Optical fiber image transmission unit

Abstract

The invention provides an optical fiber image transmitting unit. The optical fiber image transmitting unit comprises an optical fiber bundle with a plurality of image transmitting optical fibers and an isolating layer, and the optical fiber bundle forms an optical fiber receiving end facing an object side and an optical fiber emitting end facing an image side along an optical axis; the image transmitting optical fiber forms a receiving end surface for receiving an image at the optical fiber receiving end and forms an emergent end surface for outputting the image at the optical fiber emergent end; the ratio of the area of the receiving end face to the area of the emergent end face is 1: N, N is larger than 1, the area of the cross section, perpendicular to the optical axis, of the image transmitting optical fiber is evenly increased from the optical fiber receiving end to the optical fiber emergent end so that an amplified image can be output through the emergent end face, and the optical fiber receiving end completely covers emergent light converged by the imaging unit located on the object side. According to the optical detection device, long-distance transmission and image amplification of the image are realized through the optical fiber bundle, the technical problems of complex structure, low image transmission quality and poor image signal imaging quality of the optical detection device comprising the optical fiber image transmission unit are solved, and the imaging quality is finally ensured.

Description

[0001] Information about divisional applications

[0002] This application is a divisional application of the invention patent application with the application date of January 18, 2024, application number 202410074646.8, and invention name "Fiber optic image transmission unit, fiber optic imaging system and optical detection equipment". Technical Field

[0003] The present invention relates to the field of optical technology, and in particular to an optical fiber image transmission unit. Background Art

[0004] In a conventional endoscope imaging system, after the objective lens system images the object W, the clear image formed based on the object W needs to be amplified and transmitted to the back-end photoelectric conversion module for reception and conversion into an image signal. Optics usually need to introduce an optical system such as a relay lens system and a magnifying lens system between the objective lens system and the photoelectric conversion module. The relay lens system and the magnifying lens system are used in the endoscope imaging system to transmit and amplify the light obtained by the objective lens system.

[0005] In the image transmission structure of the prior art, it is usually necessary to use an optical system such as a relay lens system and a magnifying lens system to achieve Figure 1 The long-distance transmission and image magnification of the image formed by the measured object W are determined by the need for the endoscopic imaging system to be inserted into the tissue of a specific area of ​​the human body, especially for the detection scenes of smaller neuronal cells and gastrointestinal endoscopes that need to be inserted at a deeper depth. Since the relay mirror system and the magnifying glass system need to introduce multiple sets of concave lenses, convex lenses, or optical devices such as apertures, and thus cause the light to continuously penetrate the aforementioned optical devices. There are defects such as high light loss, installation eccentricity between lenses, optical distortion, etc., which leads to low image transmission quality and ultimately affects the imaging quality of the image signal.

[0006] In addition, the relay mirror system needs to be encapsulated in a slender sheath. If there is a slight deviation in the collimation of the sheath during processing, or if the sheath is slightly deformed due to force when the endoscope imaging system is in use, it will further aggravate the aforementioned technical problems. There are also multiple groups of concave lenses and convex lenses arranged in the sheath, which may be misaligned, deflected relative to the central optical axis, or even damaged due to uneven force.

[0007] Therefore, the optical systems in the prior art, especially the endoscopic imaging systems, have defects of complex optical device structures and low image transmission quality, which need to be solved urgently. Summary of the invention

[0008] The purpose of the present invention is to disclose an optical fiber image transmission unit for solving the aforementioned technical problems, and in particular to solve the technical problems in the prior art that optical devices such as concave lenses, convex lenses or apertures encapsulated by mirror sheaths have complex structures, low image transmission quality and poor image signal imaging quality.

[0009] The present invention provides an optical fiber image transmission unit, which is integrally packaged in a housing and includes:

[0010] An optical fiber bundle having a plurality of image transmission optical fibers and an isolation layer, wherein the optical fiber bundle forms an optical fiber receiving end facing the object side and an optical fiber emitting end facing the image side along the optical axis, and the plurality of image transmission optical fibers are closely arranged in the isolation layer, and the cross section of the image transmission optical fiber is one of a regular triangle, a regular quadrilateral, and a regular hexagon;

[0011] The image transmission optical fiber forms a receiving end face for receiving an image at the optical fiber receiving end, and forms an output end face for outputting an image at the optical fiber output end;

[0012] The ratio of the receiving end face area to the emitting end face area is 1:N, N is greater than 1, and the transverse cross-sectional area of ​​the image transmission optical fiber along the perpendicular direction to the optical axis increases uniformly from the optical fiber receiving end to the optical fiber emitting end, so as to output the amplified image through the emitting end face;

[0013] The optical fiber receiving end completely covers the outgoing light rays converged by the imaging unit located on the object side.

[0014] As a further improvement of the present invention, the optical fiber bundle is composed of a plurality of image transmission optical fibers having the same cross-sectional specifications and sizes along the optical axis and arranged in a cluster.

[0015] As a further improvement of the present invention, when N is equal to 4, the ratio of the side length of the image-transmitting optical fiber at the receiving end face to the side length at the output end face is 1:2, the ratio of the area of ​​the receiving end face to the area of ​​the output end face is 1:4, and the image received by the receiving end face is magnified four times and output through the output end face.

[0016] As a further improvement of the present invention, the optical fiber receiving end is provided with an anti-reflection optical film.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] In the present application, an optical fiber bundle is composed of multiple image transmission optical fibers arranged along the optical axis, and the transverse cross-sectional area of ​​the image transmission optical fibers along the transverse cross-sectional area perpendicular to the optical axis increases uniformly from the optical fiber receiving end to the optical fiber output end, so as to output the amplified image through the output end face, thereby realizing long-distance transmission and image amplification of the image through the optical fiber bundle, and solving the technical problems of complex structure, low image transmission quality and poor image signal imaging quality existing in optical detection equipment (for example, endoscope system) including optical fiber image transmission units, and improving the durability and reliability of optical fiber imaging systems including optical fiber image transmission units and optical detection equipment including optical fiber imaging systems, and ultimately ensuring the imaging quality and image display effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of the overall structure of the optical detection device of the present invention, and Figure 1 The optical fiber imaging system included in the optical detection equipment can be used Figure 4 The fiber optic imaging system 100a shown or Figure 5 The fiber optic imaging system 100b shown or Figure 6 Any of the fiber optic imaging systems 100c shown;

[0020] Figure 2 The optical fiber image transmission unit of the present invention and the outer ring illumination optical fiber assembly are provided along Figure 1 A cross-sectional view formed by the optical axis P;

[0021] Figure 3 For the direction perpendicular to Figure 1 A cross-sectional view formed by arbitrarily cutting the optical fiber image transmission unit and the outer ring illumination optical fiber group in the direction of the central optical axis P;

[0022] Figure 4 FIG. 1 is a schematic diagram of the overall structure of the optical fiber imaging system of the present invention in one embodiment, wherein: Figure 4 Omitted Figure 1 Objective lens system in

[0023] Figure 5 FIG. 1 is a schematic diagram of the overall structure of the optical fiber imaging system of the present invention in another embodiment, wherein: Figure 5 Omitted Figure 1 Objective lens system in

[0024] Figure 6 FIG. 1 is a schematic diagram of the overall structure of a fiber optic imaging system in another embodiment of the present invention, wherein: Figure 6 Omitted Figure 1 Objective lens system in

[0025] Figure 7 is a schematic diagram of a light focusing unit along the optical axis P in one embodiment;

[0026] Figure 8 is a schematic diagram of a light focusing unit along the optical axis P in a modified embodiment;

[0027] Fig. 9 For along Figure 8 The cross-sectional view formed by the DD focusing unit. DETAILED DESCRIPTION

[0028] The present invention is described in detail below in conjunction with the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these embodiments are all within the scope of protection of the present invention.

[0029] The optical fiber imaging unit 1 in each embodiment disclosed in the present application is a part of the optical fiber imaging system 100a (or the optical fiber imaging system 100b, or the optical fiber imaging system 100c), and the optical fiber imaging system is a part of the optical detection device 1000. The optical detection device 1000 can be understood as an endoscope imaging system. Therefore, the optical detection device 1000 is used at least to observe human tissues or human regions or in vitro biological tissues such as cranial brain tissue, nerve cells, gastrointestinal tract, and abdominal cavity. Figure 1 As shown, the direction where the measured object W is located is the object side, and the direction opposite to the measured object W is the image side. Figures 4 to 6 The left side is the object side, and the right side is the image side. The technical concept of the invention to be protected by the present application is exemplified below through a number of specific implementations, and the technical terms recorded in the embodiments are to be understood according to the common meanings in the technical field to which the present application belongs unless otherwise specified.

[0030] Ginseng Figures 1 to 3As shown, the present application first discloses a specific embodiment of an optical fiber image transmission unit 1. The optical fiber image transmission unit 1 comprises: an optical fiber bundle 10 having a plurality of image transmission optical fibers 11, wherein the optical fiber bundle 10 forms an optical fiber receiving end 101 facing the object side and an optical fiber output end 102 facing the image side along an optical axis P. The image transmission optical fiber 11 forms a receiving end face 111 for receiving an image at the optical fiber receiving end 101, and forms an output end face 112 for outputting an image at the optical fiber output end 102. The receiving end face 111 is composed of a plurality of optical fiber receiving ends 101, and the output end face 112 is composed of a plurality of optical fiber output ends 102. The area ratio of the receiving end face 111 to the exit end face 112 is 1:N, where N is greater than 1 (for example, N=1.1, N=1.5, N=2.3, N=3, etc.), and the cross-sectional area of ​​the image transmission optical fiber 11 along the transverse direction perpendicular to the optical axis P increases uniformly from the optical fiber receiving end 101 to the optical fiber exit end 102, so that the image transmission optical fiber 11 output through the exit end face 112 forms an enlarged image due to the linear increase in the cross-sectional area along the optical axis P. Optionally, the optical fiber bundle 10 in this embodiment can be composed of a plurality of image transmission optical fibers 11 having the same cross-sectional specifications and dimensions along the optical axis P arranged in a cluster. The image transmission optical fibers 11 arranged in a cluster can further simplify the assembly and debugging process. The optical fiber image transmission unit 1 is in the shape of a truncated cone. The area of ​​the aforementioned receiving end face 111 refers to the sum of the cross-sectional areas of all the imaging optical fibers 11 at the optical fiber receiving end 101 , and the area of ​​the aforementioned emitting end face 112 refers to the sum of the cross-sectional areas of all the imaging optical fibers 11 at the optical fiber emitting end 102 .

[0031] When N is equal to 4, the ratio of the side length of the image transmission optical fiber 11 at the receiving end face 111 to the side length at the exit end face 112 is 1:2, the ratio of the area of ​​the receiving end face 111 to the area of ​​the exit end face 112 is 1:4, and the image received by the receiving end face 111 is magnified four times and output through the exit end face 112. It is pointed out that the magnified four times output is that the original size of the image formed by the imaging unit 2 incident on the receiving end face 111 is completely magnified four times in the process of passing through the image transmission optical fiber 11 and reaching the exit end face 112, and the image magnified four times is formed at the exit end face 112 for output and is acquired by the image acquisition unit 5. The optical fiber image transmission unit 1 realizes both the long-distance transmission of the image and the reasonable magnification of the image, and thus the magnifying glass system included in the endoscope system in the prior art can be omitted, and the collimating system (i.e., rod mirror) configured in the endoscope system to ensure the long-distance transmission of the image can be replaced at the same time. Based on the image magnified four times in the optical fiber image transmission unit 1, it is finally further digitally magnified in the image acquisition unit 5, and a final magnification effect of one thousand times can be achieved. For the endoscope system (i.e., a subordinate concept of the optical detection device 1000) including the optical fiber image transmission unit 1, it is not advisable to set the magnification of the image transmitted between the receiving end face 111 and the output end face 112 too high, which is not only due to the objective limitation of the display size, but also based on the objective determination of the actual size of the object W to be measured. The cell body size of a neuron cell (excluding axons and dendrites) is usually around 5 to 100 microns. In order to meet the display needs of a small-sized display in an operating room environment, it is usually necessary to magnify the original image by about one thousand times, so that a certain number of cell nuclei can be observed in a narrow surgical field, and a certain number of neuronal cells can be displayed on the display after magnification, so as to determine whether the tissue in the target area of ​​the human body has lesions. If the original image is magnified too little, the design complexity of the peripheral circuits and the difficulty of developing the software algorithm included in the image acquisition unit 5 will be significantly increased; if the original image is magnified too much, the size of the output end face 112 formed by the optical fiber bundle 10 will be infinitely magnified, which is obviously not practical for the semiconductor process size of CMOS or CCD commonly used in the industry, because the maximum semiconductor process size of CMOS or CCD is 36mmx24mm. Therefore, the technical solution of magnifying the image received by the receiving end face 111 by four times and outputting it through the output end face 112 is a relatively ideal implementation method, and can meet the actual application scenarios of endoscope systems used in interventional surgery, for example.

[0032] The above-mentioned uniform increase can be understood as that all the image transmission optical fibers 11 from the optical fiber receiving end 101 to the optical fiber output end 102 along the optical axis P are closely arranged and there is no gap between each image transmission optical fiber 11 in the horizontal direction. Since the cross section of the image transmission optical fiber 11 is one of a regular triangle, a regular quadrilateral, and a regular hexagon, and the multiple image transmission optical fibers 11 constituting the optical fiber bundle 10 are bundled with each other, the cross-sectional shapes along the optical axis P are all of the same type and the cross-sectional shapes are kept consistent from the receiving end face 111 to the output end face 112. Each image transmission optical fiber 11 is configured to be sub-millimeter level, for example, 2 microns, 10 microns, 50 microns, 100 microns, etc., whether at the optical fiber receiving end 101 or at the optical fiber output end 102.

[0033] Therefore, no matter the image transmission optical fiber 11 with a regular triangle cross section or a regular hexagon cross section, the edges of the image transmission optical fiber 11 are all attached to each other and the image is completely spliced ​​to ensure that the image of the object W obtained by the self-imaging unit 2 can be completely transmitted to the optical fiber output end 102 at the rear end to be finally transmitted through Figure 1 The image acquisition unit 5 (for example, a CCD or CMOS sensor and its peripheral circuit) converts the optical signal into an electrical signal to be displayed on the screen. In view of the fact that the image acquisition unit 5 is not the invention point of the present application, and any CCD or CMOS sensor and its peripheral circuit in the prior art can be used, the description thereof is omitted in the embodiments of the present application. It can be seen from this that the applicant pointed out that the cross-sectional shape of the aforementioned image transmission optical fiber 11 is a regular triangle or a regular hexagon is only a typical example, and the cross-sectional shape of the image transmission optical fiber 11 can also include other shapes that meet the requirements that the edges formed by each image transmission optical fiber 11 can be completely bordered after being tightly fitted, and that there is no gap between the image transmission optical fibers 11 on any cross section formed along the optical axis P, and the cross-sectional area of ​​the image transmission optical fiber 11 increases linearly from the optical fiber receiving end 101 to the optical fiber emitting end 102 to achieve the invention purpose and technical effect of the present application.

[0034] At the same time, the above-mentioned uniform increase can also be understood as the cross-sectional area of ​​all image transmission optical fibers 11 from the optical fiber receiving end 101 to the optical fiber output end 102 along the optical axis P gradually increasing from the optical fiber receiving end 101 located at the front end to the optical fiber output end 102 located at the rear end in a continuous and smooth trend (i.e., linear increase). This gradual increase is the linear increase of the cross-sectional area of ​​a single image transmission optical fiber 11 from the object side to the image side along the optical axis P, and the linear increase of the total cross-sectional area of ​​all image transmission optical fibers 11 at any cross-sectional position along the optical axis P from the object side to the image side along the optical axis P. The bundled multiple image transmission optical fibers 11 transmit each image area of ​​the image formed by the imaging unit 2 from the optical fiber receiving end 101 to the optical fiber output end 102. Therefore, compared with the existing technology of realizing long-distance transmission and image magnification of images through a combination of lenses such as convex lenses and concave lenses, the fiber optic image transmission unit 1 in this embodiment can transmit each image area with the help of a single optical fiber (i.e., the image transmission optical fiber 11) with negligible light loss through each image transmission optical fiber 11, and form each amplified image area at the optical fiber output end 102, and finally splice to form the entire amplified image, which is captured by the image acquisition unit 5 and forms a digital signal image.

[0035] At the same time, the image transmission through the image transmission fiber 11 can ensure the quality of image transmission even in a curved observation scene and expand the scope of application. In actual scenes, the outer shell (not shown) that encapsulates the optical fiber image transmission unit 1 as a whole can also have a certain flexibility to meet the use requirements of bending and circuitous advancement under complex observation conditions inside the human body. At the same time, the image is transmitted through the image transmission fiber 11 and the image is amplified by the image transmission fiber 11 whose cross-sectional area increases linearly, so as to achieve high fidelity and high resolution of the image. Optionally, the optical fiber image transmission unit 1 can be encapsulated as a whole in a stainless steel thin shell (not shown). Even if the stainless steel thin shell is slightly bent during manufacturing or use, resulting in poor collimation, the image transmission fiber 11 has the characteristics of being bendable and transmitting images, thereby solving the technical problems of the lens being misaligned, deflected relative to the central optical axis, or even damaged when the lens is used to transmit and amplify the image in the prior art. Finally, since the image transmission fiber 11 is transparent, it can meet the transmission of images in the visible light range as well as the transmission of images in the ultraviolet range and the infrared range, and has a large scope of use.

[0036] An imaging unit 2 is arranged on the object side of the optical fiber image transmission unit 1; optionally, the imaging unit 2 may be composed of a biconvex lens, or may be composed of a plurality of lens groups (including concave lens, convex lens, aspherical lens, plano-concave lens, crescent lens, cemented achromatic lens, etc.) and formed on the object side along the optical axis P, and preferably is a biconvex lens. The optical fiber receiving end 101 can at least completely cover the range of incident light captured by the imaging unit 2 from the object side along the optical axis P, and the outgoing light 23 converged by the imaging unit 2 can be converged on the receiving end face 111 formed by the optical fiber receiving end 101, so that under the premise of ensuring the field of view formed by the imaging unit 2, the image of the object W to be measured formed by the imaging unit 2 is completely injected into the optical fiber bundle 10, and is transmitted from the front end to the rear end through the optical fiber bundle 10 over a long distance, and a digital image is formed and displayed through the image acquisition unit 5.

[0037] Ginseng Figure 3 As shown, in this embodiment, the optical fiber bundle 10 also includes: an isolation layer 12, and a plurality of image transmission optical fibers 11 are closely arranged in the isolation layer 12. The optical fiber receiving end 101 is provided with an anti-reflection optical film. The anti-reflection optical film is used to filter and increase the transmittance of light (including visible light, ultraviolet light or infrared light), thereby ensuring the image quality of the image emitted from the exit end face 112. The isolation layer 12 can be made of a rigid material (for example, stainless steel), or it can be a flexible braided layer made of a flexible material (for example, carbon fiber) and completely encloses all the image transmission optical fibers 11 along the optical axis P. Generally, the isolation layer 12 can have a certain light shielding property, and can also be completely light shielding. In this embodiment, the isolation layer 12 can also play the role of supporting the outer ring illumination optical fiber group 3 located on its outer side and wrapping the sealant 14 located on its inner side for fixing. After multiple image transmission optical fibers 11 are closely arranged to form the image transmission optical fiber 11, a sealant 14 can be filled between the image transmission optical fiber 11 and the isolation layer 12 to solidify the image transmission optical fiber 11, thereby preventing the image transmission optical fiber 11 from undergoing lateral displacement perpendicular to the optical axis P and longitudinal displacement along the optical axis P in the channel area enclosed by the isolation layer 12. At the same time, a circle of incident optical fibers 31 located outside the isolation layer 12 can also be solidified and fixed by the sealant 15. The outer ring illumination optical fiber group 3 composed of multiple incident optical fibers 31 is wrapped by an outer shell 16. Exemplarily, the outer shell 16 can also be made of the same material as the isolation layer 12. As an optional embodiment, a protective layer can be further wrapped on the outside of the outer shell 16, such as the aforementioned stainless steel thin shell, and the protective layer can surround and wrap the entirety along the optical axis P. Figure 1The imaging unit 2 and the optical fiber image transmission unit 1 and the objective lens system 6 located between the object W to be measured and the imaging unit 2, since the protective layer and the objective lens system 6 are not the inventive points of the invention referred to in this application, they are omitted in each embodiment of this application. The multiple incident optical fibers 31 included in the outer ring illumination optical fiber group 3 can be twisted together at the rear end of the optical fiber image transmission unit 1 and pass illumination light to the rear end of all the incident optical fibers 31 in the opposite direction of the illumination end 301 through a light source (not shown). Since the incident optical fiber 31 is soft and easy to bend, the technical solution of the outer ring illumination optical fiber group 3 arranged outside the optical fiber image transmission unit 1 can omit the prism that the endoscope system using the relay lens system and the magnifying glass system in the prior art needs to rely on, thereby further solving the technical problems of the complex structure, large volume, high assembly difficulty and high manufacturing cost of the endoscope system in the prior art.

[0038] In summary, in the fiber optic image transmission unit 1 disclosed in this embodiment, long-distance transmission and image amplification of the image are achieved through the optical fiber bundle 10, and technical problems such as the complex structure, low image transmission quality and poor image signal imaging quality of the endoscope imaging system that relies on the magnifying glass system and the relay glass system are solved, ultimately ensuring the imaging quality and image display effect.

[0039] Based on the technical solution included in the optical fiber imaging unit 1 disclosed in the aforementioned embodiment, the present application discloses a specific implementation of the optical fiber imaging system 100a.

[0040] Ginseng Figure 4 As shown, in this embodiment, the fiber optic imaging system 100a includes: an imaging unit 2 and a fiber optic image transmission unit 1 as disclosed in the above embodiment, which are sequentially arranged along the optical axis P from the object side, and at least one layer of outer ring illumination fiber group 3 circumferentially arranged outside the fiber optic image transmission unit 1. The imaging unit 2 and the fiber optic image transmission unit 1 are coaxially arranged with the optical axis P. The outer ring illumination fiber group 3 is intended to emit illumination light to the object side. Optionally, a plurality of incident optical fibers 31 circumferentially form a layer of outer ring illumination fiber group 3, or a plurality of incident optical fibers 31 circumferentially form two (or three) layers of outer ring illumination fiber group 3 to provide illumination for the area at the rear end of the imaging unit 2. The imaging unit 2 can be regarded as a double-sided convex lens between the output end 61 of the objective lens system 6 at the rear end of the measured object W and the optical fiber image transmission unit 1, or the imaging unit 2 can be regarded as a lens group composed of any several lenses in the prior art along the optical axis P to converge the image composed of the light incident on the image plane 21 of the objective lens system 6 to the optical fiber image transmission unit 1, so as to make the converged light incident on the receiving end surface 111 formed by splicing multiple optical fiber receiving ends 101. The optical parameters such as the rear focal plane M2 formed by the lens group as a whole can satisfy the following relationship, which will be described in detail below.

[0041] Combination Figure 1As shown, the outer ring illumination fiber group 3 forms an illumination end 301 facing the object side along the optical axis P, and the optical fiber receiving end 101 is arranged at intervals along the optical axis P and the illumination end 301 along the radial direction perpendicular to the optical axis P. The calculation formula of the distance between the image plane M1 of the imaging unit 2 and the back focal plane M2 of the imaging unit 2 is: X=If; wherein X refers to the distance between the image plane M1 of the imaging unit 2 and the back focal plane M2 of the imaging unit 2, I refers to the distance between the image plane M1 of the imaging unit 2 and the optical center 20 of the imaging unit 2, and f refers to the focal length of the imaging unit 2. The outer ring illumination fiber group 3 includes: a plurality of incident optical fibers 31 circumferentially arranged outside the optical fiber image transmission unit 1. The outer ring illumination fiber group 3 and the optical fiber image transmission unit 1 as a whole are also in the shape of a truncated cone. The image plane 21 of the objective lens system 6 and the back focal plane M2 of the imaging unit 2 are symmetrical relative to the imaging unit 2. Figure 1 The light emitted from the objective lens system 6 forms an incident light 22 from the image plane 21 of the objective lens system 6, and forms an outgoing light 23 after being refracted by the imaging unit 2. All the outgoing light 23 passing through the imaging unit 2 converges on the rear focal plane M2 of the imaging unit 2, and the rear focal plane M2 of the imaging unit 2 coincides with the receiving end surface 111 of the optical fiber receiving end 101 along the optical axis P. The image plane M1 of the imaging unit 2 is located along the optical axis P, separated from the rear focal plane M2 of the imaging unit 2 and close to the image side, thereby ensuring that the outgoing light 23 after refraction and convergence of the imaging unit 2 can at least be completely captured by the optical fiber bundle 10 to form an original image.

[0042] Based on the technical solution included in the optical fiber imaging unit 1 disclosed in the aforementioned embodiment, the present application discloses another specific implementation of the optical fiber imaging system 100b.

[0043] Ginseng Figure 5 , Figures 7 to 9 As shown, in this embodiment, the fiber optic imaging system 100b includes: an imaging unit 2 and a fiber optic image transmission unit 1 as disclosed in the above-mentioned embodiment, which are sequentially arranged along the optical axis P from the object side, at least one outer ring illumination fiber group 3 circumferentially arranged on the outside of the fiber optic image transmission unit 1, and a focusing unit 4 arranged between the imaging unit 2 and the illumination fiber group 3 along the optical axis P. Optionally, the focusing unit 4 is composed of a plurality of lenses 41 arranged in a circumferential ring along the optical axis P, so as to focus the illumination light emitted from the illumination end 301 and incident it onto the surface of the imaging unit 2, so as to form uniform incident light illumination. Further preferably, any one of the lenses 41 constituting the focusing unit 4 can at least completely cover the illumination range of the illumination light emitted from the illumination end 301 formed by the incident optical fiber 31. Figure 5 As shown, the illumination range of the illumination light emitted by any lens 41 is the circular illumination area covered by the dotted line 302 and the dotted line 303. Of course, the aforementioned lens 41 is only an optional implementation and can be understood as a double convex lens or a single convex lens.

[0044] Ginseng Figure 8and Fig. 9 As shown, as a reasonable deformation of the aforementioned focusing unit 4, the present embodiment further discloses a focusing unit 4a, which has convex arc surfaces on both sides along the optical axis P, and the illumination light emitted from the illumination end 301 is refracted and converged from the convex arc surface 4a2 through the focusing unit 4a, and then emitted from the convex arc surface 4a1. The focusing unit 4a is radially rotated and sectioned along the optical axis P, and any cross section of the focusing unit 4a forms a convex arc surface 4a1 and a convex arc surface 4a2, thereby converging the illumination light. Compared with the aforementioned focusing unit 4, the focusing unit 4a does not need to strictly align each lens 41 with the illumination end 301, thereby further simplifying the assembly difficulty of the optical fiber imaging system 100b and further improving the focusing effect of the focusing unit. Figure 1 and Figure 5 As shown, the outer ring illumination optical fiber group 3 and the optical fiber image transmission unit 1 as a whole are also in the shape of a truncated cone.

[0045] Ginseng Figure 5 As shown, the illumination fiber group 3 forms an illumination end 301 facing the object side along the optical axis P, and the end face of the optical fiber receiving end 101 and the end face of the illumination end 301 are both located in a plane Q perpendicular to the optical axis P. The calculation formula for the distance between the illumination end 301 and the optical center 40 of the focusing unit 4 is: Among them, L A Refers to the distance between the illumination end 301 and the optical center 40 of the focusing unit 4, and the illumination end 301 in this embodiment coincides with the receiving end face 111, X refers to the distance between the illumination end 301 and the rear focal plane M2 of the imaging unit 2, and f1 refers to the focal length of the focusing unit 4. The outer ring illumination fiber group 3 includes: a plurality of incident optical fibers 31 circumferentially arranged outside the optical fiber image transmission unit 1. The image plane M1 of the imaging unit 2 coincides with the receiving end face 111 of the optical fiber receiving end 101. The circular illumination area formed by the focusing unit 4 (or the focusing unit 4a) can at least completely cover all incident light rays 22 incident on the optical fiber receiving end 101. Figure 1 The light emitted from the objective lens system 6 forms an incident light 22 from the image plane 21 of the objective lens system 6, and then forms an outgoing light 23 after being refracted by the imaging unit 2. All the outgoing light 23 passing through the imaging unit 2 converges on the image plane M1 of the imaging unit 2. The distance between the rear focal plane M2 of the imaging unit 2 and the optical center 40 of the focusing unit 4 along the optical axis P is L. B , and X=L A +L B .

[0046] The technical solutions of the fiber optic imaging system 100b disclosed in this embodiment and the fiber optic imaging system 100a in the aforementioned embodiment are the same as those in the aforementioned embodiment and will not be repeated here.

[0047] Based on the technical solution included in the optical fiber imaging unit 1 disclosed in the aforementioned embodiment, the present application discloses another specific implementation of the optical fiber imaging system 100c.

[0048] Ginseng Figure 6 As shown, in this embodiment, the fiber optic imaging system 100c includes: an imaging unit 2 and a fiber optic image transmission unit 1 as disclosed in the above-mentioned embodiment, which are sequentially arranged along the optical axis P from the object side, and at least one layer of an outer ring illumination fiber group 3 circumferentially arranged on the outside of the fiber optic image transmission unit 1. The outer ring illumination fiber group 3 includes: a plurality of incident optical fibers 31 circumferentially arranged on the outside of the fiber optic image transmission unit 1. The fiber optic receiving end 101 is arranged at intervals along the optical axis P relative to the illumination end 301 along a radial direction perpendicular to the optical axis P, and the outer ring illumination fiber group 3 and the fiber optic image transmission unit 1 as a whole are also in the shape of a truncated cone. The fiber optic image transmission unit 1 includes: a first lens 13 arranged at the fiber optic receiving end 101 along the optical axis P, and the first lens 13 has an object end face 131 and an image end face 132, both of which are planes. The first lens 13 is used as Figure 4 A variation of Figure 4 The area between the optical fiber receiving end 101 and the lighting end 301 is air. In this embodiment, the air is filled with the first lens 13, which not only protects the front end face of the optical fiber bundle 10 (i.e., the optical fiber receiving end 101) and plays an isolation and protection role, but also the first lens 13 can more conveniently implement the coating process, which is much simpler than coating the end face of the optical fiber bundle 10, the uniformity of the film layer will be high, and the filtering and transmittance increase effects will be better.

[0049] The illumination fiber group 3 forms an illumination end 301 facing the object side along the optical axis P, and the first lens 13 forms an object end surface 131 facing the object side along the optical axis P, and the end surface of the illumination end 301 is located in the same plane Q perpendicular to the optical axis P, so as to ensure that the end surface of the illumination end 301 coincides with the plane Q. The first lens 13 is used for optical path difference compensation in the optical fiber imaging system 100c. The calculation formula of the thickness of the first lens 13 along the optical axis P is: Wherein, ΔL refers to the thickness of the first lens 13 along the optical axis P, n refers to the refractive index of the first lens 13, and X refers to the distance between the image plane M1 of the imaging unit 2 and the rear focal plane M2 of the imaging unit 2 when the optical fiber image transmission unit 1 does not include the first lens 13. In this embodiment, the focal length of the imaging unit 2 is f2, and the optical fiber receiving end 101 is collapsed toward the image side compared to the illumination end 301, and ensures that the image plane M1 of the imaging unit 2 is located between the rear focal plane M2 of the imaging unit 2 and the image end surface 132 (i.e., the exit plane of the first lens 13) along the optical axis P. The first lens 13 is surrounded by the outer ring illumination fiber group 3, and the first lens 13 forms an object end surface 131 facing the object side along the optical axis P and is flush with the illumination end 301. Figure 1The light emitted from the objective lens system 6 forms an incident light ray 22 from the image plane 21 of the objective lens system 6, and is refracted by the imaging unit 2 to form an outgoing light ray 23. All the outgoing light rays 23 passing through the imaging unit 2 converge on the first lens 13 to form an object end surface 131 facing the object side along the optical axis P. The refracted light ray 24 formed by the outgoing light ray 23 being refracted by the object end surface 131 converges on the first lens 13 to form an image end surface 132 facing the object side along the optical axis P (that is, the exit plane of the first lens 13), and the image end surface 132 coincides with the receiving end surface 111 formed by the optical fiber receiving end 101, thereby ensuring that the converged outgoing light 23 can be completely captured by the receiving end surface 111 to form an original image, and then the original image is transmitted over a long distance and amplified through the optical fiber bundle 10.

[0050] The technical solutions of the fiber optic imaging system 100c disclosed in this embodiment and the fiber optic imaging system 100a or the fiber optic imaging system 100b in the aforementioned embodiments are described in the aforementioned embodiments and will not be repeated here.

[0051] Combination Figures 1 to 9 As shown, based on the technical solutions included in the above-mentioned specific embodiments, the present application also discloses an optical detection device 1000, which includes: a fiber optic imaging system as described in any of the above-mentioned embodiments arranged with the same optical axis P, and an image acquisition unit 5 located on the image side. The fiber optic imaging system in this embodiment includes a fiber optic imaging system 100a or a fiber optic imaging system 100b or a fiber optic imaging system 100c. The specific technical solution of the fiber optic imaging system included in the optical detection device 1000 disclosed in this embodiment is described in the above-mentioned embodiments and will not be repeated here. The optical detection device 1000 can be configured in an endoscope system and regarded as a part of the endoscope system.

[0052] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

[0053] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0054] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An optical fiber image transmission unit, which is completely encapsulated in a housing, characterized in that: include: An optical fiber bundle having a plurality of image transmission optical fibers and an isolation layer, wherein the optical fiber bundle forms an optical fiber receiving end facing the object side and an optical fiber emitting end facing the image side along the optical axis, and the plurality of image transmission optical fibers are closely arranged in the isolation layer, and the cross section of the image transmission optical fiber is one of a regular triangle, a regular quadrilateral, and a regular hexagon; The image transmission optical fiber forms a receiving end face for receiving an image at the optical fiber receiving end, and forms an output end face for outputting an image at the optical fiber output end; The ratio of the receiving end face area to the emitting end face area is 1:N, N is greater than 1, and the transverse cross-sectional area of ​​the image transmission optical fiber along the perpendicular direction to the optical axis increases uniformly from the optical fiber receiving end to the optical fiber emitting end, so as to output the amplified image through the emitting end face; The optical fiber receiving end completely covers the outgoing light rays converged by the imaging unit located on the object side.

2. The optical fiber image transmission unit according to claim 1, characterized in that: The optical fiber bundle is composed of a plurality of image transmission optical fibers with the same cross-sectional specifications and sizes arranged in a cluster along the optical axis.

3. The optical fiber image transmission unit according to claim 2, characterized in that: When N is equal to 4, the ratio of the side length of the image transmission optical fiber at the receiving end face to the side length at the output end face is 1:2, the ratio of the area of ​​the receiving end face to the area of ​​the output end face is 1:4, and the image received by the receiving end face is magnified four times and output through the output end face.

4. The optical fiber image transmission unit according to claim 1, characterized in that: The optical fiber receiving end is provided with an anti-reflection optical film.

Images