Apparatus for fixing solid immersion lens

The present invention disclosed herein relates to an apparatus for fixing a solid immersion lens (SIL) mounted in an objective lens of a thermal image microscope, and more particularly, to an apparatus for fixing an SIL, which controls a focal length using a screw tap and includes a flexible structure capable of maintaining a close contact between a specimen and the SIL.

Generally, there is known a technology of providing a hemispherical SIL having a top surface of a spherical type and a bottom surface of a flat type, which uses an evanescent wave so as to achieve high resolving power which was impossible due to a diffraction of light in a thermal image optical system including a plurality of functional lenses capable of accurately measuring the state of a specimen by applying an infrared ray to a subject.

As a related art about the apparatus for fixing an SIL, Korean Patent Application Publication No. 10-2008-0011814 (published on Feb. 11, 2008) discloses “optical head of apparatus for reproducing recording medium and method for manufacturing the same”. In this document, as shown in FIG. 1 , an adhesive material 130 is injected to combine an objective lens 120 and a lens holder assembly 110 equipped with a SIL 100 , and light reflected by a reflection mirror 140 is acquired by an image sensor. Thereafter, a tile component of the objective lens 120 is adjusted according to an interference pattern. In order to minutely adjust the tilt of the objective lens 120 , a piezoelectric linear motor 150 is coupled to a side surface of the lens holder assembly 110 , and then is driven before the adhesive material 130 is hardened, thereby controlling the location of the objective lens 120 according to the expansion and contraction of the piezoelectric linear motor 150 .

In a typical thermal image optical system including an SIL, as the SIL is applied to an infrared ray (IR) objective lens, there is a difficulty in adjusting the alignment of the optical axis and the focus by an apparatus of fixing the SIL in the optical system. Also, since a screw fastening force is delivered to the objective lens, the performance of the objective lens may be reduced.

Also, in the related art as described above, as the lens holder assembly equipped with the SIL is fixed to the objective lens with the adhesive material and the location of the objective lens is adjusted by the piezoelectric linear motor, a linear motor fastening force acts on the objective lens, reducing the performance of the objective lens. Usually, the mounting end portion of the SIL is close to the specimen within about 50 nm. Accordingly, in the general screw assembly structure and related art, when the end portion of the fixing apparatus and the specimen do not contact each other in a horizontal state, the specimen or the lens may be damaged.

Technical Objectives

One of the objectives of the present invention is to provide an apparatus for fixing an SIL, which includes a flexible structure fixing a barrel of an objective lens using an elastic body and maintaining a close contact between a specimen and the SIL, so as to enable an axial alignment of the objective lens of an existing thermal image microscope and prevent a deformation of a precision optical system inside the barrel.

Technical Solution

Embodiments of the present invention provide apparatuses for fixing an SIL in an SIL optical system, comprising: a first adapter equipped with the SIL, adjusting a distance from an IR objective lens and a focal length from a specimen by adjusting a location of the SIL, and in closely horizontal contact with the specimen; a second adapter screw-coupled to an inner surface of the first adapter and screw-coupled to an outer surface of a third adapter to pressurize or depressurize a first O-ring; the third adapter screw-coupled to inner surfaces of the second adapter and a fourth adapter, the first O-ring being disposed at one end portion thereof and a second O-ring being disposed at the other end portion thereof; the fourth adapter screw-coupled to the outer surface of the third adapter to pressurize or depressurize the second O-ring; the first and second O-rings elastically fixing an outer surface of a barrel of the IR objective lens by the expansion due to pressurizing forces of the second adapter and the fourth adapter; and an SIL holder mounting the SIL onto the first adapter.

In some embodiments, the first adapter may be formed to be a cylinder with a closed surface at one side thereof. The cylinder may have a plurality of slits performing a spring function at one side of the inner surface of the cylinder and may include a first screw part adjusting the distance from the IR objective lens and the focal length from the specimen at the other side of the inner surface of the cylinder while being coupled to the second adapter. The closed surface may have a through-hole mounted with the SIL at about the center of the closed surface and may allow a user to observe the specimen. The closed surface may have a plurality of screw holes for installing the SIL holder mounted with the SIL formed at a predetermined distance around the through-hole.

In other embodiments, the second adapter may be coupled to the third adapter and may be formed to have a cylindrical shape so as to compress the first O-ring to deform the O-ring. The second adapter may include a stopper part at one side thereof, surrounding a through-hole into which the barrel of the objective lens is inserted and a second screw part that pressurizes or depressurizes the first O-ring by coupling to the third adapter on the inner surface of the cylinder at the other side thereof. The second adapter may include a third screw part coupled to the first screw part of the first adapter along a predetermined length on the outer surface of the cylinder.

In still other embodiments, the third adapter may be coupled to the second adapter and the fourth adapter and may be formed to be a cylinder opened at both sides thereof so as to support the first and second O-rings deformed by a fastening force of the second and fourth adapters at both end portion thereof, and may include a fourth screw part formed along a whole length of the outer surface thereof.

In even other embodiments, the fourth adapter may be formed to have a cylindrical shape so as to pressurize or depressurize the second O-ring by coupling to the third adapter. The fourth adapter may be formed to be a cylinder with one side opened and may include a fifth screw part configured to couple to a fourth screw part of the third adapter on the inner surface thereof, and may include a stopper part at the other side thereof, surrounding a through-hole into which the barrel of the objective lens is inserted, whereby the fourth adapter is a component for reference position.

In yet other embodiments, the first and second O-rings may be formed of a highly elastic rubber material and may have the diameter of about a half of the difference between the outer diameter and the inner diameter of the third adapter in a free state where a pressurizing force does not act, and the SIL holder may be installed on a closed surface of the first adapter by a plurality of screws to fix the SIL to an optical axis.

Effects of the Invention

Since the apparatus for fixing an SIL is elastically coupled to an IR objective lens using an O-ring with an elastic force, the alignment of the optical axis and the adjustment of the focus can be easily achieved.

When an external force acts, the performance of the objective lens decreases easily. Since the apparatus for fixing an SIL is elastically coupled to the objective lens using an O-ring with an elastic force, the fastening force by screw coupling does not act on the objective lens. Accordingly, the performance reduction of an optical system can be prevented.

Also, a close contact is needed between the specimen and the bottom surface of the SIL. Accordingly, when the measurement surface of the specimen and the bottom surface of the SIL are not maintained at a horizontal state, a spring function is given to the apparatus for fixing an SIL. In this case, even though an inclination occurs on the specimen, the apparatus for fixing an SIL can become in horizontal contact with the specimen, and thus a distribution load can be evenly applied to the specimen. Accordingly, the specimen or the SIL can be prevented from being damaged.

FIG. 1 is a view illustrating a typical structure equipped with a solid immersion lens (SIL);

FIG. 2 is an exploded perspective view illustrating an apparatus for fixing an SIL according to an embodiment of the present invention;

FIG. 3 is a view illustrating an assembly relationship between an apparatus for fixing an SIL and a barrel according to an embodiment of the present invention;

FIG. 4 is a view illustrating a first adapter of an apparatus for fixing an SIL according to an embodiment of the present invention;

FIG. 5 is a view illustrating an SIL mounted in an apparatus for fixing an SIL according to an embodiment of the present invention;

FIG. 6 is a view illustrating an apparatus for fixing an SIL elastically fixed to a barrel, using an O-ring according to an embodiment of the present invention; and

FIG. 7 is a view illustrating a state of horizontal contact between an apparatus for fixing an SIL and a specimen according to an embodiment of the present invention.

Preferred embodiments of the present invention will be described below in more detail with reference to the accompanying figures.

As shown in FIGS. 2 and 3 , an apparatus for fixing an SIL according to an embodiment of the present invention may include a first adapter 1 , a second adapter 2 , a third adapter 3 , a fourth adapter 4 , a first O-ring 5 , a second O-ring 6 , and a SIL holder 7 . The apparatus for fixing an SIL may be fixed to an outer surface of a barrel 8 of an IR objective lens by an elastic force of the O-ring by coupling the third and fourth adapters 3 , 4 and then compressing the two O-rings 5 , 6 by a movement of a screw tap to allow the two O-rings 5 , 6 to expand toward an outer circumferential surface of the barrel 8 of the IR objective lens.

The first adapter 1 may have a plurality of slits 1 b that perform a spring function so as to be closely in horizontal contact with a specimen. An SIL may be disposed on the inner surface of the first adapter 1 while adjusting the focal length from the specimen by adjusting the distance between the SIL and the IR objective lens using a height adjustment by the screw tap that is coupled.

More specifically, the first adapter 1 , as shown in FIG. 4 , may be formed to have a cylindrical shape that has a closed surface 1 a at one side thereof and an opening at the other side thereof. The plurality of slits 1 b may be formed at a predetermined distance in a predetermined region of the circumference at the side of the closed surface 1 a of the cylinder. Also, a first screw part 1 c may be formed on the inner surface at the side of the opening of the cylinder to adjust the focal length from the specimen while being coupled to the second adapter 2 .

A transmission aperture 1 d for observing the specimen may be formed at the center of the closed surface 1 a to be mounted with the SIL 9 . Also, a plurality of screw holes 1 e for installing an SIL holder 7 equipped with the SIL may be formed at a predetermined distance around the transmission aperture 1 d.

The plurality of slits 1 b may be formed at a vertical wall of the cylinder by crossing connection parts if in which the slits 1 b are not formed. The plurality of slits 1 b may be arranged in six rows within a range of a third to a fourth of the length of the first adapter 1 . One slit 1 b may be formed to divide the circumference into three equal parts such that the connection parts if are disposed in a zigzag pattern at a predetermined distance.

As shown in FIG. 6 , since the first adapter 1 has one side or the whole thereof to be extended or contracted when an external force or an impact acts on the end portion of the first adapter 1 due to the plurality of slits 1 b , the first adapter 1 may have a shock absorbing function, i.e., spring function. Also, even though the specimen is not disposed to be horizontal, the specimen and the SIL may be allowed to be maintained at the horizontal state, allowing the specimen and the SIL to be close to each other in a horizontal state.

That is, even when an inclination occurs between the specimen and the SIL which need a close contact with each other, the slits 1 b formed in the apparatus for fixing an SIL may allow the specimen and the SIL to be in close contact with each other in a horizontal direction. Thus, when the SIL is allowed to be adhered closely to the specimen, an eccentricity may not occur, and thus a uniform distributed load, not a concentrated load, may act, thereby preventing the specimen and the SIL from being damaged.

Also, the closed surface 1 a of the first adapter 1 may be formed to incline about 95 degrees with respect to the vertical wall of the cylinder, and thus may form an inclination protrusion surface that protrudes in the opposite direction to the cylinder. A certain surface around the transmission aperture 1 d formed at the center of the protrusion surface may be formed to be a flat surface perpendicular to the central axis of the transmission aperture 1 d , allowing one side surface of the transmission aperture 1 d and the specimen to be adhered closely to each other in a horizontal direction.

As shown in FIGS. 2 and 3 , the second adapter 2 may be coupled to the third adapter 3 , and may be formed to have a cylindrical shape so as to compress the first O-ring 5 to deform the O-ring 5 . The second adapter 2 may include a stopper part 2 b at one side thereof, surrounding a through-hole 2 a into which a barrel is inserted, and a second screw part 2 c that pressurizes or depressurizes the first O-ring 5 by coupling to the third adapter 3 on the inner surface of the cylinder at the other side thereof. Also, the second adapter 2 may have a third screw part 2 d coupled to the first screw part 1 c of the first adapter 1 along a predetermined length on the outer surface of the cylinder. That is, the second screw part 2 c may be formed on the whole of the inner circumferential surface of the second adapter 2 . The third screw part 2 d coupled to the first adapter 1 may be formed on one side portion of the outer circumferential surface of the second adapter 2 , but a screw part may not be formed on the other side portion thereof.

As shown in FIGS. 2 and 3 , the third adapter 3 may be coupled to the second adapter 2 and the fourth adapter 4 . The third adapter 3 may move by fastening forces according to the screw coupling with the second and fourth adapters 2 , 4 . The third adapter 3 may pressurize the first and second O-rings 5 , 6 to deform the shape of the O-rings 5 , 6 . For this, the third adapter 3 may be formed to be opened at both sides thereof such that a second adhesion action occurs on the barrel 8 of the IR objective lens and the apparatus for fixing an SIL according to the shape change of the O-rings 5 , 6 . Also, a fourth screw part 3 a may be formed along the whole length of the outer circumferential surface thereof. The fourth screw part 3 a may be coupled to the second screw part 2 c of the second adapter 2 and a screw part of the fourth adapter 4 . The inner circumferential surface of the third adapter 3 may be formed to be flat without a screw part.

As shown in FIGS. 2 and 3 , the fourth adapter 4 may be a component for reference position, and may be formed to have a cylindrical shape so as to pressurize or depressurize the second O-ring 6 by coupling to the third adapter 3 . The fourth adapter 4 may have one side opened, and may have a fifth screw part 4 a coupled to the fourth screw part 3 a of the third adapter 3 on the inner surface thereof. The fourth adapter 4 may have a through-hole 4 b into which the barrel of the objective lens is inserted at the other side thereof. The fourth adapter 4 may include a stopper part 4 c formed around the through-hole 4 b to apply a fastening force by screw coupling to the second O-ring 6 .

As shown in FIGS. 2 and 3 , the first O-ring 5 may be formed of a highly elastic rubber material, and may be disposed between the second adapter 2 and the third adapter 3 to be changed in shape by a compressive force due to the screw coupling of the second and third adapters 2 and 3 . The diameter of the first O-ring 5 may be about a half of the difference between the outer diameter and the inner diameter of the third adapter 3 in a free state where a pressurizing force does not act such that a first adhesion action occurs on the barrel 8 of the IR objective lens and the apparatus for fixing an SIL due to the change in shape. That is, the first O-ring 5 may be formed to have a thickness equal to the thickness of the third adapter 3 .

As shown in FIGS. 2 and 3 , the second O-ring 6 may be formed of a highly elastic rubber material, and may be disposed between the third adapter 3 and the fourth adapter 4 to be changed in shape by a compressive force due to the screw coupling of the third and fourth adapters 3 , 4 . The diameter of the second O-ring 6 may be about a half of the difference between the outer diameter and the inner diameter of the third adapter 3 in a free state where a pressurizing force does not act such that the second adhesion action occurs on the barrel 8 of the IR objective lens and the apparatus for fixing an SIL due to the change in shape. That is, similarly to the first O-ring 5 , the second O-ring 6 may be formed to have a thickness equal to the thickness of the third adapter 3 .

As shown in FIG. 5 , the SIL holder 7 have a predetermined length, and may include an inclination part at one side thereof. The SIL may be fitted into the inclination part to be fixed. The SIL holder 7 may be fixedly installed by a screw hole 1 e formed in the closed surface 1 a of the first adapter 1 , and may serve to fix the SIL to the optical axis.

One embodiment of the present invention provides the apparatus for fixing an SIL including the first adapter, the second adapter, the third adapter, the first and second O-rings, and the SIL holder. The difficulties in adjusting the optical alignment and the focus can be overcome through the screw movement of the first adapter equipped with the SIL. Also, a reduction in performance of the objective lens caused by a screw fastening force acting on the objective lens can be prevented by coupling the apparatus for fixing an SIL to the barrel of the objective lens through the elastic expansive force of the O-ring. In addition, the horizontally close state between the SIL and the specimen can be maintained through the slits of the first adapter having a spring function, thereby improving the performance of the SIL and preventing the specimen and the SIL from being damaged.