Imaging element and capsule endoscope

Abstract

This invention discloses an imaging element and a capsule endoscope. The imaging element for a capsule endoscope according to an embodiment of the invention includes a central portion providing an optical path for imaging; a peripheral portion forming an integral structure with the central portion; and a connecting portion adjacent to the peripheral portion for connecting with the outer shell of the capsule endoscope to form a closed cavity. The outer and inner surfaces of the central portion have different radii of curvature. According to the imaging element and capsule endoscope of this invention, the imaging element is connected to the outer shell of the capsule endoscope to form a closed cavity, isolating the internal components of the capsule endoscope from external liquids, ensuring the effectiveness of the device and the safety of the human body; and improving the light transmittance and imaging quality of the capsule endoscope.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to an imaging element and a capsule endoscope. Background Technology

[0002] Currently, patients can take a capsule endoscope with an internal image acquisition and wireless communication device orally to collect images inside the digestive tract. Doctors then use external instruments to receive the images taken by the capsule endoscope to understand the condition of the patient's digestive tract and make a medical diagnosis.

[0003] like Figure 1 As shown, a capsule endoscope according to the prior art includes an imaging lens group 100 and a transparent dome 200. The imaging lens group 100 is used for image acquisition. The transparent dome 200, as an additional lens window, primarily functions as a sealed transparent body to separate the electronic components inside the capsule from liquids such as water, ensuring the effectiveness of the electronic components and the safety of the human body. The use of the transparent dome 200 often brings the following problems:

[0004] I. A transparent dome 200 is generally composed of concentric hemispheres with the same inner and outer radii. Therefore, the dome's optical power φ = 0, meaning it has no effect on converging or diverging light; its only optical function is as an optical window. The transmittance of a transparent dome 200 cannot be 100%, which would lead to a decrease in the utilization rate of lighting light due to the dome.

[0005] 2. The transparent dome 200 forms a hemispherical cavity structure. When light emitted from the light source in the capsule endoscope shines on the inner and outer surfaces of the transparent dome 200, it will be reflected. The reflected light will be received by the imaging lens group 100, which is called stray light, resulting in a deterioration in image quality.

[0006] Third, the transparent dome 200, as an additional material, increases the additional cost. Summary of the Invention

[0007] In view of the above problems, the purpose of this invention is to provide an imaging element and a capsule endoscope, thereby improving the light transmittance and imaging quality of the capsule endoscope.

[0008] According to one aspect of the present invention, an imaging element for a capsule endoscope is provided, comprising: a central portion providing an optical path for imaging; a peripheral portion forming an integral structure with the central portion; and a connecting portion adjacent to the peripheral portion for connecting with the outer shell of the capsule endoscope to form a closed cavity, wherein the outer surface and the inner surface of the central portion have different radii of curvature from each other.

[0009] Preferably, the outer surface of the middle portion and the outer surface of the peripheral portion form a first surface with a smooth curve.

[0010] Preferably, the inner surface of the middle portion and the inner surface of the peripheral portion form a second surface that conforms to multiple components inside the capsule endoscope.

[0011] Preferably, the inner surface of the peripheral portion is formed with a cavity to accommodate the plurality of components.

[0012] Preferably, the plurality of components include a light source for illumination, and the peripheral portion provides an optical path for illumination.

[0013] Preferably, the connecting part and one of the side walls of the outer casing are provided with a groove, and the other is provided with a flange, and the groove engages with the flange.

[0014] Preferably, the middle portion forms any one of a plano-convex lens, a plano-concave lens, a biconvex lens, a biconcave lens, or a concave-convex lens.

[0015] Preferably, the imaging element is made of a material whose refractive index is close to that of water.

[0016] Preferably, the imaging element is made of E48R material.

[0017] According to another aspect of the present invention, a capsule endoscope is provided, comprising a housing having a capsule shape having an open top end and a closed bottom end; an imaging element as described above, the imaging element closing the top end of the housing to form a closed cavity; and a plurality of components housed within the closed cavity.

[0018] Preferably, one of the sidewalls of the housing and the connection portion of the imaging element is provided with a flange, and the other is provided with a groove, wherein the flange engages with the groove.

[0019] Preferably, the plurality of components include: a magnet, located in the enclosed cavity, for movement of the capsule endoscope; and a battery, located in the enclosed cavity, for powering the capsule endoscope.

[0020] According to embodiments of the present invention, the imaging element and the capsule endoscope are connected to the outer shell of the capsule endoscope to form a closed cavity to isolate the internal components of the capsule endoscope from the external liquid, thereby ensuring the effectiveness of the internal components and the safety of the human body.

[0021] According to embodiments of the present invention, the imaging element is connected to the outer shell of the capsule endoscope, eliminating the need for an additional dome, thereby improving light transmittance and saving materials and costs.

[0022] According to embodiments of the present invention, the imaging element and capsule endoscope are connected to the outer shell of the capsule endoscope, which reduces light reflection and improves imaging quality. Attached Figure Description

[0023] The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0024] Figure 1 A schematic diagram of the structure of a capsule endoscope according to the prior art is shown;

[0025] Figure 2 A schematic diagram of the structure of an imaging element for a capsule endoscope according to a first embodiment of the present invention is shown;

[0026] Figure 3 A schematic diagram of the structure of an imaging element for a capsule endoscope according to a second embodiment of the present invention is shown;

[0027] Figure 4 A schematic diagram of the imaging lens assembly for a capsule endoscope according to a first embodiment of the present invention is shown;

[0028] Figure 5 A schematic diagram of the imaging lens assembly for a capsule endoscope according to a second embodiment of the present invention is shown;

[0029] Figure 6 A schematic diagram of the structure of a capsule endoscope according to an embodiment of the present invention is shown;

[0030] Figure 7 A schematic diagram of the internal structure of a capsule endoscope according to an embodiment of the present invention is shown;

[0031] Figure 8 A two-dimensional layout diagram of the imaging lens assembly of a capsule endoscope according to a third embodiment of the present invention is shown at a working distance of 0 mm.

[0032] Figure 9 The MTF curve of the capsule endoscope according to the third embodiment of the present invention at a working distance of 0 mm is shown.

[0033] Figure 10 A dot plot of a capsule endoscope according to a third embodiment of the present invention on a ray-tracing plane at a working distance of 0 mm is shown.

[0034] Figure 11 The diagram shows the relative distortion curve of a capsule endoscope according to a third embodiment of the present invention at a working distance of 0 mm;

[0035] Figure 12 A two-dimensional layout diagram of the imaging lens assembly of a capsule endoscope according to a third embodiment of the present invention is shown at a working distance of 8 mm.

[0036] Figure 13The MTF curve of the capsule endoscope according to the third embodiment of the present invention at a working distance of 8 mm is shown;

[0037] Figure 14 A dot plot of a capsule endoscope according to a third embodiment of the present invention on a ray-tracing plane at a working distance of 8 mm is shown.

[0038] Figure 15 The diagram shows the relative distortion curve of a capsule endoscope according to a third embodiment of the present invention at a working distance of 8 mm;

[0039] Figure 16 A two-dimensional layout diagram of the imaging lens assembly of a capsule endoscope according to a third embodiment of the present invention is shown at a working distance of 30 mm.

[0040] Figure 17 The MTF curve of the capsule endoscope according to the third embodiment of the present invention at a working distance of 30 mm is shown.

[0041] Figure 18 A dot plot of a capsule endoscope according to a third embodiment of the present invention on a ray-tracing plane at a working distance of 30 mm is shown.

[0042] Figure 19 A relative distortion curve of a capsule endoscope according to a third embodiment of the present invention at a working distance of 30 mm is shown.

[0043] Figure 20 The parameters of each component element of the imaging lens assembly according to a third embodiment of the present invention are shown;

[0044] Figure 21 The parameters of each component element of the imaging lens assembly according to a third embodiment of the present invention are shown. Detailed Implementation

[0045] Various embodiments of the invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale. Furthermore, certain well-known parts may not be shown in the drawings.

[0046] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. Many specific details of the invention, such as the structure, materials, dimensions, processing techniques, and methods of the components, are described below to provide a clearer understanding of the invention. However, as those skilled in the art will understand, the invention may be implemented without following these specific details.

[0047] It should be understood that when describing the structure of a component, when referring to a layer or region as being "above" or "on top of" another layer or region, it can mean that it is directly above the other layer or region, or that it contains other layers or regions between it and the other layer or region. Furthermore, if the component is flipped over, that layer or region will be located "below" or "under" the other layer or region.

[0048] Figure 2 A schematic diagram of the structure of an imaging element for a capsule endoscope according to a first embodiment of the present invention is shown. Figure 2 (a) shows a front view of the imaging element 101. Figure 2 (b) shows a top view of the imaging element 101. Figure 2 As shown, the imaging element 101 according to the first embodiment of the present invention includes a middle portion 1011, a connecting portion 1012 and a peripheral portion 1013.

[0049] Specifically, the imaging element 101 is used for imaging with a capsule endoscope and also serves as an isolation shield for the capsule endoscope. The imaging element 101 is connected to the outer shell of the capsule endoscope to form a closed cavity, acting as an isolation shield. The imaging element 101 includes a central portion 1011, a connecting portion 1012, and a peripheral portion 1013. The outer and inner surfaces of the central portion 1011 have different radii of curvature. The central portion 1011 is, for example, a concave lens, located in the receiving optical path of the capsule endoscope, providing an optical path for imaging. The peripheral portion 1013 forms an integral structure with the central portion 1011. The connecting portion 1012 is adjacent to the peripheral portion 1013 and is used to connect with the outer shell of the capsule endoscope to form a closed cavity. The imaging element 101 is connected to the outer shell of the capsule endoscope to form a closed cavity, acting as an isolation shield to isolate the internal components of the capsule endoscope from the external environment. Imaging element 101, for example, acts as a closed cover to separate the electronic components inside the capsule endoscope from liquids such as water.

[0050] In an optional embodiment of the present invention, the outer surface and the inner surface of the intermediate portion 1011 have different radii of curvature from each other. The intermediate portion 1011 forms any one of a plano-convex lens, a plano-concave lens, a biconvex lens, a biconcave lens, and a concave-convex lens.

[0051] In the above embodiments of the present invention, the conventional dome structure is eliminated, the light transmittance of the lens is improved, the reflection of the dome is reduced, and the material of the dome is reduced, thereby improving the material utilization rate.

[0052] Figure 3 A schematic diagram of the imaging element for a capsule endoscope according to a second embodiment of the present invention is shown. Figure 3As shown, the imaging element 101 according to the second embodiment of the present invention includes a middle portion 1011, a connecting portion 1012 and a peripheral portion 1013.

[0053] Specifically, the imaging element 101 is used for imaging with a capsule endoscope and is also reused as a shield for the capsule endoscope. The imaging element 101 includes a central portion 1011, a connecting portion 1012, and a peripheral portion 1013. The central portion 1011 is located in the receiving optical path of the capsule endoscope and is used for imaging with the capsule endoscope. The upper surface of the central portion 1011 is, for example, convex, and the lower surface is designed with an irregular shape to match other parts of the capsule endoscope. The inner surfaces of the central portion 1011 and the peripheral portion 1013, for example, form second surfaces conformal to multiple components inside the capsule endoscope.

[0054] In a preferred embodiment of the present invention, the outer surface of the middle portion 1011 and the outer surface of the peripheral portion 1013 form a first surface with a smooth curve.

[0055] In an optional embodiment of the present invention, the connecting part 1012 is provided with a groove on one of the side walls of the capsule endoscope housing and a flange on the other, and the groove and the flange engage so that the imaging element 101 and the capsule endoscope housing form a closed cavity.

[0056] In a preferred embodiment of the invention, the imaging element 101 is selected from a material whose refractive index is close to that of water. Optionally, the imaging element 101 is selected from an E48R material with a refractive index of 1.53.

[0057] In the above embodiments of the present invention, the imaging element 101 is in direct contact with water, and a material with a refractive index close to that of water is selected, which can reduce reflections caused by refractive index mismatch.

[0058] Figure 4 A schematic diagram of the imaging lens assembly for a capsule endoscope according to a first embodiment of the present invention is shown. Figure 4 As shown, the imaging lens assembly 100 according to a first embodiment of the present invention includes an imaging element 101 and a second imaging element 102. The imaging element 101 and the second imaging element 102 are arranged sequentially along the light path of the capsule endoscope. The direction of the light path is as follows... Figure 4 As indicated by the middle arrow. Imaging element 101 is used for imaging with the capsule endoscope. Second imaging element 102 is used for imaging with the capsule endoscope. Optionally, imaging element 101 and second imaging element 102 constitute the imaging lens assembly 100 of the capsule endoscope.

[0059] In an optional embodiment of the present invention, the imaging lens assembly 100 includes an imaging element 101, a second imaging element 102 and at least one other imaging component arranged sequentially along the light path of the capsule endoscope, wherein the imaging component includes at least a light source 103.

[0060] Figure 5 A schematic diagram of the imaging lens assembly for a capsule endoscope according to a second embodiment of the present invention is shown. Figure 5 As shown, the imaging lens assembly 100 according to the second embodiment of the present invention includes an imaging element 101, a second imaging element 102 and a light source 103.

[0061] Imaging element 101 and second imaging element 102 are sequentially arranged along the light path of the capsule endoscope. The direction of the light path is as follows: Figure 5 As indicated by the middle arrow, a light source 103 is disposed on the side of the second imaging element 102. The light source 103 is used to provide illumination. The light emitted by the light source 103 passes through the imaging element 101 and is reflected (for example, it shines on the stomach wall and is reflected). The reflected light passes sequentially through the imaging element 101 and the second imaging element 102 to form an image.

[0062] The upper surface of the imaging element 101 is convex, and the lower surface has a shape that matches the second imaging element 102 and the light source 103. The imaging element 101 is in direct contact with the second imaging element 102 and the light source 103.

[0063] In an alternative embodiment of the invention, the inner surface of the peripheral portion 1013 is formed with a cavity to accommodate the plurality of components. The peripheral portion 1013 provides, for example, an optical path for illumination. The light source 103 is located in the cavity formed in the peripheral portion 1013.

[0064] In an optional embodiment of the present invention, the imaging lens group 100 includes an imaging element 101, a second imaging element 102 and at least one other imaging component arranged along the optical path, wherein the imaging component includes at least a light source 103.

[0065] In an optional embodiment of the present invention, the light source 103 is an LED (light-emitting diode), a fluorescent lamp, or another light source.

[0066] In the above embodiments of the present invention, the light emitted by the light source 103 passes directly through the imaging element 101 and is not reflected on the surface of the imaging element (or the reflection is minimal). The imaging element does not (or receives less) the reflected light, thus avoiding the influence of stray light and improving the imaging quality.

[0067] Figure 6 A schematic diagram of a capsule endoscope according to an embodiment of the present invention is shown. Figure 6 As shown, the capsule endoscope according to an embodiment of the present invention includes an imaging element 101 and a housing 300. The imaging element 101 is used for imaging the capsule endoscope and is also reused as a shield for the capsule endoscope. The housing 300 is located on the outermost side of the capsule endoscope and is used to house the specific components of the capsule endoscope.

[0068] The imaging element 101 is connected to the housing 300 to form a closed cavity that separates the electronic components and other parts inside the capsule endoscope from liquids such as water.

[0069] In an optional embodiment of the present invention, a groove is provided on one of the side walls of the connecting part 1012 and the housing 300, and a flange is provided on the other side wall. The groove and the flange engage with each other so that the imaging element 101 and the housing 300 form a closed cavity.

[0070] In an optional embodiment of the present invention, the imaging element 101 includes a central portion 1011, a connecting portion 1012, and a peripheral portion 1013. A housing connecting portion 301 (e.g., a flange provided on the side wall of the housing 300) is provided on the housing 300. The housing connecting portion 301 mates with the connecting portion 1012, enabling a tight connection that makes the interior of the capsule endoscope a closed space (closed cavity). Optionally, adhesive is used to bond the connecting portion 1012 and the housing connecting portion 301 together.

[0071] In an optional embodiment of the present invention, the imaging element 101 and the housing 300 are mechanically fitted and glued together to form a single unit. It should be noted that the connection method between the imaging element 101 and the housing 300 is not limited to this; various connection methods can be adopted while ensuring sealing and integrity.

[0072] In the above embodiments of the present invention, the imaging element 101 and the capsule endoscope housing 300 are mechanically coupled and glued together to form a whole, ensuring the sealing and integrity of the capsule endoscope.

[0073] Figure 7 A schematic diagram of the internal structure of a capsule endoscope according to an embodiment of the present invention is shown. Figure 7 As shown and combined Figure 6 According to an embodiment of the present invention, a capsule endoscope includes an imaging lens assembly 100, a magnet 400, a battery 500, and a housing 300. The imaging lens assembly 100 includes an imaging element 101.

[0074] Imaging element 101 is connected to housing 300 to form a closed cavity, isolating the internal components of the capsule endoscope from external liquids (such as water, gastric juice, etc.). Magnet 400 is located within the closed cavity and is used to sense external magnetic fields to control the movement of the capsule endoscope.

[0075] In an optional embodiment of the present invention, magnet 400 controls the movement of capsule endoscope under the action of external magnetic force.

[0076] like Figure 8As shown, the capsule endoscope imaging assembly of the third embodiment of the present invention includes: an imaging element 101, a second imaging element 102, a third imaging element 103, a fourth imaging element 104, a fifth imaging element 105, a photosensitive glass 106, and an image plane 107. The imaging element 101 is in direct contact with an external liquid 800. The external liquid 800 is, for example, water or gastric juice. An aperture (not shown) is also disposed between the third imaging element 103 and the fourth imaging element 104. Figure 20 The parameters of each component of the imaging lens assembly according to a third embodiment of the present invention are shown. The parameters of each component of the imaging lens assembly can be as follows: Figure 20 As shown in the image. Figure 21 The parameters of each component of the imaging lens assembly according to a third embodiment of the present invention are shown. The parameters of each component of the imaging lens assembly can be as follows: Figure 21 As shown in the image.

[0077] Figure 8 A two-dimensional layout diagram of a capsule endoscope according to a third embodiment of the present invention is shown at a working distance of 0 mm. Figure 8 As shown, according to the third embodiment of the present invention, when the working distance of the capsule endoscope is 0mm, the imaging element 101 is in direct contact with water, the full field of view is 100°, and there is a sufficiently large field of view.

[0078] Figure 9 The diagram shows the MTF (Modulation Transfer Function) curves of a capsule endoscope according to a third embodiment of the present invention at a working distance of 0 mm. The vertical axis represents the MTF value, indicating the degree of contrast attenuation; the horizontal axis represents the spatial frequency, in lp / mm, representing the resolution of the spatial size of the observed object. Curve 1 is the meridional curve at a 0° field of view; curve 2 is the sagittal curve at a 0° field of view; curve 3 is the meridional curve at a 15° field of view; curve 4 is the sagittal curve at a 15° field of view; curve 5 is the meridional curve at a 35° field of view; curve 6 is the sagittal curve at a 35° field of view; curve 7 is the meridional curve at a 50° field of view; and curve 8 is the sagittal curve at a 50° field of view. Curve 1 coincides with curve 2. Figure 9 As shown, the capsule endoscope according to the third embodiment of the present invention exhibits good MTF performance at a working distance of 0 mm, especially the best MTF in the central field of view. As can be seen from the figure, when the MTF is 0.2, the spatial frequency of curves 1 and 2 is 225 lp / mm, i.e., the central field of view MTF20 = 225 lp / mm.

[0079] It should be noted that the above is only an MTF curve diagram of one embodiment of the present invention. Capsule endoscopes of different embodiments have different MTF curves, and the MTF curves of each embodiment can demonstrate that the capsule endoscope according to this embodiment has a good MTF curve.

[0080] Figure 10 A dot plot of a capsule endoscope according to a third embodiment of the present invention on a ray-tracing plane at a working distance of 0 mm is shown. Figure 10 The circle in the image represents the Airy disk of the diffraction pattern. For example... Figure 10 As shown, according to the third embodiment of the present invention, the capsule endoscope has a relatively small circle of confusion when the working distance is 0mm, especially in the central field of view, where the RMS (Root Mean Square) radius of the circle of confusion is 1.3μm. Figure 10 The diagram shows image point arrays at object (OBJ) half-field angles of 0°, 15°, 35°, and 50°, which correspond to image (IMA) half-heights of 0mm, 0.203mm, 0.487mm, and 0.726mm, respectively.

[0081] Figure 11 A relative distortion curve of a capsule endoscope according to a third embodiment of the present invention at a working distance of 0 mm is shown. In the figure, the horizontal axis represents the relative distortion rate; the vertical axis represents the normalized field of view. Figure 11 As shown, the capsule endoscope according to the third embodiment of the present invention exhibits relatively small distortion at a working distance of 0 mm. The distortion is extremely small when the field of view is relatively small. At a full field of view of 70°, the distortion is 10%, and the full field of view distortion is 21%.

[0082] Figure 12 A two-dimensional layout diagram of a capsule endoscope according to a third embodiment of the present invention is shown at a working distance of 8 mm. Figure 12 As shown, according to the third embodiment of the present invention, when the working distance of the capsule endoscope is 8mm, the imaging element 101 is in direct contact with water, the full field of view is 100°, and there is a sufficiently large field of view.

[0083] Figure 13The MTF curve of the capsule endoscope according to the third embodiment of the present invention at a working distance of 8 mm is shown. The vertical axis represents the MTF value, indicating the degree of contrast attenuation; the horizontal axis represents the spatial frequency, in lp / mm, representing the resolution of the spatial size of the observed object. Curve 1 is the meridional curve at a 0° field of view; curve 2 is the sagittal curve at a 0° field of view; curve 3 is the meridional curve at a 15° field of view; curve 4 is the sagittal curve at a 15° field of view; curve 5 is the meridional curve at a 35° field of view; curve 6 is the sagittal curve at a 35° field of view; curve 7 is the meridional curve at a 50° field of view; and curve 8 is the sagittal curve at a 50° field of view. Curve 1 coincides with curve 2. Figure 13 As shown, the capsule endoscope according to the third embodiment of the present invention has the optimal MTF in the central field of view when the working distance is 8 mm. It can be seen from the figure that when the MTF is 0.2, the spatial frequency of curves 1 and 2 is 155 lp / mm, that is, the central field of view MTF20 = 155 lp / mm.

[0084] It should be noted that the above is only an MTF curve diagram of one embodiment of the present invention. Capsule endoscopes of different embodiments have different MTF curves, and the MTF curves of each embodiment can demonstrate that the capsule endoscope according to this embodiment has a good MTF curve.

[0085] Figure 14 A dot plot of a capsule endoscope according to a third embodiment of the present invention on a ray-tracing plane at a working distance of 8 mm is shown. Figure 14 The circle in the image represents the Airy disk of the diffraction pattern. For example... Figure 14 As shown, according to the third embodiment of the present invention, when the working distance of the capsule endoscope is 8 mm, the circle of confusion is in its central field of view, and the RMS radius of the circle of confusion is 3.4 μm. Figure 14 The image point diagrams are shown at object-side (OBJ) half-field angles of 0°, 15°, 35°, and 50°, which correspond to image plane (IMA) half-heights of 0 mm, 0.203 mm, 0.483 mm, and 0.714 mm, respectively.

[0086] Figure 15 A relative distortion curve of a capsule endoscope according to a third embodiment of the present invention at a working distance of 8 mm is shown. In the figure, the horizontal axis represents the relative distortion rate; the vertical axis represents the normalized field of view. Figure 15 As shown, the capsule endoscope according to the third embodiment of the present invention exhibits relatively small distortion at a working distance of 8 mm. The distortion is extremely small even with a relatively small field of view. At a full field of view of 70°, the distortion is 11%, and the full field of view distortion is 22%.

[0087] Figure 16A two-dimensional layout diagram of a capsule endoscope according to a third embodiment of the present invention is shown at a working distance of 30 mm. Figure 16 As shown, according to the third embodiment of the present invention, when the working distance of the capsule endoscope is 30mm, the imaging element 101 is in direct contact with water, the full field of view is 100°, and there is a sufficiently large field of view.

[0088] Figure 17 The MTF curve of the capsule endoscope according to the third embodiment of the present invention at a working distance of 30 mm is shown. The vertical axis represents the MTF value, indicating the degree of contrast attenuation; the horizontal axis represents the spatial frequency, in lp / mm, representing the resolution of the spatial size of the observed object. Curve 1 is the meridional curve at a 0° field of view; curve 2 is the sagittal curve at a 0° field of view; curve 3 is the meridional curve at a 15° field of view; curve 4 is the sagittal curve at a 15° field of view; curve 5 is the meridional curve at a 35° field of view; curve 6 is the sagittal curve at a 35° field of view; curve 7 is the meridional curve at a 50° field of view; and curve 8 is the sagittal curve at a 50° field of view. Curve 1 coincides with curve 2. Figure 17 As shown, according to the third embodiment of the capsule endoscope of the present invention, the lens MTF is optimal in the central field of view when the working distance is 30mm. It can be seen from the figure that when the MTF is 0.2, the spatial frequency of curves 1 and 2 is 105 lp / mm, that is, the central field of view MTF20 = 105 lp / mm.

[0089] It should be noted that the above is only an MTF curve diagram of one embodiment of the present invention. Capsule endoscopes of different embodiments have different MTF curves, and the MTF curves of each embodiment can demonstrate that the capsule endoscope according to this embodiment has a good MTF curve.

[0090] Figure 18 A dot plot of a capsule endoscope according to a third embodiment of the present invention on a ray-tracing plane at a working distance of 30 mm is shown. Figure 18 The circle in the image represents the Airy disk of the diffraction pattern. For example... Figure 18 As shown, according to the third embodiment of the present invention, when the working distance of the capsule endoscope is 30 mm, the circle of confusion is in the central field of view, and the RMS radius of the circle of confusion is 4.9 μm. Figure 18 The diagram shows point plots at object-side (OBJ) half-field angles of 0°, 15°, 35°, and 50°, which correspond to image plane (IMA) half-heights of 0 mm, 0.203 mm, 0.482 mm, and 0.710 mm, respectively.

[0091] Figure 19 A relative distortion curve of a capsule endoscope according to a third embodiment of the present invention at a working distance of 30 mm is shown. In the figure, the horizontal axis represents the relative distortion rate; the vertical axis represents the normalized field of view. Figure 19 As shown, the capsule endoscope according to the third embodiment of the present invention exhibits relatively small distortion at a working distance of 30 mm. The distortion is extremely small even at a relatively small field of view. The distortion is 11% at a full field of view of 70°, and 23% across the entire field of view.

[0092] The specific third embodiment described above illustrates that the capsule endoscope according to the embodiments of the present invention has practicality and good imaging quality.

[0093] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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. Without further limitation, 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 said element.

[0094] As described above, these embodiments of the present invention do not exhaustively cover all details, nor do they limit the invention to the specific embodiments described. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to effectively utilize the invention and its modifications. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An imaging element for a capsule endoscope, characterized in that, include: The middle section provides the optical path for imaging; The peripheral portion forms an integral structure with the central portion; A connecting portion, adjacent to the peripheral portion, is used to connect with the outer shell of the capsule endoscope to form a closed cavity. The outer and inner surfaces of the middle portion have different radii of curvature. The inner surface of the middle portion and the inner surface of the peripheral portion form a second surface that conforms to multiple components inside the capsule endoscope; The inner surface of the peripheral portion is formed with a cavity to accommodate the plurality of components; The plurality of components include a light source for illumination, and the peripheral portion provides an optical path for illumination; The side of the inner surface of the middle portion away from the outer surface is used to set the second imaging element; The inner surface of the peripheral portion corresponding to the light source and the outer surface of the middle portion are respectively located on both sides of the inner surface of the middle portion; The second surface of the peripheral portion corresponding to the light source is located between the second surface of the middle portion and the light source.

2. The imaging element according to claim 1, characterized in that, The connecting part and the outer casing sidewall are provided with a groove on one of them and a flange on the other, and the groove and the flange engage.

3. The imaging element according to claim 1, characterized in that, The imaging element is made of a material whose refractive index is close to that of water.

4. The imaging element according to claim 3, characterized in that, The imaging element is made of E48R.

5. A capsule endoscope, characterized in that, include: The outer shell is capsule-shaped with an open top and a closed bottom; The imaging element according to any one of claims 1 to 4, wherein the imaging element closes the top end of the housing to form a closed cavity; as well as Multiple components are housed within the enclosed cavity.

6. The capsule endoscope according to claim 5, characterized in that, The sidewall of the housing is provided with a flange on one of the connection parts with the imaging element, and a groove is provided on the other, and the flange engages with the groove.

7. The capsule endoscope according to claim 5, characterized in that, The plurality of components include: A magnet, located within the enclosed cavity, is used for movement of the capsule endoscope; and A battery, located in the enclosed cavity, is used to power the capsule endoscope.

Images