Spectrophotometer

Abstract

The invention provides a spectrophotometer which can irradiate observation light to a measured position without setting a large space in the spectrophotometer and can easily know the measured position. In a spectrophotometer, a slit is disposed at a position optically conjugated to a position to be measured. Light from an object to be measured passes through a slit, travels on a measurement light path, and is wavelength-dispersed by a wavelength dispersion element. When the spectrum is measured, the observation light source is withdrawn to the outside of the measurement light path. When the measured position is observed, the observation light source is inserted into the measurement light path and emits observation light to the slit. Alternatively, the light from the measured object passes through the slit and is diffracted by the diffraction grating. The observation light source is disposed on the optical path of the 0-order light. When the measured position is observed, the observation light source emits observation light to the diffraction grating.

Description

[0001] This application is a divisional application of the invention patent application with the application date of April 24, 2018, application number 201880035080.0, and invention name “Spectrophotometer”. Technical Field

[0002] The present invention relates to a spectrophotometer. Background Art

[0003] When a spectrophotometer, used to measure spectra, has a very small measurable range, even when the measured position is only slightly offset from the target position, there can be significant differences between the measured spectrum and the spectrum of light originating from the target position. Therefore, when a spectrophotometer has a very small measurable range, it is desirable to observe the measured position before measurement and to align the measured position with the target position. The technology described in Patent Document 1 is an example of a technology that can achieve this goal in a spectrometer.

[0004] In the technology described in Patent Document 1, when observation light is injected, the shutter is closed. Then, an LED illuminates the shutter, which reflects the observation light toward the objective lens, which then forms an image on the surface of the object being measured. The measurement location is determined based on the position of the light image formed on the surface of the object being measured. Furthermore, when measuring, the shutter is opened, and light that has passed through the slit mirror is guided to the light receiving unit (paragraphs 0027-0031).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2009-288150 Summary of the Invention

[0008] Technical problem to be solved by the invention

[0009] In the prior art represented by the technology described in Patent Document 1, a relatively large space must be provided within the spectrophotometer in order to accommodate the mechanism for irradiating the measurement position with observation light. For example, in the technology described in Patent Document 1, a relatively large space must be provided within the spectrophotometer in order to accommodate a slit mirror and other components within the spectrophotometer.

[0010] The invention described below aims to solve this problem. The technical problem to be solved by the invention described below is to illuminate the measured position with observation light without providing a large space inside the spectrophotometer, thereby making it possible to easily know the measured position.

[0011] Technical solutions to technical problems

[0012] A spectrophotometer having:

[0013] an illumination optical system comprising an illumination light source and an integrating sphere having a measurement opening, and illuminating a sample arranged opposite the measurement opening with diffuse light diffused by the integrating sphere;

[0014] a light receiving optical system for imaging the light to be measured incident from the position to be measured through the measurement opening to generate imaged light to be measured;

[0015] a slit forming body disposed at an image forming position of the light receiving optical system and having a slit formed therein for allowing the light to be measured to pass therethrough to generate the light to be measured that travels on a measurement optical path;

[0016] a wavelength dispersion element for performing wavelength dispersion on the light to be measured traveling along the measurement optical path to generate wavelength dispersed light to be measured;

[0017] a sensor having a plurality of photoelectric conversion elements arranged in a wavelength dispersion direction, receiving the wavelength-dispersed light to be measured and outputting a signal representing a spectrum;

[0018] an observation light source configured to irradiate the slit with light from the wavelength dispersion element side and emit observation light, the observation light forming an image of the slit formed by the light receiving optical system at the measured position of the sample;

[0019] a target mask that blocks external light in such a manner that the gap between the integrating sphere and the sample is not entered;

[0020] an auxiliary light source that emits light simultaneously with the observation light from the observation light source and emits auxiliary illumination light that illuminates an area other than the measured position in a recognizable manner;

[0021] A detector is used to observe the measured position.

[0022] The invention described below relates to a spectrophotometer.

[0023] (1) In the first invention described below, the light to be measured from the position to be measured is imaged by the light receiving optical system, thereby generating imaged light to be measured.

[0024] The imaged light to be measured passes through a slit arranged at a position conjugate to the position to be measured, thereby generating light to be measured that travels on a measurement optical path.

[0025] The light to be measured traveling along the measurement optical path is wavelength-dispersed by the wavelength dispersion element, thereby generating wavelength-dispersed light.

[0026] The sensor receives wavelength-dispersed light and outputs a signal representing the spectrum.

[0027] The insertion and extraction mechanism inserts the observation light source into the measurement optical path when observing the measured position, and withdraws the observation light source from the measurement optical path when measuring the spectrum.

[0028] The observation light source emits observation light toward the slit when observing the measured position.

[0029] (2) In the second invention described below, the light to be measured from the position to be measured is imaged by the light receiving optical system, thereby generating imaged light to be measured.

[0030] The imaged light to be measured passes through the slit, thereby generating the light to be measured that travels on the measurement light path.

[0031] The light to be measured traveling along the measurement optical path is diffracted by the diffraction grating, thereby generating diffracted light. Furthermore, the light to be measured traveling along the measurement optical path is reflected by the diffraction grating, thereby generating zero-order light.

[0032] The sensor receives the diffracted light and outputs a signal representing the spectrum.

[0033] The observation light source is arranged on the optical path of the 0th-order light, and emits observation light toward the diffraction grating when observing the measured position.

[0034] Effects of the Invention

[0035] According to the invention described below, it is possible to irradiate the position to be measured with observation light without providing a large space inside the spectrophotometer, and to easily know the position to be measured.

[0036] The objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram illustrating the spectrophotometer according to the first embodiment.

[0038] Figure 2 It is a schematic diagram illustrating a cross section of a spectrometer included in the spectrophotometer according to the first embodiment.

[0039] Figure 3 It is a schematic diagram showing a partial cross section of a drive mechanism for a spectrometer and an observation light source included in the spectrophotometer according to the first embodiment.

[0040] Figure 4 This is a schematic diagram illustrating an observation light source that can replace the observation light source included in the spectrophotometer of the first embodiment.

[0041] Figure 5Schematic diagram illustrating a spectrophotometer according to a second embodiment.

[0042] Figure 6 It is a perspective view illustrating the arrangement of a diffraction grating of a spectrophotometer according to a second embodiment.

[0043] Figure 7 It is a perspective view showing the arrangement of the diffraction grating in comparison with the arrangement of the diffraction grating of the spectrophotometer according to the second embodiment. DETAILED DESCRIPTION

[0044] 1. First Implementation

[0045] 1.1 Spectrophotometer

[0046] Figure 1 Schematic diagram illustrating the spectrophotometer according to the first embodiment. Figure 2 It is a schematic diagram illustrating a cross section of a spectrometer included in the spectrophotometer according to the first embodiment. Figure 3 It is a schematic diagram showing a partial cross section of a drive mechanism for a spectrometer and an observation light source included in the spectrophotometer according to the first embodiment.

[0047] Figure 2 right Figure 3 The cross section of the position of the AA cutting line is illustrated. Figure 3 right Figure 2 A partial cross-section of the BB cutting line is shown.

[0048] Figure 1 The illustrated spectrophotometer 1000 includes an illumination optical system 1020, a light receiving optical system 1021, a spectrometer 1022, a controller 1023, and an operation unit 1024. The spectrophotometer 1000 may include components other than the components described above.

[0049] Spectrophotometer 1000 is a spectrophotometer for object color with d:8 geometry. Therefore, in spectrophotometer 1000, illumination system 1020 illuminates the sample with diffuse light. Furthermore, light-receiving system 1021 receives the measured light emitted from the sample in a direction that forms an 8° angle with respect to the normal to the sample surface and guides it toward spectrometer 1022. Furthermore, spectrometer 1022 measures the spectrum of the measured light guided by light-receiving system 1021.

[0050] The illumination optical system 1020 includes an illumination light source 1040 and an integrating sphere 1041. The illumination optical system 1020 may also include components other than the above components. The light receiving optical system 1021 includes a light receiving lens 1060. The light receiving optical system 1021 may also include components other than the light receiving lens 1060. Figure 1 、 Figure 2 and Figure 3 As shown, the spectrometer 1022 includes a slit plate 1080, a lens 1081, a diffraction grating 1082, a line sensor 1083, an observation light source 1084, and an insertion and removal mechanism 1085. The spectrometer 1022 may also include components other than those described above. A slit 1100 is formed in the slit plate 1080. The plate-shaped slit-forming member, i.e., the slit plate 1080, may be replaced with a non-plate-shaped slit-forming member. The diffraction grating 1082 may be replaced with a wavelength dispersion element other than the diffraction grating 1082. For example, the diffraction grating 1082 may be replaced with a prism. The line sensor 1083, which includes multiple photoelectric conversion elements arranged in the wavelength dispersion direction, may be replaced with a sensor other than the line sensor 1083. For example, the line sensor 1083 may be replaced with a sensor having a single photoelectric conversion element. In this case, a scanning mechanism is provided to scan the sensor in the wavelength dispersion direction. Alternatively, a scanning mechanism is provided for rotating and scanning the wavelength dispersion element in the wavelength dispersion direction.

[0051] 1.2 Spectral measurement

[0052] Spectral measurement is started in response to the controller 1023 detecting an operation instructing the start of measurement performed on the operating unit 1024. The measurement start trigger may be an operation other than the operation instructing the start of measurement performed on the operating unit 1024. For example, the measurement start trigger may be a signal instructing the start of measurement input from a device communicably connected to the spectrophotometer 1000.

[0053] During spectrum measurement, the insertion and removal mechanism 1085 retracts the observation light source 1084 from the measurement optical path 1120 under control of the controller 1023. The observation light source 1084 is retracted by the rotation mechanism 1090 rotating the arm 1091 to which the observation light source 1084 is attached around the rotation center 1092.

[0054] In addition, when measuring the spectrum, the illumination light source 1040 emits illumination light for illuminating the sample according to the control by the controller 1023 .

[0055] The emitted illumination light enters the space 1160 formed inside the integrating sphere 1041 through the opening 1140 formed in the side surface of the integrating sphere 1041, and is diffusely reflected multiple times by the diffuse reflection surface 1180 surrounding the space 1160. Thus, the illumination light becomes uniform diffuse illumination light.

[0056] The uniform diffuse illumination light is emitted from the measurement aperture 1200 formed in the integrating sphere 1041, illuminates the area facing the measurement aperture 1200, and is reflected by the surface of the sample arranged at the measurement position 1220. Thus, the measurement light 1240 from the measurement position 1220 is generated.

[0057] When performing measurement without regular reflection light, the regular reflection light is removed by opening the openable and closable well 1260 formed in the integrating sphere 1041 .

[0058] The generated measured light 1240 is imaged at the slit 1100 by the light receiving lens 1060. This generates imaged measured light 1280. The light receiving lens 1060 is movable along its optical axis. By moving the light receiving lens 1060 along its optical axis, the size of the measured area can be changed.

[0059] The imaged light 1280 to be measured passes through the slit 1100 , thereby generating light 1300 to be measured that travels along the measurement optical path 1120 between the slit 1100 and the diffraction grating 1082 .

[0060] The measured light 1300 traveling along the measurement optical path 1120 is guided by the lens 1081 and diffracted by the diffraction grating 1082. This generates diffracted light including -1st-order diffracted light 1320. Since the measured light 1300 traveling along the measurement optical path 1120 is wavelength-dispersed by diffraction, the -1st-order diffracted light 1320 is wavelength-dispersed.

[0061] The generated −1st-order diffracted light 1320 is received by the line sensor 1083 . The line sensor 1083 may also receive diffracted light other than the −1st-order diffracted light 1320 .

[0062] The line sensor 1083 outputs a signal indicating a spectrum corresponding to the received −1st-order diffracted light 1320 .

[0063] 1.3 Observation of the measured position

[0064] The spectrophotometer 1000 has a function of irradiating the measurement position 1220 with observation light. The operator of the spectrophotometer 1000 can observe the measurement position 1220 by recognizing the bright portion generated by irradiating the measurement position 1220 with observation light through the detector hole 1340 formed in the integrating sphere 1041.

[0065] When observing the measured position 1220, the insertion and extraction mechanism 1085 inserts the observation light source 1084 into the measurement optical path 1120 under control of the controller 1023. The insertion of the observation light source 1084 is performed by rotating the arm 1091, to which the observation light source 1084 is mounted, around a rotation center 1092 by the rotation mechanism 1090. When the observation light source 1084 is inserted into the measurement optical path 1120, the light emitting surface of the observation light source 1084 faces the slit 1100, and the observation light source 1084 can emit observation light toward the slit 1100.

[0066] When observing the measured position 1220 , the observation light source 1084 emits observation light toward the slit 1100 in accordance with control by the controller 1023 .

[0067] The emitted observation light passes through the slit 1100 and is imaged by the light receiving lens 1060 .

[0068] Slit 1100 is positioned optically conjugate with measured position 1220. Therefore, when observation light source 1084 emits observation light, an image of slit 1100 is formed on the sample surface. Because the image of slit 1100 is formed at measured position 1220, the operator can observe measured position 1220 by viewing the image of slit 1100 through detector aperture 1340 formed in integrating sphere 1041.

[0069] The slit 1100 is optically conjugate with the measured position 1220, which helps prevent the position of the image of the slit 1100 from shifting even if the position of the observation light source 1084 is shifted. Furthermore, by inserting the observation light source 1084 into the measurement optical path 1120 using the insertion and removal mechanism 1085, the observation light source 1084 can be positioned near the slit 1100, thereby increasing the amount of observation light available for use as indicator light.

[0070] According to the spectrophotometer 1000 of the first embodiment, it is not necessary to provide a large space, such as between the slit 1100 and the diffraction grating 1082, inside the spectrophotometer 1000. Observation light serving as indicator light can be irradiated onto the measured position 1220, making it easy to observe the measured position 1220. Furthermore, according to the spectrophotometer 1000 of the first embodiment, it is also unnecessary to add a component such as a reflecting mirror.

[0071] 1.4 Observation Light Source

[0072] The observation light source 1084 includes a light-emitting diode (LED) that emits observation light. The LED is preferably a thin LED. While light sources other than LEDs can be used to emit the observation light, using an LED to emit the observation light allows for a more compact spectrophotometer 1000. Furthermore, using an LED to emit the observation light reduces power consumption of the observation light source 1084, extending its lifespan.

[0073] Figure 4 This is a schematic diagram illustrating an observation light source that can replace the observation light source included in the spectrophotometer of the first embodiment.

[0074] Figure 4 The illustrated observation light source 1380 can be replaced Figure 1 The illustrated observation light source 1084 includes LEDs 1400, 1401, and 1402. LEDs 1400, 1401, and 1402 each emit light 1420, 1421, and 1422. Light 1420, 1421, and 1422 have different colors. The three LEDs formed by LEDs 1400, 1401, and 1402 can be replaced with two or more LEDs. At least some of LEDs 1400, 1401, and 1402 can also be replaced with a light source other than LEDs.

[0075] When observation light source 1084 is replaced with observation light source 1380, controller 1023 and operating unit 1024 function as a switching mechanism for switching between the light sources 1420, 1421, and 1422 used as observation light. Specifically, controller 1023 controls LEDs 1400, 1401, and 1402 to detect a color selection operation performed on operating unit 1024, causing observation light source 1380 to emit light corresponding to the selected color. This allows the color of the observation light to be selected based on the color of the sample surface, making it easier to observe measurement location 1220. Alternatively, the sample color can be temporarily measured while observing measurement location 1220, and the results of the temporary measurement can be used to determine the color of the light emitted by observation light source 1380.

[0076] 1.5 Observing the illumination light when measuring the position

[0077] In object color spectrophotometer 1000, to prevent external light other than the illumination light from entering the gap between illumination optical system 1020 and the sample, this gap is often blocked by a target mask or the like. Furthermore, when this gap is blocked, observation light only illuminates measurement location 1220, making it difficult to identify portions outside measurement location 1220, and thus, unable to determine which portion of the sample surface measurement location 1220 is. Therefore, illumination light source 1040 can be used as an auxiliary light source when observing measurement location 1220. During observation of measurement location 1220, illumination light source 1040 emits illumination light under control of controller 1023. This allows for identification of portions outside measurement location 1220 and for determination of which portion of the sample surface measurement location 1220 is located.

[0078] When illuminating light while observing the measured position 1220, the controller 1023 and the operating unit 1024 function as an adjustment mechanism for adjusting the light intensity of the illumination light. Specifically, the controller 1023 controls the illumination light source 1040 to detect an operation performed on the operating unit 1024 to set the light intensity of the illumination light, and causes the illumination light source 1040 to emit illumination light having an intensity corresponding to the selected light intensity.

[0079] 1.6 Others

[0080] The above-described configuration for irradiating observation light toward the measurement position 1220 may be employed in spectrophotometers other than the spectrophotometer 1000 having an object color with a d:8 geometry. The spectrum of light transmitted through the sample may also be measured.

[0081] 2 Second Implementation

[0082] 2.1 Main differences between the first and second embodiments

[0083] The primary difference between the first and second embodiments is that, while in the first embodiment, observation light source 1084 is inserted into measurement optical path 1120 when observing measured position 1220, in the second embodiment, the observation light source is always positioned along the optical path of the zero-order light generated by the measured light reflected by the diffraction grating. The structure of spectrophotometer 1000 of the first embodiment or its variations can also be applied to the spectrophotometer of the second embodiment, to the extent that this primary difference is not prevented.

[0084] 2.2 Spectrophotometer

[0085] Figure 5 Schematic diagram illustrating a spectrophotometer according to a second embodiment.

[0086] Figure 5The illustrated spectrophotometer 2000 includes an illumination optical system 2020 , a light-receiving optical system 2021 , a spectrometer 2022 , a controller 2023 , an operation unit 2024 , and a camera 2025 .

[0087] The illumination optical system 2020 includes an illumination light source 2040 and an integrating sphere 2041. The light receiving optical system 2021 includes a light receiving lens 2060. The spectrometer 2022 includes a slit plate 2080, a lens 2081, a diffraction grating 2082, a line sensor 2083, and an observation light source 2084. The slit plate 2080 has a slit 2100 formed therein.

[0088] 2.3 Spectral measurement

[0089] When measuring a spectrum, the illumination light source 2040 emits illumination light for illuminating the sample according to control by the controller 2023 .

[0090] The emitted illumination light enters the space 2160 formed inside the integrating sphere 2041 through the opening 2140 formed in the side surface of the integrating sphere 2041, and is diffusely reflected multiple times by the diffuse reflection surface 2180 surrounding the space 2160. Thus, the illumination light becomes uniform diffuse illumination light.

[0091] The uniform diffuse illumination light is emitted from the measurement aperture 2200 formed in the integrating sphere 2041, illuminates the area facing the measurement aperture 2200, and is reflected by the surface of the sample arranged at the measurement position 2220. Thus, the measurement light 2240 is generated from the measurement position 2220.

[0092] The generated light to be measured 2240 is imaged by the light receiving lens 2060. Thus, imaged light to be measured 2280 is generated.

[0093] The imaged light 2280 to be measured passes through the slit 2100 , thereby generating light 2300 to be measured that travels along the measurement optical path 2120 between the slit 2100 and the diffraction grating 2082 .

[0094] Measured light 2300 traveling along measurement optical path 2120 is guided by lens 2081 and diffracted and reflected by diffraction grating 2082. Diffraction generates diffracted light, including -1st-order diffracted light 2320. Reflection generates 0th-order light 2321. Because measured light 2300 traveling along measurement optical path 2120 undergoes wavelength dispersion due to diffraction, -1st-order diffracted light 2320 becomes wavelength-dispersed light.

[0095] The generated −1st-order diffracted light 2320 is received by the line sensor 2083 .

[0096] The line sensor 2083 outputs a signal indicating a spectrum corresponding to the received −1st-order diffracted light 2320 .

[0097] 2.4 Observation of the measured position

[0098] The spectrophotometer 2000 has a function of irradiating the measurement position 2220 with observation light. The operator can observe the measurement position 2220 by recognizing the bright spot or bright line that appears when the observation light is irradiated onto the measurement position 2220 through the detector hole 2340 formed in the integrating sphere 2041.

[0099] The observation light source 2084 is positioned on the optical path of the 0th-order light 2321. Because the optical path of the 0th-order light 2321 is outside the measurement optical path 2120, the observation light source 2084 does not need to be retracted during spectrum measurement. Consequently, the observation light source 2084 and the reflective mirror that reflects the observation light do not need to be movable, and a drive mechanism to move the observation light source 2084 or the reflective mirror that reflects the observation light is unnecessary.

[0100] When observing the measured position 2220 , the observation light source 2084 emits observation light toward the diffraction grating 2082 in accordance with the control by the controller 2023 .

[0101] The emitted observation light is reflected by the diffraction grating 2082 , passes through the slit 2100 , and is imaged by the light-receiving lens 2060 .

[0102] When observation light source 2084 emits observation light, an image of slit 2100 is formed on the surface of the sample. Since the position where the image of slit 2100 is formed is the measured position 2220, the operator can observe the measured position 2220 by viewing the image of slit 2100 through detector aperture 2340 formed in integrating sphere 2041.

[0103] In the second embodiment, unlike the first embodiment, it is not necessary to arrange the slit 2100 at a position optically conjugate with the position to be measured 2220 .

[0104] According to the spectrophotometer 2000 of the second embodiment, observation light can be irradiated onto the measured position 2220 without providing a large space inside the spectrophotometer 2000, and the measured position 2220 can be easily observed. In addition, according to the spectrophotometer 2000 of the second embodiment, there is no need to add a component such as a reflecting mirror.

[0105] Furthermore, according to the spectrophotometer 2000 of the second embodiment, even when the light-emitting area of ​​the observation light source 2084 is small, observation light can be irradiated onto the entire entrance pupil of the spectrometer 2022. Therefore, the NA of the observation light that has passed through the slit 2100 is the same as the NA of the spectrometer 2022. Therefore, even when the slit 2100 is not provided at a position optically conjugate with the measurement position 2220, the entire measurement area can be observed.

[0106] 2.5 Observing the wavelength of light

[0107] The observation light may have a wavelength outside the wavelength range of the spectrum being measured. For example, if the wavelength range of the spectrum being measured is in the visible region, the observation light may have a wavelength in the ultraviolet or infrared region. Thus, since the observation light does not affect the spectrum measurement, the measured position 2220 can be observed while the spectrum is being measured.

[0108] When the observation light has a wavelength outside the wavelength range of the spectrum to be measured, the camera 2025 has sensitivity with respect to the wavelength of the observation light and photographs the measured position 2220 .

[0109] 2.6 Diffraction Grating Configuration

[0110] Figure 6 It is a perspective view illustrating the arrangement of a diffraction grating of a spectrophotometer according to a second embodiment. Figure 7 It is a perspective view showing the arrangement of the diffraction grating in comparison with the arrangement of the diffraction grating of the spectrophotometer according to the second embodiment.

[0111] like Figure 6 As shown, in the spectrophotometer 2000 of the second embodiment, a diffraction grating 2082 is provided to deviate the −1st-order diffracted light 2320 from a plane 2500 including the principal ray of the measured light 2300 and the principal ray of the 0th-order light 2321 traveling on the measurement optical path 2120 .

[0112] like Figure 7As shown in the figure, when -1st-order diffracted light 2320 does not deviate from plane 2500, which includes the principal ray of measured light 2300 and the principal ray of 0th-order light 2321 traveling along measurement optical path 2120, -1st-order diffracted light 2320 generated by diffraction grating 2082 of measured light 2300 is directed toward the same position as first-order diffracted light 2322 generated by diffraction grating 2082 of light on the optical path of 0th-order light 2321. Line sensor 2083 receives both -1st-order diffracted light 2320 and first-order diffracted light 2322. Therefore, reflected light generated by observation light source 2084 reflecting 0th-order light 2321, or fluorescence emitted by observation light source 2084 when receiving 0th-order light 2321, becomes stray light, affecting spectral measurement.

[0113] In contrast, Figure 6 As shown in the figure, when diffraction grating 2082 is rotated relative to -1st-order diffracted light 2320 and 0th-order light 2321, and -1st-order diffracted light 2320 deviates from plane 2500, which includes the principal ray of measured light 2300 and the principal ray of 0th-order light 2321 traveling along measurement optical path 2120, -1st-order diffracted light 2320 generated by diffraction grating 2082 of measured light 2300 is directed to a position different from the position directed by first-order diffracted light 2322 generated by diffraction grating 2082 of light on the optical path of 0th-order light 2321. Line sensor 2083 receives -1st-order diffracted light 2320 but does not receive first-order diffracted light 2322. Therefore, reflected light generated by reflection of 0th-order light 2321 by observation light source 2084, or fluorescence emitted by observation light source 2084 when receiving 0th-order light 2321, does not affect spectral measurement.

[0114] While the present invention has been described in detail, the above description is in all aspects illustrative and not restrictive, and it will be appreciated that numerous modifications not shown herewith may be devised without departing from the scope of the present invention.

[0115] Description of Reference Numerals

[0116] 1000, 2000 spectrophotometer;

[0117] 1020, 2020 Illumination Optical System;

[0118] 1021, 2021 Light receiving optical system;

[0119] 1022, 2022 optical splitter;

[0120] 1023, 2023 controller;

[0121] 1024, 2024 operation department;

[0122] 1060, 2060 light receiving lens;

[0123] 1080, 2080 slit plate;

[0124] 1081, 2081 lens;

[0125] 1082, 2082 diffraction grating;

[0126] 1083, 2083 line sensors;

[0127] 1084, 1380, 2084 Observe the light source;

[0128] 1085 plug-in mechanism;

[0129] 1100, 2100 slit;

[0130] 1120, 2120 measurement optical path;

[0131] 1220, 2220 measured position;

[0132] 1240, 2240 measured light;

[0133] 1320, 2320 - 1st order diffraction light;

[0134] 1400, 1401, 1402 LEDs;

[0135] 2025 Camera;

[0136] 2321 0th order light.

Claims

1. A spectrophotometer comprising: an illumination optical system comprising an illumination light source and an integrating sphere having a measurement opening, and illuminating a sample arranged opposite the measurement opening with diffuse light diffused by the integrating sphere; a light receiving optical system for imaging the light to be measured incident from the position to be measured through the measurement opening to generate imaged light to be measured; a slit forming body disposed at an image forming position of the light receiving optical system and having a slit formed therein for allowing the light to be measured to pass therethrough to generate the light to be measured that travels on a measurement optical path; a wavelength dispersion element for performing wavelength dispersion on the light to be measured traveling along the measurement optical path to generate wavelength dispersed light to be measured; a sensor having a plurality of photoelectric conversion elements arranged in a wavelength dispersion direction, receiving the wavelength-dispersed light to be measured and outputting a signal representing a spectrum; an observation light source configured to irradiate the slit with light from the wavelength dispersion element side and emit observation light, the observation light forming an image of the slit formed by the light receiving optical system at the measured position of the sample; a target mask that blocks external light in such a manner that the gap between the integrating sphere and the sample is not entered; an auxiliary light source that emits light simultaneously with the observation light from the observation light source and emits auxiliary illumination light that illuminates an area other than the measured position in a recognizable manner; A detector is used to observe the measured position.

2. The spectrophotometer according to claim 1, wherein: The wavelength dispersion element is a diffraction grating, The observation light source is arranged on an optical path of the 0th-order light generated by the light to be measured being reflected by the diffraction grating.

3. The spectrophotometer according to claim 1, wherein: When observing the position to be measured, the observation light source is inserted into the measurement light path between the sensor and the slit. During measurement of the light to be measured, the observation light source is retracted outside the measurement light path.

4. The spectrophotometer according to claim 1, wherein: The integrating sphere has an aperture for the detector.

5. The spectrophotometer according to claim 1, wherein: The detector has a camera.

6. The spectrophotometer according to claim 1, wherein: The observation light source includes a plurality of light sources, each of which emits a plurality of lights having different colors from each other. The spectrophotometer further includes a switching device that switches the light used as the observation light among the plurality of lights.

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