Optical objective lens set and capsule endoscope

Abstract

The present invention proposes an optical objective lens group and a capsule endoscope. The optical objective lens group comprises a first lens, a second lens, an aperture, a third lens, a fourth lens, a fifth lens and a sixth lens from the object side to the image side, wherein the optical focal lengths of the first lens to the sixth lens are negative, positive, positive, negative, positive and positive respectively; and the optical objective lens group satisfies the following relationship: ‑1.7≤f1 / F≤‑1.6; 0.95≤T1 / F≤1.15; 1.1≤V1 / V6≤1.2; the optical objective lens group of the present invention reasonably controls the shape, optical focal length and related parameter relationship of the lenses, so that the optical objective lens group can well correct chromatic aberration, astigmatism, coma, field curvature and distortion, so that the optical objective lens group has the advantages of miniaturization, large field of view and high imaging quality, so that it is convenient to be applied in micro devices.

Description

Technical Field

[0001] The present invention relates to the technical field of medical equipment, and in particular to an optical objective lens group and a capsule endoscope. Background Art

[0002] Capsule endoscope is a commonly used medical device, often used for non-invasive examination. It is mainly used by swallowing. In some scenarios, the capsule is also delivered into the human body through a surgical incision. When the capsule endoscope moves in the human body, the camera component built into the capsule will continuously capture images and send the image data wirelessly to an external device for the doctor to make a diagnosis.

[0003] The capsule endoscope is mainly composed of an internal part and an external part. The internal part mainly includes components such as a lens, a control circuit, a signal transmission module, and a power module, while the external part consists of an image receiver, an image and report processing workstation, and a capsule remote control unit. The capsule endoscope has the characteristics of a one-time application. Compared with traditional endoscopes, it is easy to use, can eliminate the problem of cross infection, and reduces the pain caused to patients during the examination.

[0004] The existing patent document with the publication (announcement) number of US20130163092A1 discloses an endoscope objective optical system. In this scheme, the lens includes four pieces of high-refractive-index glass, and its field of view angle is relatively small, and the full field of view angle is about 90°, resulting in a serious limitation of the field of view, which is not conducive to observation;

[0005] In addition, the diameter of the pylorus and small intestine, the narrowest part of the human intestine, is between 15-25mm, so the size and image height of the lens should not be too large. Summary of the invention

[0006] In view of this, the present invention proposes an optical objective lens group and a capsule endoscope with good imaging quality and a large field of view, so as to solve the problems of small field of view and difficult observation in the existing endoscope objective optical system.

[0007] The technical solution of the present invention is achieved in this way:

[0008] In one aspect, the present invention provides an optical objective lens assembly, which comprises a first lens, a second lens, an aperture, a third lens, a fourth lens, a fifth lens and a sixth lens from the object side to the image side, wherein:

[0009] The first lens has negative optical power, and the object side of the first lens is a flat surface;

[0010] The second lens has positive power, and the second lens is a biconvex lens;

[0011] The third lens has positive power and is a biconvex lens;

[0012] The fourth lens has negative optical power and is a biconcave lens;

[0013] The fifth lens has positive refractive power, and is a meniscus lens with a convex surface facing the object side;

[0014] The sixth lens has positive refractive power;

[0015] The optical objective lens group satisfies the following relationship:

[0016] -1.7≤f1 / F≤-1.6;

[0017] 0.95≤T1 / F≤1.15;

[0018] 1.1≤V1 / V6≤1.2;

[0019] Where f1 is the focal length of the first lens; F is the focal length of the optical objective lens group; T1 is the thickness of the first lens on the optical axis, V1 is the Abbe number of the first lens, and V6 is the Abbe number of the sixth lens.

[0020] On the basis of the above technical solution, preferably, the optical objective lens group satisfies the following relationship:

[0021] 1.9≤f1 / f4≤2.0;

[0022] Wherein, f1 is the focal length of the first lens, and f4 is the focal length of the fourth lens.

[0023] On the basis of the above technical solution, preferably, the optical objective lens group satisfies the following relationship:

[0024] -0.6≤(R3+R4) / (R3-R4)≤-0.2;

[0025] Wherein, R3 is the curvature radius of the object side of the second lens, and R4 is the curvature radius of the image side of the second lens.

[0026] On the basis of the above technical solution, preferably, the optical objective lens group satisfies the following relationship:

[0027] 3≤V1-V2≤9;

[0028] Wherein, V2 is the Abbe number of the second lens.

[0029] On the basis of the above technical solution, preferably, the optical objective lens group satisfies the following relationship:

[0030] 35≤V3-V4≤40;

[0031] Wherein, V3 is the Abbe number of the third lens, and V4 is the Abbe number of the fourth lens.

[0032] On the basis of the above technical solution, preferably, the optical objective lens group satisfies the following relationship:

[0033] -1.0≤(R7+R8) / (R7-R8)≤-0.8;

[0034] Wherein, R7 is the curvature radius of the object side of the fourth lens, and R8 is the curvature radius of the image side of the fourth lens.

[0035] On the basis of the above technical solution, preferably, the optical objective lens group satisfies the following relationship:

[0036] 0.85≤T2 / T3≤1.2;

[0037] Wherein, T2 is the thickness of the second lens on the optical axis, and T3 is the thickness of the third lens on the optical axis.

[0038] On the basis of the above technical solution, preferably, the optical objective lens group satisfies the following relationship:

[0039] 1.1≤T5 / T6≤1.7;

[0040] Wherein, T5 is the thickness of the fifth lens on the optical axis, and T6 is the thickness of the sixth lens on the optical axis.

[0041] On the basis of the above technical solution, preferably, the optical objective lens group satisfies the following relationship:

[0042] 0.01≤T6 / TTL≤0.03;

[0043] Wherein, T6 is the thickness of the sixth lens on the optical axis, and TTL is the total system length of the optical objective lens group.

[0044] On the other hand, the present invention provides a capsule endoscope, comprising the above-mentioned optical objective lens group, and also comprising a housing, a lighting module, an image sensor, a control module, a power module and a wireless transmission module, wherein:

[0045] The housing is used to encapsulate the optical lens group, the lighting module, the image sensor, the control module, the power module and the wireless transmission module;

[0046] The optical objective lens group, the image sensor, the control module, the power module and the wireless transmission module are sequentially arranged in the housing;

[0047] The lighting module is arranged on the side of the optical objective lens group;

[0048] The lighting module, the image sensor, the control module and the wireless transmission module are all electrically connected to the power module, and the lighting module, the image sensor and the wireless transmission module are all electrically connected to the control module.

[0049] The optical objective lens set and capsule endoscope of the present invention have the following beneficial effects compared with the prior art:

[0050] (1) By reasonably controlling the lens shape, optical power and related parameter relationships, the optical objective lens group can well correct chromatic aberration, astigmatism, coma, field curvature and distortion, so that it has the advantages of miniaturization, large field of view and high imaging quality, which is convenient for application in micro devices;

[0051] (2) The capsule endoscope of the present invention, by applying the above-mentioned optical objective lens group, can have a smaller diameter, so that it can pass through the pylorus, the narrowest part of the human intestine, and the small intestine with a diameter of 15 to 25 mm, and ensure good observation effects, which greatly improves the convenience of application and ensures the imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 is an optical structure diagram of the first embodiment of the optical objective lens assembly of the present invention;

[0054] Figure 2 is a point diagram in the first embodiment of the optical objective lens assembly of the present invention;

[0055] Figure 3 is a field curvature / distortion diagram of the first embodiment of the optical objective lens assembly of the present invention;

[0056] Figure 4 is an MTF diagram of the first embodiment of the optical objective lens assembly of the present invention;

[0057] Figure 5 is an optical structure diagram of the second embodiment of the optical objective lens assembly of the present invention;

[0058] Figure 6 is a point diagram in the second embodiment of the optical objective lens assembly of the present invention;

[0059] Figure 7 is a field curvature / distortion diagram in the second embodiment of the optical objective lens assembly of the present invention;

[0060] Figure 8 is an MTF diagram of the second embodiment of the optical objective lens assembly of the present invention;

[0061] Fig. 9 is a structural diagram of a capsule endoscope of the present invention;

[0062] In the figure: 1, housing; 2, lighting module; 3, image sensor; 4, control module; 5, power module; 6, wireless transmission module; 7, support assembly; 8, switch; 100, optical objective lens group;

[0063] L1, first lens; L2, second lens; ST, aperture; L3, third lens; L4, fourth lens; L5, fifth lens; L6, sixth lens. DETAILED DESCRIPTION

[0064] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0065] like Figure 1 and Figure 5 As shown, the optical objective lens group of the present invention includes a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5 and a sixth lens L6;

[0066] like Fig. 9 As shown, the capsule endoscope of the present invention includes the above-mentioned optical objective lens group, and also includes a housing 1, a lighting module 2, an image sensor 3, a control module 4, a power module 5, a wireless transmission module 6, a support assembly 7, a switch 8 and an optical objective lens group 100.

[0067] The housing 1 is used to encapsulate the optical lens group, the lighting module 2, the image sensor 3, the control module 4, the power module 5 and the wireless transmission module 6; the optical lens group, the image sensor 3, the control module 4, the power module 5 and the wireless transmission module 6 are arranged in the housing 1 in sequence;

[0068] Wherein, the lighting module 2 is arranged on the side of the optical objective lens group;

[0069] The lighting module 2 is used to provide a light source to provide sufficient illumination, thereby ensuring the clarity of the image.

[0070] The lighting module 2, the image sensor 3, the control module 4 and the wireless transmission module 6 are all electrically connected to the power module 5, and the power module 5 provides electrical energy to each electrical component;

[0071] The lighting module 2 , the image sensor 3 and the wireless transmission module 6 are all electrically connected to the control module 4 so as to be centrally controlled by the control module 4 .

[0072] In this structure, the optical objective lens group is used to gather and guide the light to enter the image sensor 3.

[0073] The image sensor 3 is used to convert the optical signal into an electrical signal to form a digital image.

[0074] The control module 4 is used to convert the digital image into data that can be transmitted wirelessly;

[0075] Specifically, the control module 4 converts the collected digital image signal into a serial data stream, or encodes the digital image into a standard image data format, such as JPEG, PNG, etc., and then transmits it.

[0076] The wireless transmission module 6 is used to receive data from the control module 4 and transmit the data to the outside world;

[0077] Specifically, the wireless transmission module can use Wifi communication or Bluetooth communication to perform wireless data transmission.

[0078] Specifically, the control module 4 has various functions, such as being used for signal processing, data transmission and control, which is a conventional configuration of a sensor.

[0079] Furthermore, the capsule endoscope is also provided with a support assembly 7 and a switch 8, such as Fig. 9 As shown, in the figure, 100 represents the optical objective lens assembly of the present invention;

[0080] When the structure is arranged, the optical objective lens group 100 is arranged on one side of the image sensor 3 with the support component 7, and the lighting module 2 is arranged at the end of the support component 7 away from the image sensor 3 to perform fill light work.

[0081] The switch 8 is used for start and stop control of the capsule endoscope, and is mainly used for controlling the on and off of the energy supply circuit of the power module 5 .

[0082] The embodiments of the optical objective lens assembly of the present invention are as follows:

[0083] Embodiment 1:

[0084] like Figures 1 to 8 As shown, the optical objective lens group of the present invention comprises, from the object side to the image side, a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5 and a sixth lens L6, wherein:

[0085] The first lens L1 has negative refractive power, and the object side of the first lens L1 is a flat surface;

[0086] The second lens L2 has positive refractive power, and the second lens L2 is a biconvex lens;

[0087] The third lens L3 has positive refractive power, and is a biconvex lens;

[0088] The fourth lens L4 has negative refractive power, and the fourth lens L4 is a biconcave lens;

[0089] The fifth lens L5 has positive refractive power, and is a meniscus lens with a convex surface facing the object side;

[0090] The sixth lens L6 has positive refractive power;

[0091] The optical objective lens group satisfies the following relationship:

[0092] -1.7≤f1 / F≤-1.6;

[0093] 0.95≤T1 / F≤1.15;

[0094] 1.1≤V1 / V6≤1.2;

[0095] Wherein, f1 is the focal length of the first lens L1; F is the focal length of the optical objective lens group; T1 is the thickness of the first lens L1 on the optical axis, V1 is the Abbe number of the first lens L1, and V6 is the Abbe number of the sixth lens L6;

[0096] By controlling the above parameters, the optical objective lens group can well correct chromatic aberration, astigmatism, field curvature and distortion to ensure good imaging quality;

[0097] At the same time, the aperture ST is arranged on the object side of the third lens L3, so it is easy to correct various aberrations and to control the angle of the high image highlight light when it enters the imaging element;

[0098] Specifically, the first lens L1 is used to correct aberrations, coma, astigmatism, field curvature and distortion;

[0099] The second lens L2 is used to correct chromatic aberration, astigmatism, field curvature and distortion;

[0100] The third lens L3 is used to correct astigmatism, field curvature and distortion;

[0101] The fourth lens L4 is used to correct coma, astigmatism, field curvature and distortion;

[0102] The fifth lens L5 is used to correct chromatic aberration, astigmatism, field curvature and distortion;

[0103] The sixth lens L6 is used to correct chromatic aberration, astigmatism, field curvature and distortion;

[0104] The optical objective lens group satisfies the following relationship:

[0105] 1.9≤f1 / f4≤2.0;

[0106] Wherein, f1 is the focal length of the first lens L1, and f4 is the focal length of the fourth lens L4;

[0107] The optical objective lens assembly can effectively control the aberration of the system by controlling the above parameters.

[0108] The optical objective lens group satisfies the following relationship:

[0109] -0.6≤(R3+R4) / (R3-R4)≤-0.2;

[0110] Wherein, R3 is the curvature radius of the object side surface of the second lens L2, and R4 is the curvature radius of the image side surface of the second lens L2;

[0111] The optical objective lens group can well correct coma, astigmatism and distortion by controlling the above parameters.

[0112] The optical objective lens group satisfies the following relationship:

[0113] 3≤V1-V2≤9;

[0114] Wherein, V1 is the Abbe number of the first lens L1, and V2 is the Abbe number of the second lens L2;

[0115] The optical objective lens assembly can effectively control the chromatic aberration of the system by controlling the above parameters.

[0116] The optical objective lens group satisfies the following relationship:

[0117] 35≤V3-V4≤40;

[0118] Wherein, V3 is the Abbe number of the third lens L3, and V4 is the Abbe number of the fourth lens L4;

[0119] The optical objective lens assembly can effectively control the chromatic aberration of the system by controlling the above parameters.

[0120] The optical objective lens group satisfies the following relationship:

[0121] -1.0≤(R7+R8) / (R7-R8)≤-0.8;

[0122] Wherein, R7 is the curvature radius of the object side surface of the fourth lens L4, and R8 is the curvature radius of the image side surface of the fourth lens L4;

[0123] The optical objective lens group can well correct coma, astigmatism and distortion by controlling the above parameters.

[0124] The optical objective lens group satisfies the following relationship:

[0125] 0.85≤T2 / T3≤1.2;

[0126] Wherein, T2 is the thickness of the second lens L2 on the optical axis, and T3 is the thickness of the third lens L3 on the optical axis;

[0127] The optical objective lens group can correct aberration well by controlling the above parameters.

[0128] The optical objective lens group satisfies the following relationship:

[0129] 1.1≤T5 / T6≤1.7;

[0130] Wherein, T5 is the thickness of the fifth lens L5 on the optical axis, and T6 is the thickness of the sixth lens L6 on the optical axis;

[0131] The optical objective lens group can correct aberration well by controlling the above parameters.

[0132] The optical objective lens group satisfies the following relationship:

[0133] 0.01≤T6 / TTL≤0.03;

[0134] Wherein, T6 is the thickness of the sixth lens L6 on the optical axis, and TTL is the total system length of the optical objective lens assembly;

[0135] The optical objective lens group can well correct coma, astigmatism, field curvature and distortion by controlling the above parameters.

[0136] In this embodiment, the sixth lens L6 is a meniscus lens with a convex surface facing the object side. Figure 1 As shown;

[0137] The design parameters of the optical objective lens group in this embodiment are shown in Table 1:

[0138] Table 1:

[0139]

[0140] The optical performance of the optical objective lens assembly of this embodiment is as follows: Figures 2 to 4 As shown, from the spot diagram, field curvature / distortion diagram, and MTF diagram, it can be seen that the relevant data all meet the design requirements and each aberration has been well corrected;

[0141] The maximum field of view of the optical objective lens group of this embodiment reaches 150°, which has an ultra-wide angle and is conducive to observation while ensuring the imaging quality.

[0142] Embodiment 2:

[0143] The difference between this embodiment and the first embodiment is that the sixth lens L6 is a meniscus lens with a convex surface facing the image side. Figure 5 As shown;

[0144] The design parameters of the optical objective lens group in this embodiment are shown in Table 2:

[0145] Table 2:

[0146]

[0147]

[0148] The optical performance of the optical objective lens assembly of this embodiment is as follows: Figures 6 to 8 As shown in the figure, it can be seen from the spot diagram, field curvature / distortion diagram, and MTF diagram that the relevant data all meet the design requirements and each aberration has been well corrected;

[0149] The maximum field of view of the optical objective lens group of this embodiment reaches 150°, which has an ultra-wide angle and is conducive to observation while ensuring the imaging quality.

[0150] The values ​​of the relational expressions of the optical objective lens assembly in the first embodiment and the second embodiment are shown in Table 3:

[0151] Table 3:

[0152] Relational Embodiment 1 Embodiment 2 f1 / F -1.65 -1.61 T1 / F 1.12 1.02 V1 / V6 1.18 1.16 f1 / f4 1.92 1.98 (R3+R4) / (R3-R4) -0.55 -0.31 V1-V2 7.9 3.9 V3-V4 38.8 38.8 (R7+R8) / (R7-R8) -0.85 -0.90 T2 / T3 1.12 0.90 T5 / T6 1.63 1.20 T6 / TTL 0.02 0.02

[0153] Wherein, f1 is the focal length of the first lens L1; f4 is the focal length of the fourth lens L4; F is the focal length of the entire lens; T1 is the thickness of the first lens L1 on the optical axis, T2 is the thickness of the second lens L2 on the optical axis, T3 is the thickness of the third lens L3 on the optical axis, T5 is the thickness of the fifth lens L5 on the optical axis, T6 is the thickness of the sixth lens L6 on the optical axis, V1 is the Abbe number of the first lens L1, V2 is the Abbe number of the second lens L2, V3 is the Abbe number of the third lens L3, V4 is the Abbe number of the fourth lens L4, V6 is the Abbe number of the sixth lens L6, TTL is the total system length of the optical objective lens group, R3 is the radius of curvature of the object side surface of the second lens L2, R4 is the radius of curvature of the image side surface of the second lens L2, R7 is the radius of curvature of the object side surface of the fourth lens L4, and R8 is the radius of curvature of the image side surface of the fourth lens L4.

[0154] The capsule endoscope of the present invention, by applying the above-mentioned optical objective lens group, can have a smaller diameter, so that it can pass through the narrowest pylorus of the human intestine and the small intestine with a diameter of 15 to 25 mm, and ensure good observation effects, greatly improving the convenience of application and ensuring imaging quality.

[0155] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An optical objective lens assembly, characterized in that: The optical objective lens group is composed of the following components, which are, from the object side to the image side, a first lens, a second lens, an aperture, a third lens, a fourth lens, a fifth lens and a sixth lens, wherein: The first lens has negative optical power, and the object side of the first lens is a flat surface; The second lens has positive optical power, and the second lens is a biconvex lens; The third lens has positive optical power, and the third lens is a biconvex lens; The fourth lens has negative optical power, and the fourth lens is a biconcave lens; The fifth lens has positive power, and is a meniscus lens with a convex surface facing the object side; The sixth lens has positive optical power; The optical objective lens group satisfies the following relationship: -1.7≤f1 / F≤-1.6; 0.95≤T1 / F≤1.15; 1.1≤V1 / V6≤1.2; Among them, f1 is the focal length of the first lens; F is the focal length of the optical objective lens group; T1 is the thickness of the first lens on the optical axis, V1 is the Abbe number of the first lens, and V6 is the Abbe number of the sixth lens.

2. The optical objective lens assembly according to claim 1, characterized in that: The optical objective lens group satisfies the following relationship: 1.9≤f1 / f4≤2.0; Wherein, f1 is the focal length of the first lens, and f4 is the focal length of the fourth lens.

3. The optical objective lens assembly according to claim 1, characterized in that: The optical objective lens group satisfies the following relationship: -0.6≤(R3+R4) / (R3-R4)≤-0.2; Among them, R3 is the curvature radius of the object side of the second lens, and R4 is the curvature radius of the image side of the second lens.

4. The optical objective lens assembly according to claim 1, characterized in that: The optical objective lens group satisfies the following relationship: 3≤V1-V2≤9; Wherein, V1 is the Abbe number of the first lens, and V2 is the Abbe number of the second lens.

5. The optical objective lens assembly according to claim 1, characterized in that: The optical objective lens group satisfies the following relationship: 35≤V3-V4≤40; Wherein, V3 is the Abbe number of the third lens, and V4 is the Abbe number of the fourth lens.

6. The optical objective lens assembly according to claim 1, characterized in that: The optical objective lens group satisfies the following relationship: -1.0≤(R7+R8) / (R7-R8)≤-0.8; Among them, R7 is the curvature radius of the object side of the fourth lens, and R8 is the curvature radius of the image side of the fourth lens.

7. The optical objective lens assembly according to claim 1, characterized in that: The optical objective lens group satisfies the following relationship: 0.85≤T2 / T3≤1.2; Wherein, T2 is the thickness of the second lens on the optical axis, and T3 is the thickness of the third lens on the optical axis.

8. The optical objective lens assembly according to claim 1, characterized in that: The optical objective lens group satisfies the following relationship: 1.1≤T5 / T6≤1.7; Wherein, T5 is the thickness of the fifth lens on the optical axis, and T6 is the thickness of the sixth lens on the optical axis.

9. The optical objective lens assembly according to claim 1, characterized in that: The optical objective lens group satisfies the following relationship: 0.01≤T6 / TTL≤0.03; Wherein, T6 is the thickness of the sixth lens on the optical axis, and TTL is the total system length of the optical objective lens assembly.

10. A capsule endoscope, characterized in that: The optical objective lens assembly comprises the optical objective lens assembly as claimed in any one of claims 1 to 9, and further comprises a housing (1), an illumination module (2), an image sensor (3), a control module (4), a power module (5) and a wireless transmission module (6), wherein: The housing (1) is used to encapsulate the optical objective lens group, the lighting module (2), the image sensor (3), the control module (4), the power module (5) and the wireless transmission module (6); The optical objective lens group, the image sensor (3), the control module (4), the power module (5) and the wireless transmission module (6) are arranged in sequence inside the housing (1); The lighting module (2) is arranged on the side of the optical objective lens assembly; The lighting module (2), the image sensor (3), the control module (4) and the wireless transmission module (6) are all electrically connected to the power module (5), and the lighting module (2), the image sensor (3) and the wireless transmission module (6) are all electrically connected to the control module (4).

Images