JP2010223807A - Reference lens-barrel unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reference lens-barrel unit which facilitates assembling and adjusting operations, without fine adjusting mechanisms, in order to enable a user to concentrate on the operation of an interferometer. <P>SOLUTION: A first lens-barrel and a second lens-barrel are assembled in a fitting fashion, and all of a reference optical path lens, a reference mirror and a compensation element are fixed to the first lens-barrel so as to be integrated. The reference mirror is arranged so as to be tilted at several angles with respect to an optical axis of the reference lens-barrel unit. The first lens-barrel has a guide, and the guide is moved along a groove formed on the second lens-barrel, thereby enabling a relative position between the first lens-barrel and the second lens-barrel to be adjusted. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a reference barrel unit, for example, a reference barrel unit used for an interferometer.

  Conventionally, in the microscope light source device of Patent Document 1, for example, a point light source collector lens unit corresponding to a light source to be used is inserted into a fixed portion of a lamp house and is detachably attached. In the collector lens unit for point light source, the collector lens is held on the same optical axis, and the reflection mirror is held via the mirror holding member.

  In FIG. 1 of Patent Document 2, line numbers 0032 and 0042 to 0041, a detection block as a detection unit, a lens barrel unit, and a scanning block are detachably provided on the microscope main body of the scanning laser microscope system.

  In the conventional interferometer, a mechanism for adjusting the inclination of the reference mirror with respect to the plane perpendicular to the optical axis is indispensable in order to cope with the change of the measurement object or the change of the objective lens. In particular, in an interferometer that has to be adjusted so as to reduce the number of interference fringes, these adjustment mechanisms are necessary functions.

  However, in the interference fringe analysis in which the object to be measured is specified, the height of the object to be measured is not changed, and the number of interference fringes is required to some extent, the desired number of interference fringes is generated, It is also possible to fix the reference mirror at a certain angle.

  In addition, when white light or multiple light sources are used as the light source of the interferometer, or when a line light source or a surface light source is used, only the reference mirror can be used for the light beam returning from the object surface through the object and the reference mirror. When the reflected light beam interferes, there is a difference between the principal rays of the two light beams, so that a linear interference fringe cannot be obtained, resulting in a curved interference fringe. In order to obtain a linear interference fringe, a lens or cylinder lens and a dispersion compensator are required in front of the reference mirror. Since these are individually adjusted, it takes time to assemble and adjust, and the structure becomes complicated.

Utility Model Registration No. 2561305 JP 2004-86009 A

  In Patent Document 1, the fastener must be fixed by engaging the fastener with the groove.

  In Patent Document 2, the detection block, the lens barrel unit, and the scanning block must be fixed with screws or the like.

  In both Patent Documents 1 and 2, it takes time and effort to assemble and adjust.

  Further, in Patent Document 2, the mirror is inclined and disposed, but since the inclination angle is clear, the unit is configured so that the inclination can be easily adjusted. However, it is difficult to adjust the slight inclination angle, which is extremely difficult to adjust the inclination, and it has been desired to reduce it. So far, the reduction of adjustment work has not been realized for a long time.

  Therefore, an object of the present invention is to provide a reference barrel unit that can be easily assembled and adjusted without using a fine adjustment mechanism and can focus on the work of an interferometer.

  Further, another object of the present invention is limited to the minimum necessary adjustment work such as irradiation light for irradiating light to the non-measurement object surface and the optical axis of the reference light, and no other adjustment work is required. A reference barrel unit is provided.

  In order to solve the above-described problems, the solving means of the present invention is exemplified as follows.

  For example, in the first aspect of the invention, the first lens barrel and the second lens barrel are assembled so that the reference optical path lens, the reference mirror, and the compensation element are all fixed to the first lens barrel in advance and integrated. It is the reference lens barrel unit characterized by the above.

  According to a second aspect of the present invention, in the reference barrel unit according to the first aspect of the present invention, the reference mirror unit is characterized in that the reference mirror is inclined at several degrees with respect to the optical axis of the reference barrel unit. .

  According to a third aspect of the present invention, in the reference lens barrel unit according to the first aspect, the first lens barrel in which the reference optical path lens, the reference mirror, and the compensation element are fixed and integrated in advance has a guide, The reference barrel unit is characterized in that the guide moves along a groove formed in the second barrel so that the relative position between the first barrel and the second barrel can be adjusted. .

  According to a fourth aspect of the present invention, in the reference barrel unit according to any one of the first to third aspects, the reference mirror can be replaced with a mirror having a different reflectance. .

  A fifth aspect of the present invention is an interferometer to which the reference barrel unit according to any one of the first to fourth aspects is detachably mounted.

  The present invention has the following effects.

1) The structure of the reference optical path of the interferometer can be simplified.

2) Since the first lens barrel integrally forms one component, the number of component parts of the reference lens barrel unit is small. Therefore, the assembly adjustment process is simplified when the interferometer is operated.

3) Since the number of components is small, the manufacturing cost can be reduced.

4) Since the structure is simple, the space can be reduced.

5) Since the reference mirror can be fixed accurately in advance, the stability of the apparatus and measurement is improved.

6) Since the reference mirror can be fixed firmly in advance, the work of adjusting the reference mirror can be omitted during the operation of the interferometer, and the usability is improved.

  The reference mirror is fixed by any fixing means such as a leaf spring and an adhesive.

  In addition, the optical components (reference mirror, lens, dispersion compensation plate) on the reference optical path are fixed to the first lens barrel in advance, and the first lens barrel and the second lens barrel are further fixed to unitize the entire reference unit. Thus, since the interference fringes can be focused only by moving the reference unit in the optical axis direction, the operation can be simplified.

  Further, according to the present invention, assembly and adjustment can be easily performed without a fine adjustment mechanism, and therefore, the work of the interferometer can be focused.

  Further, it is limited to the minimum necessary adjustment work such as irradiation light for irradiating light to the non-measurement object surface and optical axis alignment of the reference light, and other adjustment work is not required.

1 shows an outline of an example of an interferometer provided with a reference barrel unit according to the present invention. 1 shows an example of a reference barrel unit according to the present invention. 3 shows a longitudinal section of the reference barrel unit shown in FIG. 6 shows a modification of the reference barrel unit according to the present invention. Explanatory drawing which shows the condition of the preliminary adjustment of the 1st barrel of a reference barrel unit. 6 shows another modification of the reference barrel unit according to the present invention. Another modification of the reference barrel unit according to the present invention will be described.

  The interferometer will be described with reference to FIG.

  Light emitted from the light source unit 1, for example, coherent light, is split into two lights by the beam splitter 4 via the lenses 2 and 3.

  One light (irradiation light) that has passed through the beam splitter 4 is reflected by the sample surface (not shown) through the objective lens 5 and returns to the beam splitter 4 through the objective lens 5 again.

  The other light (reference light) reflected by the beam splitter 4 reaches the reference barrel unit 6, is reflected by the reference mirror 7 in the unit, and returns from the reference barrel unit 6 to the beam splitter 4 again. .

  The returned irradiation light and reference light are superimposed on the beam splitter 4, and both are imaged as interference fringes by an imaging element 9 such as a CCD via the imaging lens 8, and the shape of the sample surface is observed and imaged.

  In addition to the reference mirror 7 described above, a reference optical path lens 10 and a dispersion compensation plate (compensation element) 11 are attached and fixed to the reference barrel unit 6.

  Preferably, the reference mirror 7 is installed in the reference barrel unit 6 with an inclination of, for example, about 5 degrees. Note that the inclination angle of the reference mirror 7 is not limited to the above value, and may be several degrees.

  Hereinafter, the reference barrel unit 6 will be described in detail with reference to FIGS.

  The reference optical path lens 12 is fixed to the reference optical path lens cell 13. Further, the reference optical path lens cell 13 is fitted and fixed to the first lens barrel 14. The reference mirror 7 is fixed to the first lens barrel 14.

  The position of the reference optical path lens cell 13 is fixed. Further, the reference optical path lens cell 13 is rotated and adjusted if necessary, and fixed to the first lens barrel 14 with a set screw 16. Thereby, the distance between the reference optical path lens 12 and the reference mirror 7 is determined.

  The first lens barrel 14 and the second lens barrel 18 are fixed by being incorporated in a telescope type or a fitting type. A pin 17 is driven into the first lens barrel 14 to function as a guide. When the pin 17 moves along the groove 19 of the second lens barrel 18, the first lens barrel 14 is moved to the second lens barrel 14. 18 can be displaced without rotating in the optical axis direction. Therefore, the screws 20 can be fixed at an accurate position where necessary interference fringes can be obtained.

  It is also possible to form a plurality of grooves 19 on the periphery of the second lens barrel 18 so that the joint with the first lens barrel 14 can be made more rigid.

  The focus adjustment of the interference fringes is performed by moving the reference barrel unit 6 in the optical axis direction.

  As shown in detail in FIG. 3, a compensation element (dispersion compensation plate) 11 such as a glass plate, a reference optical path lens 10, and a reference mirror 7 are fixed in advance and integrated with a first lens barrel 14, and the second Since the first lens barrel 14 is attached to the lens barrel 18, the entire reference lens barrel unit 6 can be detachably attached to the interferometer.

  As shown in FIG. 4, preferably, the main optical axis of the reference mirror 7 is inclined several degrees. In order to make it easy to see, the tilt angle is shown by a dotted line.

  In the reference barrel unit 6, the first barrel 14 in which the reference optical path lens 10, the reference mirror 7, and the compensation element 11 are integrated is moved along the groove (guide) 19 of the second barrel 18, and the first barrel 14 is moved. The second lens barrels 14 and 18 can be fixed after adjusting their relative positions.

  By adopting a form other than the groove 19, a rail is installed, and the reference barrel unit 6 in which the reference optical path lens 10, the reference mirror 7, and the compensation element 11 are integrally provided is detachable along the rail. Good.

  Further, in the reference barrel unit 6, the reference (reflection) mirror 7 can be exchanged by using a plurality of mirrors having different reflectivities.

  As shown in FIG. 5, the reference barrel unit 6 is preliminarily adjusted to be unitized. In particular, the optical axes of the reference mirror 7, the reference optical path lens 10, and the dispersion compensation plate 11 (compensation element) are detected by the detector 21 when the optical axis is fixed to the first lens barrel 14 in advance, and are accurately matched. . Therefore, when assembling and adjusting the work of the interferometer, the work of aligning the optical axis of the reference light path can be omitted by simply attaching the first lens barrel 14 to the second lens barrel 18 and improving the work efficiency. Can be made.

  As shown in FIGS. 6 to 7, as the reference mirror 7, a wedge-shaped mirror may be provided inside the reference barrel unit 6 instead of the reflection mirror, or may be attached to the outside of the reference barrel unit 6. Good. Like the above, the wedge-shaped portion of the wedge-shaped mirror is inclined several degrees, for example, about 5 degrees. Similarly to the above, when assembling and adjusting the work of the interferometer, it is possible to omit the work of matching the optical axis of the reference optical path by simply attaching the first lens barrel 14 to the second lens barrel 18, thereby improving the work efficiency. Can be improved.

Claims (5)

  A reference mirror characterized in that the first lens barrel and the second lens barrel are assembled so that the reference optical path lens, the reference mirror, and the compensating element are all fixed in advance to the first lens barrel. Tube unit.   2. The reference lens barrel unit according to claim 1, wherein the reference mirror is disposed at an angle of several degrees with respect to the optical axis of the reference lens barrel unit.   The reference lens barrel unit according to claim 1, wherein the first lens barrel to which the reference optical path lens, the reference mirror, and the compensation element are integrally fixed has a guide, and the guide is attached to the second lens barrel. A reference barrel unit that moves along the formed groove so that a relative position between the first barrel and the second barrel can be adjusted.   4. The reference barrel unit according to claim 1, wherein the reference mirror can be replaced with a mirror having a different reflectance.   5. An interferometer, wherein the reference barrel unit according to claim 1 is detachably mounted.

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