CN114176485B

CN114176485B - Endoscope device camera polarized light optical system, camera and endoscope device

Info

Publication number: CN114176485B
Application number: CN202111546616.5A
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: 2023-08-04
Anticipated expiration: 2041-12-16
Also published as: CN114176485A

Abstract

The invention mainly discloses a polarized light optical system of a camera of an endoscope device, which comprises an optical adapter and a beam splitter, wherein the optical adapter and the beam splitter are sequentially arranged from an object side to an image side; the optical splitter has optical characteristics of dividing the wavelength of light waves into R, G, B three wave bands and selecting a wave band of special light lambda-700 nm, wherein lambda is any value in the range of 600-670 nm; transmitting light waves of one wave band and reflecting light waves of the other three wave bands at the same time; and imaging is carried out respectively, so that a common white light image and a polarized light image in the operation can be obtained simultaneously, and the common white light image and the polarized light image are mutually and mutually supplemented. Under the condition of blurred environment in the operation, polarized light imaging can provide clearer images, and the functions of blood permeation, bone penetration and the like are realized, 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.

Description

Endoscope device camera polarized light optical system, camera and endoscope device

Technical Field

The invention relates to the technical field of endoscopes, in particular to an endoscope device.

Background

The medical endoscope is a medical electronic optical instrument which can be inserted into the cavity of human body and the internal cavity of viscera to directly observe, diagnose and treat, and adopts an optical lens with very small size to optically image the object in the cavity to be observed through a tiny objective imaging system, then the optical imaging is sent to an image processing host, and finally the observed image after the image processing is output on a display screen for observation and diagnosis by doctors.

Referring to fig. 1, the current endoscope apparatus generally includes a light source, an endoscope, a camera, and a host. The optical system of the camera generally includes an optical adapter lens, which is divided into a fixed focal length adapter (i.e., an optical lens Jiao Shi adapter) and a variable focal length adapter (i.e., an optical zoom adapter), and a mechanical structure for supporting the adapter. After being connected with an endoscope ocular through an ocular connecting module, the image information of the endoscope is transmitted to an optical lens Jiao Shi adapter, and the image information is acquired by an imaging rear-end image sensor and is amplified and displayed on a display.

The scattering phenomenon of light is a phenomenon in which a part of light propagates away from the original direction when the light passes through an uneven medium, and the light away from the original direction is called scattered light. Scattered light can affect imaging sharpness, causing blurring of the target and even undetectable targets. In clinical operations (such as orthopedic operations, urinary surgery, gynecological operations, etc.) using an endoscope apparatus, physiological saline medium is filled in a surgical cavity, and these substances constitute a non-uniform medium, so that reflected light of such medium is scattered to affect imaging definition of the endoscope apparatus. Whether scattered light in a non-uniform medium can be effectively inhibited, and the improvement of the definition of the view field in operation is particularly important.

Disclosure of Invention

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

Accordingly, one embodiment of the present invention provides a polarized light endoscopic device camera optical system comprising: an optical adapter and a beam splitter disposed in order from an object side to an image side; the optical splitter has the optical characteristics of dividing the wavelength of light waves into R, G, B three wave bands and selecting the wave band of special light lambda-700 nm; transmitting light waves of one wave band and reflecting light waves of the other three wave bands at the same time; the R, G, B three-band light waves obtained by the light splitter are used for common imaging, and the lambda-700 nm-band light waves obtained by the light splitter are used for polarized light imaging; wherein lambda is any value in the range of 600nm to 670 nm.

In one embodiment, the optical system for polarized light of the camera of the endoscope device, the optical splitter comprises a first prism, a second prism, a third prism and a fourth prism, three light splitting surfaces are formed by gluing, and the three light splitting surfaces are combined to form the optical characteristic of selecting the light wave to be divided into R, G, B three wave bands and the wave band of special light lambda-700 nm.

In one embodiment, the three light splitting surfaces are respectively provided with a multi-layer medium optical film, so that the light wave is divided into R, G, B three wave bands and the optical characteristics of the special light lambda-700 nm wave bands are selected.

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

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

In one embodiment, the optical adapter comprises a first lens group and a second lens group, which are arranged in sequence from the object side to the image side; the focal length of the first lens group is 15-30 nm, and the first lens group has positive focal power; the focal length of the second lens group is 100-150 nm, and the second lens group has positive focal power.

Meanwhile, an embodiment of the present invention provides a camera for a polarized light endoscopic apparatus,

including a red light image sensor or a first white light image sensor, a green light image sensor or a second white light image sensor, a blue light image sensor or a third white light image sensor;

further comprising a polarized light image sensor and a polarized light endoscopic device camera optical system as defined in any one of claims 1 to 8;

the R, G, B three-band light waves are respectively imaged on the corresponding red light image sensor or first white light image sensor, green light image sensor or second white light image sensor, blue light image sensor or third white light image sensor, and the lambda-700 nm-band light waves are imaged on the polarized light image sensor.

Further, an embodiment of the present invention provides a polarized light endoscope apparatus, and a camera for a polarized light endoscope apparatus employing any of the above technical features.

According to the polarized light endoscope device of the embodiment, the optical adapter is used for adapting the optical splitter, the wavelength of light waves is divided into R, G, B three wave bands and special light lambda-700 nm, imaging is carried out respectively, and an intraoperative common white light image and a polarized light image can be obtained simultaneously and are mutually and mutually supplemented. Under the condition of blurred environment in the operation, polarized light imaging can provide clearer images, and the functions of blood permeation, bone penetration and the like are realized, 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.

Further, through effective selection of the focal length and the inverse far ratio of the optical adapter, the structure can be simplified, the air interval can be reduced, the volume miniaturization can be realized, and the effective resolution and the image quality of the optical system can be ensured; the narrower chief ray incidence angle is adopted to match with the image sensor, so that better brightness response can be obtained for different view fields; can also be effectively matched with a beam splitter, and provides a basis for further beam splitting and image acquisition.

Drawings

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

FIG. 2 is a schematic view of a polarized light endoscopic device according to an embodiment of the present invention;

FIG. 3 is a schematic view of a camera optical system of a polarized light endoscopic device according to an embodiment of the present invention;

FIG. 4 is a schematic view of an optical adapter in a camera optical system of a polarized light endoscopic device 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 view of a beam splitter in a camera optical system of a polarized light endoscopic device according to an embodiment of the present invention;

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

Detailed Description

The invention will be described in further detail below with reference to the drawings by means of specific embodiments. Wherein like elements in different embodiments are numbered alike in association. In the following embodiments, numerous specific details are set forth in order to provide a better understanding of the present application. However, one skilled in the art will readily recognize that some of the features may be omitted, or replaced by other elements, materials, or methods in different situations. In some instances, some operations associated with the present application have not been shown or described in the specification to avoid obscuring the core portions of the present application, and may not be necessary for a person skilled in the art to describe in detail the relevant operations based on the description herein and the general knowledge of one skilled in the art.

Furthermore, the described features, operations, or characteristics of the description may be combined in any suitable manner in various embodiments. Also, various steps or acts in the method descriptions may be interchanged or modified in a manner apparent to those of ordinary skill in the art. Thus, the various orders in the description and drawings are for clarity of description of only certain embodiments, and are not meant to be required orders unless otherwise indicated.

The numbering of the components itself, e.g. "first", "second", etc., is used herein merely to distinguish between the described objects and does not have any sequential or technical meaning. The terms "coupled" and "connected," as used herein, are intended to encompass both direct and indirect coupling (coupling), unless otherwise indicated.

In the present invention, the object side refers to the position of the lens closer to the object side, and the image side refers to the position of the lens closer to the image plane side. The lenses may be made of materials in the prior art, such as glass materials. Symbols "-" represent a range of values for a certain parameter, the range of values including two endpoint values; such as: lambda is 600nm to 670nm, and represents any value within the range of 600nm to 670nm, including 600nm and 670 nm.

In one embodiment of the present invention, please refer to fig. 2 and 3, fig. 2 is a schematic structural diagram of a polarized light endoscope apparatus, fig. 3 is a camera optical system therein, including an optical adapter and a beam splitter, the beam splitter divides an optical signal transmitted from the optical adapter into four wave bands, namely blue light B, green light G, red light R and a special light band, corresponding to 380-500 nm, 500-560 nm, 560 nm- λ and λ -700 nm spectra; transmitting light waves of one wave band and reflecting light waves of the other three wave bands at the same time; wherein lambda is any value in the range of 600nm to 670 nm. Blue light, green light and red light are correspondingly imaged on the blue light image sensor, the green light image sensor and the red light image sensor and are used for ordinary white light imaging; the special light band corresponds to imaging the polarized light image sensor for special imaging.

In one embodiment of the present invention, referring to fig. 4, the camera optical system includes an optical adapter Jiao Shi, which 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 positions, and the whole lens group can slightly move back and forth relative to the image sensor, so that focusing and depth-of-field adjusting effects are achieved.

In one embodiment of the present invention, the optical adapter of this embodiment has a focal length of 27-35 mm and an overall length of 30-40 mm (the overall length is the distance between the front protective sheet and the rear protective sheet), and is adapted to the optical splitter, and a contrast ratio structure is adopted, where the ratio of the working distance L (i.e. the distance between the rear protective sheet of the optical adapter and the image surface of the image sensor) and the focal length f is a contrast ratio, in this embodiment, the contrast ratio is 1-1.5, and by matching the first lens group 10 with the second lens group 20, the incident angle (CRA) of the chief ray is smaller than 15 ° and is well matched with the image sensor.

In one embodiment of the present invention, the first lens group 10 has a focal length of 15-30 mm and positive optical power, and includes a first lens group first positive lens 101, a first lens group first negative lens 102, a first lens group second positive lens 103 and a first lens group second negative lens 104, which are axially arranged in order from the object side. The first negative lens 102 of the first lens group, the second positive lens 103 of the first lens group and the second negative lens 104 of the first lens group are glued from the object side to the image side to form a three-glue lens, so that chromatic aberration can be eliminated, air intervals are reduced, and the structure is simplified.

In one embodiment of the present invention, the second lens group 20 has a focal length of 100-150 mm and a positive optical power. Comprises a second lens group first double cemented lens 201 and a second lens group second double cemented lens 202, which are axially arranged in order from the object side. Wherein the second lens group first double cemented lens 201 is formed by a negative lens and a positive lens cemented in the direction from the object side to the image side; the second lens group second double-cemented lens 202 is formed by a negative lens and a positive lens cemented in the direction from the object side to the image side; 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 indicator of the imaging quality of an optical system. Referring to fig. 5, in the above embodiment, when the resolution of the optical adapter satisfies 220lp/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, please refer to fig. 6, the beam splitter of the present invention includes a first prism 1, a second prism 2, a third prism 3 and a fourth prism 4, wherein a first beam splitting surface is disposed at a bonding position of the first prism 1 and the second prism 2, a second beam splitting surface is disposed at a bonding position of the second prism 2 and the third prism 3, and a third beam splitting surface is disposed at a bonding position of the third prism 3 and the fourth prism 4. The optical splitter splits the optical signal transmitted from the optical adapter into four bands, namely blue, green, red and special optical bands, corresponding to the light wave bands 380-500 nm, 500-560 nm, 560-635 nm and 635-700 nm, i.e. λ is 635nm in this example. Wherein, three wave bands of light waves are reflected on each light splitting surface to form a first reflected light beam, a second reflected light beam and a third reflected light beam, and one wave band of light waves is transmitted to form a transmitted light beam. The first reflected beam is imaged onto the first image sensor 11, the second reflected beam is imaged onto the second image sensor 12, the third reflected beam is imaged onto the third image sensor 13, and the transmitted beam is imaged onto the fourth image sensor 14. The first image sensor, the second image sensor, the third image sensor and the fourth image sensor are respectively used for the relative positions of the image sensors according to the wave bands of the received imaging light beams.

In one embodiment, the first prism 1 is a combination of a square prism and a triangular prism, the second prism 2 is a trapezoidal prism, the third prism 3 is an asymmetrically cut half-pentagonal prism, and the fourth prism 4 is a trapezoidal prism. The choice of prism shape is not exclusive as long as the optical performance requirements of the present invention can be achieved.

In one embodiment, each of the light splitting surfaces is coated with a multilayer dielectric optical film, and the multilayer dielectric optical film directly adopts a discrete dichroism filter film to select the frequency of the light wave, namely, to select the wavelength of the light wave, and the light wave is divided into four wave bands, namely, 380-500 nm, 500-560 nm, 560-635 nm and 635-700 nm, namely, B light, G light, R light and special light. The B light, the G light and the R light are used for common white light imaging, and the special light is used for polarized light imaging; respectively imaging the first image sensor, the second image sensor, the third image sensor and the fourth image sensor.

In each embodiment, the value of lambda is 635nm, on one hand, the light wave range of RGB is well covered, and the reduction degree and the imaging quality of RGB imaging are ensured; on the other hand, the special light with enough wavelength range can be collected, and the quality of polarized light imaging and clinical reference value can be ensured.

In one embodiment, the three light splitting surfaces of the light splitter are combined to form a light wave frequency selecting device, the light wave is divided into four wave bands, namely, the wave bands of 380-500 nm, 500-580 nm, 580-670 nm and 670-700 nm are corresponding to the light wave bands of B light, G light, R light and special light, namely, lambda is 670nm in the embodiment; the B light, the G light and the R light are used for common white light imaging, and the special light is used for polarized light imaging; respectively imaging the first image sensor, the second image sensor, the third image sensor and the fourth image sensor.

In one embodiment, the three light splitting surfaces of the light splitter are combined to form a light wave frequency selecting device, the light wave is divided into four wave bands, namely, the wave bands of 380-480 nm, 480-550 nm, 550-600 nm and 600-700 nm are corresponding to the light wave bands of B light, G light, R light and special light, namely, lambda is 600nm in the embodiment; the B light, the G light and the R light are used for common white light imaging, and the special light is used for polarized light imaging; respectively imaging the first image sensor, the second image sensor, the third image sensor and the fourth image sensor.

In one embodiment, one, two or three of the above red light image sensor, blue light image sensor and green light image sensor may be replaced by a common white light image sensor, so that common white light imaging with three wavelength bands of RGB may be realized. The image sensors of the following tables are selected from the group:

in one embodiment of the present invention, as shown in fig. 7, each of the light splitting surfaces is plated with a plurality of layers of materials with different refractive indexes, typically a high refractive index material layer and a low refractive index material layer, which are sequentially stacked; the high refractive index material film layer and the low refractive index material film layer can be arranged on the inclined plane of any prism in the light splitting surface, or the high refractive index material film layer can be arranged on the inclined plane of one prism, and the low refractive index material film layer is arranged on the inclined plane of the other prism. The incident angle of the light is 10-50 degrees, and the light with different wavelengths is transmitted and reflected by the film layer. Referring to the following table, different combinations of different light splitting surfaces and different refractive index material layers are configured to generate different light splitting modes, as shown in the following table.

Light splitting mode table

Spectral mode	First reflected light beam	Second reflected light beam	Third reflected light beam	Transmission ofLight beam
					1	Special light	G	B	R
2	B	Special light	G	R
					3	B	G	Special light	R
4	B	G	R	Special light

In the embodiments of the invention, the ratio of the working distance L (namely the distance between the rear protective sheet and the image surface of the image sensor) to the focal length f is the inverse far ratio, and the inverse far ratio is 1-1.5 through the design of the large inverse far ratio of the optical adapter, so that the optical adapter can be ensured to have proper optical rear intercept, and the optical splitter is beneficial to being additionally arranged; the high-resolution design reduces the air interval and simplifies the structure; the first lens group and the second lens group of the optical adapter are matched, so that the incidence angle (CRA) of the chief ray is matched with the image sensor, and better brightness response can be obtained for different view fields; due to the arrangement of the beam splitter, the light can be split and the frequency of the light can be selected, and the light spectrum with a special wave band can be extracted for polarized light imaging; under the condition of blurring in operation, polarized light imaging can provide clearer images, and the functions of blood permeation, bone penetration slag and the like are realized, so that the operation visual field in operation can be kept continuously clear, and the safety and the effectiveness of operation are greatly improved.

In the above embodiments of the present invention, the first white light image sensor, the second white light image sensor, and the third white light image sensor, the red light image sensor, the green light image sensor, the blue light image sensor, or the polarized light image sensor may be related art image sensors, 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 may employ an image sensor sensitive to the polarization state of light in the related art, or an image sensor more suitable for polarized light imaging.

The foregoing description of the invention has been presented for purposes of illustration and description, and is not intended to be limiting. Several simple deductions, modifications or substitutions may also be made by a person skilled in the art to which the invention pertains, based on the idea of the invention. For example, in the embodiments of the present invention, the two-cemented lens, the three-cemented lens, or the like may be replaced by separate corresponding negative lenses and positive lenses, which are sequentially arranged, and the separate lenses may be replaced by corresponding cemented lenses, so that the relative positions of the first lens group and the second lens group may be appropriately adjusted, and the arrangement positions of the lenses in each lens group may be appropriately adjusted, so long as the overall parameter requirements of the optical adapter can be ensured. The shape of the beam splitter is not limited to the embodiment, and may be any shape as long as the beam splitter can satisfy the requirements.

Claims

1. An endoscope apparatus camera polarized light optical system, comprising: an optical adapter and a beam splitter disposed in order from an object side to an image side; the optical splitter has optical characteristics of dividing the wavelength of light waves into R, G, B three wave bands and selecting the wave band lambda-700 nm of polarized light; transmitting light waves of one wave band and reflecting light waves of the other three wave bands at the same time; the R, G, B wave band light waves obtained by the light splitter are used for common imaging, and the lambda-700 nm wave band light waves obtained by the light splitter are used for polarized light imaging; wherein lambda is any value in the range of 600nm to 670nm; the light splitter comprises a first prism, a second prism, a third prism and a fourth prism, three light splitting surfaces are formed by gluing, and the three light splitting surfaces are combined to form the light splitter with the optical characteristics of selecting light waves into R, G, B three wave bands and polarized light lambda-700 nm wave bands.

2. The polarized light optical system for camera head of endoscope apparatus according to claim 1, wherein each of the three light splitting surfaces is provided with a multilayer dielectric optical film.

3. The polarized light optical system for camera head of endoscope apparatus according to claim 1, wherein the three light splitting surfaces are combined to form light wave transmission for light wave divided into one of R, G, B three wave bands and polarized light lambda-700 nm wave bands, and the other three wave band light wave reflections; the lambda had a value of 635nm.

4. The polarized light optical system for a camera of an endoscopic device as claimed in claim 2, wherein the multilayer dielectric optical film comprises a high refractive index material film layer and a low refractive index material film layer, which are sequentially laminated.

5. The polarized light optical system for camera head of endoscopic apparatus according to any one of claims 1 to 4, wherein said optical adapter has a focal length of 27 to 35mm and a back-to-back ratio of 1 to 1.5.

6. The endoscope apparatus camera polarized light optical system according to claim 5, wherein the optical adapter comprises a first lens group (10) and a second lens group (20) disposed in order from an object side to an image side; the focal length of the first lens group is 15-30 nm, and the first lens group has positive focal power; the focal length of the second lens group is 100-150 nm, and the second lens group has positive focal power.

7. The endoscope apparatus camera polarized light optical system according to claim 6, wherein the first lens group (10) includes a first lens group first positive lens (101), a first lens group second negative lens (102), a first lens group third positive lens (103) and a first lens group fourth negative lens (104) disposed in order from an object side image side axis; the second lens group (20) comprises a second lens group first double-cemented lens (201) and a second lens group second double-cemented lens (202) which are arranged in sequence from the object side to the image side.

8. A camera for a polarized light endoscopic device, comprising a red light image sensor, a green light image sensor, and a blue light image sensor; further comprising a polarized light image sensor and a polarized light endoscopic device camera optical system as defined in any one of claims 1 to 7; the R, G, B three wave band light waves are respectively imaged on the corresponding red light image sensor, green light image sensor and blue light image sensor, and the lambda-700 nm wave band light waves are imaged on the polarized light image sensor.

9. A polarized light endoscopic device comprising the camera head for a polarized light endoscopic device according to claim 8.