JP2002031761A - Device and method for machining objective lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an objective lens capable of preventing the center of the visual field from deviating even if the lens is switched to the one having a different magnification. SOLUTION: A mounting screw 24 to be screwed to the supporting screw part of a revolver and a mounting face 23 to be buttingly attached to the attaching face of the revolver are worked for the objective lens (the lens) 1. The lens 1 is equipped with an optical system 9 for emitting parallel light beams toward the lens 1, an observation system 14 that has a sample 10 for forming an image through the lens 1 and that observes a spot formed on the sample 10, a chuck 2 for holding the lens 1, a spindle 5 for rotating the chuck 2, a position adjusting mechanism 4 for adjusting a relative position between the chuck 2 and the spindle 5 so as to make the sample 10 coincide with the focal position of the lens 1, a tool 16 for working the mounting face 23 of the lens 1 with a space kept constant between the sample 10 and the mounting face 23 of the lens 1, and a tool 18 that is arranged separately from the mounting face working tool 16 and that is for working the mounting screw 24 of the lens 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing apparatus and a processing method for processing an objective lens used for an optical device such as a microscope.

[0002]

2. Description of the Related Art In the production of microelectronic parts and the like, inspection is performed using optical equipment such as a microscope. In this operation, first, a measurement point is positioned in the field of view using a low-magnification objective lens, and then the revolver is rotated to switch to a high-magnification objective lens for measurement. In such an operation, due to an error in the optical system of the objective lens, when switching from the low-magnification objective lens to the high-magnification objective lens, the center of the field of view may be deviated, resulting in a deviated measurement location or defocus. In such a case, it is necessary to switch to a low-magnification objective lens again in order to align the center of the field of view, and to perform positioning and focusing again.

In order to eliminate such a complicated operation, an optical device such as a microscope is provided with an automatic positioning mechanism and an automatic focusing mechanism. FIG. 5 shows a microscope provided with such a mechanism described in Japanese Patent Application Laid-Open No. 5-88091.

This microscope has a function of automatically moving the sample stage 104 so that the sample 103 is focused. In order to realize this function, in addition to the eyepiece lens 105 and the objective lens 101, , Imaging device 10
It has a 6-transmission flat plate 107 and a control device 110.

[0005] The transmission plane plate 107 is provided between the eyepiece 105 and the objective lens 101, and is inserted into and removed from the optical path between the lenses 105 and 101 by being rotated by the pulse motor 108. The pulse motor 108 is controlled by the control device 110.

The sample stage 104 is connected to a pulse motor 120 controlled by a control device 110.
In accordance with a command from the control device 110, it moves up and down in the optical path. The image sensor 106 is fixed to the lens barrel of the microscope so as to be located above the eyepiece 105, and after its output signal is amplified by the video amplifier 109,
It is sent to the control device 110. The control device 110
U (processing device) 111, ROM 112, RAM 113,
Bus line 114, motor drivers 115 and 116, A
A / D converter 117 is provided.

In this microscope, the sample stage 104 is moved by the control device 110, and the image sensor 106 measures the contrast values when the transmission plane plate 107 is inserted and when the transmission flat plate 107 is removed, and the control device 110 controls the contrast values. Compare values. The focal point is obtained from this comparison value, and the sample stage 104 is moved to that position to automatically focus.

[0008]

However, a microscope having a mechanism for automatically focusing as shown in FIG. 5 has a problem that the number of components is increased, the structure is complicated, and the cost is high. On the other hand, when the observer manually adjusts the center of the visual field, skill is required, and it is necessary to finely adjust the movement of the sample stage when performing focusing, which is a burden upon observation. In addition, there is a problem that the tact time becomes long.

The present invention has been made in view of the above-mentioned conventional problems. When observing or measuring an object to be measured, the object can be obtained without using an automatic positioning mechanism or an automatic focusing mechanism. An object of the present invention is to provide a processing apparatus and a processing method for processing an objective lens which can perform observation and measurement without switching and focusing again when the lens is switched from low magnification to high magnification. And

[0010]

When the objective lens attached to the revolver of the optical instrument is switched from low magnification to high magnification, the center of the field of view and the focus are shifted depending on each of the revolvers. This is because the mounting angle is deviated or the distance from the focal position of the objective lens to the mounting surface of the objective lens is deviated. In the present invention, the mounting surface and the mounting screw portion on the revolver are set so that the distance from the revolver mounting position or the revolver mounting angle of the objective lens to the mounting surface from the focal position of the objective lens to the mounting surface is always the same between different objective lenses. It is to be processed.

That is, the object lens processing apparatus according to the first aspect of the present invention is an apparatus for processing an objective lens into a mounting screw portion screwed to a support screw portion of a revolver and a mounting surface applied to a mounting surface of the revolver. An optical system that irradiates the objective lens with parallel light, an observation system that has a specimen that transmits an image through the objective lens, and observes a spot formed on the specimen, and a chuck that holds the objective lens. A spindle for rotating the chuck, a position adjustment mechanism for adjusting a relative position between the chuck and the spindle so that the focal position of the sample and the objective lens coincide, and a constant interval between the sample and the mounting surface of the objective lens. A mounting surface processing tool for processing the mounting surface of the objective lens while maintaining the same, and a mounting screw portion processing tool for processing the mounting screw portion of the objective lens which are separately disposed from the mounting surface processing tool. For example, characterized in that is.

In the present invention, the position is adjusted so that the focal point of the sample and the objective lens coincide with each other, and the mounting surface is machined while keeping the distance between the sample and the mounting surface of the objective lens constant. In this processing, the distance between the specimen and the mounting surface of the objective lens is always constant. Therefore, even if a different objective lens is processed, the distance between the focal position and the mounting surface is always constant. For this reason, when the processed objective lens is mounted on the revolver of the microscope, the direction with respect to the revolver is always in a predetermined direction, so that even when the objective lens is switched, the center of the field of view becomes constant, and the focus does not shift.

In such an invention, an expensive automatic positioning mechanism and an automatic focusing mechanism are not required, and re-positioning and focusing are not required, so that the tact time can be reduced.

According to a second aspect of the present invention, in the first aspect of the present invention, the observation system and the mounting surface processing tool are integrated with each other with the distance between the sample and the mounting surface of the objective lens kept constant. And is movable along the optical path of the parallel light.

In the present invention, since the observation system and the mounting surface processing tool can be integrally moved, the mounting surface processing tool always keeps the distance between the specimen and the mounting surface of the objective lens constant. , The mounting surface can be processed, and the adjustment of the distance between the specimen and the objective lens can be simplified.

According to a third aspect of the present invention, there is provided a method of processing an objective lens, wherein the mounting screw portion screwed to the support screw portion of the revolver and the mounting surface applied to the abutment surface of the revolver are formed into the objective lens. The parallel light applied to the objective lens is imaged on the sample, the focus position of the sample and the objective lens are matched, and the mounting screw portion and the space between the sample and the mounting surface of the objective lens are kept constant. The mounting surface is machined.

Since the objective lens is machined while keeping the distance between the specimen and the mounting surface of the objective lens constant while keeping the focal position of the specimen and the objective lens coincident with each other, even if the objective lens is a different objective lens, The distance from the mounting surface is always constant. For this reason, even if the objective lens is mounted on the revolver of the microscope and the objective lens is switched, the center of the visual field becomes constant, and the focus does not shift.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to embodiments shown in the drawings. In each of the embodiments, the same elements are denoted by the same reference numerals and correspond to each other.

(Embodiment 1) FIG. 1 shows a processing apparatus according to Embodiment 1 of the present invention, and FIG. 2 shows a state in which an objective lens is mounted on a revolver.

The objective lens 1 has a lens group (not shown) inside the lens barrel 1a. As shown in FIG.
A mounting surface 23 and a mounting screw portion 24 are formed in the upper part of the mounting surface. The revolver 25 has a plurality of contact surfaces 25a for attaching the objective lens 1 and a plurality of support screw portions 25b formed along the circumferential direction. The objective lens 1 is mounted on the revolver 25 by screwing the mounting screw portion 24 to the support screw portion 25b of the revolver 25 and applying the mounting surface 23 to the abutting surface 25a. Therefore, the revolver 25
The mounting position and mounting direction of the objective lens 1 with respect to are determined by the mounting surface 23 and the mounting screw portion 24.

As shown in FIG. 1, the processing device includes a spindle 5 and a chuck 2 of a lathe, an optical system 9 and an observation system 14.
And a mounting surface processing tool (mounting surface cutting tool) 16 and an installation screw portion processing tool (mounting screw portion cutting tool) 18.

The chuck 2 holds the objective lens 1 by chucking the lens barrel 1a of the objective lens 1 to be processed. The chuck 2 is provided with a slit, and a buffer material 3 made of a non-metallic material such as Bakelite or Delrin (trade name) is attached to a portion that comes into contact with the objective lens 1 so that the objective lens 1 can be attached at the time of chucking. So as not to hurt. The objective lens 1 to be chucked has a lens group incorporated in the lens barrel 1a, and a small amount of cutting margin remains on the mounting surface 23 and the mounting screw portion 24.

The spindle 5 rotates the chuck 2. The spindle 5 is adjusted so that the deflection in the plane direction and the vertical direction is minimized. This is to improve the surface accuracy of the mounting surface 23 when the mounting surface 23 of the objective lens 1 is processed by the mounting surface cutting tool 16 which is a mounting surface processing tool described later. Further, the deviation of the degree of parallelism between the parallel light from the optical system 9 and the central axis of the spindle 5 is also adjusted with submicron-order accuracy.

The spindle 5 is a motor (not shown).
However, in order to suppress thermal displacement of the entire apparatus due to heat generated by the motor, a stand (not shown) is provided separately.
It is further cooled by air. The form of the spindle 5 may be a combination of bearings, a form using an air spindle, or another form.

A position adjusting mechanism 4 is provided between the spindle 5 and the chuck 2. The position adjusting mechanism 4 adjusts the relative position between the spindle 5 and the chuck 2 (objective lens 1) by adjusting the chuck 2 or the objective lens 1 with respect to the spindle 5 in the shift and tilt directions. Then, in this adjusted state, the chuck 2, that is, the objective lens 1 is fixed. As a structure for fine adjustment, a structure using a guide and a micro head, a structure using a magnet, and the like can be selected.

FIG. 3 shows an example of a position adjusting mechanism for performing adjustment using a guide and a micro head. In the position adjusting mechanism 50, a tilt adjusting stage 53 in the XZ direction is provided on the XY stage 51. The tilt adjustment stage 53 in the XZ direction rotates about a guide shaft 52 provided on the XY stage 51. One side of the tilt adjustment stage 53 sandwiching the guide shaft 52 is urged by a spring 54, and a micro head 55 is mounted on the other side. In this structure, the tilt adjustment stage 53 is tilted in the XZ direction by rotating the micro head 55, so that tilt adjustment in the same direction can be performed.

Although not shown, a guide shaft in a direction perpendicular to the XZ-direction tilt adjustment stage 53 is provided on the tilt-adjustment stage 53, and a YZ-direction tilt adjustment stage that rotates about the guide shaft is provided.
Then, the micro head is rotated to perform tilt adjustment in the YZ directions. Thereby, tilt adjustment in three directions of XYZ can be performed.

The optical system 9 irradiates the objective lens 1 with parallel light, and includes a laser 6, a lens 7, and a PBS (polarizing beam splitter) 8. It is preferable to use a He-Ne laser having a wavelength of 633 nm as the laser 6.

The observation system 14 includes the sample 1 from the objective lens 1 side.
0, collimating lens 11, imaging lens 12, CCD1
3 are arranged in order along the parallel light. A monitor 15 is connected to the CCD 13.

The sample 10 is composed of a half mirror that reflects a part of the parallel light from the optical system 9 and transmits a part of the parallel light, and is arranged so as to be orthogonal to the parallel light from the optical system 9. The CCD 13 projects a spot transmitted through the sample 10 and formed by the imaging lens 12 on a monitor 15. Adjustment is made at the time of manufacturing the apparatus so that this spot is located at the center of the monitor 15. Further, it has an adjustment mechanism (not shown) that can be adjusted in the optical axis direction.

The observation system 14 can be adjusted vertically along the optical path of the parallel light so as to minimize the spot projected on the monitor 15. In this embodiment, the mounting surface cutting bit 16 and the observation system 14 are L
The observation system 14 and the mounting surface cutting tool 16 are integrally movable along the optical path. In addition, since the observation system 14 and the mounting surface cutting tool 16 are integrated by the connecting arm 26, the distance from the upper surface of the sample 10 to the mounting surface 23 of the objective lens 1 is always kept constant. Can be.

The mounting surface cutting tool 16 is movable along one axis in the plane direction, and is provided with a moving shaft (not shown) for that purpose. The mounting surface cutting tool 16 is driven by a motor 17 to cut a fixed amount of the mounting surface 23 of the objective lens 1. The moving direction of the mounting surface cutting tool 16 is positioned by a measuring device (not shown) at the time of mounting the device so as to be exactly perpendicular to the center axis of the spindle 5.

The mounting surface cutting tool 16 is integrated with the observation system 14 by an L-shaped connecting arm 26, and the distance between the specimen 10 of the observation system 14 and the mounting surface cutting tool 16 is always constant. Thereby, which objective lens 1
Is also set so that the focal position, that is, the position between the upper surface of the sample 10 and the mounting surface 23 (the mounting surface cutting tool 16) is constant. In addition, as a material of the mounting surface cutting tool 16, a single crystal diamond, a hard metal,
High speed steel or the like can be used. Also, at the time of setup, it is set after positioning by a tool presetter or the like.

The mounting thread cutting bit 18 is provided separately from the mounting face cutting bit 16 and has an NC control motor 19.
And the objective lens 1 is cut. The control motor 19 has a first motor 19a and a second motor 19b that control movement in two orthogonal directions, up and down and left and right. This cutting tool 18 is also used for mounting surface cutting tool 1.
As in step 6, the tool is set after positioning with the tool presetter during setup. The left and right movement directions of the cutting tool 18 are also positioned so as to be perpendicular to the rotation axis of the spindle 5.

Processing by the mounting screw part cutting tool 18 is as follows.
Peripheral processing, screw cutting and finishing are performed. For this reason, in this embodiment, a cutting tool is used in which two blades for outer diameter machining and thread cutting are integrated. Also, when switching between bright field screws and dark field screws,
By setting on the NC side, it is possible to cope with this by changing during setup.

As described above, by using the two types of cutting tools, the cutting screw 18 for the mounting screw portion and the cutting tool 16 for the mounting surface, the heat of the cutting tool generated during the processing of the mounting screw 24 in the preceding stage cuts the mounting surface 23. Without being transmitted when
The length of the objective lens 1 is extended by the cutting heat and the specimen 1
It is possible to prevent the distance from the upper surface of the zero to the mounting surface from changing.

Next, a working method according to this embodiment will be described.

The objective lens 1 is held by the chuck 2 by inserting the lens barrel 1 a of the objective lens 1 into the chuck 2 and closing the chuck 2. By irradiating the parallel light from the optical system 9, the image of the parallel light from the optical system 9 is monitored by the monitor 15.
Projected on. Then, while observing the monitor 15, the spindle 5 is rotated and the position is adjusted by the position adjusting mechanism 4 so that the rotation center of the image is located at the center of the monitor 15, and the position is fixed. By adjusting the rotation center of the image so that it is located at the center of the monitor 15, the direction of the focal point of the objective lens 1 is always constant when the objective lens 1 is mounted on the revolver 25 with the mounting screw portion 24.

In this state, by pressing a start switch (not shown), the mounting surface cutting tool 16 cuts the end surface of the mounting surface 23 of the lens barrel 1a. Then, the outer periphery of the mounting screw portion 24 is cut by the outer diameter machining bit of the mounting screw portion cutting bit 18. When the outer circumference cutting is completed,
The mounting screw 24 is cut by cutting with the screw cutting bit of the mounting screw cutting bit 18.

When the next objective lens 1 is to be cut, the processed objective lens 1 is removed from the chuck 2, the same setup is performed, and then the processing is performed. Thus, the distance from the focal point to the mounting surface 23 can be kept constant regardless of which objective lens 1 is processed. Therefore, even if the observer attaches the objective lens 1 to an optical device such as a microscope and switches from low magnification to high magnification, the focus is not shifted and the center of the visual field can be kept constant. Therefore, the operability at the time of observation and measurement is improved, and an automatic focusing mechanism and a moving positioning mechanism having a complicated structure are not required.

(Embodiment 2) FIG. 4 shows an objective lens processing apparatus according to Embodiment 2 of the present invention. In this embodiment, an adjusting motor 21 is connected to a position adjusting mechanism 4 arranged between the chuck 2 and the spindle 5.
The adjusting motor 21 includes a first motor 21a and a second motor 21.
b, and controls the position adjustment mechanism 4 in at least two directions.
The two motors 21a and 21b are connected to the control device 20. The spot formed on the sample 10 is observed on the monitor 15, and the position is fed back by the control device 20 so that the spot is located at the center of the monitor 15. It can be positioned to be located.

In addition to the above, in this embodiment, a connecting arm 26 for connecting the observation system 14 and the mounting surface cutting bite 16 is supported by the vertically moving motor 22. The vertical movement motor 22 controls the observation system 14 and the mounting surface cutting tool 16 so that they can move up and down along the optical path of the parallel light.

By providing the vertical movement motor 22 in this manner, image processing is performed in the control device 20 so that the spot on the monitor 15 has a minimum diameter, and the mounting surface cutting tool 16 is positioned at a focused position. Can be. At this time,
Since the observation system 14 is connected by the connection arm 26, the observation system 14 also moves integrally with the mounting surface cutting tool 16. Therefore, the mounting surface 23 can be machined while the mounting surface 23 of the sample 10 and the objective lens 1 is kept constant.

In such an embodiment, the tact time for manufacturing the objective lens 1 can be reduced in order to correct the position shift and the focus shift.

[0045]

According to the first aspect of the present invention, after adjusting the sample of the observation system and the focal position of the objective lens so as to machine the mounting surface and the mounting screw portion of the objective lens, a microscope or the like is used. When the objective lens is attached to the optical device and the objective is changed from low magnification to high magnification by rotating the revolver, the center of the field of view does not shift, it is not necessary to search for the measurement point again, and not only is the operability improved Since an automatic positioning mechanism is not required, the configuration of an optical device such as a microscope to which an objective lens is attached can be simple and inexpensive.

Also, since there are two types of tools, a mounting surface processing tool and a mounting screw processing tool, the heat of the screw processing tool generated during the screw processing affects the cutting of the mounting surface of the objective lens. Therefore, it is possible to prevent the total length of the objective lens from being extended by the influence of heat and defocusing. Similarly, since the spindle is separated from the mounting surface processing tool and the specimen, it is possible to prevent the total length of the objective lens from being extended due to the influence of heat generated from the spindle and defocusing.

According to the second aspect of the present invention, in addition to having the same effect as the first aspect of the present invention, since the observation system and the mounting surface processing tool move integrally, the mounting of the sample and the objective lens is performed. The mounting surface can be machined while keeping the distance to the surface constant, and the adjustment of the distance between the specimen and the objective lens can be simplified.

According to the third aspect of the present invention, the objective lens is machined with the focal position of the specimen and the objective lens matched and the interval between the specimen and the mounting surface of the objective lens is kept constant. Even if the objective lens is used, the distance between the focal position and the mounting surface is always constant. Therefore, even when the objective lens is mounted on the revolver of the microscope and the objective lens is switched, the center of the field of view is constant, and the focus does not shift. .

[Brief description of the drawings]

FIG. 1 is a front view showing a processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a partially broken front view showing a state where an objective lens is attached to a revolver.

FIG. 3 is a front view of a position adjusting mechanism.

FIG. 4 is a front view illustrating a processing apparatus according to a second embodiment of the present invention.

FIG. 5 is a block diagram of a conventional microscope having an automatic adjustment function.

[Description of Signs] 1 Objective lens 2 Chuck 5 Spindle 9 Optical system 10 Specimen 14 Observation system 16 Mounting surface cutting tool 18 Mounting screw part cutting tool 23 Mounting surface 24 Mounting screw part

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toshiharu Tsuhata F-term (reference) 2H087 KA09 LA01 NA00 in Olympus Optical Co., Ltd. 2-34-2 Hatagaya, Shibuya-ku, Tokyo

Claims (3)

[Claims] 1. An apparatus for processing a mounting screw portion screwed to a support screw portion of a revolver and a mounting surface applied to a mounting surface of the revolver into an objective lens, wherein the optical system irradiates the objective lens with parallel light. And an observation system for observing a spot formed on the specimen through an objective lens and forming an image, a chuck for holding the objective lens, a spindle for rotating the chuck, the specimen and the objective lens A position adjustment mechanism for adjusting the relative position between the chuck and the spindle so that the focal position of the objective lens coincides with that of the chuck, and a mounting for processing the mounting surface of the objective lens while maintaining a constant distance between the sample and the mounting surface of the objective lens. An object lens processing apparatus, comprising: a surface processing tool; and a mounting screw processing tool that is separately provided from the mounting surface processing tool and processes the mounting screw of the objective lens. 2. An observation system and a mounting surface processing tool are integrally movable along the optical path of the parallel light while maintaining a constant distance between the sample and the mounting surface of the objective lens. 2. The apparatus for processing an objective lens according to claim 1, wherein: 3. A method of processing a mounting screw portion screwed to a support screw portion of a revolver and a mounting surface applied to a mounting surface of a revolver into an objective lens, wherein the parallel light irradiated on the objective lens is sampled. The object is characterized in that the mounting screw portion and the mounting surface are machined while keeping the distance between the sample and the mounting surface of the objective lens constant while keeping the focus position of the sample and the objective lens coincident with each other. How to process the lens.