Optical imaging module of endoscope
By using an endoscope optical imaging module with an anti-long-range structure, combined with negative-positive power lenses and a beam splitter, the problem of defocusing in close-up and distant imaging of traditional endoscope optical systems is solved, achieving high-definition imaging and miniaturization.
Patent Information
- Application Number
- CN202423205488.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-12-25
AI Technical Summary
Traditional endoscopic optical systems are prone to defocusing when imaging near and far objects, and existing focusing methods are complex and costly, making it difficult to meet the requirements of miniaturization and high resolution.
The endoscope optical imaging module with a reverse telescopic structure includes a negative power lens, a plano-convex lens, an aperture stop, a cemented doublet lens group, and a beam splitter. By combining negative and positive power lenses and using the beam splitter to split the light, the difference in the interval between the two image planes is controlled, aberrations and distortions are corrected, and high-definition imaging is achieved.
While meeting the requirements of miniaturization and wide spectrum, the imaging quality of near and far scenes has been improved, the assembly and control difficulty has been reduced, and high-definition imaging with a field of view of not less than 90° has been achieved.
Smart Images
Figure CN223526570U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to an optical imaging module, in particular to an endoscope optical imaging module, belongs to optical imaging technical field. BACKGROUND
[0002] Endoscope has the indispensable role in medical diagnosis and industrial detection, for example is applied to clinical examination intra-abdominal disease and treatment can carry out careful observation to the tissue structure of the lesion surface, and under the direct vision takes the material or positioning, has improved the accuracy of intra-abdominal disease diagnosis greatly. With the popularization of medical endoscope in clinical application, people's requirement to endoscope is higher and higher, smaller outer diameter can reduce the patient's pain and postoperative recovery time, especially in 3D endoscope optical system, the diameter of monocular endoscope has strict requirement. The current traditional fixed focus endoscope depth of field is invariable and cannot be expanded, and the focusing mode has higher requirement to electromechanical.
[0003] For fixed focus optical system, after the aperture and focal length are fixed, when actually shooting the object, due to the very short shooting working distance, the change of object distance causes the corresponding conjugate relationship to result in significant change of image distance, if the image plane position is not compensated (in actual application, CCD and CMOS will be glued and solidified with the lens), then virtual focus will be generated, and the imaging quality will decrease linearly. The traditional improvement method is to compensate by optical zoom or to realize system overall zooming by piezoelectric control of lens deformation to improve the virtual focus problem caused by near and far scene image planes. But optical zoom compensation needs to cooperate with motor and cam structure components, so that the overall structure is large, the piezoelectric control of lens deformation has higher requirement to the material of lens, and the technical cost and reliability requirement are higher. SUMMARY
[0004] The utility model aims at: provide a kind of endoscope optical imaging module, which can realize that the field of view angle is not less than 90 °, the wave band range 0.45-0.86um high-definition imaging, to improve the imaging quality of near end and far end of working distance, while meeting the miniaturization of wide spectrum, reduce the difficulty of assembly and control.
[0005] To achieve the above purpose, the technical scheme of the utility model is as follows: an endoscope optical imaging module, the innovation point of which is that the optical imaging module is a reverse telephoto structure, and includes a negative focal length lens, a plano-convex lens, an aperture stop, a double-cemented lens group, a positive focal length lens and a light splitting prism arranged along the direction of light propagation,
[0006] The concave surface of the negative focal length lens is located on the plane side of the plano-convex lens, the aperture stop is arranged between the convex surface of the plano-convex lens and the concave surface of the double-cemented lens group, the convex surface of the double-cemented lens group is arranged opposite to the convex surface of the positive focal length lens, and the light splitting prism is located outside the concave surface of the positive focal length lens,
[0007] The light-splitting prism has two image planes 1 and 2, one of which is the image plane of the far view after focusing by the optical imaging module, and the other is the image plane of the near view after focusing by the optical imaging module.
[0008] In the above technical solution, the double-cemented lens group is integrated by a negative-power lens and a positive-power lens, the convex surface of the negative-power lens is integrated with the concave surface of the positive-power lens, the concave surface of the negative-power lens is adjacent to the aperture stop, and the convex surface of the positive-power lens is arranged opposite to the convex surface of the positive-power lens.
[0009] In the above technical solution, the negative-power lens and the positive-power lens are integrated by ultraviolet glue or epoxy resin glue.
[0010] In the above technical solution, the focal length f1 of the negative-power lens satisfies -3mm≤f1≤-2mm, the focal length f2 of the plano-convex lens satisfies 3mm≤f2≤6mm, and the focal length f5 of the positive-power lens satisfies 4mm≤f5≤17mm.
[0011] In the above technical solution, the focal length f3 of the negative-power lens satisfies -6mm≤f3≤-20mm, and the focal length f4 of the positive-power lens satisfies 3mm≤f4≤8mm.
[0012] The endoscope optical imaging module has the following positive effects: the optical imaging module is a reverse telephoto structure, and includes a negative-power lens, a plano-convex lens, an aperture stop, a double-cemented lens group, a positive-power lens and a light-splitting prism arranged along the light propagation direction,
[0013] The concave surface of the negative-power lens is located on the plane side of the plano-convex lens, the aperture stop is arranged between the convex surface of the plano-convex lens and the concave surface of the double-cemented lens group, the convex surface of the double-cemented lens group is arranged opposite to the convex surface of the positive-power lens, and the light-splitting prism is located outside the concave surface of the positive-power lens,
[0014] The light-splitting prism has two image planes 1 and 2, one of which is the image plane of the far view after focusing by the optical imaging module, and the other is the image plane of the near view after focusing by the optical imaging module.
[0015] The utility model discloses a negative power lens compresses field angle angle, through the combination of multiple different positive and negative power lenses to correct the aberration and distortion of optical system, finally through the light splitting of light splitting prism, the imaging of two CCDs or CMOSs with different distances, the imaging quality of near and far ends of working distance is improved through the interval difference of two image planes, thereby the original depth of field is expanded, the assembly and control difficulty are reduced while meeting the miniaturization of wide spectrum, the utility model discloses can realize the high definition imaging of field angle full angle not less than 90 degrees, and wave band range 0.45-0.86um. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 It is a structure schematic diagram of a specific embodiment of the utility model,
[0017] Figure 2 It is the MTF curve diagram of image surface 1 of the utility model at working distance 200mm,
[0018] Figure 3 It is the MTF curve diagram of image surface 1 of the utility model at working distance 100mm,
[0019] Figure 4 It is the MTF curve diagram of image surface 1 of the utility model at working distance 50mm,
[0020] Figure 5 It is the MTF curve diagram of image surface 1 of the utility model at working distance 20mm,
[0021] Figure 6 It is the MTF curve diagram of image surface 1 of the utility model at working distance 10mm,
[0022] Figure 7 It is the MTF curve diagram of image surface 2 of the utility model at working distance 10mm,
[0023] Figure 8 It is the MTF curve diagram of image surface 1 of the utility model at working distance 6mm,
[0024] Figure 9 It is the MTF curve diagram of image surface 2 of the utility model at working distance 6mm. DETAILED DESCRIPTION
[0025] The utility model is further explained below in connection with the drawings and the embodiments given, but is not limited to this.
[0026] As Figure 1 , 2, 3, 4, 5, 6, 7, 8, 9, an endoscope optical imaging module, the optical imaging module is a reverse distance structure, and includes a negative focal length lens 1, a plano-convex lens 2, an aperture diaphragm 3, a double cemented lens group, a positive focal length lens 6 and a light splitting prism 7 arranged along the light propagation direction,
[0027] The concave surface of the negative focal length lens 1 is located on the plane side of the plano-convex lens 2, the aperture diaphragm 3 is arranged between the convex surface of the plano-convex lens 2 and the concave surface of the double cemented lens group, the convex surface of the double cemented lens group is arranged opposite to the convex surface of the positive focal length lens 6, and the light splitting prism 7 is located outside the concave surface of the positive focal length lens 6,
[0028] The light splitting prism 7 has image planes 1 and 2 with different distances, one of which is the image plane after the optical imaging module focuses on the far view, and the other is the image plane after the optical imaging module focuses on the near view, and the position difference between the two image planes is controlled by the thickness of the light splitting prism.
[0029] Further, as shown in Figure 1 In order to further improve the aberration and distortion of the optical system, the double cemented lens group is integrated by a negative focal length lens 4 and a positive focal length lens 5, the convex surface of the negative focal length lens 4 is integrated with the concave surface of the positive focal length lens 5, the concave surface of the negative focal length lens 4 is adjacent to the aperture diaphragm 3, and the convex surface of the positive focal length lens 5 is arranged opposite to the convex surface of the positive focal length lens 6. Specifically, the field angle is compressed by the negative focal length lens 1, and the aberration and distortion of the optical system are corrected by the combination of the multiple lenses with negative-positive-negative-positive-positive focal lengths.
[0030] Further, as shown in Figure 1 In order to make the structure more reasonable, the negative focal length lens 4 and the positive focal length lens 5 are integrated by ultraviolet glue or epoxy resin glue.
[0031] Further, the focal length f1 of the negative focal length lens 1 satisfies -3mm≤f1≤-2mm, the focal length f2 of the plano-convex lens 2 satisfies 3mm≤f2≤6mm, and the focal length f5 of the positive focal length lens 6 satisfies 4mm≤f5≤17mm.
[0032] Further, the focal length f3 of the negative focal length lens 4 satisfies -6mm≤f3≤-20mm, and the focal length f4 of the positive focal length lens 5 satisfies 3mm≤f4≤8mm.
[0033] As shown in Figures 2-9The MTF curve diagram of two different spaced image planes or detectors at different working distances is shown, the image plane 2 of the close-range object formed by the optical system, the transmission function MTF imaging quality of the image plane 1 is obviously improved at the close distance 6-20mm, when working at close range, the image plane is switched to the image plane 2, the image quality is improved, so that greater magnification is obtained at the expanded close-end working distance, and the details of the lesion tissue are presented more specifically, and the advantages of high resolution of the endoscope are fully exerted.
[0034] The utility model discloses a negative power lens compression field angle angle, through the lens combination of power negative-positive-negative-positive-positive, corrects the aberration and distortion of optical system, finally through the light splitting prism, by two distance inequality's CCD or CMOS imaging, through the interval difference of two image planes to improve the imaging quality of working distance near end and far end, thereby expands the original depth of field, satisfies the miniaturization of wide spectrum, and reduced the assembly and control difficulty, the utility model discloses can realize field angle full angle not less than 90 DEG, and the high definition imaging of wave band range 0.45-0.86um.
[0035] The above-mentioned ideal embodiments according to the utility model are used as inspiration, through the above-mentioned description, relevant staff can make various changes and modifications without deviating from the technical idea of the utility model. The technical scope of the utility model is not limited to the content in the specification, and must be determined according to the scope of claims.
Claims
1. An endoscopic optical imaging module, characterized by: The optical imaging module is a reverse telephoto structure, and comprises a negative focal length lens (1), a plano-convex lens (2), an aperture diaphragm (3), a doublet lens group, a positive focal length lens (6) and a light splitting prism (7) arranged along the light propagation direction, The concave surface of the negative focal length lens (1) is located on the plane side of the plano-convex lens (2), the aperture diaphragm (3) is arranged between the convex surface of the plano-convex lens (2) and the concave surface of the doublet lens group, the convex surface of the doublet lens group is arranged opposite to the convex surface of the positive focal length lens (6), and the light splitting prism (7) is located outside the concave surface of the positive focal length lens (6). The light splitting prism (7) has an image surface 1 and an image surface 2, one of which is the image surface of the far scene after focusing by the optical imaging module, and the other is the image surface of the near scene after focusing by the optical imaging module.
2. The endoscopic optical imaging module of claim 1, wherein: The doublet lens group is integrated by a negative focal length lens (4) and a positive focal length lens (5), the convex surface of the negative focal length lens (4) is integrated with the concave surface of the positive focal length lens (5), the concave surface of the negative focal length lens (4) is adjacent to the aperture diaphragm (3), and the convex surface of the positive focal length lens (5) is arranged opposite to the convex surface of the positive focal length lens (6).
3. The endoscopic optical imaging module of claim 2, wherein: The negative focal length lens (4) and the positive focal length lens (5) are integrated by ultraviolet glue or epoxy resin glue.
4. The endoscopic optical imaging module of claim 1, wherein: The focal length f1 of the negative focal length lens (1) satisfies -3mm≤f1≤-2mm, the focal length f2 of the plano-convex lens (2) satisfies 3mm≤f2≤6mm, and the focal length f5 of the positive focal length lens (6) satisfies 4mm≤f5≤17mm.
5. The endoscopic optical imaging module of claim 2, wherein: The focal length f3 of the negative power lens (4) satisfies -6mm ≤ f3 ≤ -20mm, and the focal length f4 of the positive power lens (5) satisfies 3mm ≤ f4 ≤ 8mm 。