CN108803054B - 3D light field display system - Google Patents

Abstract

The embodiment of the invention provides a 3D light field display system, which comprises a 2D image generating device and a composite grating; the 2D image generation device is used for projecting a 2D image to the composite grating; the composite grating is a grating structure provided with a cylindrical lens at a slit of the slit grating, and is used for providing a light field with a stereoscopic effect for a 2D image projected by the 2D image generating device so as to form a 3D image. According to the system provided by the embodiment of the invention, the composite grating of the cylindrical lens is arranged at the slit of the slit grating, so that the problem that the resolution is reduced when the viewing angle is increased in the conventional 3D light field display system is solved, and the reduction of the resolution caused by the increase of the pitch is avoided while the viewing angle is increased. Meanwhile, compared with the traditional slit grating, the display brightness of the 3D image is improved.

Description

A 3D light field display system

technical field

Embodiments of the present invention relate to the technical field of light field display, and in particular, to a 3D light field display system.

Background technique

With the rapid development of science and technology, naked-eye 3D display has become the mainstream development trend in the display industry. Among them, naked-eye 3D display devices based on slit gratings or cylindrical lens gratings can construct viewpoints of three-dimensional objects at different positions in space. Due to its advantages of low cost and simple structure, naked-eye 3D display devices based on slit gratings or cylindrical lens gratings have a high degree of commercialization.

As shown in FIG. 1, the naked-eye 3D display system based on the slit grating 102, wherein the slit grating 102 plays the role of controlling light, and can guide the light emitted by the pixels on the 2D display screen 101 to different positions in space. The viewpoints in Fig. 1 refer to different side information of three-dimensional objects seen at different positions in space. However, the above display method has some defects. For example, an image synthesized by collecting 4 different side information of any 3D model contains the information of 4 viewpoints, so the resolution of each viewpoint will be reduced by 1/4. And because the slit grating blocks most of the light, the display method based on the slit grating has low brightness.

As shown in FIG. 2 , the naked-eye 3D display system based on the cylindrical lens grating 202 , here the function of the cylindrical lens grating 202 is the same as that of the slit grating 102 in FIG. 1 . However, because the cylindrical lens can transmit light, the brightness of the cylindrical lens grating 202 is higher than that of the slit grating 102. The principle is to control the light by using the refraction of the light when it passes through the cylindrical lens. However, the resolution of the above two display methods will also decrease with the increase of the viewpoint, and the viewing angle formed is θ=2arctanp/2g, where p is the pitch of the slit grating 102 or the cylindrical lens grating 202, and g is the The distance between the slit grating 102 or the cylindrical lens grating 202 from the 2D display screen 101 .

However, if the viewing angle is only increased by increasing the knot p, it will bring other negative effects, such as increasing the graininess and reducing the resolution. As shown in FIG. 3 , because the 2D display screen 101 is placed on the rear focal plane of the cylindrical lens 302 , the light emitted by the pixels will be a beam of parallel light with a width equal to the pitch of the cylindrical lens after passing through the cylindrical lens 302 , and the human eye 303 will pass through it. One cylindrical lens 302 can only see one pixel, so as the pitch of the cylindrical lens increases, the number of cylindrical lenses 302 decreases, so the resolution decreases.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a 3D light field display system, which is used to solve the problem that the resolution decreases when the viewing angle of the existing 3D light field display system is increased.

An embodiment of the present invention provides a 3D light field display system, including a 2D image generating device and a composite grating; wherein, the 2D image generating device is used to project a 2D image to the composite grating; The grating structure of the cylindrical lens and the composite grating are used to make the 2D image projected by the 2D image generating device form a light field with a three-dimensional effect, so as to form a 3D image.

The embodiment of the present invention provides a 3D light field display system. By arranging a composite grating of a cylindrical lens at the slit of the slit grating, it solves the problem that the existing 3D light field display system will reduce the resolution when the viewing angle is increased. It ensures that while increasing the viewing angle, the resolution will not be reduced due to the increase of the pitch. At the same time, compared with the traditional slit grating, the display brightness of the 3D image is improved.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a schematic diagram of a naked-eye 3D display system based on a slit grating in the prior art;

2 is a schematic diagram of a naked-eye 3D display system based on a cylindrical lens grating in the prior art;

3 is a schematic diagram of a naked-eye 3D display system based on a cylindrical lens grating in the prior art;

4 is a schematic structural diagram of a 3D light field display system according to an embodiment of the present invention;

5 is a schematic structural diagram of a composite grating in an embodiment of the present invention;

6 is a schematic structural diagram of a 3D light field display system according to an embodiment of the present invention;

in,

101-2D display screen; 102-slit grating; 202-cylindrical lens grating;

302-cylindrical lens; 303-human eye; 401-2D image generating device;

402-composite grating; 403-3D image; 501-cylindrical lens;

502-shading part; 601-first projector; 602-second projector;

603-Third projector; 604-Vertical diffusion film.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

FIG. 4 is a schematic structural diagram of a 3D light field display system according to an embodiment of the present invention. As shown in FIG. 4, a 3D light field display system includes a 2D image generating device 401 and a composite grating 402; The device 401 is used to project a 2D image to the composite grating 402; the composite grating 402 is a grating structure with cylindrical lenses arranged at the slits of the slit grating, and the composite grating 402 is used to make the 2D image projected by the 2D image generating device 401 form a three-dimensional image. effect light field to form a 3D image.

Specifically, the 2D image generating device 401 may be a 2D display screen or a device capable of projecting images to the outside, such as a projector, and the 2D image generating device 401 may be a single display screen or a projector, or multiple 2D display screens And/or the combination of projectors, the embodiment of the present invention does not specifically limit the type and quantity of the 2D image generating device 401 .

In addition, the composite grating 402 corresponds to a combination of a conventional slit grating and a cylindrical lens grating. FIG. 5 is a schematic structural diagram of a composite grating 402 in an embodiment of the present invention. As shown in FIG. 5 , the composite grating 402 is composed of a cylindrical lens 501 and a light shielding portion 502 . Compared with the slit grating composed of the light shielding portion 502 and the slits between the light shielding portions 502 , the composite grating 402 has an enlarged slit of the slit grating, and a cylindrical lens 501 is provided at the slit.

Further, in the embodiment of the present invention, the 2D image generating device 401 and the composite grating 402 work together to generate a 3D image.

In the embodiment of the present invention, by disposing the composite grating 402 of the cylindrical lens at the slit of the slit grating, the problem that the resolution is reduced when the viewing angle is increased in the existing 3D light field display system is solved, and the increase of the viewing angle is ensured. While the viewing angle is large, the resolution will not be reduced due to the increase of the pitch. At the same time, compared with the traditional slit grating, the display brightness of the 3D image is improved.

Based on the above embodiment, a 3D light field display system, the 2D image generating device 401 is arranged on the first plane, the composite grating 402 is arranged on the second plane, the first plane and the second plane are parallel, that is, the 2D image generating device 401 The plane in which it is located is parallel to the plane in which the composite grating 402 is located. Similarly, it can be known that the plane where the 2D image generating device 401 is located is parallel to the imaging plane where the 2D image generating device 401 emits the 2D image, the imaging plane where the 2D image generating device 401 emits the 2D image is parallel to the plane where the composite grating 402 is located.

In the embodiment of the present invention, by setting the first plane and the second plane to be parallel, it is helpful to improve the 3D image display effect of the 3D light field display system.

Based on any of the above embodiments, in a 3D light field display system, the 2D image generating device 401 is a projector array, the projector array includes a plurality of projectors, and the plurality of projectors are evenly and equidistantly arranged on a first surface of a first plane. in a straight line.

Among the above-mentioned projectors, each projector is used to project a 2D image to the composite grating 402 , and each projector emits directional light. Each projector is capable of projecting information from several viewpoints. In the above multiple projectors, the viewpoints corresponding to the information projected by any two projectors are different. In the projector array, before the 2D image projected by each projector is projected to the composite grating 402, the imaging surface of the projector array is formed, so the imaging surface of the projector array is located between the projector array and the composite grating 402, and any projector is imaged. faces are independent. Several in the embodiments of the present invention refer to one or more. Different side information of three-dimensional objects that can be seen by multiple viewpoints at different positions in space.

Further, in the embodiment of the present invention, by arranging the projectors at equal distances, the 2D image projected by the projector array can be evenly projected on the composite grating 402, so that the 3D light field display system proposed in the embodiment of the present invention can Provide better display effect.

In the embodiment of the present invention, by setting the projector array to include a plurality of projectors, it is possible to have a higher resolution and a wider viewing angle than the prior art under the condition of increasing viewpoints, which solves the problem of the prior art. The number of viewpoints and the resolution existing in the CCD form a mutually restrictive relationship, which can display 3D images with better effects.

Based on any of the above embodiments, in a 3D light field display system, the first straight line is parallel to the periodic structure of the composite grating. It should be noted that the composite grating has a periodic structure, and the directions in which the composite grating reflects, transmits and diffracts light are the same as the direction of the periodic structure.

Based on any of the above embodiments, a 3D light field display system further includes a vertical diffusion film, the vertical diffusion film is used to diffuse the light in the light field with a three-dimensional effect in a vertical direction; the vertical diffusion film is located on a third plane , the third plane is parallel to the first plane and the second plane; the first plane, the second plane and the third plane are arranged in sequence.

Specifically, the vertical diffusion film is obtained by the method of light interference, which can diffuse the light in the light field with the three-dimensional effect emitted by the composite grating 402 in the vertical direction by a preset angle, and does not prevent the above-mentioned light in the horizontal direction. Optics that make an impact. It should be noted that the diffusion angle of the vertical diffusion film may be determined according to the actual requirements of the 3D light field display system, which is not specifically limited in the embodiment of the present invention.

The operating principle of the 3D light field display system in the embodiment of the present invention is as follows:

First, the 2D image generating device 401 emits a 2D image and projects it on the composite grating 402 . Then, the 2D image projected by the 2D image generating device 401 passes through the composite grating 402 to form a light field with a three-dimensional effect. Next, after the light in the light field with the stereoscopic effect formed by the composite grating 402 is diffused by the vertical diffusion film at a predetermined angle in the vertical direction, a 3D image is formed.

In the embodiment of the present invention, by adding a vertical diffusion film, the problem of the small divergence angle of the 2D image light projected by the 2D image generating device is solved, and it is ensured that the viewer can watch the display of the 3D light field display system in the entire vertical direction. 3D images.

Based on any of the above embodiments, a 3D light field display system, the viewing angle of the 3D light field display system is:

为观看视角，N为投影仪阵列中的投影仪个数，p为复合光栅的节距，g为复合光栅与投影仪阵列成像面之间的距离。in,

For the viewing angle, N is the number of projectors in the projector array, p is the pitch of the composite grating, and g is the distance between the composite grating and the imaging surface of the projector array.

Specifically, multiple projectors jointly form multiple viewpoints in space. If the lateral resolution of the projectors is M, the resolution of the final displayed three-dimensional image is only reduced to M/N. Then the viewing angle of the 3D light field display system is also increased by N times.

In order to better understand and apply a 3D light field display system proposed by the present invention, the present invention provides the following examples, and the present invention is not limited to the following examples.

FIG. 6 is a schematic structural diagram of a 3D light field display system according to an embodiment of the present invention. As shown in FIG. 6 , the 3D light field display system includes a projector array, a composite grating 402 and a vertical diffusion film 604 .

The projector array is composed of three equally spaced projectors, and the 3D light field display system in this example has 18 viewpoints, and the image projected by each projector includes information of 6 viewpoints. Specifically, the 2D image projected by the first projector 601 includes information of viewpoints 13, 14, 15, 16, 17 and 18, and the 2D image projected by the second projector 602 includes viewpoints 7, 8, 9, 10, 11 and 18. 12, the 2D image projected by the third projector 603 includes the information of viewpoints 1, 2, 3, 4, 5 and 6.

Thus, after the 2D image projected by the first projector 601 passes through the composite grating 402 and the vertical diffusion film 602, viewpoints 13, 14, 15, 16, 17 and 18 are formed in space, and the 2D image projected by the second projector 602 After passing through the composite grating 402 and the vertical diffusion film 604, viewpoints 7, 8, 9, 10, 11 and 12 are formed in the space. After the 2D image projected by the third projector 603 passes through the composite grating 402 and the vertical diffusion film 604, the Viewpoints 1, 2, 3, 4, 5 and 6 are formed in the space. Thus, the above three projectors jointly construct a 3D image including 18 viewpoints in space.

If the horizontal resolution of the projector is M, the resolution of the final displayed 3D image only drops to M/6, which is 3 times higher than the traditional method. The viewing angle of the 3D light field display system in this example is:

It can be seen from the above that the viewing angle of the 3D light field display system in this example is increased by 3 times compared with the traditional light field display system.

Here, the arrangement of the projector array takes the three projectors in FIG. 6 as an example, and other numbers of projectors can be deduced by analogy. At the grating 402L+g, the 2D images projected by the above projections are all imaged at a distance L in the longitudinal direction of the projector array. The first projector 601 and the third projector 603 are in the lateral direction, and the distance from the second projector 602 is d=pL/g, where p is the pitch of the composite grating 402 .

In this example, by disposing the composite grating 402 of the cylindrical lens at the slit of the slit grating, the problem that the existing 3D light field display system will reduce the resolution when the viewing angle is increased is solved, and the problem of reducing the resolution will be solved when the viewing angle is increased. At the same time of viewing angle, the resolution will not decrease due to the increase of pitch. At the same time, compared with the traditional slit grating, the display brightness of the 3D image is improved.

Secondly, by setting the projector array to include a plurality of projectors, it is possible to have higher resolution and wider viewing angle than the prior art when the number of viewpoints increases, thereby solving the existing viewpoints in the prior art. The number and resolution form a mutually restrictive relationship, which can display 3D images with better effects.

Third, by arranging the projectors at equal distances, the 2D images projected by the projector array can be evenly projected on the composite grating 402, so that the 3D light field display system provided by the embodiments of the present invention can provide better display effects.

Finally, by adding the vertical diffusion film 604, the problem of the small divergence angle of the 2D image light projected by the 2D image generating device is solved, and it is ensured that the viewer can watch the 3D image displayed by the 3D light field display system in the entire vertical direction. .

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention, but not to limit them; although the embodiments of the present invention have been described in detail with reference to the foregoing embodiments, ordinary The skilled person should understand that it is still possible to modify the technical solutions described in the foregoing embodiments, or to perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the present invention. The scope of the technical solutions of the embodiments of each embodiment.

Claims (3)

1. A3D light field display system is characterized by comprising a 2D image generation device and a composite grating;

the 2D image generation device is used for projecting a 2D image to the composite grating;

the composite grating is a grating structure provided with a cylindrical lens at a slit of the slit grating, and the composite grating is used for enabling the 2D image projected by the 2D image generating device to form a light field with a three-dimensional effect so as to form a 3D image;

the 2D image generation device is arranged on a first plane, the composite grating is arranged on a second plane, and the first plane is parallel to the second plane;

the 2D image generation device is a projector array, the projector array comprises a plurality of projectors, and the projectors are uniformly and equidistantly arranged on a first straight line of the first plane;

the viewing angles of the 3D light field display system are:

wherein,

and in order to view the visual angle, N is the number of projectors in the projector array, p is the pitch of the composite grating, and g is the distance between the composite grating and the imaging surface of the projector array.

2. The system of claim 1, wherein the first line is parallel to a periodic structure of the composite grating.

3. The system of claim 1, further comprising a vertical diffuser film for diffusing light rays in the stereotactic light field in a vertical direction;

the vertical diffusion film is located on a third plane, and the third plane is parallel to the first plane and the second plane;

the first plane, the second plane and the third plane are arranged in sequence.

Images