CN114176484A

CN114176484A - Polarized light endoscope device, camera and camera optical system

Info

Publication number: CN114176484A
Application number: CN202111545723.6A
Authority: CN
Inventors: 郭毅军; 刘剑
Original assignee: Chongqing Xishan Science and Technology Co Ltd
Current assignee: Chongqing Xishan Science and Technology Co Ltd
Priority date: 2021-12-16
Filing date: 2021-12-16
Publication date: 2022-03-15
Also published as: WO2023108982A1

Abstract

The invention mainly discloses a polarized light endoscope device camera optical system, which comprises an optical adapter and a light splitter which are axially arranged in sequence from an object side to an image side; the optical splitter has the optical characteristics of selecting the wavelength of light waves into two wave bands of 380 nm-lambda and lambda-700 nm, reflecting the light waves with the wavelength of 380 nm-lambda and transmitting the light waves with the wavelength of lambda-700 nm, or transmitting the light waves with the wavelength of 380 nm-lambda and reflecting the light waves with the wavelength of lambda-700 nm; lambda is any value within the range of 600nm to 670 nm. After the light waves are split, light waves with the wavelength of 380 nm-lambda are imaged on the white light image sensor, light waves with the wavelength of lambda-700 nm are imaged on the polarized light image sensor, the polarized light endoscope device can simultaneously acquire common white light images and polarized light images in the operation, the polarized light imaging can provide clearer images, the operation visual field in the operation is kept continuous and clear, and the safety and the effectiveness of the operation are improved.

Description

Polarized light endoscope device, camera and camera optical system

Technical Field

The invention relates to the technical field of endoscopes, in particular to a polarized light endoscope device.

Background

The medical endoscope is a medical electronic optical instrument which can be inserted into human body cavity and internal organ cavity to make direct observation, diagnosis and treatment, and is characterized by that it adopts optical lens with very small size to make optical imaging of intracavity object to be observed by means of miniature objective lens imaging system, then the optical imaging is sent to image processing main machine, and finally the observed image after image processing is outputted on the display screen for doctor to observe and diagnose.

Referring to fig. 1, a conventional endoscope apparatus includes a light source, an endoscope, a camera, and a main unit. The optical system of the camera generally includes an optical adaptive lens, which is divided into a fixed focal length adapter (i.e., an optical fixed focus adapter) and a variable focal length adapter (i.e., an optical zoom adapter), and a mechanical structure supporting the adapters. After the endoscope is connected with the eyepiece of the endoscope through the eyepiece connecting module, the image information of the endoscope is imaged to an image sensor at the rear end through an optical adapter and is displayed on a display in an enlarged mode.

The phenomenon of scattering of light is a phenomenon in which a part of light propagates in a direction deviated from the original direction when the light passes through an inhomogeneous medium, and the light deviated from the original direction is called scattered light. Scattered light can affect the image sharpness, causing blurring of the target and even failure of the target to detect. In clinical operations (such as orthopedic operations, urinary surgery operations, gynecological operations and the like) using the endoscope device, the operation cavity is filled with physiological saline, blood, bone residues, soft tissue residues, stone particles and the like under the medium of the physiological saline, and the substances form a non-uniform medium, so that reflected light of the medium can be scattered, and the imaging definition of the endoscope device is influenced. In this case, the prior art camera optical system for an endoscope device cannot solve the above problems, which results in blurred surgical field and affects the safety and effectiveness of the surgery. Whether the scattered light in the inhomogeneous medium can be effectively inhibited or not and the field definition in the operation is improved becomes more important.

Disclosure of Invention

The endoscope mainly solves the technical problem of reducing the interference of environmental factors in the operation and enabling the endoscope device to output clearer images.

Accordingly, an embodiment of the present invention provides a polarized light endoscope apparatus camera optical system including: the optical adapter and the optical splitter are arranged in sequence from the object side to the image side in the axial direction; the optical splitter has the optical characteristic of selecting the wavelength of light waves into two wave bands of 380 nm-lambda and lambda-700 nm, reflects the light waves with the wavelength of 380 nm-lambda and transmits the light waves with the wavelength of lambda-700 nm at the same time, or transmits the light waves with the wavelength of 380 nm-lambda and reflects the light waves with the wavelength of lambda-700 nm at the same time; the lambda is any value within the range of 600 nm-670 nm; the light wave with the wave band of 380 nm-lambda is used for common white light imaging, and the light wave with the wave band of lambda-700 nm is used for polarized light imaging.

In one embodiment, the optical adapter has a focal length of 27-35 mm and a reverse-to-far ratio of 1-1.5.

In an embodiment, in the optical system of the camera of the polarized light endoscope apparatus, the optical adapter includes a first lens group and a second lens group, which are arranged in order from an object side to an image side; the focal length of the first lens group is 15-25 nm; the focal length of the second lens group is 100-150 nm.

In one embodiment, the λ has a value of 635 nm.

In an embodiment, the camera optical system of a polarized light endoscope apparatus is characterized in that the first lens group comprises a first lens group double cemented lens and a first lens group positive lens, which are arranged in order from an object side to an image side in an axial direction; the second lens group comprises a first negative lens of the second lens group, a second negative lens of the second lens group, a positive lens of the second lens group and a double-cemented lens of the second lens group, and the double-cemented lenses are sequentially and axially sealed from the object side to the image side.

In one embodiment, the optical system of the camera of the polarized light endoscope device comprises two right-angle prisms bonded with each other, and the light splitting surfaces of the two right-angle prisms have optical characteristics for selecting the wavelength of the light wave to be divided into two wave bands of 380 nm-lambda and lambda-700 nm.

Meanwhile, an embodiment of the present invention provides a camera for a polarized light endoscope apparatus, including a white light image sensor; the endoscope device also comprises a polarized light image sensor and a polarized light endoscope device camera optical system with any technical characteristics; the 380 nm-lambda wave band light wave is imaged on the white light image sensor, and the lambda-700 nm wave band light wave is imaged on the polarized light image sensor.

Further, an embodiment of the present invention provides a polarized light endoscope apparatus including the above-described technical features.

According to the polarized light endoscope device of the embodiment, the optical adapter is effectively matched with the optical splitter, the optical signal transmitted by the optical adapter is divided into two parts by the optical splitter, one part of the optical signal is imaged on the white light image sensor, the other part of the optical signal is imaged on the polarized light image sensor, and the ordinary white light image and the polarized light image in the operation can be simultaneously obtained and are mutually complementary. Under the condition of fuzzy environment in the operation, the polarized light imaging can provide clearer images and larger detection depth, and the functions of blood penetration, bone residue penetration and the like are realized, so that scattered light in a non-uniform medium can be effectively inhibited, the operation visual field in the operation is kept to be continuously clear, and the safety and the effectiveness of the operation are greatly improved.

Drawings

FIG. 1 is a schematic view of an endoscopic device of the prior art;

FIG. 2 is a schematic diagram of a polarized light endoscope apparatus according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an optical system of a camera of a polarized light endoscope apparatus according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of an optical adapter in an optical system of a camera of a polarized light endoscope apparatus according to an embodiment of the present invention;

FIG. 5 is a graph of the Modulation Transfer Function (MTF) of the optical adapter of FIG. 4 in accordance with the present invention;

FIG. 6 is a schematic structural diagram of a beam splitter in an optical system of a camera of a polarized light endoscope apparatus according to an embodiment of the present invention;

FIG. 7 is a schematic view of the beam splitting mode of the beam splitter in the optical system of the camera of the polarized light endoscope apparatus according to an embodiment of the present invention;

FIG. 8 is a schematic view of the beam splitting pattern of the beam splitter in the optical system of the camera of the polarized light endoscope apparatus according to an embodiment of the present invention;

fig. 9 is a schematic view of a beam splitting mode of a beam splitter in an optical system of a camera of a polarized light endoscope apparatus according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the following detailed description and accompanying drawings. Wherein like elements in different embodiments are numbered with like associated elements. In the following description, numerous details are set forth in order to provide a better understanding of the present application. However, those skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in detail in order to avoid obscuring the core of the present application from excessive description, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.

Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. Also, the various steps or actions in the method descriptions may be transposed or transposed in order, as will be apparent to one of ordinary skill in the art. Thus, the various sequences in the specification and drawings are for the purpose of describing certain embodiments only and are not intended to imply a required sequence unless otherwise indicated where such sequence must be followed.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings).

In the present invention, the object side means a side of the lens closer to the object to be measured, and the image side means a side of the lens closer to the image plane. The lenses can be made of materials in the prior art, such as glass materials, crystal or organic glass. The symbol "-" represents the value range of a certain parameter, and the value range comprises two endpoint values; such as: the lambda of 600 nm-670 nm represents any value of 600 nm-670 nm, including two values of 600nm and 670 nm.

In an embodiment of the present invention, please refer to fig. 2 and fig. 3, fig. 2 is a schematic structural diagram of a polarized light endoscope apparatus, fig. 3 is a diagram of a camera optical system therein, which includes an optical adapter and an optical splitter, the optical splitter splits an optical signal transmitted from the optical adapter into two parts: selecting two wave bands of 380 nm-lambda and lambda-700 nm, reflecting light waves with the wavelength of 380 nm-lambda, transmitting light waves with the wavelength of lambda-700 nm, or transmitting light waves with the wavelength of 380 nm-lambda and reflecting light waves with the wavelength of lambda-700 nm; lambda is any value within the range of 600nm to 670 nm; light waves with wavelengths of 380nm to lambda are received by the white light image sensor 11, and light waves with wavelengths of lambda to 700nm are received by the polarized light image sensor 12. The positions of the white light image sensor 11 and the polarized light image sensor 12 are determined by the light splitter, namely the positions may be reversed according to the light splitting characteristics of the light splitter. The white light image sensor receives a common white light image, and the polarized light image sensor receives a polarized light image of a special spectrum.

In an embodiment of the present invention, referring to fig. 4, the optical system of the camera includes an optical fixed focus adapter, and the optical adapter includes a front protective sheet, a first lens group 10, a second lens group 20, and a rear protective sheet. The first lens group 10 and the second lens group 20 are fixed in relative position, and the whole can slightly move back and forth relative to the image sensor, so that the focusing and depth of field adjusting functions are achieved.

In an embodiment of the invention, the optical adapter of the present example has a focal length of 27 to 35mm, and a total length of 30 to 40mm (the total length is a distance between the front protection sheet and the rear protection sheet), and for adapting to the optical splitter, an inverse-distance ratio structure is adopted, and a ratio of a working distance L (i.e. a distance between the rear protection sheet and an image plane of the image sensor) and a focal length f of the optical adapter is an inverse-distance ratio, in the present example, the inverse-distance ratio is 1 to 1.5, and by matching the first lens group and the second lens group, an incident angle (CRA) of a principal ray is smaller than 15 degrees, and the principal ray is well matched with the image sensor at the rear end.

In an embodiment of the present invention, the first lens group 10 has a focal length of 15 to 25mm and a positive refractive power, and includes a first lens group cemented doublet 101 and a first lens group positive lens 102, which are arranged in order from an object side, and the first lens group cemented doublet is formed by a negative lens cemented with a positive lens.

In an embodiment of the present invention, the focal length of the second lens group 20 is 100-150 mm, and the second lens group has a positive focal power. Comprises a second lens group first negative lens 201, a second lens group second negative lens 202, a second lens group positive lens 203 and a second lens group double cemented lens 204; arranged in order from the object side. Wherein the second lens group double cemented lens is formed by cementing a negative lens and a positive lens; the first negative lens 201 of the second lens group, the second negative lens 202 of the second lens group and the positive lens 203 of the second lens group are assembled in a sealing way, so that the mechanical structure is simplified, the total length of the optical adapter is compact, and the miniaturization is facilitated.

The Modulation Transfer Function (MTF) curve is an important index for the imaging quality of an optical system. Referring to fig. 5, in the above embodiment, when the resolution of the optical adapter satisfies 220l p/mm, the full field contrast value is greater than 0.25, and is close to the diffraction limit, so that the imaging quality is better.

In an embodiment of the present invention, referring to fig. 6, the beam splitter of this embodiment is formed by gluing two right-angle prisms, and a splitting surface of the beam splitter is located between two inclined surfaces of the glued part, so that a part of incident light can be reflected and a part of incident light can be transmitted. As shown, the incident beam is split into a transmitted beam and a reflected beam after passing through the splitting plane. The light splitting surface is plated with a multi-layer medium optical film, in one embodiment, the multi-layer medium optical film can adopt a dichroic light filtering film to select the frequency of the light wave, namely, the wavelength of the light wave is selected, and the light wave is split into two wave bands of 380 nm-lambda and lambda-700 nm. Light beams with the wavelength of 380 nm-lambda are used for common white light imaging, light beams with the wavelength of lambda-700 nm are used for polarized light imaging, and the light beams are imaged on the white light image sensor 11 and the polarized light image sensor 12 respectively; the range of lambda is any value between 600nm and 670 nm.

In an embodiment of the present invention, the beam splitting surface is plated with a plurality of layers of materials with different refractive indexes, typically a high refractive index material film layer and a low refractive index material layer, which are sequentially stacked; the high refractive index material layer and the low refractive index material layer can be arranged on the inclined plane of any one of the right-angle prisms, or the high refractive index material layer can be arranged on the inclined plane of one of the right-angle prisms, and the low refractive index material layer can be arranged on the inclined plane of the other right-angle prism. The incident light angle of the light is 40-50 degrees, and the light with different wavelengths is transmitted and reflected by the material layer.

In an embodiment of the present invention, referring to fig. 7, the light splitting mode is light reflection with a wavelength of 380 to 635nm, the corresponding white light image sensor is used for common white light imaging, and light transmission with a wavelength of 635 to 700nm corresponds to polarized light image sensor for polarized light imaging. The value of lambda is 635nm, on one hand, the light wave range of white light is fully covered, and the reduction degree and the imaging quality of white light imaging are ensured; on the other hand, the polarized light in a sufficient wavelength range can be acquired, and the quality and clinical reference value of the polarized light imaging are ensured.

In an embodiment of the invention, referring to fig. 8, a high refractive index material layer and a low refractive index material layer are sequentially stacked, and a light splitting mode of the light splitter is light reflection with a wavelength of 600 to 700nm for polarized light imaging and light transmission with a wavelength of 380 to 600nm for common white light imaging.

In an embodiment of the invention, referring to fig. 9, the low refractive index material layer and the high refractive index material layer are sequentially stacked, and the light splitting mode of the light splitter is light transmission with a wavelength of 670-700 nm for polarized light imaging, and light reflection with a wavelength of 380-670 nm for common white light imaging.

In each embodiment of the invention, the ratio of the working distance L (namely the distance between the rear protection sheet and the image surface of the image sensor) to the focal length f is a reverse-to-far ratio, and the reverse-to-far ratio is 1-1.5 through the design of the large reverse-to-far ratio of the optical adapter, so that the optical adapter can be ensured to have a proper optical back focal length, and can be used for additionally arranging a beam splitter; the design of high resolution reduces the air space and simplifies the structure; the first lens group and the second lens group of the optical adapter are matched, so that the incident angle (CRA) of the chief ray is matched with the image sensor, and better luminance response can be obtained in different fields of view; due to the addition of the light splitter, light can be split, frequency selection can be carried out on the spectrum, and a special spectrum is extracted and used for special spectrum polarization imaging; under the condition of blurring in the operation, the polarized light imaging can realize the functions of blood permeation, bone residue permeation, fog permeation and/or turbid liquid permeation, and the like, and provides a clearer image, so that the operation visual field in the operation can be kept continuously clear, and the safety and the effectiveness of the operation are greatly improved.

In the above embodiments of the present invention, the white light image sensor or the polarized light image sensor may be a prior art image sensor, such as a CCD image sensor or a CMOS image sensor, only with respect to the light band received by the image sensor. Meanwhile, the polarized light imaging can adopt an image sensor sensitive to the polarization state of light in the prior art or an image sensor more suitable for polarized light imaging.

The present invention has been described in terms of specific examples, which are provided to aid understanding of the invention and are not intended to be limiting. For a person skilled in the art to which the invention pertains, several simple deductions, modifications or substitutions may be made according to the idea of the invention. For example, in each embodiment of the present invention, the cemented doublet or cemented triplet may be replaced by separate corresponding negative and positive lenses, and the separate lenses may also be implemented by corresponding cemented lenses, the relative positions of the first and second lens groups may be properly adjusted, and the positions of the lenses in the lens groups may also be properly adjusted, as long as the requirements of the overall parameters of the optical adapter can be met. The shape of the beam splitter is not limited to the embodiment, and may be any shape as long as the beam splitting characteristics satisfy the requirements.

Claims

1. A polarized light endoscope apparatus camera optical system, comprising: the optical adapter and the optical splitter are arranged in sequence from the object side to the image side in the axial direction; the optical splitter has the optical characteristic of selecting the wavelength of light waves into two wave bands of 380 nm-lambda and lambda-700 nm, reflects the light waves with the wavelength of 380 nm-lambda and transmits the light waves with the wavelength of lambda-700 nm at the same time, or transmits the light waves with the wavelength of 380 nm-lambda and reflects the light waves with the wavelength of lambda-700 nm at the same time; the lambda is any value within the range of 600 nm-670 nm; the light wave with the wave band of 380 nm-lambda separated by the light splitter is used for common white light imaging, and the light wave with the wave band of lambda-700 nm separated by the light splitter is used for polarized light imaging.

2. The optical system of a camera for a polarized endoscope apparatus according to claim 1, wherein said optical adapter has a focal length of 27 to 35mm and a reverse-to-distance ratio of 1 to 1.5.

3. The polarized-light endoscope apparatus camera optical system according to claim 2, characterized in that said optical adapter comprises a first lens group (10) and a second lens group (20) arranged axially in order from an object side to an image side; the focal length of the first lens group is 15-25 nm; the focal length of the second lens group is 100-150 nm.

4. The polarized light endoscope apparatus camera optical system of claim 2, wherein said λ has a value of 635 nm.

5. The polarized-light endoscope apparatus camera optical system according to claim 3, characterized in that said first lens group (10) includes a first lens group doublet cemented lens (101) and a first lens group positive lens (102) arranged in order from an object side to an image side in an axial direction; the second lens group (20) comprises a second lens group first negative lens (201), a second lens group second negative lens (202), a second lens group positive lens (203) and a second lens group double cemented lens (204) which are sequentially and axially arranged in a sealing manner from the object side to the image side.

6. The polarized light endoscope apparatus camera optical system according to any one of claims 1 to 5, wherein said beam splitter comprises two right-angle prisms bonded to each other, and a splitting plane thereof has an optical characteristic of selecting a wavelength of a light wave to be split into two wavelength bands of 380nm to λ and λ to 700 nm.

7. The polarized-light endoscope apparatus camera optical system according to claim 6, wherein a plurality of dielectric optical films are provided on the splitting surface of said beam splitter.

8. The polarized-light endoscopic-device camera optical system according to claim 7, wherein said multilayer dielectric optical film comprises a high-refractive-index material film layer and a low-refractive-index material film layer, which are laminated in this order.

9. A camera for a polarized light endoscopic device, comprising a white light image sensor; characterized by further comprising a polarized light image sensor and the polarized light endoscope apparatus camera optical system according to any one of claims 1 to 8; the 380 nm-lambda wave band light wave is imaged on the white light image sensor, and the lambda-700 nm wave band light wave is imaged on the polarized light image sensor.

10. A polarized light endoscope apparatus, comprising the camera head for a polarized light endoscope apparatus according to claim 9.