JP2004102117A - Dust-proofing device of optical system for interferometer and interferometer system provided with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent dust etc., from adhering to optical parts, such as collimator lenses, by arranging light transmission plates for dust proofing between a plane reference plate and the collimator lenses so as to intersect obliquely with the axial direction of parallel luminous fluxes. <P>SOLUTION: A first luminous flux exit/imaging optical system 3 is dust-proofed and hermetically closed from the ambient space by a casing 30 having an aperture for light emission existing in front of the collimator lens 34 and the light transmission plate 36 for dust-proofing arranged to intersect obliquely with the optical axis L so as to close the aperture. In a similar embodiment, a second luminous flux exit/imaging optical system 4 is dust-proofed and hermetically closed from the ambient space by the casing 40 and the light transmission plate 46 for dust-proofing. Also, a reflection mirror 6 and its moving mechanism are dust-proofed and hermetically closed from the ambient space by the casing 60 and the light transmission plate 61 for dust-proofing, respectively. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a dustproof device of an optical system for an interferometer for preventing dust and the like from adhering to optical components such as a lens and a mirror constituting an optical system in an interferometer device, and a dustproof device of such type. The present invention relates to an interferometer device provided.
[0002]
[Prior art]
Conventionally, a light source unit that outputs light such as laser light used for light wave interference, a collimator lens that converts the light output from the light source unit into a parallel light beam, and a reflected light beam and a transmitted light beam that output the parallel light beam output from the collimator lens There is known an interferometer device including a flat or spherical reference plate which is divided into two. In such an interferometer device, in order to prevent dust and the like from adhering to the surface of optical components such as the collimator lens and the reflecting mirror that guides light from the light source unit to the collimator lens, these optical components are used. It is necessary to keep the configured optical system dust-tight with respect to the surrounding space.
[0003]
Conventionally, an optical system having a light source unit and a collimator lens is surrounded by a housing having an opening serving as a path for light output from the optical system, and the opening is closed by the flat or spherical reference plate. (See, for example, Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent No. 225612 (FIG. 1)
[0005]
[Problems to be solved by the invention]
In the case of the above-described dustproof structure, the reference plate serves as a dustproof window, but such a reference plate may be removed from the interferometer device for periodic maintenance or the like. At that time, there is a possibility that dust or the like may adhere to the surface of the optical component in the optical system.
[0006]
The present invention has been made in view of such circumstances, and even when the flat reference plate is removed from the interferometer device for periodic maintenance or the like, dust adheres to the surface of an optical component such as a collimator lens. An object of the present invention is to provide a dustproof device of an optical system for an interferometer which can be prevented, and an interferometer device provided with such a dustproof device.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, a dustproof device for an optical system for an interferometer according to the present invention includes a light source unit, a collimator lens that converts light from the light source unit into a parallel light beam, and a reflected light beam that reflects the parallel light beam from the collimator lens. And a plane reference plate having a reference plane for dividing the transmitted light beam into light beams, wherein the light source unit and the collimator lens are provided at a position between the plane reference plate and the collimator lens. The parallel optical system is provided with a dust-proof light transmitting plate that allows the parallel light beam to pass therethrough while sealing the optical system having the dust-proof seal against the space on the plane reference plate side. It is characterized by being arranged obliquely.
[0008]
Further, an interferometer device of the present invention is provided with a dustproof device for an optical system for an interferometer having the above characteristics.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
<Overview of interferometer device>
FIG. 1 is a diagram showing an interferometer apparatus provided with a dustproof device for an optical system for an interferometer according to an embodiment of the present invention. In addition, in order to make the description easy to understand, in FIG. 1, the distance between the optical components and the size of each of them are appropriately changed and shown.
An interferometer apparatus 1 shown in FIG. 1 is a pickup lens for an optical disk for recording / reproducing a signal on / from various optical disks such as a CD (compact disk), a DVD (digital versatile disk), and an LD (laser disk). A first light beam emitting / imaging device installed on the lower surface side of the optical surface plate 2 for inspection, particularly for inspection of a compatible pickup lens used in a CD / DVD compatible player device. The optical system includes an optical system 3, a second light beam emission / imaging optical system 4, and an interference optical system 5 installed on the upper surface of the optical surface plate 2.
[0011]
The first light beam emitting / imaging optical system 3 includes a light source unit 31 having a built-in laser light source that outputs a monochromatic laser beam having the same wavelength as a monochromatic laser beam for DVD recording / reproducing (for example, having a wavelength of 650 nm), a diverging lens 32, A semi-transparent mirror 33, a collimator lens 34, and an imaging CCD 35 are provided. The laser light emitted from the light source unit 31 is parallel to a first monochromatic light beam via a diverging lens 32, a semi-transparent mirror 33, and a collimator lens 34. And outputs the light to the outside of the first light beam emission / imaging optical system 3 (to the right in the figure).
[0012]
The second light beam emitting / imaging optical system 4 includes a light source unit 41 having a built-in laser light source that outputs a monochromatic laser beam having the same wavelength as a monochromatic laser beam (for example, having a wavelength of 780 nm) for CD recording / reproducing, a diverging lens 42, A semi-transparent mirror 43, a collimator lens 44, and a CCD 45 for imaging are provided. The laser beam emitted from the light source unit 41 passes through the diverging lens 42, the semi-transparent mirror 43, and the collimator lens 44 and is parallel to a second monochromatic light beam. And outputs the light toward the outside (upper side in the figure) of the second light beam emission / imaging optical system 4.
[0013]
On the right side of the first light beam emission / imaging optical system 3, there is disposed a reflecting mirror 6 that reflects the first monochromatic light beam output from the first light beam emission / imaging optical system 3 upward at a right angle. I have. The reflecting mirror 6 is moved by a mirror holding and moving mechanism (not shown) at a first position where the optical path of the first monochromatic light beam and the optical path of the second monochromatic light beam intersect, and at a first position outside the optical path of the second monochromatic light beam. 2 is movably held between the first position and the second position, and when the first monochromatic light beam is output by the holding / moving mechanism, the first monochromatic light beam is disposed at the first position and the second monochromatic light beam is output. In such a case, it is configured to be moved to the second position.
[0014]
By providing the first light beam emitting / imaging optical system 3, the second light beam emitting / imaging optical system 4, and the reflecting mirror 6, the multiple light beam interferometer apparatus 1 can be used as a single-color laser for DVD recording / reproducing. A first monochromatic luminous flux having the same wavelength as the light and a second monochromatic luminous flux having the same wavelength as the monochromatic laser light for CD recording / reproducing are selectively switched as necessary to the lower end of the interference optical system 5. It is possible to output the light toward a certain light beam introduction opening.
[0015]
On the other hand, the interference optical system 5 includes a flat reference plate 52 having a reference surface 51 and a lens mounting table 53 on which the pickup lens 7 is mounted. The flat reference plate 52 and the lens mounting table 53 are optically fixed. Each of the boards 2 is independently supported so that the inclination of its axis can be adjusted.
[0016]
Further, the interference optical system 5 includes a spherical reflector 54 supported by the five-axis adjustment stage 8. The spherical reflector 54 includes a reflective reference spherical surface 56 held by a lens barrel 55 and a lens barrel 55. And a press ring 57 of the reflection-type reference spherical surface 56 attached thereto. Further, on an optical path between the pickup lens 7 and the reflective reference spherical surface 56, a correction plate 58 for compensating optical characteristics of a protective layer formed for protecting a signal recording surface of the optical disk is provided. Are held and arranged in a correction plate case 9 attached to the camera.
[0017]
<Outline of dustproof device>
The above-described first light beam emission / imaging optical system 3 includes a housing 30 having a light emission opening positioned in front of the collimator lens 34, and a dustproof light transmitting plate arranged to cover the opening. 36 seals the surrounding space from dust. The dustproof light transmitting plate 36 is formed of, for example, general optical glass, and is disposed so that its surface is inclined (obliquely) with respect to a surface orthogonal to the optical axis L. I have.
[0018]
On the other hand, the above-described second light beam emission / imaging optical system 4 includes a housing 40 having an opening for light emission located in front of the collimator lens 44, and dustproof light arranged to cover the opening. As with the first light beam emission / imaging optical system 3, the surrounding space is dustproof and sealed by the transmission plate 46. The dustproof light transmitting plate 46 is formed of the same member as the dustproof light transmitting plate 36, and is arranged so that its surface is inclined with respect to a surface orthogonal to the optical axis L.
[0019]
In addition, the above-described reflecting mirror 6 and its moving mechanism include a housing 60 having an opening for light emission facing the flat reference plate 52, and a light-transmitting plate 61 for dustproof disposed to cover this opening. As a result, similarly to the first and second light beam emitting / imaging optical systems 3 and 4, the surrounding space is dust-proof and sealed. The dustproof light transmitting plate 61 is also formed of the same member as the dustproof light transmitting plates 36 and 46, and is arranged so that its surface is inclined with respect to a surface orthogonal to the optical axis L.
[0020]
As described above, in the present embodiment, since the first and second light beam emission / imaging optical systems 3 and 4 and the reflecting mirror 6 are both dust-proof and sealed in the surrounding space, the flat reference plate 52 is maintained. Thus, even if it is detached from the interferometer device 1, it is possible to prevent dust and the like from adhering to optical components such as the collimator lenses 34 and 44 and the reflecting mirror 6. Furthermore, since each of the dust-proof light transmitting plates 36, 46, 61 is disposed so as to be inclined with respect to a plane orthogonal to the optical axis L, the light reflected by these dust-proof light transmitting plates 36, 46, 61 is reflected. Are directed away from the direction of the optical axis L. The front and back surfaces of the dustproof light transmitting plates 36, 46, 61 and another surface orthogonal to the optical axis L (for example, the reference surface 51). ) Does not occur, and light reflected from the front and back surfaces of the dustproof light transmitting plates 36, 46, 61 can be prevented from becoming noise of light wave interference. Note that the inclination direction of the dustproof light transmitting plate 61 is set to be different from the inclination directions of the dustproof light transmitting plates 36 and 46 so as not to adversely affect the light wave interference.
[0021]
The embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment, and various aspects can be changed.
For example, in the above-described embodiment, the first light beam emission / imaging optical system 3, the second light beam emission / imaging optical system 4, and the reflecting mirror 6 are each sealed in a dust-proof manner by a separate housing and a dust-proof light transmitting plate. However, it is also possible to seal them with one common housing and dustproof light transmitting plate.
[0022]
In the above-described embodiment, for example, it is also possible to seal only the first and second light beam emitting / imaging optical systems 3 and 4 without dust-proof sealing of the reflecting mirror 6.
[0023]
Furthermore, in the above embodiment, the present invention is applied to an interferometer apparatus that switches monochromatic light beams having different wavelengths and outputs the same by switching two light source units. The present invention can be applied to an interferometer device.
[0024]
Further, in the above embodiment, the present invention is applied to an interferometer device having a Fizeau-type interferometer optical system, but other interferometer devices, for example, interferometers such as a Michelson type or a Twyman-Green type It is also applicable to devices.
[0025]
【The invention's effect】
As described above in detail, according to the dustproof device for the optical system for an interferometer of the present invention, the optical system including the light source unit and the collimator lens is provided at a position between the plane reference plate and the collimator lens. A dust-proof light-transmitting plate that allows the parallel light flux from the collimator lens to pass through is arranged obliquely to the optical axis while sealing the dust-proof seal against the space on the side of the plane reference plate. To play.
In other words, since the optical system is dust-proof and sealed against the surrounding space, even when the flat reference plate is removed from the interferometer device for maintenance or the like, dust and the like are prevented from adhering to the optical components such as the collimator lens. It is possible to do.
[0026]
Further, since the dust-proof light transmitting plate is disposed obliquely to the optical axis, light reflected by the dust-proof light transmitting plate is directed to a direction different from the optical axis direction. However, light wave interference does not occur between the front and back surfaces of the dust-proof light transmitting plate and other surfaces orthogonal to the optical axis, and the reflected light from the front and back surfaces of the dust-proof light transmitting plate causes noise of the light wave interference. Can be prevented.
[0027]
Further, according to the interferometer device of the present invention, since the dustproof device of the optical system for an interferometer of the present invention is provided, dust and the like hardly adhere to optical components in the optical system. For this reason, the possibility that dust or the like adversely affects the light wave interference is reduced, and an environment in which highly accurate measurement can be performed can be maintained.
[Brief description of the drawings]
FIG. 1 is a diagram of an interferometer device including a dustproof device for an optical system for an interferometer according to an embodiment of the present invention.
DESCRIPTION OF SYMBOLS 1 Interferometer apparatus 2 Optical base 3 First light beam emission / imaging optical system 4 Second light beam emission / imaging optical system 5 Interference optical system 6 Reflecting mirror 7 Pickup lens 8 5-axis adjustment stage 9 Correction plate case 11 Position adjustment Stages 30, 40, 60 Cases 31, 41 Light source 32, 42 Diverging lenses 33, 43 Semi-transparent mirrors 34, 44 Collimator lenses 35, 45 CCD
36, 46, 61 Dust-proof light transmitting plate 51 Reference surface 52 Flat reference plate 53 Lens mounting table 54 Spherical reflector 55 Lens barrel 56 Reflective reference spherical surface 57 Press ring 58 Correction plate L Optical axis of interferometer device

Claims (2)

A light source unit, a collimator lens that converts light from the light source unit into a parallel light beam, and a plane reference plate having a reference surface that divides the parallel light beam from the collimator lens into a reflected light beam and a transmitted light beam. In the interferometer device
At a position between the plane reference plate and the collimator lens, the optical system including the light source unit and the collimator lens is dust-tightly sealed with respect to the space on the plane reference plate side, while the parallel light flux is A dust-proof device for an optical system for an interferometer, comprising: a light-transmitting plate for transmitting dust; and the light-transmitting plate for dust is disposed obliquely to an axial direction of the parallel light flux. An interferometer apparatus comprising the dustproof device for an optical system for an interferometer according to claim 1.

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