Imaging device

Abstract

The invention relates to the technical field of endoscopes, in particular to an imaging device which comprises a tube used for transmitting images, and the tube is internally provided with an objective lens section with a first axis and the length of 0.5-2.5 cm; the relay imaging section is provided with a second axis, the intersection angle alpha between the first axis and the second axis ranges from 90 degrees to 135 degrees, and the length of the relay imaging section ranges from 3 cm to 10 cm; a reflecting lens is arranged at the position where the first axis and the second axis intersect, and the reflecting lens reflects an image output by the objective lens section and guides the reflected image to be input into the relay imaging section; the tube wall of the tube is made of a hard material corresponding to the switching position of the objective lens section and the relay imaging section; the problems that an existing endoscope has observation dead angles and is low in imaging definition are solved.

Description

Technical Field

[0001] This invention relates to the field of endoscopy technology, and more specifically to an imaging device. Background Technology

[0002] Oral potentially malignant disorders (OPMDs) refer to oral mucosal diseases or abnormalities that may develop into oral squamous cell carcinoma (OSCC). The average malignancy rate of OPMDs is approximately 7.9%. OPMDs typically progress through multiple stages, from normal epithelial hyperplasia to mild, moderate, and severe dysplasia, eventually developing into OSCC. Studies have shown that the more severe the epithelial dysplasia, the greater the risk of OPMDs transforming into OSCC. Because OPMDs occur in the maxillofacial region, if they become cancerous, they can lead to severe deformities and disabilities that are difficult to correct. This not only affects the patient's physical and mental health and quality of life but also places a heavy burden on society and the healthcare system.

[0003] Therefore, it is very important and urgent to find a highly sensitive and specific early cancer auxiliary diagnostic technology that can accurately determine the status of OPMDs and select the best treatment plan accordingly.

[0004] Angiogenesis is a key marker in the development and progression of cancer. As mucosal malignancy progresses, the submucosal capillary network also undergoes corresponding changes. Narrow-band imaging (NBI) is an endoscopic technique that enhances the visualization of superficial capillaries and submucosal vessels using a specific wavelength of light. Endoscopy based on NBI technology has been widely used for early cancer screening of epithelial tumors in the gastrointestinal tract and other areas, demonstrating good auxiliary diagnostic effects.

[0005] However, the NBI endoscopic instruments currently used in clinical practice mainly fall into two categories:

[0006] One type is the flexible endoscope (such as the Olympus Electronic Nasopharyngoscope ENF-VT3), whose probe is made entirely or partially of a flexible tube.

[0007] For example, patent application CN102282496A discloses an optical system for an endoscope and an endoscope, which includes: a front end portion, and a front tube and a rear tube sequentially arranged from the top side of the front end portion. The front tube and the rear tube are configured to be able to rotate independently of each other in the circumferential direction relative to the curved portion. The operator can bend the curved portion by operating a handle.

[0008] Another type is rigid endoscopes. For example, Chinese patent application CN106461929A discloses an endoscope system that includes an objective lens optical system, an optical path segmentation unit that divides the subject image obtained by the objective lens optical system into two optical images with different focal points, an imaging element that acquires the optical images, and an image synthesis processing unit that selects the image with relatively high contrast from the two acquired optical images in a specified area to generate a composite image.

[0009] However, the above-mentioned traditional flexible or rigid endoscope designs will have many problems when applied to oral examinations:

[0010] 1) It is difficult to adjust the angle, which makes it inconvenient for doctors to flexibly adjust the observation angle and observation area inside the oral cavity (blind spots are unavoidable), and such adjustment activities inside the oral cavity will also increase the patient's discomfort.

[0011] 2) The shallow depth of field results in low image clarity, which is not conducive to doctors' clear and complete observation of local oral structures;

[0012] 3) The medical flexible endoscope uses a fiber optic imaging probe, requiring two operators to work together when performing oral cavity exploration. One operator needs to hold the probe with one hand and the handle with the other, while the other operator needs to assist in opening the patient's mouth, which presents inconvenience. Summary of the Invention

[0013] The purpose of this invention is to provide an imaging device for an endoscope that partially solves or alleviates the above-mentioned shortcomings in the prior art, enabling flexible adjustment of the observation angle, improving imaging clarity, and reducing discomfort to the patient during the observation process.

[0014] To solve the aforementioned technical problems, the present invention specifically adopts the following technical solution:

[0015] A first aspect of the present invention provides an imaging device comprising: a tube for transmitting an image, the tube comprising:

[0016] An objective lens section having a first axis, the length of which is 0.5-2.5 cm;

[0017] The relay lens segment has a second axis, the angle α between the first axis and the second axis is 90°-135°, and the length of the relay imaging segment is 3-10cm;

[0018] A reflective lens is provided at the intersection of the first axis and the second axis. The reflective lens reflects the image output by the objective lens segment and guides the reflected image to the relay imaging segment.

[0019] The tube wall, corresponding to the junction between the objective lens section and the relay imaging section, is made of a rigid material.

[0020] In some embodiments, the width of the objective lens segment is 0.3-1.0 cm.

[0021] In some embodiments, the width of the relay imaging segment is 0.3-1.0 cm.

[0022] In some embodiments, the included angle α is 110°-135°.

[0023] In some embodiments, the relay imaging segment includes at least one set of cemented lenses.

[0024] In some embodiments, the cemented lens is a rod-shaped cemented lens.

[0025] 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 in sequence from its input end to its output end, and the direction from the input end to the output end is the direction in which the image is transmitted within the objective lens segment.

[0026] In some embodiments, a first aperture is provided between the negative power lens and the positive power lens, and a second aperture is provided between the positive power lens and the cemented doublet achromatic lens.

[0027] In some embodiments, the rigid material includes one or more of the following: metal, plastic, metal-plastic composite, ceramic, and opaque glass.

[0028] In some embodiments, at least one optical fiber is disposed on the inner side of the tube wall, the optical fiber being used to transmit the light source.

[0029] The present invention also provides an endoscope, comprising:

[0030] A tube for transmitting images, wherein the following components are sequentially arranged inside the tube:

[0031] An objective lens section having a first axis, the length of which is 0.5-2.5 cm;

[0032] The relay imaging segment has a second axis, the angle α between the first axis and the second axis is between 90° and 135°, and the length of the relay imaging segment is 3-10cm;

[0033] A reflective lens is provided at the intersection of the first axis and the second axis. The reflective lens reflects the image output by the objective lens segment and guides the reflected image to the relay imaging segment.

[0034] The tube wall at the junction of the objective lens section and the relay imaging section is made of a rigid material;

[0035] An imaging segment is connected to the output end of the tube.

[0036] In some embodiments, the imaging segment is provided with the following components sequentially from its first end to its second end: a first cemented doublet achromatic lens, a biconcave lens, a second cemented doublet achromatic lens, and a negative meniscus lens; wherein the first cemented doublet achromatic lens, the second cemented doublet achromatic lens, and the biconcave lens cooperate to eliminate chromatic aberration in the image, and the negative meniscus lens is used to correct aberrations in the image.

[0037] In some embodiments, the relay imaging segment is further connected to a light source assembly, which provides 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.

[0038] In some embodiments, the width of the objective lens segment is 0.3-1.0 cm.

[0039] In some embodiments, the width of the relay imaging segment is 0.3-1.0 cm.

[0040] In some embodiments, the included angle α is 110°-135°.

[0041] In some embodiments, the system further includes a protective film for covering at least a portion of the objective lens section and the relay imaging section.

[0042] In some embodiments, the relay imaging segment includes at least one set of cemented lenses.

[0043] In some embodiments, the rigid material is made of one or more of the following materials: metal, plastic, metal-plastic composite, ceramic, and opaque glass.

[0044] In some embodiments, the tube includes a first sleeve, a second sleeve is fitted inside the first sleeve, and the second sleeve is used to fix the lenses in the objective lens section and the relay imaging section.

[0045] Unlike ear, nose, or other general surgical examinations, oral examinations have the following unique characteristics:

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] Currently, oral examinations, which involve adjusting different viewing angles, can often only be performed using a flexible endoscope.

[0052] 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.

[0053] 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. Attached Figure Description

[0054] 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.

[0055] Figure 1 This is a schematic cross-sectional view of the endoscope in an exemplary embodiment of the present invention;

[0056] Figure 2 This is a schematic diagram of the imaging segment in an exemplary embodiment of the present invention;

[0057] Figure 3 This is a partial structural schematic diagram of the relay imaging segment in an exemplary embodiment of the present invention;

[0058] Figure 4 This is a partial structural diagram of the imaging segment in an exemplary embodiment of the present invention;

[0059] Figure 5 This is a schematic diagram of an endoscope structure in an exemplary embodiment of the present invention.

[0060] Figure 6 Waveform aberration diagram of an endoscope according to an exemplary embodiment of the present invention;

[0061] Figure 7 This is a schematic diagram of field curvature and distortion of an exemplary embodiment of the present invention;

[0062] Figure 8 This is a schematic diagram of system distortion in an exemplary embodiment of the present invention;

[0063] Figure 9 This is a schematic diagram of on-axis lateral aberration in an exemplary embodiment of the present invention;

[0064] Figure 10a This is a first photograph of the oral mucosal surface observed by an exemplary endoscope of the present invention;

[0065] Figure 10b This is a second photograph of the oral mucosal surface observed by an exemplary endoscope of the present invention;

[0066] Figure 10c This is a third photograph of the oral mucosa surface observed by an exemplary endoscope of the present invention;

[0067] Figure 10d This is a fourth photograph of the oral mucosa surface observed by an exemplary endoscope of the present invention;

[0068] Figure 10e This is a fifth photograph of the oral mucosa surface observed by an exemplary endoscope of the present invention;

[0069] Figure 10f This is a sixth photograph of the oral mucosa surface observed by an exemplary endoscope of the present invention;

[0070] Figure 10g This is the seventh photograph of the oral mucosa surface observed by an exemplary endoscope of the present invention;

[0071] Figure 10hThis is the eighth photograph of the oral mucosa surface observed by an exemplary endoscope of the present invention.

[0072] Figure label:

[0073] 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, and 10B is the first sleeve.

[0074] 20 is the relay imaging segment, 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, 20B is the second lens group, and 20C is the third lens group.

[0075] 30 is the imaging segment, 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 cemented lens, 35 is the fixing sleeve, 36 is the first fixing structure, 37 is the second fixing structure, and 38 is the third fixing structure.

[0076] 40 is a reflecting lens; 51 is a connector; 52 is a focusing ring; 53 is a camera mount; and 54 is a camera. Detailed Implementation

[0077] 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.

[0078] In this document, suffixes such as "module," "part," or "unit" used to denote elements are used only for the purpose of illustrative purposes and have no specific meaning in themselves. Therefore, "module," "part," or "unit" may be used interchangeably.

[0079] In this document, the terms "upper," "lower," "inner," "outer," "front," "rear," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0080] In this document, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" 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 components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0081] In this document, "and / or" includes any and all combinations of one or more of the listed related items.

[0082] In this article, "multiple" means two or more, that is, it includes two, three, four, five, etc.

[0083] 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.

[0084] As used in this specification, the term "about" typically means + / - 5% of the value, more typically + / - 4%, more typically + / - 3%, more typically + / - 2%, even more typically + / - 1%, even more typically + / - 0.5% of the value.

[0085] In this specification, certain embodiments may be disclosed in a range-bound format. It should be understood that this "range-bound" description is merely for convenience and brevity and should not be construed as a rigid limitation on the disclosed range. Therefore, the description of a range should be considered as having specifically disclosed all possible subranges and the individual numerical values ​​within those ranges. 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 the individual numbers within those ranges, such as 1, 2, 3, 4, 5, and 6. This rule applies regardless of the breadth of the range.

[0086] In this article, a "lens" is a device made according to the laws of light refraction. A lens is a refracting mirror whose refractive surfaces are two spherical surfaces (or a portion of a spherical surface) and a single plane, forming a transparent object. The image it produces can be either a real image or a virtual image.

[0087] In this article, "cemented lens" refers to a lens obtained by cementing two or more lenses together (for example, two lenses cemented together are also called: doublet lens).

[0088] In this article, "semi-transparent and semi-reflective mirror" is also known as a beam splitter, beam splitter, or semi-reflective 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] In fact, for patients who may already have oral diseases (such as oral ulcers), this adjustment process may further damage the oral cavity.

[0093] Example 1

[0094] To address the aforementioned technical problems, this invention proposes a bent rigid tube with a specific angle, i.e., an imaging device, comprising: a tube for transmitting images, wherein the tube includes:

[0095] An objective lens section having a first axis, wherein the length L1 of the objective lens section is 0.5-2.5 cm;

[0096] The relay imaging segment has a second axis, the angle α between the first axis and the second axis is 90-135°, and the length L2 of the relay imaging segment is 3-10cm.

[0097] A reflective lens is provided at the intersection of the first axis and the second axis. The reflective lens reflects the image output by the objective lens segment and guides the reflected image to the relay imaging segment.

[0098] The tube wall, corresponding to the junction between the objective lens section and the relay imaging section, is made of a rigid material.

[0099] like Figure 1 As shown, the length L1 of the objective lens segment refers to the length between the end of the tube (i.e., the end facing the area to be observed) and the bend (for example, objective lens segment L1 can refer to the distance between the lens on the side of the objective lens segment closest to the area to be observed and the lens adjacent to the bend); the length L2 of the relay imaging segment refers to the length between the bend and one end of the adjacent imaging segment (for example, the length of relay imaging segment L2 can refer to the distance between the lenses at the first end and the second end within it).

[0100] The distance between two lenses can refer to the distance between the two surfaces of the two lenses that are furthest apart.

[0101] In this article, the two ends of the "tube" or "segment" along the direction of image transmission are referred to as the first end and the second end, or also as the input end and the output end.

[0102] Preferably, the pipe walls in this embodiment are made of one or more of the following materials: metal, plastic, metal-plastic composite, ceramic, or opaque glass.

[0103] Therefore, in this embodiment, during the process of adjusting the observation angle by inserting the tube into the oral cavity, the angle between its first axis and second axis remains constant.

[0104] "Maintaining a constant" means that the included angle does not change or changes very slightly.

[0105] In some embodiments, at least one set of cemented lenses is provided in the relay imaging section, and therefore it is also referred to as a cemented lens section.

[0106] Unlike traditional techniques that allow for arbitrary angle adjustment, this invention proposes a solution with a fixed bending angle.

[0107] Furthermore, the applicant unexpectedly discovered that this three-point limiting scheme, which coordinates the values ​​at three points (i.e., the included angle, length L1, and length L2) of the tube, the tube head, and the tube end, actually integrates advantages such as convenient adjustment of the observation angle, comprehensiveness of the observation angle, and clarity of observation on rigid endoscopes.

[0108] Furthermore, because this rigid endoscope significantly improves the ease of operation for doctors, it allows them to more easily adjust and find the best viewing angle in the oral cavity, thus effectively avoiding or reducing discomfort for patients during the adjustment process.

[0109] In other words, the endoscope provided in this embodiment coordinates the selection of a limited combination of factors such as the length 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, thereby enabling the endoscope's three-point limiting scheme to meet the observation angle requirements at different positions inside the oral cavity.

[0110] 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.

[0111] 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.

[0112] In some embodiments, the width of the objective lens segment is 0.3-1.0 cm.

[0113] In some embodiments, the width of the relay imaging segment is 0.3-1.0 cm.

[0114] The width of the objective lens section and the relay imaging section refers to the width of the lens within them.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] In this embodiment, the impact of the concave and convex planes inside the oral cavity on the image clarity is further considered. Therefore, by setting the first aperture, the second aperture and each lens in sequence, the incident angle of the optical fiber can be reduced and the depth of focus can be increased, thereby ensuring that each point with a different end distance can be clearly imaged.

[0119] This also makes it easier to distinguish subtle differences in fine details and organizational structure.

[0120] 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.

[0121] Preferably, the depth of focus of the objective lens can be set to approximately 0.5cm-1cm.

[0122] It is worth noting that the rigid endoscope in this invention will also have better optical stability:

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] Furthermore, the present invention also provides a rigid endoscope with a specific bending angle, comprising:

[0129] A tube for transmitting images, the tube comprising:

[0130] An objective lens section having a first axis, the length of which is 0.5-2.5 cm;

[0131] The relay imaging segment has a second axis, the angle α between the first axis and the second axis is between 110° and 135°, and the length of the relay imaging segment is 3-10cm.

[0132] A reflective lens is provided at the intersection of the first axis and the second axis;

[0133] The tube wall at the junction of the objective lens section and the relay imaging section is made of a rigid material;

[0134] An imaging segment is connected to the output end of the tube.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] The technical solution protected by this invention will be specifically described below through an exemplary embodiment:

[0140] See Figures 1-5 As shown, the present invention provides an endoscope.

[0141] Endoscopes include:

[0142] Objective lens section 10, which has a first axis;

[0143] The relay imaging segment 20 has a second axis, and the first axis and the second axis intersect to form an included angle α.

[0144] 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.

[0145] Imaging segment 30;

[0146] 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.

[0147] Objective lens segment 10 includes:

[0148] First lens 11; the first end of the first lens has a flat surface, and the second end has an inwardly recessed concave surface;

[0149] The second lens 12 has a first end facing the second end of the first lens and has a flat surface; the second end of the second lens 12 has an outwardly convex surface.

[0150] A first aperture 13 is provided between the first lens 11 and the second lens 12;

[0151] A third lens 14 is provided, and a second aperture 15 is provided between the third lens 14 and the second lens; a through hole 151 is provided on the second aperture 15, 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 connected to the second lens 12 and the third lens 14 in sequence.

[0152] The fourth lens 16 has a convex surface at its first end; and a locking structure 17 is provided 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.

[0153] An aperture stop is an entity in an optical system that limits the beam of light.

[0154] In some embodiments, the first lens 11 is a negative power lens.

[0155] In some embodiments, the second lens 12 is a positive power lens.

[0156] In some embodiments, the third lens 14 is a cemented doublet achromatic lens.

[0157] In some embodiments, the fourth lens 16 is a plano-convex lens.

[0158] 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.

[0159] 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.

[0160] 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.

[0161] 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.

[0162] 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.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] 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.

[0167] Furthermore, a circular diffusing film is fitted to the fiber optic output port at the top of the probe. This diffusing film increases the uniformity of the light and simultaneously increases the divergence angle of the emitted light.

[0168] For example, in some embodiments, the included angle α between the first axis and the second axis is approximately 110-135°.

[0169] In some embodiments, the relay imaging segment 20 includes:

[0170] The first lens group 20A, the second lens group 20B, and the third lens group 20C are 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.

[0171] In this embodiment, the lens group uses a rod-shaped cemented lens.

[0172] See Figure 4 As shown, the lens group includes lens I 21, lens II 22, lens III 23, lens IV 24, and lens V 25.

[0173] In some embodiments, such as Figure 4 As shown, the imaging segments are arranged from left to right as follows:

[0174] Front protective glass, first cemented doublet achromatic lens 31, biconcave lens 32, second cemented doublet achromatic lens 33, negative meniscus lens 34.

[0175] Among them, the function of cemented doublet achromatic lens is to eliminate chromatic aberration, while the function of negative meniscus cemented lens is to correct aberration.

[0176] The first fixing structure 36 and the second fixing structure 37 are used to fix the first cemented doublet achromatic lens 31 and the biconcave lens 32 in place.

[0177] The third fixing structure is used to limit and fix the second cemented doublet achromatic lens 33 and the negative meniscus cemented lens 34.

[0178] The fixing sleeve 35 is used to accommodate lens structures such as fixed imaging segments.

[0179] In some embodiments, the field of view (FOV) is 120° diagonally.

[0180] 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.

[0181] 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.

[0182] 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.

[0183] 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.

[0184] Furthermore, in some embodiments, the endoscope further includes a connector 51, 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.

[0185] In some embodiments, the endoscope is further provided with a focusing ring 52. In some embodiments, a camera mount 53 is provided at the rear end of the imaging segment for mounting a camera 54.

[0186] 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:

[0187] Table 1 - Test Data Table

[0188] 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.

[0189] To further verify the performance of the endoscope of the present invention, Figure 1 The following calculation is performed using the structure shown as an example:

[0190] In this example, the objective lens section L1 of the endoscope is 1.0 cm long, the relay imaging section L2 is 7 cm long, the width of the objective lens and the relay imaging section (i.e., the inner diameter of the tube) is 0.65 cm, the outer diameter of the tube is 0.8 cm, and the angle between the objective lens section and the relay imaging section is 110°.

[0191] 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.

[0192] Figure 6 The horizontal axis represents the field of view, and the vertical axis represents the root mean square wavefront aberration. D1, D2, D3, and D4 represent the polynomial aberration and the root mean square wavefront aberrations of blue light (0.486 nm), green light (0.586 nm), and red light (0.656 nm), respectively.

[0193] from 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).

[0194] 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.

[0195] 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.

[0196] 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.

[0197] 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 7As 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.

[0198] 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.

[0199] Figure 8 The lateral aberration range of the endoscope's optical system is shown to be -0.08 mm to +0.12 mm. The range of lateral aberration is an important parameter in optical systems, representing the focusing differences of different wavelengths of light at different heights. The results for axial chromatic aberration will show the differences at different wavelengths and heights.

[0200] Among them, A1, A2, and A3 are the on-axis lateral aberrations of blue light (wavelength 0.486nm), green light (wavelength 0.586nm), and red light (wavelength 0.656nm), respectively.

[0201] 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 means that the image quality of the optical system may not meet the design requirements, necessitating optimization and adjustment. Conversely, Figure 8 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.

[0202] Figures 10a-10h These are photographs of the lip mucosa observed through the endoscope in this example. The area in the middle of the frame is the area that the doctor needs to focus on, and the luminous area is water on the surface of the oral mucosa, which forms a mirror reflection during observation.

[0203] The distribution of capillaries (the dark stripes in the image) can be clearly observed in the above figure, 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, doctors can easily adjust the viewing angle using the three-point-limited endoscope to obtain multiple clear photographs of the sensitive area.

[0204] 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).

[0205] To verify the imaging effect of the endoscope proposed in this invention, the imaging clarity (by object-side resolution and object-side pixels) at different object distances is calculated below.

[0206] In this context, object height refers to the position of an object relative to the observer or imaging system within an optical system.

[0207] Image height refers to the height of the image formed by an imaging system (such as a lens) on the imaging plane.

[0208] Image resolution refers to the minimum distance between two image points that a lens can distinguish.

[0209] Object resolution refers to the minimum distance between two object points that can be distinguished.

[0210] An object-space pixel refers to a single pixel on the imaging plane that represents the physical size of the object space, measured in μm.

[0211] When the object distance is -5mm.

[0212] Table 2-1

[0213] Table 2-2

[0214] Table 2-3

[0215] When the object distance is -8mm.

[0216] Table 2-4

[0217] Table 2-5

[0218] Table 2-6

[0219] When the object distance is -10mm.

[0220] Table 2-7

[0221] Table 2-8

[0222] Table 2-9

[0223] Tables 2-1 to 2-9 show that the imaging is clear at different locations in the oral cavity when the probe is 5mm to 10mm away from the target.

[0224] 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.

[0225] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a computer terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0226] The embodiments of the present invention have been described above 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 imaging device, characterized in that, include: A tube for transmitting images, the tube comprising: An objective lens section having a first axis, the objective lens section having a length of 0.5-2.5 cm; The relay lens segment has a second axis, the angle α between the first axis and the second axis is 90°-135°, and the length of the relay imaging segment is 3-10cm; A reflective lens is provided at the intersection of the first axis and the second axis. The reflective lens reflects the image output by the objective lens segment and guides the reflected image to the relay imaging segment. The tube wall, corresponding to the junction between the objective lens section and the relay imaging section, is made of a rigid material.

2. The imaging device according to claim 1, characterized in that, The width of the objective lens segment is 0.3-1.0 cm.

3. An imaging device according to claim 1, characterized in that, The width of the relay imaging segment is 0.3-1.0 cm.

4. An imaging device according to claim 1, characterized in that, The included angle α is 110°-135°.

5. An imaging device according to claim 1, characterized in that, The relay imaging segment includes at least one set of cemented lenses.

6. An imaging device according to claim 5, characterized in that, The cemented lens is a rod-shaped cemented lens.

7. An imaging device according to claim 1, characterized in that, The objective lens section is provided with a negative power lens, a positive power lens, a cemented doublet achromatic lens and a plano-convex lens in sequence from its input end to its output end. The direction from the input end to the output end is the direction in which the image is transmitted within the objective lens section.

8. An imaging device according to claim 7, characterized in that, A first aperture is provided between the negative power lens and the positive power lens, and a second aperture is provided between the positive power lens and the cemented doublet achromatic lens.

9. An imaging device according to claim 1, characterized in that, The rigid material includes one or more of the following: metal, plastic, metal-plastic composite, ceramic, and opaque glass.

10. An imaging device according to claim 1, characterized in that, At least one optical fiber is provided on the inner side of the tube wall, and the optical fiber is used to transmit the light source.

Images