JP6041691B2 - Measuring apparatus and measuring method - Google Patents

Description

  The present invention relates to a measuring apparatus and a measuring method for measuring the optical performance of a phosphor.

  Conventionally, various phosphors containing a fluorescent material have been used in various applications. In recent years, it has been widely applied to light emitting devices using LEDs (Light Emitting Diodes) and the like, display devices such as liquid crystal displays and organic EL (Electro Luminescence) displays, and the like. Since such a phosphor affects the performance of the light emitting device and the display device, it is necessary to appropriately evaluate the optical performance.

  As a configuration related to the evaluation of such a phosphor, Japanese Patent Laid-Open No. 2012-208024 (Patent Document 1) discloses a configuration for measuring a fluorescence spectrum of a phosphor used in a light emitting device by being dispersed in a sealing material. Is disclosed.

JP 2012-208024 A

  The configuration disclosed in the above-mentioned JP2012-208024A (Patent Document 1) is directed to measuring a phosphor spectrum of a sample (sample) in which a phosphor is dispersed in a sealing material, Basically, it is assumed that the fluorescence spectrum of each sample (sample) is measured.

  On the other hand, in the phosphor production line, there is a need to measure a plurality of phosphors to be inspected in a shorter time. For example, manufacturing and inspection are performed in the state of a sheet whose entire surface is a phosphor. Such a sheet having the entire surface made of a phosphor is used as a product by cutting out a region having a necessary dimension. In the configuration disclosed in Japanese Patent Laid-Open No. 2012-208024 (Patent Document 1), it is necessary to perform measurement by bringing an integrating sphere into contact with a plate-like sample (sample). Therefore, when measuring fluorescence spectra at a plurality of measurement points on the same plane, it is necessary to repeat the movement of the integrating sphere and the contact with the sample (sample), and it is difficult to reduce the time required for the measurement.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a measuring apparatus and a measuring method capable of measuring the optical performance of a phosphor in a shorter time. is there.

  A measuring device for measuring the optical performance of a phosphor according to an aspect of the present invention includes a light source for irradiating the phosphor with excitation light, light of the excitation light that has passed through the phosphor, and excitation light. And a detection unit for detecting the light received by the light receiving unit. The light receiving unit is arranged on the opposite side of the housing having a predetermined length in the excitation light irradiation direction, the light diffusing unit disposed on the phosphor side of the housing, and the light diffusing unit of the housing, and the incident fluorescence Including a window for guiding the light to the detection unit.

Preferably, the light receiving unit is arranged at a predetermined distance from the phosphor.
Preferably, the light diffusing unit is arranged in a range including the field of view from the window.

  Preferably, the measurement apparatus further includes a moving mechanism that changes a position where excitation light from the light source enters the phosphor.

  Preferably, a plurality of light receiving units are arranged according to a predetermined rule with respect to the phosphor, and the detection unit measures fluorescence received by the plurality of light receiving units in parallel.

  A measurement method for measuring the optical performance of a phosphor according to another aspect of the present invention includes a step of irradiating a phosphor with excitation light from a light source, light of the excitation light transmitted through the phosphor, and excitation The method includes a step of receiving, with a light receiving unit, fluorescence generated by a phosphor by light, and a step of detecting, with a detection unit, light received by the light receiving unit. The light receiving unit is arranged on the opposite side of the housing having a predetermined length in the excitation light irradiation direction, the light diffusing unit disposed on the phosphor side of the housing, and the light diffusing unit of the housing, and the incident fluorescence Including a window for guiding the light to the detection unit.

  According to the present invention, the optical performance of the phosphor can be measured in a shorter time.

It is a schematic diagram which shows the whole structure of the measuring apparatus according to this Embodiment. It is a schematic diagram which shows the structural example of the detection part according to this Embodiment. It is a schematic diagram which shows the structural example of the processing apparatus according to this Embodiment. It is a schematic diagram for demonstrating generation | occurrence | production of the fluorescence in a sheet-like sample. It is a schematic diagram which shows the structure for measuring the optical performance of a sheet-like sample using an integrating sphere. It is a figure which shows an example of the cosine characteristic of an integrating sphere. It is a schematic diagram which shows the structure for measuring the optical performance of a sheet-like sample using a hemispherical integrating sphere. It is a schematic diagram which shows the structure for measuring the optical performance of a sheet-like sample using the measuring apparatus according to this Embodiment. It is a figure which shows an example of the cosine characteristic of the light-receiving part of the measuring apparatus according to this Embodiment. It is a figure which shows an example of the measurement result of chromaticity using the light-receiving part of the measuring apparatus according to this Embodiment. 11 is a graph in which the measurement results shown in FIG. 10 are plotted with respect to the distance between the sample and the light receiving unit. About the measurement result shown in FIG. 10, the graph which plotted the difference of chromaticity x and chromaticity y regarding the distance of a sample and a light-receiving part is shown. It is a figure which shows an example of the measurement result of the spectrum using the light-receiving part of the measuring apparatus according to this Embodiment. It is a schematic diagram for demonstrating the light reception angle in the light-receiving part according to this Embodiment. It is a graph which shows the change of the light reception angle at the time of changing a light projection diameter, maintaining the light reception diameter in the light-receiving part according to this Embodiment. It is a graph which shows the change of the light reception angle at the time of changing a light reception diameter in the light-receiving part according to this Embodiment, maintaining a light projection diameter. It is a schematic diagram which shows an example of the test | inspection apparatus containing the measuring apparatus according to this Embodiment. It is a flowchart which shows the procedure which measures the optical performance of a sample using the test | inspection apparatus shown in FIG. It is a schematic diagram which shows an example of the test | inspection apparatus containing the measuring apparatus according to this Embodiment. It is a schematic diagram which shows an example of the test | inspection apparatus containing the measuring apparatus according to this Embodiment.

  Embodiments of the present invention will be described in detail with reference to the drawings. Note that the same or corresponding parts in the drawings are denoted by the same reference numerals and description thereof will not be repeated.

<A. Schematic configuration of measuring device>
First, a schematic configuration of the measuring apparatus according to the present embodiment will be described. FIG. 1 is a schematic diagram showing an overall configuration of measuring apparatus 1 according to the present embodiment. The measuring device 1 measures the optical performance of the phosphor. Hereinafter, the phosphor to be measured is also referred to as “sample 2”.

  Referring to FIG. 1, measurement apparatus 1 irradiates sample 2 with excitation light, and detects light transmitted through a phosphor among the excitation light and fluorescence generated in sample 2 by the excitation light. . Typically, the measurement apparatus 1 is a transmission type fluorescence measurement apparatus.

  The measurement apparatus 1 shown in FIG. 1 receives an irradiation unit 50 for irradiating the sample 2 with excitation light, light that has passed through the phosphor among the excitation light, and fluorescence generated in the sample 2 by the excitation light. The light receiving unit 10, the detection unit 200 for detecting the light received by the light receiving unit 10, and the processing device 300.

  The irradiation unit 50 includes a light source 52 for generating excitation light, a condensing lens 54 disposed on the optical axis of the excitation light, and a power supply device 56 for driving the light source 52. The light source 52 is designed to generate excitation light including a wavelength band corresponding to the characteristics of the sample 2. More specifically, a blue LED or the like is employed as the light source 52. Alternatively, the light source 52 may be a halogen light source, a xenon light source, a mercury lamp, or the like with a spectroscope. By adopting these light sources, excitation light including a specific wavelength can be generated. The condensing lens 54 includes an optical system for converting excitation light from the light source 52 into parallel light. The power supply device 56 supplies power corresponding to the type of the light source 52.

  When the excitation light from the irradiation unit 50 enters the sample 2, the wavelength component corresponding to the component and composition of the sample 2 is absorbed and fluorescence is generated. Of the excitation light, light that has not been absorbed or reflected is output as transmitted light. The light receiving unit 10 receives the generated fluorescence and transmitted light and guides them to the detection unit 200.

  The light receiving unit 10 does not directly receive the fluorescence and transmitted light from the sample 2 but receives the light after passing through the light diffusion unit 14. That is, the light receiving unit 10 is disposed on the opposite side of the housing 12 having a predetermined length in the excitation light irradiation direction, the light diffusion unit 14 disposed on the sample 2 side of the housing 12, and the sample 2 of the housing 12. And a window 18 for guiding the incident fluorescence to the detection unit 200.

  The casing 12 is configured to have a predetermined length in the irradiation direction of the excitation light (optical axis direction) in order to maximize the visual field range (cross-sectional area) from the window 18. Typically, the cylindrical housing 12 is preferable, but the cross-sectional shape of the housing 12 is not limited to a circle. For example, a cylindrical structure having a hexagonal or octagonal polygonal cross-sectional shape may be employed. That is, any shape may be adopted as long as the visual field range (cross-sectional area) from the window 18 is not limited by the inner surface 16 of the housing 12. Furthermore, as the housing 12, a shape such as a cone or a truncated cone having a larger cross-sectional area on the light diffusion portion 14 side and a smaller cross-sectional area on the window 18 side may be employed.

  The light diffusing unit 14 is for integrating (homogenizing) the fluorescence emitted from the sample 2 in each direction. Typically, the light diffusing unit 14 is realized by a diffusion sheet having a predetermined translucency. The light diffusing unit 14 does not need to cover the entire opening of the housing 12, but preferably covers the entire light guided to the detecting unit 200 through the window 18. That is, the light diffusing unit 14 is arranged in a range including the visual field 24 from the window 18. By passing through such a light diffusing unit 14, it is possible to obtain substantially the same effect as integrating (homogenizing) fluorescence using an integrating sphere.

  A connection end 22 of an optical fiber 20 for optically connecting the light receiving unit 10 and the detection unit 200 is inserted into the window 18, and light incident on the light receiving unit 10 is detected via the optical fiber 20. Guided to 200. As the optical fiber 20, a configuration composed of a plurality of strands may be adopted. In that case, a plurality of strands are gathered at the connection end 22. When such a connection end 22 is used, the visual field 24 is determined according to the numerical aperture of the optical fiber 20. Alternatively, a slit may be adopted as the window 18. In this case, the visual field 24 is determined according to the slit width and the like. Further, the detection unit 200 and the light receiving unit 10 may be directly connected without using the optical fiber 20.

  The detection unit 200 detects the light received by the light receiving unit 10. Typically, the detection unit 200 measures the spectral irradiance of incident light. As an example of such a detection unit 200, a spectrophotometer capable of measuring a characteristic value included in fluorescence for each wavelength is used. As the spectrophotometer, a monochromator that measures a characteristic value at a single wavelength may be employed, or a polychromator that simultaneously measures a characteristic value (spectrum) in a certain wavelength range may be employed. When the spectrum is not necessary as the characteristic value of the sample 2 and only chromaticity is necessary, a chromaticity sensor may be employed. An appropriate detection unit 200 is selected according to the evaluation item requested for the sample 2.

  FIG. 2 is a schematic diagram showing a configuration example of the detection unit 200 according to the present embodiment. In FIG. 2, the example which implement | achieved the detection part 200 using the spectrophotometer (polychromator) is shown. More specifically, the detection unit 200 includes a diffraction grating 202, a detection element 204, a shutter 206, and a slit 208. The light incident through the optical fiber 20 is reflected by the diffraction grating 202 after passing through the slit 208. In the diffraction grating 202, each wavelength component included in the light is reflected in each direction according to the wavelength. Then, each reflected wavelength component is incident on a region corresponding to the wavelength of the detection element 204. The surface area of the detection element 204 is divided into predetermined unit areas, and the received light spectrum is detected based on the intensity value in each unit area.

  The shutter 206 blocks light incident on the detection unit 200 when performing dark correction or the like. Furthermore, in order to reduce stray light components and the like, a cut filter that blocks light having a wavelength outside the measurement wavelength range may be disposed after the shutter 206.

  Referring to FIG. 1 again, processing device 300 calculates and outputs the optical performance of sample 2 based on the detection signal output from detection unit 200. The optical performance of Sample 2 includes evaluation values such as brightness and hue in addition to spectral characteristics (spectral irradiance). Here, the brightness means the luminance and luminous intensity of the sample 2, and the hue means the chromaticity coordinates, dominant wavelength, stimulus purity, correlated color temperature, and the like of the sample 2.

  FIG. 3 is a schematic diagram showing a configuration example of the processing apparatus 300 according to the present embodiment. As shown in FIG. 3, the processing apparatus 300 is typically realized by a general-purpose computer. More specifically, the processing device 300 includes a CPU (Central Processing Unit) 302, a main memory RAM (Random Access Memory) 304, a hard disk (HDD) 306, an optical disk drive 308, an input unit 310, A display unit 312 and an input / output interface 314. These components are connected to each other via a bus 316.

  The hard disk 306 is installed with a measurement program 307 for realizing a measurement process described later. The measurement program 307 is expanded in the RAM 304 or the like and executed by the CPU 302. Such a program is stored in a recording medium such as the optical disk 309 or distributed via a network or the like. A program stored and distributed in a recording medium such as the optical disk 309 is read from the recording medium by the optical disk drive 308 or the like and installed in the hard disk 306.

  The input unit 310 includes a keyboard, a mouse, a touch panel, and the like, and receives commands and operations from the user. The display unit 312 includes a display and various indicators, and outputs a measurement result calculated by the processing device 300.

  The input / output interface 314 outputs commands to components included in the measurement apparatus 1 and receives input signals from the detection unit 200 and the like. As the input / output interface 314, a general-purpose interface such as USB (Universal Serial Bus) may be adopted. Furthermore, an output device such as a printer may be connected to the input / output interface 314 as necessary.

  In the processing apparatus 300 of the measuring apparatus 1 according to the present embodiment, an example has been described in which a general-purpose processor (CPU 302) implements a measurement process as will be described later by executing a program. The unit may be realized by using a dedicated processor or IC (Integrated Circuit). Alternatively, a dedicated hardware circuit such as an ASIC (Application Specific Integrated Circuit) may be used.

<B. Background and Related Technologies>
(1: Background and needs)
As described above, the phosphor is an indispensable material for manufacturing a light emitting device and a display device. In a typical phosphor production line, the phosphor is manufactured in sheet form, and quality control is also performed in that state. As part of such quality control, in-plane distribution measurement of the optical performance of the phosphor sheet is required. In order to improve the production efficiency of such a phosphor sheet, quick measurement (inspection) is required. That is, in the production line, there is an increasing need to measure a plurality of measurement points set on the phosphor sheet in a shorter time. There is also a growing need for a function capable of calibrating a measuring apparatus with a simplified procedure so that measurement can be performed stably in the long run as the measurement speeds up.

(2: Generation of fluorescence)
FIG. 4 is a schematic diagram for explaining the generation of fluorescence in the sheet-like sample 2. As shown in FIG. 4, the light distribution pattern of the fluorescence generated by irradiating the sheet-like sample 2 with excitation light varies depending on the type of sample 2 (phosphor) and the measurement position. Furthermore, the fluorescent light distribution pattern varies depending on the wavelength. Therefore, it is not easy to measure the optical performance of the sheet-like sample 2.

(3: Measurement using an integrating sphere)
First, as a related technique, a configuration for measuring the optical performance of the sheet-like sample 2 using an integrating sphere will be described.

  FIG. 5 is a schematic diagram showing a configuration for measuring the optical performance of the sheet-like sample 2 using an integrating sphere. Referring to FIG. 5, the sample 2 is irradiated with excitation light, and transmitted light and fluorescence generated by the irradiation of the excitation light are integrated (homogenized) by an integrating sphere 90 and then dispersed in the light receiving window 94. Measure irradiance. A reflection plate (baffle) 92 is provided in front of the light receiving window 94 to prevent incident light from reaching the light receiving window 94 directly.

  Since the integrating sphere 90 is a sphere, the range in contact with the sample 2 is also curved. For this reason, the integrating sphere 90 is provided with an incident window 96 including a base in a range in contact with the sample 2. That is, the surface of the base formed on the plane comes into contact with the sample 2, and the fluorescence from the sample 2 is received in the integrating sphere 90. Here, the base needs to have a thickness of about 10 to 15 mm, and the optical performance of fluorescence may not be accurately measured depending on the thickness. That is, depending on the light distribution pattern of the fluorescence from the sample 2, the thickness of the base may interfere with the emission of the fluorescence, and accurate measurement may not be performed.

  Further, it is necessary to perform measurement by bringing the integrating sphere 90 into contact with the sample 2. When the in-plane distribution is measured with respect to the phosphor sheet, contact and separation are repeated between the integrating sphere 90 and the sample 2. It is necessary to increase the measurement efficiency.

  Furthermore, when the integrating sphere 90 is used, the incident light characteristics may be deteriorated due to the influence of the reflection plate 92 inside.

  FIG. 6 is a diagram illustrating an example of a cosine characteristic of an integrating sphere. That is, the cosine characteristic shown in FIG. 6 shows the oblique characteristic of the incident light viewed from the incident window 96 of the integrating sphere 90 (the relationship between the incident angle and the relative intensity at the incident window). FIG. 6 shows examples in which the diameter of the integrating sphere is 2 inches and 4 inches, respectively. As the name of the cosine characteristic indicates, the oblique characteristic of the incident light should ideally match the cosine function (cos θ). However, the actual cosine characteristic of the integrating sphere 90 has deviated from the ideal characteristic.

(4: Measurement using hemispherical integrating sphere)
Next, a configuration for measuring the optical performance of the sheet-like sample 2 using a hemispherical integrating sphere will be described. FIG. 7 is a schematic diagram showing a configuration for measuring the optical performance of the sheet-like sample 2 using the hemispherical integrating sphere 80. Referring to FIG. 7, a hemispherical integrating sphere 80 is an integrating device that combines a hemisphere having an inner surface provided with a diffuse reflection layer and a disc having an inner surface provided with a specular reflection layer. For details of the hemispherical integrating sphere 80, refer to, for example, Japanese Patent Application Laid-Open No. 2009-103654. In the hemispherical integrating sphere 80 shown in FIG. 7, the transmitted light and fluorescence from the sample 2 are received through the sample window 86 provided on the disk, and the received light is integrated inside the hemispherical integrating sphere 80 ( And the spectral irradiance is measured in the light receiving window 84. In addition, a reflection plate (baffle) 82 is provided in front of the light receiving window 84 to prevent incident light from reaching the light receiving window 84 directly.

  Unlike the case of using the integrating sphere 90 shown in FIG. 5, in the hemispherical integrating sphere 80, the portion that contacts the sample 2 (sample window 86) is planar. For this reason, the portion irradiated with the sample 2 does not inhibit the fluorescence irradiation from the sample 2. That is, by using the hemispherical integrating sphere 80, it is possible to receive all of the emitted fluorescence without depending on the fluorescence light distribution pattern from the sample 2, and to realize accurate measurement.

  However, similarly to the case where the integrating sphere 90 shown in FIG. 5 is used, even when the hemispherical integrating sphere 80 is used, the hemispherical integrating sphere 80 needs to be brought into contact with the sample 2 for measurement. Therefore, if the in-plane distribution is measured for the phosphor sheet, it is necessary to repeat contact and separation between the hemispherical integrating sphere 80 and the sample 2, and the measurement efficiency cannot be increased.

<C. Measuring apparatus according to the present embodiment>
(1: Configuration)
FIG. 8 is a schematic diagram showing a configuration for measuring the optical performance of the sheet-like sample 2 using the measuring apparatus 1 according to the present embodiment. As described with reference to FIG. 1, the light receiving unit 10 includes a housing 12 having a predetermined length in the excitation light irradiation direction, and a light diffusing unit 14 disposed on the sample 2 side of the housing 12. Here, the light receiving unit 10 is arranged at a predetermined distance from the sample 2. The distance d between the sample 2 and the light receiving unit 10 shown in FIG. 8 takes into account the relationship between the projection diameter φ0 that is the spot of the excitation light and the light receiving diameter φ1 of the housing 12, the transmittance of the light diffusion unit 14, and the like. Optimized.

  In order to increase the measurement sensitivity and the measurement accuracy, it is preferable to reduce the distance d between the sample 2 and the light receiving unit 10 and increase the aperture (light receiving diameter φ1) of the light receiving unit 10. Further, it is preferable that the light receiving diameter φ1 is sufficiently larger than the light projecting diameter φ0 (φ1 >> φ0).

  By adopting the configuration as shown in FIG. 8, it is not necessary to bring the light receiving unit 10 into contact with the sample 2 at the time of measurement, so that the time required for measuring the in-plane distribution on the phosphor sheet can be shortened. In addition, since the optical path is short, the light receiving sensitivity can be increased, and higher throughput can be realized. For example, it is necessary for each of the case where fluorescence is measured using the same detector 200 using the light receiving unit 10 according to the present embodiment and the case where fluorescence is measured using the hemispherical integrating sphere 80. When the exposure time is compared, it takes 5500 ms when the hemispherical integrating sphere 80 is used, but 450 ms when the detection unit 200 composed of the light diffusion unit 14 having a thickness of 15 mm is used. there were. That is, the exposure time can be reduced to about 1/10 by using the light receiving unit 10 according to the present embodiment. In other words, by using the light receiving unit 10 according to the present embodiment, the brightness of the fluorescence incident on the light receiving unit 10 is increased about 10 times, and the throughput can be increased about 10 times. By increasing the throughput in this way, the tact time of the production line can be shortened.

  Furthermore, since the apparatus configuration can be simplified as compared with the case where an integrating sphere is used, the apparatus can be made more compact and the cost can be reduced.

(2: Measurement performance)
In measuring apparatus 1 according to the present embodiment, it is possible to suppress deterioration of incident light characteristics. FIG. 9 is a diagram showing an example of the cosine characteristic of the light receiving unit 10 of the measuring apparatus 1 according to the present embodiment. That is, the cosine characteristic shown in FIG. 9 shows the oblique characteristic of the incident light viewed from the light diffusing unit 14 of the light receiving unit 10 (the relationship between the incident angle and the relative intensity in the light diffusing unit 14). As shown in FIG. 9, the oblique characteristic of the incident light of the light receiving unit 10 substantially matches the ideal cosine characteristic, and the measurement accuracy can be further improved as compared with the case where the integrating sphere 90 is used.

(3: Distance between sample and light receiver)
Next, the distance d between the sample 2 and the light receiving unit will be described. As described above, by measuring the optical performance of the sample 2 using the hemispherical integrating sphere 80 shown in FIG. 7, the measurement accuracy can be improved as compared with the case where the integrating sphere 90 is used. Therefore, in the following examination, the measurement result obtained when the hemispherical integrating sphere 80 is used is regarded as a reference value.

  FIG. 10 is a diagram illustrating an example of a chromaticity measurement result using the light receiving unit 10 of the measurement apparatus 1 according to the present embodiment. FIG. 10 shows the results of measurement performed by varying the distance d between the sample 2 and the light receiving unit 10. In the measurement result shown in FIG. 10, the reference value of the chromaticity (chromaticity x and chromaticity y) measured using the hemispherical integrating sphere 80 shown in FIG. 7 under the conditions of the same sample 2 and detection unit 200. The difference is shown. That is, Δx and Δy shown in FIG. 10 indicate the difference between the measurement results for chromaticity x and chromaticity y, respectively, and the color difference is the square root of the square sum of Δx and Δy (color difference = √ (Δx ^ 2 + Δy ^ 2) ).

  FIG. 11 shows a graph in which the measurement results shown in FIG. 10 are plotted with respect to the distance d between the sample 2 and the light receiving unit 10. FIG. 12 shows a graph in which the difference between the chromaticity x and the chromaticity y is plotted with respect to the distance d between the sample 2 and the light receiving unit 10 for the measurement result shown in FIG.

  As shown in FIGS. 10 to 12, the color difference, that is, the difference (error) from the measurement result (reference value) using the hemispherical integrating sphere 80 is changed by changing the distance d between the sample 2 and the light receiving unit 10. It can be seen that it can be minimized. In other words, the measurement accuracy can be increased by optimizing the distance d between the sample 2 and the light receiving unit 10. More specifically, using a coordinate system with the distance d and the color difference between the sample 2 and the light receiving unit 10 as shown in FIG. 11 as axes, or the difference in chromaticity x and color as shown in FIG. An optimum value of the distance d can be determined using a coordinate system having the degrees y as axes. 10 to 12, it can be seen that the distance d between the sample 2 and the light receiving unit 10 is preferably about 10 mm.

  FIG. 13 is a diagram showing an example of a spectrum measurement result using the light receiving unit 10 of the measurement apparatus 1 according to the present embodiment. FIG. 13 shows the results of measurement performed by varying the distance d between the sample 2 and the light receiving unit 10. The intensity of the spectrum is standardized and expressed as a relative intensity.

  Among the spectra shown in FIG. 13, the spectrum closest to the spectrum measured using the hemispherical integrating sphere 80 shown in FIG. 7 under the conditions of the same sample 2 and detection unit 200 is the sample 2 and the light receiving unit 10. The distance d is set to about 10 mm. That is, it is the same as the distance d determined from the measurement results shown in FIGS.

  As described above, it is preferable to obtain a reference measurement value in advance and optimize the distance d between the sample 2 and the light receiving unit 10 so as to most closely match the reference value.

(4. Light receiving angle at the light receiving part)
Next, the light receiving angle in the light receiving unit 10 will be described. FIG. 14 is a schematic diagram for illustrating a light receiving angle in light receiving unit 10 according to the present embodiment.

  As shown in FIG. 14, the light receiving angle θ of the light receiving unit 10 is defined as the maximum angle at which the fluorescence generated from the sample 2 can enter the light receiving unit 10. This light receiving angle θ basically depends on three parameters: the distance d between the sample 2 and the light receiving unit 10, the projection diameter φ 0 (spot diameter of the excitation light), and the light receiving diameter φ 1 (the aperture of the light receiving unit 10). Therefore, for example, when the distance d between the sample 2 and the light receiving unit 10 is changed, other parameters are also adjusted so that the light receiving angle θ is the same before and after the change of the distance d. Is preferred.

  FIG. 15 is a graph showing changes in the light reception angle when the light projection diameter φ0 is changed while the light reception diameter φ1 is maintained in the light receiving unit 10 according to the present embodiment. FIG. 16 is a graph showing changes in the light receiving angle when the light receiving diameter φ1 is changed while maintaining the light projecting diameter φ0 in the light receiving unit 10 according to the present embodiment.

  As shown in FIG. 15, when the projection diameter φ0 is changed, the reception angle θ changes. Therefore, in order to maintain the same reception angle θ before and after the change of the projection diameter φ0, the sample 2 and the light receiving unit 10 It is also necessary to adjust the distance d. On the other hand, as shown in FIG. 16, even if the light receiving diameter φ0 is changed, the light receiving angle θ changes. The degree of change in the light receiving angle θ is larger than that when the projection diameter φ0 is changed. Therefore, in order to maintain the same light receiving angle θ before and after the change of the light receiving diameter φ1, it is necessary to adjust the distance d between the sample 2 and the light receiving unit 10, and this adjustment amount changes the light emitting diameter φ0. It becomes larger than the case.

<D. Application Example 1>
(1: Overall configuration)
Next, an application example of measuring apparatus 1 according to the present embodiment will be described. FIG. 17 is a schematic diagram showing an example of an inspection apparatus 400 including the measuring apparatus 1 according to the present embodiment. The inspection apparatus 400 measures the in-plane distribution of the optical performance of the phosphor sheet. More specifically, the inspection apparatus 400 includes a measurement dark box 410 and a calibration dark box 420. The sample 2 is placed in the measurement dark box 410 and irradiated with excitation light from the excitation light source 62. The fluorescence generated by the irradiation of the excitation light is measured by the detection unit 200 via the light receiving unit 10 and the optical fiber 20.

  More specifically, the excitation light generated by the excitation light source 62 is guided to the irradiation unit 60 via the optical fiber 66. The excitation light irradiated from the irradiation unit 60 propagates toward the sample 2. Transmitted light and fluorescence generated from the sample 2 by the incidence of excitation light are received by the light receiving unit 10 and guided to the detection unit 200 via the optical fiber 20. Here, in order to change the position of the excitation light incident on the sample 2, a sample stage 412 is provided in the measurement dark box 410. That is, the sample stage 412 corresponds to a moving mechanism that changes the position at which the excitation light from the excitation light source 62 enters the sample 2 (phosphor). The sample stage 412 can be moved to an arbitrary position in accordance with an instruction from the position controller 414.

  A wavelength selection unit 64 is provided on the irradiation side of the excitation light source 62, and is configured to be able to select a wavelength suitable for measurement. As the wavelength selection unit 64, a filter using a spectroscope can be employed. Furthermore, a plurality of different types of light sources may be prepared so that they can be appropriately selected according to the sample 2 to be measured. When the wavelength of the excitation light changes, the amount of transmitted light and the amount of fluorescence change. Therefore, it is important to control the wavelength of the excitation light to be constant in a transmission type fluorescence measuring apparatus.

  In addition, you may mount the function to perform light control of the excitation light source 62. FIG. As the dimming function, the excitation light is emitted in a state where the sample stage 412 is moved so that the sample 2 does not exist on the excitation light path, and the light emission of the excitation light source 62 is performed based on the measurement result at that time. Adjust the strength. Since the amount of transmitted light and the amount of fluorescence change when the wavelength of the electromotive light changes, it is important to control the wavelength of the excitation light to be constant in the transmission type fluorescence measuring apparatus.

  The detection unit 200 measures the spectrum of light incident through the light receiving unit 10 and the optical fiber 20. The processing device 300 sequentially stores the measurement results obtained by the detection unit 200 in association with the corresponding positions (coordinate values) of the sample 2. The measurement results include chromaticity (chromaticity x and chromaticity y) in the CIE color system, correlated color temperature, and the like. As the position (coordinate value) of the sample 2, the position information of the position controller 414 is used.

  Furthermore, the processing apparatus 300 can also determine the quality of the target sample 2 based on the measured in-plane distribution. Sample 2 is defective when, for example, the optical performance is non-uniform in the plane (variation exceeds a predetermined threshold value), or the measured chromaticity is within a predetermined threshold range. The case where it exceeds is mentioned.

  The inspection apparatus 400 shown in FIG. 17 further has a calibration function. More specifically, a calibration standard light source 422 is arranged in the calibration dark box 420. At the time of calibration, the light receiving unit 10 is arranged in the calibration dark box 420 and the standard light source 422 is turned on by the standard light source 424. Calibration (pricing) is performed on the measurement value by the detection unit 200 at this time. The correction calculation necessary for calibration is executed in the detection unit 200 and / or the processing device 300.

(2: Processing procedure)
Next, a procedure for measuring the optical performance of the sample 2 using the inspection apparatus 400 shown in FIG. 17 will be described. FIG. 18 is a flowchart showing a procedure for measuring the optical performance of the sample 2 using the inspection apparatus 400 shown in FIG. The arithmetic processing shown in FIG. 18 is typically realized by the processing device 300 executing a program.

  Referring to FIG. 18, first, calibration for the spectral irradiance detected by detection unit 200 is executed. More specifically, the user places the light receiving unit 10 in the calibration dark box 420 and turns on the standard light source 422 (step S2). The processing device 300 compares the reference spectrum priced to the standard light source 422 with the measurement value by the detection unit 200, and determines the calibration coefficient (step S4).

  Subsequently, dimming of the excitation light applied to the sample 2 is executed. That is, the spectral irradiance of the excitation light from the excitation light source 62 is measured, and the emission intensity of the excitation light source 62 is adjusted so that the measured spectral irradiance falls within a predetermined range. When the amount of excitation light changes, the value of transmitted fluorescence changes, so that the amount of excitation light needs to be constant for measurement of samples of the same type.

  More specifically, the user arranges the light receiving unit 10 in the measurement dark box 410, moves the sample stage 412 to a predetermined position so that the sample 2 does not exist on the optical path of the excitation light, and then selects the wavelength. The wavelength is set by controlling the unit 64, and the excitation light source 62 is turned on (step S6). Subsequently, the processing device 300 determines whether or not the spectral irradiance measured by the detection unit 200 is within a specified range and whether or not the peak wavelength is out of the set wavelength (step S8). When the spectral irradiance measured by the detection unit 200 is not within the specified range and / or when the peak wavelength is out of the set wavelength (NO in step S8), the processing device 300 is excited. A command for adjusting the intensity of the excitation light is output to the light source 62 (step S10). Then, the process of step S8 is repeated.

  On the other hand, when the spectral irradiance measured by the detection unit 200 is within the specified range and the peak wavelength does not deviate from the set wavelength (in the case of YES in step S8), the measurement for the sample 2 is performed. Processing begins. Specifically, the processing apparatus 300 outputs a command for moving the sample stage 412 and matches the measurement point of the sample 2 with the optical path of the excitation light (step S12). The detector 200 measures the spectral irradiance of the transmitted light and the fluorescence generated from the sample 2 upon receiving the excitation light received by the light receiver 10 (step S14). Then, the processing apparatus 300 stores the measurement result by the detection unit 200 in association with the current position (coordinates) of the sample 2 (or the sample stage 412) (step S16).

  During the measurement of the in-plane distribution on the sample 2, the excitation light source 62 may always be irradiated with the excitation light, or when the positioning of the sample 2 is completed, the excitation light is irradiated in a spot manner. Also good.

  Subsequently, the processing device 300 determines whether or not the measurement has been completed for all measurement points of the sample 2 (step S18). When there is a measurement point for which measurement has not been completed among the measurement points for sample 2 (NO in step S18), processing device 300 outputs a command for moving sample stage 412 and The next measurement point is matched with the optical path of the excitation light (step S20). And the process after step S14 is performed.

  On the other hand, when the measurement has been completed for all measurement points of sample 2 (YES in step S18), processing device 300 outputs the stored measurement result (step S22). At this time, processing for calculating various optical characteristics, processing for determining the presence or absence of abnormality, and the like may be additionally performed.

With the above procedure, the measurement for one sample 2 is completed.
(3: Modification)
FIG. 17 typically shows a case where measurement is performed on one sample 2, but in an actual production line, it is necessary to efficiently measure a large number of samples 2. In such a case, for example, the following configuration can be adopted.

  FIG. 19 is a schematic diagram showing an example of an inspection apparatus 402 including measurement apparatus 1 according to the present embodiment. FIG. 19A shows a plan view of the inspection apparatus 402, and FIG. 19B shows a side view of the inspection apparatus 402. In this inspection apparatus 402, a plurality of sheet-like samples 2 are arranged on a sample holder according to a predetermined rule. In the example shown in FIG. 19A, an example in which four samples 2 are arranged in one sample holder 440 is shown. A plurality of (9 in FIG. 19) measurement points are set in the surface of one sample 2, and the optical performance is measured at each measurement point. When it is determined to be defective based on the measurement result at any of the measurement points, the sample 2 including the measurement point is marked to indicate that it is defective (with a marking device (not shown)).

  Each of the sample holders 440 on which the plurality of samples 2 are arranged is attached to the cassette 450. The cassette 450 is configured to be stacked in the direction of gravity. A plurality of cassettes 450 stacked in this way are stored in the sample storage unit 490. The transfer robot 460 sequentially inserts the arm 462 into each slot of the cassette 450 and transfers the sample holder 440 stored in the target slot to the sample stage 412. This movement of the sample holder 440 is detected by an area sensor 464 provided in front of the sample stage 412. The required optical performance measurement is performed on the sample 2 in the sample holder 440 placed on the sample stage 412 according to the procedure described above.

  The irradiation unit 60 and the light receiving unit 10 are fixed to a support member 470 arranged in the vertical direction of the sample stage 412.

  By adopting the configuration as shown in FIG. 19, it is possible to continuously measure a plurality of samples 2. A plurality of sample storage portions 490 are preferably arranged. By arranging a plurality of sample storage units 490, a measurement process is being performed on a plurality of cassettes 450 stored in one sample storage unit 490, while another sample storage unit 490 is newly updated. A plurality of cassettes 450 can be mounted or a plurality of measured cassettes 450 can be taken out.

<E. Application Example 2>
In the above description, a configuration in which only a pair of the irradiation unit 50 for irradiating the sample 2 with excitation light and the light receiving unit 10 for receiving transmitted light and fluorescence generated in the sample 2 by the excitation light is arranged. Although illustrated, a plurality of pairs of the irradiation unit 50 and the light receiving unit 10 may be arranged.

  FIG. 20 is a schematic diagram showing an example of an inspection apparatus 500 including measurement apparatus 1 according to the present embodiment. In the inspection apparatus 500 illustrated in FIG. 20, a configuration example in which a plurality of pairs of the irradiation unit 50 and the light receiving unit 10 are arranged corresponding to a plurality of measurement points set in the sample 2 is illustrated. That is, in the inspection apparatus 500, a plurality of light receiving units 10 are arranged according to a predetermined rule with respect to the sample 2 (phosphor), and the detection unit receives transmitted light and fluorescence respectively received by the plurality of light receiving units 10. Measure in parallel.

  In the configuration shown in FIG. 20, a multi-input spectrophotometer 220 can be used as the detection unit. The multi-input spectrophotometer 220 can simultaneously measure the spectral irradiances of a plurality of fluorescent lights in parallel using, for example, a plurality of line sensors arranged in parallel. By using such a multi-input spectrophotometer 220, the time required for measurement can be further shortened, the configuration of the sample stage 412 can be simplified, or a configuration without using the sample stage 412 can be realized. Instead of the multi-input spectrophotometer 220, a chromaticity sensor may be attached to the light receiving unit 10 to simultaneously measure the transmitted fluorescence chromaticity in parallel.

  FIG. 20 shows a configuration in which pairs of the irradiation unit 50 and the light receiving unit 10 are arranged in a matrix, but it is not always necessary to arrange them in a matrix, and only one column may be arranged. Furthermore, when the measurement points are set in a zigzag pattern, the pair of the irradiation unit 50 and the light receiving unit 10 may be arranged at positions corresponding to the measurement points set in such a zigzag pattern.

<F. Advantage>
According to the present embodiment, when measuring the optical performance of the phosphor, it is not necessary to contact the sample as in the case of using an integrating sphere, and the light receiving unit is disposed at a predetermined distance from the sample. Since it can be measured, in-plane distribution measurement can be performed in a shorter time. Moreover, since there is no contact with a sample, it can avoid damaging a sample accidentally.

  According to the present embodiment, a calibration function can be implemented, and calibration can be performed with respect to the spectral irradiance at the light diffusing unit of the light receiving unit. By implementing such a calibration function, the measurement itself can be stabilized in the long term.

  According to the present embodiment, it is possible to implement a dimming function for the excitation light source, and the light intensity of the excitation light can be kept constant by this dimming function. By implementing such a dimming function, the measurement itself can be stabilized in the long term.

  In the above description, the fluorescence to be measured, which mainly describes the case where a fluorescent material widely applied to a light emitting device, a display device, and the like is a measurement target, is not limited to these. For example, it can be applied to measurement of fluorescence generated from a Langmuir Blodgett (LB) film or a functional molecular film, fluorescence generated from a biological cell or protein, and the like.

  The embodiment 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, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Measuring apparatus, 2 samples, 10 Light-receiving part, 12 Housing, 14 Light-diffusion part, 16 Inner surface, 18 Window, 20,66 Optical fiber, 22 Connection end, 24 Field of view, 50,60 Irradiation part, 52 Light source, 54 Condensing lens , 56 power supply device, 62 excitation light source, 64 wavelength selection unit, 80 hemispherical integrating sphere, 84, 94 light receiving window, 86 sample window, 90 integrating sphere, 92 reflector, 96 incident window, 200 detecting unit, 202 diffraction grating, 204 detection element, 206 shutter, 208 slit, 220 multi-input spectrophotometer, 300 processing device, 302 CPU, 304 RAM, 306 hard disk, 307 measurement program, 308 optical disk drive, 309 optical disk, 310 input unit, 312 display unit 314 I / O interface, 316 bus, 400, 02,500 Inspection device, 410 Dark box for measurement, 412 Sample stage, 414 Position controller, 420 Dark box for calibration, 422 Standard light source, 424 Power source for standard light source, 440 Sample holder, 450 cassette, 460 Transport robot, 462 arm, 464 Area sensor, 470 support member, 490 Sample storage.

Claims (6)

A measuring device for measuring the optical performance of a phosphor,
A light source for irradiating the phosphor with excitation light;
A light receiving unit that is disposed at a predetermined distance from the phosphor, receives light transmitted through the phosphor out of the excitation light, and fluorescence generated in the phosphor by the excitation light;
A detection unit for detecting light received by the light receiving unit,
The light receiving unit is
A housing having a predetermined length in the irradiation direction of the excitation light;
A light diffusion portion disposed on the phosphor side of the housing;
A measuring apparatus, which is disposed on the opposite side of the housing from the light diffusion part and includes a window for guiding incident fluorescence to the detection part. The measuring device according to claim 1 , wherein the light diffusing unit is arranged in a range including a visual field from the window. Further comprising a moving mechanism for changing the position at which excitation light from the light source is incident on the phosphor, the measurement apparatus according to claim 1 or 2. For the phosphor, a plurality of the light receiving parts are arranged according to a predetermined rule,
The measuring device according to any one of claims 1 to 3 , wherein the detection unit measures in parallel fluorescence received by a plurality of light receiving units. The said predetermined distance is defined according to the relationship between the projection diameter of the said excitation light and the light reception diameter of the said housing | casing, and the transmittance | permeability of the said light-diffusion part. measuring device. A measurement method for measuring the optical performance of a phosphor,
Irradiating the phosphor with excitation light from a light source;
A step wherein the phosphor in the light receiving section disposed apart by a predetermined distance, the light transmitted through the phosphor of the excitation light, and, for receiving light and fluorescence generated by the phosphor by the excitation light,
Detecting the light received by the light receiving unit with a detection unit,
The light receiving unit is
A housing having a predetermined length in the irradiation direction of the excitation light;
A light diffusion portion disposed on the phosphor side of the housing;
A measurement method comprising a window arranged on the opposite side of the housing from the light diffusing unit and for guiding incident fluorescence to a detection unit.

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