TW201819985A - Six-piece microscope lens system - Google Patents

Abstract

A six-piece microscope lens system includes, in order from the object side to the image side: a first lens element with a positive refractive power, a stop, a second lens element with a positive refractive power, a third lens element with a negative refractive power, a fourth lens element with a positive refractive power, a fifth lens element with a positive refractive power, and a sixth lens element with a negative refractive power. Such arrangements can provide a six-piece microscope lens system having small size, higher pixel and image magnification 4.5X.

Description

Six-piece microscope lens set

The present invention relates to a microscope lens set, and more particularly to a six-piece microscope lens set.

Optical microscopy has been widely used to view objects on coverslips, the optical system of which typically provides an image of the object on the focal plane. The optical component of the optical microscope mainly comprises two kinds of image taking lenses (ie, an eyepiece and an objective lens) and a condensing mirror for magnifying the image of the object and projecting the enlarged image to the retina or the image of the viewer. The backsheet of the machine, and the function of the concentrating mirror is to concentrate the incident light on the object. To provide the incident light, the optical microscope illumination system can include an incident light source or direct an external natural or artificial light to the concentrating mirror. In addition, the optical microscope can also selectively use optical elements that enhance image contrast. Furthermore, the optical microscope can also use a movable platform that can carry the object to the optical path and allow the object to move in and out of its focus plane, even to the right, left, or rotate along the optical axis.

However, at present, optical microscopes, regardless of their magnification, use an optical system that is too large in volume, especially for housing the microscope lens set, highlighting the disadvantages of high cost and poor space utilization. Therefore, how to develop a microscope lens set, which can reduce the volume to reduce the manufacturing cost, and has a large pixel, an image magnification of 4.5X, and a lens group capable of detecting biological fluids, which is the motivation for the development of the present invention. .

It is an object of the present invention to provide a six-piece microscope lens set, and more particularly to a lens set that reduces volume and reduces manufacturing costs while having a large pixel, an image magnification of 4.5X, and capable of detecting biological fluids.

In order to achieve the foregoing object, a six-piece microscope lens set according to the present invention comprises, in order from the object side to the image side, a first lens having a positive refractive power, and an image side surface near the optical axis. a convex surface, at least one surface of the object side surface and the image side surface is aspherical; an aperture; a second lens having a positive refractive power, the object side surface being convex at the near optical axis, and the object side surface and the image side surface At least one surface is aspherical; a third lens has a negative refractive power, and the image side surface has a convex surface at a near optical axis, and at least one surface of the object side surface and the image side surface is aspherical; a fourth lens has a positive The refractive power is a concave surface at the near-optical axis of the image side surface, and at least one surface of the object side surface and the image side surface is aspherical; a fifth lens has a positive refractive power, and the image side surface has a convex surface at a near optical axis. At least one surface of the object side surface and the image side surface is aspherical; a sixth lens having a negative refractive power, the object side surface being convex at the near optical axis, and at least one surface of the object side surface and the image side surface being aspherical .

Preferably, wherein the focal length of the first lens is f1, the focal length of the second lens is f2, and the following condition is satisfied: 1.0 < f1/f2 < 3.0. Thereby, the refractive power arrangement of the first lens and the second lens is suitable, which is advantageous for obtaining a wide angle of view (angle of view) and reducing excessive increase of system aberration.

Preferably, wherein the focal length of the second lens is f2, the focal length of the third lens is f3, and the following condition is satisfied: -2.0 < f2/f3 < -0.8. Thereby, the refractive power of the third lens can be effectively distributed while ensuring that the refractive power of the third lens is not excessively large, which is advantageous in reducing system sensitivity and reducing generation of aberrations.

Preferably, wherein the focal length of the third lens is f3, the focal length of the fourth lens is f4, and the following condition is satisfied: -0.3 < f3/f4 < -0.1. Thereby, the configuration of the refractive power can be effectively balanced to enhance the correction of the aberration of the wide-angle lens group.

Preferably, wherein the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, and the following condition is satisfied: 3.0 < f4/f5 < 7.0. Thereby, the chromatic aberration of the lens group of the image system can be balanced to improve the image quality.

Preferably, wherein the focal length of the fifth lens is f5, the focal length of the sixth lens is f6, and the following condition is satisfied: -1.0 < f5/f6 < -0.5. Thereby, the refractive power arrangement of the rear group lens system can be balanced, which is beneficial to the reduction of system sensitivity and the correction of high-order aberrations.

Preferably, wherein the focal length of the first lens is f1, the focal length of the third lens is f3, and the following condition is satisfied: -3.5 < f1/f3 < -2.0. Thereby, the refractive power of the first lens is effectively distributed, and the sensitivity of the six-piece microscope lens group is lowered.

Preferably, wherein the focal length of the second lens is f2, the focal length of the fourth lens is f4, and the following condition is satisfied: 0.1 < f2 / f4 < 0.4. Thereby, it is advantageous to enhance the large viewing angle and large aperture characteristics of the six-piece microscope lens group, and the sensitivity thereof can be reduced, which is advantageous for the manufacture of each lens and the improvement of the production yield.

Preferably, wherein the focal length of the third lens is f3, the focal length of the fifth lens is f5, and the following condition is satisfied: -1.1 < f3/f5 < -0.45. Thereby, it is advantageous to enhance the large viewing angle and large aperture characteristics of the six-piece microscope lens group, and the sensitivity thereof can be reduced, which is advantageous for the manufacture of each lens and the improvement of the production yield.

Preferably, wherein the focal length of the fourth lens is f4, the focal length of the sixth lens is f6, and the following condition is satisfied: -4.0 < f4/f6 < -2.2. Thereby, the sensitivity of the lens group of the camera system can be reduced, and the total length thereof can be effectively shortened.

Preferably, wherein the focal length of the first lens is f3, the combined focal length of the first lens and the second lens is f12, and the following condition is satisfied: -0.25 < f1/f23 < -0.05. Thereby, when f12/f3 satisfies the above conditions, the six-piece microscope lens group can be significantly improved in image resolution while obtaining a wide angle of view (angle of view).

Preferably, wherein the focal length of the second lens is f2, the combined focal length of the third lens and the fourth lens is f34, and the following condition is satisfied: -1.5 <f2/f34 < -0.8. Thereby, it is advantageous to enhance the large viewing angle and large aperture characteristics of the six-piece microscope lens group, and the sensitivity thereof can be reduced, which is advantageous for the manufacture of each lens and the improvement of the production yield.

Preferably, wherein the combined focal length of the second lens and the third lens is f23, the combined focal length of the fourth lens and the fifth lens is f45, and the following condition is satisfied: -16.0 <f23/f45 < -7.0. When f23/f45 satisfies the foregoing relationship, the six-piece microscope lens group can have a large picture angle, a high number of pictures, and a low lens height, and the resolution capability is remarkably improved. Otherwise, if the optical data value is exceeded. The range will result in problems with the performance, low resolution, and insufficient yield of the six-piece microscope lens set.

Preferably, wherein the combined focal length of the third lens and the fourth lens is f34, the combined focal length of the fifth lens and the sixth lens is f56, and the following condition is satisfied: -1.25 < f34/f56 < -0.60. When f34/f56 satisfies the foregoing relationship, the six-piece microscope lens group can have a large picture angle, a high number of pictures, and a low lens height, and the resolution capability is remarkably improved. Otherwise, if the optical data value is exceeded. The range will result in problems with the performance, low resolution, and insufficient yield of the six-piece microscope lens set.

Preferably, wherein the fourth lens and the fifth lens have a combined focal length of f45, the sixth lens has a focal length of f6, and satisfies the following condition: -1.3 < f45/f6 < -0.65. When f45/f6 satisfies the foregoing relationship, the six-piece microscope lens group can have a large picture angle, a high number of pictures, and a low lens height, and the resolution capability is remarkably improved. Conversely, if the optical data value is exceeded. The range will result in problems with the performance, low resolution, and insufficient yield of the six-piece microscope lens set.

Preferably, wherein the focal length of the first lens is f1, the combined focal length of the second lens, the third lens and the fourth lens is f234, and the following condition is satisfied: 0.05 < f1/f234 < 0.4. By proper configuration of the refractive power, it helps to reduce the occurrence of spherical aberration and astigmatism.

Preferably, wherein the second lens, the third lens and the fourth lens have a combined focal length of f234, the fifth lens and the sixth lens have a combined focal length of f56, and satisfy the following condition: 4.0 < f234/f56 < 15.0. By proper configuration of the refractive power, it helps to reduce the occurrence of spherical aberration and astigmatism.

Preferably, wherein the combined focal length of the second lens and the third lens is f23, the combined focal length of the fourth lens, the fifth lens and the sixth lens is f456, and the following condition is satisfied: -30 < f23/f456 < - 12. By proper configuration of the refractive power, it helps to reduce the occurrence of spherical aberration and astigmatism.

Preferably, wherein the focal length of the second lens is f2, the combined focal length of the third lens, the fourth lens and the fifth lens is f345, and the following condition is satisfied: 0.55 < f2 / f345 < 1.1. By proper configuration of the refractive power, it helps to reduce the occurrence of spherical aberration and astigmatism.

Preferably, wherein the focal length of the first lens is f1, the combined focal length of the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens is f2345, and the following condition is satisfied: 1.2 < f1/f23456 < 3.2. When f123/f456 satisfies the foregoing relationship, the six-piece microscope lens group can have a large picture angle, a high number of pictures, and a low lens height, and the resolution capability is remarkably improved. Conversely, if the optical data value is exceeded. The range will result in problems with the performance, low resolution, and insufficient yield of the six-piece microscope lens set.

The present invention has been described with reference to the preferred embodiments of the present invention in accordance with the accompanying drawings.

<First Embodiment>

1A and FIG. 1B, FIG. 1A is a schematic diagram of a six-piece microscope lens group according to a first embodiment of the present invention, and FIG. 1B is a six-piece microscope lens group of the first embodiment from left to right. Image curvature and distortion curve. As can be seen from FIG. 1A, the six-piece microscope lens assembly includes an aperture 100 and an optical group. The optical group sequentially includes a cover glass 191, a first lens 110, a positioning piece 192, and a second lens from the object side to the image side. 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, an infrared filter element 170, and an imaging surface 180, wherein the lens having a refractive power in the six-piece microscope lens group is Six pieces. The cover glass 191, the first lens 110, and the positioning piece 192 constitute a front group lens system. The second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, the sixth lens 160, and the infrared filter element 170 constitute a rear group lens system. The aperture 100 is disposed between the positioning piece 192 and the image side surface 122 of the second lens 120.

The cover glass 191 mainly protects and isolates the first lens 110 from being in contact with the object to be detected (for example, biological fluid), and the cover glass 191 is made of glass, which is disposed on the object side and the first surface. The object side surface 111 of the lens 110 does not affect the focal length of the six-piece microscope lens group.

The first lens 110 has a positive refractive power and is made of a plastic material. The object side surface 111 is concave at the near optical axis 190, and the image side surface 112 is convex at the near optical axis 190, and the object side surface 111 and the image side are Surface 112 is aspherical.

The positioning piece 192 and the cover glass 191 position the first lens 110, and the positioning piece 192 is made of a plastic material, and is disposed on the image side surface 112 of the first lens 110 and the object side surface 122 of the second lens 120. The focal length of the six-piece microscope lens set is not affected.

The second lens 120 has a positive refractive power and is made of a plastic material. The object side surface 121 is convex at the near optical axis 190, and the image side surface 122 is convex at the near optical axis 190, and the object side surface 121 and the image side are Surface 122 is aspherical.

The third lens 130 has a negative refractive power and is made of a plastic material. The object side surface 131 is concave at the near optical axis 190, and the image side surface 132 is concave at the near optical axis 190, and the object side surface 131 and the image side are The surfaces 132 are all aspherical.

The fourth lens 140 has a positive refractive power and is made of a plastic material. The object side surface 141 is convex at the near optical axis 190, and the image side surface 142 is concave at the near optical axis 190, and the object side surface 141 and the image side are Surfaces 142 are all aspherical.

The fifth lens 150 has a positive refractive power and is made of a plastic material. The object side surface 151 is convex at the near optical axis 190, and the image side surface 152 is convex at the near optical axis 190, and the object side surface 151 and the image side are Surface 152 is aspherical.

The sixth lens 160 has a negative refractive power and is made of a plastic material. The object side surface 161 is convex at the near optical axis 190, and the image side surface 162 is concave at the near optical axis 190, and the object side surface 161 and the image side are Surface 162 is aspherical.

The infrared filter element 170 is made of glass and disposed between the sixth lens 160 and the imaging surface 180 without affecting the focal length of the six-microscope lens group.

The aspherical curve equations of the above lenses are expressed as follows:

Where z is the position value with reference to the surface apex at a position of height h in the direction of the optical axis 190; c is the curvature of the lens surface near the optical axis 190, and is the reciprocal of the radius of curvature (R) (c = 1/R) R is the radius of curvature of the lens surface near the optical axis 190, h is the vertical distance of the lens surface from the optical axis 190, k is a conic constant, and A, B, C, D, E, G, ... are High order aspheric coefficient.

In the six-piece microscope lens group of the first embodiment, the focal length of the six-piece microscope lens group is f, the numerical aperture of the object side of the six-piece microscope lens group is NA, and the magnification of the six-piece microscope lens group is MA. The values are as follows: f = 2.999 (mm); NA = 0.3 (mm); and MA = 4.5.

In the six-piece microscope lens group of the first embodiment, the focal length of the first lens 110 is f1, the focal length of the second lens 120 is f2, and the following condition is satisfied: f1/f2 = 1.56.

In the six-piece microscope lens group of the first embodiment, the focal length of the second lens 120 is f2, the focal length of the third lens 130 is f3, and the following condition is satisfied: f2/f3 = -1.46.

In the six-piece microscope lens group of the first embodiment, the focal length of the third lens 130 is f3, the focal length of the fourth lens 140 is f4, and the following condition is satisfied: f3/f4 = -0.21.

In the six-piece microscope lens group of the first embodiment, the focal length of the fourth lens 140 is f4, the focal length of the fifth lens 150 is f5, and the following condition is satisfied: f4/f5 = 3.63.

In the six-piece microscope lens group of the first embodiment, the focal length of the fifth lens 150 is f5, the focal length of the sixth lens 160 is f6, and the following condition is satisfied: f5/f6 = -0.75.

In the six-piece microscope lens group of the first embodiment, the focal length of the first lens 110 is f1, the focal length of the third lens 130 is f3, and the following condition is satisfied: f1/f3 = -2.29.

In the six-piece microscope lens group of the first embodiment, the focal length of the second lens 120 is f2, the focal length of the fourth lens 140 is f4, and the following condition is satisfied: f2/f4 = 0.31.

In the six-piece microscope lens group of the first embodiment, the focal length of the third lens 130 is f3, the focal length of the fifth lens 150 is f5, and the following condition is satisfied: f3/f5 = -0.77.

In the six-piece microscope lens group of the first embodiment, the focal length of the fourth lens 140 is f4, the focal length of the sixth lens 160 is f6, and the following condition is satisfied: f4/f6 = -1.73.

In the six-piece microscope lens set of the first embodiment, the focal length of the third lens 130 is f3, the composite focal length of the first lens 110 and the second lens 120 is f12, and the following conditions are satisfied: f1/f23 = -0.13 .

In the six-piece microscope lens set of the first embodiment, the focal length of the second lens 120 is f2, and the combined focal length of the third lens 130 and the fourth lens 140 is f34, and the following conditions are satisfied: f2/f34 = -1.16 .

In the six-piece microscope lens set of the first embodiment, the composite focal length of the second lens 120 and the third lens 130 is f23, and the combined focal length of the fourth lens 140 and the fifth lens 150 is f45, and the following conditions are satisfied: F23/f45 = -10.25.

In the six-piece microscope lens set of the first embodiment, the combined focal length of the third lens 130 and the fourth lens 140 is f34, and the combined focal length of the fifth lens 150 and the sixth lens 160 is f56, and the following conditions are satisfied: F34/f56 = -0.78.

In the six-piece microscope lens set of the first embodiment, the composite focal length of the fourth lens 140 and the fifth lens 150 is f45, and the focal length of the sixth lens 160 is f6, and the following conditions are satisfied: f45/f6 = -0.97 .

In the six-piece microscope lens set of the first embodiment, the focal length of the first lens 110 is f1, and the combined focal length of the second lens 120, the third lens 130, and the fourth lens 140 is f234, and the following conditions are satisfied: f1 /f234 = 0.23.

In the six-piece microscope lens set of the first embodiment, the composite focal length of the second lens 120, the third lens 130, and the fourth lens 140 is f234, and the combined focal length of the fifth lens 150 and the sixth lens 160 is f56. The following conditions are met: f234/f56 = 6.26.

In the six-piece microscope lens set of the first embodiment, the composite focal length of the second lens 120 and the third lens 130 is f23, and the combined focal length of the fourth lens 140, the fifth lens 150, and the sixth lens 160 is f456. And the following conditions are met: f23/f456 = -18.17.

In the six-piece microscope lens set of the first embodiment, the focal length of the second lens 120 is f2, and the combined focal length of the third lens 130, the fourth lens 140, and the fifth lens 150 is f345, and the following conditions are satisfied: f2 /f345 = 0.84.

In the six-piece microscope lens set of the first embodiment, the focal length of the first lens 110 is f1, and the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, and the sixth lens 160 are combined. The focal length is f23456 and the following conditions are met: f1/f23456 = 1.65.

Refer to Table 1 and Table 2 below for reference.

Table 1 is the detailed structural data of the first embodiment of Fig. 1A, in which the unit of curvature radius, thickness and focal length is mm, and the surfaces 0-20 sequentially represent the surface from the object side to the image side. Table 2 is the aspherical surface data in the first embodiment, wherein the cone surface coefficients in the a-spherical curve equation of k, A, B, C, D, ... are high-order aspherical coefficients. In addition, the following table of the embodiments corresponds to the schematic diagram and the field curvature curve of each embodiment, and the definition of the data in the table is the same as the definitions of Table 1 and Table 2 of the first embodiment, and details are not described herein.

<Second embodiment>

2A and FIG. 2B, FIG. 2A is a schematic diagram of a six-piece microscope lens group according to a second embodiment of the present invention, and FIG. 2B is a six-piece microscope lens group of the second embodiment from left to right. Image curvature and distortion curve. As can be seen from FIG. 2A, the six-piece microscope lens assembly includes an aperture 200 and an optical group. The optical group sequentially includes a cover glass 291, a first lens 210, a positioning piece 292, and a second lens from the object side to the image side. 220, a third lens 230, a fourth lens 240, a fifth lens 250, a sixth lens 260, an infrared filter element 270, and an imaging surface 280, wherein the lens having a refractive power in the six-piece microscope lens group is Six pieces. The cover glass 291, the first lens 210, and the positioning piece 292 constitute a front group lens system. The second lens 220, the third lens 230, the fourth lens 240, the fifth lens 250, the sixth lens 260, and the infrared filter element 270 constitute a rear group lens system. The aperture 200 is disposed between the positioning piece 292 and the image side surface 222 of the second lens 220.

The cover glass 291 mainly protects and isolates the first lens 210 to prevent the first lens 210 from contacting the object to be detected (for example, biological fluid), and the cover glass 291 is made of glass, which is disposed on the object side and the first surface. The object side surface 211 of the lens 210 does not affect the focal length of the six-piece microscope lens group.

The first lens 210 has a positive refractive power and is made of a plastic material. The object side surface 211 is convex at the near optical axis 290, and the image side surface 212 is convex at the near optical axis 290, and the object side surface 211 and the image side are Surface 212 is aspherical.

The positioning piece 292 and the cover glass 291 position the first lens 210, and the positioning piece 292 is made of a plastic material, and is disposed on the image side surface 212 of the first lens 210 and the object side surface 222 of the second lens 220. The focal length of the six-piece microscope lens set is not affected.

The second lens 220 has a positive refractive power and is made of a plastic material. The object side surface 221 is convex at the near optical axis 290, and the image side surface 222 is convex at the near optical axis 290, and the object side surface 221 and the image side are Surfaces 222 are all aspherical.

The third lens 230 has a negative refractive power and is made of a plastic material. The object side surface 231 is concave at the near optical axis 290, and the image side surface 232 is concave at the near optical axis 290, and the object side surface 231 and the image side are Surfaces 232 are all aspherical.

The fourth lens 240 has a positive refractive power and is made of a plastic material. The object side surface 241 is convex at the near optical axis 290, and the image side surface 242 is concave at the near optical axis 290, and the object side surface 241 and the image side are Surface 242 is aspherical.

The fifth lens 250 has a positive refractive power and is made of a plastic material. The object side surface 251 is convex at the near optical axis 290, and the image side surface 252 is convex at the near optical axis 290, and the object side surface 251 and the image side are Surface 252 is aspherical.

The sixth lens 260 has a negative refractive power and is made of a plastic material. The object side surface 261 is convex at the near optical axis 290, and the image side surface 262 is concave at the near optical axis 290, and the object side surface 261 and the image side are Surface 262 is aspherical.

The infrared filter element 270 is made of glass and disposed between the sixth lens 260 and the imaging surface 280 without affecting the focal length of the six-piece microscope lens group.

Refer to Table 3 and Table 4 below.

In the second embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

With Table 3 and Table 4, the following data can be derived:

The six-piece microscope lens set provided by the invention can be made of plastic or glass for the cover glass, the positioning piece and the lens. When the lens material is plastic, the production cost can be effectively reduced, and when the lens is made of glass, the lens can be used. Increase the degree of freedom in the flexural force configuration of the six-piece microscope lens set. In addition, the object side surface and the image side surface of the lens in the six-piece microscope lens group may be aspherical, and the aspheric surface can be easily formed into a shape other than the spherical surface, and more control variables are obtained to reduce the aberration and thereby reduce the lens. The number used, therefore, can effectively reduce the overall length of the six-piece microscope lens set of the present invention.

In the six-piece microscope lens set provided by the present invention, in the case of a lens having a refractive power, if the surface of the lens is convex and the position of the convex surface is not defined, it indicates that the surface of the lens is convex at the near-optical axis; When the lens surface is concave and the concave position is not defined, it indicates that the lens surface is concave at the near optical axis.

The six-piece microscope lens set provided by the invention is more suitable for the optical system of moving focus, and has the characteristics of excellent aberration correction and good image quality.

In the above, the above embodiments and drawings are only the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, that is, the equivalent changes and modifications made by the scope of the present invention are all It should be within the scope of the patent of the present invention.

100, 200‧‧ ‧ aperture

110, 210‧‧‧ first lens

111, 211‧‧‧ object side surface

112, 212‧‧‧ image side surface

120, 220‧‧‧ second lens

121, 221‧‧‧ object side surface

122, 222‧‧‧ image side surface

130, 230‧‧‧ third lens

131, 231‧‧‧ object side surface

132, 232‧‧‧ image side surface

140, 240‧‧‧ fourth lens

141, 241‧‧‧ side surface

142, 242‧‧‧ image side surface

150, 250‧‧‧ fifth lens

151, ‧ ‧ ‧ ‧ side surface

152, 252‧‧‧ image side surface

160, 260‧‧‧ sixth lens

161, ‧ ‧ ‧ side surface

162, 262‧‧‧ image side surface

170, 270‧‧‧ Infrared filter components

180, 280‧‧ ‧ imaging surface

190, 290‧‧‧ optical axis

191, 291‧‧‧ coverslips

192, 292‧‧‧ Positioning film

f‧‧‧Focus of the six-piece microscope lens set

Object side numerical aperture of a NA‧‧‧ six-piece microscope lens set

MA‧‧‧Six magnification of the six-piece microscope lens set

F1‧‧‧The focal length of the first lens

F2‧‧‧The focal length of the second lens

f3‧‧‧The focal length of the third lens

F4‧‧‧The focal length of the fourth lens

f5‧‧‧Focus of the fifth lens

F6‧‧‧The focal length of the sixth lens

F23‧‧‧Combined focal length of the second lens and the third lens

F34‧‧‧Combined focal length of the third lens and the fourth lens

F45‧‧‧Combined focal length of the fourth lens and the fifth lens

f56‧‧‧Combined focal length of the fifth lens and the sixth lens

f234‧‧‧Combined focal length of the second lens, the third lens and the fourth lens

F345‧‧‧Combined focal length of the third lens, the fourth lens and the fifth lens

f456‧‧‧Combined focal length of the fourth lens, the fifth lens and the sixth lens

F23456‧‧‧Combined focal length of the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens

Fig. 1A is a schematic view showing a six-piece microscope lens group according to a first embodiment of the present invention. Fig. 1B is a graph showing the curvature of field and the distortion of the distortion of the six-piece microscope lens group of the first embodiment from left to right. 2A is a schematic view of a six-piece microscope lens set of a second embodiment of the present invention. 2B is a graph showing the curvature of field and the distortion of the distortion of the six-piece microscope lens group of the second embodiment from left to right.

Claims (20)

A six-piece microscope lens set comprising, from the object side to the image side, a first lens having a positive refractive power, the image side surface having a convex surface at a near optical axis, and at least one surface of the object side surface and the image side surface An aspherical surface; an aperture; a second lens having a positive refractive power, the object side surface being convex at the near optical axis, and at least one surface of the object side surface and the image side surface being aspherical; a third lens having a negative The refractive power is convex at the near-optical axis of the image side surface, and at least one surface of the object-side surface and the image-side surface is aspherical; a fourth lens having a positive refractive power, the image side surface having a concave surface at the near-optical axis, At least one surface of the object side surface and the image side surface is aspherical; a fifth lens having a positive refractive power, the image side surface having a convex surface at a near optical axis, and at least one surface of the object side surface and the image side surface being aspherical A sixth lens having a negative refractive power, the object side surface being convex at a near optical axis, and at least one surface of the object side surface and the image side surface being aspherical. The six-piece microscope lens set according to claim 1, wherein the first lens has a focal length of f1, the second lens has a focal length of f2, and satisfies the following condition: 1.0 < f1/f2 < 3.0. The six-piece microscope lens set according to claim 1, wherein the second lens has a focal length of f2, the third lens has a focal length of f3, and satisfies the following condition: -2.0 < f2/f3 < -0.8. The six-piece microscope lens set according to claim 1, wherein the focal length of the third lens is f3, the focal length of the fourth lens is f4, and the following condition is satisfied: -0.3 < f3/f4 < -0.1. The six-piece microscope lens set according to claim 1, wherein the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, and the following condition is satisfied: 3.0 < f4/f5 < 7.0. The six-piece microscope lens set according to claim 1, wherein the fifth lens has a focal length of f5, the sixth lens has a focal length of f6, and satisfies the following condition: -1.0 < f5/f6 < -0.5. The six-piece microscope lens set according to claim 1, wherein the focal length of the first lens is f1, the focal length of the third lens is f3, and the following condition is satisfied: -3.5 < f1/f3 < -2.0. The six-piece microscope lens set according to claim 1, wherein the second lens has a focal length of f2, the fourth lens has a focal length of f4, and satisfies the following condition: 0.1 < f2/f4 < 0.4. The six-piece microscope lens set according to claim 1, wherein the focal length of the third lens is f3, the focal length of the fifth lens is f5, and the following condition is satisfied: -1.1 < f3/f5 < -0.45. The six-piece microscope lens set according to claim 1, wherein the focal length of the fourth lens is f4, the focal length of the sixth lens is f6, and the following condition is satisfied: -4.0 < f4/f6 < -2.2. The six-piece microscope lens set according to claim 1, wherein the focal length of the first lens is f3, the combined focal length of the first lens and the second lens is f12, and the following condition is satisfied: -0.25 < f1/f23 < -0.05. The six-piece microscope lens set according to claim 1, wherein the focal length of the second lens is f2, the combined focal length of the third lens and the fourth lens is f34, and the following condition is satisfied: -1.5 <f2/f34 < -0.8. The six-piece microscope lens set according to claim 1, wherein the combined focal length of the second lens and the third lens is f23, and the combined focal length of the fourth lens and the fifth lens is f45, and the following conditions are satisfied: -16.0 <f23/f45 < -7.0. The six-piece microscope lens set according to claim 1, wherein the combined focal length of the third lens and the fourth lens is f34, and the combined focal length of the fifth lens and the sixth lens is f56, and the following condition is satisfied: -1.25 < f34/f56 < -0.60. The six-piece microscope lens set according to claim 1, wherein the fourth lens and the fifth lens have a combined focal length of f45, the sixth lens has a focal length of f6, and satisfies the following condition: -1.3 < f45/f6 < -0.65. The six-piece microscope lens set according to claim 1, wherein the focal length of the first lens is f1, the combined focal length of the second lens, the third lens and the fourth lens is f234, and the following condition is satisfied: 0.05 < f1 /f234 < 0.4. The six-piece microscope lens set according to claim 1, wherein the second lens, the third lens and the fourth lens have a combined focal length of f234, and the fifth lens and the sixth lens have a combined focal length of f56, and satisfy the following Condition: 4.0 < f234/f56 < 15.0. The six-piece microscope lens set according to claim 1, wherein the second lens and the third lens have a combined focal length of f23, the fourth lens and the fifth lens. The combined focal length of the lens and the sixth lens is f456, and the following conditions are satisfied: -30 < f23/f456 < -12. The six-piece microscope lens set according to claim 1, wherein the focal length of the second lens is f2, the combined focal length of the third lens, the fourth lens and the fifth lens is f345, and the following condition is satisfied: 0.55 < f2 /f345 < 1.1. The six-piece microscope lens set according to claim 1, wherein the focal length of the first lens is f1, and the combined focal length of the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens is f2345, And the following conditions are met: 1.2 < f1/f23456 < 3.2.