JP7396358B2 - two-dimensional spectrometer - Google Patents

Description

The present invention relates to a two-dimensional spectroscopic device capable of measuring the intensity of light from an object to be measured, such as a display, having at least one light emitting element, by dividing it into wavelengths.

The above-mentioned two-dimensional spectroscopic device is also called a hyperspectral camera, and can have as data the intensity distribution of different wavelengths for each pixel in the measurement area. For example, it is possible to divide the range from 350 nm to 800 nm into 90 bands of 5 nm each, and have intensity distribution data corresponding to each of the 90 wavelengths over the entire measurement region.

By the way, displays having light emitting elements have improved luminous efficiency and vividness by using natural light sources such as LEDs and OLEDs. In addition, the size of light emitting sources has gradually become smaller and the resolution of displays has become higher, making it difficult to perform spectroscopic evaluation of light emitting elements. Up until now, it has been possible to perform a sufficient evaluation using the average value of the spectroscopic spectrum within an evaluation area of 100 μm using a spot spectrometer, but it has become difficult to perform spectroscopic evaluation focusing on an arbitrary light emitting element. ing. For this reason, there is an increasing need to accurately extract the light emitting region of the light emitting element.

Note that Patent Document 1 proposes a two-dimensional colorimetric device that can improve the measurement accuracy of photometric quantities without excessively enlarging the photometric area. Specifically, the two-dimensional colorimetric device includes a two-dimensional imaging unit that has first pixels arranged two-dimensionally and captures an image of a color display screen on which a predetermined color is displayed; A plurality of photometry areas including one pixel are set in correspondence with a plurality of measurement areas, and the photometry amount (for example, chromaticity) of the measurement area corresponding to the photometry area is determined between the two-dimensional colorimeter and the color display screen. The apparatus includes an adjusting section that executes a first process of adjusting the photometric area for each of the plurality of photometric areas so that measurement variations due to positional relationships fall within a predetermined range.

JP2019-27869A

However, the two-dimensional colorimeter described in Patent Document 1 is not a technology related to extracting the light emitting region of a light emitting element, and therefore, there is no solution to accurately extracting the light emitting region of a light emitting element. It is not something that can be provided.

The present invention has been made in view of the above technical background, and provides a two-dimensional spectroscopic device that enables spectroscopic evaluation of any light emitting element by accurately extracting the light emitting region of the light emitting element. With the goal.

The above objective is achieved by the following means.
(1) A two-dimensional spectroscopic device that has a measurement region that includes a light emitting region of at least one light emitting element of a measurement target, and outputs a data cube that is the intensity of light for each of a plurality of wavelengths in the measurement region, The light emitting area of the light emitting element is smaller than the measurement area, and extraction data is created for each pixel of the image of the measurement area, based on the intensity measurement values for each of the plurality of wavelengths. means, a threshold value setting means for setting a first threshold value for the extraction data; and a threshold value setting means for setting a first threshold value for the extraction data; extracting pixels for which the extraction data is greater than or equal to the first threshold value; extracting means for setting a first light emitting region that is a light emitting region , the threshold value setting means setting a second threshold value smaller than the first threshold value, and the extraction means for determining whether the extraction data is the first light emitting region. A two-dimensional spectroscopic device that extracts pixels that do not exceed a first threshold but exceed the second threshold or exceed the second threshold, and sets the region of the extracted pixels as a second light emitting region .
(2) The two-dimensional spectrometer according to item 1, wherein the extraction data creation means uses intensity at a peak wavelength as the extraction data.
(3) The two-dimensional spectroscopic device according to item 1, wherein the extraction data creation means weights the intensity of an arbitrarily set wavelength range to generate extraction data.
(4) The two-dimensional spectrometer according to item 3, wherein the wavelength range is each of red, green, and blue wavelength ranges.

According to the invention described in the preceding paragraph (1), the two-dimensional spectrometer has a measurement region that includes a light emitting region of one light emitting element of the object to be measured, and the intensity of light for each of a plurality of wavelengths in the measurement region. Output data cube. Based on the intensity measurement values for each of a plurality of wavelengths, data for extracting a light emitting region is created for each pixel of the image of the measurement region. Furthermore, a first threshold value for the extraction data is set, pixels for which the extraction data is greater than or equal to the first threshold value are extracted, and the area of the extracted pixels is the light emitting area of the light emitting element . is extracted as a luminescent area .

In this way, since the light emitting region of the light emitting element can be automatically extracted, the extracted light emitting region can be set as the measurement region. As a result, when performing spectroscopic evaluation of a light source in which a large number of tiny light-emitting elements with a width of about 100 μm to several tens of μm are lined up, for example, the measurement target is a display, it is possible to obtain data for a region that includes only the light source to be evaluated. . In particular, when the light-emitting area of a light-emitting element is not a rectangular or circular shape that is easy to set as a measurement area, it would take a lot of effort to manually set the light-emitting area, but with the present invention, the light-emitting area can be automatically extracted. Therefore, the light emitting area can be set as the measurement area without much effort.
In addition, by setting a second threshold smaller than the first threshold and comparing the extraction data with the first and second thresholds, it is possible to detect areas where the luminescence intensity is weak and different from what was expected. It is possible to extract a second light emitting region due to light leakage or the like.

According to the invention described in the above item (2), by using the intensity at the peak wavelength as the extraction data, it is possible to easily extract the light emitting region. In particular, in recent years self-luminous displays, etc., have become mainstream with configurations that have peaks at characteristic wavelengths such as red, green, and blue, and are ideal for extracting the light-emitting regions of sub-pixels of each color. Become.

According to the invention described in the previous section (3), since the intensity of an arbitrarily set wavelength range is weighted and used as extraction data, it is possible to extract a light emitting region with less influence of noise and with higher accuracy. can.

According to the invention described in the preceding item (4), the intensity of each wavelength range of red, green, and blue is weighted and used as extraction data, which is suitable for extracting the light emitting region of each color subpixel. becomes.

FIG. 1 is a block diagram showing the configuration of a two-dimensional spectroscopic device according to an embodiment of the present invention. FIG. 3 is a diagram showing an example of a measurement target. It is a graph showing an example of spectral distribution of a red light emitting element. This is an enlarged view of a part of FIG. 2, and is an explanatory diagram of pixels corresponding to each of a light-emitting region and a non-light-emitting region. FIG. 3 is a diagram showing a state in which light emitting regions of each light emitting element are extracted. FIG. 7 is a diagram showing another example of the measurement target. FIG. 3 is a diagram showing an example of spectral distribution of red, green, and blue light emitting elements. FIG. 7 is a diagram showing a state in which a red light emitting region is extracted from the measurement target of FIG. 6; FIG. 7 is a diagram illustrating a state in which a green light emitting region in the measurement target of FIG. 6 is extracted. 7 is a diagram showing a state in which a blue light emitting region is extracted from the measurement target of FIG. 6. FIG. FIG. 7 is a diagram showing a state in which the light emitting regions of each light emitting element in the measurement target of FIG. 6 are extracted. It is a graph which shows another example of the spectral distribution of each red, green, and blue light emitting element. FIG. 3 is a diagram illustrating an example of an object to be measured that has, in addition to the original light emitting element, a weak blue light emitting portion that is not used as excitation light and leaks out. It is a graph which shows the relationship between the spectral distribution of light from a blue light emitting part, and a 1st and 2nd threshold value. FIG. 6 is a diagram showing a state in which a light emitting region of a blue light emitting section is extracted.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a diagram showing the configuration of a two-dimensional spectroscopic device 1 according to an embodiment of the present invention. The two-dimensional spectrometer 1 is what is called a hyperspectral camera, and in this embodiment, the object 2 to be measured is a light source having a plurality of light emitting elements 3, such as a display.

As shown in FIG. 1, the two-dimensional spectrometer 1 includes a light receiving sensor 11, a spectrum measuring section 12, an extraction data creating section 13, a threshold setting section 14, and an extracting section 15.

The light receiving sensor 11 has a plurality of pixels arranged two-dimensionally. The spectrum measurement unit 12 measures the intensity of light from the measurement object 2 received by each pixel of the light receiving sensor 11 for each of a plurality of wavelengths λ, and outputs a data cube. The method of measuring the intensity of light at each of multiple wavelengths and outputting a data cube is well known, so the explanation will be omitted. A method may be used in which light-receiving areas are provided to expose different wavelengths corresponding to the number of bands, and any method may be used.

The extraction data creation unit 13 uses the spectrum measurement unit 12 to generate extraction data for determining whether each pixel of the image of the measurement area of the measurement object 2 obtained by the light receiving sensor 11 is a light emitting area. It is created for each pixel based on intensity measurements for a plurality of measured wavelengths. This point will be discussed later.

The threshold setting unit 14 sets a threshold for the created extraction data. The threshold value may be set in advance or may be set by the user.

The extraction unit 15 extracts pixels that are determined to be light emitting regions by comparing the created extraction data with a set threshold, and extracts the region of the extracted pixels as the light emitting region 4. Specifically, when the extraction data is equal to or greater than the first threshold, the pixel is determined to be a light emitting region.

Next, a specific extraction process for the light emitting region 4 of the light emitting element 3 will be explained.
[First embodiment]
In this embodiment, as shown in FIG. 2, the measurement object 2 is a display in which monochromatic red (peak wavelength 670 nm) light emitting elements 31 are arranged at equal intervals (for example, 30 μm intervals) vertically and horizontally, and the drawing area shown in FIG. is defined as the measurement area 5 by the light receiving sensor 11. Therefore, as shown in FIG. 2, the light emitting area 41 of the light emitting element 31 (the part surrounded by the solid line) is smaller than the measurement area 5, and the light emitting area 41 of a plurality of light emitting elements 31, at least one in total, is in the measurement area 5. Existing.

When it is necessary to extract the light emitting region 41, the user operates a mode button (not shown) or the like to set an extraction mode. When the extraction mode is set, the intensity at a plurality of wavelengths is measured for each pixel of the image in the measurement area 5. In other words, two-dimensional intensity distribution data (data cube) measured at each wavelength is obtained for the measurement region 5. By calibrating the measured intensity, the brightness can be obtained.

An example of the measured spectral distribution of the red light emitting element 31 is shown in FIG. The spectral distribution shown in FIG. 3 is a spectrum measured for a pixel corresponding to the light emitting region 41 of the light emitting element 31, as shown in FIG. 4, and the intensity is strong in the red wavelength range. On the other hand, as shown in FIG. 4, the intensity at each wavelength is close to zero for the pixel corresponding to the non-light emitting area between the light emitting elements 31, 31.

Next, extraction data is created for each pixel. An example of the extraction data is the intensity P of the peak wavelength λ1 in the measured spectral distribution. The peak wavelength λ1 may be the peak wavelength of the spectral distribution measured for each pixel, the peak wavelength of a typical red spectral distribution, the pixels in the entire measurement area 5, or within an arbitrary reference area. It may be the average value of the peak wavelengths for the pixels.

Alternatively, the red wavelength range (570 nm to 750 nm) is set as the wavelength range of interest, and the measurement data is weighted according to the spectral distribution of red light emission in this wavelength range of interest, and the intensity in the wavelength range of interest is calculated to extract the data. It's good as well. Weighting according to the spectral distribution increases the weight of the measured data near the median of the wavelength range of interest, and decreases the weight of the measured data as it approaches the boundary value of the wavelength range of interest. are calculated and combined to obtain the intensity in the wavelength range of interest. Note that the wavelength range of interest may be set by the user. In this way, by weighting the measurement data in the wavelength range of interest to determine the intensity in the wavelength range of interest and creating extraction data, it is possible to suppress the influence of light emission variations of the light emitting elements 31, and to create a more accurate light emitting region 41. This is desirable because it allows extraction of

A threshold value (corresponding to the first threshold value) S1 is set for the extraction data as shown by the broken line in FIG. The threshold value S1 may be, for example, 50% of the maximum value in a typical red spectrum distribution, or may be 50% of the maximum value for pixels in the entire measurement area 5, or for pixels in an arbitrary reference area. may be used, or other values may be used. Further, the threshold value may be set by the user.

Here, pixels whose extraction data is greater than or equal to the threshold S1 correspond to the light-emitting region 41 of the light-emitting element 31, and pixels whose extraction data is less than or equal to the threshold S1 correspond to the non-light-emitting region between the light-emitting elements 31, 31. corresponds to In other words, for each pixel in the measurement area 5, it is checked whether the extraction data is equal to or greater than the threshold value S1, or whether it exceeds the threshold value S1, the pixels that are equal to or greater than the threshold value S1 are extracted, and the area of the extracted pixels is Use as a light emitting area. Through such processing, the light emitting region 41 of each light emitting element 31 is automatically extracted as surrounded by a broken line in FIG. The extracted light emitting region 41 may be displayed on the screen, and any extracted light emitting region 41 can be set as a measurement region on the screen or the like. Therefore, the spectrum can be measured and calculated again for each set independent measurement area, and the emission spectrum of each light emitting element 31 can be evaluated.

In this embodiment, a case is shown in which red light emitting elements 31 all having the same emission spectrum are lined up, and even if the spectrum is calculated again for each light emitting element 31, the same spectral distribution will be obtained. However, when the light emitting elements 31 have variations in emission wavelength, the emission spectrum differs from one light emitting element 31 to another.

As described above, in this embodiment, the extraction data of the light emitting region 41 is created based on the measured values for each of a plurality of wavelengths, and the threshold value S1 for the extraction data is further set, so that the extraction data is equal to or higher than the first threshold value S1. Alternatively, a region of pixels exceeding the first threshold value S1 is extracted as the light emitting region 41. In this way, since the light emitting region 41 of the light emitting element 31 can be automatically extracted, the extracted light emitting region 41 can be set as the measurement region. As a result, when performing spectroscopic evaluation of a light source in which a large number of tiny light-emitting elements with a width of about 100 μm to several tens of μm are lined up, for example, the measurement target is a display, it is possible to obtain data for a region that includes only the light source to be evaluated. . In particular, if the light emitting area 41 of the light emitting element 31 is not a square or a circle that is easy to set as a measurement area, it would take a lot of effort to manually set the light emitting area, but in the present invention, the light emitting area is automatically set. Since the light emitting area can be extracted, the light emitting area can be set as the measurement area without much effort.
[Second embodiment]
In the first embodiment, the case where the light emitting element 31 of the measurement target 2 is monochromatic red is explained, but in this embodiment, the light emitting element 31 of the measurement target 2 is monochromatic red. This is an example where each light emitting element is mixed.

Specifically, as shown in FIG. 6, red light-emitting elements 31, green light-emitting elements 32, and blue light-emitting elements 33 are arranged in vertical columns with the same color at equal intervals (e.g., 30 μm intervals), and in horizontal rows, they are arranged at equal intervals (for example, at intervals of 30 μm). The measurement object 2 is a display arranged at intervals of 30 μm, for example.

The drawing area in FIG. 6 is defined as the measurement area 5 of the light receiving sensor 11. The light emitting regions 41 to 43 of each of the light emitting elements 31 to 33 are smaller than the measurement region 5, and a total of a plurality of light emitting regions 41 to 43 exist within the measurement region 5, at least one light emitting region for each of the light emitting elements 31 to 33.

When it is necessary to extract the light emitting area of each of the light emitting elements 31 to 33, the user operates a mode button (not shown) or the like to set an extraction mode. When the extraction mode is set, the intensity at a plurality of wavelengths is measured for each pixel of the image in the measurement area 5. In other words, two-dimensional intensity distribution data measured at each wavelength is obtained for the measurement region 5. By calibrating the measured intensity, the brightness can be obtained.

FIG. 7 shows an example of the spectral distribution of each of the red, green, and blue light emitting elements 31 to 33. The spectral distribution shown in FIG. 7 has a peak wavelength and a peak intensity in each of the red, green, and blue wavelength ranges, as indicated by the arrows. Therefore, a pixel corresponding to the light emitting region of any one of the red, green, and blue light emitting elements 31 to 33 exhibits one of the peaks in the vector distribution.

Therefore, similarly to Embodiment 1, the peak intensity at the peak wavelength of each pixel is used as extraction data, a threshold is set and compared with the extraction data, and for each pixel of the image of the measurement area 5, the extraction data is set to the threshold. It is checked whether it is equal to or greater than the threshold value or whether it exceeds the threshold value, and pixels that are equal to or greater than the threshold value or exceed the threshold value are extracted, and the region of the extracted pixels is set as a light emitting region.

FIG. 8 shows a state in which the light emitting region 41 of each red light emitting element 31 is extracted, as surrounded by a broken line, when the peak intensity in the red wavelength range is used as extraction data.

FIG. 9 shows a state in which the light emitting region 42 of each green light emitting element 32 is extracted, as surrounded by a broken line, when the peak intensity in the green wavelength range is used as extraction data.

FIG. 10 shows a state in which the light emitting region 43 of each blue light emitting element 33 is extracted, as surrounded by a broken line, when the peak intensity in the blue wavelength range is used as extraction data.

Note that the extracted light emitting regions 41 to 43 of each color may be displayed on the screen for each color, or as shown in FIG. 11, the light emitting regions 41 to 43 of each color may be displayed on the screen in a combined state. It's okay to be.

In this way, any light emitting regions 41 to 43 of the extracted red, green, and blue light emitting elements 31 to 33 can be set as measurement regions on the screen or the like. Therefore, the spectrum can be measured and calculated again for each set independent measurement area, and the emission spectrum of each of the light emitting elements 31 to 33 can be evaluated.
[Third embodiment]
In the second embodiment, the extraction data for each pixel is the peak intensity at the peak wavelength. The wavelength range (400 nm to 500 nm) is the wavelength range of interest, and in each of these wavelength ranges, the measurement data is weighted according to the spectral distribution of red, green, and blue light, and the intensity in each wavelength range of interest is calculated. It may be calculated and used as data for extraction. In the spectral distribution shown in FIG. 12, the range surrounded by the broken line represents the blue wavelength range, the range surrounded by the dashed-dotted line represents the green wavelength range, and the range surrounded by the dashed-two dotted line represents the blue wavelength range. There is.

Weighting according to the spectral distribution increases the weight of measured data near the median value of each wavelength range of interest, and decreases the weight of measured data as it approaches the boundary value of the wavelength range of interest. The intensities of the wavelength range of interest may be calculated and synthesized to obtain the intensity of the wavelength range of interest. In this case as well, by comparing the extraction data with the threshold value, it is possible to extract light emitting regions similar to the light emitting regions shown in FIGS. 8 to 10. In this case as well, the extracted light emitting regions 41 to 43 of each color may be displayed on the screen for each color, or as shown in FIG. may be displayed.

Note that although the number of wavelength ranges of interest is three, it may be two or four or more, and the user may be able to select arbitrarily.
[Fourth embodiment]
In this embodiment, two different threshold values are set for determining whether the area is a light emitting area or not.

In displays and the like, as shown in measurement object 2 in FIG. 13, green or red light emitted with blue fluorescence may be used in a light emitting element. In such a case, in addition to the original light emitting element 33, a weak blue light emitting portion 33a may be generated that is not used as excitation light and leaks out. In this embodiment, the light emitting region of such a weak blue light emitting section 33a is extracted.

FIG. 14 shows the spectral distribution of light for pixels existing in the light emitting region of the blue light emitting section 33a. As can be seen from FIG. 14, the light from the blue light emitting element 33a has a peak intensity at a blue wavelength, but the peak intensity is smaller than the peak intensity of the normal blue light emitting element 33, which is used in the first to third embodiments. It is smaller than the first threshold value S1, and a light emitting region cannot be extracted by comparison with the first threshold value S1.

Therefore, we set a second threshold S2 smaller than the threshold S1, and extracted pixels whose peak intensity does not exceed the first threshold S1 but exceeds the second threshold S2 or exceeds the second threshold S2. The region of the pixel is defined as a light emitting region 43a of the blue light emitting section 33a, as shown in FIG.

Although the peak intensity was compared with the first threshold S1 and the second threshold S2 as extraction data, the extraction data may be created by weighting the intensity in the blue wavelength range. In addition, instead of directly comparing the peak intensity etc. with the first threshold value S1 and the second threshold value S2, the light from the blue light emitting section 33a is determined based on the difference with the peak intensity etc. of the normal blue light emitting element 33. It is also possible to compare and evaluate the peak intensity, etc. of , and each threshold value.

In this way, in the fourth embodiment, by setting the second threshold S2 smaller than the first threshold S1 and comparing the extraction data with the first threshold S1 and the second threshold S2, It is possible to extract a light-emitting region 43a due to light leakage, etc., where the light-emitting intensity is weak and a different region than expected is illuminated.

The present invention can be used to measure the intensity of light from an object to be measured, such as a display having at least one light emitting element, by dividing it into wavelengths.

1 Two-dimensional spectrometer 11 Light receiving sensor 12 Spectrum measurement unit 13 Intensity cross section creation unit 14 Threshold value setting unit 15 Extraction unit 2 Measurement object 3 Light emitting element 31 Red light emitting element 32 Green light emitting element 33 Blue light emitting element 33a Blue light emitting element 4, 41 ~43, 43a Light emitting area 5 Measurement area 5a, 5b Pixel S1 First threshold S2 Second threshold

Claims (4)

A two-dimensional spectroscopic device that has a measurement region that includes a light emitting region of at least one light emitting element of a measurement target, and outputs a data cube that is the intensity of light for each of a plurality of wavelengths in the measurement region,
The light emitting area of the light emitting element is smaller than the measurement area,
Extraction data creation means for creating light emitting region extraction data for each pixel of the image of the measurement region based on the intensity measurement values for each of the plurality of wavelengths;
Threshold value setting means for setting a first threshold value for the extraction data;
Extracting means for extracting pixels for which the extraction data is greater than or equal to the first threshold value, and setting the region of the extracted pixels as the first light emitting region, which is the light emitting region ;
Equipped with
The threshold setting means sets a second threshold smaller than the first threshold,
The extraction means extracts pixels for which the extraction data does not exceed the first threshold but is greater than or equal to the second threshold, and sets the region of the extracted pixels as a second light emitting region. Two-dimensional spectrometer. 2. The two-dimensional spectrometer according to claim 1, wherein the extraction data creation means uses intensity at a peak wavelength as the extraction data. 2. The two-dimensional spectroscopy apparatus according to claim 1, wherein said extraction data creation means weights the intensity of an arbitrarily set wavelength range to generate extraction data. 4. The two-dimensional spectrometer according to claim 3, wherein the wavelength ranges are red, green, and blue wavelength ranges.

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