A 40X Wide-Bandwidth Long Working Distance Microscope Objective

Abstract

The present invention relates to the field of micro-objectives, and particularly to a 40x wide-band long working distance micro-objective. The 40x wide-band long working distance micro-objective is composed of a cemented lens group G1, a cemented lens group G2, a cemented lens group G3, a lens group G4, a lens group G5, and a cemented lens group G6 arranged in sequence from the image side to the object side along the optical axis; wherein, the cemented lens group G1 is located on one side of the cemented lens group G2, the cemented lens group G3 is located on the side of the cemented lens group G2 away from the cemented lens group G1, and the lens group G4 is located on the side of the cemented lens group G3 away from the cemented lens group G2. The 40x wide-band long working distance micro-objective provided by the present invention covers the white light band of 436-700nm and the infrared band of 1400-1600nm. When working in both bands simultaneously, there is no need for repeated focusing, avoiding the problems of time delay and positioning error caused by conversion, reducing the dependence on the professional skills of operators, and reducing the potential damage to samples such as embryos.

Description

Technical Field

[0001] The present invention relates to the field of micro-objectives, and in particular, to a 40x wide-band long working distance microscope objective. Background Art

[0002] Wide-band microscope objectives have shown extensive application values in many fields such as biomedicine and materials science. Especially in the semiconductor industry, wide-band microscope objectives play a crucial role in detecting film stress, critical dimensions, and wafer surface defects. In the field of assisted reproductive technology, precise micro-operations are often required in core technical processes such as embryo hatching and embryo cryopreservation. These operations not only require extremely high precision but also must adopt technical means such as laser cell wall breaking, punching, and cutting without damaging cells. The current micro-operation process is as follows: First, micro-imaging is completed under visible light illumination through a conventional microscope objective; then, it is switched to an infrared laser microscope objective for target calibration and micro-operation. However, there is a problem of conversion time delay in this process. At the same time, due to the possible repeat positioning error of the conversion mechanism, micro-operation personnel must have a high level of professional skills to ensure minimizing potential damage to embryos to the greatest extent.

[0003] The cover glass materials in the design of traditional microscope objectives usually default to H-K51 or H-K9. For application scenarios in specific professional fields such as assisted reproduction, embryo hatching, embryo freezing, and live cell culture, the cover glass materials usually use a combination of borosilicate glass (PYREX) and optical grade polycarbonate (PC). These two materials have refractive indices and Abbe dispersion coefficients significantly different from those of H-K51 or H-K9. Traditional microscope objectives cannot eliminate the spherical aberration and chromatic dispersion generated when borosilicate glass (PYREX) and optical grade polycarbonate (PC with an Abbe number of 30, similar to flint glass) are used in combination. The imaging quality will significantly decline in this application scenario, and the deviation of the infrared laser focus position is large.

[0004] Therefore, it is necessary to provide a new 40x wide-band long working distance microscope objective to solve the above technical problems. Summary of the Invention

[0005] To overcome the defects of the prior art, a 40x wide-band long working distance microscope objective is provided to solve the above problems.

[0006] The 40x wide-band long working distance microscopic objective lens provided by the present invention comprises: a cemented lens group G1, a cemented lens group G2, a cemented lens group G3, a lens group G4, a lens group G5, and a cemented lens group G6 arranged in sequence from the image side to the object side along the optical axis; wherein, the cemented lens group G1 is located on one side of the cemented lens group G2, the cemented lens group G3 is located on the side of the cemented lens group G2 away from the cemented lens group G1, the lens group G4 is located on the side of the cemented lens group G3 away from the cemented lens group G2, the lens group G5 is located on the side of the lens group G4 away from the cemented lens group G3, and the cemented lens group G6 is located on the side of the lens group G5 away from the lens group G4; the cemented lens group G1 is composed of a double concave negative lens L1 and a double convex positive lens L2 cemented together and arranged in sequence from the image side to the object side along the optical axis, the cemented lens group G2 is composed of a meniscus negative lens L3 and a double convex positive lens L4 cemented together and arranged in sequence from the image side to the object side along the optical axis, and the concave surface of the meniscus negative lens L3 faces the object side, the cemented lens group G3 is composed of a meniscus negative lens L5 and a double convex positive lens L6 cemented together and arranged in sequence from the image side to the object side along the optical axis, and the concave surface of the meniscus negative lens L5 faces the object side; the lens group G4 includes a meniscus positive lens L7, and the meniscus positive lens L7 is located on the side of the double convex positive lens L6 away from the meniscus negative lens L5, and the concave surface of the meniscus positive lens L7 faces the object side; the lens group G5 includes a meniscus positive lens L8, and the meniscus positive lens L8 is located on the side of the meniscus positive lens L7 away from the double convex positive lens L6, and the convex surface of the meniscus positive lens L8 faces the image side; the cemented lens group G6 is composed of a plano lens L9 and a plano lens L10 cemented together and arranged in sequence from the object side to the image side along the optical axis.

[0007] Preferably, the double concave negative lens L1, the double convex positive lens L2, the meniscus positive lens L7, and the meniscus positive lens L8 are all made of lanthanide optical glass.

[0008] Preferably, the double convex positive lens L4 and the double convex positive lens L6 are both made of phosphate crown optical glass.

[0009] Preferably, the meniscus negative lens L3 is made of heavy flint optical glass.

[0010] Preferably, the meniscus negative lens L5 is made of light flint optical glass.

[0011] Preferably, the plano lens L9 is made of optical glass.

[0012] Preferably, the plano lens L10 is made of optical plastic.

[0013] Preferably, the focal length of the cemented lens group G1 is fG1, the focal length of the cemented lens group G2 is fG2, and the focal length of the cemented lens group G3 is fG3. They satisfy the conditional formula: -85 mm < fG1 < -75 mm, 30 mm < fG2 < 40 mm, 15 mm < fG3 < 25 mm.

[0014] Preferably, the focal length of the meniscus positive lens L8 is fL8, which satisfies the conditional formula: 7 mm < fL8 < 11 mm.

[0015] Compared with the related art, the 40x wide-band long working distance microscope objective provided by the present invention has the following beneficial effects:

[0016] The microscope objective of the present invention works in a wide band, covering the white light band of 436 - 700 nm and the infrared band of 1400 - 1600 nm. When working in both bands simultaneously, there is no need for repeated focusing, avoiding the problems of time delay and positioning error caused by conversion, reducing the dependence on the professional skills of operators, and reducing potential damage to samples such as embryos.

[0017] By selecting specific optical glass and plastic materials in the present invention, such as the plano-convex lens L9 using high borosilicate PYREX7740 optical glass with high thermal stability and high corrosion resistance, and the plano-convex lens L10 using polycarbonate (PC) optical plastic with high transmittance, relatively high mechanical strength, and low Abbe number, and through reasonable lens combination design, the spherical aberration and chromatic dispersion generated by this composite cover glass material are effectively eliminated, improving the imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of a preferred embodiment of the 40x wide-band long working distance microscope objective provided by the present invention;

[0019] Figure 2 It is a planar structural diagram of the 40x wide-band microscope objective;

[0020] Figure 3 It is an axial chromatic aberration diagram of the 40x wide-band microscope objective;

[0021] Figure 4 It is a field curvature and astigmatism diagram of the 40x wide-band microscope objective;

[0022] Figure 5 It is a distortion diagram of the 40x wide-band microscope objective;

[0023] Figure 6 It is a white light transfer function diagram of the 40x wide-band microscope objective;

[0024] Figure 7 It is a PSF diagram of the 40x wide-band microscope objective for the near-infrared 1480 nm spectral line;

[0025] Figure 8 It is the transmittance curve of a 40x wide-band microscopic objective lens in the wavelength range of 436 - 1550 nm. Specific embodiments

[0026] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] The following describes in detail the specific implementation of the present invention with reference to specific embodiments.

[0028] Embodiment 1

[0029] A 40x wide-band long working distance microscopic objective lens provided by an embodiment of the present invention includes a cemented lens group G1, a cemented lens group G2, a cemented lens group G3, a lens group G4, a lens group G5, and a cemented lens group G6 arranged in sequence along the optical axis from the image side to the object side. Among them, the cemented lens group G1 is located on one side of the cemented lens group G2, the cemented lens group G3 is located on the side of the cemented lens group G2 away from the cemented lens group G1, the lens group G4 is located on the side of the cemented lens group G3 away from the cemented lens group G2, the lens group G5 is located on the side of the lens group G4 away from the cemented lens group G3, and the cemented lens group G6 is located on the side of the lens group G5 away from the lens group G4. The cemented lens group G1 is composed of a biconcave negative lens L1 and a biconvex positive lens L2 cemented together and arranged in sequence along the optical axis from the image side to the object side. The cemented lens group G2 is composed of a meniscus negative lens L3 and a biconvex positive lens L4 cemented together and arranged in sequence along the optical axis from the image side to the object side, and the concave surface of the meniscus negative lens L3 faces the object side. The cemented lens group G3 is composed of a meniscus negative lens L5 and a biconvex positive lens L6 cemented together and arranged in sequence along the optical axis from the image side to the object side, and the concave surface of the meniscus negative lens L5 faces the object side. The lens group G4 includes a meniscus positive lens L7, and the meniscus positive lens L7 is located on the side of the biconvex positive lens L6 away from the meniscus negative lens L5, and the concave surface of the meniscus positive lens L7 faces the object side. The lens group G5 includes a meniscus positive lens L8, and the meniscus positive lens L8 is located on the side of the meniscus positive lens L7 away from the biconvex positive lens L6, and the convex surface of the meniscus positive lens L8 faces the image side. The cemented lens group G6 is composed of a plano-convex lens L9 and a plano-convex lens L10 cemented together and arranged in sequence along the optical axis from the object side to the image side.

[0030] Furthermore, the biconcave negative lens L1, the biconvex positive lens L2, the meniscus positive lens L7, and the meniscus positive lens L8 are all made of lanthanide optical glass with high refractive index and high transmittance in the infrared band to enhance the spherical aberration correction ability.

[0031] Further, the biconvex positive lens L4 and the biconvex positive lens L6 both adopt phosphate crown optical glass with high refractive index, high Abbe number, and high transmittance in the infrared band to enhance the achromatic and apochromatic aberration correction capabilities and improve the imaging quality.

[0032] Further, the meniscus negative lens L3 adopts heavy flint optical glass with high refractive index and low Abbe number to further improve the transmittance in the visible to near-infrared band.

[0033] Further, the meniscus negative lens L5 adopts light flint optical glass with medium refractive index and high Abbe number to further improve the achromatic aberration correction ability.

[0034] Further, the planar lens L9 adopts high-borosilicate PYREX7740 optical glass with high thermal stability and high corrosion resistance, and the thickness is 0.7 mm.

[0035] Further, the planar lens L10 adopts polycarbonate (PC) optical plastic with high transmittance, relatively high mechanical strength, and low Abbe number, and the thickness is 0.5 mm.

[0036] Further, the focal length fG1 of the cemented lens group G1 satisfies: -85 mm < fG1 < -75 mm, the focal length fG2 of the cemented lens group G2 satisfies: 30 mm < fG2 < 40 mm, the focal length fG3 of the cemented lens group G3 satisfies: 15 mm < fG3 < 25 mm, the focal length fL8 of the meniscus positive lens L8 satisfies: 7 mm < fL8 < 11 mm, the combined focal length fT2 of the lens groups G2, G3, and G4 and the focal length of the entire 40x wide-band microscopic objective lens satisfy: 4 < fT2 / fobj < 8, and the focal length fT3 of the lens group T3 and the focal length of the entire 40x wide-band microscopic objective lens satisfy: 1.4 < fT3 / fobj < 2.2.

[0037] A 40x wide-band microscopic objective lens uses wavelengths of 436 - 700 nm and 1400 - 1600 nm, and the specific parameters are as follows: magnification: β = 40; focal length: fobj = 5 mm; object field of view: not less than diameter φ0.55 mm; numerical aperture: NA = 0.5; working distance: W.D = 3.02 mm.

[0038] Example 2

[0039] A 40X wide-band microscopic objective lens, which consists of a double-concave negative lens L1, a double-convex positive lens L2, a diaphragm, a meniscus negative lens L3, a double-convex positive lens L4, a meniscus negative lens L5, a double-convex positive lens L6, a meniscus positive lens L7, a meniscus positive lens L8, a flat glass L9, and a flat plastic L10 arranged in sequence along the optical axis from the image side to the object side; the double-concave negative lens L1 and the double-convex positive lens L2 are cemented together to form a cemented lens group G1, the meniscus negative lens L3 and the double-convex positive lens L4 are cemented together to form a cemented lens group G2, and the meniscus negative lens L5 and the double-convex positive lens L6 are cemented together to form a cemented lens group G3.

[0040] Furthermore, the double-concave negative lens L1, the double-convex positive lens L2, the meniscus positive lens L7, and the meniscus positive lens L8 are all made of lanthanide optical glass with high refractive index and high transmittance in the infrared band to enhance the spherical aberration correction ability.

[0041] Furthermore, the double-convex positive lenses L4 and L6 are both made of phosphate crown optical glass with high refractive index, high Abbe number, and high transmittance in the infrared band to enhance the chromatic aberration and apochromatism correction abilities and improve the imaging quality.

[0042] Furthermore, the meniscus negative lens L3 is made of heavy flint optical glass with high refractive index and low Abbe number to further improve the transmittance in the visible to near-infrared band.

[0043] Furthermore, the flat lens L9 is made of high-borosilicate PYREX7740 optical glass with high thermal stability and high corrosion resistance, with a thickness of 0.7 mm, and is a constant-temperature glass hot stage for the biomedical field.

[0044] Furthermore, the flat lens L10 is made of polycarbonate (PC) optical plastic with high transmittance, relatively high mechanical strength, and low Abbe number, with a thickness of 0.5 mm, and is a culture dish for the biomedical field.

[0045] Furthermore, the focal length fL1 of the double-concave negative lens L1 satisfies: -6 mm < fL1 < -3 mm.

[0046] Furthermore, the focal length fL2 of the double-convex positive lens L2 satisfies: 6 < fL2 < 10 mm.

[0047] Furthermore, the focal length fL3 of the meniscus negative lens L3 satisfies: -20 mm < fL3 < -13 mm.

[0048] Furthermore, the focal length fL4 of the double-convex positive lens L4 satisfies: 9 mm < fL4 < 15 mm.

[0049] Furthermore, the focal length fL5 of the meniscus negative lens L5 satisfies: -15 mm < fL5 < -9 mm.

[0050] Further, the focal length fL6 of the biconvex positive lens L6 satisfies: 6 mm < fL6 < 10 mm.

[0051] Further, the focal length fL8 of the meniscus positive lens L8 satisfies: 7 mm < fL8 < 11 mm.

[0052] Further, the thickness DL9 of the flat glass L9 satisfies: 0.3 mm < DL9 < 0.7 mm.

[0053] Further, the thickness DL10 of the flat plastic L10 satisfies: 0.5 mm < DL10 < 1.0 mm.

[0054] A 40x wide-band microscopic objective lens uses wavelengths of 436 - 700 nm and 1400 - 1600 nm, and the specific parameters are as follows:

[0055] Magnification: β = 40; focal length: fobj = 5 mm; object field of view: φ0.55 mm; numerical aperture: NA = 0.5; working distance: W.D = 3.02 mm;

[0056] Further, the focal length fG1 of the cemented lens group G1 satisfies: -85 mm < fG1 < -75 mm.

[0057] Further, the focal length fG2 of the cemented lens group G2 satisfies: 30 mm < fG2 < 40 mm.

[0058] Further, the focal length fG3 of the cemented lens group G3 satisfies: 15 mm < fG3 < 25 mm.

[0059] Further, the combined focal length fT2 of the lens groups G2, G3, and G4 and the focal length of the entire 40x wide-band microscopic objective lens satisfy: 4 < fT2 / fobj < 8.

[0060] Further, the focal length fT3 of the lens group T3 and the focal length of the entire 40x wide-band microscopic objective lens satisfy: 1.4 < fT3 / fobj < 2.2.

[0061] The present invention has the characteristics of wide band, long working distance, and high infrared transmittance. The wavelengths used for white light are: 436 - 700 nm; the wavelengths used for infrared are: 1400 - 1600 nm; the focus shift of all spectral lines of white light is less than 1 / 2 of the focal depth of the infrared wavelength, and no repeated focusing is required when working in dual bands simultaneously.

[0062] The lens distribution and detailed parameters of this embodiment are as follows in the table:

[0063]

[0064] Among them, the radius refers to the radius of curvature of the surface, and the thickness refers to the axial distance from the current surface to the next surface. For example, the thickness of surface S1 is the distance from S1 to S2, which may be the axial thickness of the medium or the lens, or the axial air gap between them.

[0065] Figure 2 The MTF contrast for imaging in the 436 - 700 nm band is shown. The abscissa represents the spatial frequency, and the ordinate represents the normalized contrast. It can be seen from the figure that the MTF contrast is good at various spatial frequencies for most of the fields of view.

[0066] Figure 3 Axial chromatic aberration is shown. The minimum unit of the abscissa is 0.002 um, and the ordinate represents the aperture. The maximum focus shift on the axis shown in the figure is < 0.5 um.

[0067] Figure 4 Field curvature is shown. The abscissa represents the field curvature, with a minimum unit of 0.005 um, and the ordinate represents the field of view. The figure shows that the axial difference value between the edge field of view and the central field of view focus points is small, meeting the requirement of clear full field of view and achieving the requirements of a flat - field objective lens.

[0068] Figure 5 Distortion is shown. The abscissa represents the percentage of distortion, with a minimum unit of 0.2%, and the ordinate represents the field of view. The figure shows that the maximum distortion value of the full field of view is < 1%.

[0069] Figure 6 Wavefront error is shown. This figure is the wavefront diagram of the central field of view of the 632 nm spectral line, and its RMS < 0.1λ.

[0070] Figure 7 Huygens PSF is shown. The Strehl ratio of the central field of view of the 1480 nm spectral line in this figure is 0.94, and the aberration correction is good.

[0071] Figure 8 This is the transmittance simulation diagram of each spectral line of the 40 - fold wide - band microscopic objective lens within the 436 - 1600 nm band. It can be seen from the figure that the transmittance in the 436 - 700 nm band is > 90%, and the transmittance in the 1400 - 1600 nm band is > 70%.

[0072] Example 3

[0073] A 40x wide-band microscopic objective lens, with a double-concave negative lens L1, a double-convex positive lens L2, a diaphragm, a meniscus negative lens L3, a double-convex positive lens L4, a meniscus negative lens L5, a double-convex positive lens L6, a meniscus positive lens L7, a meniscus positive lens L8, a flat glass L9, and a flat plastic L10 arranged in sequence along the optical axis from the image side to the object side; the double-concave negative lens L1 and the double-convex positive lens L2 are cemented to form a cemented lens group G1, the meniscus negative lens L3 and the double-convex positive lens L4 are cemented to form a cemented lens group G2, and the meniscus negative lens L5 and the double-convex positive lens L6 are cemented to form a cemented lens group G3.

[0074] Furthermore, the double-concave negative lens L1, the double-convex positive lens L2, the meniscus positive lens L7, and the meniscus positive lens L8 are all made of lanthanum optical glass with high refractive index and high transmittance in the infrared band to enhance the spherical aberration correction ability.

[0075] Furthermore, the double-convex positive lenses L4 and L6 are both made of phosphate crown optical glass with high refractive index, high Abbe number, and high transmittance in the infrared band to enhance the chromatic aberration and apochromatic aberration correction abilities and improve the imaging quality.

[0076] Furthermore, the meniscus negative lens L3 is made of heavy flint optical glass with high refractive index and low Abbe number to further improve the transmittance in the visible to near-infrared band.

[0077] Furthermore, the flat lens L9 is made of high-borosilicate PYREX7740 optical glass with high thermal stability and high corrosion resistance, with a thickness of 0.7 mm, and is a constant-temperature glass hot stage for the biomedical field.

[0078] Furthermore, the flat lens L10 is made of polycarbonate (PC) optical plastic with high transmittance, relatively high mechanical strength, and low Abbe number, with a thickness of 0.5 mm, and is a culture dish for the biomedical field.

[0079] Furthermore, the focal length fL1 of the double-concave negative lens L1 satisfies: -6 mm < fL1 < -3 mm.

[0080] Furthermore, the focal length fL2 of the double-convex positive lens L2 satisfies: 5 < fL2 < 9 mm.

[0081] Furthermore, the focal length fL3 of the meniscus negative lens L3 satisfies: -15 mm < fL3 < -9 mm.

[0082] Furthermore, the focal length fL4 of the double-convex positive lens L4 satisfies: 8 mm < fL4 < 13 mm.

[0083] Furthermore, the focal length fL5 of the meniscus negative lens L5 satisfies: -18 mm < fL5 < -13 mm.

[0084] Further, the focal length fL6 of the biconvex positive lens L6 satisfies: 5 mm < fL6 < 9 mm.

[0085] Further, the focal length fL8 of the meniscus positive lens L8 satisfies: 5 mm < fL8 < 10 mm.

[0086] Further, the thickness DL9 of the flat glass L9 satisfies: 0.3 mm < DL9 < 0.7 mm.

[0087] Further, the thickness DL10 of the flat plastic L10 satisfies: 0.5 mm < DL10 < 1.0 mm.

[0088] A 40x wide-band microscopic objective lens uses wavelengths of 436 - 700 nm and 1400 - 1600 nm. The specific parameters are as follows:

[0089] Magnification: β = 40; Focal length: fobj = 5 mm; Object field of view: φ0.55 mm; Numerical aperture: NA = 0.5; Working distance: W.D = 3.02 mm.

[0090] Further, the focal length fG1 of the cemented lens group G1 satisfies: -40 mm < fG1 < -65 mm.

[0091] Further, the focal length fG2 of the cemented lens group G2 satisfies: 45 mm < fG2 < 65 mm.

[0092] Further, the focal length fG3 of the cemented lens group G3 satisfies: 9 mm < fG3 < 18 mm.

[0093] Further, the combined focal length fT2 of the lens groups G2, G3, and G4 and the focal length of the entire 40x wide-band microscopic objective lens satisfy: 1.2 < fT2 / fobj < 1.8.

[0094] Further, the focal length fT3 of the lens group T3 and the focal length of the entire 40x wide-band microscopic objective lens satisfy: 1 < fT3 / fobj < 2.

[0095] The present invention has the characteristics of a wide band, a long working distance, and a high infrared transmittance. The wavelengths used for white light are: 436 - 700 nm; the wavelengths used for infrared are: 1400 - 1600 nm; the focus shift of all spectral lines of white light is less than 1 / 2 of the focal depth of the infrared wavelength, and no repeated focusing is required when working in the two bands simultaneously.

[0096] The lens distribution and detailed parameters of this embodiment are as follows in the table:

[0097]

[0098] Among them, the radius refers to the radius of curvature of the surface, and the thickness refers to the axial distance from the current surface to the next surface. For example, the thickness of surface S1 is the distance from S1 to S2, which may be the axial thickness of the medium or the lens, or the axial air gap between them.

[0099] Figure 2 The displayed MTF contrast is for imaging in the 436 - 700 nm band. The abscissa represents the spatial frequency, and the ordinate represents the normalized contrast. It can be seen from the figure that the MTF contrast is good at each spatial frequency in most of the fields of view.

[0100] Figure 3 Axial chromatic aberration is shown. The minimum unit of the abscissa is 0.002 um, and the ordinate represents the aperture. The maximum focus shift on the axis shown in the figure is < 0.5 um.

[0101] Figure 4 Field curvature is shown. The abscissa represents the field curvature with a minimum unit of 0.005 um, and the ordinate represents the field of view. The figure shows that the axial difference value of the focal points between the edge field of view and the central field of view is small, meeting the requirement of clear full field of view and achieving the requirements of a flat-field objective lens.

[0102] Figure 5 Distortion is shown. The abscissa represents the percentage of distortion with a minimum unit of 0.2%, and the ordinate represents the field of view. The figure shows that the maximum distortion value of the full field of view is < 1%.

[0103] Figure 6 Wavefront error is shown. This figure is the wavefront diagram of the central field of view of the 632 nm spectral line, and its RMS < 0.1λ;

[0104] Figure 7 Huygens PSF is shown. The Strehl ratio of the central field of view of the 1480 nm spectral line in this figure is 0.94, and the aberration correction is good;

[0105] Figure 8 It is the transmittance simulation diagram of each spectral line of this 40x wide-band microscopic objective lens in the 436 - 1600 nm band. It can be seen from the figure that the transmittance in the 436 - 700 nm band is > 90%, and the transmittance in the 1400 - 1600 nm band is > 70%.

[0106] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A 40x wide-band long working distance microscopic objective lens, characterized in that, It is composed of a cemented lens group G1, a cemented lens group G2, a cemented lens group G3, a lens group G4, a lens group G5, and a cemented lens group G6 arranged in sequence along the optical axis from the image side to the object side; Among them, the cemented lens group G1 is located on one side of the cemented lens group G2, the cemented lens group G3 is located on the side of the cemented lens group G2 away from the cemented lens group G1, the lens group G4 is located on the side of the cemented lens group G3 away from the cemented lens group G2, the lens group G5 is located on the side of the lens group G4 away from the cemented lens group G3, and the cemented lens group G6 is located on the side of the lens group G5 away from the lens group G4; The cemented lens group G1 is composed of a biconcave negative lens L1 and a biconvex positive lens L2 cemented together and arranged in sequence along the optical axis from the image side to the object side. The cemented lens group G2 is composed of a meniscus negative lens L3 and a biconvex positive lens L4 cemented together and arranged in sequence along the optical axis from the image side to the object side, and the concave surface of the meniscus negative lens L3 faces the object side. The cemented lens group G3 is composed of a meniscus negative lens L5 and a biconvex positive lens L6 cemented together and arranged in sequence along the optical axis from the image side to the object side, and the concave surface of the meniscus negative lens L5 faces the object side; The lens group G4 is composed of a meniscus positive lens L7, and the meniscus positive lens L7 is located on the side of the biconvex positive lens L6 away from the meniscus negative lens L5, and the concave surface of the meniscus positive lens L7 faces the object side; The lens group G5 is composed of a meniscus positive lens L8, and the meniscus positive lens L8 is located on the side of the meniscus positive lens L7 away from the biconvex positive lens L6, and the convex surface of the meniscus positive lens L8 faces the image side; The cemented lens group G6 is composed of a plano lens L9 and a plano lens L10 cemented together and arranged in sequence along the optical axis from the image side to the object side; The focal length of the cemented lens group G1 is fG1, the focal length of the cemented lens group G2 is fG2, and the focal length of the cemented lens group G3 is fG3. They satisfy the conditional formula: -85mm < fG1 < -75mm, 30mm < fG2 < 40mm, 15mm < fG3 < 25mm.

2. The 40x wide-band long working distance microscope objective lens according to claim 1, characterized in that The biconcave negative lens L1, the biconvex positive lens L2, the meniscus positive lens L7, and the meniscus positive lens L8 are all made of lanthanide optical glass.

3. The 40x wide-band long working distance microscopic objective lens according to claim 1, characterized in that, The biconvex positive lenses L4 and L6 are both made of phosphate crown optical glass.

4. The 40x wide-band long working distance microscope objective lens according to claim 1, characterized in that, The meniscus negative lens L3 is made of heavy flint optical glass.

5. The 40x wide-band long working distance microscope objective lens according to claim 1, characterized in that, The meniscus negative lens L5 is made of light flint optical glass.

6. The 40x wide-band long working distance microscope objective according to claim 1, characterized in that, The plano lens L9 is made of optical glass.

7. The 40X wide-band long working distance microscope objective according to claim 1, characterized in that, The plano lens L10 is made of optical plastic.

8. The 40x wide-band long working distance microscopic objective lens according to claim 1, characterized in that, The focal length of the meniscus positive lens L8 is fL8, which satisfies the conditional formula: 7mm < fL8 < 11mm.

Images