Three-axial dual-channel fisheye lens

Abstract

The application provides a three-optical-axis double-channel fisheye lens, including an optical technical feature scheme and an optical structural feature scheme of the three-optical-axis double-channel fisheye lens, and through the optical structure of the three-optical-axis double-channel fisheye lens, a mapping relationship that one object field corresponds to two image fields can be realized. The three-optical-axis fisheye lens is applied in a single-position dome projection system, can efficiently utilize pixels, and improves light energy utilization.

Description

Technical Field

[0001] This invention relates to the field of fisheye lens technology, and particularly to a three-optical-axis dual-channel fisheye lens. It pertains to the application of object-image asimilarity geometric optical imaging technology in specialized imaging engineering. Background Technology

[0002] Dome movies, also known as dome projection systems, are a type of special film that is loved by a wide audience for their novel form, stunning effects, and strong sense of presence and immersion.

[0003] With advancements in optical technology, film production technology, screen manufacturing technology, and digital image processing technology, as well as the maturity of graphics production and fusion splicing technology, dome projection systems have developed rapidly. In order to improve the brightness and clarity of images on the dome, dual and multi-camera configurations have emerged. However, the basic configuration of a single camera still occupies an important position due to its simple structure, low cost, and stable operation.

[0004] In a single-projector dome projection system, a fisheye lens is an indispensable component. A fisheye lens is a special type of lens that achieves a large field of view by sacrificing the similarity between the object and the image. Currently, traditional fisheye lenses all have a single optical axis optical structure. When projecting image information from the projector's image chip onto the dome, traditional fisheye lenses cannot establish a complete or efficient object-image mapping relationship between the dome and the image chip. This limitation in mapping results in low pixel utilization and light energy utilization. Summary of the Invention

[0005] In view of this, the present invention aims to propose a three-axis dual-channel fisheye lens to improve pixel and light energy utilization in single-camera dome projection systems.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0007] A three-axis dual-channel fisheye lens, the optical structure of which includes a front lens group, a rear upper lens group, and a rear lower lens group, has a principal optical axis and a first and a second secondary optical axis arranged parallel to each other in the same plane. The principal optical axis is the optical axis of the front lens group, the first secondary optical axis is the optical axis of the rear upper lens group, and the second secondary optical axis is the optical axis of the rear lower lens group, and the two secondary optical axes are symmetrically arranged with respect to the principal optical axis. The front lens group and the rear upper lens group form a first optical path channel, and the front lens group and the rear lower lens group form a second optical path channel. The optical structures of the rear upper lens group and the rear lower lens group are completely identical, thus the optical structures of the two optical path channels are completely identical. This three-axis dual-channel fisheye lens has the following technical features and regular optical structure features, wherein:

[0008] Technical features refer to the characteristics of the optical technical specifications of this three-axis dual-channel fisheye lens. These optical technical specifications mainly include: imaging formula, image height, field of view, and focal length.

[0009] The optical structural features refer to the characteristics of the optical structural parameters of the three-axis dual-channel fisheye lens. The main optical structural parameters involved include optical axis offset, optical power, number and type of lenses, channel aperture stop, and lens aperture stop.

[0010] The imaging relationship in the three-axis dual-channel fisheye lens technology features are as follows: the imaging relationship of the two optical paths is the same, and both adopt dissimilar imaging relationship, that is, the formed image has large distortion. The imaging relationship adopts any one of the commonly used "equidistant solid angle projection", "volume projection", "orthogonal projection", "equidistant projection" and "improved equidistant projection" in fisheye lens optical technology.

[0011] The field of view of the three-axis dual-channel fisheye lens is characterized by the following: the field of view of the lens is the field of view of any optical path channel, the maximum value of the field of view of the two optical path channels is the same, and the maximum value of the field of view is determined by the actual needs of the projection project.

[0012] The image height in the technical specifications of the three-axis dual-channel fisheye lens is characterized as follows: Image height refers to the image height of any optical path channel. When the field of view is at its maximum, the image heights of the two optical path channels are the same, and it is represented by the variable symbol y. The image height y is limited by the size of the matching projector image chip. To avoid ambiguity of negative values, only the absolute value of the image height |y| is discussed. The maximum value of |y| is determined by the length dimension a and the width dimension b of the image chip of the projector. If the length and width dimensions of the image chip are a≤2b, then the maximum value of |y| is |y|≈a / 4-δ, 0.1≤δ≤1, where δ is the reserved margin. If the length and width dimensions of the image chip are a≥2b, then the maximum value of |y| is: |y|≈b / 2.

[0013] The focal length in the technical specifications of the three-axis dual-channel fisheye lens is characterized as follows: the focal length of the lens refers to the focal length of any optical path channel. The focal lengths of the two optical path channels are the same, and are represented by the variable symbol f′. f′ is calculated and determined under the constraints of the imaging relation formula based on the known maximum field of view and image height value. For ease of explanation, the “improved equidistant projection” formula is selected as the imaging relation formula for further explanation. The imaging relation formula is as follows:

[0014] y = -kf′(ωπ / 180), 0.5 <k<1

[0015] Where ω is the field of view of the optical path channel, which is determined by the actual needs of the projection project; y is the image height corresponding to the field of view ω of the optical path channel; f′ is the focal length of the optical path channel; k is the distortion adjustment coefficient, which is used to adjust and balance the distortion; and π is pi. Once the imaging formula and the maximum value of the field of view are determined, f′ is uniquely determined by the image height y. The value of f′ exists in a range: |f′|=180y / kωπ, 0.5≤k≤1.

[0016] The optical axis offset in the regular optical structure features of the three-axis dual-channel fisheye lens refers to the vertical distance between the main optical axis and one of the secondary optical axes, denoted by the variable symbol E. E is determined by the chip length dimension a and width dimension b of the projector used. If described by the absolute value of the maximum image height of the optical path channel, then the range of values ​​for the optical axis offset satisfies the following formula:

[0017] The range of values ​​for the optical axis offset E is: |y|-2≤E≤|y|+2;

[0018] The optical power characteristic of the regular optical structure of the triaxial dual-channel fisheye lens is as follows: the optical power of the front lens group... A negative value indicates the optical power of the upper rear lens group. A positive value indicates the optical power of the rear lower lens group. The values ​​are positive, and the relationship between these optical powers satisfies the following equation:

[0019] Optical power relationship formula:

[0020] The characteristics of the channel aperture stops and lens aperture stops in the regular optical structure features of the three-axis dual-channel fisheye lens are as follows: the shape of each channel aperture stop of the three-axis dual-channel fisheye lens is no longer a conventional circle, but a semi-circle or semi-ellipse. The area of ​​the channel aperture stops is controlled to be half of the rated light-passing area of ​​the projector's output light path. The lens aperture stop of the three-axis dual-channel fisheye lens is composed of the channel aperture stops of the first optical path channel and the channel aperture stops of the second optical path channel.

[0021] The characteristic of the number of lenses in the regular optical structure of the three-axis dual-channel fisheye lens is as follows: the number of spherical lenses contained in the optical structure of the three-axis fisheye lens varies depending on the application requirements. The number of lenses in the front lens group is 5 to 12, the number of lenses in the upper rear lens group is 5 to 12, and the number of lenses in the lower rear lens group is 5 to 12.

[0022] The characteristic of the lens types in the regular optical structure of the three-axis dual-channel fisheye lens is that all lenses in the optical structure of the three-axis dual-channel fisheye lens are spherical lenses.

[0023] Furthermore, an optical filter or optical polarizer can be installed at the rear end of the three-axis dual-channel fisheye lens to project stereoscopic images onto a curved screen.

[0024] Furthermore, the front lens group, the upper rear lens group, and the lower rear lens group also include aspherical lenses, or plane mirrors and prisms; aspherical lenses can reduce the number of spherical lenses in the optical structure; prisms and plane mirrors can change the direction of the lens light path, causing the lens light path to deflect.

[0025] Furthermore, if the focal length of the lens is solved using the "equiangular projection", "stereoscopic projection", or "orthographic projection" formulas in the fisheye lens optical theory system, the other technical and optical structural features of the fisheye lens remain unchanged.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] The three-axis fisheye lens of the present invention forms a first optical path channel and a second optical path channel by the cooperation of the front group structure and the rear group structure of the lens. It can create a special mapping relationship between one "object" and two "images". The sum of the areas enclosed by the two image domains obtained on the image side of the lens is as close as possible to the effective area of ​​the image chip of the projector used, which greatly improves the pixel utilization rate and can also improve the light energy utilization rate.

[0028] Furthermore, the projection of stereoscopic images can be achieved by using optical filters or optical polarizers mounted on the lens, thus expanding the lens's range of applications.

[0029] Furthermore, through simple compatibility extensions, the fisheye lens of the present invention can be applied to the field of photography, and the technical specification processing method and optical structure construction process of the fisheye lens used for photography are almost completely consistent with the present invention. Attached Figure Description

[0030] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0031] Figure 1 This is a schematic diagram of the structure of the three-axis fisheye lens according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the image domain of the three-optical-axis dual-channel fisheye lens on the chip according to an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the image domain of a conventional fisheye lens on a chip according to an embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of the single-camera dome projection system according to an embodiment of the present invention;

[0035] Explanation of reference numerals in the attached figures:

[0036] 1. Lens aperture stop; 2. Front housing; 3. Front lens group; 4. Rear upper housing; 5. Rear lower housing; 6. Rear upper lens group; 7. Rear lower lens group; 8. Principal optical axis; 9. First secondary optical axis; 10. Second secondary optical axis.

[0037] S, image domain. Detailed Implementation

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0039] In the description of this invention, it should be noted that the terms "upper," "lower," "front," "rear," "inner," and "back," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] Furthermore, the optical structure of the lens mentioned in the embodiments of the present invention refers to the optical path composition that realizes the optical performance of the lens, including the lens in the optical path, the lens group formed by bonding two or more lenses together by a bonding process, the aperture stop, the optical axis and the air gap; wherein the lens is made of optical glass or optical plastic, the aperture stop is a light-passing hole made of metal for limiting the light flux, and the optical axis is the common reference axis of the lens, the lens group and the aperture stop in the optical path, which is a straight line in space.

[0041] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0042] Example

[0043] This embodiment relates to a three-axis dual-channel fisheye lens, which can improve pixel and light energy utilization in a single-camera dome projection system.

[0044] In terms of overall structure, combined Figure 1As shown, the lens group of this three-optical-axis dual-channel fisheye lens includes a front lens group 3, a rear upper lens group 6, and a rear lower lens group 7. This three-optical-axis dual-channel fisheye lens has a principal optical axis 8 and a first secondary optical axis 9 and a second secondary optical axis 10 arranged in parallel in the same plane. The principal optical axis 8 is the optical axis of the front lens group 3, the first secondary optical axis 9 is the optical axis of the rear upper lens group 6, and the second secondary optical axis 10 is the optical axis of the rear lower lens group 7. The two secondary optical axes are symmetrically arranged with respect to the principal optical axis 8. The front lens group 3 and the rear upper lens group 6 form the first optical path channel, and the front lens group 3 and the rear lower lens group 7 form the second optical path channel. The optical structures of the rear upper lens group 6 and the rear lower lens group 7 are completely identical, so the optical structures of the two optical path channels are completely identical.

[0045] Specifically, in combination Figure 1 As shown, the three-axis dual-channel fisheye lens of this embodiment includes a front lens group structure, a lens aperture stop 1, and a rear lens group structure. The front lens group structure includes a front housing 2 and a front lens group 3 disposed within the front housing 2. The rear lens group structure includes a rear upper housing 4 and a rear lower housing 5 symmetrically arranged perpendicular to the principal optical axis. The rear upper housing 4 is provided with a rear upper lens group 6, and the rear lower housing 5 is provided with a rear lower lens group 7. Both the rear upper housing 4 and the rear lower housing 5 are connected to the front housing 2.

[0046] Among them, the front lens group 3 and the rear upper lens group 6 form the first optical path channel, and the front lens group 3 and the rear lower lens group 7 form the second optical path channel. Both the first and second optical path channels pass through the aperture stop 1. The optical structures of the rear upper lens group 6 and the rear lower lens group 7 are completely identical, so the optical structures of the two optical path channels are completely identical.

[0047] At this point, as set up above, this embodiment uses the cooperation between the front lens group structure and the rear lens group structure to form a first optical path channel and a second optical path channel, which can create a special mapping relationship between one "object" and two "images," such as... Figure 2 As shown, the image domains S of the two "images" obtained on the lens image side do not overlap, and the sum of the areas enclosed by the two image domains S is as close as possible to the effective area of ​​the projector image chip, which greatly improves the pixel utilization rate and can also improve the light energy utilization rate.

[0048] It should be added that, such as Figure 3As shown, a traditional fisheye lens has only one optical axis, which can only create a mapping relationship between one "object" and one "image". The image field S generated by the lens image side is only one, and the utilization rate of the projector chip is low. However, in the three-optical-axis dual-channel fisheye lens of this embodiment, the two optical path channels have the same image plane position. For the same "object" height, the image heights of the two "images" formed by the two optical path channels are equal. The image field areas of the two image sides S formed by the two optical path channels on the image plane are the same. Both image fields are enclosed within the effective area of ​​the matched projector image chip, and the area enclosed by the two image fields is the largest.

[0049] Preferably, in this embodiment, the front lens group 3 has a principal optical axis 8, the rear upper lens group 6 has a first secondary optical axis 9, and the rear lower lens group 7 has a second secondary optical axis 10. The first secondary optical axis 9 and the second secondary optical axis 10 are symmetrically arranged along the principal optical axis 8, and the first secondary optical axis 9 is parallel to the second secondary optical axis 10. This makes the mechanical structure of the lens compact and simple, reduces the number of lenses required for refraction, and compresses the space required for the rear lens structure, thereby reducing the space occupied by the lens and facilitating the lightweighting of the device.

[0050] In addition, this tri-axis dual-channel fisheye lens has the following technical features and regular optical structural features, among which:

[0051] Technical characteristics refer to the optical technical specifications of this three-axis dual-channel fisheye lens. These optical technical specifications mainly include: imaging formula, image height, field of view, and focal length.

[0052] The optical structural features refer to the characteristics of the optical structural parameters of the three-axis dual-channel fisheye lens. The main optical structural parameters involved include optical axis offset, optical power, number and type of lenses, channel aperture stop, and lens aperture stop 1.

[0053] The imaging relationship in the three-axis dual-channel fisheye lens technology is characterized by the following: the imaging relationship of the two optical paths is the same, and both adopt dissimilar imaging relationships, that is, the formed image has a large value distortion. The imaging relationship adopts any one of the commonly used fisheye lens optical technologies, such as "equiangular projection", "stereoscopic projection", "orthogonal projection", "equidistant projection" and "improved equidistant projection".

[0054] The field of view of a three-axis dual-channel fisheye lens is characterized by the following: the field of view of the lens is the field of view of any one of the optical paths, the field of view of the two optical paths is the same, and the maximum value of the field of view is determined by the actual needs of the projection project.

[0055] In the technical specifications of a three-axis dual-channel fisheye lens, the image height is characterized as follows: Image height refers to the image height of any optical path channel. When the field of view is at its maximum, the image heights of the two optical path channels are the same, and it is represented by the variable symbol y. The image height y is limited by the size of the matching projector image chip. To avoid ambiguity due to negative values, only the absolute value of the image height, |y|, is discussed. The maximum value of |y| is determined by the length dimension a and the width dimension b of the image chip of the projector. If the length and width dimensions of the image chip are a≤2b, then the maximum value of |y| is |y|≈a / 4-δ, 0.1≤δ≤1, where δ is the reserved margin. If the length and width dimensions of the image chip are a≥2b, then the maximum value of |y| is: |y|≈b / 2.

[0056] The focal length in the technical specifications of a three-axis dual-channel fisheye lens is characterized as follows: the focal length of the lens refers to the focal length of any optical path channel. The focal lengths of the two optical path channels are the same, and are represented by the variable symbol f′. f′ is calculated and determined under the constraints of the imaging relation formula based on the known maximum field of view and image height value. For ease of explanation, the “improved equidistant projection” formula is selected as the imaging relation formula for further explanation. The imaging relation formula is as follows:

[0057] y = -kf′(ωπ / 180), 0.5 <k<1

[0058] Where ω is the field of view of the optical path channel, determined by the actual needs of the projection project; y is the image height corresponding to the field of view angle ω; f′ is the focal length of the optical path channel; k is the distortion adjustment coefficient, used to adjust and balance the distortion; and π is pi. Once the imaging formula and the field of view are determined, f′ is uniquely determined by the image height y, and the value of f′ exists within a range:

[0059] |f′|=180y / kωπ, 0.5≤k≤1.

[0060] In the regular optical structure features of a three-axis dual-channel fisheye lens, the optical axis offset refers to the vertical distance between the main optical axis 8 and one of the secondary optical axes, denoted by the variable symbol E. E is determined by the chip length dimension a and width dimension b of the projector used. If described by the absolute value of the maximum image height of the optical path channel, then the range of values ​​for the optical axis offset satisfies the following formula:

[0061] The range of optical axis offset E is: |y|-2≤E≤|y|+2.

[0062] The optical power characteristic of a three-axis dual-channel fisheye lens is as follows: the optical power of the front lens group 3... The value is negative, indicating the optical power of the rear upper lens group 6. The optical power of the rear lower lens group 7 is a positive value. The values ​​are positive, and the relationship between these optical powers satisfies the following equation:

[0063] Optical power relational expression:

[0064] Among the regular optical structural features of the three-optical-axis dual-channel fisheye lens, the features of the channel aperture stop and the lens aperture stop 1 are as follows: the shape of each channel aperture stop of the three-optical-axis dual-channel fisheye lens is no longer a conventional circle, but a semicircle or a semi-ellipse; the area of the channel aperture stop is controlled to be half of the rated light-passing area of the exit optical path of the projector, and the lens aperture stop 1 of the three-optical-axis dual-channel fisheye lens is jointly formed by the channel aperture stop of the first optical path channel and the channel aperture stop of the second optical path channel.

[0065] According to the regular equivalent principle optical structural feature of the three-optical-axis dual-channel, the number of spherical lenses contained in the optical structure of the three-optical-axis fisheye lens varies for different application requirements. In this embodiment, the number of lenses in the front lens group 3, the rear upper lens group 6 and the rear lower lens group 7 is 5 to 12. Under the application background of different dome projection projects, there will be different on-screen resolution requirements and field-of-view angle requirements, and digital projectors with different performances will also be used. Under different conditions and application environments, the structural complexity of this embodiment will be different, and the number of lenses contained therein will also be different. The present invention can select the appropriate number of lenses according to the adapted projector and screen requirements, which will neither increase the volume of the lens due to excessive lenses, but also ensure the basic use effect thereof.

[0066] Specifically, as Figure 4 shown, a single-position dome projection system is taken as an example for illustration in this embodiment. Assuming that the dome is a part of a standard spherical surface, and the maximum opening angle formed by the opening end face of the dome relative to the sphere center is 160°, and the fisheye lens is located at the sphere center of the dome, then the maximum field-of-view angle ω of the projection lens is 80°. A 4K-resolution digital projector is used as the projector in the system, and the size of the image chip of the projector is a 1.38-inch DMD, and the length a and width b of this image chip are about 31.0 mm and 16.3 mm respectively.

[0067] It can be known that a ≤ 2b, then the image heights of the first optical path channel and the second optical path channel shall follow |y|≈a / 4-δ. If δ=0.5 is taken, the absolute value of image height |y| corresponding to the maximum field-of-view angle of the first optical path channel and the second optical path channel is 7.25 mm, and 0.5<k<1 (different values only affect the distortion of the optical channel, and do not affect the definition of the system). After calculation, 5.2 ≤ f' ≤ 10.4 can be obtained, that is, the focal length value range of the first optical path channel and the second optical path channel is obtained, and if there is no other restriction, a value within this range is sufficient.

[0068] The value range of the optical axis offset E of the lens can be obtained through calculation as follows: 5.25 ≤ E ≤ 9.25.

[0069] according to By implementing optical power allocation, the lens group is selected, and the front and rear group structures of the lens are established.

[0070] Based on the above principles for processing optical technical indicators, a suitable initial structure can be established, and a three-axis dual-channel fisheye lens that meets the requirements can be obtained through commonly used aberration processing and optimization techniques.

[0071] Preferably, in this embodiment, the three-axis dual-channel fisheye lens can have an optical filter or optical polarizer installed or matched at its rear end. Using optical filters or polarizers with different performance can ensure that an image containing parallax is projected onto the curved screen in order to produce a stereoscopic image effect.

[0072] It should be noted that when projecting 3D images, viewers need to wear glasses made with matching optical filters or polarizing filters to observe the 3D images on the dome screen.

[0073] Furthermore, as a preferred embodiment, aspherical lenses, or plane mirrors and prisms can be added to the front lens group 3, the rear upper lens group 6, and the rear lower lens group 7 in this embodiment. By adding aspherical lenses, the number of spherical lenses in the optical structure can be reduced. By adding prisms and plane mirrors, the direction of the lens optical path can be changed, causing the lens optical path to deflect.

[0074] Furthermore, as a preferred embodiment, if the imaging relationship of this embodiment is solved by using the "equiangular projection", "stereoscopic projection" and "orthogonal projection" formulas in the optical theory system of fisheye lenses, while keeping the characteristics of other technical indicators and the regular optical structure characteristics of fisheye lenses unchanged, a similar fisheye lens can also be designed.

[0075] Furthermore, as a preferred embodiment, this embodiment is only discussed in the field of dome projection engineering. However, this embodiment is also applicable to the field of photography. With simple matching extensions, it can be applied to the field of photography. The technical specification processing method and the construction process of the regular optical structure of the fisheye lens used for photography are almost completely the same as those in this invention.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A three-optical-axis dual-channel fisheye lens, characterized in that, The lens group of this three-axis dual-channel fisheye lens includes a front lens group (3), a rear upper lens group (6), and a rear lower lens group (7). This three-axis dual-channel fisheye lens has a main optical axis (8) and a first secondary optical axis (9) and a second secondary optical axis (10) arranged in parallel in the same plane. The main optical axis (8) is the optical axis of the front lens group (3), the first secondary optical axis (9) is the optical axis of the rear upper lens group (6), and the second secondary optical axis (10) is the optical axis of the rear lower lens group (7). The two secondary optical axes are arranged symmetrically with respect to the main optical axis (8). The front lens group (3) and the rear upper lens group (6) constitute the first optical path channel, and the front lens group (3) and the rear lower lens group (7) constitute the second optical path channel. The optical structures of the rear upper lens group (6) and the rear lower lens group (7) are completely identical, so the optical structures of the two optical path channels are completely identical. This three-axis dual-channel fisheye lens has the following technical features and regular optical structure features, wherein: Technical features refer to the characteristics of the optical technical specifications of this three-axis dual-channel fisheye lens. These optical technical specifications mainly include: imaging formula, image height, field of view, and focal length. The optical structure features refer to the characteristics of the optical structure parameters of the three-axis dual-channel fisheye lens. The main optical structure parameters involved include optical axis offset, optical power, number and type of lenses, channel aperture stop and lens aperture stop (1). The imaging relationship in the three-axis dual-channel fisheye lens technology features are as follows: the imaging relationship of the two optical paths is the same, and both adopt dissimilar imaging relationship, that is, the formed image has large distortion. The imaging relationship adopts any one of the "equidistant solid angle projection", "volume projection", "orthogonal projection", "equidistant projection" and "improved equidistant projection" commonly used in fisheye lens optical technology. The field of view feature of the three-axis dual-channel fisheye lens technology is as follows: the field of view of the lens is the field of view of any optical path channel, the field of view of the two optical path channels is the same, and the maximum value of the field of view is determined by the actual needs of the projection project. The image height feature of the described three-axis dual-channel fisheye lens technology is as follows: Image height refers to the image height of any optical path channel. When the corresponding field of view is at its maximum value, the image heights of the two optical path channels are the same. The image height is determined by the variable sign. To refer to, like Gao Due to the size limitations of the matching projector image chip, to avoid ambiguity regarding negative values, only the absolute value of the image height is discussed. , The maximum value is determined by the length dimension 'a' and width dimension 'b' of the image chip used in the projector. If the length and width dimensions of the image chip are related as follows: ,but The maximum value is , , As a margin, if the length and width dimensions of the image chip are as follows: ,but The maximum value is: ; The focal length feature of the described three-axis dual-channel fisheye lens technology is as follows: the focal length of the lens refers to the focal length of any one optical path channel; the focal length values ​​of the two optical path channels are the same, and are represented by variable symbols. To refer to, It is calculated and determined based on the known field of view and image height values ​​under the constraints of the imaging relation. For ease of explanation, the "improved equidistant projection" formula is selected as the imaging relation for further explanation. The imaging relation is as follows: ， ； in, The field of view of the optical path is determined by the actual needs of the projection project. field of view of the optical path channel The corresponding image height, The focal length of the optical path channel. It is the distortion adjustment coefficient, used to adjust and balance the distortion. Pi; once the imaging formula and the field of view are determined... The only one made by high Decide, The value of exists within a range: ； The optical axis offset in the optical structure of the three-axis dual-channel fisheye lens is characterized by the following: the optical axis offset refers to the vertical distance between the principal optical axis (8) and one of the secondary optical axes, determined by the variable symbol. To refer to, Determined by the chip length dimension 'a' and width dimension 'b' of the projector used, if described by the absolute value of the maximum image height of the optical path channel, then the range of values ​​for the optical axis offset satisfies the following formula: Optical axis offset The range of values ​​for: ; The optical power characteristic of the three-axis dual-channel fisheye lens is as follows: the optical power of the front lens group (3) The optical power of the upper rear lens group (6) is negative. For a positive value, the optical power of the rear lower lens group is (7). The values ​​are positive, and the relationship between these optical powers satisfies the following equation: Optical power relationship formula: ; The characteristics of the channel aperture stop and lens aperture stop (1) in the optical structure features of the three-axis dual-channel fisheye lens are as follows: the shape of each channel aperture stop of the three-axis dual-channel fisheye lens is no longer a conventional circle, but a semi-circle or semi-ellipse. The area of ​​the channel aperture stop is controlled to be half of the rated light-passing area of ​​the projector's output light path. The lens aperture stop (1) of the three-axis dual-channel fisheye lens is composed of the channel aperture stop of the first optical path channel and the channel aperture stop of the second optical path channel. The characteristic of the number of lenses in the optical structure of the three-axis dual-channel fisheye lens is as follows: the number of spherical lenses contained in the three-axis fisheye lens optical structure varies depending on the application requirements. The number of lenses in the front lens group (3) is 5 to 12, the number of lenses in the upper rear lens group (6) is 5 to 12, and the number of lenses in the lower rear lens group (7) is 5 to 12.

2. The three-optical-axis dual-channel fisheye lens according to claim 1, characterized in that: It also includes optical filters or optical polarizers installed at the rear end of the lens. Using optical filters or optical polarizers with different properties, stereoscopic images can be projected onto a curved screen.

3. The three-optical-axis dual-channel fisheye lens according to claim 2, characterized in that: The front lens group (3), the upper rear lens group (6) and the lower rear lens group (7) also include aspherical lenses, or plane mirrors and prisms; The number of spherical lenses in an optical structure can be reduced by using aspherical lenses. By using prisms and plane mirrors, the direction of the lens's light path can be changed, causing the light path to deflect.

4. The tri-optical-axis dual-channel fisheye lens according to any one of claims 1-3, characterized in that: If the imaging relationship is solved using the "equiangular projection", "stereoscopic projection" and "orthogonal projection" formulas in the fisheye lens optical theory system, the focal length of the fisheye lens remains unchanged, while other technical features and regular optical structural features remain unchanged.

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