JP2008116900A - Interference objective lens, and interference microscope apparatus with interference objective lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive interference objective lens capable of easily obtaining not only an interference image but also a bright-field image of good contrast, and to provide an interference microscope apparatus with the interference objective lens. <P>SOLUTION: This interference microscope apparatus comprises: the interference objective lens 1 arranged above a sample 11 and having an objective lens 10, a first beam splitter 12 and a reference surface 13; an observation optical system 2 arranged above the interference objective lens 1; and an illumination optical system 3 having a light source 14 such as a halogen lamp for emitting light from a visible range to an infrared range. The interference microscope apparatus can easily obtain not only the interference image but also the bright-field image of good contrast. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an interference objective lens that measures and observes a three-dimensional shape of a sample, and an interference microscope apparatus including the interference objective lens.

  In general, a microscopic interference measurement method (interference microscope apparatus) is known as a method for measuring a three-dimensional shape of a fine sample with high accuracy. For example, Patent Document 1 discloses a micro interference measurement method in which light emitted from a light source is guided to a sample via an interference objective lens. This microscopic interference measurement method captures an interference image in which reflected light reflected from a sample (hereinafter referred to as measurement light) and reflected light reflected from a reference surface provided in the interference objective lens (hereinafter referred to as reference light) are interfered. , Obtain interference images.

  Examples of the interference objective lens include a Michelson type interference objective lens and a Mirau type interference objective lens. In both the Michelson interference objective lens and the Mirau interference objective lens, a reference optical path is formed by a beam splitter provided inside the interference objective lens. In the reference optical path, a reference mirror surface is provided at a position conjugate with the object side focal position of the interference objective lens.

  A light source in the microscopic interference measurement method is a halogen lamp, a mercury lamp, or the like, and emits white visible light having a wide wavelength range. The light emitted from this light source is mixed with light of various wavelengths. Thus, since the light source emits white light, that is, light having a short coherent length, an interference image is generated when the optical path difference between the measurement light and the reference light is zero. The distance at which the interference image is generated (coherence distance) is very narrow with an optical path difference of several micrometers or less. The coherence distance becomes narrower as the wavelength width of the light source, that is, the bandwidth is wider. Further, the interference intensity becomes strongest when the optical path difference between the measurement light and the reference light is zero.

  The microscopic interference measurement method measures the three-dimensional shape of a sample using such properties.

That is, each time the interference objective lens is scanned in the optical axis direction (hereinafter referred to as the Z direction) by the drive unit, the imaging unit (hereinafter referred to as the image sensor) sequentially acquires sample interference images. For all the pixels of the interference image captured by the image sensor, the control unit obtains the position in the optical axis direction when the interference intensity is maximum. Thereby, the three-dimensional shape of the sample is obtained.
US Pat. No. 5,133,601

  However, since the reference light is superimposed over the entire field of view in the microscope image obtained by the conventional apparatus using the above-described method, the image has poor contrast such as flare. In particular, when the contrast of a sample is low, such as a mirror surface of glass, for example, there is a possibility that the contrast of the microscopic image is lowered so that it cannot be observed depending on the sample.

  Thus, when an observer or a measurement person observes or measures a sample having a low contrast, it is not easy to find an object to be observed or a measurement object, and it is not easy to focus. Therefore, it becomes difficult for an observer or a measurer to find a coherent region having only a few micrometers.

  In such a case, the observer or the measurer can switch the objective lens to a normal bright field objective lens to obtain an approximate registration of the observation target and the focus position. However, these operations are time-consuming, and it is expensive to install a bright-field objective lens.

  The present invention has been made in view of these circumstances, and an inexpensive interference objective lens capable of easily obtaining not only an interference image but also a bright-field image with good contrast, and an interference microscope including the interference objective lens An object is to provide an apparatus.

  In order to achieve the object, the present invention is arranged between an objective lens for irradiating a sample with light, the sample and the objective lens, and transmitting the one light by dividing the light, while the other An interference objective lens comprising: a light dividing member that reflects the light; and a reference surface that is disposed on an optical path divided by the light dividing member and is irradiated with the light reflected from the light dividing member. The light dividing member divides only the light having a desired wavelength at a desired ratio, and transmits and reflects the light, or the reference surface transmits only the light having a desired wavelength. An interference objective lens characterized by reflecting is provided.

  In order to achieve the object, the present invention is disposed between a light source that emits light to a sample, an objective lens that irradiates the sample with the light emitted from the light source, and between the objective lens and the sample. A first light splitting member that transmits one of the lights by splitting the light and reflects the other light; and an optical path split by the first light splitting member; An interference objective lens having a reference surface irradiated with the other light reflected from the light splitting member, and forming an image of the light reflected from the sample and the light reflected from the reference surface. And an observation optical system for observing an interference image, wherein the first light splitting member splits only the light in a desired wavelength range at a desired ratio or the reference. Face Reflects only the light of the wavelength range, the observation optical system provides an interference microscope apparatus characterized by observing the interference image by imaging the light of the wavelength range desired.

  In order to achieve the object of the present invention, a light source that emits light from a visible region to an infrared region on a sample, an objective lens that irradiates the sample with the light emitted from the light source, the objective lens, A light splitting member disposed between the samples and transmitting one of the light by splitting the light and reflecting the other light; and an optical path split by the light splitting member; An interference objective lens having a reference surface irradiated by the other light reflected from the dividing member; and interference formed by imaging the light reflected from the sample and the light reflected from the reference surface. An interference optical device for observing an image, wherein the light splitting member splits only the light in the infrared region at a desired ratio, or the reference surface is the infrared light The interference optical apparatus is characterized in that only the light is reflected and the observation optical system forms the light in the visible region or the light in the infrared region to observe the interference image. .

  In order to achieve the object, the present invention provides a light source that emits light to a sample, an objective lens that irradiates the sample with light emitted from the light source, and is disposed between the objective lens and the sample to divide the light. The first light splitting member that transmits one light and reflects the other light and the other light beam that is disposed on the optical path split by the first light splitting member and reflected from the first light splitting member A first objective optical system comprising: an interference objective lens having a reference surface irradiated with light; and an observation optical system for observing an interference image by forming an image of light reflected from the interfering sample and light reflected from the reference surface. An interference microscope apparatus comprising: a second microscope that also serves as an objective lens together with the first microscope and is different from the first microscope, and the first light splitting member comprises: Only light in the desired wavelength range is desired Or the reference surface reflects only light in a desired wavelength region, and the observation optical system forms an image of light in the desired wavelength region and observes an interference image. A microscope apparatus is provided.

  In order to achieve the object, the present invention provides a light source that emits light to a sample, an objective lens that irradiates the sample with light emitted from the light source, and is disposed between the objective lens and the sample to divide the light. The first light splitting member that transmits one light and reflects the other light and the other light beam that is disposed on the optical path split by the first light splitting member and reflected from the first light splitting member A first objective optical system comprising: an interference objective lens having a reference surface irradiated with light; and an observation optical system for observing an interference image by forming an image of light reflected from the interfering sample and light reflected from the reference surface. And a sensor optical system that also serves as an objective lens together with the first microscope, and the first light splitting member only desires light in a desired wavelength range. Divide at the ratio The reference surface, reflects only light in a wavelength range desired, the observation optical system provides an interference microscope apparatus characterized by observing an interference image by imaging the light in the wavelength range desired.

  According to the present invention, it is possible to provide an inexpensive interference objective lens that can easily obtain not only an interference image but also a bright-field image with good contrast, and an interference microscope apparatus including the interference objective lens.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram of an interference microscope apparatus according to the first embodiment of the present invention.

  The interference microscope apparatus according to this embodiment includes an interference objective lens 1 disposed above a sample 11, an observation optical system 2 disposed above the interference objective lens 1, an interference objective lens 1, and an observation optical system 2. It is comprised from the illumination optical system 3 arrange | positioned between. The sample 11 is placed on a stage (not shown).

  In the illumination optical system 3, a light source 14 that emits light from the visible range to the infrared range, for example, a halogen lamp or the like, and the light emitted from the light source 14 is condensed, projected, and projected from a plurality of lenses. An optical system 15 and a half mirror 16 that reflects light projected by the projection optical system 15 downward (on the interference objective lens 1 side) are sequentially arranged. The projection optical system 15 projects the image of the light source 14 onto the pupil position of the interference objective lens 1. The half mirror 16 is disposed on the optical axis 22. The half mirror 16 transmits reflected light reflected from the sample 11 and a reference surface 13 described later toward the observation optical system 2.

  The interference objective lens 1 is disposed below the half mirror 16, and collects the light and irradiates the sample 11 with the light emitted from the light source 14, and is disposed between the objective lens 10 and the sample 11. A first beam splitter 12 (for example, a dichroic prism or a dichroic mirror) that is a first light splitting member that transmits one of the light transmitted through the objective lens 10 and reflects the other, and a first beam splitter 12 A reference surface 13 irradiated with the reflected light is sequentially arranged. The objective lens 10, the first beam splitter 12, and the reference surface 13 are disposed on the optical axis 22 of the interference objective lens 1 and constitute a Mirau interference optical system. The reference surface 13 is disposed at a position optically conjugate with the object side focal position of the objective lens 10 via the first beam splitter 12. The surface of the reference surface 13 (the surface facing the first beam splitter 12) is a mirror surface. The reference plane 13 is disposed on the optical path divided by the first beam splitter 12.

  In the observation optical system 2, an imaging lens 17 that forms an image of light reflected from the sample 11 and the reference surface 13 and transmitted through the interference objective lens 1 and the half mirror 16, and a focal position of the imaging lens 17, are arranged. For example, an image pickup unit 18 such as a CCD camera that is an image pickup unit that picks up the light imaged by the image forming lens 17 and the light passing through the image forming lens 17 are disposed between the image forming lens 17 and the image pickup device 18. A second beam splitter (for example, a dichroic prism or a dichroic mirror) 19 that is a second light splitting member that transmits or reflects light according to a wavelength range, and between the second beam splitter 19 and the image sensor 18. When visually observing the light reflected by the second beam splitter 19 and the bandpass filter 21 that is arranged and has different transmittance depending on the wavelength range of the transmitted light An eyepiece lens 20 which is an observation unit used, but are sequentially arranged. The imaging lens 17, the image sensor 18, the second beam splitter 19, the band pass filter 21, and the eyepiece lens 20 are disposed on the optical axis 22. Note that the eyepiece 20 is disposed on at least one optical path divided by the second beam splitter 19. Further, since the band-pass filter 21 has a different transmittance according to the wavelength range of the transmitted light (because the transmitted light is limited), the image sensor 18 captures an interference image corresponding to the wavelength range.

  FIG. 2 shows the reflection transmittance characteristics of the first beam splitter 12 (relationship between the reflectance and transmittance of the first beam splitter 12 and the wavelength of light transmitted through the first beam splitter 12). FIG. 3 shows the reflection transmittance characteristic of the second beam splitter 19. As shown in FIGS. 2 and 3, the first beam splitter 12 and the second beam splitter 19 have different reflectivities and transmissivities depending on the wavelength range of the transmitted light. As described above, the first beam splitter 12 and the second beam splitter 19 divide the light at a desired ratio according to the wavelength range of the desired light, and transmit or reflect the light. FIG. 4 shows the transmittance characteristics of the bandpass filter 21. As shown in FIG. 4, the band-pass filter 21 has a different transmittance depending on the wavelength range of the transmitted light.

Next, an operation method of the interference microscope apparatus in the present embodiment will be described.
The light emitted from the light source 14 is condensed and projected by the projection optical system 15 and reflected downward by the half mirror 16. At this time, the reflected one reflected light passes through the objective lens 10 and the first beam splitter 12 and irradiates the sample 11. The other reflected light passes through the objective lens 10 and is then reflected by the first beam splitter 12 to irradiate the reference surface 13.

  Specifically, the sample 11 has a light amount of about 100% of light having a wavelength of 780 nm or less (hereinafter referred to as visible light) and light having a wavelength of 780 nm or more (hereinafter referred to as “visible light”) due to the reflection transmittance characteristics of the first beam splitter 12. (Referred to as infrared light). Further, the reference surface 13 is irradiated with a light amount of about 50% of infrared light due to the reflection transmittance characteristic of the first beam splitter 12. The reference surface 13 is not irradiated with visible light due to the reflection transmittance characteristic of the first beam splitter 12. The reference surface 13 reflects the infrared light reflected by the first beam splitter.

  The reflected light reflected from the sample 11 passes through the first beam splitter 12 again based on the reflection transmittance characteristic of the first beam splitter 12 and passes through the objective lens 10. The reflected light reflected from the reference surface 13 is reflected again by the first beam splitter 12 based on the reflection transmittance characteristic of the first beam splitter 12 described above, and passes through the objective lens 10. At this time, the reflected light reflected from the reference surface 13 is only infrared light. Therefore, the reflected light reflected from the sample 11 causes light interference only in this wavelength region. Therefore, the transmitted light that passes through the objective lens 10 includes light in a wavelength region having such interference information (infrared light) and light in a wavelength region having no interference information (visible light).

  The transmitted light that has passed through the objective lens 10 passes through the half mirror 16 and is imaged by the imaging lens 17. At that time, the second beam splitter 19 transmits infrared light and reflects visible light based on the reflection transmittance characteristic shown in FIG.

  In the infrared light transmitted through the second beam splitter 19, only light in a wavelength region centered on a desired wavelength of 900 nm is further transmitted through the bandpass filter 21 by the bandpass filter 21 having the transmittance shown in FIG. The infrared light transmitted through the bandpass filter 21 is imaged by the image sensor 18. The infrared light transmitted through the bandpass filter 21 has interference information. Therefore, the image sensor 18 has interference information, and an interference image corresponding to the wavelength region is captured. The center wavelength of the bandpass filter 21 determines the period of the interferogram, and the bandwidth determines the coherence distance. The characteristics of the bandpass filter 21 can be set arbitrarily (desired) in a desired wavelength region of infrared light, for example.

  Visible light reflected by the second beam splitter 19 enters the eyepiece lens 20, and an enlarged image of the sample 11 is visually observed by the eyepiece lens 20. This visible light does not contain interference information as described above. That is, since the reflected light (reference light) reflected from the reference surface 13 is not superimposed on the visually observed image, a clear image with good contrast (hereinafter, an image on which the reference light is not superimposed is referred to as a bright field image). Can be obtained.

  Next, an operation method when performing three-dimensional shape measurement on the sample 11 will be described.

  While performing visual observation with the eyepiece 20, the focus is roughly adjusted to a desired position of the sample 11 (first focus adjustment). Next, an image picked up by the image pickup device 18 is referred to, and focus adjustment (second focus adjustment) is performed more finely than the above operation so that interference fringes are generated. The focus is roughly adjusted during the first focus adjustment. Therefore, there is an interference area in the vicinity of the position where the first focusing is performed. Therefore, interference fringes can be easily found during the second focusing. When the interference fringes are found, the interference objective lens 1 is scanned along the optical axis 22 by a scanning mechanism (not shown) provided in the interference objective lens 1, and interference images are sequentially acquired. At that time, the scanning position where the interference intensity is maximum is determined for each pixel of the image, and the three-dimensional shape of the sample 11 is measured.

  As described above, according to the present embodiment, even when the interference objective lens 1 is used, it is possible to obtain a bright-field image with good contrast without flare caused by the reference light during visual observation. Therefore, this embodiment can easily find the observation position and the focus position even when observing a sample with low contrast. In addition, this embodiment can quickly find a region where an interference fringe of an interference image is generated.

  Moreover, since this embodiment can simultaneously acquire a bright-field image obtained with a normal microscope and an interference image obtained by the image sensor 18 during visual observation, an operation such as switching of an objective lens is not required as in a conventional apparatus. . Thereby, this embodiment can be constructed at low cost while improving operability.

  Next, a first modification of the present embodiment will be described with reference to FIG.

  In the first embodiment described above, the Mirau-type interference objective lens is used as the interference objective lens, but the present invention is not limited to this. For example, a Michelson interference objective lens may be used, and this modification will be described.

  FIG. 5 is a diagram showing a schematic configuration of a Michelson interference objective lens used in this modification.

  As shown in FIG. 5, the interference objective lens 101 in this modification example includes the objective lens 10, a first beam splitter 112 that transmits one of the light transmitted through the objective lens 10, and reflects the other, and a first beam. And a reference surface 113 that is irradiated with light reflected by the splitter 112. The objective lens 10 and the first beam splitter 112 are disposed on the optical axis 22 of the interference objective lens 101. The reference surface 113 is disposed on the reflected light path 114 of the first beam splitter 112. Thus, the objective lens 10, the first beam splitter 112, and the reference surface 113 constitute a Michelson interference optical system. The reference surface 113 is disposed at a position optically conjugate with the object-side focal position of the objective lens 10 via the first beam splitter 112. A surface of the reference surface 113 (a surface facing the first beam splitter 112) is a mirror surface. The reflection transmittance characteristics of the first beam splitter 112 are the same as those in FIG. The configurations of the observation optical system 2 other than the interference objective lens 101 and the illumination optical system 3 are the same as those in the first embodiment described above, and thus detailed description thereof is omitted.

  Since the operation method of the interference microscope apparatus and the operation method when performing the three-dimensional shape measurement on the sample 11 in the present modification are the same as those in the first embodiment described above, the description thereof is omitted here.

  Therefore, the same effects as those of the first embodiment described above can be obtained even if a Michael type interference optical system is used instead of the Mirau type interference optical system as in this modification.

  Next, a second modification of the present embodiment will be described with reference to FIGS.

  In the first embodiment described above, light in a wavelength region having interference information and light in a wavelength region having no interference information are separated by infrared light and visible light, but the present invention is not limited to this. For example, only visible light may be used, and the wavelength range of visible light may be separated into a wavelength range having interference information and a wavelength range not having interference information, and this modification will be described.

  FIG. 6 shows the reflection transmittance characteristics of the first beam splitter when separating into a wavelength region having interference information and a wavelength region not having interference information with a wavelength of 500 nm, which is a wavelength region of visible light, as a boundary. Yes. FIG. 7 shows the reflection transmittance characteristics of the second beam splitter in the case where the wavelength is 500 nm, which is the wavelength range of visible light, and is separated into a wavelength region having interference information and a wavelength region not having interference information. Yes. FIG. 8 shows the transmittance characteristics of the bandpass filter.

  6 and 7, the configuration of this modification is such that the reflection transmittance characteristics of the first beam splitter 12 and the second beam splitter 19 and the transmittance characteristics of the bandpass filter 21 as shown in FIG. Unlike the first embodiment described above, the other configurations are the same as those of the first embodiment described above, and are therefore omitted. As shown in FIG. 8, the bandpass filter 21 in the present modification transmits visible light in a wavelength region centered on a wavelength of 600 nm.

  This modification is different from the first embodiment described above only in the boundary wavelength (500 nm) between the wavelength region having interference information and the wavelength region not having interference information. Therefore, as in the first embodiment described above, in the operation method of this modification, a bright-field image with good contrast that does not include interference information when visually observed through the eyepiece 20, and an interference image by the image sensor 18. Can be acquired at the same time. In addition, since visible light contains only the component of a wavelength range of 500 nm or less, this bright field image turns into an image with a strong blue taste. Further, the sample position and focus adjustment in this modification can be performed in the same manner as in the first embodiment.

  As described above, in this modification, since the wavelength range of visible light is separated into two with the wavelength of 500 nm as a boundary, the amount of light in the wavelength range having interference information can be increased according to the application. Thereby, this modification can improve S / N of an interference image. Further, in this modification, the output of the light source can be reduced, and an inexpensive imaging element that does not have a high S / N can be used, and the apparatus can be configured at a low cost.

  In this modification, an interference image is acquired in a wavelength region of 500 nm or more with a boundary of 500 nm, and a bright field image is acquired in a wavelength region of 500 nm or less. However, the present invention is not limited to this, and an interference image may be acquired in a wavelength region of 500 nm or less, and a bright field image may be acquired in a wavelength region of 500 nm or more. As described above, in this modification, only the light in the desired wavelength region can be divided at the desired ratio in the first beam splitter 12 and the second beam splitter 19. Specifically, in this modification, the first beam splitter 12 and the second beam splitter 19 reflect or transmit light according to a desired wavelength range, and an interference range (a wavelength range having interference information), What is necessary is just to isolate | separate a non-interference area (wavelength area which does not have interference information).

  Next, a third modification of the present embodiment will be described with reference to FIGS.

  In the first embodiment described above, an interference image is captured by the image sensor 18, and a bright field image is visually observed by the eyepiece 20. However, the present invention is not limited to this. For example, a bright field image may be picked up by the image pickup device 18 and the interference image may be visually observed by the eyepiece lens 20, and this modification will be described.

  FIG. 9 shows the configuration of the second beam splitter in this modification. 10 and 11 show the reflection transmittance characteristics of the second beam splitter in this modification.

  In this modification, the second beam splitter 19 of the first embodiment described above is replaced with two second beam splitters 120 and 121 as shown in FIG. One of the second beam splitters 120 and 121 is arranged on the optical axis 22 by a switching mechanism (not shown). As described above, the second beam splitters 120 and 121 are disposed on the optical axis 22 so as to be switchable. FIG. 10 shows the reflection transmittance characteristic of the second beam splitter 120. FIG. 11 shows the reflection transmittance characteristic of the second beam splitter 121. As shown in FIGS. 10 and 11, the reflection transmittance characteristics of the second beam splitters 120 and 121 have characteristics in which the relationship between reflection and transmission is opposite.

  When the second beam splitter 120 is disposed on the optical axis 22, the long-wavelength light having interference information is transmitted through the second beam splitter 120 and then the imaging optical path, as in the first embodiment. It is guided to the image sensor 18 via 122. As a result, an interference image is captured by the image sensor 18. Further, short-wavelength light having no interference information (light having a shorter wavelength than that of long-wavelength light) is reflected by the second beam splitter 120 and then passes through the visual observation optical path 123 to the eyepiece lens 20. Led. Thereby, the bright field image is visually observed by the eyepiece 20.

  When the second beam splitter 121 is disposed on the optical axis 22, contrary to the case where the second beam splitter 120 is disposed on the optical axis 22, a bright field image is captured by the imaging element 18, The interference image can be visually observed by the eyepiece 20.

  As described above, in this modification, the light guided to the image sensor 18 via the imaging optical path 122 and the light guided to the eyepiece 20 via the visual observation optical path 123 can be interchanged. As a result, the present modified example can take a bright field image with the image sensor 18 and visually observe the interference image with the eyepiece 20, and thus can be applied to various observation methods.

  In the present embodiment, two types of second beam splitters 120 and 121 having different reflection transmittance characteristics are used, but it is not necessary to limit to this number. Further, although switching is possible using a switching mechanism (not shown), the second beam splitters 120 and 121 mounted on a rotary type or, for example, a filter slider may be exchanged by being inserted into and removed from the optical axis 22. The configuration of the switching mechanism (not shown) is not limited as long as the second beam splitters 120 and 121 can be arranged on the optical axis 22 in this way.

  Next, a fourth modification of the present embodiment will be described with reference to FIG.

  In the first embodiment described above, as shown in FIG. 2, the first beam splitter 12 has a reflection transmittance of about 50% in the infrared light band, but the present invention is not limited to this. For example, a spectral ratio such as a transmittance of about 30% and a reflectance of about 70% in the infrared light band as shown in FIG. Thus, a beam splitter having an appropriate (desired) spectral ratio according to the reflectance of the sample 11 may be used. Thereby, this modification can acquire the same effect as a 1st embodiment mentioned above. Moreover, this modification can respond widely to the sample 11 when observing and measuring.

  Next, a second embodiment will be described with reference to FIG.

The same parts as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 13 is a schematic diagram of an interference microscope apparatus according to the second embodiment.
The present embodiment is different from the first embodiment described above in the illumination optical system and the observation optical system. Since the configuration of the interference objective lens 1 of the present embodiment is the same as that of the first embodiment described above, detailed description thereof is omitted.

  The illumination optical system 200 of the present embodiment emits a visible light source 201 such as a white LED light source that emits visible light, an infrared light source 202 such as an infrared LED light source that emits infrared light, and a visible light source 201. The dichroic mirror 203 that transmits visible light and reflects the infrared light emitted from the infrared light source 202, and the visible light transmitted through the dichroic mirror 203 or the infrared light reflected by the dichroic mirror 203 are collected. A projection optical system 15 for projecting and a half mirror 16 are arranged.

  The observation optical system 2 of the present embodiment is not provided with the band pass filter 21. The other configuration of the observation optical system 2 is the same as that of the first embodiment described above.

The light path until the infrared light emitted from the infrared light source 202 enters the dichroic mirror 203 is a light emission optical path 205, and the light path until the visible light emitted from the visible light source 201 enters the dichroic mirror 203 is a light emission optical path 204. Let the optical axis of the illumination optical system 200 be the illumination optical axis 206.
The dichroic mirror 203, the projection optical system 15, and the half mirror 16 are arranged on the illumination optical axis 206. Similar to the first embodiment described above, the objective lens 10, the first beam splitter 12, the reference surface 13, the half mirror 16, the imaging lens 17, the imaging element 18, the second beam splitter 19, and the eyepiece 20 Are arranged on the optical axis 22 of the interference objective lens 1.

  Next, an operation method of the interference microscope apparatus in the present embodiment will be described.

  Visible light emitted from the visible light source 201 passes through the dichroic mirror 203, passes through the projection optical system 15 on the illumination optical axis 206, and then is reflected downward (to the interference objective lens 1 side) by the half mirror 16. Infrared light emitted from the infrared light source 202 is reflected by the dichroic mirror 203, passes through the projection optical system 15 on the illumination optical axis 206, and then is reflected downward (to the interference objective lens 1 side) by the half mirror 16. The Visible light and infrared light reflected downward by the half mirror 16 enter the interference objective lens 1.

  Visible light incident on the interference objective lens 1 passes through the objective lens 10 and the first beam splitter 12 and irradiates the sample 11. The infrared light incident on the interference objective lens 1 passes through the objective lens 10, is reflected by the first beam splitter, and irradiates the reference surface 13.

  Specifically, the sample 11 has a light amount of about 100% of light (visible light) having a wavelength of 780 nm or less and light (infrared light) having a wavelength of 780 nm or more due to the reflection transmittance characteristic of the first beam splitter 12. Approximately 50% of the light is irradiated. Further, the reference surface 13 is irradiated with a light amount of about 50% of infrared light due to the reflection transmittance characteristic of the first beam splitter 12. The reference surface 13 is not irradiated with light of a visible light component due to the reflection transmittance characteristic of the first beam splitter 12.

  The visible light reflected from the sample 11 passes through the first beam splitter 12 again based on the reflection transmittance characteristic of the first beam splitter 12 and passes through the objective lens 10. The reflected light reflected from the reference surface 13 is reflected again by the first beam splitter 12 based on the reflection transmittance characteristic of the first beam splitter 12 described above, and passes through the objective lens 10. At this time, the reflected light reflected from the reference surface 13 is only infrared light. Therefore, the visible light reflected from the sample 11 causes light interference only in this wavelength region. Therefore, the transmitted light that passes through the objective lens 10 includes light in a wavelength region having such interference information (infrared light) and light in a wavelength region having no interference information (visible light).

  The transmitted light that has passed through the objective lens 10 passes through the half mirror 16 and is imaged by the imaging lens 17. At that time, the second beam splitter 19 transmits infrared light and reflects visible light based on the reflection transmittance characteristic shown in FIG.

  The infrared light transmitted through the second beam splitter 19 has interference information. Therefore, an interference image having interference information is captured on the image sensor 18.

  Visible light reflected by the second beam splitter 19 enters the eyepiece lens 20, and an enlarged image of the sample 11 is visually observed by the eyepiece lens 20. This visible light does not contain interference information as described above. That is, since the reflected light (reference light) reflected from the reference surface 13 is not superimposed on the visually observed image, a clear bright field image with good contrast can be obtained.

  Next, an operation method when performing three-dimensional shape measurement on the sample 11 will be described.

  While performing visual observation with the eyepiece 20, the focus is roughly adjusted to a desired position of the sample 11 (first focus adjustment). At that time, the brightness of the bright field image can be adjusted by adjusting the amount of visible light emitted from the visible light source 201. Next, an image picked up by the image pickup device 18 is referred to, and focus adjustment (second focus adjustment) is performed more finely than the above operation so that interference fringes are generated. The focus is roughly adjusted during the first focus adjustment. Therefore, there is an interference area in the vicinity of the position where the first focusing is performed. Therefore, interference fringes can be easily found during the second focusing. At that time, the brightness of the interference fringes can be adjusted by adjusting the amount of infrared light emitted from the infrared light source 202. When the interference fringes are found, the interference objective lens 1 is scanned along the optical axis 22 by a scanning mechanism (not shown) provided in the interference objective lens 1, and interference images are sequentially acquired. At that time, the scanning position where the interference intensity is maximum is determined for each pixel of the image, and the three-dimensional shape of the sample 11 is measured.

  As described above, this embodiment can obtain a bright-field image with good contrast without flare caused by reference light even when the interference objective lens 1 is used, as in the first embodiment described above. . Therefore, this embodiment can easily find the observation position and the focus position even when observing a sample with low contrast. In addition, this embodiment can quickly find a region where an interference fringe of an interference image is generated.

  Moreover, since this embodiment can simultaneously acquire a bright-field image obtained with a normal microscope and an interference image obtained by the image sensor 18 during visual observation, an operation such as switching of an objective lens is not required as in a conventional apparatus. . Thereby, this embodiment can be constructed at low cost while improving operability.

  In the present embodiment, the bandpass filter 21 used in the first embodiment is not provided. This embodiment is provided with a visible light source 201 and an infrared light source 202 which are independent light sources. Therefore, if the spectral characteristics of infrared light emitted from the infrared light source 202 are known, stable interference infrared light can be obtained without using the bandpass filter 21.

  Furthermore, in the present embodiment, the brightness of the interference image captured by the image sensor 18 is the brightness of the infrared light emitted from the infrared light source 202, and the brightness of the bright field image observed by the eyepiece 20 is It can be adjusted by adjusting the amount of visible light emitted from the visible light source 201. Since the infrared light source 202 and the visible light source 201 are independent, they can be individually adjusted. Therefore, the brightness of the interference image and the brightness of the bright field image can be adjusted independently. Adjustment of the brightness of the interference image is important in terms of measurement accuracy. Independently adjusting the brightness of the interference image without being affected by the brightness adjustment of the bright field image is advantageous in terms of measurement accuracy.

  If at least one of the interference image and the bright field image is unnecessary, the light source corresponding to the unnecessary image may be turned off, and unnecessary light need not be emitted.

  Next, a third embodiment will be described with reference to FIGS.

The same parts as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 14 is a schematic diagram of an interference microscope apparatus according to the third embodiment.
This embodiment is different from the above-described first embodiment in the interference objective lens and the observation optical system.

  In the interference objective lens 249 of the present embodiment, the spectral characteristics of the first beam splitter 252 are different from those of the first beam splitter 12 of the first embodiment described above. Since the configuration of the interference objective lens 249 other than the first beam splitter 252 is the same as that of the first embodiment described above, description thereof is omitted.

  FIG. 15 shows the reflection transmittance characteristic of the first beam splitter 252. The first beam splitter 252 separates the wavelength range with a boundary near the wavelength of 550 nm, which is the center wavelength of the green wavelength range. Specifically, the first beam splitter 252 transmits light having a wavelength of 550 nm or less, divides light having a wavelength of 550 nm or more at a desired ratio described later, and transmits or reflects this light.

  In the observation optical system 250, an imaging lens 17 and a color imaging element 251 which is an imaging unit arranged at an imaging position of the imaging lens 17 are arranged. FIG. 16 shows spectral sensitivity characteristics for each wavelength of each color. As the color image sensor 251, a three-plate CCD camera is used as shown in FIG. As shown in FIG. 17, the color image sensor 251 is provided with a color separation prism 256 and image sensors 253, 254, and 255 for imaging each color (R, G, B) separated by the color separation prism 256. ing.

  Next, an operation method of the interference microscope apparatus in the present embodiment will be described.

  The light emitted from the light source 14 is condensed and projected by the projection optical system 15 and reflected downward (on the interference objective lens 249 side) by the half mirror 16. One of the reflected lights is transmitted through the objective lens 10 and the first beam splitter 252 to irradiate the sample 11. The other reflected light passes through the objective lens 10 and is then reflected by the first beam splitter 252 to irradiate the reference surface 13.

  Specifically, the sample 11 has a light amount of about 100% of light having a wavelength of 550 nm or less (hereinafter referred to as short wavelength light) and light having a wavelength of 550 nm or more (hereinafter referred to as short wavelength light) due to the reflection transmittance characteristics of the first beam splitter 252. In the following, approximately 50% of the light is irradiated. Further, the reference surface 13 is irradiated with a light amount of about 50% of the long wavelength light due to the reflection transmittance characteristic of the first beam splitter 252. The reference surface 13 is not irradiated with light having a short wavelength light component due to the reflection transmittance characteristic of the first beam splitter 252.

  The reflected light reflected from the sample 11 passes through the first beam splitter 252 again and passes through the objective lens 10 based on the reflection transmittance characteristics of the first beam splitter 252 described above. The reflected light reflected from the reference surface 13 is reflected again by the first beam splitter 252 based on the reflection transmittance characteristic of the first beam splitter 252 described above, and passes through the objective lens 10. At this time, the reflected light reflected from the reference surface 13 is only long-wavelength light. Therefore, the reflected light reflected from the sample 11 causes light interference only in this wavelength region. Therefore, the transmitted light transmitted through the objective lens 10 includes light in a wavelength region having such interference information (long wavelength light) and light in a wavelength region having no interference information (short wavelength light). .

  The transmitted light that has passed through the objective lens 10 passes through the half mirror 16 and is imaged on the imaging surface of the color imaging element 251 by the imaging lens 17. The formed transmitted light is separated for each of R, G, and B by the color separation prism 256. The red component (R) is received by the image sensor 253, the green component (G) is received by the image sensor 254, and the blue component (B) is received by the image sensor 255.

  Long wavelength light having interference information is received by the image sensor 253, and short wavelength light having no interference information is received by the image sensor 255. When the light received by the image sensor 253 (red component) is imaged, an interference image is obtained, and when the light received by the image sensor 255 (blue component) is imaged, a bright field image (non-interference image) is obtained. It is done. Since the reference light is not superimposed on the bright field image, a clear image with good contrast can be obtained.

  Next, an operation method when performing three-dimensional shape measurement on the sample 11 will be described.

  The bright field image picked up by the image pickup device 255 is referred to, and the focus is roughly adjusted to the desired position of the sample 11 (first focus adjustment). Next, the image picked up by the image pickup device 253 is referred to, and focus adjustment (second focus adjustment) is performed more finely than the above operation so that interference fringes are generated. The focus is roughly adjusted during the first focus adjustment. Therefore, there is an interference area in the vicinity of the position where the first focusing is performed. Therefore, interference fringes can be easily found during the second focusing. When the interference fringes are found, the interference objective lens 249 is scanned along the optical axis 22 by a scanning mechanism (not shown) provided in the interference objective lens 249, and interference images are sequentially acquired. At that time, the scanning position where the interference intensity is maximum is determined for each pixel of the image, and the three-dimensional shape of the sample 11 is measured.

  As described above, this embodiment can obtain an image with good contrast without flare caused by the reference light, as in the first embodiment.

  Further, in the present embodiment, it is possible to switch between the interference image and the bright field image by selecting a color component from the images obtained by the color image sensor 251 and displaying the image. Therefore, in this embodiment, a general microscope optical system having a color imaging function is combined with an interference objective lens capable of selecting and interfering with the wavelength which is a characteristic part of this embodiment, so that the system configuration is general-purpose. The microscope can be used as it is. Thus, since a general-purpose microscope is added to the base, the apparatus price is low.

  In the present embodiment, a three-plate CCD, so-called three-CCD, is used as the color image sensor, but the present invention is not limited to this. For example, a single-plate CCD image sensor using a color filter may be used.

  In the present embodiment, the reflection transmittance characteristic of the first beam splitter 252 is set to about 50% as shown in FIG. 15, but the present invention is not limited to this. The present embodiment may be divided at a desired ratio such as a transmittance of about 30% and a reflectance of about 70%.

  Next, a fourth embodiment will be described with reference to FIGS.

The same parts as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 18 is a schematic diagram of an interference microscope apparatus according to the fourth embodiment.
The present embodiment is different from the first embodiment described above in the observation optical system. Since the configuration other than the observation optical system of the present embodiment is the same as that of the first embodiment described above, detailed description thereof is omitted.

  In the observation optical system 300 of this embodiment, an imaging lens 17 that forms an image of light reflected from the sample 11 and the reference surface 13 and transmitted through the interference objective lens 1 and the half mirror 16, and a focal position of the imaging lens 17. The image pickup device 18 such as a CCD camera that picks up the light imaged by the imaging lens 17 and the filter switching mechanism 301 arranged between the imaging lens 17 and the image pickup device 18 are sequentially arranged. ing.

  The filter switching mechanism 301 has two types of bandpass filters 302 and 303 having different transmittance characteristics. The filter switching mechanism 301 rotates about the rotation center axis 304 to place one of the bandpass filters 302 and 303 on the optical axis 22. As described above, the band pass filters 302 and 303 are arranged on the optical axis 22 so as to be switchable. FIG. 19 shows the transmittance characteristics of the bandpass filter 302. FIG. 20 shows the transmittance characteristics of the bandpass filter 303. As shown in FIGS. 19 and 20, the band-pass filters 302 and 303 have different transmittances according to the wavelength of the transmitted light. As shown in FIG. 19, the band pass filter 302 in the present embodiment transmits light in a wavelength region centered on a wavelength of 900 nm. As shown in FIG. 20, the bandpass filter 303 in the present modification transmits light in a wavelength region centered on a wavelength of 550 nm.

  Next, an operation method of the interference microscope apparatus in the present embodiment will be described.

  The light emitted from the light source 14 is condensed and projected by the projection optical system 15 and reflected downward (to the interference objective lens 1 side) by the half mirror 16. At this time, the reflected one reflected light passes through the objective lens 10 and the first beam splitter 12 and irradiates the sample 11. The other reflected light passes through the objective lens 10 and is then reflected by the first beam splitter 12 to irradiate the reference surface 13.

  Specifically, the sample 11 has a light amount of about 100% of light having a wavelength of 780 nm or less (hereinafter referred to as visible light) and light having a wavelength of 780 nm or more (hereinafter referred to as “visible light”) due to the reflection transmittance characteristics of the first beam splitter 12. (Referred to as infrared light). Further, the reference surface 13 is irradiated with a light amount of about 50% of infrared light due to the reflection transmittance characteristic of the first beam splitter 12. The reference surface 13 is not irradiated with light of a visible light component due to the reflection transmittance characteristic of the first beam splitter 12.

  The reflected light reflected from the sample 11 passes through the first beam splitter 12 again based on the reflection transmittance characteristic of the first beam splitter 12 and passes through the objective lens 10. The reflected light reflected from the reference surface 13 is reflected again by the first beam splitter 12 based on the reflection transmittance characteristic of the first beam splitter 12 described above, and passes through the objective lens 10. At this time, the reflected light reflected from the reference surface 13 is only infrared light. Therefore, the reflected light reflected from the sample 11 causes light interference only in this wavelength region. Therefore, the transmitted light that passes through the objective lens 10 includes light in a wavelength region having such interference information (infrared light) and light in a wavelength region having no interference information (visible light).

  The transmitted light that has passed through the objective lens 10 passes through the half mirror 16 and is imaged by the imaging lens 17. Further, the transmitted light is transmitted through the band-pass filter 302 or the band-pass filter 303 disposed on the optical axis 22 by the filter switching mechanism 301. At that time, if the band-pass filter 302 is arranged on the optical axis 22 by the filter switching mechanism 301, the image sensor 18 is centered on the wavelength of 900 nm based on the transmittance characteristics of the band-pass filter 302 shown in FIG. An interference image by infrared light is captured. Also, if the band-pass filter 303 is arranged on the optical axis 22 by the filter switching mechanism 301, the imaging device can detect visible light centered on a wavelength of 550 nm based on the transmittance characteristics of the band-pass filter 303 shown in FIG. Take a bright field image by.

  As described above, in the present embodiment, by switching the band-pass filter disposed on the optical axis 22 by the filter switching mechanism 301, it is possible to switch and capture the interference image or the bright field image.

  Next, an operation method when performing three-dimensional shape measurement on the sample 11 will be described.

  A band pass filter 303 is arranged on the optical axis 22 by the filter switching mechanism 301. Next, the focus is roughly adjusted to a desired position of the sample 11 (first focus adjustment). Next, the filter switching mechanism 301 rotates and the band pass filter 302 is disposed on the optical axis 22. At that time, an image picked up by the image pickup device 18 is referred to, and focus adjustment (second focus adjustment) is performed more finely than the above operation so that interference fringes are generated. The focus is roughly adjusted during the first focus adjustment. Therefore, there is an interference area in the vicinity of the position where the first focusing is performed. Therefore, interference fringes can be easily found during the second focusing. When the interference fringes are found, the interference objective lens 1 is scanned along the optical axis 22 by a scanning mechanism (not shown) provided in the interference objective lens 1, and interference images are sequentially acquired. At that time, the scanning position where the interference intensity is maximum is determined for each pixel of the image, and the three-dimensional shape of the sample 11 is measured.

  As described above, this embodiment can obtain the same effects as those of the first embodiment described above. Furthermore, since this embodiment does not require a dedicated observation optical path to obtain a bright field image, it can be configured at low cost.

  In this embodiment, two types of band-pass filters 302 and 303 having different transmittance characteristics are used, but it is not necessary to limit to this number. The filter switching mechanism 301 is a rotary type. However, for example, a bandpass filter mounted on a filter slider may be inserted and removed from the optical axis 22 for replacement. If the bandpass filter can be arranged on the optical axis 22 in this way, the configuration of the filter switching mechanism 301 is not limited.

  Next, a fifth embodiment will be described with reference to FIGS.

The same parts as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 21 is a schematic diagram of an interference objective lens of an interference microscope apparatus according to the fifth embodiment.
This embodiment is different from the first embodiment described above in the interference objective lens. Since the observation optical system 2 and the illumination optical system 3 are the same as those in the first embodiment described above, they are not shown, and detailed descriptions thereof are also omitted. In the first to fourth embodiments described above, the wavelength range in which interference is caused and the wavelength range in which interference is not caused are separated by the reflection transmittance characteristic of the first beam splitter 12 provided in the interference objective lens. However, in this embodiment, the wavelength range that causes interference and the wavelength range that does not cause interference are separated by the reflectance characteristics of the reference surface.

  The interference objective lens 401 of this embodiment includes an objective lens 10, a first beam splitter 402 that is a wide-band beam splitter that divides all light having wavelengths from the visible range to the infrared range, and a first beam splitter. The reference surface 403 is irradiated with light reflected by the light 402. Thus, the interference objective lens 401 is a Michelson interference objective lens. The reference surface 403 has reflectance characteristics as shown in FIG. The reference surface 403 has a characteristic of reflecting only infrared light and transmitting or absorbing visible light.

  A light source 14 (not shown) emits light having a wavelength from the visible range to the infrared range. This light is condensed and projected by the projection optical system 15 and reflected downward by the half mirror 16. One of the reflected reflected light passes through the objective lens 10 and the first beam splitter 402 and irradiates the sample 11. The other reflected light passes through the objective lens 10, is reflected by the first beam splitter 402, and irradiates the reference surface 403.

  Reflected light that passes through the first beam splitter 402 (one reflected light, light that irradiates the sample 11) and reflected light that is reflected by the first beam splitter 402 (the other reflected light, light that irradiates the reference surface 403) ) Includes visible light and infrared light.

  The reflected light reflected from the sample 11 passes through the first beam splitter 402 again based on the reflection transmittance characteristic of the first beam splitter 402 described above, passes through the objective lens 10 and the half mirror 16, and passes through the observation optical system 2. Is incident on. The reflected light reflected from the reference surface 403 is reflected again by the first beam splitter 402 based on the reflection transmittance characteristic of the first beam splitter 402 described above, passes through the objective lens 10 and the half mirror 16, and is observed optically. The light enters the system 2. At this time, reflection is performed on the reference surface 403 based on the reflectance characteristics of the reference surface shown in FIG. Thereby, the reflected light reflected from the reference surface 403 is only infrared light due to the reflectance characteristics of the reference surface 403 shown in FIG. Therefore, the reflected light reflected from the sample 11 causes light interference only in this wavelength region. Therefore, the transmitted light that passes through the objective lens 10 includes light in a wavelength region having such interference information (infrared light) and light in a wavelength region having no interference information (visible light).

  Since the operation method of the observation optical system 2 in this embodiment and the operation method when performing three-dimensional shape measurement on the sample 11 are the same as those in the first embodiment described above, a description thereof will be omitted.

  As described above, according to the present embodiment, when visual observation is performed, visible light that does not include reference light can be observed, so that a bright-field image with good contrast can be observed. Further, when an interference image is picked up by the image pickup device 18, only the infrared light component needs to be picked up. Thus, this embodiment can easily obtain a bright-field image and an interference image.

  In addition, although this embodiment demonstrated using the Michelson type | mold interference objective lens, it is not necessary to limit to this. Even in the case of a Mirau interference objective lens, the same effect as in the present embodiment can be obtained as long as the reference surface has a characteristic of reflecting only in a desired wavelength region.

  Next, a sixth embodiment will be described with reference to FIG.

The same parts as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 23 is a schematic diagram of an interference microscope apparatus according to the sixth embodiment.
In the present embodiment, an index projection optical system 500 is added to the configuration of the first embodiment described above. The index projection optical system 500 is disposed between the observation optical system 2 and the illumination optical system 3.

  The index projection optical system 500 includes a light source 501 that is, for example, an LED light source that emits green light (center wavelength 550 nm), a condensing lens 502 that condenses light emitted from the light source 501, and a condensing lens 502. A projection lens 505 for projecting the condensed light, a half mirror 503 for reflecting the light projected by the projection lens 505 downward (to the interference objective lens 1 side), the object side focal position of the interference objective lens 1 and the optical The indicator patterns 504 arranged in a conjugate position are sequentially arranged. The half mirror 503 is disposed on the optical axis 22. The light source 501 projects the index pattern 504 on the object side focal position of the interference objective lens 1. The index pattern 504 is a geometric pattern such as a grid pattern, a crosshair pattern, or a circular pattern. The index pattern 504 is formed on the transparent substrate. The index pattern 504 may be a simple hole (opening) such as a circle or a rectangle instead of on the transparent substrate.

  The operation method of the interference microscope apparatus in this embodiment (operation for obtaining an interference image and a bright-field image) is the same as that in the first embodiment described above, and is therefore omitted.

  Next, the operation of the index projection optical system 500 will be described. The light emitted from the light source 501 is collected by the condenser lens 502 and then passes through the index pattern 504. The light transmitted through the index pattern 504 is projected by the projection lens 505 and then reflected downward by the half mirror 503. The reflected light reflected downward passes through the half mirror 16 and then enters the interference objective lens 1.

  The light incident on the interference objective lens 1 is green component light that is visible light. This light is not reflected by the first beam splitter 12, and all the light passes through the first beam splitter 12 and irradiates the sample 11. Therefore, this light does not irradiate the reference surface 13. At that time, a projected image 506 of the index pattern 504 is projected onto the focal position of the interference objective lens 1. The reflected light reflected from the sample 11 passes through the first beam splitter 12 again and passes through the objective lens 10. The light transmitted through the objective lens 10 passes through the half mirror 16 and the half mirror 503 and enters the observation optical system 2.

  The light incident on the observation optical system 2 is imaged by the imaging lens 17. The imaged light is visible light having a green component as described above. Therefore, all of this light is reflected by the second beam splitter 19. The reflected light reflected by the second beam splitter 19 enters the eyepiece lens 20. Further, reflected light (visible light) from the sample 11 by the illumination optical system 3 enters the eyepiece 20. In other words, the green index light from the index projection optical system 500 and the visible light from the illumination optical system 3 are superimposed on the eyepiece 20.

  When the sample 11 coincides with the focal position of the interference objective lens 1 (in a focused state), the clear vision image of the sample 11 and the green index pattern image are observed simultaneously by visual observation with the eyepiece 20. When the sample 11 does not coincide with the focal position of the interference objective lens 1 (defocused state), a blurred image of the index pattern is observed by visual observation with the eyepiece 20.

  As described above, in the present embodiment, it is understood that the position of the sample 11 is the focus position of the bright field image by adjusting the position of the sample 11 so that the index pattern image can be clearly observed. As described above, in the present embodiment, when the sample 11 is difficult to be contrasted, such as glass or transparent resin, or when the sample 11 has deposits such as dust and the contrast becomes low, focusing becomes easy. Operability can be improved. Further, since the projected image 506 of the index pattern 504 is visible light, it does not enter the image sensor 18 that captures an interference image. Therefore, this embodiment can suppress the influence with respect to the three-dimensional shape measurement by an interference image.

Next, a seventh embodiment will be described with reference to FIG. 24 and FIG.
The same parts as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 24 is a schematic diagram of an interference microscope apparatus according to the seventh embodiment. FIG. 25 is a schematic view of a confocal laser scanning microscope.

  The interference microscope apparatus according to this embodiment includes an illumination optical system 600 that emits light to a sample 11, an interference objective lens 1 that irradiates the sample 11 with light emitted from the illumination optical system 600, the sample 11 that interferes, and a reference. A first microscope including an interference objective lens 1, a dichroic mirror 603, and an observation optical system 605 for observing an interference image by imaging the light reflected from the surface 13 via the half mirror 16; A confocal laser scanning microscope 610 that is a second microscope that also shares (shares) the objective lens 10 with the microscope.

In addition, the interference microscope apparatus in this embodiment should just have a confocal microscope, and if it is a confocal microscope, it is not necessary to limit to the confocal laser scanning microscope 610. FIG.
Further, the configuration of the interference objective lens 1 of the present embodiment is the same as that of the first embodiment described above, and thus detailed description of the interference objective lens 1 is omitted. Note that the objective lens 10 (interference objective lens 1) of this embodiment is also used as the first microscope and the confocal laser scanning microscope 610 as described above.

  The interference microscope apparatus also includes a half mirror 16 that reflects light emitted from the illumination optical system 600 and guides the light to the interference objective lens 1 and a dichroic mirror 603 that is a first light splitting member. The dichroic mirror 603 has a reflection transmittance characteristic that reflects the light 604 emitted from the light source 14 and transmits the laser light 612 emitted from the laser light source 611.

  In the illumination optical system 600, as in the first embodiment, the light source 14 and the first projection optical system 15 are sequentially arranged. The first projection optical system 15 is composed of a plurality of lenses as in the first embodiment, and projects the image of the light source 14 onto the pupil position of the interference objective lens 1. Between the first projection optical system 15, a filter switching mechanism 601 and a reflection mirror 602 are sequentially arranged.

  The filter switching mechanism 601 has two types of filters having different transmittance characteristics (a high-pass filter 601a that is a first transmission filter and a low-pass filter 601b that is a second transmission filter). Similar to the filter switching mechanism 301 described above, the filter switching mechanism 601 rotates about the rotation center axis 601c, thereby placing either the high-pass filter 601a or the low-pass filter 601b on the optical axis 22. As described above, the high-pass filter 601a and the low-pass filter 601b are arranged on the optical axis 22 so as to be exchangeable. The high-pass filter 601a has a desired threshold value, and transmits light in a wavelength region equal to or greater than the threshold value from the light emitted from the light source 14. Specifically, the high-pass filter 601a has a characteristic of transmitting, for example, only infrared light (long-wavelength light having interference information) and blocking or reflecting light other than infrared light. The low-pass filter 601b has a desired threshold value that is substantially the same as that of the high-pass filter 601a, and transmits light having a wavelength range equal to or less than the threshold value from the light emitted from the light source 14. Specifically, the low-pass filter 601b, for example, has a characteristic of transmitting only visible light (light shorter than long-wavelength light (short-wavelength light having no interference information)) and blocking or reflecting light other than visible light, for example. Have

  The reflection mirror 602 reflects the light transmitted through the high pass filter 601a or the low pass filter 601b toward the first projection optical system 15. The first projection optical system 15 projects the light reflected from the reflection mirror 602 toward the half mirror 16, and the half mirror 16 reflects the light projected by the first projection optical system 15 toward the dichroic mirror 603. . The dichroic mirror 603 reflects the light reflected from the half mirror 16 toward the interference objective lens 1. The dichroic mirror 603 reflects the light reflected from the sample 11 and the reference surface 13 and transmitted through the interference objective lens 1 toward the half mirror 16 as in the first embodiment. The dichroic mirror 603 transmits a laser beam 612 having a wavelength of 408 nm emitted from a laser light source 611 described later, and transmits the laser beam 612 reflected from the sample 11 without being divided. As described above, the dichroic mirror 603 transmits light without dividing the wavelength of light emitted from the laser light source 611 disposed in the confocal laser scanning microscope 610 as the second microscope. The half mirror 16 transmits the light reflected from the dichroic mirror 603.

  The observation optical system 605 is disposed on the transmission optical path of the half mirror 16. The observation optical system 605 is disposed at the focal position of the first imaging lens 606 for imaging the light that has passed through the half mirror 16 (enlarged image by the interference objective lens 1), and the first imaging lens 606. A color imaging element 607 that is an imaging unit that images the light imaged by the first imaging lens 606 is sequentially arranged.

  The configuration of the color image sensor 607 is substantially the same as the configuration of the color image sensor 251 (see FIG. 17) in the third embodiment described above. Therefore, the spectral sensitivity characteristics for each wavelength of each color in the color image sensor 607 are the same as those in FIG. The color image sensor 607 images light that has passed through the high-pass filter 601a and light that has passed through the low-pass filter 601b. Specifically, the color image sensor 607 captures infrared light when the high-pass filter 601a is disposed on the optical axis. The filter 601b captures visible light arranged on the optical axis.

  The confocal laser scanning microscope 610 is disposed above the dichroic mirror 603 (on the transmission optical path). As shown in FIG. 25, the confocal laser scanning microscope 610 transmits a laser light source 611 that emits laser light (visible light) 612 having a wavelength of 408 nm, for example, and a laser light 612 emitted from the laser light source 611. In addition, a second beam splitter 613 that reflects a laser beam 612 reflected from the sample 11 to be described later, and a laser beam 612 that has passed through the second beam splitter 613 by rotating is two-dimensional with respect to the surface of the sample 11. Two-dimensional scanning mechanisms 614 that scan in the direction are sequentially arranged.

Note that the laser light source 611 is not necessarily limited to emitting laser light 612 having a wavelength of 408 nm, for example, and may emit light in a wavelength region that transmits the first beam splitter 12.
The second beam splitter 613 reflects or transmits the laser beam 612 according to the polarization characteristic of the laser beam 612. The two-dimensional scanning mechanism 614 is disposed at a position conjugate with the pupil of the objective lens 10, and is, for example, a resonant scanner or a galvano scanner.

  In the confocal laser scanning microscope 610, a second projection optical system 615 is disposed on the optical path of the laser beam 612 scanned by the two-dimensional scanning mechanism 614. Similar to the first projection optical system 15, the second projection optical system 615 includes a plurality of lenses, and condenses and projects the laser light 612 scanned by the two-dimensional scanning mechanism 614. The second projection optical system 615 is disposed on the transmission optical path of the dichroic mirror 603 described above.

  In the confocal laser scanning microscope 610, the laser light 612 projected by the second projection optical system 615 passes through the dichroic mirror 603, enters the interference objective lens 1, and irradiates the sample 11. At that time, the first beam splitter 12 which is a light splitting member transmits the laser light 612 emitted from the laser light source 611. As described above, the confocal laser scanning microscope 610 is also used (shared) as the objective lens 10 (interference objective lens 1) together with the first microscope.

  The confocal laser scanning microscope 610 includes a second imaging lens 616, a pinhole 617, and a laser light receiving element 618 that is a laser light receiving unit on an optical path reflected by the second beam splitter 613. Are arranged sequentially. The second imaging lens 616 images the laser beam 612 reflected by the second beam splitter 613. The pinhole 617 is disposed at a position conjugate with the focal position of the objective lens 10, and is focused on the surface of the sample 11 by the objective lens 10, and only the laser beam 612 that is focused on the surface of the sample 11. Pass through. The laser beam 612 passes through the pinhole 617 when the sample 11 is disposed at the focus position, and is blocked by the pinhole 617 when the sample 11 is disposed at the defocus position. The laser light receiving element 618 receives the laser light 612 that has passed through the pinhole 617. For the laser light receiving element 618, for example, a photomultiplier tube or a photodiode is used.

Next, an operation method of the illumination optical system 600, the half mirror 16, the dichroic mirror 603, the interference objective lens 1, and the observation optical system 605 in the present embodiment will be described.
Light 604 emitted from the light source 14 is collected by the first projection optical system 15. The condensed light is transmitted through the high-pass filter 601 a disposed on the optical axis 22 by the filter switching mechanism 601. At that time, only the infrared light is transmitted by the high-pass filter 601a. The infrared light that has passed through the high-pass filter 601a is reflected toward the first projection optical system 15 by the reflection mirror 602, and is projected toward the half mirror 16 by the first projection optical system 15.

  The infrared light is reflected by the half mirror 16 and the dichroic mirror 603, enters the interference objective lens 1, and passes through the objective lens 10. Infrared light transmitted through the objective lens 10 is divided by the first beam splitter 12. One of the divided lights passes through the first beam splitter 12 and irradiates the sample 11. The other light is reflected by the first beam splitter 12 and irradiates the reference surface 13.

  Specifically, the sample 11 is irradiated with about 50% of light having a wavelength of 780 nm or more (hereinafter referred to as infrared light) due to the reflection transmittance characteristic of the first beam splitter 12. Further, the reference surface 13 is irradiated with a light amount of about 50% of infrared light due to the reflection transmittance characteristic of the first beam splitter 12. The reference surface 13 reflects the infrared light reflected by the first beam splitter.

  The reflected light reflected from the sample 11 passes through the first beam splitter 12 again based on the reflection transmittance characteristic of the first beam splitter 12 and passes through the objective lens 10. The reflected light reflected from the reference surface 13 is reflected again by the first beam splitter 12 based on the reflection transmittance characteristic of the first beam splitter 12 described above, and passes through the objective lens 10. Therefore, the reflected light reflected from the sample 11 causes light interference only in this wavelength region. The reflected light (infrared light) reflected from the reference surface 13 and the reflected light (infrared light) reflected from the sample 11 are combined. This combined light has interference information.

  The combined light passes through the objective lens 10, is reflected by the dichroic mirror 603, passes through the half mirror 16, and is imaged on the imaging surface of the color imaging element 607 by the first imaging lens 606. The imaged light is separated for each of R, G, and B in the color image sensor 607.

  The wavelength band of the imaged light is an infrared region. Therefore, the color image sensor 607 acquires only the information of the red component (R) when the light is separated. Thus, when the information of the red component (R) is imaged, an interference image is obtained (the color imaging element 607 captures an interference image having interference information).

  When the low-pass filter 601 b is disposed on the optical axis 22 by the filter switching mechanism 601, only visible light is incident on the interference objective lens 1. Visible light incident on the interference objective lens 1 passes through the objective lens 10 and the first beam splitter 12 and irradiates the sample 11.

  Specifically, the sample 11 is irradiated with a light amount of about 100% of light (visible light) having a wavelength of 780 nm or less due to the reflection transmittance characteristic of the first beam splitter 12.

  The visible light reflected from the sample 11 passes through the first beam splitter 12 again based on the reflection transmittance characteristic of the first beam splitter 12 and passes through the objective lens 10. The light that passes through the objective lens 10 has no interference information.

  The light that has passed through the objective lens 10 is reflected by the dichroic mirror 603, passes through the half mirror 16, is imaged on the imaging surface of the color imaging element 607 by the first imaging lens 606, and is imaged by the color imaging element 607. Is done.

  This light does not contain interference information as described above. Therefore, the reflected light (reference light) reflected from the reference surface 13 is not superimposed on this light. As a result, a clear image (bright field image) with good contrast is obtained. Note that a color bright-field image can be obtained by the color imaging element 607.

Next, a confocal laser scanning type operation method in this embodiment will be described.
The laser light 612 emitted from the laser light source 611 is transmitted through the second beam splitter 613, reflected by the two-dimensional scanning mechanism 614, and scanned (for example, raster scanning) in the two-dimensional direction with respect to the surface of the sample 11. . Since the two-dimensional scanning mechanism 614 scans the laser light 612, the emission (polarization) angle at which the two-dimensional scanning mechanism 614 emits the laser light 612 is determined based on the size of the field of view to be observed, the light projection magnification, and the like. .

  The scanned laser beam 612 passes through the second projection optical system 615 and the dichroic mirror 603 and enters the interference objective lens 1. Since the laser light 612 is visible light, it passes through the first beam splitter 12 and irradiates one point of the sample 11. At that time, since the two-dimensional scanning mechanism 614 emits the laser beam 612 within the above-described emission angle, one point irradiated with the sample 11 changes (scans) with time, and finally reaches the entire observation region. Scanned.

  The laser beam 612 that has scanned the sample 11 in this manner is reflected by the sample 11, passes through the interference objective lens 1 and the dichroic mirror 603, and enters the confocal laser scanning microscope 610. The laser beam 612 reflected by the sample 11 does not include interference information.

  The laser beam 612 incident on the confocal laser scanning microscope 610 passes through the second projection optical system 615, passes through the two-dimensional scanning mechanism 614, and enters the second beam splitter 613.

As described above, the laser beam 612 passes through exactly the same path as that incident on the sample 11 and enters the second beam splitter 613.
The laser beam 612 reflected by the second beam splitter 613 is guided to the second imaging lens 616. In addition, since the two-dimensional scanning mechanism 614 is disposed at a position conjugate with the pupil position of the objective lens 10, the laser light 612 is emitted from the second imaging lens 616 even when the two-dimensional scanning mechanism 614 scans off-axis. It doesn't move above.

  The laser beam 612 is focused in a dot shape by the second imaging lens 616 and passes through the pinhole 617. As described above, the pinhole 617 is disposed at a position conjugate with the imaging position of the laser beam 612 that has passed through the objective lens 10 (the focal position of the objective lens 10), and the laser beam that is focused on the surface of the sample 11 Pass only 612. As a result, only the laser beam 612 that is focused on the surface of the sample 11 by the objective lens 10, reflected from the surface of the sample 11, and passed through the pinhole 617 is received by the laser light receiving element 618. The laser beam 612 is received by the laser light receiving element 618 without being blocked by the pinhole 617 only when the sample 11 is imaged by the objective lens 10 (confocal effect).

  A control unit (not shown) forms a two-dimensional observation image (surface image of the sample 11) according to the emission angle of the two-dimensional scanning mechanism 614 using the light amount of the laser light 612 received by the laser light receiving element 618 as a luminance value. This observation image is displayed brightly only in the focused state. The control unit displays the observation image on a display unit such as a monitor (not shown). The resolution of the observation image displayed is higher than the resolution of the observation image displayed by a normal microscope.

  Thus, since the interference microscope apparatus of this embodiment can select a wavelength band (infrared region or visible region) by the filter switching mechanism 601, a bright field image with good contrast without flare can be easily and inexpensively. Interference images can be acquired.

  The interference microscope apparatus according to the present embodiment is a second microscope that combines the first microscope using the objective lens 10 (interference objective lens 1) and the objective lens 10 (interference objective lens 1) together with the first microscope. A confocal laser scanning microscope 610 is added. The laser light 612 emitted from the laser light source 611 of the confocal laser scanning microscope 610 does not include interference information. Therefore, the interference microscope apparatus of the present embodiment can obtain a bright-field image with good contrast as described above, and a clear observation image in which no interference fringes are generated by the confocal laser scanning microscope 610 together with the interference image.

  Moreover, since this embodiment does not require switching between the visible light source 201 and the infrared light source 202 as in the second embodiment described above, it is possible to prevent the output of the light source 14 from becoming unstable. Moreover, since the time for stabilizing the output of the light source 14 can be omitted in this embodiment, it is possible to acquire a bright field image and an interference image in a shorter time.

  In the present embodiment, a three-plate CCD, so-called three-CCD, is used as the color image sensor, but the present invention is not limited to this. For example, a single-plate CCD image sensor using a color filter may be used.

  In this embodiment, the confocal laser scanning microscope 610 is used. However, as described above, the confocal microscope need not be limited to this. For example, a confocal scanning microscope using a nipou disk or the like is used. Also good.

  In this embodiment, the filter switching mechanism 601 can be used for switching. However, the high-pass filter 601a and the low-pass filter 601b mounted on the rotary type or, for example, the filter slider are inserted and removed from the optical axis 22 for replacement. May be. The configuration of the filter switching mechanism 601 is not limited as long as the high-pass filter 601a and the low-pass filter 601b can be arranged on the optical axis 22 in this way. The high pass filter 601a and the low pass filter 601b may be switched manually. Thereby, it can switch easily.

  The high-pass filter 601a and the low-pass filter 601b are arranged in the illumination optical system 600, but may be arranged in the observation optical system 605.

  Moreover, it is not necessary to limit to the high-pass filter 601a and the low-pass filter 601b, for example, the band-pass filter and reflection type filter shown in FIG. 4 may be used. As described above, the configuration of the filter of the present embodiment is not limited as long as the wavelength band can be selected.

Next, a first modification of the present embodiment will be described with reference to FIG.
The same parts as those in the seventh embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 26 is a schematic diagram of an interference microscope apparatus in the present modification.

  The interference microscope apparatus of the present modification is different from the seventh embodiment described above in the illumination optical system and the observation optical system. Since the configurations of the interference objective lens 1, the half mirror 16, the dichroic mirror 603, and the confocal laser scanning microscope 610 of the present modification are the same as those in the seventh embodiment, detailed description thereof is omitted.

  In the illumination optical system 600 of this modification, the filter switching mechanism 601 is not disposed.

The observation optical system 650 of the present modified example has a first imaging lens 606 and a desired spectrum of light imaged by the first imaging lens 606 (light reflected from the sample 11 and the reference surface 12). A third beam splitter 653 that is a light splitting member that splits according to characteristics is disposed. Note that the third beam splitter 653 transmits one of the lights and reflects the other when dividing the light.
The observation optical system 650 is imaged by the first imaging lens 606 and a high-pass filter 601 a that transmits the light transmitted by the third beam splitter 653 on the transmission optical path of the third beam splitter 653. A first image sensor 651 that is an imaging unit that images light transmitted through the high-pass filter 601a is sequentially arranged.

  In addition, the observation optical system 650 is imaged by a first imaging lens 606 and a low-pass filter 601 b that transmits the light reflected by the third beam splitter 653 on the reflected light path of the third beam splitter 653. A second image sensor 652 for imaging the light transmitted through the low-pass filter 601b is sequentially arranged.

  The first image sensor 651 and the second image sensor 652 are arranged at the focal position of the first imaging lens 606, and are, for example, a CCD camera.

Next, operation methods of the illumination optical system 600, the half mirror 16, the dichroic mirror 603, the interference objective lens 1, and the observation optical system 650 in this modification will be described.
The light 604 emitted from the light source 14 enters the interference objective lens 1 and passes through the objective lens 10 as in the seventh embodiment described above. This light 604 has infrared light and visible light.

  In the light 604 that has passed through the objective lens 10, the infrared light is split by the first beam splitter 12. One of the divided infrared lights passes through the first beam splitter 12 and irradiates the sample 11. The other infrared light is reflected by the first beam splitter 12 and irradiates the reference surface 13.

  The reflected light reflected from the sample 11 and the reflected light reflected from the reference surface 13 are again returned to the first beam splitter 12 based on the reflection transmittance characteristic of the first beam splitter 12 as in the seventh embodiment. And the objective lens 10 are transmitted. The reflected light reflected from the sample 11 causes light interference only in this wavelength range. The reflected light (infrared light) reflected from the reference surface 13 and the reflected light (infrared light) reflected from the sample 11 are combined. This combined light has interference information.

  The combined light (infrared light) passes through the objective lens 10, is reflected by the dichroic mirror 603, and passes through the half mirror 16. One of the infrared light that has passed through the half mirror 16 passes through the third beam splitter 653. The infrared light that has passed through the third beam splitter 653 passes through the high-pass filter 601 a and is imaged by the first image sensor 651. The other of the infrared light transmitted through the half mirror 16 is reflected by the third beam splitter 653 and shielded or reflected by the low-pass filter 601b. Therefore, infrared light is not imaged by the second imaging element 652.

  Further, in the light 604 that has passed through the objective lens 10, visible light passes through the first beam splitter 12 and irradiates the sample 11 as in the seventh embodiment described above.

  The visible light reflected from the sample 11 passes through the first beam splitter 12 again based on the reflection transmittance characteristic of the first beam splitter 12 and passes through the objective lens 10. The light that passes through the objective lens 10 has no interference information.

  The visible light that has passed through the objective lens 10 passes through the objective lens 10, is reflected by the dichroic mirror 603, and passes through the half mirror 16. One of the visible lights that have passed through the half mirror 16 passes through the third beam splitter 653 and is shielded or reflected by the high-pass filter 601a. Therefore, visible light is not imaged by the first image sensor 651. The other visible light transmitted through the half mirror 16 is reflected by the third beam splitter 653. The reflected visible light passes through the low-pass filter 601b and is imaged by the second image sensor 652.

  Thus, the first image sensor 651 images infrared light that has passed through the high-pass filter 601a, and the second image sensor 652 images visible light that has passed through the low-pass filter 601b. As a result, the first image sensor 651 acquires an interference image, and the second image sensor 652 acquires a clear image (bright field image) with good contrast.

  The operation method of the confocal laser scanning type in this modification is the same as that in the seventh embodiment, and thus detailed description thereof is omitted.

  As described above, the interference microscope apparatus according to the present modification does not need to switch the high-pass filter 601a and the low-pass filter 601b by the filter switching mechanism 601 when acquiring the interference image and the bright-field image. can do. In addition, the interference microscope apparatus according to the present modification can simultaneously capture and acquire an interference image, a bright field image, and an observation image acquired by the confocal laser scanning microscope 610. Can be improved.

  In this modification, the third image splitter 653, the high-pass filter 601a, and the low-pass filter 601b cause the first image sensor 651 to pick up infrared light, and the second image sensor 652 causes the low-pass filter 601b to emit visible light. Is imaged. However, it is not necessary to limit to this configuration. The observation optical system 650 includes, for example, a third beam splitter 653, a high-pass filter 601a, and a light dividing unit that divides the light reflected from the sample 11 and the reference surface 13 according to desired spectral characteristics instead of the low-pass filter 601b. It may be arranged. The light splitting member is, for example, a fourth beam splitter (for example, a dichroic prism or a dichroic mirror) that transmits about 100% of infrared light and reflects about 100% of visible light. The reflection transmittance characteristic of the fourth beam splitter is substantially the same as that of the second beam splitter 19 shown in FIG. Thus, as in the modification, the first image sensor 651 images one light (infrared light) divided by the fourth beam splitter, and the second image sensor 652 is divided by the fourth beam splitter. The other light (visible light) is imaged.

Next, an eighth embodiment will be described with reference to FIGS. 27 and 28. FIG.
The same parts as those in the seventh embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 27 is a schematic diagram of an interference microscope apparatus according to the eighth embodiment. FIG. 28 is a schematic diagram of the sensor optical system.

  The interference microscope apparatus of the present embodiment includes a sensor optical system 710 that also serves as the objective lens 10 (interference objective lens 1) together with the first microscope, instead of the confocal laser scanning microscope 610 in the seventh embodiment described above. The half mirror 711 is disposed instead of the dichroic mirror 603.

  Since the configurations of the interference objective lens 1, the half mirror 16, the illumination optical system 600, and the observation optical system 605 of the present embodiment are the same as those of the seventh embodiment described above, detailed description thereof is omitted. The objective lens 10 (interference objective lens 1) of this embodiment is also used as the first microscope and the sensor optical system 710.

  The half mirror 711 has a spectral ratio such as a transmittance of about 30% and a reflectance of about 70%. The half mirror 711 transmits laser light (visible light) 705 emitted from a laser light source 701 described later, and transmits laser light 705 reflected from the sample 11 without being divided. As described above, the half mirror 711 transmits light without dividing it with respect to the wavelength of light emitted from the laser light source 701 disposed in the sensor optical system 710.

The sensor optical system 710 will be described with reference to FIG.
A sensor optical system 710 that is an autofocus sensor includes a laser light source 701 that emits laser light (visible light) 705, a condensing lens 702 that condenses visible light 705 emitted from the laser light source 701, and a condensing lens. A second beam splitter 703 that transmits visible light 705 collected by 702 and reflects visible light 705 reflected by a sample 11 to be described later, and visible light 705 that has passed through second beam splitter 703 is imaged. The second image forming lenses 704 are sequentially arranged.

  Note that the laser light source 701 may emit visible light (for example, light having a wavelength of about 680 nm or less) 705 that is transmitted through the first beam splitter 12. The second imaging lens 704 is disposed on the transmission optical path of the half mirror 711 described above.

  The visible light 705 projected by the second imaging lens 704 passes through the half mirror 711 and enters the interference objective lens 1 to irradiate the sample 11. At that time, the first beam splitter 12 which is a light splitting member transmits visible light 705 emitted from the laser light source 701. As described above, the sensor optical system 710 also serves as the objective lens 10 (interference objective lens 1) together with the first microscope.

  In the sensor optical system 710, a third beam splitter 720 that divides the visible light 705 reflected by the second beam splitter 703 is disposed on the reflected light path of the second beam splitter 703. The third beam splitter 720 transmits one of the divided visible lights 705 and reflects the other divided visible light 705.

  In addition, on the transmission optical path of the third beam splitter 720, the first pinhole 722a that allows the visible light 705 that has passed through the third beam splitter 720 to pass therethrough, and the visible light 705 that has passed through the first pinhole 722a. The first laser light receiving elements 721a for receiving light are sequentially arranged.

  On the reflected light path of the third beam splitter 720, the second pinhole 722b that allows the visible light 705 reflected by the third beam splitter 720 to pass therethrough and the visible light 705 that passes through the second pinhole 722b include Second light receiving elements 721b for receiving light are sequentially arranged.

  The first pinhole 722a is arranged behind the focal position of the second imaging lens 704 by a desired distance, and the second pinhole 722b is desired from the focal position of the second imaging lens 704. They are spaced apart forward. These desired intervals may be different or substantially the same.

  Since the operation methods of the illumination optical system 600, the half mirror 16, the interference objective lens 1, and the observation optical system 605 in the present embodiment are the same as those in the seventh embodiment, detailed description thereof is omitted.

Next, an operation method of the sensor optical system in the present embodiment will be described.
The visible light 705 emitted from the laser light source 701 is collected in a spot shape by the condenser lens 702, passes through the second beam splitter 703, and is imaged by the second imaging lens 704.

  The visible light 705 passes through the half mirror 711, is condensed on the sample 11 by the objective lens 10 of the interference objective lens 1, passes through the first beam splitter 12, and irradiates the sample 11. The visible light 705 does not generate interference information in the interference objective lens 1.

  The visible light 705 reflected from the sample 11 passes through the interference objective lens 1, the half mirror 711, and the second imaging lens 704 and is reflected by the second beam splitter 703. The visible light 705 reflected by the second beam splitter 703 is split by the third beam splitter 720. One of the divided visible lights 705 passes through the third beam splitter 720 and the first pinhole 722a, and is received by the first laser light receiving element 721a. The other visible light 705 is reflected by the third beam splitter 720, passes through the second pinhole 722b, and is received by the second laser light receiving element 721b.

  As described above, the first pinhole 722a is disposed behind the focal position of the second imaging lens 704, and the second pinhole 722b is disposed in front of the focal position of the second imaging lens 704. Has been. Accordingly, the distance is measured by referring to the balance of the light amounts of the light amounts received by the first laser light receiving element 721a and the second laser light receiving element 721b. This distance is the amount of deviation from the focus position of the interference objective lens 1 with respect to the sample 11. Thus, the sensor optical system 710 is an autofocus sensor.

  Since the visible light 705 used in the sensor optical system 710 does not interfere, interference information is not superimposed on the visible light 705 received by the first laser light receiving element 721a and the second laser light receiving element 721b. For this reason, the interference microscope apparatus according to the present embodiment has a stable operation of searching for a focus position by the sensor optical system 710 and a small amount of light loss due to the interference objective lens 1, and therefore refers to the amount of deviation measured in a good S / N state. Thus, the focus position can be determined, and the operability can be improved.

  Moreover, since the interference microscope apparatus of this embodiment can select a wavelength band (infrared region or visible region) by the filter switching mechanism 601, similarly to the seventh embodiment, it can easily and inexpensively use reference light. A bright-field image with good contrast without flare and an interference image can be acquired.

  In the present embodiment, the wavelength range in which the laser light source 701 emits the visible light 705 and interferes with the infrared region is not limited to this. For example, the wavelength in which the laser light source 701 emits the infrared light and interferes with it. The region may be a visible region. If the wavelength band is selected and interfered as described above, there is no need to limit it.

  In the present embodiment, the first laser light receiving element 721a is disposed behind the focal position of the second imaging lens 704, and the second laser light receiving element is disposed in front of the focal position of the second imaging lens 704. Although the element 721b is arranged, it is not necessary to limit to this. For example, the same effect can be obtained even if a sensor optical system using a knife edge method or an astigmatism method is arranged.

  Further, the present embodiment may be combined with the modification of the seventh embodiment described above.

FIG. 1 is a schematic diagram of an interference microscope apparatus according to the first embodiment. FIG. 2 shows the reflection transmittance characteristics of the first beam splitter in the first embodiment. FIG. 3 shows the reflection transmittance characteristics of the second beam splitter in the first embodiment. FIG. 4 shows the transmittance characteristics of the band-pass filter in the first embodiment. FIG. 5 is a diagram illustrating a first modification of the first embodiment, and is a diagram illustrating a schematic configuration of a Michelson interference objective lens. FIG. 6 is a diagram illustrating a second modification example of the first embodiment. The boundary is a wavelength region of 500 nm that is a visible light wavelength region, and a wavelength region having interference information and a wavelength region having no interference information. The reflection transmittance characteristics of the first beam splitter in the case of separation are shown. FIG. 7 is a diagram illustrating a second modification example of the first embodiment. The boundary is a wavelength region of 500 nm that is a visible light wavelength region, and a wavelength region having interference information and a wavelength region having no interference information. The reflection transmittance characteristics of the second beam splitter in the case of separation are shown. FIG. 8 is a diagram showing a second modification of the first embodiment, and shows the transmittance characteristics of the band-pass filter when the wavelength of 500 nm, which is the visible light region, is separated at the boundary. FIG. 9 is a diagram showing a third modification of the first embodiment, and shows a schematic configuration of the second beam splitter. FIG. 10 shows the reflection transmittance characteristics of the second beam splitter of the third modification example of the first embodiment. FIG. 11 shows the reflection transmittance characteristics of the second beam splitter of the third modification example of the first embodiment. FIG. 12 is a diagram showing a fourth modification example of the first embodiment, and shows the reflection transmittance characteristics of the first beam splitter. FIG. 13 is a schematic diagram of an interference microscope apparatus according to the second embodiment. FIG. 14 is a schematic diagram of an interference microscope apparatus according to the third embodiment. FIG. 15 shows the reflection transmittance characteristic of the first beam splitter in the second embodiment. FIG. 16 shows the spectral sensitivity characteristics of the wavelengths of the respective colors. FIG. 17 is a schematic diagram of a color image sensor. FIG. 18 is a schematic diagram of an interference microscope apparatus according to the fourth embodiment. FIG. 19 shows the transmittance characteristics of the band-pass filter in the fourth embodiment. FIG. 20 shows the transmittance characteristics of the band-pass filter in the fourth embodiment. FIG. 21 is a schematic diagram of an interference objective lens of an interference microscope apparatus according to the fifth embodiment. FIG. 22 shows the reflectance characteristics of the reference surface in the fifth embodiment. FIG. 23 is a schematic diagram of an interference microscope apparatus according to the sixth embodiment. FIG. 24 is a schematic diagram of an interference microscope apparatus according to the seventh embodiment. FIG. 25 is a schematic view of a confocal laser scanning microscope according to the seventh embodiment. FIG. 26 is a schematic diagram of an interference microscope apparatus showing a first modification of the seventh embodiment. FIG. 27 is a schematic diagram of an interference microscope apparatus according to the eighth embodiment. FIG. 28 is a schematic diagram of a sensor optical system according to the eighth embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Interference objective lens, 2 ... Observation optical system, 3 ... Illumination optical system, 10 ... Objective lens, 11 ... Sample, 12 ... 1st beam splitter, 13 ... Reference plane, 14 ... Light source, 15 ... Projection optical system, DESCRIPTION OF SYMBOLS 16 ... Half mirror, 17 ... Imaging lens, 18 ... Imaging element, 19 ... 2nd beam splitter, 20 ... Eyepiece lens, 21 ... Band pass filter, 22 ... Optical axis, 101 ... Interference objective lens, 112 ... 1st , 113 ... reference plane, 114 ... reflected light path, 120 ... second beam splitter, 121 ... second beam splitter, 122 ... imaging optical path, 123 ... visual observation optical path, 200 ... illumination optical system, 201 ... visible Light source, 202 ... Infrared light source, 203 ... Dichroic mirror, 204 ... Light emission optical path, 205 ... Light emission optical path, 206 ... Illumination optical axis, 249 ... Interference objective lens, 250 ... 251 ... color image sensor, 252 ... first beam splitter, 253 ... image sensor, 254 ... image sensor, 255 ... image sensor, 256 ... color separation prism, 300 ... observation optical system, 301 ... filter switching mechanism , 302 ... band pass filter, 303 ... band pass filter, 304 ... rotation center axis, 401 ... interference objective lens, 402 ... first beam splitter, 403 ... reference plane, 500 ... index projection optical system, 501 ... light source, 502 ... Condensing lens, 503 ... Half mirror, 504 ... Indicator pattern, 505 ... Projection lens, 506 ... Projection image

Claims (38)

An objective lens for irradiating the sample with light;
A light dividing member that is disposed between the sample and the objective lens and transmits one light by dividing the light and reflects the other light;
A reference surface disposed on the optical path divided by the light splitting member and irradiated by the light reflected from the light splitting member;
An interference objective lens comprising:
The light splitting member splits only the light in a desired wavelength range at a desired ratio to transmit or reflect the light, or the reference surface reflects only the light in a desired wavelength range. An interference objective lens.   The interference objective according to claim 1, wherein the light dividing member divides only the light in the infrared region at a desired ratio, or the reference surface reflects only the light in the infrared region. lens.   The interference objective lens according to claim 1, wherein the light splitting member includes a beam splitter, and splits only the light having a desired wavelength by the beam splitter at a desired ratio.   The interference objective lens according to claim 3, wherein the beam splitter further includes a dichroic prism or a dichroic mirror. A light source that emits light to the sample;
An objective lens that irradiates the sample with the light emitted from the light source;
A first light splitting member disposed between the objective lens and the sample and transmitting one of the lights by splitting the light and reflecting the other light;
A reference surface disposed on the optical path divided by the first light splitting member and irradiated by the other light reflected from the first light splitting member;
An interference objective having
An observation optical system for observing an interference image by forming an image of the light reflected from the sample that interferes with the light reflected from the reference surface;
An interference microscope apparatus comprising:
The first light dividing member divides only the light in a desired wavelength range at a desired ratio, or the reference surface reflects only the light in a desired wavelength range, and the observation optical system includes: An interference microscope apparatus characterized in that the interference image is observed by forming the light in a desired wavelength region. The observation optical system is
At least one second light splitting member that splits only the light in a desired wavelength range at a desired ratio;
An observation unit arranged on at least one optical path divided by the second light dividing member and observing the interference image;
The interference microscope apparatus according to claim 5, further comprising:   The interference microscope apparatus according to claim 6, wherein the second light splitting member includes a dichroic prism or a dichroic mirror that reflects or transmits the light in the wavelength range according to the wavelength range. .   The interference microscope apparatus according to claim 6, wherein the second light splitting member is arranged to be replaceable or switchable on an optical path. The observation optical system is
An imaging unit that captures the interference image according to the wavelength range;
Have
The interference microscope apparatus according to claim 5, wherein the observation optical system selects and observes an image for each color component received by the imaging unit.   The first light splitting member transmits the light having a wavelength less than or equal to the center wavelength of the green wavelength range, splits the light amount of the light having a wavelength equal to or greater than the center wavelength of the green wavelength range at a desired ratio, and the observation optical system Selects the image of the red component received by the imaging unit and observes it as an interference image, and the observation optical system selects the image of the blue component received by the imaging unit and observes it as a non-interference image The interference microscope apparatus according to claim 9. The observation optical system is
A band-pass filter disposed on the optical path of the observation optical system and having a different transmittance depending on the transmitted light;
The interference microscope apparatus according to claim 5, further comprising:   The interference microscope apparatus according to claim 11, wherein the band-pass filter is replaceable or switchable on the optical path.   The interference microscope apparatus according to claim 5, wherein the light source continuously emits the light from a visible region to an infrared region.   The interference microscope apparatus according to claim 5, wherein the plurality of light sources independently emit the light in at least two different wavelength ranges, respectively, and independently adjust the light amount of the light. For projection, comprising: an index pattern arranged at a position optically conjugate with the object side focal position of the interference objective lens; and a pattern projection light source for projecting the index pattern onto the object side focal position of the interference objective lens Optical system,
Further comprising
The interference microscope apparatus according to claim 5, wherein the light source for pattern projection emits the light in a wavelength region that transmits the first light splitting member of the interference objective lens. A light source that emits light from the visible range to the infrared range on the sample;
An objective lens that irradiates the sample with the light emitted from the light source;
A first light splitting member disposed between the objective lens and the sample and transmitting one of the lights by splitting the light and reflecting the other light;
A reference surface disposed on the optical path divided by the first light splitting member and irradiated by the other light reflected from the first light splitting member;
An interference objective having
An observation optical system for observing an interference image by forming an image of the light reflected from the sample that interferes with the light reflected from the reference surface;
An interference microscope apparatus comprising:
The first light splitting member splits only the light in the infrared region at a desired ratio, or the reference surface reflects only the light in the infrared region, and the observation optical system has the visible optical system. An interference microscope apparatus characterized in that the interference image is observed by forming the light in the region or the light in the infrared region. The observation optical system is
At least one second light splitting member that splits only the light in a desired wavelength range at a desired ratio;
An observation unit arranged on at least one optical path divided by the second light dividing member and observing the interference image;
The interference microscope apparatus according to claim 16, comprising:   18. The interference microscope apparatus according to claim 17, wherein the second light splitting member includes a dichroic prism or a dichroic mirror that reflects or transmits the light in the wavelength range according to the wavelength range. .   The interference microscope apparatus according to claim 17, wherein the second light splitting member is replaceable or switchable on the optical path. The observation optical system is
An imaging unit that captures the interference image according to the wavelength range;
Have
The interference microscope apparatus according to claim 16, wherein the observation optical system selects and observes an image for each color component received by the imaging unit. The observation optical system is
A bandpass filter that is disposed on the optical path of the observation optical system and transmits the light in the desired visible range;
The interference microscope apparatus according to claim 16, comprising:   The interference microscope apparatus according to claim 21, wherein the band-pass filter is replaceable or switchable on the optical path.   The interference light source device according to claim 16, wherein the light source continuously emits the light from a visible region to an infrared region. Projection optics comprising: an index pattern arranged at a position optically conjugate with the object side focal position of the interference objective lens; and a pattern projection light source that projects the index pattern onto the object side focal position of the interference objective lens. The system,
Further comprising
17. The interference microscope apparatus according to claim 16, wherein the pattern projection light source emits the light in a wavelength region that transmits the first light splitting member of the interference objective lens. A light source that emits light to the sample;
An objective lens that irradiates the sample with the light emitted from the light source;
A first light splitting member disposed between the objective lens and the sample and transmitting one of the lights by splitting the light and reflecting the other light;
A reference surface disposed on the optical path divided by the first light splitting member and irradiated by the other light reflected from the first light splitting member;
An interference objective having
An observation optical system for observing an interference image by forming an image of the light reflected from the sample that interferes with the light reflected from the reference surface;
A first microscope having:
An interference microscope apparatus comprising:
A second microscope different from the first microscope that also serves as the objective lens together with the first microscope;
Comprising
The first light dividing member divides only the light in a desired wavelength range at a desired ratio, or the reference surface reflects only the light in a desired wavelength range, and the observation optical system includes: An interference microscope apparatus characterized in that the interference image is observed by forming the light in a desired wavelength region.   The interference microscope apparatus according to claim 25, wherein the second microscope is a confocal microscope.   27. The interference microscope apparatus according to claim 25, wherein the second microscope is a confocal laser scanning microscope.   26. The interference according to claim 25, wherein the first light splitting member transmits light without splitting the wavelength of light emitted from a light source disposed in the second microscope. Microscope device.   The interference microscope apparatus according to any one of claims 25 to 28, wherein the light source arranged in the second microscope emits visible light. The first microscope is:
A first transmission filter having a desired threshold and transmitting light in a wavelength region equal to or greater than the threshold from the light emitted from the light source;
A second transmission filter having the threshold value and transmitting light in a wavelength region equal to or less than the threshold value from the light emitted from the light source;
Have
26. The interference microscope apparatus according to claim 25, wherein the first microscope is configured such that one of the first transmission filter and the second transmission filter is replaceable on the optical axis. The observation optical system is
A first transmission filter having a desired threshold and transmitting light in a wavelength region equal to or greater than the threshold from the light emitted from the light source;
A second transmission filter having the threshold value and transmitting light in a wavelength region equal to or less than the threshold value from the light emitted from the light source;
An imaging unit that images the light in the wavelength range equal to or greater than the threshold value that has passed through the first transmission filter, and the light in the wavelength range that is equal to or less than the threshold value that has passed through the second transmission filter;
Have
The observation optical system is arranged so that either the first transmission filter or the second transmission filter can be exchanged on the optical axis, and the imaging unit includes the first transmission filter that has the optical axis. When the second transmission filter is disposed on the optical axis, the light in the wavelength region equal to or less than the threshold is imaged when the light is disposed on the optical axis. The interference microscope apparatus according to claim 25.   32. The interference microscope apparatus according to claim 31, wherein the imaging unit is a color imaging element. The observation optical system is
A light splitting member for splitting the light reflected from the sample and the reference surface according to desired spectral characteristics;
A first transmission filter that transmits light in a wavelength range equal to or greater than a desired threshold value from one of the lights divided by the light dividing member;
A first imaging unit that images the light transmitted through the first transmission filter;
A second transmission filter that transmits light in a wavelength range equal to or less than a desired threshold from the other light divided by the light dividing member;
A second imaging unit that images the light transmitted through the second transmission filter;
26. The interference microscope apparatus according to claim 25, comprising: The observation optical system is
A light splitting member for splitting the light reflected from the sample and the reference surface according to desired spectral characteristics;
A first imaging unit that images one of the lights divided by the light dividing member;
A second imaging unit that images the other light divided by the light dividing member;
26. The interference microscope apparatus according to claim 25, comprising: A light source that emits light to the sample;
An objective lens that irradiates the sample with the light emitted from the light source;
A first light splitting member disposed between the objective lens and the sample and transmitting one of the lights by splitting the light and reflecting the other light;
A reference surface disposed on the optical path divided by the first light splitting member and irradiated by the other light reflected from the first light splitting member;
An interference objective having
An observation optical system for observing an interference image by forming an image of the light reflected from the sample that interferes with the light reflected from the reference surface;
A first microscope having:
An interference microscope apparatus comprising:
A sensor optical system that also serves as the objective lens together with the first microscope;
Comprising
The first light dividing member divides only the light in a desired wavelength range at a desired ratio, or the reference surface reflects only the light in a desired wavelength range, and the observation optical system includes: An interference microscope apparatus characterized in that the interference image is observed by forming the light in a desired wavelength region.   36. The interference microscope apparatus according to claim 35, wherein the sensor optical system is an autofocus sensor.   36. The interference microscope according to claim 35, wherein the first light splitting member transmits light without splitting the wavelength of light emitted from a light source disposed in the sensor optical system. apparatus.   38. The interference microscope apparatus according to any one of claims 35 to 37, wherein the light source disposed in the sensor optical system emits visible light.

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