Optical path multiplexing device

Abstract

The invention relates to the technical field of light sources, in particular to an optical path multiplexing device, which comprises a first channel, a second channel and a third channel, a first guide part, a second guide part and a third guide part are respectively arranged in the first channel, the second channel and the first channel are intersected, and a dichroscope is correspondingly arranged at the output end of the second channel; the third channel and the second channel are arranged in parallel or approximately parallel, and the output end of the third channel is correspondingly provided with a semi-reflecting and semi-transmitting mirror; the intensified gathering assembly is used for gathering a total light source mixed by the three light sources and comprises a first gathering assembly and a second gathering assembly, and the first gathering assembly is used for gathering the total light source for the first time step by step; and the second gathering assembly is used for expanding the divergence angle of the total light source and then gathering the total light source for the second time. The light source multiplexing system provided by the invention has higher stability.

Description

[0001] Priority application

[0002] This application claims priority to Chinese invention patent application filed on August 14, 2024, [202411117152.X], entitled "[An endoscope, imaging device, optical path multiplexing device and system]", which is incorporated herein by reference in its entirety. Technical Field

[0003] This invention relates to the field of light source technology, and more specifically to an optical path multiplexing device. Background Technology

[0004] Medical endoscopes require illumination to observe the relatively dark cavities within the body. Generally, based on the method of setting up the cold light source, medical endoscopes can be divided into two types. One approach uses a halogen lamp or high-power LED as the light source, and uses optical fibers to transmit the light emitted by the halogen lamp or high-power LED to the endoscope lens for illumination; the other approach mounts the LED at the end of the endoscope lens and installs an outer cover made of insulating transparent material, using the LED at the end of the endoscope lens to provide illumination.

[0005] However, existing light source technologies all have many drawbacks. For example, endoscopes using fiber optic transmission are large, complex in structure, and consume a lot of energy. Furthermore, considering the high cost of fiber optic endoscopes, they are usually reused after disinfection and sterilization. However, due to the complex structure of endoscopes, thorough disinfection and sterilization are impossible, and reuse poses a risk of cross-infection.

[0006] See patent application CN215729084U, which provides an endoscope light source device and system. It employs a first LED light source unit emitting a first light beam; a second LED light source unit emitting a second light beam; a third LED light source unit emitting a third light beam; an optical color combining module capable of combining the first, second, and third light beams into a white light beam; a predetermined wavelength monochromatic light source unit, one or more of which emit a monochromatic light beam of a predetermined wavelength; and a switching unit capable of switching the endoscope's light source device to emit one of the following: a first light beam, a second light beam, a third light beam, a white light beam, and a monochromatic light beam. For example, patent application CN115227187A discloses an endoscope light source device and system, comprising: at least two light source units; at least one dichroic mirror used to perform long-wavelength cutoff filtering, short-wavelength cutoff filtering, or narrowband filtering on the emitted light from the corresponding light source units, and to output synthesized light after optical path integration of the filtered beams.

[0007] However, using multiple light sources together can easily lead to significant power loss and low efficiency. Therefore, there is an urgent need for a multiplexing device that can improve the utilization efficiency of light sources. Summary of the Invention

[0008] The purpose of this invention is to provide an optical path multiplexing device that partially solves or alleviates the above-mentioned deficiencies in the prior art.

[0009] To solve the aforementioned technical problems, the present invention specifically adopts the following technical solution: an optical path multiplexing device, comprising: a first channel for introducing a first light source, wherein a first guiding part is disposed within the first channel, the first guiding part being used to guide and convert the first light source having a first divergence angle into first parallel light; a second channel for introducing a second light source, wherein the second channel intersects with the first channel, a second guiding part is disposed within the second channel, the second guiding part being used to guide and convert the second light source having a second divergence angle into second parallel light, and a dichroic mirror is correspondingly disposed at the output end of the second channel, wherein the first parallel light and the first light source have a first divergence angle. The second parallel light is converged into at least one mixed parallel light beam by the dichroic mirror; a third channel is provided for introducing a third light source, and the third channel is arranged parallel or approximately parallel to the second channel. A third guide portion is provided within the third channel to convert the third light source with a third divergence angle into third parallel light. A semi-reflective lens is correspondingly provided at the output end of the third channel, and the third parallel light and the mixed parallel light are converged into at least one total light source by the semi-reflective lens. An enhancing focusing component is provided along the transmission direction of the total light source to focus the total light source, and the enhancing focusing component includes:

[0010] A first focusing component is used to sequentially focus the total light source for the first time. The first focusing component includes a first convex-concave lens, a second convex-concave lens, and a plano-concave lens arranged sequentially along the transmission direction of the total light source. The first convex surface of the first convex-concave lens and the second convex surface of the second convex-concave lens are both oriented towards the direction of incidence of the total light source, while the third concave surface of the plano-concave lens is opposite to the second concave surface of the second convex-concave lens. A second focusing component is used to expand the divergence angle of the total light source and subsequently focus it for the second time. The second focusing component includes a first biconvex lens and a second biconvex lens arranged sequentially along the transmission direction of the total light source. The first biconvex lens has a third convex surface and a fourth convex surface, and the radius of curvature of the third convex surface is greater than that of the fourth convex surface. The second biconvex lens has a fifth convex surface and a sixth convex surface, and the radius of curvature of the fifth convex surface is smaller than that of the sixth convex surface.

[0011] In some embodiments, the light-blocking plate further includes a first light-blocking plate having a first inner hole, the first light-blocking plate being disposed between the first gathering component and the second gathering component, and the first radius of the first inner hole satisfying the following setting rule: the first radius is smaller than the diameter of the plano-concave lens, and the first radius is smaller than the diameter of the first biconvex lens.

[0012] In some embodiments, the device further includes an optical fiber, wherein the input end of the optical fiber is disposed toward the output end of the second focusing component, and the diameter of the input end of the optical fiber is smaller than the diameter of the second biconvex lens.

[0013] In some embodiments, the diameter of the second convex-concave lens is smaller than the diameter of the first convex-concave lens.

[0014] In some embodiments, the thickness of the second convex-concave lens is greater than the thickness of the first convex-concave lens.

[0015] In some embodiments, the first guide portion includes: a first guide lens arranged sequentially along the transmission direction of the first light source, and the first guide lens having a first guide convex surface and a first conical surface; and a first plano-convex lens, wherein the plane of the first plano-convex lens is disposed facing the first conical surface.

[0016] In some embodiments, the second guide portion includes: a second guide lens arranged sequentially along the transmission direction of the second light source, and the second guide lens having a second guide convex surface and a second conical surface; and a second plano-convex lens, with the plane of the second plano-convex lens facing the second conical surface.

[0017] In some embodiments, the third guide portion includes: a third guide lens arranged sequentially along the transmission direction of the third light source, wherein the first guide lens has a third guide convex surface and a third conical surface; and a third plano-convex lens, wherein the plane of the third plano-convex lens is disposed facing the third conical surface.

[0018] In some embodiments, the device further includes a second light-blocking plate having a second inner hole, and the second light-blocking plate being disposed between the semi-reflective lens and the first focusing component.

[0019] In some embodiments, the wavelength range of the first light source includes 492nm-577nm, and the wavelength range of the second light source includes 380nm-455nm. In some embodiments, the wavelength range of the third light source includes 400nm-770nm; or, the wavelength range of the third light source includes 620nm-770nm.

[0020] Beneficial Technical Effects: This invention provides an optical path multiplexing device that controls the divergence angle of the incident light source and the light loss generated during transmission, thereby improving the utilization rate of the light source. Specifically, the enhanced focusing component provided in this invention is designed with several coordinated focusing stages for the mixed beam: 1) A combination of a biconvex-concave lens and a plano-concave lens is used to gradually reduce the divergence angle of the total light source (i.e., perform the first focusing operation); 2) For the total light source after the first focusing, edge stray light is filtered (i.e., stray light at the edge of the mixed beam is filtered through a first light-blocking plate); 3) The filtered mixed beam undergoes divergence angle diffusion and a second focusing.

[0021] In other words, this embodiment focuses on strengthening the focusing design at the fiber optic inlet to significantly reduce the loss generated during beam mixing and transmission. Furthermore, experimental verification has shown that this angle-reduction-diffusion-reduction transmission mode effectively reduces the spot size of the mixed light, making it smaller than the size of the fiber's input end, while mitigating the loss problem during spot reduction. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. The elements or parts in the drawings are not necessarily drawn to scale. Obviously, the drawings described below are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0023] Figure 1 This is a schematic cross-sectional view of the endoscope in an exemplary embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the imaging segment in an exemplary embodiment of the present invention;

[0025] Figure 3 This is a partial structural schematic diagram of the relay imaging segment in an exemplary embodiment of the present invention;

[0026] Figure 4 This is a partial structural diagram of the imaging segment in an exemplary embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of an endoscope structure in an exemplary embodiment of the present invention.

[0028] Figure 6 Waveform aberration diagram of an endoscope according to an exemplary embodiment of the present invention;

[0029] Figure 7 This is a schematic diagram of field curvature and distortion of an exemplary embodiment of the present invention;

[0030] Figure 8 This is a schematic diagram of system distortion in an exemplary embodiment of the present invention;

[0031] Figure 9 This is a schematic diagram of on-axis lateral aberration in an exemplary embodiment of the present invention;

[0032] Figure 10a This is a first photograph of the oral mucosal surface observed by an exemplary endoscope of the present invention;

[0033] Figure 10b This is a second photograph of the oral mucosal surface observed by an exemplary endoscope of the present invention;

[0034] Figure 10c This is a third photograph of the oral mucosa surface observed by an exemplary endoscope of the present invention;

[0035] Figure 10d This is a fourth photograph of the oral mucosa surface observed by an exemplary endoscope of the present invention;

[0036] Figure 10e This is a fifth photograph of the oral mucosa surface observed by an exemplary endoscope of the present invention;

[0037] Figure 10f This is a sixth photograph of the oral mucosa surface observed by an exemplary endoscope of the present invention;

[0038] Figure 10g This is the seventh photograph of the oral mucosa surface observed by an exemplary endoscope of the present invention;

[0039] Figure 10h This is the eighth photograph of the oral mucosa surface observed by an exemplary endoscope of the present invention;

[0040] Figure 11 This is a partial structural diagram of an optical path multiplexing component in an exemplary embodiment of the present invention;

[0041] Figure 12 This is a schematic diagram of the structure of a ring-shaped diffuser film;

[0042] Figure 13a This is a schematic diagram of the structure of an optical path multiplexing device in an exemplary embodiment of the present invention;

[0043] Figure 13b This is a cross-sectional schematic diagram of an optical path multiplexing device in an exemplary embodiment of the present invention;

[0044] Figure 13cThis is a schematic diagram showing the distribution of lenses in an exemplary embodiment of the present invention;

[0045] Figure 13d This is a schematic diagram of the light source transmission path of the coupling lens in an exemplary embodiment of the present invention;

[0046] Figure 14a Schematic diagrams of the spectra at wavelengths of 405 nm and 415 nm;

[0047] Figure 14b This is a schematic diagram of the spectrum at a wavelength of 560 nm;

[0048] Figure 14c This is a schematic diagram of the spectrum at a wavelength of 620 nm;

[0049] Figure 14d This is a schematic diagram of the spectrum of a white LED;

[0050] Figure 14e A schematic diagram of the emission spectrum of a white light chip using R, G, and B primary color LEDs;

[0051] Figure 14f This is a schematic diagram of the light distribution curve of an LED;

[0052] Figure 15 This is a schematic diagram of the light spot of the main light source at position P1 on the plane.

[0053] Figure 16 This is a schematic diagram of the light spot of the main light source at position P2 on the plane.

[0054] Figure 17 The light intensity of the total light source at position P1 in plane P1;

[0055] Figure 18 Let be the light intensity of the total light source at position P2 in plane.

[0056] Figure reference numerals: 10 is the objective lens section, 11 is the first lens, 12 is the second lens, 13 is the first aperture stop, 14 is the third lens, 15 is the second aperture stop, 151 is the through hole, 16 is the fourth lens, 17 is the locking structure, 10A is the second sleeve, 10B is the first sleeve; 20 is the relay imaging section, 21 is lens I, 22 is lens II, 23 is lens III, 24 is lens IV, 25 is lens V, 20A is the first lens group, 2 0B is the second lens group, 20C is the third lens group; 30 is the imaging section, 31 is the first cemented doublet achromatic lens, 32 is the biconcave lens, 33 is the second cemented doublet achromatic lens, 34 is the negative meniscus lens, 35 is the fixing sleeve, 36 is the first fixing structure, 37 is the second fixing structure, 38 is the third fixing structure; 40 is the reflecting lens; 051 is the connecting seat, 052 is the focusing ring, 053 is the camera mount, and 054 is the camera;

[0057] 01 is the first light source, 51 is the first guide part, 511 is the first guide lens, 511a is the first guide convex surface, 511b is the first conical surface, and 512 is the first plano-convex lens; 02 is the second light source, 52 is the second guide part, 521 is the second guide lens, 521a is the second guide convex surface, 521b is the second conical surface, 522 is the second plano-convex lens; 53 is the third guide part, 531 is the first guide lens, 531a is the third guide convex surface, 531b is the third conical surface, and 532 is the third plano-convex lens. Lens 55 is a dichroic mirror, 03 is a third light source, 56 is a semi-reflective semi-transparent lens, 58 is a strengthening focusing component, 58A is a first focusing component, 581 is a first convex-concave lens, 582 is a second convex-concave lens, 583 is a plano-concave lens, 58B is a second focusing component, 584 is a first biconvex lens, 585 is a second biconvex lens, 584a is a third convex surface, 584b is a fourth convex surface, 585 is a second biconvex lens, 585a is a fifth convex surface, 585b is a sixth convex surface, and 586 is a first light-blocking plate. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0059] In this document, suffixes such as "module," "component," or "unit" used to denote elements are used solely for the purpose of illustrative purposes and have no specific meaning in themselves. Therefore, "module," "component," or "unit" can be used interchangeably. In this document, terms such as "upper," "lower," "inner," "outer," "front," "rear," "one end," and "the other end," indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In this document, unless otherwise expressly specified and limited, terms such as "installed," "equipped with," and "connected" should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; it can be a connection within two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. In this document, "and / or" includes any and all combinations of one or more of the listed related items. "Multiple" in this document means two or more, i.e., it includes two, three, four, five, etc. It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0060] As used in this specification, the term "approximately" typically means + / - 5% of the value, more typically + / - 4%, more typically + / - 3%, more typically + / - 2%, even more typically + / - 1%, and even more typically + / - 0.5%. In this specification, some embodiments may be disclosed in a range format. It should be understood that this "range" description is merely for convenience and brevity and should not be construed as a rigid limitation on the disclosed range. Therefore, a range description should be considered as having specifically disclosed all possible subranges and individual numerical values ​​within that range. For example, a description of the range 1-6 should be considered as having specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and individual numbers within that range, such as 1, 2, 3, 4, 5, and 6. The above rules apply regardless of the breadth of the range.

[0061] In this article, a "lens" is a device made according to the laws of light refraction. A lens is a refracting mirror whose refractive surface is a transparent body consisting of two spherical surfaces (or a portion of a spherical surface) and a plane. It forms both real and virtual images. In this article, a "cemented lens" is a lens obtained by cementing two or more lenses together (for example, two lenses cemented together are also called a bilayer lens). In this article, a "semi-transparent and semi-reflective mirror" is also called a beam splitter, beam splitter, or semi-reflective half-lens. A semi-transparent and semi-reflective mirror is a type of coated glass with one or more thin films deposited on its surface. When a beam of light is projected onto the coated glass, it is split into two or more beams through reflection and refraction. In this article, the "divergence angle" refers to the angle at which the light beam spreads out in space after originating from the light source. In this article, the "light spot" refers to the intensity distribution of light within a circular area formed on a diffuse reflector when the light beam is perpendicular to the transmission direction.

[0062] The structure inside the oral cavity is quite complex, with an extremely uneven and irregular surface. Therefore, doctors usually need to manually find the best observation position in the complex oral environment in order to obtain image data from these observation positions.

[0063] Currently, there are generally two types of endoscopes: rigid straight-tube endoscopes (typically used in otolaryngology, nasal cavity examinations, and general surgery) and flexible tube endoscopes that can be bent and deformed at will. The applicant found that rigid tube endoscopes are difficult to adjust in terms of angle when used for oral cavity observation, and the range of adjustment is extremely limited, resulting in persistent blind spots.

[0064] Furthermore, while the deformability of the tubing can improve the flexibility of angle adjustment to some extent, the adjustment of the tubing is also highly arbitrary. This means that even highly experienced physicians need to make repeated adjustments to achieve the correct observation angle. Frequent adjustments can cause severe discomfort to the patient.

[0065] In fact, for patients who may already have oral diseases (such as oral ulcers), this adjustment process may further damage the oral cavity.

[0066] Example 1

[0067] To address the aforementioned technical problems, unlike traditional arbitrary angle adjustment techniques, this invention proposes a solution with a fixed bending angle. Furthermore, the applicant unexpectedly discovered that this three-point limiting scheme, which coordinates the values ​​at three points—the bending angle of the tube, the head of the tube, and the end of the tube (i.e., the included angle, length L1, and length L2)—integrates advantages such as convenient adjustment of the observation angle, comprehensiveness of the observation angle, and clarity of observation in rigid endoscopes.

[0068] Furthermore, because this rigid endoscope significantly improves the ease of operation for doctors, allowing them to more easily adjust and find the optimal observation angle within the oral cavity, it can effectively avoid or reduce patient discomfort during the adjustment process. In other words, the endoscope provided in this embodiment coordinates the selection of limited combinations of factors such as the lengths of the objective lens segment and the cemented lens segment, as well as the bending angle between the objective lens segment and the cemented lens segment. This allows the endoscope's three-point limiting scheme to meet the observation angle requirements at different positions within the oral cavity.

[0069] Furthermore, the rigid, flexible endoscope design of this invention makes it easier for doctors to control the distance between the endoscope tip and the oral cavity surface when operating the endoscope to observe the angle inside the mouth. This avoids the endoscope directly rubbing against too much skin surface, thus optimizing the patient's medical experience.

[0070] Especially for young patients (such as infants and toddlers), it is very difficult for them to cooperate with the doctor to complete the examination if they experience significant discomfort during the process. However, the three-point limiting scheme adopted in this invention can be adjusted to the observation angle more conveniently (thus reducing the number of times the doctor tries to adjust the observation angle), thereby accelerating the oral examination process and significantly reducing the patient's discomfort.

[0071] In some embodiments, the width of the objective lens segment is 0.3-1.0 cm. In some embodiments, the width of the relay imaging segment is 0.3-1.0 cm. The widths of the objective lens segment and the relay imaging segment refer to the width of the lens within them.

[0072] In this embodiment, the applicant discovered that by comprehensively setting the bending angle, head, end, and width of the tube, the observation needs of sensitive areas such as the gums and deep buccal tissue can be met. Even when applied to patients with limited oral space (such as young patients), it can meet the doctor's needs for adjusting the observation angle.

[0073] In some embodiments, the objective lens segment is provided with a negative power lens, a positive power lens, a cemented doublet achromatic lens, and a plano-convex lens sequentially from its input end to its output end. The two ends of the objective lens segment along the image transmission direction are referred to as the input end and the output end, respectively.

[0074] In some embodiments, a first aperture stop is provided between the negative power lens and the positive power lens, and a second aperture stop is provided between the positive power lens and the cemented doublet achromatic lens.

[0075] This embodiment further considers the impact of the concave and convex planes within the oral cavity on image clarity. Therefore, by setting a first aperture, a second aperture, and various lenses in sequence, the incident angle of the optical fiber can be reduced, the depth of focus can be increased, and thus ensure that all sites with different distances from the end can be clearly imaged. This also makes it easier to distinguish fine details and subtle differences in tissue structure.

[0076] In this context, depth of focus is short for focal depth. In an optical imaging system, the depth of focus refers to the range within which the image plane can move when the change in system wave aberration caused by movement of the image plane does not exceed one-quarter of a wavelength.

[0077] Preferably, the depth of focus of the objective lens can be set to approximately 0.5cm-1cm.

[0078] It is worth noting that the rigid endoscope in this invention will also have better optical stability:

[0079] Less image distortion: The rigid structure of a rigid endoscope minimizes image distortion and aberrations, resulting in a more accurate presentation of the area being examined. In contrast, flexible endoscopes can cause image distortion due to bending and twisting of the fiber bundle.

[0080] Consistent focus: The optics of a rigid endoscope, with its specific bending angle and length settings, are fixed and stable, thus maintaining a consistent focus and depth of field. This is especially important for capturing accurate and reliable images.

[0081] Furthermore, this rigid endoscope with a specific angle will also have a robust structure. The rigid design of the rigid endoscope makes it more durable and resistant to damage caused by bending or twisting. This robustness can extend its service life and reduce maintenance costs. The endoscope with a specific angle provided by this invention has a simple structure, which also helps to control its manufacturing cost.

[0082] Rigid endoscopes can be simpler to construct and operate because they do not require the complex mechanisms necessary for the flexibility of flexible endoscopes. This makes them easier to use and maintain.

[0083] Easier to clean and sterilize: The robust structure of rigid endoscopes makes the cleaning and sterilization process simpler, thereby reducing the risk of contamination and ensuring a higher level of hygiene.

[0084] Furthermore, the present invention also provides a rigid endoscope with a specific bending angle, comprising:

[0085] A tube for transmitting images, the tube comprising:

[0086] The tube comprises an objective lens section having a first axis and a length of 0.5-2.5 cm; a relay imaging section having a second axis, wherein the angle α between the first and second axes is 110°-135° and the length of the relay imaging section is 3-10 cm; a reflecting lens is provided at the intersection of the first and second axes; the tube wall corresponding to the junction of the objective lens section and the relay imaging section is made of rigid material; and an imaging section is connected to the output end of the tube.

[0087] Unlike traditional free-angle adjustment settings (such as flexible tubes that can deform arbitrarily), the bending tube provided by this invention directly adopts a specific angle setting scheme, rather than pursuing a highly flexible variable angle design. However, this rigid bending tube with a specific angle, in conjunction with the objective lens section and the relay imaging section, can not only meet the multi-angle observation needs in the oral cavity, but also provide clear imaging and facilitate manual adjustment by doctors.

[0088] In some embodiments, the imaging segment is provided with the following components sequentially from its first end to its second end (i.e., the direction of image transmission): a first cemented doublet achromatic lens 31, a biconcave lens 32, a second cemented doublet achromatic lens 33, and a negative meniscus lens 34; wherein the first cemented doublet achromatic lens 31, the second cemented doublet achromatic lens 33 and the biconcave lens 32 cooperate to eliminate chromatic aberration in the image, and the negative meniscus lens 34 is further used to correct aberrations.

[0089] In some embodiments, the relay imaging segment is further connected to an optical path multiplexing component, which is used to provide input light to the relay imaging segment. The input light is transmitted sequentially to the area to be observed through the relay imaging segment and the objective lens segment.

[0090] In some embodiments, during use, the endoscope can also be covered with a protective film (or a disposable anti-fouling film) on its objective lens section, which also helps to reduce the cleaning burden after use.

[0091] Unlike ear, nose, or other general surgical examinations, oral examinations have the following unique characteristics:

[0092] 1. Limited space: The oral cavity has a complex anatomical structure and limited space, which can be challenging for navigating rigid instruments without causing discomfort or injury.

[0093] 2. Curvature and angle: The oral cavity contains many curves and angles, which makes it difficult for traditional endoscopes to easily navigate / reach the area being examined, thus limiting their effectiveness in providing a comprehensive examination.

[0094] 3. Patient discomfort: The use of an endoscope in the mouth can be uncomfortable for patients, especially when the procedure requires navigation around sensitive areas such as the gums and deep cheeks.

[0095] 4. Discomfort for doctors: Rigid endoscopes, because they cannot be bent or adjusted to fit the contours of the oral cavity, impose limitations on examinations. While flexible endoscopes offer greater flexibility and maneuverability, they require two-handed control, increasing the complexity and discomfort for doctors, especially when accessing hard-to-reach areas.

[0096] 5. Risk of injury: Both flexible and rigid endoscopes are inconvenient to adjust in terms of observation angle, and there is a high risk of damage to the delicate oral tissues, which makes the examination more challenging and less safe.

[0097] Currently, oral examinations, which involve adjusting different viewing angles, can often only be performed using a flexible endoscope.

[0098] However, the applicant unexpectedly discovered that by coordinating the values ​​at three points—the bending angle of the tube, the head of the tube, and the end of the tube—this rigid endoscope could effectively solve the aforementioned problems.

[0099] Specifically, this invention proposes a rigid endoscope with a specific bending angle (and the bending point is made of a rigid material to fix the bending angle), objective lens length, and relay imaging segment length. When navigating sensitive areas such as the gums and deep buccal region (where the operable space is extremely narrow and the doctor's line of sight is easily obstructed when observing the actual position of the endoscope probe), it can greatly improve the adjustment of the observation angle and the patient's examination experience.

[0100] The technical solution protected by this invention will be specifically described below through an exemplary embodiment:

[0101] See Figures 1-5 As shown, the present invention provides an endoscope. The endoscope includes:

[0102] Objective lens section 10, which has a first axis;

[0103] The relay imaging segment 20 has a second axis, and the first axis and the second axis intersect to form an included angle α.

[0104] A reflector (also referred to as a reflective lens 40) is disposed in the area where the first axis and the second axis intersect to reflect the image output by the objective lens section 10 and guide the reflected image to the relay imaging section 20; that is, the included angle α can also refer to the sum of the incident angle and the reflection angle of the image on the reflector.

[0105] Imaging segment 30; the objective lens segment 10, the relay imaging segment 20 and the imaging segment 30 are connected in sequence to transmit the image observed at the first end of the objective lens segment 10 (the end facing the area to be observed) to the imaging segment for imaging.

[0106] The objective lens section 10 includes: a first lens 11; the first end of the first lens has a flat surface, and the second end has an inwardly recessed concave surface; a second lens 12, the first end of the second lens 12 is disposed facing the second end of the first lens, and has a flat surface; the second end of the second lens 12 has an outwardly protruding surface; a first aperture 13 is disposed between the first lens 11 and the second lens 12; a third lens 14, a second aperture 15 is disposed between the third lens 14 and the second lens; the second aperture 15 is provided with a through hole 151, and the inner diameter of the through hole gradually increases along the direction from its first end to its second end, and its first end and second end are sequentially connected to the second lens 12 and the third lens 14; a fourth lens 16, the first end of the fourth lens has a protruding surface; and a locking structure 17 is disposed between the third lens 14 and the fourth lens 16 to fix a certain size gap between the third lens 14 and the fourth lens 16.

[0107] An aperture stop is an entity in an optical system that limits the beam of light.

[0108] In some embodiments, the first lens 11 is a negative power lens. In some embodiments, the second lens 12 is a positive power lens. In some embodiments, the third lens 14 is a cemented doublet achromatic lens. In some embodiments, the fourth lens 16 is a plano-convex lens.

[0109] See Figure 2 As shown, the endoscope also includes: a first sleeve 10B, which is used to install and fix the lens, and a second sleeve 10A, which is disposed outside the first sleeve 10B to protect the first sleeve.

[0110] In this embodiment, the aperture setting can reduce the angle of light incidence, thus increasing the depth of focus. Therefore, within a specific depth of focus range, the image is sharp.

[0111] The objective lens in this embodiment features a short focal length, a large field of view, and a long optical length. The structure is designed with an anterior and posterior focal depth of approximately 2.5 mm, totaling about 5 mm. Due to the complex structure of the oral cavity, the observation surface is not usually in a single plane; it is a three-dimensional structure. The Z-axis direction (i.e., the axis perpendicular to the observed surface) of this three-dimensional structure is within 5 mm, resulting in clear imaging.

[0112] Furthermore, it has been verified that when observing the oral mucosa, the imaging of the mucosal surface and the tissue structure 2mm below the surface is clear.

[0113] Furthermore, the reflecting lens is installed inside the angle of the probe (i.e., the "tube") to refract the imaging light path. The angle between the optical principal axis of the objective lens group (i.e., the first axis) and the optical principal axis of the lens in the imaging section (i.e., the second axis) can preferably be about 110 degrees.

[0114] Furthermore, the relay imaging section, also known as the optical image-transfer lens group, preferentially uses HOPKINS rod lenses, which consist of two rod-shaped mirrors with negative lenses attached, and the aperture stops are located in symmetrical positions.

[0115] Furthermore, taking into account both operational flexibility and ease of production, the width of the objective lens section can be set to approximately 0.4-0.65 cm, and the width of the relay imaging section can be set to approximately 0.4-0.65 cm.

[0116] Furthermore, the endoscope adapter (also known as the imaging section) is the transition system between the endoscope eyepiece and the CCD imaging system. Its initial structure consists of a front protective glass, a cemented doublet achromatic lens, a biconcave lens, another cemented doublet achromatic lens, and a negative meniscus lens in that order. To elaborate further, the adapter is fully fitted into a metal sleeve, and the zoom function is achieved by moving the sleeve back and forth using a spiral guide screw.

[0117] Furthermore, the imaging segment may also include: a CMOS image sensor, a 1 / 1.8-inch progressive scan sensor with a resolution of 2048x1536 and 3.15 million pixels.

[0118] Furthermore, the illumination fiber of the endoscope adopts the following scheme: the endoscope probe (i.e., the objective lens section and the relay imaging section) adopts a double-layer metal sleeve with an inner diameter of 6.5 mm and an outer diameter of 7.6 mm. The illumination fiber is embedded between the inner and outer sleeves. The fiber diameter is 50 μm, the numerical aperture (NA) value is 0.65, and the divergence angle is 80 degrees.

[0119] like Figure 12 As shown, a circular diffusing film 57 is further fitted at the fiber optic output port at the top of the probe. The diffusing film increases the uniformity of light and, at the same time, increases the divergence angle of the emitted light.

[0120] In some embodiments, the angle α between the first axis and the second axis is between 90° and 135°, and further, the angle α between the first axis and the second axis is approximately 110° to 135°.

[0121] In some embodiments, the relay imaging segment 20 includes: a first lens group 20A, a second lens group 20B, and a third lens group 20C arranged sequentially; wherein the first lens group 20A and the second lens group 20B are closely adjacent to each other, and a gap is reserved between the second lens group 20B and the third lens group 20C.

[0122] In this embodiment, the lens group uses a rod-shaped cemented lens. See also Figure 4 As shown, the lens group includes lens I 21, lens II 22, lens III 23, lens IV 24, and lens V 25.

[0123] In some embodiments, such as Figure 4 As shown, the imaging segment is provided with the following components from left to right: a front protective glass, a first cemented doublet achromatic lens 31, a biconcave lens 32, a second cemented doublet achromatic lens 33, and a negative meniscus lens 34; wherein, the cemented doublet achromatic lens is used to eliminate chromatic aberration, and the negative meniscus lens is used to correct aberration.

[0124] In some embodiments, the first fixing structure 36 and the second fixing structure 37 are used to position and fix the first cemented doublet achromatic lens 31 and the biconcave lens 32. In some embodiments, the third fixing structure is used to limit and fix the second cemented doublet achromatic lens 33 and the negative meniscus lens 34. In some embodiments, the fixing sleeve 35 is used to accommodate and fix lens structures such as the imaging segment.

[0125] In some embodiments, the field of view (FOV) is 120° diagonally.

[0126] The basic working principle of the endoscope hardware component of this invention is to guide three wavelengths of light to the front end via optical fiber, illuminating the oral cavity wall with different wavelengths of light individually or in combination. The reflected light from the oral cavity wall passes through a relay imaging section in a rigid tube, transmitting the image to the imaging target surface of the CMOS digital camera at the rear end. The CMOS camera then transmits the data to the main control computer via a gigabit network cable for display and data processing.

[0127] The present invention further includes a focusing mechanism to ensure that the system can perform high-definition imaging over a wide range of object distances. The focusing ring is used by the user to adjust the focus in order to adapt to imaging requirements under different object distance conditions.

[0128] After acquiring image data, the system can display real-time images on a screen. In addition, the system has back-end processing software that can input images that require software processing and judgment into a machine learning model for intelligent assisted diagnosis, providing doctors with auxiliary diagnostic information.

[0129] In this embodiment, the curved tube design allows the clinician to hold the front observation window as close as possible to the local oral structure to be observed. This design provides the best user experience for dental clinicians when examining local oral structures of patients, which is beneficial for clinical examination.

[0130] Furthermore, in some embodiments, the endoscope further includes a connector 051, which is used to connect the optical path multiplexing component and the relay imaging segment, so as to input the synthesized light source output from the optical path multiplexing component to the relay imaging segment, and then transmit it to the area to be observed through the objective lens segment.

[0131] In some embodiments, the endoscope is further provided with a focusing ring 052. In some embodiments, a camera mount 053 is provided at the rear end of the imaging segment for mounting a camera 054.

[0132] The effectiveness of the endoscopic tube of this invention was verified by collecting actual operation data from 48 clinicians: The 48 clinicians evaluated the ease of operation (specifically, the ease of angle adjustment was rated as low, medium, and high) and image quality (specifically, the difficulty of distinguishing fine details and subtle differences in tissue structure was rated as low, medium, and high) under different test conditions. The final collected operation data is shown in the table below:

[0133] Table 1 - Test Data Table

[0134]

[0135] Therefore, through experimental verification, the rigid endoscope solution based on three-point limiting proposed in this invention can unexpectedly reduce the difficulty of manual operation for doctors and improve imaging results.

[0136] To further verify the performance of the endoscope of the present invention, Figure 1 Taking the structure shown as an example, the calculation is as follows: In this example, the length of the objective lens section L1 of the endoscope is 1.0cm, the length of the relay imaging section L2 is 7cm, the width of the objective lens and the relay imaging section (i.e., the inner diameter of the tube) is 0.65cm, the outer diameter of the tube is 0.8cm, and the angle between the objective lens section and the relay imaging section is 110°.

[0137] like Figure 6 This is a wave aberration diagram. Wave aberration is the optical path difference between the actual wavefront and the ideal wavefront. It is an important concept in optical systems, used to describe the effect of optical systems on the propagation of light. Figure 6 The x-axis represents the field of view, and the y-axis represents the root mean square wavefront aberration. D1, D2, D3, and D4 represent the polynomial aberration and the root mean square wavefront aberrations for blue light (0.486 nm), green light (0.586 nm), and red light (0.656 nm), respectively. Figure 6 It can be seen that the maximum wavefront aberration of the endoscope is less than 1 / 10λ, which is much smaller than the conventional wavefront aberration tolerance (1 / 4λ).

[0138] In an aberration-free optical system, the light-gathering ratio of the imaging plane (the light-gathering intensity within the Airy disk) is taken as 100%. In an aberration-prone optical system, this ratio is called the "Strehl Ratio (SR value)". An optical system with a higher SR value is closer to an aberration-free optical system. A Strehl ratio of 0.8 is generally considered the diffraction limit; a Strehl ratio below 0.8 does not meet the performance requirements of an objective lens. In general observation, if the Strehl ratio exceeds 0.95, its performance can be considered comparable to that of an aberration-free lens.

[0139] Through simulation calculations using the optical simulation software ZEMAX, the SR values ​​of the endoscope of this invention are 0.970, 0.933, and 0.900 in the central field of view, 0.707 field of view, and full field of view, respectively. That is, the SR values ​​of different fields of view are all above 0.9, indicating small aberrations.

[0140] In a given lens design, field curvature is controlled to within 0.2mm, which is a relatively small value. This indicates that the lens can maintain high image quality during imaging, because a smaller field curvature means smaller aberrations, thereby improving image sharpness and accuracy.

[0141] Figure 7 This is a schematic diagram of field curvature / distortion, where T represents meridional field curvature and S represents sagittal field curvature; from Figure 7 As can be seen, the field curvature of the endoscope in this embodiment is controlled within 0.1 mm. T1, T2, and T3 represent the meridional field curvatures of blue light (wavelength 0.486 nm), green light (wavelength 0.586 nm), and red light (wavelength 0.656 nm), respectively. S1, S2, and S3 represent the sagittal field curvatures of blue light (wavelength 0.486 nm), green light (wavelength 0.586 nm), and red light (wavelength 0.656 nm), respectively.

[0142] Distortion control: Maximum distortion reaches -50%. The negative sign indicates that the direction of distortion is opposite to the normal state, meaning the lens produces negative distortion. Negative distortion can produce special visual effects in certain situations, such as helping to widen the field of view and make the captured image wider. However, distortion is a factor that needs to be balanced; excessive distortion can lead to image distortion and affect the realism of the vision. These indicators show that this endoscope design has achieved excellent results in application, controlling field curvature to ensure image sharpness while achieving the required wide field of view through negative distortion.

[0143] Figure 8 The relationship between the percentage of system distortion and the viewing angle is shown. Figure 9The diagram shows the on-axis lateral aberration range of the endoscope's optical system from -0.08 mm to +0.12 mm. The range of on-axis lateral aberration is a crucial parameter in optical systems, representing the focusing differences of different wavelengths of light at different heights. The axial chromatic aberration results will show the results for different wavelengths and heights. Specifically, A1, A2, and A3 represent the on-axis lateral aberrations for blue light (wavelength 0.486 nm), green light (wavelength 0.586 nm), and red light (wavelength 0.656 nm), respectively. The range of on-axis lateral aberration is typically set to ±0.2 mm. This range is determined based on the design requirements of the optical system and the desired image quality. If the on-axis lateral aberration exceeds this range, it indicates that the image quality of the optical system may not meet the design requirements, necessitating optimization and adjustment. Conversely, Figure 9 This indicates that the lateral aberration on the optical system of the present invention is less than a set range, resulting in higher imaging quality.

[0144] Figures 10a-10h These are photographs of the labial mucosa observed using the endoscope in this example. The area in the center of the frame is the area the doctor needs to focus on, and the luminous area is water on the surface of the oral mucosa, which creates a specular reflection during observation. The distribution of capillaries (i.e., the dark stripes in the image) can be clearly observed in the above image, demonstrating that the endoscope in this embodiment helps doctors distinguish fine details and subtle differences in tissue structure. Furthermore, even in the confined and sensitive area of ​​the gums, the doctor can easily adjust the observation angle using the three-point-limited endoscope to obtain multiple clear photographs of the sensitive area.

[0145] Object distance refers to the distance from an object (such as the skin of the mouth) to the optical center of a lens (such as the optical center of the first lens). To verify the imaging effect of the endoscope proposed in this invention, the imaging sharpness (using object-side resolution and object-side pixels) at different object distances is calculated below. Object height refers to the height of the object relative to the observer or imaging system in the optical system. Image height refers to the height of the image formed by the imaging system (such as a lens) on the imaging plane. Image-side resolution refers to the minimum distance between two image points that the lens can resolve. Object-side resolution refers to the minimum distance between two object points that can be resolved. An object-side pixel is the physical size of the object represented by one pixel on the imaging plane, measured in μm. When the object distance is -5mm...

[0146] Table 2-1

[0147]

[0148] Table 2-2

[0149]

[0150] Table 2-3

[0151]

[0152] When the object distance is -8mm.

[0153] Table 2-4

[0154]

[0155] Table 2-5

[0156]

[0157] Table 2-6

[0158]

[0159] When the object distance is -10mm.

[0160] Table 2-7

[0161]

[0162] Table 2-8

[0163]

[0164] Table 2-9

[0165]

[0166] Tables 2-1 to 2-9 show that at different locations in the oral cavity, when the probe is 5mm to 10mm away from the target, the imaging is clear and...

[0167] Example 2

[0168] The applicant noted that when multiple optical paths are multiplexed, light is particularly prone to loss during transmission, which places higher demands on the light source supply components. For example, if the light source supply components continuously provide high-power light, on the one hand, it easily leads to component heating, requiring higher requirements for heat dissipation design; on the other hand, the increased loss also further increases the operating cost of the device. To address this, the present invention provides an optical path multiplexing device that controls the divergence angle of the incident light source and the loss generated during light transmission, thereby improving the utilization rate of the light source. Correspondingly, see [link to relevant documentation]. Figure 13b The present invention provides an optical path multiplexing device, comprising:

[0169] A first channel for introducing a first light source 01 is provided in the first channel, and a first guide part 51 is provided in the first channel. The first guide part 51 is used to guide the first light source with a first divergence angle into a first parallel light.

[0170] A second channel is provided for introducing the second light source 02, and the second channel is intersecting with the first channel. A second guide part 52 is provided in the second channel. The second guide part 52 is used to guide the second light source with a second divergence angle into a second parallel light. A dichroic mirror 55 is provided at the output end of the second channel. The first parallel light and the second parallel light are converged into at least one mixed parallel light by the dichroic mirror 55. For example, the angle between the mirror surface of the dichroic mirror 55 and the axis of the first channel (or the axis of the second channel) is approximately 45°.

[0171] A third channel is provided for introducing the third light source 03, and the third channel is arranged parallel or approximately parallel to the second channel. A third guide 53 is provided in the third channel. The third guide is used to convert the third light source with a third divergence angle into a third parallel light. A semi-reflective mirror 56 is correspondingly provided at the output end of the third channel. The third parallel light and the mixed parallel light are converged into at least one total light source (also referred to as: mixed beam) by the semi-reflective mirror 56. An enhancing focusing component 58 is provided along the transmission direction of the total light source to focus the total light source. The enhancing focusing component 58 includes:

[0172] (i) A first focusing component 58A, which is used to focus the total light source step by step for the first time; wherein, the first focusing component 58A includes: a first convex-concave lens 581, a second convex-concave lens 582 and a plano-concave lens 583 arranged sequentially along the transmission direction of the total light source; wherein, the first convex surface of the first convex-concave lens 581 and the second convex surface of the second convex-concave lens 582 are both arranged towards the direction of incidence of the total light source, and the third concave surface of the plano-concave lens 583 is arranged opposite to the second concave surface of the second convex-concave lens 582;

[0173] For example, in some embodiments, the thickness of the first convex-concave lens 581, the second convex-concave lens 582, and the plano-concave lens 583 gradually increases, while their diameters gradually decrease. For example, in some embodiments, the dichroic mirror 55 and the semi-reflective mirror 56 are arranged parallel or approximately parallel to each other. See also... Figure 13d As shown, the light spot of the total light source is gradually reduced after being processed by the first convex-concave lens 581, the second convex-concave lens 582, and the plano-concave lens 583.

[0174] (ii) A second focusing component 58B, which expands the divergence angle of the total light source and then focuses the total light source a second time; wherein the second focusing component 58B includes: a first biconvex lens 584 and a second biconvex lens 585 arranged sequentially along the transmission direction of the total light source, wherein the first biconvex lens 584 has a third convex surface 584a and a fourth convex surface 584b, and the radius of curvature of the third convex surface is greater than the radius of curvature of the fourth convex surface 584b; the second biconvex lens 585 has a fifth convex surface 585a and a sixth convex surface 585b, and the radius of curvature of the fifth convex surface is smaller than the radius of curvature of the sixth convex surface 585b.

[0175] In an exemplary embodiment, the third and fifth convex surfaces are positioned facing the direction in which the main light source enters. See also Figure 13d As shown, in some embodiments, the thickness of the first biconvex lens 584 is greater than the thickness of the second biconvex lens 585.

[0176] In some embodiments, the device further includes an optical fiber, wherein the input end of the optical fiber is disposed toward the output end of the second focusing assembly 58B, and the diameter of the input end of the optical fiber is smaller than the diameter of the second biconvex lens 585. See also Figure 13d As shown, after the light spot of the total light source is reduced by the first focusing component 58A, it will first be magnified to a certain extent by the first biconvex lens 584, and then the light spot of the total light source will be reduced to a size smaller than the diameter of the optical fiber by the second biconvex lens 585, so as to guide the total light source to be effectively transferred into the optical fiber.

[0177] In some embodiments, the light-blocking plate 586 is further included, the light-blocking plate 586 having a first inner hole, the light-blocking plate being disposed between the first focusing component 58A and the second focusing component 58B, and the first radius of the first inner hole satisfying the following setting rule: the first radius is smaller than the diameter of the plano-concave lens 583, and the first radius is smaller than the diameter of the first biconvex lens 584.

[0178] For example, in some embodiments, the first radius of the first inner hole is approximately 8 mm.

[0179] See Figure 13dAs shown, the enhanced focusing component provided in this exemplary embodiment is designed with several coordinated focusing stages for the mixed beam: 1) using a biconvex-concave lens in conjunction with a plano-concave lens 583 to progressively reduce the divergence angle of the total light source (i.e., performing the first focusing operation); 2) filtering edge stray light from the total light source after the first focusing (i.e., filtering stray light at the edges of the mixed beam through a first light-blocking plate); 3) spreading the divergence angle of the filtered mixed beam and performing a second focusing. In other words, this embodiment focuses on enhanced focusing design at the fiber optic inlet to significantly reduce the loss generated during beam mixing and transmission. Furthermore, experimental verification has shown that this angle-reduction-diffusion-reduction transmission mode effectively reduces the spot size of the mixed light, making it smaller than the size of the fiber optic inlet, while mitigating the loss problem during spot reduction.

[0180] In some embodiments, the diameter of the second convex-concave lens 582 is smaller than the diameter of the first convex-concave lens 581.

[0181] In some embodiments, the thickness of the second convex-concave lens 582 is greater than the thickness of the first convex-concave lens 581.

[0182] In some embodiments, the first guide portion 51 includes: a first guide lens 511 arranged sequentially along the transmission direction of the first light source, and the first guide lens 511 having a first guide convex surface 511a and a first conical surface 511b; a first plano-convex lens 512, and the plane of the first plano-convex lens 512 is disposed facing the first conical surface.

[0183] Furthermore, in some embodiments, the first guide portion 51 further includes a third light-blocking plate (not shown in the figure), which is disposed between the corresponding two lenses, and the third light-blocking plate has a third inner hole so that light in the central region of the first light source can pass through the third inner hole, while other stray light can be blocked by the third light-blocking plate.

[0184] In some embodiments, see Figure 11 As shown, the second guide portion 52 includes: a second guide lens 521 arranged sequentially along the transmission direction of the second light source, and the second guide lens 521 having a second guide convex surface 521a and a second conical surface 521b; a second plano-convex lens 522, and the plane of the second plano-convex lens 522 is arranged facing the second conical surface.

[0185] Furthermore, in some embodiments, the second guide portion 52 further includes a fourth light-blocking plate, which has a fourth inner hole so that light in the central region of the second light source can pass through the fourth inner hole, while other stray light can be blocked by the fourth light-blocking plate.

[0186] In some embodiments, the third guide portion 53 includes: a third guide lens 531 arranged sequentially along the transmission direction of the third light source, wherein the first guide lens 531 has a third guide convex surface 531a and a third conical surface 531b; and a third plano-convex lens 532, wherein the plane of the third plano-convex lens 532 is disposed facing the third conical surface.

[0187] Furthermore, in some embodiments, the second guide portion 52 further includes a fifth light-blocking plate, which has a fifth inner hole so that light in the central region of the third light source can pass through the fifth inner hole, while other stray light can be blocked by the fifth light-blocking plate.

[0188] In some embodiments, the system further includes a second light-blocking plate 59, which has a second inner hole and is disposed between the semi-reflective lens 56 and the first focusing assembly 58A. In this embodiment, the second light-blocking plate enables preliminary filtering of stray light from the initially mixed total light source.

[0189] In some embodiments, the light-blocking plate is a light barrier.

[0190] It is worth noting that stray light filtering is performed on three core stages: the initial incidence stage of a single light source (i.e., when the light source passes through the guiding lens), the initial mixing stage of multiple single light sources (i.e., after being mixed into a total light source by a semi-reflective lens), and the stage after the total light source is gradually focused. In other words, this embodiment selects three core locations to set up light-blocking plates to filter stray light from different positions and transmission stages, thereby improving the clarity and resolution of the final image through the limited use of light-blocking plates. See also Figures 15-18 As shown, the light spot of the final mixed light source can be reduced with high quality and its loss is relatively small.

[0191] Specifically, to verify that the optical path multiplexing device proposed in this invention can effectively focus multiple light sources and reduce the loss of light sources during transmission, this invention further... Figures 13a-13d The optical path multiplexing device shown was tested for optical transmission. Figure 15 , Figure 16 The diagrams showing the light spot sizes of the main light source at positions P1 and P2 are shown in sequence. Figure 17 , Figure 18The power of the total light source at position P1 and position P2 is shown in sequence. Tests show that the optical path multiplexing component proposed in this invention can improve the effective utilization rate between the initial total light source (i.e., the mixed beam obtained by initially mixing the three light sources at position P1) and the final total light source (i.e., the mixed beam obtained after the initial total light source has been reduced in size by the strengthening and focusing component) to at least 77.30%.

[0192] In some embodiments, the wavelength range of the first light source includes 492nm-577nm, and the wavelength range of the second light source includes 380nm-455nm. In some embodiments, the wavelength range of the third light source includes 400nm-770nm. Alternatively, in other embodiments, the wavelength range of the third light source includes 620nm-770nm. In some embodiments, the first guide portion, the second guide portion, and the third guide portion may be collimating lenses.

[0193] To more clearly illustrate the technical solution adopted in this invention, the workflow of this invention will be explained exemplarily below through combinations of different light sources. See also Figures 11-13d As shown, the present invention also provides an optical path multiplexing component that provides light sources of different intensities to the endoscope.

[0194] The first exemplary embodiment will be described using white light as an example: Figure 11 As shown, the optical path multiplexing component includes a first light source, a second light source, and a third light source with different wavelengths. The working process is explained below using green light, violet light, and white light as examples (the first, second, and third light sources, respectively): Green light passes through a collimating lens and enters a dichroic mirror 55. The dichroic mirror has the characteristic of allowing long wavelengths (such as green light of approximately 560nm) to pass through and short wavelengths (such as violet light of approximately 410nm) to be reflected and transmitted parallel to each other, entering a semi-reflective mirror 56.

[0195] The characteristic of a semi-reflective mirror is that, within the visible light band, half of the transmitted light is transmitted and the other half is lost (absorbed by the material on the inner surface of the cavity), and the reflected light is also half reflected and half lost. When green light passes through the semi-reflective mirror, half of its energy is lost, and it enters the coupling lens 54, which reduces the light spot, making the incident angle of the light less than the numerical aperture NA value of the optical fiber, thus transmitting the light most effectively.

[0196] The violet light passes through the collimating lens and enters the dichroic mirror 55. The dichroic mirror's characteristic is that longer wavelengths pass through while shorter wavelengths are reflected. The violet light is reflected at a 90-degree angle and enters the semi-reflective mirror. The semi-reflective mirror's characteristic is that within the visible light range, half of the transmitted light is transmitted and half is lost (absorbed by the material on the inner surface of the cavity), and the reflected light is also half reflected and half lost. The violet light, having lost half its energy, passes through the semi-reflective mirror and enters the coupling lens 54, where the light spot is reduced, before being transmitted into the optical fiber.

[0197] White light passes through a collimating lens and enters a semi-reflective mirror 56. The characteristic of a semi-reflective mirror is that, within the visible light spectrum, half of the transmitted light is transmitted and the other half is lost (absorbed by the material on the inner surface of the cavity), and the reflected light is also half reflected and half lost. After being reflected by the semi-reflective mirror, the white light loses half of its energy and enters the coupling lens, where the light spot is reduced before it is transmitted into the optical fiber.

[0198] In some embodiments, the dichroic mirror 55 and the semi-reflective mirror 56 are the same size, such as 20mm × 30mm, with a thickness of approximately 2mm. In some embodiments, the inner diameter of the aperture in the collimating lens is approximately 17.2mm, which mainly serves to block stray light. In some embodiments, the parameters of the two lenses before and after the collimating lens are: thickness 10.9mm, diameter 20mm; thickness 8mm, diameter 20mm; the aperture is centered with an interval of approximately 1mm between them. In some real-world scenarios, the equivalent distance between the dichroic mirror 55 and the collimating lens is approximately 21.86mm, and can also be set to 22mm. In some embodiments, the equivalent distance between the semi-reflective mirror 56 and the collimating lens is approximately 53.73mm, and can also be set to approximately 54mm. In some embodiments, the strengthening and focusing assembly (or coupling lens assembly) has five lenses arranged sequentially along the light transmission direction, and the thicknesses of each lens are approximately 6.5mm, 6.5mm, 6.6mm, 6.5mm, and 4.67mm.

[0199] It is understood that the parameters described in the above embodiments are preferred settings, and the optical path composite component provided by the present invention can also be adapted to the above parameters in combination with actual application conditions.

[0200] Further explanation: In the coupling lens group, the light emitted by the LED light source, after passing through the collimating lens, becomes parallel light, and then passes through a dichroic mirror or a semi-reflective mirror. The light then passes through the converging lens group and couples into the optical fiber. Even further explanation: After passing through the collimating lens, the light spot diameter is 6mm; after passing through the coupling lens group, the light spot diameter is 4mm. The incident angle is smaller than the numerical aperture of the optical fiber, thus most effectively directing the light into the fiber.

[0201] In some embodiments, the wavelength range of the first light source includes 492nm-577nm; the wavelength range of the second light source includes 380nm-455nm. In some embodiments, the wavelength range of the third light source includes 400nm-770nm. In this embodiment, the third light source is white light.

[0202] In this exemplary embodiment, the first and second light sources are combined using a dichroic mirror, while the third light source is treated using a semi-reflective mirror. Preferably, the first light source is supplied with a green LED chip (492nm to 577nm), the second light source with a blue LED chip (380nm to 455nm), and the third light source with a white LED chip (400nm to 770nm).

[0203] To more clearly illustrate the technical solution and application characteristics of this invention, the effects of different wavelengths of light are explained below: The specific spectrum of 410nm blue light mostly reaches the epidermis, 560nm green light can reach the microcirculation layer, and 620nm red light can reach the dermis. Superficial capillaries appear brownish-brown, while the dendritic vessels beneath the mucosal surface appear dark green. The combined light from the first and second light sources can display the morphology of dendritic capillaries 1mm to 2mm beneath the mucosal surface, serving as a basis for judging mucosal lesions.

[0204] In some embodiments, the third light source can be used alone, while the first and second light sources are turned off. The white light in the third light source is turned on to display the overall appearance of the mucosa. The white light is close to natural light, with a color rendering index (CRI) > 90, consistent with the results observed by the naked eye. This embodiment achieves at least the following advantages: the entire lens assembly is fixedly installed with no moving parts, simplifying the mechanical structure, making it easy to use and maintain, and reducing the likelihood of malfunctions.

[0205] Second exemplary embodiment: To optimize the optical power loss problem in the first exemplary embodiment, the present invention further optimizes the composite optical path. The first and second light sources are combined using a dichroic mirror, and the third light source is also combined using a dichroic mirror. The first light source is supplied with a green LED chip (492nm to 577nm), the second light source with a blue LED chip (380nm to 455nm), and the third light source with a red LED chip (620nm to 770nm). Similarly, the entire lens assembly is fixedly installed with no moving parts, simplifying the mechanical structure, making it easy to use and maintain, and reducing the likelihood of failure; moreover, the optical power loss of the entire system is reduced to approximately 40%.

[0206] Third exemplary embodiment: An illumination intensity of 300,000 lux at the output port of the mirror probe is sufficient for the application scenario. However, in some scenarios with extremely high losses, such as a 50% loss of optical power due to a semi-reflective mirror, a 20% loss due to fiber refraction, and a 10% loss due to the probe's astigmatism film, the total optical power loss of the entire fiber optic transmission system may reach 80%. In such cases, the luminous intensity of the LED light source needs to be 1,500,000 lux to meet the system design requirements. To reduce optical power loss, a reflector can be installed in the structure, fitted into a beveled slot with a spring. Pressing it once fixes the reflector in the optical channel; pressing it a second time releases the reflector, allowing it to move laterally away from the optical channel. When green, purple, or a mixture of green and purple are needed, the reflector is in the released position, allowing monochromatic light or the mixed green and purple light to enter the coupling lens group through the dichroic mirror. When white light is needed, the reflector is in the pressed position, allowing white light to enter the coupling lens group through the reflector. Adding a mechanical push-to-release switch, along with a reflector, can reduce the optical power loss of the entire system. The luminous intensity of the LED light source is only 400,000 lux to meet the system requirements.

[0207] Figures 14a-14d These are schematic diagrams of the spectra of light at different wavelengths. Figure 14e This is a schematic diagram of the emission spectrum of a white light chip using a combination of R, G, and B primary colors LEDs; Figure 14f This is the light distribution curve of the LED. The horizontal and vertical axes on the left are the relative intensity of the light, and the corresponding radian data are the angle values ​​of the LED illumination. The horizontal axis on the right is the angle value of the LED illumination angle. Figure 14f The dashed line in the diagram shows that when the relative intensity of the illumination is 50%, the single-sided illumination angle is 60°, and the overall conical illumination angle of the beam is 120 degrees. For the RGB tri-color LED mixed white light spectrum, the relative intensity in the 470nm to 500nm band is below 20%, affecting the Color Rendering Index (CRI) value, which is less than 70. In contrast, the white light LED spectrum has an overall luminous intensity greater than 45% and a CRI value greater than 90. The light distribution curve refers to the illumination angle of the LED emission. When the relative intensity of the illumination is 50%, the single-sided illumination angle is 60 degrees, and the overall conical illumination angle is 120 degrees. This LED illumination angle is used in the design of the collimating lens group. The emitted light from the LED is collected and converged into parallel light, forming the first, second, and third optical paths.

[0208] The embodiments of the present invention are described below with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. An optical path multiplexing device, characterized in that, include: A first channel for introducing a first light source (01) is provided in the first channel, and a first guide part (51) is provided in the first channel. The first guide part (51) is used to guide the first light source with a first divergence angle to convert it into a first parallel light. A second channel is provided for introducing a second light source (02), and the second channel is intersected with the first channel. A second guide (52) is provided in the second channel. The second guide (52) is used to guide the second light source with a second divergence angle to convert it into a second parallel light. A dichroic mirror (55) is provided at the output end of the second channel. The first parallel light and the second parallel light are converged into at least one mixed parallel light by the dichroic mirror (55). A third channel for introducing a third light source (03) is provided, and the third channel is arranged parallel or approximately parallel to the second channel. A third guide (53) is provided in the third channel, and the third guide is used to convert the third light source with a third divergence angle into a third parallel light. A semi-reflective mirror (56) is provided at the output end of the third channel, and the third parallel light and the mixed parallel light are converged into at least one total light source by the semi-reflective mirror (56). An enhancement focusing component for focusing the total light source is provided along the transmission direction of the total light source, and the enhancement focusing component (58) includes: (i) A first focusing component (58A), the first focusing component (58A) being used to perform a first focusing of the total light source in stages; wherein, the first focusing component (58A) includes: A first convex-concave lens (581), a second convex-concave lens (582), and a plano-concave lens (583) are arranged sequentially along the transmission direction; wherein, the first convex surface of the first convex-concave lens (581) and the second convex surface of the second convex-concave lens (582) are both arranged toward the direction of the incident light source, and the third concave surface of the plano-concave lens (583) is arranged opposite to the second concave surface of the second convex-concave lens (582); (ii) A second focusing component (58B) for expanding the divergence angle of the total light source and subsequently focusing the total light source a second time; wherein the second focusing component (58B) includes a first biconvex lens (584) and a second biconvex lens (585) arranged sequentially along the transmission direction, wherein the first biconvex lens (584) has a third convex surface (584a) and a fourth convex surface (584b), and the radius of curvature of the third convex surface is greater than the radius of curvature of the fourth convex surface (584b), and the second biconvex lens (585) has a fifth convex surface (585a) and a sixth convex surface (585b), and the radius of curvature of the fifth convex surface is smaller than the radius of curvature of the sixth convex surface (585b).

2. The optical path multiplexing device according to claim 1, characterized in that, Also includes: A first light-blocking plate (586) is provided with a first inner hole. The first light-blocking plate is disposed between the first gathering component (58A) and the second gathering component (58B). The first radius of the first inner hole satisfies the following setting rule: the first radius is smaller than the diameter of the plano-concave lens (583) and the first radius is smaller than the diameter of the first biconvex lens (584).

3. The optical path multiplexing device according to claim 1, characterized in that, Also includes: An optical fiber, wherein the input end of the optical fiber is disposed toward the output end of the second focusing component (58B), and the diameter of the input end of the optical fiber is smaller than the diameter of the second biconvex lens (585).

4. The optical path multiplexing device according to claim 1, characterized in that, The diameter of the second convex-concave lens (582) is smaller than the diameter of the first convex-concave lens (581); and / or, the thickness of the second convex-concave lens (582) is greater than the thickness of the first convex-concave lens (581).

5. The optical path multiplexing device according to claim 1, characterized in that, The first guide section (51) includes: A first guide lens (511) is arranged sequentially along the transmission direction of the first light source, and the first guide lens (511) has a first guide convex surface (511a) and a first conical surface (511b). A first plano-convex lens (512) is provided, and the plane of the first plano-convex lens (512) is disposed facing the first conical surface.

6. The optical path multiplexing device according to claim 1, characterized in that, The second guide section (52) includes: A second guide lens (521) is arranged sequentially along the transmission direction of the second light source, and the second guide lens (521) has a second guide convex surface (521a) and a second conical surface (521b); The second plano-convex lens (522) is provided with its plane facing the second conical surface.

7. The optical path multiplexing device according to claim 1, characterized in that, The third guide section (53) includes: A third guide lens (531) is arranged sequentially along the transmission direction of the third light source, and the first guide lens (531) has a third guide convex surface (531a) and a third conical surface (531b); A third plano-convex lens (532) is provided, and the plane of the third plano-convex lens (532) is disposed facing the third conical surface.

8. The optical path multiplexing device according to claim 1, characterized in that, Also includes: The second light-blocking plate has a second inner hole and is disposed between the semi-reflective lens (56) and the first focusing component (58A).

9. The optical path multiplexing device according to claim 1, characterized in that, The wavelength range of the first light source is 492nm-577nm, and the wavelength range of the second light source is 380nm-455nm.

10. An optical path multiplexing device according to claim 9, characterized in that, The wavelength range of the third light source is 400nm-770nm; or the wavelength range of the third light source is 620nm-770nm.

Images