Endoscope imaging system and endoscope

Abstract

The utility model relates to the technical field of endoscopes, and discloses an endoscope imaging system and an endoscope. The endoscope imaging system comprises a glass lens assembly, a diaphragm assembly, a liquid lens assembly and a power supply, wherein the liquid lens assembly comprises a first liquid lens and a second liquid lens which are arranged on the two sides of the diaphragm assembly respectively, and the power supply is electrically connected with the liquid lens assembly. After the liquid lens assembly is arranged on the endoscope imaging system, the power supply applies voltage to the two ends of the liquid lens, the curvature or thickness of the liquid lens is controlled by controlling the voltage applied to the two ends of the liquid lens, the imaging definition at different working distances is guaranteed, and then the imaging definition in different depth-of-field ranges is guaranteed; high resolution and large depth of field can be both considered, and further miniaturization of the endoscope is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of endoscopes, and in particular to an endoscope imaging system and an endoscope. Background Art

[0002] An electronic flexible endoscope is a device that can be inserted into the human body along the natural cavity for inspection or treatment. The imaging system should have a large depth of field when working, so that it is convenient to observe the target part from near to far; at the same time, it should provide a larger imaging resolution so that doctors can observe the lesion more carefully.

[0003] The endoscope imaging systems currently used are all made of traditional glass materials, and it is difficult to change the design after it is finalized. For the miniaturization of endoscopes, under the premise of unchanged depth of field, to increase the resolution, either increase the diffraction limit or increase the magnification. However, as the size of the camera element becomes smaller and smaller, the magnification is also getting smaller and smaller. To further improve the resolution, it is inevitable to increase the diffraction limit or even break the diffraction limit. The best way to increase the diffraction limit is to increase the aperture (that is, reduce the F number). Correspondingly, as the aperture continues to increase (the F number continues to decrease), the corresponding depth of field will also be smaller, and the contradiction between the two will always exist.

[0004] For imaging systems made of traditional glass materials, a larger aperture can only be achieved within a small depth of field to achieve a larger imaging resolution. One method is to use a zoom lens, which uses a mechanical structure to control the movement of the internal lens to ensure clear imaging within the full depth of field. This is equivalent to adjusting the air gap of the internal lens. However, it is also very difficult to use an electronic system to move the lens in a small space, and there are also high requirements for the accuracy and size of the lenses and structural parts.

[0005] In summary, ensuring a larger depth of field and improving imaging resolution are mutually restrictive, which affects the miniaturization design of endoscopes. Utility Model Content

[0006] In view of this, the utility model provides an endoscope imaging system and an endoscope to solve the problem that the improvement of imaging resolution and the guarantee of a larger depth of field are mutually restricted, which affects the miniaturization design of the endoscope.

[0007] In a first aspect, the utility model provides an endoscope imaging system, the imaging system having an object side and an imaging side, and comprising:

[0008] An aperture assembly, located at the boundary between the object side and the imaging side;

[0009] A liquid lens assembly, comprising a first liquid lens and a second liquid lens respectively arranged on both sides of the aperture assembly;

[0010] A glass lens assembly is spaced apart from the outside of the liquid lens assembly; and

[0011] A power source is electrically connected to the liquid lens assembly.

[0012] Beneficial effects: After the endoscope imaging system is provided with a liquid lens assembly, a power supply applies a voltage to both ends of the liquid lens. By controlling the voltage applied to both ends of the liquid lens to control the curvature or thickness of the liquid lens, the imaging clarity at different working distances is ensured, thereby ensuring the imaging clarity within different depths of field, and being able to take into account both high resolution and large depth of field, thereby achieving further miniaturization of the endoscope. The endoscope imaging system combines a liquid lens with a traditional glass lens, avoiding the limitations of the small aperture and low diffraction limit of traditional endoscope lenses, achieving an increase in the diffraction limit in a miniaturized structure, and improving the imaging quality without changing the depth of field. In addition, the glass lens assembly is spaced apart on the outside of the liquid lens assembly to play a protective role. The glass lens assembly can not only play an insulating isolation role to prevent the risk of leakage when the liquid lens assembly is powered on, thereby improving electrical safety, but the glass lens assembly can also prevent the liquid lens from being worn, thereby achieving the purpose of physical protection.

[0013] In some optional embodiments, the glass lens assembly includes a first glass lens and a second glass lens, and the first glass lens, the first liquid lens, the aperture assembly, the second liquid lens and the second glass lens are arranged in sequence along the light propagation direction of the endoscopic imaging system.

[0014] Beneficial effects: The first glass lens and the first liquid lens constitute a front lens group, and the first liquid lens can correct the aberration of the first glass lens; the second liquid lens and the second glass lens constitute a rear lens group, wherein the second liquid lens compensates for the remaining aberration after correction of the first liquid lens, and the imaging clarity is maximized after correction by the two liquid lenses.

[0015] In some optional embodiments, the liquid lens assembly further includes an isolation glass, and the isolation glass is disposed between the first liquid lens and the second liquid lens.

[0016] Beneficial effect: An isolation glass is arranged between the first liquid lens and the second liquid lens to separate the two, thereby preventing the first liquid lens and the second liquid lens from interfering with each other when voltage control is performed on them.

[0017] In some optional embodiments, the aperture assembly is disposed on a side of the isolation glass facing the second liquid lens.

[0018] Beneficial effects: The isolation glass serves as both a fixed component of the fixed aperture assembly and an isolation component of the two liquid lenses, and is multifunctional, can reduce the number of components, and has a more compact structure.

[0019] In some optional embodiments, the first liquid lens and the second liquid lens are both gradient refractive index liquid crystal lenses; the gradient refractive index liquid crystal lenses are formed by ITO glass wrapping liquid crystal; when voltage is applied to both sides of the gradient refractive index liquid crystal lens, the liquid crystal inside exhibits different orientations, thereby generating a refractive index gradient.

[0020] Beneficial effect: When voltage is applied on both sides of the gradient refractive index liquid crystal lens, the liquid crystal inside the lens presents different orientations, thereby generating a refractive index gradient, thereby regulating the transmission direction of light and realizing optical functions.

[0021] In some optional embodiments, an imaging sensor is spaced apart from the second liquid lens on one side of the second glass lens, and a protective glass is disposed on the imaging sensor.

[0022] Beneficial effect: A protective glass is arranged on the imaging sensor to protect the imaging sensor and improve the reliability of the imaging sensor.

[0023] In some optional embodiments, the aperture assembly includes an aperture stop disposed on the isolation glass.

[0024] Beneficial effects: By controlling the number and / or direction and / or size of aperture stops, the amount of light passing through the imaging system can be controlled, thereby affecting the brightness and contrast of the imaging system and controlling the diffraction limit of the optical system; and the aperture stop can correct off-axis aberrations to ensure imaging quality.

[0025] In some optional embodiments, a limiting component is provided on the first liquid lens and the second liquid lens.

[0026] Beneficial effects: The limiting component has a centering function to ensure the spacing between each lens, and also limits the liquid lens to a specific range, making it easier to install and fix.

[0027] In some optional embodiments, the limiting assembly includes two fixing rings respectively arranged on the circumference of the first liquid lens and the second liquid lens.

[0028] Beneficial effects: The fixed ring is used as the limiting component, the structure is simple and the centering is reliable.

[0029] In a second aspect, the utility model further provides an endoscope, comprising the endoscopic imaging system described in any one of the above items.

[0030] Beneficial effects: The endoscope has the endoscopic imaging system of the present application, the liquid lens assembly is combined with the glass lens assembly as a zoom lens system, and the curvature of the liquid lens is controlled by applying voltage to realize a large aperture and high diffraction limit imaging system, while ensuring that the original depth of field remains unchanged. The endoscope is not only convenient for observing the image of the target part from near to far, but also provides a greater imaging resolution, which is convenient for doctors to observe the lesion site more carefully; and after setting two liquid lenses for aberration correction, the number of lenses used is reduced, thereby realizing the miniaturization and lightweight of the endoscope. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a schematic cross-sectional structure diagram of an endoscope imaging system according to an embodiment of the utility model;

[0033] Figure 2 for Figure 1 A diagram showing the identification of each optical transmission surface in the endoscopic imaging system;

[0034] Figure 3 This is a field curvature distortion diagram of an endoscope under close-range conditions according to an embodiment of the utility model;

[0035] Figure 4 A vertical axis chromatic aberration diagram of an endoscope under close-up conditions according to an embodiment of the utility model;

[0036] Figure 5 This is an MTF curve diagram of an endoscope under close-range conditions according to an embodiment of the utility model;

[0037] Figure 6 A field curvature distortion diagram of an endoscope under medium-range conditions according to an embodiment of the utility model;

[0038] Figure 7 A vertical axis chromatic aberration diagram of an endoscope under mid-range conditions according to an embodiment of the utility model;

[0039] Figure 8 This is an MTF curve diagram of an endoscope under medium-range conditions according to an embodiment of the utility model;

[0040] Fig. 9 A field curvature distortion diagram of an endoscope under long-range conditions according to an embodiment of the utility model;

[0041] Fig.10 A vertical axis chromatic aberration diagram of an endoscope under long-range conditions according to an embodiment of the utility model;

[0042] Fig.11 The MTF curve diagram of an endoscope under long-range conditions according to an embodiment of the present utility model is shown in FIG.

[0043] Description of reference numerals:

[0044] 1. The first glass lens;

[0045] 2. Limiting components;

[0046] 3. The first liquid lens;

[0047] 4. Isolation glass;

[0048] 5. Second liquid lens;

[0049] 6. Second glass lens;

[0050] 7. Protect glass;

[0051] 8. Imaging sensor;

[0052] 9. Power supply;

[0053] 10. Aperture assembly. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0055] In the description of the utility model, it should be noted that, unless otherwise specified, "multiple" means two or more; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the utility model. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0056] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0057] Combine the following Figures 1 to 11 , describing an embodiment of the utility model.

[0058] It should be noted that the liquid lens referred to in this article is a high-transmittance thin film capsule wrapped in a special liquid. Under the action of voltage, the thickness, shape and refractive index of the lens can be adjusted by utilizing the principle of electrowetting on the medium to achieve rapid zoom.

[0059] According to an embodiment of the present utility model, on the one hand, as Figure 1 As shown, an endoscope imaging system is provided, the imaging system having an object side and an imaging side, and comprising:

[0060] The aperture assembly 10 is located at the boundary between the object side and the imaging side;

[0061] The liquid lens assembly comprises a first liquid lens 3 and a second liquid lens 5 respectively arranged on both sides of the aperture assembly 10;

[0062] A glass lens assembly is spaced apart from the outside of the liquid lens assembly; and

[0063] The power source 9 is electrically connected to the liquid lens assembly through a wire.

[0064] After the endoscope imaging system is provided with a liquid lens assembly, the power supply 9 applies a voltage to both ends of the liquid lens, and controls the curvature or thickness of the liquid lens by controlling the voltage applied to both ends of the liquid lens, thereby ensuring the imaging clarity at different working distances, and then ensuring the imaging clarity within different depths of field, and being able to take into account both high resolution and large depth of field, thereby achieving further miniaturization of the endoscope. The endoscope imaging system combines a liquid lens and a traditional glass lens, avoiding the limitations of the small aperture and low diffraction limit of the traditional endoscope lens, achieving an improved diffraction limit in a miniaturized structure, and improving the imaging quality without changing the depth of field. The first liquid lens 3 and the second liquid lens 5 are respectively arranged on both sides of the aperture assembly 10, which can reduce the number of lenses of the imaging system compared with the method of only setting one liquid lens, thereby achieving further miniaturization. In addition, the glass lens assembly is arranged at intervals on the outside of the liquid lens assembly to play a protective role. The glass lens assembly can not only play an insulating isolation role, prevent the risk of leakage when the liquid lens assembly is connected to the power supply, and improve electrical safety, but also the glass lens assembly can prevent the liquid lens from being worn, thereby achieving the purpose of physical protection.

[0065] In some embodiments, the glass lens assembly includes a first glass lens 1 and a second glass lens 6, and the first glass lens 1, the first liquid lens 3, the aperture assembly 10, the second liquid lens 5 and the second glass lens 6 are arranged in sequence along the light propagation direction of the endoscopic imaging system.

[0066] The first glass lens 1 and the first liquid lens 3 constitute a front lens group, and the first liquid lens 3 can correct the aberration of the first glass lens 1; the second liquid lens 5 and the second glass lens 6 constitute a rear lens group, wherein the second liquid lens 5 compensates for the remaining aberration after correction of the first liquid lens 3, and the imaging clarity is maximized after correction by the two liquid lenses.

[0067] In some embodiments, the liquid lens assembly further includes an isolation glass 4 , which is disposed between the first liquid lens 3 and the second liquid lens 5 .

[0068] An isolation glass 4 is provided between the first liquid lens 3 and the second liquid lens 5 to separate the two and prevent mutual interference when voltage control is performed on the first liquid lens 3 and the second liquid lens 5. The isolation glass 4 prevents the first liquid lens 3 and the second liquid lens 5 from interfering with each other, thereby improving the reliability of the liquid lens assembly.

[0069] In some embodiments, the aperture assembly 10 is disposed on a side of the isolation glass 4 facing the second liquid lens 5 .

[0070] The isolation glass 4 serves as both a fixed component of the fixed aperture assembly 10 and an isolation component of the two liquid lenses. It is multifunctional, can reduce the number of components, and has a more compact structure.

[0071] Specifically, the isolation glass 4 can be made of flat glass, which is convenient for fixing the aperture and has a simple structure.

[0072] In some embodiments, the first liquid lens 3 and the second liquid lens 5 are both gradient refractive index liquid crystal lenses.

[0073] When voltage is applied on both sides of the gradient refractive index liquid crystal lens, the liquid crystal inside the lens exhibits different orientations, thereby generating a refractive index gradient, thereby regulating the transmission direction of light and realizing optical functions.

[0074] Specifically, the gradient refractive index liquid crystal (GRIN PDLC) lens is composed of ITO (Indium-Tin Oxide) glass wrapped with liquid crystal, and ITO glass has conductive properties. During the process of uniform ultraviolet light and mask exposure to liquid crystal, the liquid crystal molecules in the weak ultraviolet exposure area are larger, and the corresponding threshold voltage is smaller. Since the threshold voltages of liquid crystal molecules in different areas of the lens are different, when voltage is applied on both sides of the ITO glass, the liquid crystal inside the lens presents different orientations, thereby generating a refractive index gradient.

[0075] In some embodiments, an imaging sensor 8 is spaced apart from the side of the second glass lens 6 away from the second liquid lens 5 , and a protective glass 7 is disposed on the imaging sensor 8 .

[0076] A protective glass 7 is provided on the imaging sensor 8 to protect the imaging sensor 8 and improve the reliability of the imaging sensor 8 .

[0077] In some embodiments, the aperture assembly 10 includes an aperture stop disposed on the isolation glass 4 .

[0078] By controlling the number and / or direction and / or size of aperture stops, the amount of light passing through the imaging system can be controlled, thereby affecting the brightness and contrast of the imaging system and controlling the diffraction limit of the optical system; and the aperture stop can correct off-axis aberrations to ensure imaging quality.

[0079] Specifically, the number, size and opening direction of the aperture diaphragms are adjusted to control the amount of light passing through the imaging system. Different settings and selections of the various parameters of the aperture diaphragms can achieve corresponding imaging brightness and contrast and achieve different imaging effects.

[0080] In some embodiments, a limiting assembly 2 is disposed on the periphery of the first liquid lens 3 and the second liquid lens 5 .

[0081] The limiting component 2 has a centering function to ensure the spacing between each lens, and also limits the liquid lens to a specific range to facilitate installation and fixation.

[0082] In some embodiments, the limiting assembly 2 includes two fixing rings respectively disposed around the first liquid lens 3 and the second liquid lens 5 .

[0083] A fixing ring arranged on the peripheral side of the liquid lens is used as the limiting component 2, which has a simple structure and reliable centering.

[0084] Specifically, the fixing ring is a hollow cylindrical structure, and the liquid lens is embedded in the fixing ring, so as to be limited and fixed by the wall surface of the fixing ring.

[0085] According to an embodiment of the present utility model, on the other hand, an endoscope is provided, comprising any one of the above endoscopic imaging systems.

[0086] The endoscope has the endoscopic imaging system of the present application. The liquid lens component is combined with the glass lens component as a zoom lens system. The curvature of the liquid lens is controlled by applying voltage to realize a large aperture and high diffraction limit imaging system, while ensuring that the original depth of field remains unchanged. The endoscope is not only convenient for observing the image of the target part from near to far, but also provides a greater imaging resolution, which is convenient for doctors to observe the lesion site more carefully; and after setting two liquid lenses for aberration correction, the number of lenses used is reduced, thereby realizing the miniaturization and lightweight of the endoscope.

[0087] See also Figures 3 to 11 , gives the imaging conditions of a large aperture imaging system of a specific embodiment of the utility model at three working distances: near-view, mid-view and far-view. Figure 1 The endoscope optical imaging system shown in the figure numbers each optical transmission surface from left to right along its axis, see Figure 2 The specific parameters of each conductive surface are shown in Table 1 (R is the curvature radius of the lens, d is the working distance, N d is the refractive index, V d is the Abbe number):

[0088] Table 1

[0089] R d <![CDATA[N d ]]> <![CDATA[V d ]]> Monogatari d1 (variable) M1 ∞ 0.3 2.0004 25.426 M2 0.55 0.35 M3 R1 (variable) 0.868 1.8081 22.698 M4 R2 (variable) 0.14 M5 ∞ 0.2 1.5168 64.199 M6(Aperture) ∞ 0.04 M7 ∞ 0.53 1.804 46.574 M8 R3 (variable) 0.02 M9 1.106 0.8 1.755 52.321 M10 -0.685 0.3 1.9591 17.72 M11 ∞ 0.425 M12 ∞ 0.1 1.5168 64.199 M13 ∞ 0.0

[0090] For other relevant parameters, see Table 2:

[0091] Table 2

[0092]

[0093]

[0094] Figure 3-Figure 5They are the field curvature distortion diagram, vertical axis chromatic aberration diagram and MTF curve diagram under the condition of close-range d1=3mm; Figure 6-Figure 8 They are the field curvature distortion diagram, vertical axis chromatic aberration diagram and MTF curve diagram under the condition of mid-ground d1=10mm; Figure 9-11 They are the field curvature distortion diagram, vertical axis chromatic aberration diagram and MTF curve diagram under the condition of distant view d1=100mm. It can be seen from the figure that the aberrations of distant, medium and near views all meet the requirements, and increasing the aperture (i.e. reducing the F number) makes the MTF diffraction limit reach a higher level. The voltage at different working distances is controlled by an algorithm to control the curvature radius of the liquid lens to ensure the imaging clarity at different working distances, while taking into account the large depth of field under the conditions of large aperture and high diffraction limit. This ensures the image observation clarity of the miniaturized endoscope at different working distances, while also providing a greater imaging resolution, which facilitates doctors to observe the lesion site more carefully and improves the overall performance of the endoscope.

[0095] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. An endoscopic imaging system, characterized in that: The imaging system has an object side and an imaging side, and comprises: An aperture assembly (10) located at the boundary between the object side and the imaging side; A liquid lens assembly, comprising a first liquid lens (3) and a second liquid lens (5) respectively arranged on both sides of the aperture assembly (10); A glass lens assembly is spaced apart from the outside of the liquid lens assembly; and A power source (9) is electrically connected to the liquid lens assembly.

2. The endoscopic imaging system according to claim 1, characterized in that: The glass lens assembly comprises a first glass lens (1) and a second glass lens (6), and the first glass lens (1), the first liquid lens (3), the aperture assembly (10), the second liquid lens (5) and the second glass lens (6) are arranged in sequence along the light propagation direction of the endoscopic imaging system.

3. The endoscopic imaging system according to claim 2, characterized in that: The liquid lens assembly further comprises an isolation glass (4), wherein the isolation glass (4) is arranged between the first liquid lens (3) and the second liquid lens (5).

4. The endoscopic imaging system according to claim 3, characterized in that: The aperture assembly (10) is arranged on a side of the isolation glass (4) facing the second liquid lens (5).

5. The endoscopic imaging system according to claim 1, characterized in that: The first liquid lens (3) and the second liquid lens (5) are both gradient refractive index liquid crystal lenses; the gradient refractive index liquid crystal lenses are formed by ITO glass encapsulating liquid crystal; when voltage is applied to both sides of the gradient refractive index liquid crystal lens, the liquid crystal inside exhibits different orientations, thereby generating a refractive index gradient.

6. The endoscopic imaging system according to claim 2, characterized in that: An imaging sensor (8) is arranged at a distance on a side of the second glass lens (6) away from the second liquid lens (5), and a protective glass (7) is arranged on the imaging sensor (8).

7. The endoscopic imaging system according to claim 3, characterized in that: The aperture assembly (10) comprises an aperture aperture arranged on the insulating glass (4).

8. The endoscopic imaging system according to any one of claims 1 to 7, characterized in that: A limiting component (2) is provided on the first liquid lens (3) and the second liquid lens (5).

9. The endoscopic imaging system according to claim 8, characterized in that: The limiting assembly (2) comprises two fixing rings which are respectively arranged on the circumference of the first liquid lens (3) and the second liquid lens (5).

10. An endoscope, characterized in that: An endoscopic imaging system comprising any one of claims 1 to 9.

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