JP5385206B2 - Photometric device - Google Patents

Description

  The present invention relates to a photometric device, and more particularly, to a microphotometric device that measures a reflectance or the like on a measurement surface of a test object.

Conventionally, a microphotometer has been used to measure the reflectance and the like of a measurement surface of an object such as an optical element (see, for example, Patent Document 1).
FIG. 8 is a diagram showing a schematic configuration of the photometric device described in Patent Document 1. As shown in FIG. A measurement light beam emitted from the light source 101 passes through the illumination lens 102 and enters the pinhole 103. The measurement light beam that has passed through the pinhole 103 becomes parallel light by the collimator lens 104, is incident on the objective lens 106 below by the half mirror 105, and is irradiated on the test object 107. On the measurement surface 108 of the test object 107, the measurement light beam is reflected to become a reflected light beam, passes through the objective lens 106 again, and enters the condenser lens 109.

  Above the condensing lens 109, an eyepiece unit 110 for taking out a part of the collected reflected light beam and observing the image, and a spectroscopic unit 111 for detecting the spectral spectrum intensity are provided. The spectroscopic unit 111 is provided with a diffraction grating 112 that decomposes the reflected light beam into a spectral spectrum for each wavelength. The light decomposed into the spectral spectrum by the diffraction grating 112 forms an image on the CCD 113 which is a one-dimensional solid-state imaging device. The signal converted from the light intensity signal from the CCD 113 into an electrical signal is processed by the data processing unit 114, whereby the spectral reflectance of the measurement surface 108 is measured and calculated.

Japanese Patent No. 2806747

  In general, a coating applied to an optical element or the like has an angle dependency, and the reflectance and transmittance change when the incident angle to the optical element is different. In particular, in the case of an optical element having a curvature, it is difficult to perform coating uniformly over the entire area of the optical element, and therefore the reflectance and transmittance are often different between the top surface and the peripheral edge. Therefore, in the measurement using the photometric device, the optical axis of the measurement light beam incident on the test object is held at a constant angle with respect to the measurement surface of the test object, and the measurement light beam to the test object In order to perform measurement with high accuracy and high reproducibility, it is important that the measurement surface is always irradiated to a certain region and the same region is a measurement target.

  In the photometric device described in Patent Document 1, when the measurement surface 108 of the test object 107 is arranged slightly inclined with respect to the optical axis of the measurement light beam as shown by a broken line in FIG. The reflected light beam is shifted as indicated by the broken line. Therefore, when the aperture of the objective lens 106 or a stop is provided, a part of the reflected light beam does not enter the condenser lens 109 by the stop, and the amount of the reflected light beam that enters the eyepiece lens unit 110 and the spectroscopic unit 111. Changes slightly.

  However, even if the reflected light beam is shifted, the image forming position by the condensing lens 109 and the position of the image observed by the eyepiece lens unit 110 do not change. It is hard to notice that is inclined. As a result, there is a problem that the measurement is performed with the measurement surface tilted, and the accuracy and reproducibility of the measurement may not be sufficient.

  In addition, when the measurement surface is a spherical surface, even if the optical axis of the test object and the optical axis of the measurement light beam are parallel, if the measurement light beam deviates from the surface top position, it is the same as the above-described inclined arrangement. It becomes a state. Also in this case, since the image forming position by the condenser lens and the position of the image observed by the eyepiece lens portion do not change, the user is hardly aware of this, and the posture of the test object is not corrected. In addition, measurement accuracy and reproducibility may be insufficient.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a photometric device capable of easily confirming and adjusting the position and posture of a test object.

  The photometric device of the present invention comprises a light source, an objective optical system that guides the measurement light beam emitted from the light source to the test object, and photometry for measuring the reflected light beam reflected by the measurement surface of the test object. An alignment state confirmation unit including an imaging unit that is disposed on an optical path of the reflected light beam and that captures an image of the reflected light beam at a position different from a focal point of the reflected light beam, and the imaging unit And a display unit for displaying information obtained from the image of the reflected light beam imaged in (1).

  The alignment state confirmation unit may include a collimator lens, and the reflected light beam may be imaged by the imaging unit after being converted into parallel light.

  The alignment state confirmation unit may include a calculation unit that calculates an alignment amount indicating an alignment state of the test object based on the image of the reflected light beam captured by the imaging unit.

  The objective optical system may be configured by disposing a concave mirror and a convex mirror with their mirror surfaces facing each other.

The calculation unit may calculate the position of the center of gravity of the inner region of the reflected light flux image having an annular shape as the alignment amount.
The calculation unit may calculate the area of the inner region of the reflected light beam image as the alignment amount, or may calculate the ratio of the area in the inner region to the perimeter as the alignment amount.

  According to the photometric device of the present invention, the position and posture of the test object can be easily confirmed and adjusted.

It is a schematic diagram which shows schematic structure of the photometry apparatus of 1st Embodiment of this invention. (A) And (b) is a figure which shows the example of the reflected light beam image acquired with the 2nd image pick-up element of the alignment state of a test object etc., and the same photometry apparatus, respectively. (A) is a figure explaining the alignment amount calculation method in the photometry apparatus of 2nd Embodiment of this invention, (b) and (c) are both figures which show the example of a reflected light beam image and its gravity center position. It is. (A) And (b) is a figure which shows the objective optical system in the photometry apparatus of 3rd Embodiment of this invention, and the aspect of a measurement light beam and a reflected light beam. (A) And (b) is a figure which shows the image which the 2nd image sensor after the binarization process acquired. It is a figure explaining the calculation method of the alignment amount in the modification of the embodiment. It is a figure explaining the calculation method of the alignment amount in the other modification of the embodiment. It is a figure which shows schematic structure of the conventional photometry apparatus.

  A first embodiment of the present invention will be described with reference to FIGS. 1 to 2B. FIG. 1 is a schematic diagram showing a schematic configuration of a photometric device 50 of the present embodiment. As shown in FIG. 1, the photometric device 50 illuminates the measurement surface Sa of the test object S or the reference measurement surface SPa of the reference sample SP having a known spectral reflectance, thereby allowing the measurement surface Sa and the reference measurement surface. The spectral intensity of the SPa is measured, and the relative spectral reflectance of the measurement surface Sa with respect to the reference measurement surface SPa is calculated from the obtained measured values of the spectral intensity.

  The photometric device 50 includes a light source unit 10 having a light source 1, an objective optical system 15 that guides the measurement light beam emitted from the light source 1 to the test object S, and the measurement light beam reflected by the measurement surface Sa of the test object S. A spectroscope (photometry means) 20 that measures the reflected light beam, an observation optical system 30 for observing the reflected light beam, and a test object S or a reference sample SP (hereinafter referred to as “test object S etc.”). The alignment state confirmation unit 40 for confirming the alignment state of FIG.

The light source unit 10 includes a light source 1, an illumination lens 2, a pinhole diaphragm 3, and a collimator lens 4.
The light source 1 generates a measurement light beam for illuminating the measurement surface Sa and the reference measurement surface SPa (hereinafter sometimes referred to as “measurement surface Sa”). For example, a halogen lamp or a deuterium lamp is used. Can be adopted. Depending on the measurement purpose, a light source composed of a light emitting element such as a light emitting diode or a semiconductor laser may be used.

The illumination lens 2 is an optical element that illuminates the pinhole diaphragm 3 with a measurement light beam generated by the light source 1.
The pinhole diaphragm 3 is a diaphragm member including a pinhole that limits the range of the measurement light beam illuminated by the illumination lens 2 and illuminates a part of the measurement surface Sa and the like in a spot shape.
The collimator lens 4 is a lens or a lens group disposed so that the focal position coincides with the pinhole so that the measurement light beam emitted from the pinhole diaphragm 3 is a parallel light beam. A part of the measurement light beam transmitted through the collimator lens 4 is guided to the objective optical system 15 by the half mirror 5.

The objective optical system 15 includes an objective lens 16 and a diaphragm 17.
The objective lens 16 condenses the measurement light beam incident from the half mirror 5 on the measurement surface Sa or the like of the test object S or the like placed perpendicular to the optical axis X1 of the measurement light beam and is reflected by the measurement surface Sa or the like. A lens or a lens group that collects the reflected light flux. The opening of the objective lens 16 is defined to have a predetermined diameter by the diaphragm 17.

  The test object S and the reference sample SP are held on the stage 6. The stage 6 has a known configuration, and can move the measurement surface Sa or the reference measurement surface SPa in a direction parallel to and perpendicular to the optical axis X1. Further, the angle formed with respect to the optical axis X1 can be adjusted, whereby the inclination of the test object S or the like held on the stage 6 with respect to the optical axis X1 can be adjusted.

The reflected light beam that has passed through the objective optical system 15 passes through the half mirror 5 and then forms an image on the entrance aperture 20 a of the spectroscope 20 by the imaging lens 7.
The spectroscope 20 includes a diffraction grating 21 and a one-dimensional image sensor 22. The diffraction grating 21 decomposes the reflected light beam incident from the incident aperture 20 a for each wavelength and forms an image at different pixel positions of the one-dimensional image sensor 22. The one-dimensional image sensor 22 outputs an output signal corresponding to the amount of received light for each pixel.

  A part of the reflected light beam from the imaging lens 7 toward the spectroscope 20 is branched by the first beam splitter 8 toward the observation optical system 30 and the alignment state confirmation unit 40, and further, the observation optical system 30 by the second beam splitter 9. And it branches toward each of the alignment state confirmation part 40.

The observation optical system 30 includes a first image sensor 31. The first image sensor 31 is disposed at the condensing point of the imaging lens 7 and projects an image of the measurement surface Sa or the like.
The alignment state confirmation unit 40 includes a collimator lens 41 and a second imaging element (imaging means) 42. The collimator lens 41 is arranged so that its focal point coincides with the focal point of the imaging lens 7, and the reflected light beam that has become parallel light by the collimator lens 41 is projected onto the second image sensor 42. That is, the second image sensor 42 is installed on the optical path of the reflected light beam and at a position different from the condensing point of the imaging lens 7 that becomes the focal point of the reflected light beam.

  The spectroscope 20, the first image sensor 31, and the second image sensor 42 are electrically connected to a personal computer (control unit) 45 including a display unit 46 and an operation unit 47. The personal computer 45 performs an arithmetic process on the output signal sent from the spectroscope 20 to calculate the relative spectral reflectance, and displays the calculation result on the display unit 46. The images acquired by the first image sensor 31 and the second image sensor 42 are sent to the personal computer 45 and displayed on the display unit 46. The user can switch the displayed image by appropriately operating the operation unit 47.

The operation at the time of using the photometric device 50 configured as described above will be described. The spectral reflectance measurement procedure using the photometric device 50 is basically the same as that of a conventional photometric device, but is briefly described as follows.
A measurement light beam emitted from the light source 1 passes through the illumination lens 2, the pinhole diaphragm 3, and the collimator lens 4, is reflected by the half mirror 5, and enters the objective optical system 15. The measurement light beam forms an image on the measurement surface Sa of the test object S held on the stage 6, and then is reflected by the measurement surface Sa to become a reflected light beam.
The reflected light beam passes through the half mirror 5, then enters the spectroscope 20 by the imaging lens 7, is decomposed for each wavelength by the diffraction grating 21, and forms an image on the one-dimensional image sensor 22. The signal output from the one-dimensional image sensor 22 is sent to the personal computer 45, and when a predetermined calculation is performed, the spectral reflectance of the measurement surface Sa of the test object S is calculated.

Next, the measurement flow of the user in the measurement of the relative spectral reflectance using the photometric device 1 will be described.
First, the user places the reference sample SP on the stage 6, moves the stage 6 in parallel with the optical axis X <b> 1, and adjusts the reference measurement surface SPa to coincide with the imaging position of the objective lens 16. At the time of adjustment, the image Im1 including the image of the reflected light beam acquired by the first image pickup device 31 of the observation optical system 30 is displayed on the display unit 46, and the image of the reflected light beam becomes the in-focus position while viewing the image Im1. Adjust to.

  Next, the stage 6 is moved in the direction perpendicular to the optical axis X1 and adjusted so that the reference measurement surface SPa is positioned at an appropriate measurement position. This adjustment is performed, for example, while viewing the measurement light beam projected onto the reference measurement surface SPa.

  Finally, the user operates the stage 6 to adjust the inclination of the stage 6 with respect to the optical axis X1. In this adjustment, the user switches the display on the display unit 46 to the image Im2 including the image of the reflected light beam captured by the second imaging element 42 of the alignment state confirmation unit 40, and performs the adjustment while viewing the image.

  FIGS. 2A and 2B are diagrams illustrating an example of an alignment state of the test object S and the like and an image Im2 acquired by the second imaging element 42. FIG. The reflected light beam reflected by the reference measurement surface SPa is projected onto the second image sensor 42 through the diaphragm 17 of the objective optical system 15. If the reference measurement surface SPa is held perpendicular to the optical axis X1, the reflected light beam preferably passes through the diaphragm 17, and the reflected light image Im21 in the image Im2 is as shown in FIG. Becomes a perfect circle.

  On the other hand, when the reference measurement surface SPa has an inclination with respect to the optical axis X1, as shown in FIG. 2B, the reflected light side is in a predetermined direction (in this embodiment, the right direction in FIG. 2B). It shifts, and part of it is blocked by the diaphragm 17 and does not reach the second image sensor 42. At this time, the image Im22 of the reflected light beam in the image Im2 is semicircular and has no change in the shape of the right half that is forward in the shift direction of the reflected light beam, but is smaller than the semicircle in the left half region that is behind the shift direction. It becomes no circle. While viewing the image Im22 displayed on the display unit 46, the user adjusts the tilt of the stage 6 so that the image Im22 approaches the image Im21 in a perfect circle state, so that the reference measurement surface SPa is relative to the optical axis X1. Thus, the alignment of the reference sample SP can be adjusted to be vertical (including substantially vertical).

When the alignment adjustment of the reference sample SP is completed, the user inputs a measurement start command to the personal computer 45 via the operation unit 47. The output signal of the one-dimensional imaging device 22 acquired in the above flow is stored as it is in a storage area (not shown) of the personal computer 45 as spectral intensity data R _a (λ) of the reference sample SP.
If the spectral intensity data R _a (λ) has already been stored in the personal computer 45 in the previous measurement, the procedure up to this point may be omitted as necessary.

Next, the user replaces the reference sample SP with the specimen S and installs the specimen S on the stage 6. Then, the alignment of the test object S is adjusted so that the measurement surface Sa makes an appropriate angle with respect to the optical axis X1 by the same procedure as that performed for the reference sample SP. When the measurement surface Sa has a curvature, only the movement in the parallel and vertical directions with respect to the optical axis X1 may be performed without adjusting the tilt of the stage 6.
When the user inputs a measurement start command to the personal computer 45 after the alignment adjustment of the test object S is completed, the output signal of the one-dimensional image sensor 22 is sent to the personal computer 45, and the spectral intensity data R _b ( λ) is stored in the storage area of the personal computer 45.
The personal computer 45 uses the spectral intensity data R _a (λ) and R _b (λ) to calculate the relative spectral reflectance R _result (λ) of the measurement surface Sa according to the following formula 1, and stores it in the storage area. . In _Equation 1, R _theory (λ) refers to spectral reflectance data of the reference sample SP.

The photometric device 50 of this embodiment includes an alignment state confirmation unit 40 having a second image sensor 42 that captures an image of a reflected light beam at a position different from the focal point of the reflected light beam. For this reason, the reflected light beam image captured by the second image sensor 42 is different from the reflected light beam image captured by the first image sensor 41 of the observation optical system 30, and changes such as the inclination of the test object S with respect to the optical axis X1. As the shape changes, the shape changes.
Therefore, the user can easily confirm even if there is a slight shift in the alignment state of the test object S or the like by viewing the image of the reflected light beam captured by the second image sensor 42. By adjusting the stage 6 while viewing the image, the test object S and the like can be easily adjusted to a suitable alignment state. As a result, measurement with higher accuracy and higher reproducibility can be performed.

  Further, since the alignment state confirmation unit 40 includes the collimator lens 42, the reflected light beam enters the second image sensor 42 as parallel light. Therefore, even when the second image sensor is arranged far away from the focal point of the reflected light beam, the diameter of the reflected light beam does not depart from the imaging range of the second image sensor and is suitable for the second image sensor. In addition, an image of the reflected light beam can be taken.

  Next, a second embodiment of the present invention will be described with reference to FIGS. 3 (a) to 3 (c). The difference between the photometric device of the present embodiment and the photometric device 50 of the first embodiment described above is that the alignment amount is calculated based on the information acquired by the alignment state confirmation unit. In the following description, components that are the same as those already described are assigned the same reference numerals and redundant description is omitted.

In this embodiment, the position of the center of gravity of the reflected light beam image (hereinafter referred to as “reflected light beam image”) is calculated as the alignment amount. The calculation method will be described below.
The second image sensor 42 has a plurality of pixels, and the reflected light beam image Im20 is divided for each pixel as indicated by a broken line in FIG. Position of each pixel in the horizontal direction, where W is the number of pixels in the horizontal direction (left and right direction in FIG. 3A) of the second image sensor 42 and H is the number of pixels in the vertical direction (up and down direction in FIG. 3A). I (i = 0, 1,..., W−1), the vertical position j (j = 0, 1,..., H−1), the horizontal position i, and the vertical position j. If the luminance value is g [i] [j], the coordinates (X, Y) of the center of gravity position of the reflected light beam image can be calculated according to the following equation (2).
The center of gravity position of the reflected light beam image is the center (X1,...) Of the circular reflected light beam image Im21 shown in FIG. 3B if the measurement surface Sa or the like of the test object S is perpendicular to the optical axis X1. Y1). When the measurement surface is inclined with respect to the optical axis X1, the reflected light beam image is deformed, for example, as a reflected light beam image Im22 shown in FIG. 3C, and the position of the center of gravity is also deviated from the center of the reflected light beam image Im1. Move to (X2, Y2).

The calculation of the center of gravity position is performed by the personal computer 45. That is, in the photometric device of the present embodiment, the personal computer 45 also functions as an arithmetic unit that calculates the alignment amount.
The position of the center of gravity calculated by the personal computer 45 is displayed on the display unit 46, but there is no particular limitation on the form thereof, and numerical display may be used, or a cursor such as a dot or a cross may be displayed superimposed on the reflected light beam image. . When displayed as a numerical value, it may be displayed as a deviation amount from the position of the center of gravity in a desired alignment state (for example, a state in which the reflected light beam image is a perfect circle like Im21).
While viewing the barycentric position of the reflected light beam image as the alignment amount displayed on the display unit 46, the user moves the barycentric position to a desired position so that the test object S and the like are in a suitable alignment state. Adjust 6.

Also in the photometric device of this embodiment, as in the first embodiment, the alignment state of the test object S or the like can be easily confirmed, and the alignment state of the test object S or the like can be suitably adjusted. As a result, measurement with higher accuracy and higher reproducibility can be performed.
Further, since the personal computer 45 calculates the center of gravity position of the reflected light beam image as the alignment amount of the test object S based on the reflected light beam image captured by the second image sensor 42 and displays it on the display unit 46, the user Can more easily adjust the alignment of the specimen S or the like while referring to the position of the center of gravity.

  Next, a third embodiment of the present invention will be described with reference to FIGS. 4 (a) to 5 (b). The difference between the photometric device of this embodiment and the photometric device 50 of the first embodiment described above is the configuration of the objective optical system and the calculation method of the alignment amount.

  FIGS. 4A and 4B are diagrams showing the objective optical system 60 in the photometric device of the present embodiment, and the modes of the measurement light beam and the reflected light beam. The objective optical system 60 is configured by arranging a concave mirror 61 with a hole and a convex mirror 62 with their mirror surfaces facing each other. Although the objective optical system 60 is not provided with the diaphragm 17, a part of the measurement light beam is blocked by the annular aperture diaphragm determined by the concave mirror 61 and the convex mirror 62, and reaches the test object S or the like.

  In the convex mirror 62, since the reflected light beam from the measurement surface Sa or the like does not reach a partial region near the top of the surface, the reflected light beam image acquired by the second imaging element 42 of the alignment state confirmation unit 40 is the measurement surface Sa or the like. Is perpendicular to the optical axis X1, it becomes a regular circular zone like a reflected light beam image Im23 shown in FIG. When the measurement surface Sa or the like is tilted with respect to the optical axis X1, the annular shape of the reflected light beam image is deformed, for example, as a reflected light beam image Im24 shown in FIG.

A method for calculating the alignment amount in the present embodiment will be described.
First, the personal computer 45 as the calculation unit performs binarization processing on the image Im2 including the reflected light beam image acquired by the second imaging element 42 according to a preset threshold value. Then, as shown in FIGS. 5A and 5B, the image Im2 includes a reflected light beam image Im23 or Im24, an external region R1 outside the reflected light beam image, and an internal region surrounded by the reflected light beam image. Divided into three regions with R2. The personal computer 45 uses the pixels of the second image sensor 42 corresponding to the inner region R2, and uses the same procedure as in the second embodiment to display the position of the center of gravity of the inner region R2 (see FIGS. 5A and 5B). Calculated as C1 and C2, respectively). The calculated position of the center of gravity of the internal region R2 can be used as the alignment amount of the test object S or the like for confirmation and adjustment of the alignment state of the test object S or the like as described in the second embodiment. .

  Also with the photometric device of the present embodiment, the alignment state of the test object S or the like can be easily confirmed and adjusted to a suitable alignment state, as in the above embodiments. As a result, measurement with higher accuracy and higher reproducibility can be performed.

  The objective optical system 60 is composed of a combination of a concave mirror 61 and a convex mirror 62, and is composed only of a mirror surface. Therefore, the objective optical system 60 has small chromatic aberration and is not affected by the non-transmission wavelength due to the glass material. Therefore, a photometric device capable of supporting a wider wavelength range can be obtained.

  In the above-described second embodiment and the present embodiment, the example in which the center of gravity position of the reflected light beam image is calculated based on the luminance in each pixel of the reflected light beam image has been described. However, various known methods can be appropriately selected and used.

  Further, when the objective optical system is a combination of a concave mirror and a convex mirror as in this embodiment, it is possible to use parameters other than the center of gravity position as the alignment amount. Below, such a modification is demonstrated.

  FIG. 6 is a diagram illustrating an alignment amount calculation method according to the first modification of the present embodiment. In the present modification, the personal computer 45 performs the binarization process on the image including the reflected light beam image acquired by the second image sensor as described above, and then the total number N of pixels Px located inside the internal region R2. Is displayed on the display unit 46 as an alignment amount indicating the area of the internal region R2. If the measurement surface Sa or the like is a flat surface, the area of the internal region R2 is minimum when the measurement surface Sa or the like is perpendicular to the optical axis X1, and the total number of pixels N is also minimum. Therefore, the user can easily adjust the alignment of the test object S or the like by adjusting the stage 6 so that the total number of pixels N is minimized.

Note that the total number of pixels N indicating the optimum alignment state varies depending on the shape of the measurement surface. Therefore, in actuality, the total number of pixels N _alg upon completion of adjustment assumed on each measurement surface is calculated, By performing parallel display with the total number of pixels N, it may be used as an index for alignment adjustment. The display format can be displayed as an indicator such as a bar graph in addition to numerical values.

FIG. 7 is a diagram illustrating a method for calculating the alignment amount in the second modification of the present embodiment. In the present modification, after performing the binarization processing of the image including the reflected light beam image as described above, the personal computer 45 has the outermost edge as shown in FIG. 7 among the pixels located inside the internal region R2. A peripheral length L, which is a length connecting pixels, is calculated. In FIG. 7, since the pixel Px is displayed large for convenience of explanation, the figure indicating the peripheral length L is not a circle but a square, but actually, the pixel Px is small and there are many pixels. For this reason, the graphic indicating the peripheral length L has substantially the same shape as the inner region R2. The calculated peripheral length L is stored in the storage area of the personal computer 45.
Further, the personal computer 45 counts the total number of pixels N in the internal region R2 in the same procedure as in the first modification, and calculates the alignment amount using the peripheral length L and the total number of pixels N. There are several formulas for the calculation. For example, the following formula 3 can be used. When Expression 3 is used, if the measurement surface Sa or the like is a flat surface, the alignment amount becomes 1 when the measurement surface Sa or the like is perpendicular to the optical axis X1, and thus the user approaches the alignment amount to 1. The alignment adjustment may be performed.

  In addition, the following equations 4 and 5 can be used to calculate the alignment amount. In the case of Equation 4, when the measurement surface Sa or the like is a flat surface, the alignment amount is 1 / 4π when the measurement surface Sa is perpendicular to the optical axis X1, and 1 in the case of Equation 5.

  The embodiments of the present invention have been described above. However, the technical scope of the present invention is not limited to the above-described embodiments, and combinations of components in the embodiments may be changed without departing from the spirit of the present invention. Various changes can be added to or deleted from each component.

  For example, in each of the above-described embodiments, the example in which the alignment state confirmation unit is disposed at a position farther than the focal point in the optical path of the reflected light beam is described. However, the change in the reflected light beam image that reflects the alignment state is The reflected light beam image can be captured at a position different from the focal point. Therefore, the alignment state confirmation unit may be disposed at a position closer to the focal point in the optical path of the reflected light beam.

Further, a plurality of types of alignment amounts described above may be calculated and displayed on the display unit.
Furthermore, an image including the reflected light beam image acquired by the alignment state confirmation unit may not be displayed on the display unit, and only the image acquired by the observation optical system and the calculated alignment amount may be displayed on the display unit. .

1 Light source 15, 60 Objective optical system 20 Spectrometer (photometric means)
40 Alignment state confirmation unit 42 Second image sensor (imaging means)
41 Collimator lens 45 PC (calculation unit)
46 Display unit 50 Photometric device 61 Concave mirror 62 Convex mirror L Perimeter R2 Internal region S Test object Sa Measurement surface

Claims (7)

A photometric device comprising: a light source; an objective optical system that guides a measurement light beam emitted from the light source to a test object; and a photometry unit that measures a reflected light beam reflected by the measurement surface of the test object. There,
An alignment state confirmation unit that is disposed on the optical path of the reflected light beam and has an imaging unit that captures an image of the reflected light beam at a position different from the focal point of the reflected light beam;
A display unit for displaying information obtained from the image of the reflected light beam imaged by the imaging unit;
A photometric device comprising:   The photometry device according to claim 1, wherein the alignment state confirmation unit includes a collimator lens, and the reflected light beam is imaged by the imaging unit after being converted into parallel light.   The alignment state confirmation unit includes a calculation unit that calculates an alignment amount indicating an alignment state of the test object based on an image of the reflected light beam captured by the imaging unit. The photometric device described.   The photometric device according to claim 3, wherein the objective optical system is configured by arranging a concave mirror and a convex mirror with their mirror surfaces facing each other.   5. The photometric device according to claim 4, wherein the calculation unit calculates a position of the center of gravity of an internal region of the reflected light flux image having an annular shape as the alignment amount.   5. The photometric device according to claim 4, wherein the calculation unit calculates an area of an inner region of the image of the reflected light beam having an annular shape as the alignment amount.   5. The photometric device according to claim 4, wherein the calculation unit calculates a ratio between an area in an inner region of an image of the reflected light beam having an annular shape and a peripheral length as the alignment amount.

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