting rod is connected to the holographic projector and can achieve the left-right swing and up-down pitching of the holographic projector; the lower connecting rod is connected to the base and can achieve rotation and / or up-down pitching.

17. The holographic display system according to claim 11, wherein It further includes an eye tracking module.

18. The holographic display system according to claim 11, wherein, It further includes an interactive action capture module.

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