Confocal endoscope mini-microscope objective lens probe
Technical field
What the present invention relates to is a kind of device of optical technical field, specifically, is a kind of confocal endoscope mini-microscope objective lens probe.
Background technology
At present, confocal system is because clear, the continuous lamella scanner uni of its imaging image reorganization, multiple labeling technology, somatoscopy and acquisition quantification information etc., image contrast and resolution are all very high, in the widespread use of medical science every field, have brought into play great effect.But this system must take out the human internal organs tissue when tissues observed, carry out imaging and analysis then, and this had both increased patient's misery, had also prolonged interval between diagnosis, so can not be popularized clinically.This limitation has promoted the development of optical fiber Laser Scanning Confocal Microscope.Optical fiber has produced a type of attachment flexibly between the object lens of Laser Scanning Confocal Microscope and all the other systems, its permission system enters organization internal greatly, therefore can realize the live body co-focusing imaging.Confocal endoscope mini-microscope objective lens probe is one of gordian technique in the burnt endoscopic imaging system of copolymerization, and this system requirements will focus on structural light and get back in the simple optical fiber of town and country fibre bundle through the confocal endoscope mini-microscope objective lens probe coupling.
Through the literature search of prior art is found, Chinese patent application number is 200410059301.8, and open day is on February 9th, 2005, and this patent readme is: " the present invention has provided a kind of lens configuration of 100X oil immersion microcobjective.It gives to have on whole the smooth visual field of diffraction property.It comprises: first lens element that has one first lens at least; At least second lens element that has one second lens; At least the 3rd lens element that has one the 3rd lens; At least the 4th lens element that has one the 4th lens; At least the 5th lens element that has one the 5th lens; At least the 6th lens element that has one the 6th lens; At least the 7th lens element that has one the 7th lens; At least the 8th lens element that has one the 8th lens, these optical devices are arranged in first lens element to be enough to make the light height that enters second lens element to be compared with the light height that enters first lens element to reduce to the distance of second lens element, and the distance of the 5th lens element to the six lens elements is arranged in is enough to make the optical fiber height that enters the 6th lens element to compare increase with the light height that enters first lens element." its weak point is: 1, this design is to be used for general microscope, and volume ratio is bigger, can not enter inside of human body by endoscopic system, can not use with the imaging optical fiber bundle coupling; 2, the operating distance of this microcobjective is also very little, generally about the 100-200 micron; 3, the visual field of this microcobjective is also smaller.
Summary of the invention
The objective of the invention is to overcome the deficiencies in the prior art, a kind of confocal endoscope mini-microscope objective lens probe is provided, make its size Control enter inside of human body by endoscope path way, with light focusing the tissue in, and with the reflection optical convergence return whole optical system.
The present invention is achieved by the following technical solutions, the present invention includes: miniature microcobjective group, imaging optical fiber bundle and index-matching fluid, fill with index-matching fluid between imaging optical fiber bundle and the miniature microcobjective group, imaging optical fiber bundle is located at before the miniature microcobjective group; Described miniature microcobjective group pupil is positioned at infinity, and miniature microcobjective group is 1.0 in the numerical aperture of object space, and miniature microcobjective group is in the numerical aperture coupling of the simple optical fiber of the numerical aperture of image space and imaging optical fiber bundle.
Described miniature microcobjective group comprises: first lens element, second lens element, the 3rd lens element, the 4th lens element, the 5th lens element, the 6th lens element, the 7th lens element and the 8th lens element, first lens element is located at the foremost of miniature microcobjective group, after imaging optical fiber bundle, second lens element is located at after first lens element, the 3rd lens element is located at after second lens element, before the 4th lens element, the 5th lens element is located at after the 4th lens element, the 6th lens element is located at after the 5th lens element, before the 7th lens element, the 8th lens element is located at after the 7th lens element, and the front surface of the 8th lens element is soaked in water.
The integral diameter of described miniature microcobjective group is less than 5mm.
Described miniature microcobjective group adopts the brass packing, and the external diameter of brass is less than 7mm.
Described miniature microcobjective group has the specific (special) requirements except first lens element and the 8th lens element, and the other lenses element all adopts glass material design of the same race, and this can reduce cost greatly.
Described miniature microcobjective group pupil is positioned at infinity, so that can return the imaging optical fiber bundle same lighting fiber and not skew from the light of organizing reflected back.
The refractive index of described first lens element is considered the coupling of miniature microcobjective group and imaging optical fiber bundle, and first lens element is selected lower refraction materials for use, elects 1.5 as; First lens element is the plane near the surface of object plane, and second surface is a sphere, has positive light coke.The refractive index of described second lens element is 1.728, has positive light coke.The refractive index of described the 3rd lens element is 1.728, has positive light coke.Described the 4th lens element refractive index is 1.728, has negative power.Described the 5th lens element refractive index is 1.728, has positive light coke.Described the 6th lens element refractive index is 1.728, has positive light coke.Described the 7th lens element refractive index is 1.728, has positive light coke.Described the 8th lens element refractive index is 1.72, has the hardness of positive light coke, 720HK, can reduce to wait the damage that contacts generation with tissue.
Among the present invention, the divergent rays of the intrafascicular simple optical fiber outgoing of a branch of imaging fibre is entered miniature microcobjective group through index-matching fluid, described miniature microcobjective group comprises: first lens element, second lens element, the 3rd lens element, the 4th lens element, the 5th lens element, the 6th lens element, the 7th lens element and the 8th lens element.First lens element has positive light coke, and the light beam that will disperse is assembled to optical axis; Enter second lens element, because of second lens element has positive light coke, light continues to assemble to optical axis; Because of second lens element is the thick meniscus lens element, can revise the curvature of field; Then the light of assembling enters the 3rd lens element, and the 3rd lens element has positive light coke; And away from the curvature of object plane is infinitely great, and relative with first lens element can be revised spherical aberration; Convergence by first three each lens element reduces the angle of divergence of light beam; Converging ray enters the 4th lens element, and the 4th lens element has negative power, makes light depart from optical axis and propagates, and light is played the effect of expanding bundle, and the negative power of the 4th lens element has further been revised the elementary aberration of miniature microcobjective group; The 5th lens element has positive light coke; Will be from the divergent rays collimation of the 4th lens element, light is approximate to be parallel to optical axis, and the 5th lens element also is a meniscus shaped element, will further revise the curvature of field; The 6th lens element has positive light coke; Converging parallel is in the light of optical axis, and convergent angle is bigger; The 7th lens element has positive light coke; Further light is assembled, and increased convergent angle again; The 8th lens element is similar to packaged lens and has positive light coke, and focal length is shorter, and light is converged at a bit with very big angle, can improve the numerical aperture of total system so greatly.Because this mini-microscope objective lens is the imaging system that is used to enter the endoscopic system of human body, so its size is small, the integral diameter of miniature microcobjective group is less than 5mm, according to histocompatbility, miniature microcobjective group adopts the brass packing, and the external diameter of brass is less than 7mm.
The invention has the beneficial effects as follows: numerical aperture is big, can effectively suppress to come from the noise that diffuse reflection is the background radiation form; Structurally we adopt compact microminiaturization design, so physical dimension is little, can enter inside of human body by endoscope path way; For three-dimensional imaging, the operating distance of design is big, can arrive 450 microns; The visual field of design is also very big, is about 250 microns.The invention provides optical devices that under microsize, have high-caliber aberration correction.In addition the present invention also provide a kind of on whole visual field Strehal than (Strehal ratio: the ratio that peak strength in the diffraction pattern of peak strength and aberrationless dot image in the diffraction pattern of dot image of aberration is arranged.High Strehal ratio shows high-caliber aberration correction.) value is approximately equal to or greater than 0.95 optical devices.
Description of drawings
Fig. 1 is a structural representation of the present invention.
Fig. 2 is the design aberration curve figure at miniature microcobjective group monochromatic light difference place in the visual field.
Embodiment
As shown in Figure 1, the present invention includes: miniature microcobjective group 1, imaging optical fiber bundle 2 and index-matching fluid 3, described miniature microcobjective group 1 comprises: first lens element 4, second lens element 5, the 3rd lens element 6, the 4th lens element 7, the 5th lens element 8, the 6th lens element 9, the 7th lens element 10 and the 8th lens element 11, first lens element 4 is located at the foremost of miniature microcobjective group 1,5.63mm after imaging optical fiber bundle 2, second lens element 5 is located at first lens element 4 0.097mm afterwards, the 3rd lens element 6 is located at second lens element 5 0.257mm afterwards, 0.52mm before the 4th lens element 7, the 5th lens element 8 is located at the 4th lens element 7 0.597mm afterwards, the 6th lens element 5 is located at the 5th lens element 8 0.437mm afterwards, 0.05mm before the 7th lens element 10, the 8th lens element 11 is located at the 7th lens element 10 0.05mm afterwards, the front surface of the 8th lens element 11 is soaked in water, fill with index-matching fluid between imaging optical fiber bundle 2 and the miniature microcobjective group 1, imaging optical fiber bundle 2 is located at miniature microcobjective group 1 5.63mm before.
The integral diameter of described miniature microcobjective group 1 is less than 5mm.
Described miniature microcobjective group 1 pupil is positioned at infinity, so that can return the imaging optical fiber bundle 2 same lighting fiber and not skew from the light of organizing reflected back.
Described miniature microcobjective group 1 has the specific (special) requirements except first lens element 4 and the 8th lens element 11, and the other lenses element all adopts glass material design of the same race, and this can reduce cost greatly.
Described miniature microcobjective group 1 adopts the brass packing, and the external diameter of brass is less than 7mm.
Described miniature microcobjective group 1 is 1.0 in the numerical aperture of object space, in the numerical aperture coupling of the simple optical fiber of the numerical aperture of image space and imaging optical fiber bundle 2.
The refractive index of described first lens element 4 is considered the coupling of miniature microcobjective group 1 and imaging optical fiber bundle 2, and first lens element 4 is selected lower refraction materials for use, elects 1.5 as; First lens element 4 is the plane near the surface of object plane, and second surface is a sphere, has positive light coke.The refractive index of described second lens element 5 is 1.728, has positive light coke.The refractive index of described the 3rd lens element 6 is 1.728, has positive light coke.Described the 4th lens element 7 refractive indexes are 1.728, have negative power.Described the 5th lens element 8 refractive indexes are 1.728, have positive light coke.Described the 6th lens element 9 refractive indexes are 1.728, have positive light coke.Described the 7th lens element 10 refractive indexes are 1.728, have positive light coke.Described the 8th lens element 11 refractive indexes are 1.72, have the hardness about positive light coke, 720HK, can reduce to wait the damage that contacts generation with tissue.
As shown in Figure 2, the design aberration curve at miniature microcobjective group monochromatic light of the present invention difference place in the visual field, can clearly be seen that from this curve, differ for single wavelength and to have obtained good correction, only also have remaining coma and high-order to differ (each scale mark is meant 0.1 ripple among Fig. 2) in big field positions.A among Fig. 2 represents coaxial (0.000 size), and Wavefront aberration only is 0.08.Wavefront aberration among B among Fig. 2 (0.075 half-court), C (0.1 whole audience) and the D (0.125 whole audience) is about 0.3 ripple.These curves prove that this design is all well proofreaied and correct on whole visual field.The Strehal ratio of diffraction limit on axle of final design is 0.997, and field of view edge is 0.986, has proved that also aberration is well proofreaied and correct.