JP5217046B2 - Optical characteristic measuring apparatus and optical characteristic measuring method - Google Patents

Description

  The present invention relates to an optical property measuring apparatus and an optical property measuring method, and more particularly, to an optical property measuring apparatus that measures the optical property of a measurement object by irradiating the measurement object with light and measuring the reflected light, and the apparatus. The present invention relates to a method for measuring optical characteristics used.

  2. Description of the Related Art Conventionally, an optical characteristic measuring apparatus that measures optical characteristics of an object to be measured by irradiating the object to be measured and spectrally measuring the reflected light is known. Examples of such an optical characteristic measuring apparatus include those described in JP-A-11-316186 (Patent Document 1) and JP-A-11-230829 (Patent Document 2).

  The optical characteristic measurement apparatus (spectrophotometer) described in Patent Document 1 has an openable / closable upper light-shielding portion for shielding light from a sample set surface on which an object to be measured is placed.

  An optical characteristic measuring device (microspectroscopic device) described in Patent Document 2 includes an illumination optical system that guides illumination light emitted from a light source to a measurement sample placed on a table via a half mirror, and a measurement sample. And an imaging optical system that guides the light reflected at the diffraction grating and a monitoring optical system. The diffraction grating functions as a spectroscopic unit that splits observation light from the measurement region on the measurement sample, and forms an image of the spectral spectrum on the line sensor. Then, the optical characteristics are calculated from the spectral spectrum measured by the line sensor. On the other hand, the monitor optical system forms an enlarged image of the measurement sample on a two-dimensional CCD camera using a relay lens. The enlarged image of the measurement sample picked up by the CCD camera is used for confirmation of the measurement position and rough focusing.

In a general optical characteristic measuring apparatus, like the microspectroscopic apparatus described in Patent Document 2, illumination light emitted from a light source is used for both spectral spectrum measurement and focusing.
Japanese Patent Laid-Open No. 11-316186 Japanese Patent Application Laid-Open No. 11-230829

  In the optical characteristic measuring apparatus as described in Patent Documents 1 and 2, there is a demand for focusing the objective lens facing the object to be measured and specifying the measurement site. On the other hand, in the optical characteristic measuring apparatus described in Patent Document 2, by providing the CCD camera (16), focusing and characteristics of the measurement site are possible. However, as described above, the illumination emitted from the light source Since light is used for both spectral spectrum measurement and focusing, it is inevitably necessary to insert observation illumination into the optical path of the spectral measurement light using the half mirror (13). For this reason, there exists a problem that the light quantity of measurement light is impaired.

  The present invention has been made in view of the above problems, and an object of the present invention is an optical characteristic capable of adjusting the focus of an objective lens and specifying a measurement site while suppressing a reduction in measurement light quantity. An object of the present invention is to provide a measuring apparatus and an optical property measuring method.

An optical property measurement apparatus according to the present invention includes a measurement unit that measures optical properties of a measurement object by spectroscopically spreading linear measurement light from the measurement object so as to be spread on a plane, the measurement object, and the measurement unit Observation light including a wavelength that can be reflected by the object to be measured can be injected from outside the optical path to a predetermined position on the optical path between the objective lens provided on the optical path between the measurement unit and the objective lens. A first mode in which observation light is injected into the optical path, and a second mode in which measurement by the measurement unit is performed without injecting observation light into the optical path.

  According to the above configuration, the focus adjustment of the objective lens and the specification of the measurement site are performed by injecting observation light including a wavelength that can be reflected by the measurement object into the optical path between the measurement object and the measurement unit. Is possible. Here, by performing measurement by the measurement unit without injecting observation light, the optical path can be opened when performing measurement. Therefore, according to the optical characteristic measuring apparatus of the present invention, it is possible to adjust the focus of the objective lens and specify the measurement site while suppressing the reduction of the measurement light quantity. Furthermore, since observation light is suppressed from entering the measurement optical system, stray light is suppressed from being generated during measurement.

Upper Symbol optical characteristic measuring apparatus further includes a shutter provided at the predetermined position of the optical path, the shutter is opened and the first state to direct observation light while closing the optical path to the objective lens, the optical path The second state can be realized, and the first mode is realized when the shutter is in the first state, and the second mode is realized when the shutter is in the second state.

  As described above, the first mode and the second mode can be realized with a simple configuration by providing the shutter capable of switching between closing and opening of the optical path.

Upper Symbol optical characteristic measuring apparatus is provided between the objective lens and the shutter further includes a mirror unit for reflecting the measuring light, and an imaging unit for obtaining a reflection image obtained by the reflected light from the mirror portion.

  As described above, it is possible to adjust the focus of the objective lens and specify the measurement site based on the image obtained by the imaging unit by providing the imaging unit that acquires the reflection image obtained by the reflected light of the measurement light. Become.

An optical characteristic measurement method according to the present invention is an optical characteristic measurement method for measuring optical characteristics of a measurement object by performing spectroscopic analysis so that a linear measurement light from the measurement object is spread on a plane. The optical path of the measurement light is closed by a shutter provided at a predetermined position on the opposite side of the object to be measured with respect to the objective lens, and can be reflected by the object to be measured toward the predetermined position. A first step of injecting observation light including an appropriate wavelength from outside the optical path, and a second step of performing measurement using the measurement light without injecting observation light into the optical path while the shutter opens the optical path. Prepare.

  According to the above method, in the first step, the observation light including the wavelength that can be reflected by the object to be measured is injected into the optical path between the object to be measured and the measurement unit, thereby adjusting the focus of the objective lens and the measurement site. Can be specified. Furthermore, in the second step, the optical path can be opened when performing measurement by performing measurement by the measurement unit without injecting observation light. Therefore, according to the optical characteristic measuring method according to the present invention, it is possible to adjust the focus of the objective lens and specify the measurement site while suppressing the reduction of the measurement light quantity. Furthermore, since observation light is suppressed from entering the measurement optical system, stray light is suppressed from being generated during measurement.

Upper Symbol optical characteristic measuring method includes reflects the measurement light by the mirror portion provided on the optical path, to obtain a reflected image obtained by the reflected light from the mirror portion.

  As described above, by acquiring a reflected image obtained by the reflected light from the mirror section provided on the optical path, it is possible to adjust the focus of the objective lens and specify the measurement site based on the reflected image. It becomes.

  ADVANTAGE OF THE INVENTION According to this invention, the focus adjustment of an objective lens and specification of a measurement site | part can be performed, suppressing the reduction of the light quantity of the measurement light for measuring an optical characteristic.

  Embodiments of the present invention will be described below. Note that the same or corresponding portions are denoted by the same reference numerals, and the description thereof may not be repeated.

  Note that in the embodiments described below, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, and the like unless otherwise specified. In the following embodiments, each component is not necessarily essential for the present invention unless otherwise specified. In addition, when there are a plurality of embodiments below, it is planned from the beginning to appropriately combine the configurations of the embodiments unless otherwise specified.

  The optical property measurement apparatus according to the present embodiment is typically used for applications such as color unevenness measurement, luminance unevenness measurement, film thickness unevenness measurement, and multipoint spectroscopic measurement, but is applied to other applications. Is also possible.

  FIG. 1 is a diagram for explaining a usage state of an optical characteristic measuring apparatus according to one embodiment of the present invention. Referring to FIG. 1, a spectrometer 1 as an optical characteristic measuring apparatus according to the present embodiment is an apparatus for measuring optical characteristics of a sample 2 </ b> A that is an object to be measured. As shown in FIG. 1, the spectrometer 1 can measure a linear area. That is, the spectroscope 1 analyzes the optical characteristics of the sample 2A by dispersing the linear light so as to be developed on a plane. By doing in this way, it is possible to measure the optical characteristics of the object to be measured having a planar spread in a relatively short time.

  In the example of FIG. 1, the rectangular sample 2A is slid in the direction of the arrow DR2A, and measurement is performed by a plurality of (for example, three) spectrometers 1 arranged in the width direction of the sample 2A. Measurement of the optical characteristics.

On the other hand, a modified example as shown in FIG. In the example of FIG. 2, the optical characteristics of the sample 2B are measured by measuring with one spectroscope 1 while rotating the circular sample 2B in the direction of the arrow DR2B.
<Configuration of spectrometer 1>
Next, the configuration of the spectrometer 1 will be described with reference to FIG. Referring to FIG. 3, spectrometer 1 includes measurement unit 10, objective lens 20, LED 30, slit mirror 40, shutter 50, triplet lenses 60 and 80, diffraction grating 70, and mirrors 90 and 100. A lens 110, an imaging unit 120, and a housing 130.

  The measurement unit 10 includes a light receiving unit 11. When the spectroscope 1 measures the optical characteristics of the object 2 to be measured, the object 2 is irradiated with light from a measurement light source (not shown), and the reflected light from the object 2 is reflected on the diffraction grating 70. To the light receiving unit 11 in the measurement unit 10.

  The objective lens 20 is provided so as to face the object to be measured 2. Light from a measurement light source (not shown) reaches the measurement object 2 via the objective lens 20, and reflected light (measurement light) reflected by the measurement object 2 reaches the measurement unit 10 via the objective lens 20.

  The LED 30 is a light source that emits light (observation light) for focusing on the object to be measured 2 and specifying a measurement target position on the object to be measured 2. The LED 30 emits observation light toward the shutter 50. The shutter 50 reflects light from the LED 30 toward the objective lens 20 in the closed state. Since this reflected light is imaged on the surface of the object 2 to be measured, it is possible to adjust the focus of the objective lens 20 by adjusting the objective lens 20 so that the focal point thereof is in focus. It is also possible to specify the measurement site from the position of the light imaged on the surface of the DUT 2.

  The slit mirror 40 is a mirror member having an elongated opening (slit). The linear light that has passed through the slit mirror 40 is guided to the light receiving unit 11 of the measuring unit 10 through the triplet lens 60, the diffraction grating 70, and the triplet lens 80 when the shutter 50 is open. On the other hand, the light reflected by the slit mirror 40 is guided to the imaging unit 120 via the mirrors 90 and 100 and the lens 110. By doing in this way, the image around the measuring unit reflected on the mirror unit of the slit mirror 40 can be acquired by the imaging unit 120. In the imaging unit 120, an image in which only the slit portion of the slit mirror 40 is shown in black is obtained. Therefore, among the images obtained in the imaging unit 120, the slit portion formed in black is the measurement site. That is, it is possible to specify the measurement site by referring to the image obtained by the imaging unit 120. Moreover, the focus adjustment of the objective lens 20 can be performed by adjusting the objective lens 20 so that the image reflected on the slit mirror 40 is in focus.

Note that the above-described LED 30, slit mirror 40, shutter 50, triplet lenses 60 and 80, diffraction grating 70, mirrors 90 and 100, and lens 110 are all housed in a single housing 130. The spectroscope 1 is configured by attaching the measurement unit 10, the objective lens 20, and the imaging unit 120 to the housing 130. A control device 3 is connected to the measurement unit 10 of the spectrometer 1. The control device 3 calculates the optical characteristics of the DUT 2 from the detection result by the spectroscope 1. An example of a method for calculating this optical characteristic will be described later.
<Procedure for Optical Characteristic Measurement with Spectrometer 1>
Next, the procedure of measuring optical characteristics by the spectrometer 1 will be described with reference to FIG. Referring to FIG. 4, the optical characteristic measurement method by the spectroscope 1 includes a step of injecting observation light from the LED 30 (S <b> 10 in FIG. 4), and a measurement light source (injection of observation light from the LED 30). (Step S20 in FIG. 4) performing measurement using measurement light from (not shown).

  In S10, the shutter 50 is in the “closed state”. In this state, the light from the LED 30 is reflected toward the device under test 2. Here, it is possible to adjust the focus of the objective lens 20 by adjusting the objective lens 20 so that the image to be determined on the surface of the DUT 2 is in focus. Further, it is possible to specify the measurement site from the position of the light imaged on the surface of the DUT 2.

  On the other hand, an image of light reflected by the DUT 2 is acquired by the imaging unit 120. By referring to the image obtained by the imaging unit 120, the measurement site can be specified. Further, it is possible to adjust the focus of the objective lens 20 by adjusting the objective lens 20 so that the image reflected on the slit mirror 40 is in focus.

After S10, in S20, the optical characteristic of the DUT 2 is measured using light from a light source (measurement light source) different from the LED 30. In S20, the LED 30 is turned off. By doing in this way, since it suppresses that the light from LED30 enters a measurement optical system, it is suppressed that stray light arises during a measurement.
<Method of calculating optical characteristics based on detection result of spectrometer 1>
Next, a method for calculating optical characteristics based on the detection result of the spectrometer 1 will be described. As shown in FIG. 3, the control device 3 is connected to the measurement unit 10 of the spectrometer 1. The control device 3 calculates optical characteristics such as the brightness and chromaticity of the DUT 2 based on the measurement values obtained by the spectrometer 1. Typical examples of the optical characteristics calculated by the control device 3 include tristimulus values, chromaticity coordinates, dominant wavelength (Dominant), stimulus purity (Purity), correlated color temperature and deviation Duv, and color rendering index. . These measurement items are mainly defined based on the XYZ color system.

  The XYZ color system is defined using tristimulus values (X, Y, Z) calculated according to the following arithmetic expression.

  As shown in the above equation, measurement values (spectral distribution) are necessary for calculating the tristimulus values (X, Y, Z), and the control device 3 determines the intensity of each wavelength component in the visible region (380 nm to 780 nm). Are multiplied by the values of the color matching functions corresponding to. The calculation method of the tristimulus values (X, Y, Z) is defined as JIS Z 8724 “Color measurement method—Light source color”.

  FIG. 5 is a diagram showing color matching functions defined by the International Commission on Illumination (CIE). Referring to FIG. 5, the color matching function corresponds to a representation of spectral sensitivity in the human eye.

  Of the tristimulus values (X, Y, Z), the value of the stimulus value Y is a value corresponding to the brightness of the DUT 2. In the above equation, the constant k is a value that considers the detection gain in the light receiving unit 330 and the like, and is set in advance so that the value of “Y” matches the absolute value of the actually measured brightness.

  Of the tristimulus values (X, Y, Z), the stimulus value X and the stimulus value Y are used for calculating chromaticity coordinates. The chromaticity coordinates (x, y) are calculated according to the following arithmetic expression.

  The chromaticity coordinates (x, y) indicate a value in the horizontal axis direction and a value in the vertical axis direction of the XYZ color system. The calculation method of the chromaticity coordinates (x, y) is defined as JIS Z 8724 “Color measurement method—light source color”. As the calculation method of the chromaticity coordinates, another calculation method is also defined by CIE 1960 UCS and CIE 1976 UCS, and these calculation methods may be used.

  As described above, the control device 3 calculates the tristimulus values (X, Y, Z) based on the measurement values detected by the spectroscope 300, so that the brightness (kY) of the measurement target object 2 is measured. ) And chromaticity coordinates (x, y). The control device 3 stores the color matching function and the constant k described above in advance.

  The dominant wavelength corresponds to the wavelength corresponding to the value of the y coordinate of the chromaticity coordinates (x, y) in the chromaticity diagram defined in the XYZ color system, and means the color difference of the DUT 2. . The stimulus purity corresponds to the distance between the coordinates of the origin and the chromaticity coordinates (x, y), and means the color density of the DUT 2. The calculation method of the dominant wavelength and stimulation purity is defined as JIS Z 8701 “Color Display Method—XYZ Color System and X10Y10Z10 Color System”.

  The correlated color temperature and the deviation Duv mean the deviation of the temperature of the black body and the temperature of the black body that are closest to the color of the object 2 to be measured, respectively. JIS Z 8725 “Light source distribution temperature and color temperature / correlated color temperature "Measurement method".

The color rendering index is for evaluating the color rendering of the DUT 2 and is defined as JIS Z 8726 “Color rendering evaluation method of light source”.
<Modification of the above configuration>
As modifications of the above configuration, for example, the following can be considered. That is, in this modification, the lens 110 and the imaging unit 120 in FIG. 3 are eliminated, and other LEDs are provided in accordance with the centers of their optical axes. In this case, light (observation light) from other LEDs is reflected by the slit mirror 40 and reaches the surface of the DUT 2. Here, the objective lens 2 can be focused by adjusting the objective lens 2 so as to focus on the DUT 2. Further, in the image formed on the surface of the DUT 2, the position corresponding to the slit portion is the measurement position.
<Summary>
The above contents are summarized as follows. That is, the spectroscope 1 as the “optical characteristic measuring device” according to the present embodiment includes a measuring unit 10 that measures the optical characteristics of the DUT 2 using the measurement light from the DUT 2, and the DUT. 2 and the objective lens 20 provided on the optical path between the measuring unit 10 and a wavelength that can be reflected by the DUT 2 at a predetermined position on the optical path between the measuring unit 10 and the objective lens 20. And an LED 30 as a “light injection part” capable of injecting observation light from outside the optical path. The spectroscope 1 has a first mode (S10 in FIG. 4) for injecting observation light into the optical path, and a second mode (in FIG. 4) for performing measurement by the measurement unit 10 without injecting observation light into the optical path. S20) can be realized.

  More specifically, the spectroscope 1 further includes a shutter 50 provided at the predetermined position in the optical path. The shutter 50 can realize a first state in which the observation light is directed toward the objective lens 20 while closing the optical path, and a second state in which the optical path is opened. The shutter 50 is in a first state (closed state). Thus, the first mode (S10) is realized, and the second mode (S20) is realized when the shutter 50 is in the second state (open state).

  The spectroscope 1 is provided between the objective lens 20 and the shutter 50, and acquires a reflection image obtained by the slit mirror 40 as a “mirror part” that reflects the measurement light and the reflected light from the slit mirror 40. And an imaging unit 120.

  According to the spectrometer 1 according to the present embodiment, by injecting observation light including a wavelength that can be reflected by the object to be measured 2 into the optical path between the object to be measured 2 and the measurement unit 10, It is possible to adjust the focus and specify the measurement site. Here, by performing measurement by the measurement unit 10 without injecting observation light, the optical path can be opened when performing measurement. Therefore, according to the spectroscope 1, it is possible to adjust the focus of the objective lens 20 and specify the measurement site while suppressing the reduction of the measurement light quantity.

  Furthermore, the spectroscope 1 can realize the first mode (S10) and the second mode (S20) with a simple configuration by providing the shutter 50 capable of switching between closing and opening of the optical path.

  Further, the spectroscope 1 is provided with an imaging unit 120 that acquires a reflected image obtained by the reflected light of the measurement light, thereby adjusting the focus of the objective lens 20 and specifying the measurement site based on the image obtained by the imaging unit 120. It is also possible to do this.

  The optical property measuring method according to the present embodiment is an optical property measuring method for measuring the optical property of the object 2 to be measured using the measurement light from the object 2 to be measured on the optical path of the measuring light. A first step (S10) of injecting observation light including a wavelength that can be reflected by the object to be measured 2 from a position outside the optical path to a predetermined position located on the opposite side of the object to be measured with respect to the lens 20; And a second step (S20) for performing measurement using the measurement light without injecting into the path. It is also possible to reflect the measurement light with the slit mirror 40 provided on the optical path and obtain a reflected image obtained by the reflected light from the slit mirror 40.

  Although the embodiments of the present invention have been described above, the embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows an example of the use condition of the optical characteristic measuring apparatus which concerns on one embodiment of this invention. It is a figure which shows the other example of the use condition of the optical characteristic measuring apparatus which concerns on one embodiment of this invention. It is a figure which shows the structure of the optical characteristic measuring apparatus which concerns on one embodiment of this invention. It is a flowchart explaining the optical characteristic measuring method which concerns on one embodiment of this invention. It is a figure which shows the color matching function defined by the international lighting commission (CIE).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Spectrometer, 2 to-be-measured object, 2A, 2B sample, 3 Control apparatus, 10 Measurement part, 11 Light-receiving part, 20 Objective lens, 30 LED, 40 Slit mirror, 50 Shutter, 60 Triplet lens, 70 Diffraction grating, 80 Triplet Lens, 90, 100 mirror, 110 lens, 120 imaging unit, 130 housing.

Claims (2)

A measuring unit that measures the optical characteristics of the object to be measured by spectroscopically spreading the linear measuring light from the object to be measured on a plane ; and
An objective lens provided on an optical path between the object to be measured and the measurement unit;
A light injection unit capable of injecting observation light including a wavelength that can be reflected by the object to be measured from outside the optical path at a predetermined position on the optical path between the measurement unit and the objective lens ;
A shutter provided at the predetermined position of the optical path;
A mirror part provided between the objective lens and the shutter and reflecting the measurement light;
An imaging unit that acquires a reflected image obtained by reflected light from the mirror unit,
It is possible to realize a first mode in which the observation light is injected into the optical path and a second mode in which measurement is performed by the measurement unit without injecting the observation light into the optical path .
The shutter can realize a first state in which the observation light is directed toward the objective lens while closing the optical path, and a second state in which the optical path is opened.
The optical characteristic measuring device , wherein the first mode is realized when the shutter is in the first state, and the second mode is realized when the shutter is in the second state . An optical property measurement method for measuring optical properties of the object to be measured by spectroscopically spreading linear measurement light from the object to be measured on a plane ,
On the optical path of the measurement light, the optical path of the measurement light is closed by a shutter provided at a predetermined position on the opposite side of the object to be measured with respect to the objective lens, and toward the predetermined position, A first step of injecting observation light including a wavelength that can be reflected by the object to be measured from outside the optical path;
A second step in which the shutter opens the optical path and performs measurement using the measurement light without injecting the observation light into the optical path ;
An optical property measurement method , comprising: reflecting the measurement light by a mirror unit provided on the optical path to obtain a reflected image obtained by the reflected light from the mirror unit .

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