CN111904373A - A relay mirror structure of 4K ultra-high-definition laparoscope - Google Patents

Abstract

The invention relates to a relay mirror structure of a 4K ultra-high-definition laparoscope. The triplet lens group includes a first lens, a second lens and a third lens. One surface of the first lens is an even-order aspherical structure, the other surface is concave, and the two surfaces of the second lens are Both are convex, one side surface of the third lens is concave, the other side surface is an even-order aspheric structure, the concave surface of the first lens and the convex surface of the second lens are opposite and glued into one, the said The other convex surface of the second lens is opposite to the concave surface of the third lens and is cemented into one. In order to realize that the numerical aperture reaches 0.12, the present invention achieves the balance of aberrations when compared with the FHD and increases by 50%, so that the 4K resolution can be satisfied.

Description

A relay mirror structure of 4K ultra-high-definition laparoscope

technical field

The invention relates to a relay mirror structure, in particular to a relay mirror structure of a 4K ultra-high-definition laparoscope, which belongs to the technical field of laparoscopy in medical equipment.

Background technique

The rigid tube laparoscope consists of three parts, the objective lens (Objective), the relay lens (Relay Lens) and the eyepiece (Ocular). Working principle: The lesion surface is illuminated by the light introduced by the optical fiber bundle, and the objective lens images the lesion surface to the rear focal plane of the objective lens. Three or five groups of relay systems with a magnification of -1 transmit the image of the rear focal plane of the objective lens to the eyepiece. Near the front focal plane, the exiting beam from the eyepiece's exit pupil is nearly parallel. The human eye can observe directly at the eyepiece exit pupil, or use an adapter to image the image onto the focal plane detector, which can be CCD or CMOS.

Among them, the relay mirror plays an important role in the rigid tube laparoscopy. Due to the large number, it is an important part of the cost of the endoscope. In order to reduce the cost, the relay mirror is generally designed into 3 groups of identical mirrors, each of which is completely symmetrical. The advantage of such a design is that the cost is low, and the price of the speculum can be effectively reduced to a reasonable range. The disadvantage is that the three sets of completely symmetrical relay mirrors will continuously accumulate the axial aberration, resulting in a large residual field curvature, which makes it difficult to balance the aberration of the entire speculum, especially in the design of 4K ultra-high-definition resolution laparoscopes. , such a disadvantage becomes unbearable. The resolution of 4K UHD laparoscopy is doubled compared to FHD, and the NA (numerical aperture: a key parameter that determines the limit resolution of the optical system, the larger the value, the higher the limit resolution that can be achieved) is expected to reach 0.12. Some structural forms are not enough to support the transmission of new and higher resolution rigid tube laparoscopic intermediate images.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a 4K ultra-high-definition laparoscope that can achieve a 4K ultra-high-definition laparoscope with a 50% increase in numerical aperture compared with FHD in order to achieve a numerical aperture of 0.12, which achieves a balance of aberrations and meets 4K resolution. of the mirror structure.

In order to achieve the above purpose, the technical solution of the present invention is: a 4K ultra-high-definition laparoscopic relay mirror structure, the innovative point of which is that it is composed of two completely symmetrical triplet lens groups, and the two groups of triplet lens groups are along the The light directions are cemented into one in sequence, and each group of three cemented lens groups includes a first lens, a second lens and a third lens,

One side surface of the first lens is an even-order aspheric structure, the other side surface is concave, both sides of the second lens are convex, one side surface of the third lens is concave, and the other side is concave. The side surface is an even-order aspheric structure,

The concave surface of the first lens is opposite to one side of the convex surface of the second lens and is cemented into one, and the other convex surface of the second lens is opposite to the concave surface of the third lens and is cemented into one.

In the above technical solution, the refractive index of the first lens is 1.67, the refractive index of the second lens is 1.62, and the refractive index of the third lens is 1.89.

In the above technical solution, the first lens, the second lens and the third lens are glued together by ultraviolet photosensitive adhesive.

In the above technical solution, the glass material of the second lens is F2 (CDGM), F4 (CDGM), F2 (HOYA), PBM2 (OHARA), F5 (SCHOTT), F1 (CDGM), F5 (HOYA), One of PBM5 (OHARA).

In the above technical solution, the even-order aspherical structure parameters of the first lens are:

-1.0E- ₆ >a2>=-1.0E-4

-2.0E- ₇ >a3>-2.0E-8

25>R>10

Among them, a ₂ is the fourth-order coefficient of the even-order aspheric surface, a ₃ is the sixth-order coefficient of the even-order aspheric surface, and R is the radius of curvature.

In the above technical solution, the aspherical structure parameters of the third lens are:

1.0E-3 > a ₂₁ >= 1.0E-4

-2.0E-5>a ₃₁ >-2.0E-4

30>R1>15

Among them, a ₂ is the fourth-order coefficient of the even-order aspheric surface, a ₃ is the sixth-order coefficient of the even-order aspheric surface, and R1 is the radius of curvature.

The positive effects of the present invention are: after adopting the relay mirror structure of the 4K ultra-high-definition laparoscope of the present invention, because the present invention is composed of two completely symmetrical triplet lens groups, and the two groups of triplet lens groups are along the light direction Cemented together in sequence, each group of three cemented lenses includes a first lens, a second lens and a third lens, one side surface of the first lens is an even-order aspherical structure, and the other side surface is a concave surface. Both sides of the second lens are convex, one side of the third lens is concave, the other side has an even-order aspheric structure, and the concave surface of the first lens is opposite to the convex side of the second lens and glued together as a whole, and the convex surface of the other side of the second lens is opposite to the concave surface of the third lens and is glued into one;

Since the one side surface (front surface) of the first lens and the other side surface (rear surface) of the third lens in the relay mirror structure of the present invention both adopt an even-order aspherical design, the NA (numerical aperture) reaches 0.12, which is 50% larger than that of FHD (Full Ultra High Definition), and achieves the balance of aberrations, and at the same time, the second lens has good transmittance in the visible light band and excellent colorability.

Description of drawings

1 is a schematic structural diagram of a relay mirror structure of a 4K ultra-high-definition laparoscope of the present invention;

Figure 2 is a comparison diagram of the transmittance curves of the three groups of rod lens groups as a whole with different materials of glass.

Detailed ways

The present invention is further described below with reference to the accompanying drawings and the given embodiments, but is not limited thereto.

As shown in Figure 1, a 4K ultra-high-definition laparoscope's relay mirror structure consists of two completely symmetrical triplet lens groups, and the two groups of triplet lens groups are sequentially glued together along the light direction. The lens group includes a first lens 1, a second lens 2 and a third lens 3,

One side surface of the first lens 1 is an even-order aspheric structure, the other side surface is concave, both sides of the second lens 2 are convex, and one side surface of the third lens 3 is concave , the other side surface is an even-order aspheric structure,

The concave surface of the first lens 1 is opposite to the convex surface of the second lens 2 and is cemented into one, and the other convex surface of the second lens 2 is opposite to the concave surface of the third lens 3 and is cemented into one.

Further, the first lens 1 , the second lens 2 and the third lens 3 of the present invention are glued together by ultraviolet photosensitive adhesive. The ultraviolet photosensitive adhesive is a high temperature resistant ultraviolet photosensitive adhesive, and the high temperature resistant temperature is 125°C to 135°C. The advantage of this design is that it can not only balance the chromatic aberration, but also ensure that the optical system can be sterilized by high-temperature steam without structural changes.

The even-order aspherical structure parameters of the first lens 1 according to the present invention are:

-1.0E- ₆ >a2>=-1.0E-4

-2.0E- ₇ >a3>-2.0E-8

25>R>10

Among them, a ₂ is the fourth-order coefficient of the even-order aspheric surface, a ₃ is the sixth-order coefficient of the even-order aspheric surface, and R is the radius of curvature. The refractive index of the first lens 1 is 1.67.

The glass material of the second lens 2 is F2(CDGM), F4(CDGM), F2(HOYA), PBM2(OHARA), F5(SCHOTT), F1(CDGM), F5(HOYA), PBM5(OHARA) a kind of. And the refractive index of the second lens 2 is 1.62.

The relay lens is the longest part of the laparoscope. Glass is an excellent medium for light transmission, and its absorption rate is usually negligible. The thickness of the glass will reach 270mm. The problem brought by the glass with higher transmittance is that the refractive index is low and the transmission capacity of optical information is insufficient. The high-refractive index glass often has insufficient transmittance in the blue light part, resulting in the color of the entire optical system. Insufficient restoring ability.

As shown in Figure 2, it is the transmittance curve of a glass N-BAF10 and F2 (CDGM) with a refractive index of 1.67 when the glass thickness is 270mm. In Figure 2, the abscissa is the wavelength (unit is um), and the ordinate is the transmittance. As can be seen from the figure, the glass selected by the present invention can satisfy high-resolution imaging, and at the same time have a consistent optical transmittance in the entire visible light band, and the transmittance remains above 90% transmittance in the visible light band, While other glass is difficult to complete.

Further, the aspherical structure parameters of the third lens 3 are:

1.0E-3 > a ₂₁ >= 1.0E-4

-2.0E-5>a ₃₁ >-2.0E-4

30>R1>15

Among them, a ₂ is the fourth-order coefficient of the even-order aspheric surface, a ₃ is the sixth-order coefficient of the even-order aspheric surface, and R1 is the radius of curvature. The refractive index of the third lens 3 is 1.89.

An example of a specific implementation is provided in Table 1 below:

Table 1

Since the one side surface (front surface) of the first lens and the other side surface (rear surface) of the third lens in the relay mirror structure of the present invention both adopt an even-order aspherical design, the NA (numerical aperture) reaches 0.12, which is 50% larger than that of FHD (Full Ultra High Definition), and achieves the balance of aberrations, and at the same time, the second lens has good transmittance in the visible light band and excellent colorability.

Taking the above ideal embodiments according to the present invention as inspiration, and through the above description, relevant personnel can make various changes and modifications without departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the contents in the specification, and the technical scope must be determined according to the scope of the claims.

Claims (6)

1. A relay mirror structure of a 4K ultra-high-definition laparoscope is characterized in that: it is composed of two groups of completely symmetrical three-joint mirror groups, and two groups of three-joint mirror groups are successively glued into one along the light direction, and each group of three joints is glued together. The lens groups all include a first lens (1), a second lens (2) and a third lens (3), One side surface of the first lens (1) is an even-order aspheric structure, the other side surface is concave, both sides of the second lens (2) are convex, and the third lens (3) One side surface is concave, and the other side surface is even-order aspheric structure, The concave surface of the first lens (1) and the convex surface on one side of the second lens (2) are opposite to each other and are cemented into one, and the convex surface on the other side of the second lens (2) is opposite to the concave surface of the third lens (3) and glued together. 2. The relay mirror structure of the 4K ultra-high-definition laparoscope according to claim 1, characterized in that: the refractive index of the first lens (1) is 1.67, and the refractive index of the second lens (2) is 1.62, and the refractive index of the third lens (3) is 1.89. 3. The relay mirror structure of 4K ultra-high-definition laparoscope according to claim 1, characterized in that: the first lens (1), the second lens (2) and the third lens (3) pass through ultraviolet photosensitive adhesive glued together. 4. The relay mirror structure of 4K ultra-high-definition laparoscope according to claim 1, characterized in that: the glass material of the second lens (2) is F2 (CDGM), F4 (CDGM), F2 (HOYA) , one of PBM2(OHARA), F5(SCHOTT), F1(CDGM), F5(HOYA), PBM5(OHARA). 5. The relay mirror structure of 4K ultra-high-definition laparoscope according to claim 1, characterized in that: the even-order aspherical structure parameters of the first lens (1) are: -1.0E- ₆ >a2>=-1.0E-4 -2.0E- ₇ >a3>-2.0E-8 25>R>10 Among them, a ₂ is the fourth-order coefficient of the even-order aspheric surface, a ₃ is the sixth-order coefficient of the even-order aspheric surface, and R is the radius of curvature. 6. The relay mirror structure of 4K ultra-high-definition laparoscope according to claim 1, characterized in that: the aspherical structure parameter of the third lens (3) is: 1.0E-3 > a ₂₁ >= 1.0E-4 -2.0E-5>a ₃₁ >-2.0E-4 30>R1>15 Among them, a ₂ is the fourth-order coefficient of the even-order aspheric surface, a ₃ is the sixth-order coefficient of the even-order aspheric surface, and R1 is the radius of curvature.

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