A depth of field extension method and system for integrated imaging

Abstract

The application belongs to the technical field of three-dimensional display, and discloses a depth-of-field extension method and system for integral imaging. The method arranges a plurality of imaging devices with focal length-wavelength dependence on a micro display; in a first frame time, controls an element image area covered under each imaging device to display in a first color contrast relationship, and forms an image on a first depth plane; in a second frame time, controls the element image area covered under each imaging device to display in a second color contrast relationship, and forms an image on a second depth plane; and alternately displays the images on the two depth planes through time multiplexing. The depth of field can be extended, and high-quality imaging can be performed on two neutral depth planes.

Description

Technical Field

[0001] The present application relates to the field of three-dimensional display technology, and in particular to a depth-of-field extension method and system for integrated imaging. Background Art

[0002] Traditional flat-panel microdisplays, such as LCD televisions and computer microdisplays, primarily display images and information on a two-dimensional surface. However, this display method cannot provide viewers with depth information about the image and cannot leverage the human brain's ability to process visual information. Three-dimensional display technology can display information close to the real three-dimensional space. Compared to flat-panel microdisplays, it can provide corresponding depth information, giving viewers a more realistic sense of immersion. Traditional 3D microdisplays utilize the human eye's binocular parallax, providing both eyes with images with horizontal parallax, allowing the human eye to obtain depth information. However, this binocular parallax-based 3D microdisplay can cause convergence-accommodation conflict, causing viewers to experience discomfort such as excessive intraocular pressure, ciliary muscle fatigue, and dizziness. To address this issue, integrated imaging light field display technology has emerged with its unique advantages.

[0003] However, each microlens in the current light field display system has a certain focal depth, which means that the reconstructed image of the light field display is only clear on the neutral depth plane (CDP). If the reconstructed depth plane (RDP) is far away from the neutral depth plane, the divergent light beam will cause the resolution of the reconstructed image to decrease due to the effect of defocus. Summary of the Invention

[0004] To this end, embodiments of the present application provide a depth of field extension method and system for integrated imaging, which achieves extended depth of field and high-definition imaging on two depth planes.

[0005] In a first aspect, the present application provides a depth of field extension method for integrated imaging.

[0006] This application is achieved through the following technical solutions:

[0007] A depth of field extension method for integrated imaging, the method comprising:

[0008] Arranging a plurality of imaging devices with focal length-wavelength dependence on a microdisplay;

[0009] During a first frame time, the element image area covered by each imaging device is controlled to be displayed in a first color contrast relationship and imaged on a first depth plane;

[0010] During the second frame time, the element image area covered by each imaging device is controlled to be displayed in a second color contrast relationship and imaged on a second depth plane;

[0011] The images on the two depth planes are displayed alternately through time multiplexing.

[0012] In a preferred example of the present application, it can be further configured that the imaging device includes any one of a super lens, a liquid crystal lens or a Fresnel zone plate.

[0013] In a preferred example of the present application, the step of arranging a plurality of imaging devices having focal length-wavelength dependence on the microdisplay includes:

[0014] Four imaging devices of the same type but different focal lengths are taken as a period and are horizontally arranged on the micro display in the order of a first imaging device, a second imaging device, a third imaging device, and a fourth imaging device.

[0015] In a preferred example of the present application, the step of arranging a plurality of imaging devices having focal length-wavelength dependence on the microdisplay includes:

[0016] Four imaging devices of the same type but different focal lengths are used as a cycle and are vertically arranged on the microdisplay in the order of a first imaging device, a second imaging device, a third imaging device, and a fourth imaging device.

[0017] In a preferred example of the present application, the step of arranging a plurality of imaging devices having focal length-wavelength dependence on the microdisplay includes:

[0018] Four imaging devices of the same type but different focal lengths are used as a cycle and are arranged in a square on the microdisplay in the order of a first imaging device, a second imaging device, a third imaging device, and a fourth imaging device.

[0019] In a preferred example of the present application, it can be further configured that, in the first frame time, the step of controlling the element image area covered by each imaging device to be displayed in the first color contrast relationship includes:

[0020] Setting the element image areas covered by the first imaging device, the second imaging device, and the third imaging device to display red, green, and blue respectively; and setting the element image area covered by the fourth imaging device to display no image;

[0021] The focal length of the first imaging device for red light, the focal length of the second imaging device for green light, and the focal length of the third imaging device for blue light are the same.

[0022] In a preferred example of the present application, it can be further configured that the step of imaging on the first depth plane includes:

[0023] The three monochrome surface pixels of red, green and blue in the first frame time are combined into a color volume pixel, and the color volume pixel is imaged on the first depth plane.

[0024] In a preferred example of the present application, it can be further configured that, in the second frame time, the step of controlling the element image area covered by each imaging device to be displayed in the second color contrast relationship includes:

[0025] The element image areas covered by the first imaging device, the second imaging device, and the fourth imaging device display green, blue, and red respectively; the element image area covered by the third imaging device does not display an image;

[0026] The focal length of the first imaging device for green light, the focal length of the second imaging device for blue light, and the focal length of the fourth imaging device for red light are the same.

[0027] In a preferred example of the present application, it can be further configured that the step of imaging on the second depth plane includes:

[0028] The three monochrome surface pixels of red, green and blue in the second frame time are combined into a color volume pixel, and the color volume pixel is imaged on the second depth plane.

[0029] In a second aspect, the present application provides a depth of field extension system for integrated imaging.

[0030] This application is achieved through the following technical solutions:

[0031] A depth of field extension system for integrated imaging, the depth of field extension system being configured to execute the depth of field extension method according to the first aspect, the system comprising:

[0032] An imaging device arrangement module, used for arranging a plurality of imaging devices with focal length-wavelength dependence on a microdisplay;

[0033] A first color control module is configured to control, during a first frame time, an element image area covered by each imaging device to be displayed in a first color contrast relationship and to form an image on a first depth plane;

[0034] A second color control module is used to control, during a second frame time, the element image area covered by each imaging device to be displayed in a second color contrast relationship and to form an image on a second depth plane;

[0035] The composite image module is used to alternately display the images on the two depth planes through time multiplexing.

[0036] In summary, compared with the prior art, the technical solutions provided by the embodiments of the present application have at least the following beneficial effects:

[0037] The present application arranges a number of imaging devices with focal length-wavelength dependence on a microdisplay; in the first frame time, controls the element image area covered by each imaging device to be displayed with a first color contrast relationship, and images are formed on the first depth plane; in the second frame time, controls the element image area covered by each imaging device to be displayed with a second color contrast relationship, and images are formed on the second depth plane; and alternately displays the images on the two depth planes through time multiplexing. The depth of field extension method proposed in the present application does not require the addition of light control devices to the conventional integrated imaging light field display system. It only requires replacing the traditional microlens array with imaging devices that are focal length and wavelength dependent, and utilizing the imaging devices at two neutral depth planes. At the same time, dispersion-free full-color display is achieved through two different combinations of imaging devices in the array. This can achieve the purpose of extending the depth of field of integrated imaging without increasing the complexity of the display system, and can keep the display system simple and thin in structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of a conventional integrated imaging system provided in one embodiment of the present application;

[0039] Figure 2 A schematic flow chart of a depth-of-field extension method for integrated imaging provided in one embodiment of the present application;

[0040] Figure 3 A schematic diagram of the horizontal arrangement of imaging devices and corresponding display colors provided in one embodiment of the present application;

[0041] Figure 4 A schematic diagram of the vertical arrangement of imaging devices and corresponding display colors provided by an embodiment of the present application;

[0042] Figure 5 Schematic diagram of a square arrangement of imaging devices and corresponding display colors provided in one embodiment of the present application

[0043] Figure 6 A schematic diagram of imaging at two depth planes provided by an embodiment of the present application;

[0044] Figure 7 A schematic structural diagram of a depth of field extension device for integrated imaging is provided for one embodiment of the present application;

[0045] Description of reference numerals:

[0046] Microdisplay-1, microlens array-2, eye box-3, reconstructed scene-4, imaging device arrangement module-01, first color control module-02, second color control module-03, synthetic image module-04. DETAILED DESCRIPTION

[0047] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

[0048] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are 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.

[0049] In addition, the term "and / or" in this application is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application, unless otherwise specified, generally indicates that the related objects are in an "or" relationship.

[0050] In this application, the terms "first", "second", etc. are used to distinguish identical or similar items with substantially the same effects and functions. It should be understood that there is no logical or temporal dependency between "first", "second", and "nth", nor is there any limitation on the quantity and execution order.

[0051] In traditional integrated imaging optical display systems, there is generally a micro display and a micro lens array. The micro lens array is one of the key imaging components. It is an optical element formed by arranging and combining multiple micro lenses with micron-level apertures in a specific way. Figure 1 As shown, a micro-lens array 2 is arranged in front of a micro-display 1. Micro-display 1 is responsible for presenting images or video content with high resolution and clear image quality. The images provided by micro-display 1 are the foundation for the subsequent 3D visual effect. By displaying an array of elemental images on micro-lens array 2, the light field distribution of a three-dimensional object can be reconstructed. In the figure, 3 represents the eye box, which refers to the range of human eye activity that allows for the clearest image when aligned with the center of the optical module. 4 represents the reconstructed scene.

[0052] It should be noted that according to Gauss's formula Where f represents the focal length of the microlens, g represents the distance between the microdisplay and the microlens array, and l represents the image distance. When the distance g between the microdisplay and the microlens array is greater than the focal length f of the microlenses, the display system is a real image system. Conversely, when the distance g between the microdisplay and the microlens array is less than the focal length f of the microlenses, the display system is a virtual image system. In a practical integrated imaging system, the sampling light for each pixel is a beam. Under the focusing action of the microlenses, the beams converge on the Gaussian image plane, which is the neutral depth plane. The volume pixel constructed on the neutral depth plane is the smallest.

[0053] The embodiments of the present application are described in further detail below with reference to the accompanying drawings.

[0054] like Figure 2 As shown, the depth of field extension method for integrated imaging proposed in this application includes:

[0055] S10: Arrange several imaging devices with focal length-wavelength dependence on a microdisplay.

[0056] An imaging device is arranged in correspondence with each element image area of ​​the element graphic array of the microdisplay. In the present application, imaging devices with specific focal length-wavelength dependence are selected to replace the traditional microlens array. The focal length of these imaging devices with focal length-wavelength dependence changes with the change of the wavelength of the incident light, so that different image distances can be achieved at different wavelengths. The microdisplay in the present application can be any one of an OLED display, an LCD display, and a micro-LED display. The focal length of these imaging devices changes with the wavelength of the incident light, so different image distances can be achieved for light of different wavelengths, and they can flexibly respond to light in different spectral ranges, thereby optimizing the imaging quality; at the same time, there is no need to use additional wavelength selection or focal length adjustment components, which simplifies the structure of the entire imaging system and helps reduce the complexity of production costs and manufacturing costs.

[0057] S20: During the first frame time, the element image area covered by each imaging device is controlled to be displayed in a first color contrast relationship, and to be imaged on a first depth plane.

[0058] The code calculates the elemental image array displayed on the microdisplay, determines the mapping relationship between each elemental image area in the elemental image array and the imaging device, and numbers the imaging devices. The elemental image areas corresponding to all imaging devices with the same number display the same color, thereby setting the focal length of the imaging devices with the same number to be the same. Elemental image areas corresponding to imaging devices with different numbers display different colors, and the mapping relationship between the imaging devices and the colors satisfies the first color mapping relationship. The colors of the elemental image areas are then imaged on the first depth plane during the first frame time.

[0059] S30: During the second frame time, the element image area covered by each imaging device is controlled to be displayed in a second color contrast relationship, and to be imaged on a second depth plane.

[0060] The code calculates the elemental image array displayed on the microdisplay, and the imaging devices are numbered, so that all elemental image areas corresponding to the same imaging device display the same color, while elemental image areas corresponding to different imaging devices display different colors. The mapping relationship between each elemental image area in the elemental image array and the imaging device is the same as in step S20. However, during the second frame time, the mapping relationship between the imaging device and the color satisfies the second color mapping relationship. Furthermore, during the second frame time, the colors of all the aforementioned elemental image areas are imaged on the second depth plane.

[0061] S40: Displaying the images on the two depth planes alternately through time multiplexing.

[0062] By controlling electronic or optical signals to quickly switch the display content of the element image area, the image is imaged at the first depth plane in the first frame time, the image is imaged at the second depth plane in the second frame time, the image is imaged at the first depth plane in the third frame time, and the image is imaged at the second depth plane in the fourth frame time, and the images are displayed alternately in sequence. Compared to using multiple independent displays or imaging systems to display images at different depth planes, time multiplexing technology can reduce hardware costs to a certain extent because it allows fewer physical components to be used to simulate more visual levels.

[0063] In some embodiments, an imaging device with wavelength-dependent focal length includes any one of a metalens, a liquid crystal lens, or a Fresnel zone plate. A metalens utilizes the phase modulation capability of a metasurface. By controlling the phase delay of incident light by a nanostructure, the light waves constructively interfere at a specific location, forming a focal point. Because different wavelengths of light experience different phase delays within the same structure, the focal length also varies with wavelength. A liquid crystal lens is composed of liquid crystal molecules. The arrangement of these molecules determines the refractive index distribution of the lens, which in turn directly affects the focal length of the lens. By precisely controlling the magnitude and direction of the electric field, the arrangement of the liquid crystal molecules can be precisely controlled, thereby precisely adjusting the focal length. A Fresnel zone plate utilizes the principle of light diffraction to form an image, forming a focal point by blocking or transmitting light waves in a specific area. Because different wavelengths of light have different diffraction angles on the zone plate, the resulting focal point position also varies, meaning that the focal length varies with wavelength.

[0064] Optionally, in step S10, four imaging devices of the same type but different focal lengths are arranged horizontally on the microdisplay in the order of a first imaging device, a second imaging device, a third imaging device, and a fourth imaging device. Specifically, the four imaging devices in each cycle are numbered as imaging device ①, imaging device ②, imaging device ③, and imaging device ④, such as Figure 3 As shown in a, they are arranged horizontally, and each row is arranged in the order of imaging device ①-imaging device ②-imaging device ③-imaging device ④.

[0065] In step S20, in the first frame time, controlling the element image area covered by each imaging device to display in the first color contrast relationship includes: setting the element image area covered by the first imaging device, the second imaging device, and the third imaging device to display red, green, and blue respectively; it should be noted that the focal length of the first imaging device for red light is the same as the focal length of the second imaging device for green light and the focal length of the third imaging device for blue light. The element image area covered by the fourth imaging device does not display an image. Figure 3 As shown in Figure b, all element image areas covered by the first imaging device ① display red, all element image areas covered by the second imaging device ② display green, all element image areas covered by the third imaging device ③ display blue, and all element image areas covered by the fourth imaging device ④ do not display an image, or in other words, do not display a color, that is, display a black image. The imaging device ④ does not participate in the imaging of the first frame time, which can ensure that the first imaging device ①, the second imaging device ②, and the third imaging device ③ synthesize red, blue, and green light into a color image without color difference at the same image distance.

[0066] Step S30, in the second frame time, controls the element image area covered by each imaging device to display in a second color contrast relationship, including: the element image areas covered by the first imaging device, the second imaging device, and the fourth imaging device display green, blue, and red respectively; it should be noted that the focal length of the first imaging device for green light is the same as the focal length of the second imaging device for blue light and the focal length of the fourth imaging device for red light. The element image area covered by the third imaging device does not display an image. Figure 3 As shown in Figure c, all element image areas covered by the first imaging device ① display green, all element image areas covered by the second imaging device ② display blue, all element image areas covered by the third imaging device ③ do not display an image, or in other words, do not display an image but display a black image, and all element image areas covered by the fourth imaging device ④ display red. Similarly, the third imaging device ③ does not participate in the imaging of the second frame time, which ensures that the first imaging device ①, the second imaging device ②, and the fourth imaging device ④ synthesize green, blue, and red into a color image without color difference at the same image distance. It should be noted that Figure 3b and Figure 3 In c, R stands for Red, G stands for Green, B stands for Blue, and K stands for Blank.

[0067] Optionally, in step S10, four imaging devices of the same type but different focal lengths are used as a cycle and are arranged vertically on the microdisplay in the order of a first imaging device, a second imaging device, a third imaging device, and a fourth imaging device. Specifically, the four imaging devices in each cycle are numbered as first imaging device ①, second imaging device ②, third imaging device ③, and fourth imaging device ④, such as Figure 4 As shown in a, they are arranged vertically, and each column is arranged in the order of first imaging device ① - second imaging device ② - third imaging device ③ - fourth imaging device ④.

[0068] In step S20, in the first frame time, controlling the element image area covered by each imaging device to display in the first color contrast relationship includes: setting the element image area covered by the first imaging device, the second imaging device, and the third imaging device to display red, green, and blue respectively; and the element image area covered by the fourth imaging device does not display an image. Figure 4 As shown in b, all element image areas covered by the first imaging device ① display red, all element image areas covered by the second imaging device ② display green, all element image areas covered by the third imaging device ③ display blue, and all element image areas covered by the fourth imaging device ④ do not display an image. In other words, the fourth imaging device ④ displays black.

[0069] Step S30, in the second frame time, controls the element image area covered by each imaging device to display in the second color contrast relationship, including: the element image area covered by the first imaging device, the second imaging device, and the fourth imaging device displays green, blue, and red respectively; the element image area covered by the third imaging device does not display an image. Figure 4 As shown in Figure c, all element image areas covered by the first imaging device ① display green, all element image areas covered by the second imaging device ② display blue, all element image areas covered by the third imaging device ③ do not display an image and may display black, and all element image areas covered by the fourth imaging device ④ display red. It should be noted that Figure 4 b and Figure 4 In c, R stands for Red, G stands for Green, B stands for Blue, and K stands for Blank.

[0070] Optionally, in step S10, four imaging devices of the same type but different focal lengths are used as a cycle and are arranged in a square on the microdisplay in the order of a first imaging device, a second imaging device, a third imaging device, and a fourth imaging device. Specifically, the four imaging devices in each cycle are numbered as first imaging device ①, second imaging device ②, third imaging device ③, and fourth imaging device ④, as shown in FIG. Figure 5 As shown in a, a square arrangement is performed, in each square, the first imaging device ① is arranged in the first quadrant, the second imaging device ② is arranged in the second quadrant, the third imaging device ③ is arranged in the third quadrant, and the fourth imaging device ④ is arranged in the fourth quadrant.

[0071] In step S20, in the first frame time, controlling the element image area covered by each imaging device to display in the first color contrast relationship includes: setting the element image area covered by the first imaging device, the second imaging device, and the third imaging device to display red, green, and blue respectively; and the element image area covered by the fourth imaging device does not display an image. Figure 5 As shown in b, all element image areas covered by the first imaging device ① display red, all element image areas covered by the second imaging device ② display green, all element image areas covered by the third imaging device ③ display blue, and all element image areas covered by the fourth imaging device ④ do not display an image, or in other words, display a black image.

[0072] Step S30, in the second frame time, controls the element image area covered by each imaging device to display in the second color contrast relationship, including: the element image area covered by the first imaging device, the second imaging device, and the fourth imaging device displays green, blue, and red respectively; the element image area covered by the third imaging device does not display an image. Figure 5 As shown in Figure c, all element image areas covered by the first imaging device ① display green, all element image areas covered by the second imaging device ② display blue, all element image areas covered by the third imaging device ③ display no image, or in other words, display a black image, and all element image areas covered by the fourth imaging device ④ display red. It should be noted that Figure 5 b and Figure 5 In c, R stands for Red, G stands for Green, B stands for Blue, and K stands for Blank.

[0073] In some embodiments, the step of imaging on the first depth plane in step S20 includes: combining three monochrome surface pixels of red, green, and blue in the first frame time into a color body pixel, and imaging the color body pixel on the first depth plane.

[0074] The step of imaging on the second depth plane in step S30 includes: combining three monochrome surface pixels of red, green and blue in the second frame time into a color volume pixel, and imaging the color volume pixel on the second depth plane.

[0075] Assume that the focal lengths of the first imaging device, the second imaging device, the third imaging device, and the fourth imaging device corresponding to red, green, and blue are represented by f 1R 、f 1G 、f 1B , f 2R 、f 2G 、f 2B , f 3R 、f 3G 、f 3B , f 4R 、f 4G 、f 4B When f1=f 1R =f 2G =f 3B , f2=f 1G =f 2B =f 4R , when the object distance g is fixed, according to Gauss's formula It can be seen that l1=l 1R =l 2G =l 3B , l2=l 1G =l 2B =l 4R That is, the imaging positions corresponding to the red, green and blue wavelengths of the first imaging device, the second imaging device and the third imaging device are at the same depth l1; the imaging positions corresponding to the green, blue and red wavelengths of the first imaging device, the second imaging device and the fourth imaging device are at the same depth l2.

[0076] Therefore, in the first frame time, the element image areas covered by the three imaging devices are made to display different colors (ie, red, green, and blue), and the imaging positions are made to be at the same depth. Figure 6 In a, the element image areas covered by the first imaging device ①, the second imaging device ②, and the third imaging device ③ are respectively displayed in red, green, and blue colors, and the display area covered by the fourth imaging device ④ does not display an image. The three monochrome surface pixels of red, green, and blue can be combined into a color volume pixel, and the imaging position is placed on the same depth plane RDP1; the second frame time, such as Figure 6As shown in Figure 2b, the display areas covered by the first, second, and fourth imaging devices (①, ②, and ④) display green, blue, and red images, respectively, while no image is displayed below the third imaging device (③). This allows for a color image to be synthesized on the depth plane RDP2. This allows corresponding images to be displayed on two different depth planes, thereby extending the depth of field of the integrated imaging light field display.

[0077] This application uses four imaging devices of the same type but different focal lengths as a cycle, such as a superlens array. Then, by rapidly switching the element image array, two images at different depths are reconstructed in two frames. By utilizing the persistence of vision of the human eye, that is, through time multiplexing, the human eye can perceive the images at two depths, thereby extending the depth of field of the integrated imaging light field display. The method proposed in this application is applicable to both virtual and real image systems.

[0078] In another embodiment of the present application, a depth of field extension system for integrated imaging is also provided, and the depth of field extension system is used to perform the above-mentioned depth of field extension method, such as Figure 7 As shown, the depth of field extension system includes: an imaging device arrangement module 01, a first color control module 02, a second color control module 03, and a synthetic image module 04;

[0079] Imaging device arrangement module 01, used to arrange a plurality of imaging devices with focal length-wavelength dependence on the micro display;

[0080] The first color control module 02 is used to control the element image area covered by each imaging device to be displayed in a first color contrast relationship in a first frame time, and to form an image on a first depth plane;

[0081] The second color control module 03 is used to control the element image area covered by each imaging device to be displayed in a second color contrast relationship in the second frame time, and to form an image on the second depth plane;

[0082] The composite image module 04 is configured to alternately display the images on the two depth planes through time multiplexing.

[0083] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] Those skilled in the art will clearly understand that for the sake of convenience and brevity of description, the division of the above-mentioned functional units and modules is only used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the system described in this application is divided into different functional units or modules to complete all or part of the functions described above.

Claims

1. A depth of field extension method for integrated imaging, characterized in that: The method comprises: Four imaging devices of the same type but with different focal lengths and having focal length-wavelength dependence are used as a cycle, and a first imaging device, a second imaging device, a third imaging device, and a fourth imaging device are arranged on the microdisplay in a preset arrangement; During a first frame time, controlling the element image area covered by each imaging device to be displayed in a first color contrast relationship and imaging on a first depth plane, wherein the display in the first color contrast relationship is such that the element image areas covered by the first imaging device, the second imaging device, and the third imaging device display red, green, and blue, respectively, and the element image area covered by the fourth imaging device does not display an image, and the focal length of the first imaging device for red light, the focal length of the second imaging device for green light, and the focal length of the third imaging device for blue light are the same; During a second frame time, the element image area covered by each imaging device is controlled to be displayed in a second color contrast relationship, and imaged on a second depth plane, wherein the display in the second color contrast relationship is that the element image areas covered by the first imaging device, the second imaging device, and the fourth imaging device are respectively displayed in green, blue, and red; the element image area covered by the third imaging device does not display an image, and the focal length of the first imaging device for green light, the focal length of the second imaging device for blue light, and the focal length of the fourth imaging device for red light are the same; The images on the two depth planes are displayed alternately through time multiplexing.

2. The depth of field extension method for integrated imaging according to claim 1, characterized in that: The imaging device includes any one of a super lens, a liquid crystal lens or a Fresnel zone plate.

3. The depth of field extension method for integrated imaging according to claim 1, characterized in that: The preset layouts include: The first imaging device, the second imaging device, the third imaging device and the fourth imaging device are horizontally arranged on the micro display in this order.

4. The depth of field extension method for integrated imaging according to claim 1, characterized in that: The preset layouts include: The first imaging device, the second imaging device, the third imaging device and the fourth imaging device are arranged vertically on the micro display in this order.

5. The depth of field extension method for integrated imaging according to claim 1, characterized in that: The preset layouts include: The first imaging device, the second imaging device, the third imaging device and the fourth imaging device are arranged in a square in this order on the micro display.

6. The depth of field extension method for integrated imaging according to claim 1, characterized in that: The step of imaging on the first depth plane comprises: The three monochrome surface pixels of red, green and blue in the first frame time are combined into a color volume pixel, and the color volume pixel is imaged on the first depth plane.

7. The depth of field extension method for integrated imaging according to claim 1, characterized in that: The step of imaging on the second depth plane comprises: The three monochrome surface pixels of red, green and blue in the second frame time are combined into a color volume pixel, and the color volume pixel is imaged on the second depth plane.

8. A depth of field extension system for integrated imaging, characterized in that: The depth of field extension system is used to perform the depth of field extension method according to any one of claims 1 to 7, and the system includes: An imaging device arrangement module is used to arrange four imaging devices of the same type but different focal lengths with focal length-wavelength dependence as a cycle, and to arrange a first imaging device, a second imaging device, a third imaging device, and a fourth imaging device on the microdisplay in a preset arrangement; a first color control module, configured to control, during a first frame time, an elemental image area covered by each imaging device to be displayed in a first color contrast relationship and to form an image on a first depth plane; wherein the display in the first color contrast relationship is such that the elemental image areas covered by the first imaging device, the second imaging device, and the third imaging device are displayed in red, green, and blue, respectively, and the elemental image area covered by the fourth imaging device is not displayed; and the focal length of the first imaging device for red light, the focal length of the second imaging device for green light, and the focal length of the third imaging device for blue light are the same; a second color control module, configured to control, during a second frame time, an elemental image area covered by each imaging device to be displayed in a second color contrast relationship and to form an image on a second depth plane; wherein the display in the second color contrast relationship is such that the elemental image areas covered by the first imaging device, the second imaging device, and the fourth imaging device are displayed in green, blue, and red, respectively; the elemental image area covered by the third imaging device is not displayed, and the focal length of the first imaging device for green light, the focal length of the second imaging device for blue light, and the focal length of the fourth imaging device for red light are the same; The composite image module is used to alternately display the images on the two depth planes through time multiplexing.

Images