Thin pancake lens-based 360-degree visual angle lens assembly and shooting device

Abstract

The invention relates to the technical field of machine vision lenses, and discloses a pancake lens-based 360-degree visual angle lens assembly and a shooting device. The 360-degree visual angle lens assembly comprises a pancake lens group and an imaging lens which are sequentially arranged from an object side to an image side. An entrance pupil center point P1 of the pancake lens group is positioned in front of the 360-degree visual angle lens assembly and is positioned on one side, far away from the pancake lens group, of the object; light emitted from an object is refracted and reflected by the pancake lens group and is converged to a central position P2 of an entrance pupil of the imaging lens; the position of P2 and the position of P1 are conjugated with each other with respect to the pancake lens group. Through the design of the folding light path, the total length of the optical module is greatly reduced, the optical module has the advantages of being light, thin, low in weight and the like, the whole side face of an object can be completely shot by 360 degrees only by being matched with one camera, and the detection cost and difficulty can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of machine vision lenses, and in particular to a 360-degree viewing angle lens assembly and a shooting device based on a pancake lens. Background Art

[0002] In many machine vision applications, it is often necessary to capture a complete view of the surface of an object. For example, different types of bottles and containers, as well as cylindrical parts such as screws, nuts, and shafts, need to be inspected for scratches and impurities on their sides, or barcodes need to be read, etc.; because many of the features to be inspected are located on the side of the object rather than the top, and conventional machine vision lenses can only capture one side of the object at a time, in order to obtain the complete surface information of the object, it is necessary to place multiple cameras around and above the object for shooting. In addition to increasing the system cost, there are also functional issues with electronic equipment or software management.

[0003] A lens with a 360-degree viewing angle only needs one camera to capture the entire side of an object in 360 degrees. There are already some technical solutions on the market that can achieve 360-degree viewing angle detection, but the optical paths of these solutions are relatively long, making the shooting equipment too large and bloated, and the scope of application is relatively narrow.

[0004] How to reduce the size of the optical module as much as possible to make it lighter, thinner and more compact while realizing a 360-degree viewing angle detection solution has become a technical problem that needs to be urgently solved by technicians in this field.

[0005] The above information is presented as background information only to assist with understanding the present disclosure and no determination or admission is made as to whether any of the above may be used as prior art with respect to the present disclosure. Summary of the invention

[0006] The object of the present invention is to provide a 360-degree viewing angle lens assembly and a shooting device based on a pancake lens, so as to solve or at least partially solve the technical problems existing in the prior art.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a 360-degree viewing angle lens assembly based on a pancake lens, characterized in that it comprises a pancake lens group and an imaging lens arranged in sequence from the object side to the image side;

[0009] The center point P1 of the incident pupil of the pancake lens group is located in front of the 360-degree viewing angle lens assembly and on the side of the object away from the pancake lens group; the light emitted from the object is refracted and reflected by the pancake lens group and converges to the center position P2 of the incident pupil of the imaging lens; the position of P2 is conjugate with the position of P1 with respect to the pancake lens group.

[0010] Optionally, the pancake lens group consists of a single pancake lens;

[0011] The light emitted from the object is refracted by the first surface of the pancake lens, reflected by the second surface of the pancake lens, reflected by the first surface of the pancake lens, and refracted by the second surface of the pancake lens in sequence, and then refocused by the imaging lens to form an image.

[0012] Optionally, a light-splitting film is coated on the first surface of the pancake lens and the second surface of the pancake lens.

[0013] Optionally, the pancake lens assembly consists of a double-cemented pancake lens;

[0014] The light emitted from the object is sequentially refracted by the first surface of the double-cemented pancake lens, refracted by the cemented surface of the double-cemented pancake lens, reflected by the third surface of the double-cemented pancake lens, refracted by the cemented surface of the double-cemented pancake lens, reflected by the first surface of the double-cemented pancake lens, refracted by the cemented surface of the double-cemented pancake lens and refracted by the third surface of the double-cemented pancake lens, and then the imaging lens refocuses the light to form an image.

[0015] Optionally, a beam splitting film is coated on the first surface of the double-cemented pancake lens and the third surface of the double-cemented pancake lens.

[0016] Optionally, the pancake lens group consists of a first lens and a second lens, and both the first lens and the second lens are pancake lenses;

[0017] The light emitted from the object is refracted by the first surface of the first lens, refracted by the second surface of the first lens, reflected by the first surface of the second lens, refracted by the second surface of the first lens, reflected by the first surface of the first lens, refracted by the second surface of the first lens, refracted by the first surface of the second lens, refracted by the second surface of the second lens, and then refocused by the imaging lens to form an image.

[0018] Optionally, a beam splitting film is coated on the first surface of the first lens and the first surface of the second lens.

[0019] Optionally, the optical axis of the pancake lens group coincides with the optical axis of the imaging lens.

[0020] In a second aspect, the present invention provides a photographing device, including a camera and a lens assembly, wherein the lens assembly adopts a 360-degree viewing angle lens assembly based on a pancake lens as described above.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The 360-degree viewing angle lens assembly provided by the present invention can shorten the total length of the optical module through the design of folded light path, and has the advantages of being light, thin and low in weight. Moreover, only one camera is needed to fully capture the entire side of an object in 360 degrees, thereby reducing the cost and difficulty of detection.

[0023] The present invention has other features and advantages, which will be apparent from or will be described in detail in the accompanying drawings and the following detailed description incorporated herein, which together serve to explain the specific principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0025] Figure 1 The figure is a schematic diagram of the optical path structure of a 360-degree viewing angle lens assembly based on a pancake lens provided in an embodiment of the present invention.

[0026] Figure 2 It is a schematic diagram of the optical path structure of another 360-degree viewing angle lens assembly based on a pancake lens provided in an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the optical path structure of another 360-degree viewing angle lens assembly based on a pancake lens provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to explain in detail the possible application scenarios, technical principles, specific schemes that can be implemented, and the purposes and effects that can be achieved, the following is a detailed description of the specific embodiments listed in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0029] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0030] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0031] In the description of this application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that three relationships may exist, for example, A and / or B, which means: A exists, B exists, and A and B exist at the same time. In addition, the character " / " in this article generally indicates that the objects before and after are in an "or" logical relationship.

[0032] In the present application, terms such as “first” and “second” are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship of quantity, priority or sequence between these entities or operations.

[0033] Without further limitations, in this application, the words "include", "comprises", "has" or other similar expressions used in the sentences are intended to cover non-exclusive inclusion. These expressions do not exclude the presence of additional elements in the process, method or product including the elements, so that the process, method or product including a series of elements may include not only those limited elements, but also other elements not explicitly listed, or also include elements inherent to such process, method or product.

[0034] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than", "less than", "exceed" and the like are understood to exclude the number itself; expressions such as "above", "below", "within" and the like are understood to include the number itself. In addition, in the description of the embodiments of this application, "multiple" means more than two (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups", "multiple times", etc., unless otherwise clearly and specifically limited.

[0035] In the description of the embodiments of the present application, space-related expressions used, such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "vertical", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or position relationship based on the orientation or position relationship shown in the specific embodiments or drawings, and are only for the convenience of describing the specific embodiments of the present application or facilitating the reader's understanding, and do not indicate or imply that the referred device or component must have a specific position, a specific orientation, or be constructed or operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0036] Unless otherwise expressly specified or limited, in the description of the embodiments of the present application, the terms such as "install", "connect", "connect", "fix", "set", etc. used should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integrated setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For technicians in the technical field to which the present application belongs, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0037] Embodiment 1:

[0038] See also Figure 1 , Figure 2 or Figure 3 , Figure 1 1 is a schematic diagram of the optical path structure of a 360-degree viewing angle lens assembly based on a pancake lens provided by an embodiment of the present invention. Figure 2 is a schematic diagram of the optical path structure of another 360-degree viewing angle lens assembly based on a pancake lens provided by an embodiment of the present invention, Figure 3 This is a schematic diagram of the optical path structure of another 360-degree viewing angle lens assembly based on a pancake lens provided by an embodiment of the present invention;

[0039] This embodiment provides a 360-degree viewing angle lens assembly based on a pancake lens, comprising a pancake lens group 100 and an imaging lens 200 arranged in sequence from the object side to the image side; wherein the imaging lens 200 is used to refocus light to form an image of an object;

[0040] The incident pupil center point P1 of the pancake lens assembly 100 is located in front of the 360-degree viewing angle lens assembly and is located on the side of the object away from the pancake lens assembly 100; the light emitted from the object (such as Figure 1 As shown, the light emitted from the side and top of the object (the main light is equivalent to that emitted from P1) is refracted and reflected by the pancake lens group 100 and converges to the center position P2 of the incident light pupil of the imaging lens 200; the position of P2 is conjugate with the position of P1 with respect to the pancake lens group 100.

[0041] Since the entrance pupils of the pancake lens group 100 and the imaging lens 200 satisfy the imaging conjugate relationship, the 360-degree viewing angle lens assembly is like accepting only the light emitted from point P1. Lights with different NA values ​​correspond to the sides of the object at different positions, thereby achieving a complete 360-degree shooting of the entire side and even the top of the object.

[0042] Specifically, Figure 1As shown, as one embodiment, the pancake lens assembly 100 is composed of a single pancake lens 110;

[0043] The light emitted from the object is sequentially refracted by the first surface 111 of the pancake lens 110, reflected by the second surface 112 of the pancake lens 110, reflected by the first surface 111 of the pancake lens 110, and refracted by the second surface 112 of the pancake lens 110, and then refocused by the imaging lens 200 to form an image;

[0044] The first surface 111 of the pancake lens 110 and the second surface 112 of the pancake lens 110 are coated with a beam splitting film.

[0045] As another optional implementation, Figure 2 As shown, the pancake lens assembly 100 is composed of a double-cemented pancake lens 120;

[0046] The light emitted from the object is sequentially refracted by the first surface 121 of the double-cemented pancake lens 120, refracted by the cemented surface 122 of the double-cemented pancake lens 120, reflected by the third surface 123 of the double-cemented pancake lens 120, refracted by the cemented surface 122 of the double-cemented pancake lens 120, reflected by the first surface 121 of the double-cemented pancake lens 120, refracted by the cemented surface 122 of the double-cemented pancake lens 120, and refracted by the third surface 123 of the double-cemented pancake lens 120, and then refocused by the imaging lens 200 to form an image;

[0047] The first surface 121 of the double-cemented pancake lens 120 and the third surface 123 of the double-cemented pancake lens 120 are coated with a beam splitting film.

[0048] Compared with the previous embodiment, the double-cemented pancake lens 120 is beneficial for reducing chromatic aberration.

[0049] As another optional implementation, Figure 3 As shown, the pancake lens assembly 100 is composed of a first lens 130 and a second lens 140 , and both the first lens 130 and the second lens 140 are pancake lenses;

[0050] The light emitted from the object is sequentially refracted by the first surface 131 of the first lens 130, refracted by the second surface 132 of the first lens 130, reflected by the first surface 141 of the second lens 140, refracted by the second surface 132 of the first lens 130, reflected by the first surface 131 of the first lens 130, refracted by the second surface 132 of the first lens 130, refracted by the first surface 141 of the second lens 140, and refracted by the second surface 142 of the second lens 140, and then refocused by the imaging lens 200 to form an image;

[0051] The first surface 131 of the first lens 130 and the first surface 141 of the second lens 140 are coated with a beam splitting film.

[0052] Compared with the above embodiment, the two separated pancake lenses have greater degrees of freedom, can achieve a larger incident light angle, and can also better optimize aberrations to achieve better imaging effects.

[0053] In this embodiment, the optical axis of the pancake lens assembly 100 and the optical axis of the imaging lens 200 coincide with each other.

[0054] In summary, this embodiment combines the pancake lens-based optical solution with the visual detection technology, and effectively utilizes the advantages of the pancake lens optical solution, such as the ability to fold the light path to reduce the total length of the optical module, and the thinness and low weight, to realize a technical solution that can detect objects with a 360-degree viewing angle. It only needs one camera to fully capture the surface of the object, and there is no need to place multiple cameras around or above the object, thereby reducing shooting space and costs.

[0055] Embodiment 2:

[0056] This embodiment provides a shooting device, including a camera and a 360-degree viewing angle lens assembly based on a pancake lens;

[0057] Specifically, Figure 1 As shown, the 360-degree viewing angle lens assembly includes a pancake lens group 100 and an imaging lens 200 which are sequentially arranged from the object side to the image side;

[0058] The imaging lens 200 is used to refocus the light to form an image of the object;

[0059] The incident pupil center point P1 of the pancake lens assembly 100 is located in front of the 360-degree viewing angle lens assembly and is located on the side of the object away from the pancake lens assembly 100; the light emitted from the object (such as Figure 1 As shown, the light emitted from the side and top of the object (the main light is equivalent to that emitted from P1) is refracted and reflected by the pancake lens group 100 and converges to the center position P2 of the incident light pupil of the imaging lens 200; the position of P2 is conjugate with the position of P1 with respect to the pancake lens group 100.

[0060] Since the entrance pupils of the pancake lens group 100 and the imaging lens 200 satisfy the imaging conjugate relationship, the 360-degree viewing angle lens assembly is like accepting only the light emitted from point P1. Lights with different NA values ​​correspond to the sides of the object at different positions, thereby achieving a complete 360-degree shooting of the entire side and even the top of the object.

[0061] like Figure 1 As shown, as one implementation, the pancake lens assembly 100 may be composed of only a single pancake lens 110;

[0062] The light emitted from the object is sequentially refracted by the first surface 111 of the pancake lens 110, reflected by the second surface 112 of the pancake lens 110, reflected by the first surface 111 of the pancake lens 110, and refracted by the second surface 112 of the pancake lens 110, and then refocused by the imaging lens 200 to form an image;

[0063] The first surface 111 of the pancake lens 110 and the second surface 112 of the pancake lens 110 are coated with a beam splitting film.

[0064] As another optional implementation, Figure 2 As shown, the pancake lens assembly 100 may be a double cemented pancake lens 120;

[0065] The light emitted from the object is sequentially refracted by the first surface 121 of the double-cemented pancake lens 120, refracted by the cemented surface 122 of the double-cemented pancake lens 120, reflected by the third surface 123 of the double-cemented pancake lens 120, refracted by the cemented surface 122 of the double-cemented pancake lens 120, reflected by the first surface 121 of the double-cemented pancake lens 120, refracted by the cemented surface 122 of the double-cemented pancake lens 120, and refracted by the third surface 123 of the double-cemented pancake lens 120, and then refocused by the imaging lens 200 to form an image;

[0066] The first surface 121 of the double-cemented pancake lens 120 and the third surface 123 of the double-cemented pancake lens 120 are coated with a beam splitting film.

[0067] Compared with the previous embodiment, the double-cemented pancake lens 120 is beneficial for reducing chromatic aberration.

[0068] As another optional implementation, Figure 3 As shown, the pancake lens assembly 100 may also be composed of a first lens 130 and a second lens 140, and the first lens 130 and the second lens 140 are both pancake lenses;

[0069] The light emitted from the object is sequentially refracted by the first surface 131 of the first lens 130, refracted by the second surface 132 of the first lens 130, reflected by the first surface 141 of the second lens 140, refracted by the second surface 132 of the first lens 130, reflected by the first surface 131 of the first lens 130, refracted by the second surface 132 of the first lens 130, refracted by the first surface 141 of the second lens 140, and refracted by the second surface 142 of the second lens 140, and then refocused by the imaging lens 200 to form an image;

[0070] The first surface 131 of the first lens 130 and the first surface 141 of the second lens 140 are coated with a beam splitting film.

[0071] Compared with the above embodiment, the two separated pancake lenses have greater degrees of freedom, can achieve a larger incident light angle, and can also better optimize aberrations to achieve better imaging effects.

[0072] In this embodiment, the optical axis of the pancake lens assembly 100 and the optical axis of the imaging lens 200 coincide with each other.

[0073] Since the optical solution of the above-mentioned pancake lens can fold the light path to shorten the total length of the optical module, it can not only make the shooting device thinner and lighter, but also realize a technical solution that can detect the 360-degree viewing angle of the object. It only needs to be equipped with one camera to completely shoot the surface of the object, reducing shooting space and cost.

[0074] In summary, this embodiment proposes a shooting device, which can shorten the total length of the optical module by folding the light path through an optical solution based on a pancake lens. It has the advantages of being light, thin and low in weight. It can also be combined with visual detection technology. Only one camera is needed to capture the entire side of an object in 360 degrees, thereby reducing the detection cost and difficulty.

[0075] As described above, 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 the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. 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 embodiments of the present invention.

Claims

1. A 360-degree viewing angle lens assembly based on a pancake lens, characterized in that: It comprises a pancake lens group (100) and an imaging lens (200) which are arranged in sequence from the object side to the image side; The center point P1 of the incident pupil of the pancake lens group (100) is located in front of the 360-degree viewing angle lens assembly and on the side of the object away from the pancake lens group (100); light emitted from the object is refracted and reflected by the pancake lens group (100) and converges to the center position P2 of the incident pupil of the imaging lens (200); the position of P2 and the position of P1 are conjugate with each other with respect to the pancake lens group (100).

2. A 360-degree viewing angle lens assembly based on a pancake lens according to claim 1, characterized in that: The pancake lens assembly (100) consists of a single pancake lens (110); Light emitted from an object is sequentially refracted by the first surface (111) of the pancake lens (110), reflected by the second surface (112) of the pancake lens (110), reflected by the first surface (111) of the pancake lens (110), and refracted by the second surface (112) of the pancake lens (110), and then refocused by the imaging lens (200) to form an image.

3. The 360-degree viewing angle lens assembly based on a pancake lens according to claim 2, characterized in that: A light-splitting film is coated on the first surface (111) of the pancake lens (110) and the second surface (112) of the pancake lens (110).

4. The 360-degree viewing angle lens assembly based on a pancake lens according to claim 1, characterized in that: The pancake lens assembly (100) is composed of a double-cemented pancake lens (120); The light emitted from the object is sequentially refracted by the first surface (121) of the double-cemented pancake lens (120), refracted by the cemented surface (122) of the double-cemented pancake lens (120), reflected by the third surface (123) of the double-cemented pancake lens (120), refracted by the cemented surface (122) of the double-cemented pancake lens (120), reflected by the first surface (121) of the double-cemented pancake lens (120), refracted by the cemented surface (122) of the double-cemented pancake lens (120), and refracted by the third surface (123) of the double-cemented pancake lens (120), and then the imaging lens (200) refocuses the light to form an image.

5. The 360-degree viewing angle lens assembly based on a pancake lens according to claim 4, characterized in that: The first surface (121) of the double-glued pancake lens (120) and the third surface (123) of the double-glued pancake lens (120) are coated with a beam splitting film.

6. The 360-degree viewing angle lens assembly based on a pancake lens according to claim 1, characterized in that: The pancake lens assembly (100) consists of a first lens (130) and a second lens (140), wherein the first lens (130) and the second lens (140) are both pancake lenses; Light emitted from an object is sequentially refracted by a first surface (131) of a first lens (130), refracted by a second surface (132) of the first lens (130), reflected by a first surface (141) of a second lens (140), refracted by a second surface (132) of the first lens (130), reflected by a first surface (131) of the first lens (130), refracted by a second surface (132) of the first lens (130), refracted by a first surface (141) of a second lens (140), and refracted by a second surface (142) of the second lens (140), and then refocused by the imaging lens (200) to form an image.

7. The 360-degree viewing angle lens assembly based on a pancake lens according to claim 6, characterized in that: The first surface (131) of the first lens (130) and the first surface (141) of the second lens (140) are coated with a beam splitting film.

8. The 360-degree viewing angle lens assembly based on a pancake lens according to claim 1, characterized in that: The optical axis of the pancake lens group (100) and the optical axis of the imaging lens (200) both coincide with each other.

9. A photographing device, comprising a camera and a lens assembly, characterized in that: The lens assembly adopts a 360-degree viewing angle lens assembly based on a pancake lens as described in any one of claims 1-8.

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