A blind area-free panoramic annular stereoscopic imaging lens

Abstract

The application discloses a non-blind area panoramic annular stereoscopic imaging lens, which comprises lenses L1, a panoramic annular lens L2 and a rear lens group G3 arranged in sequence along an optical path direction and arranged along an optical axis; the L2 comprises a front transmission surface R3 and a front reflection surface R4 on a subject side; and the L2 comprises a central transmission surface R5 and a polarization light splitting half-reflection half-transmission surface R6 on an image side; the L1, the L2 and the G3 form three channels; a field of view range of a front channel is 0~alpha, and light rays pass through the L1, the R3, the R5 and the G3 in sequence to reach an image plane; a field of view range of a panoramic channel is alpha~beta, and light rays pass through the R3, the R6, the R4, the R5 and the G3 in sequence to reach the image plane; a field of view range of a stereoscopic imaging channel is gamma~theta, and 0<gamma<theta<beta, light rays pass through the R3, the R6 and the G3 in sequence to reach the image plane to form a stereoscopic vision image. The application has no central blind area, has a large stereoscopic imaging field of view, can realize single-lens stereoscopic imaging in a visible light range and has a simple head structure.

Description

Technical Field

[0001] This invention relates to the field of stereo imaging, and more particularly to a panoramic ring-shaped stereo imaging lens with no blind spots. Background Technology

[0002] In recent years, with the development of network transmission technology and artificial intelligence, traditional imaging systems have been unable to meet the requirements of fields such as machine vision, intelligent recognition, and autonomous driving. Panoramic ring lenses, as a special type of ultra-wide-angle optical system, can capture ambient light around the system in a 360° radius, obtaining a wide range of information. Especially in the field of multi-dimensional information perception, panoramic ring lenses can capture a large amount of depth image information of objects within a panoramic field of view. However, traditional panoramic ring systems suffer from drawbacks such as a central blind zone, a large system head, a large overall system length, difficulty in miniaturization, and high manufacturing costs.

[0003] Traditional single-lens panoramic stereo imaging systems have two-channel structures: one consisting of a reflector and a fisheye lens mounted coaxially; another consisting of a reflector and a panoramic ring lens mounted coaxially; and yet another consisting of two panoramic ring lenses mounted coaxially. All of these can acquire panoramic stereo vision information with high imaging quality. However, they have drawbacks such as the inability to acquire forward field of view information, a central blind zone in the detector, complex structure, and high difficulty in manufacturing and assembly. In addition, they are relatively large in size, making them difficult to miniaturize and unsuitable for applications in confined spaces and small robot scenarios. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a blind-spot-free panoramic ring-shaped stereo imaging lens.

[0005] The specific technical solution is as follows:

[0006] A blind-spot-free panoramic ring-shaped stereo imaging lens includes a lens L1, a panoramic ring-shaped lens L2, and a rear lens group G3 arranged sequentially along the optical path direction and on the optical axis; the object-side side of L2 includes a front transmission surface R3 and a front reflection surface R4; the image-side side includes a circular transmission surface R5 located at the center and an annular polarizing beam splitting semi-reflective and semi-transparent surface R6 located around R5.

[0007] L1, L2, and G3 constitute three channels: a front channel, a panoramic channel, and a stereo imaging channel. The field of view of the front channel is 0 to α, and light rays pass through L1, R3, R5, and G3 in sequence to reach the image plane and form an image. The field of view of the panoramic channel is α to β, and light rays pass through R3 for transmission, R6 for reflection, R4 for reflection, R5 for transmission, and G3 in sequence to reach the image plane and form a ring image. The field of view of the stereo imaging channel is γ to θ, and 0 < γ < θ < β, and light rays pass through R3 for transmission, R6 for transmission, and G3 in sequence to reach the image plane and form a stereoscopic image.

[0008] Furthermore, the object-side surface of the lens L1 is the transmission surface R1, which is convex, and the image-side surface is the transmission surface R2, which is concave.

[0009] Furthermore, the rear lens group G3 consists of four lenses: a first lens L3, a second lens L4, a third lens L5, and a fourth lens L6, arranged sequentially along the optical axis in the optical path direction. The object-side surface of the first lens L3 is a transmission surface R7, which is flat, and the image-side surface is a transmission surface R8, which is concave. The object-side surface of the second lens L4 is a transmission surface R9, and the image-side surface is a transmission surface R10, both of which are concave. The third lens L6... Lens 5 is a cemented doublet. Its object-side surface is the transmitting surface R11, its middle surface is the cemented surface R12, and its image-side surface is the transmitting surface R13. R11 is a convex surface, R12 convexes towards the object side, and R13 is a concave surface. Lens 6 is a cemented doublet. Its object-side surface is the transmitting surface R14, its middle surface is the cemented surface R15, and its image-side surface is the transmitting surface R16. R14 is a convex surface, R15 convexes towards the image side, and R16 is a concave surface.

[0010] Furthermore, R6 is obtained by depositing a polarizing thin film on the lens, which exhibits transmission or reflection effects depending on the incident angle of the light.

[0011] Furthermore, it also includes an aperture stop, which is disposed at the transmission surface R11.

[0012] Furthermore, the field of view of the front channel is 0° to 40°, the field of view of the panoramic channel is 40° to 105°, and the field of view of the stereo imaging channel is 20° to 50°.

[0013] Furthermore, the optical system parameters for each surface are shown in the table below.

[0014]

[0015] Among them, the object side of lens L1 is the transmission surface R1, which is convex, and the image side is the transmission surface R2, which is concave.

[0016] The beneficial effects of this invention are:

[0017] The panoramic ring-shaped stereo imaging lens of the present invention has no blind spot, no central blind spot, a large stereo imaging field of view, and can realize single-lens stereo imaging in the visible light range. The head structure is simple. Attached Figure Description

[0018] Figure 1 This is a structural diagram of the panoramic ring-shaped stereo imaging lens with no blind spots according to the present invention.

[0019] Figure 2 This is a structural diagram of the front channel of the panoramic ring-shaped stereoscopic imaging lens of the present invention, which has no blind spots.

[0020] Figure 3 This is a diagram of the panoramic channel structure of the panoramic ring-shaped stereoscopic imaging lens of the present invention, which has no blind spots.

[0021] Figure 4 This is a structural diagram of the stereoscopic imaging channel of the panoramic ring-shaped stereoscopic imaging lens without blind spots in this invention. Detailed Implementation

[0022] The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. The objectives and effects of the present invention will become clearer as a result. The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] like Figure 1 As shown, the blind-spot-free panoramic ring-shaped stereo imaging lens includes a front lens group G1, a panoramic ring-shaped lens group G2, and a rear lens group G3 arranged sequentially along the optical path direction and on the optical axis.

[0024] The front lens group G1 consists of a lens L1. The object-side surface of lens L1 is the transmission surface R1, which is convex, and the image-side surface is the transmission surface R2, which is concave.

[0025] The panoramic ring lens group G2 consists of a panoramic ring lens L2. The panoramic ring lens L2 includes two reflective surfaces and two transmissive surfaces. The object-side surface includes a front transmissive surface R3 and a ring-shaped front reflective surface R4. The ring-shaped portion of R3 is located on the periphery of R4, and the circular area in the center of R4 is also a transmissive surface, i.e., the circular portion of R3. The image-side surface includes a centrally located circular transmissive surface R5 and a ring-shaped polarizing transmissive surface R6 located around the periphery of R5. The transmissive surface R6 is obtained by coating a polarizing film onto a regular lens, exhibiting either transmission or reflection depending on the angle of incidence of light.

[0026] The rear lens group G3 consists of four lenses, namely the first lens L3, the second lens L4, the third lens L5, and the fourth lens L6, arranged in sequence along the optical axis in the direction of the optical path. Among them, the first lens L3 has a transmitting surface R7 on the object side, which is flat, and a transmitting surface R8 on the image side, which is concave; the second lens L4 has a transmitting surface R9 on the object side and a transmitting surface R10 on the image side, both of which are concave; the third lens L5 is a cemented doublet lens, with a transmitting surface R11 on the object side, a cemented surface R12 on the middle side, and a transmitting surface R13 on the image side, where R11 is convex, R12 convex towards the object side, and R13 is concave; the fourth lens L6 is a cemented doublet lens, with a transmitting surface R14 on the object side, a cemented surface R15 on the middle side, and a transmitting surface R16 on the image side, where R14 is convex, R15 convex towards the image side, and R16 is concave. Whether the cemented surfaces R12 and R15 need to protrude, and specifically whether they face the object or image side, as well as the lens assembly of the entire rear lens group G3, can all be adjusted according to actual design requirements.

[0027] The system aperture can be set on the front or rear surface of any lens in the rear lens group G3. In this embodiment, the system aperture is set on the front surface R11 of the third lens L5 to eliminate stray light introduced by the polarizing beam splitting film coated on the rear surface R6 of the panoramic ring lens, thereby improving the imaging quality and making the image clearer.

[0028] Existing single-lens panoramic ring-shaped stereo imaging lenses generally consist of a front reflecting mirror and a panoramic ring-shaped lens, or two panoramic ring-shaped lenses with the same optical axis. However, the front reflecting mirror and the front panoramic ring-shaped lens are usually large in size and have complex surface shapes, making them difficult to manufacture and costly. Furthermore, the large front lens group has high requirements for stability and assembly. In order to simplify the structure and reduce costs, this invention uses a single lens L1 as the front lens group G1 and utilizes a panoramic ring-shaped lens with a semi-reflective and semi-transparent surface R6 that has a ring-polarized beam splitting structure to achieve stereo vision imaging.

[0029] The blind-spot-free panoramic ring stereo imaging lens designed in this invention has three channels: a front channel, a panoramic channel, and a stereo imaging channel.

[0030] like Figure 2 As shown, ray 1 is the center field-of-view ray of the front channel, with an angle of 0° to the optical axis; ray 2 is the edge field-of-view ray of the front channel, with an angle of α to the optical axis; the field of view of the front channel is 0 to α; in this embodiment, α = 40°. Ray 1 or ray 2 passes sequentially through the front lens group G1, the panoramic ring lens group G2 (passing through R3 and R5), and the rear lens group G3 to reach the image plane, forming an image.

[0031] like Figure 3As shown, ray 3 is the minimum field-of-view ray of the panoramic channel, with an angle α between it and the optical axis; ray 4 is the maximum field-of-view ray of the panoramic channel, with an angle β between it and the optical axis; the field-of-view range of the panoramic channel is α~β; in this embodiment, β=105°. Ray 3 or ray 4 is transmitted sequentially through the front transmission surface R3 of the panoramic ring lens L2, reflected by the rear surface semi-reflective and semi-transparent surface R6, reflected by the front surface reflective surface R4, transmitted through the rear surface circular transmission surface R5, and finally reaches the image plane through the rear lens group G3, forming a ring image.

[0032] like Figure 4 As shown, ray 5 is the minimum field-of-view ray of the stereo imaging channel, with an angle γ to the optical axis; ray 6 is the maximum field-of-view ray of the stereo imaging channel, with an angle θ to the optical axis; the field of view of the stereo imaging channel is γ to θ, and 0 < γ < θ < β, that is, the range of γ to θ is within 0 to β; in this embodiment, γ = 20°, θ = 50°, and the field of view of the stereo imaging channel is 20° to 50°. Ray 5 or ray 6 is transmitted sequentially through the front transmissive surface R3 of the panoramic ring lens L2, through the rear semi-reflective and semi-transparent surface R6, and through the rear mirror group G3 to reach the image plane, combining with the panoramic channel to form a stereoscopic visual image.

[0033] In this embodiment, the focal length of the front channel is 0.284 mm, F = 4.707; the focal length of the panoramic channel is 0.269 mm, F = 4.688; and the focal length of the stereo imaging channel is 1.474 mm, F = 4.705. The optical system parameters of each surface are shown in Table 1, with the surfaces arranged in the order of ray tracing. All surfaces are standard spherical surfaces made of conventional glass, simplifying the lens structure and reducing manufacturing costs. The lens designed in this invention is suitable for detectors with a pixel size of 3.4 μm and operating in the visible light band.

[0034] Table 1 Optical System Parameters

[0035]

[0036] It will be understood by those skilled in the art that the above descriptions are merely preferred examples of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A panoramic circumferential stereo imaging lens with no blind spots, characterized in that, The system includes a lens L1, a panoramic ring lens L2, and a rear lens group G3 arranged sequentially along the optical axis in the direction of the optical path. The object-side surface of the panoramic ring lens L2 includes a front transmissive surface R3 and a ring-shaped front reflective surface R4. The ring-shaped portion of the front transmissive surface R3 is located around the front reflective surface R4, and the circular area in the middle of the front reflective surface R4 is the transmissive surface. The image-side surface includes a circular transmissive surface R5 located at the center and a ring-shaped polarizing and semi-transmissive surface R6 located around the outer periphery of the circular transmissive surface R5. The semi-transmissive surface R6 exhibits either transmission or reflection depending on the angle of incidence of the light. The lens L1, panoramic ring lens L2, and rear lens group G3 constitute three channels: a front channel, a panoramic channel, and a stereo imaging channel. The field of view of the front channel is 0~α. Light passes through lens L1, front transmission surface R3, circular transmission surface R5, and rear lens group G3 in sequence to reach the image plane, forming an image. The field of view of the panoramic channel is α~β. Light passes through front transmission surface R3 for transmission, semi-reflective surface R6 for reflection, front reflection surface R4 for reflection, circular transmission surface R5 for transmission, and rear lens group G3 in sequence to reach the image plane, forming a ring image. The field of view of the stereo imaging channel is γ~θ, and 0<γ<θ<β. Light passes through front transmission surface R3 for transmission, semi-reflective surface R6 for transmission, and rear lens group G3 in sequence to reach the image plane, forming a stereoscopic image. The object-side surface of the lens L1 is the transmission surface R1, and the image-side surface is the transmission surface R2. The rear lens group G3 consists of four lenses arranged sequentially along the optical axis: a first lens L3, a second lens L4, a third lens L5, and a fourth lens L6. The object-side surface of the first lens L3 is a transmissive surface R7, and the image-side surface is a transmissive surface R8. The object-side surface of the second lens L4 is a transmissive surface R9, and the image-side surface is a transmissive surface R10. The object-side surface of the third lens L5 is a transmissive surface R11, the middle surface is a cemented surface R12, and the image-side surface is a transmissive surface R13. The object-side surface of the fourth lens L6 is a transmissive surface R14, the middle surface is a cemented surface R15, and the image-side surface is a transmissive surface R16. The optical system parameters for each surface are shown in the table below: 。 2. The blind-spot-free panoramic ring-shaped stereo imaging lens according to claim 1, characterized in that, The semi-reflective and semi-transparent surface R6 is obtained by depositing a polarizing thin film on the lens.

3. The blind-spot-free panoramic ring-shaped stereo imaging lens according to claim 1, characterized in that, The field of view of the front channel is 0° to 40°, the field of view of the panoramic channel is 40° to 105°, and the field of view of the stereo imaging channel is 20° to 50°.

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