Image acquisition system, image acquisition method thereof, and near-eye display glasses

Abstract

An image acquisition system, an image acquisition method thereof, and near-eye display glasses, relating to the field of near-eye display. During use, a first coupling input optical element reflects first imaging light from an eye side; a second coupling input optical element transmits the first imaging light or reflects second imaging light from a non-eye side; a coupling output optical element reflects the first imaging light or the second imaging light; then different imaging light is transferred to a camera sensor along corresponding optical paths to generate corresponding target images.

Description

Image acquisition system, image acquisition method and near-eye display glasses

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese Patent Application No. 202311779762.1 filed on December 21, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present invention relates to the field of near-eye display, and in particular to an image acquisition system and an image acquisition method thereof, and near-eye display glasses. Background Art

[0004] Near-eye display technology is an important technical support for realizing virtual reality (VR) and augmented reality (AR) experiences in the future. In recent years, it has received widespread attention and rapid development in both industry and academia.

[0005] Currently, image acquisition technology is widely used in near-eye display glasses. Generally speaking, according to actual needs, imaging light from different directions is transmitted along preset optical paths within an optical waveguide to corresponding camera sensors to generate the corresponding target image. However, the need for multiple camera sensors makes the glasses bulky and increases design costs. Therefore, it is necessary to provide a new image acquisition technology.

[0006] Summary of the Invention

[0007] (1) Technical problems solved

[0008] In response to the shortcomings of the existing technology, the present invention provides an image acquisition system and its image acquisition method and near-eye display glasses, which solve the technical problems of needing to set up multiple camera sensors, resulting in bloated glasses and increased design costs.

[0009] (2) Technical solution

[0010] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0011] An image acquisition system based on a geometric light waveguide lens includes a first coupling input optical element, a second coupling input optical element, a coupling output optical element and a camera sensor;

[0012] The first coupling-in optical element, the second coupling-in optical element, and the coupling-out optical element are all embedded in the geometric light waveguide lens, and the second coupling-in optical element is located between the first coupling-in optical element and the coupling-out optical element;

[0013] The camera sensor faces the geometric light waveguide lens and is close to the coupling output optical element;

[0014] The incident area of ​​the first imaging light originating from the eye side on the geometric light waveguide lens, the first coupling-input optical element, the second coupling-input optical element, the coupling-out optical element and the camera sensor constitute a first optical path;

[0015] The incident area of ​​the second imaging light originating from the non-eye side on the geometrical light waveguide lens, the second coupling-in optical element, the coupling-out optical element and the camera sensor constitute a second optical path.

[0016] In an example, the first coupling-in optical element is a first semi-transmissive and semi-reflective coating.

[0017] In an example, the first transflective coating is a first free-form surface, and the opening direction is toward the eye side.

[0018] In an example, the second coupling-in optical element is a second semi-transmissive and semi-reflective coating.

[0019] In an example, the second transflective coating is a second free-form surface, and the opening direction is toward the non-eye side.

[0020] In an example, the coupling-out optical element is a total reflection coating.

[0021] In an example, the total reflection coating is a planar coating.

[0022] An image acquisition method of the image acquisition system as described above, comprising:

[0023] The first imaging light originating from the eye side is reflected by the first coupling-in optical element and transmitted along the first optical path to the second coupling-in optical element;

[0024] The first imaging light is transmitted through the second coupling-in optical element and transmitted to the coupling-out optical element along the first optical path; or the second imaging light originating from the non-eye side is reflected through the second coupling-in optical element and transmitted to the coupling-out optical element along the second optical path;

[0025] Reflecting the first imaging light or the second imaging light through the coupling output optical element, and transmitting the light to the camera sensor along the first optical path or the second optical path accordingly;

[0026] After the camera sensor collects the first imaging light or the second imaging light, it generates a corresponding target image.

[0027] A pair of near-eye display glasses comprises the image acquisition system described above.

[0028] In an example, the camera sensor is located at an edge of a frame of the near-eye display glasses.

[0029] (3) Beneficial effects

[0030] The present invention provides an image acquisition system and method thereof, as well as near-eye display glasses, which eliminate the need for multiple camera sensors. Compared with the prior art, the present invention has the following advantages:

[0031] The present invention is based on a geometric light waveguide lens and includes a first coupling input optical element, a second coupling input optical element, a coupling output optical element, and a camera sensor. During use, the first coupling input optical element reflects a first imaging light originating from the eye side; the second coupling input optical element transmits the first imaging light or reflects a second imaging light originating from the non-eye side; and the coupling output optical element reflects the first imaging light or the second imaging light. This allows different imaging light rays to be transmitted along corresponding optical paths to the camera sensor, generating the corresponding target image. Based on this, utilizing only a single camera sensor and through a rationally designed optical path, different image acquisition functions can be cleverly implemented, simplifying the hardware design and meeting the requirements for lightweight glasses. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] 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 drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] FIG1 is a schematic structural diagram of a first image acquisition system provided by an embodiment of the present invention;

[0034] FIG2 is a schematic structural diagram of a second image acquisition system provided by an embodiment of the present invention;

[0035] FIG3 is a schematic structural diagram of a third image acquisition system provided by an embodiment of the present invention;

[0036] FIG4 is a flow chart of an image acquisition method of an image acquisition system provided by an embodiment of the present invention;

[0037] FIG5 is a partial schematic diagram of near-eye display glasses provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0039] The embodiments of the present application provide an image acquisition system and its image acquisition method and near-eye display glasses, which solve the technical problem of needing to set up multiple camera sensors, resulting in bloated glasses and increased design costs. It simplifies the hardware design and meets the requirements of lightweight glasses, as well as the requirements of beautiful and simple design.

[0040] The technical solution in the embodiments of the present application is to solve the above technical problems, and the overall idea is as follows:

[0041] In some possible scenarios, for example, eye image acquisition for fatigue assessment or iris ID recognition, or eye tracking via light spot reflection positioning, crystal laser scanning (i.e., capturing the location of pupil black spots), or retinal physiological feature imaging, the image acquisition technologies used in near-eye display glasses all require capturing the first imaging light from the eye side. The eye side refers to the side of the geometric light guide lens closest to the user's eye.

[0042] In other possible scenarios, for example, SLAM (Simultaneous Localization and Mapping) gesture interaction functions implemented by capturing gesture images, or RGB image acquisition functions developed to meet daily photography needs, the image acquisition technology used in near-eye display glasses requires the acquisition of a second imaging light source originating from the non-eye side. The non-eye side refers to the side of the geometric light guide lens away from the user's eyes.

[0043] Therefore, designing a single camera to achieve the different image acquisition functions of near-eye display glasses is of great significance. Accordingly, the image acquisition system provided by the embodiments of the present invention is based on a geometric light waveguide lens and includes a first coupling input optical element, a second coupling input optical element, a coupling output optical element, and a camera sensor.

[0044] During use, the first coupling-in optical element reflects the first imaging light originating from the eye side; the second coupling-in optical element transmits the first imaging light or reflects the second imaging light originating from the non-eye side; and the coupling-out optical element reflects the first imaging light or the second imaging light. This allows the different imaging light rays to be transmitted along corresponding optical paths to the camera sensor, generating the corresponding target image.

[0045] Based on this, by using only a single camera sensor and designing a reasonable optical path, different image acquisition functions can be cleverly achieved, simplifying the hardware design and meeting the lightweight requirements of glasses.

[0046] In particular, the provided image acquisition system can be applied to, but not limited to, near-eye display glasses such as VR / AR. The camera sensor can be located at the edge of the near-eye display glasses' frame, moving the camera sensor out of the eye's field of view. This concealed design meets the aesthetic and minimalist design requirements of the glasses.

[0047] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0048] Example 1:

[0049] As shown in FIG1 , an embodiment of the present invention provides an image acquisition system based on a geometric light waveguide lens, comprising a first coupling input optical element, a second coupling input optical element, a coupling output optical element, and a camera sensor.

[0050] The first coupling-in optical element, the second coupling-in optical element, and the coupling-out optical element are all embedded in the geometric light waveguide lens, and the second coupling-in optical element is located between the first coupling-in optical element and the coupling-out optical element.

[0051] The camera sensor faces the geometric light waveguide lens and is close to the coupling output optical element;

[0052] The incident area of ​​the first imaging light originating from the eye side on the geometric light waveguide lens, the first coupling-input optical element, the second coupling-input optical element, the coupling-out optical element and the camera sensor constitute a first optical path;

[0053] The incident area of ​​the second imaging light originating from the non-eye side on the geometrical light waveguide lens, the second coupling-in optical element, the coupling-out optical element and the camera sensor constitute a second optical path.

[0054] Specifically:

[0055] When it is necessary to collect the first imaging light originating from the eye side, the first optical path corresponding to the first optical path indicated by the solid arrow in FIG1 is:

[0056] First, the first imaging light is reflected by the first coupling input optical element to the second coupling input optical element; second, the first imaging light is transmitted by the second coupling input optical element to the coupling output optical element; third, the first imaging light is reflected by the coupling output optical element to the camera sensor; finally, the camera sensor collects the first imaging light to generate a corresponding target image.

[0057] When it is necessary to collect the second imaging light originating from the non-eye side, the second optical path corresponding to the second optical path shown by the dotted arrow in Figure 1 is:

[0058] First, the second imaging light is reflected by the second coupling input optical element to the coupling output optical element; secondly, the second imaging light is reflected by the coupling output optical element to the camera sensor; finally, the camera sensor collects the second imaging light to generate a corresponding target image.

[0059] As can be seen, the two partially overlapping optical paths in Figure 1 do not interfere with each other, and both can form independent images. Based on this, the embodiment of the present invention utilizes only a single camera sensor, cleverly implementing different image acquisition functions by designing the first and second optical paths, simplifying the hardware design and meeting the requirements for lightweight glasses.

[0060] In an optional embodiment, the first coupling input optical element is a first transflective coating; the first transflective coating is a first freeform surface with an opening facing the eye. This increases the field of view within the limited volume of the geometric light guide lens, thereby expanding the field of view of the camera sensor when capturing the first imaging light.

[0061] In an optional embodiment, the second coupling input optical element is a second semi-transparent and semi-reflective coating. Since the transmittance and reflectance of the second semi-transparent and semi-reflective coating are each 50%, it can simultaneously transmit the first imaging light and reflect the second imaging light.

[0062] The second transflective coating is a second free-form surface with its opening facing the non-eye side. This increases the field of view within the limited volume of the geometric light waveguide lens, thereby expanding the field of view of the camera sensor when collecting the second imaging light.

[0063] In an optional embodiment, the coupling-out optical element is a total reflection coating.

[0064] Since the coupling output optical element is close to the camera sensor, it can be considered that there is no need to increase the field of view angle in theory. Therefore, the total reflection coating can directly be a flat coating.

[0065] Furthermore, it is understood that:

[0066] First, the embodiments of the present invention do not limit the relative positions of the aforementioned input coupling optical element, second input coupling optical element, output coupling optical element, camera sensor, and geometric light guide lens. Rather, it should be understood that all possible relative positional relationships that meet the aforementioned functional requirements fall within the scope of protection claimed by the embodiments of the present invention.

[0067] For example, vertically flipping FIG1 as a whole to obtain the image acquisition system shown in FIG2 is one of the reasonable variations of the embodiment of the present invention.

[0068] For another example, horizontally flipping the coupling output optical element and the camera sensor in FIG. 1 to obtain the image acquisition system shown in FIG. 3 is also a reasonable variation of the embodiment of the present invention.

[0069] Second, for the different image acquisition functions of near-eye display glasses, the corresponding camera sensor selection criteria are usually inconsistent. In this regard, those skilled in the art should know that the embodiments of the present invention require the selection of a camera sensor type that can take into account all image acquisition functions.

[0070] For example, the image acquisition system provided is specifically used to simultaneously realize the eye tracking function by positioning the infrared spot reflected by the cornea, the SLAM gesture interaction function by capturing gesture images, and the RGB image acquisition function developed to meet daily photo or photography needs.

[0071] The eye tracking function requires a camera sensor with an operating wavelength of 850nm and 160,000 pixels; the SLAM gesture interaction function requires a camera sensor with an operating wavelength of 850nm and at least 3 million pixels; and the RGB image acquisition function requires a camera sensor with an operating wavelength of 380nm to 780nm (visible light), with the pixel count determined by the application. Therefore, it is necessary to consider all three requirements and select the appropriate camera sensor type (in fact, existing sensor technologies can also meet all of these parameters).

[0072] Example 2:

[0073] As shown in FIG4 , an embodiment of the present invention provides an image acquisition method of the image acquisition system as described in Example 1, including:

[0074] reflecting the first imaging light originating from the eye side by the first coupling-in optical element and transmitting the first imaging light along the first optical path to the second coupling-in optical element;

[0075] The first imaging light is transmitted through the second coupling-in optical element and transmitted to the coupling-out optical element along the first optical path; or the second imaging light originating from the non-eye side is reflected through the second coupling-in optical element and transmitted to the coupling-out optical element along the second optical path;

[0076] Reflecting the first imaging light or the second imaging light through the coupling output optical element, and transmitting the light to the camera sensor along the first optical path or the second optical path accordingly;

[0077] After the camera sensor collects the first imaging light or the second imaging light, it generates a corresponding target image.

[0078] Example 3:

[0079] An embodiment of the present invention provides near-eye display glasses, including the image acquisition system described in Example 1.

[0080] In an alternative embodiment, as shown in Figure 5, the camera sensor can be designed to be located at the edge of the frame of the near-eye display glasses. By moving the camera sensor out of the eye's visual area, the hidden design meets the design requirements of the glasses for aesthetics and simplicity.

[0081] It is not difficult to understand that since Examples 2 to 3 all include the image acquisition system in Example 1, the explanations, examples and beneficial effects of the relevant contents can refer to the corresponding parts in the image acquisition system and will not be repeated here.

[0082] In summary, compared with the existing technology, the present invention has the following beneficial effects:

[0083] 1. An embodiment of the present invention is based on a geometric light waveguide lens and includes a first coupling input optical element, a second coupling input optical element, a coupling output optical element, and a camera sensor. During use, the first coupling input optical element reflects the first imaging light originating from the eye side; the second coupling input optical element transmits the first imaging light or reflects the second imaging light originating from the non-eye side; and the coupling output optical element reflects the first imaging light or the second imaging light. This enables the different imaging light rays to be transmitted along corresponding optical paths to the camera sensor, generating the corresponding target image. Based on this, by utilizing only a single camera sensor and through a rationally designed optical path, different image acquisition functions can be cleverly implemented, simplifying the hardware design and meeting the requirements for lightweight glasses.

[0084] 2. The image acquisition system provided by the embodiments of the present invention can be applied to, but not limited to, near-eye display glasses such as VR / AR. The camera sensor can be located at the edge of the near-eye display glasses' frame, moving the camera sensor out of the eye's field of view. This concealed design meets the aesthetic and minimalist design requirements of the glasses.

[0085] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," 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 includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0086] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An image acquisition system based on a geometric light waveguide lens, comprising a first coupling input optical element, a second coupling input optical element, a coupling output optical element and a camera sensor; The first coupling-in optical element, the second coupling-in optical element, and the coupling-out optical element are all embedded in the geometric light waveguide lens, and the second coupling-in optical element is located between the first coupling-in optical element and the coupling-out optical element; The camera sensor faces the geometric light waveguide lens and is close to the coupling output optical element; in, The incident area of ​​the first imaging light from the eye side on the geometrical light waveguide lens, and the first coupling-in optical element, the second coupling-in optical element, the coupling-out optical element and the camera sensor constitute a first optical path; The incident area of ​​the second imaging light from the non-eye side on the geometrical light waveguide lens, the second coupling-in optical element, the coupling-out optical element and the camera sensor constitute a second optical path.

2. The image acquisition system according to claim 1, wherein: The first coupling input optical element is a first semi-transmissive and semi-reflective coating.

3. The image acquisition system according to claim 2, wherein: The first semi-transmissive and semi-reflective coating is a first free-curved surface, and the opening direction faces the eye side.

4. The image acquisition system according to claim 1, wherein: The second coupling input optical element is a second semi-transmissive and semi-reflective coating.

5. The image acquisition system according to claim 4, wherein: The second semi-transmissive and semi-reflective coating is a second free-curved surface, and the opening direction faces the non-eye side.

6. The image acquisition system according to claim 1, wherein: The coupling output optical element is a total reflection coating.

7. The image acquisition system according to claim 6, wherein: The total reflection coating is a planar coating.

8. An image acquisition method of the image acquisition system according to any one of claims 1 to 7, comprising: The first imaging light originating from the eye side is reflected by the first coupling-in optical element and transmitted to the second coupling-in optical element along the first optical path; The first imaging light is transmitted through the second coupling-in optical element and is transmitted along the first optical path to the coupling-out optical element; or reflecting the second imaging light originating from the non-eye side through the second coupling-in optical element and transmitting the second imaging light along the second optical path to the coupling-out optical element; Reflecting the first imaging light or the second imaging light through the coupling output optical element, and transmitting the light to the camera sensor along the first optical path or the second optical path accordingly; After the camera sensor collects the first imaging light or the second imaging light, it generates a corresponding target image.

9. A near-eye display glasses, comprising the image acquisition system according to any one of claims 1 to 7.

10. The near-eye display glasses according to claim 9, wherein: The camera sensor is located at the edge of the frame of the near-eye display glasses.

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