KR20090056858A - Optical property measuring device - Google Patents

Abstract

The control means judges the light quantity of the measurement light incident on the basis of the detection output from the light receiving portion 26, and when the amount of light incident on the light receiving portion 26 is smaller than a predetermined lower limit value, the optical filter portion 22 The photosensitivity is switched to a smaller value, and when the amount of light incident on the light-receiving portion 26 is larger than a predetermined upper limit value, the photosensitivity in the optical filter portion 22 is switched to a larger value.

Description

Optical characteristic measuring device {APPARATUS FOR MEASURING OPTICAL PROPERTY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical property measuring apparatus for spectroscopically measuring light from a light emitter, and more particularly to a technique for expanding a measurable luminance range.

BACKGROUND With the recent development of blue light emitting diodes (LEDs), establishment of mass production technology, and the like, white LEDs that generate light having a wide wavelength band using blue LEDs have been put into practical use. This white LED has high luminous efficiency, and realizes high brightness compared with the conventional red LED or the like.

By the way, in the production line of LED, the inspection process which judges whether the said product is defective by measuring brightness or a hue after turning on the LED actually manufactured is present. In such an inspection process, a measuring apparatus is arrange | positioned in the position spaced apart by the predetermined distance from the LED (light emitting body) used as a measurement object, and it is judged whether the defect is based on the light measured in the said position.

For example, Japanese Patent Application Laid-Open No. 2002-195882 discloses an LED illuminant inspection device comprising an LED sensor unit that detects light emission of an inspection object and determines the light emission state and a tester controller that performs final determination. This LED illuminant inspection device detects a plurality of luminance values in accordance with the effective wavelength value of light using a plurality of optical filters having filter characteristics corresponding to different emission colors of the illuminant.

In order to evaluate to include the color tone of the light emitting body, after measuring the spectral distribution of the light intensity, not the configuration using a plurality of optical filters as disclosed in Japanese Patent Application Laid-open No. 2002-195882, the International Illumination Commission (CIE : It is preferable to evaluate using the tristimulus value etc. in the XYZ colorimeter prescribed | regulated by Commission International del'Eclairange).

With the development of technologies such as higher efficiency and larger size, in particular, the light emission luminance of white LEDs is gradually increasing. On the other hand, in actual production lines, small LEDs etc. with relatively low emission luminance are often manufactured. Therefore, using the same measuring device, there is a need to measure LEDs having relatively high light emission brightness and LEDs having relatively low light emission brightness. However, compared with the measurable luminance range (dynamic range) in a spectroscopic detection part, the difference (ratio) between the high luminescence brightness and the low luminescence brightness may become large among the light emitting objects used as a measurement object. In such a case, the optical characteristics of all the light-emitting bodies cannot be measured in a state where the measurement device and the light-emitting body (LED) to be inspected are kept at the same distance. That is, when the distance between the measuring device and the light emitting object to be inspected is made relatively large in order to measure the light emitting body having high light emission luminance, a problem arises that the measurement accuracy of the light emitting body having low light emission luminance is deteriorated, and the light emission luminance is low. In order to measure the luminous body, when the distance between the measuring device and the luminous body to be inspected is made relatively small, a problem such as overrange occurs in the spectroscopic detection unit.

Therefore, the measurement may be performed after changing the distance between the measuring device and the light emitter to be inspected according to the light emission luminance, or the measurement may be performed in a state in which the brightness is suppressed by reducing the current value applied to the light emitter. do. However, in the former method, recalibration is necessary with changing the position of a measuring apparatus, and work becomes complicated. In the latter method, since the light emission characteristics of the light-emitting body (LED) are changed by reducing the supply current, the original optical characteristics cannot be accurately evaluated.

This invention is made | formed in order to solve such a subject, The objective is to provide the optical characteristic measuring apparatus which can easily expand the dynamic range, when spectroscopically measuring the light from a light-emitting body.

An optical property measuring apparatus according to one aspect of the present invention includes a spectroscopic detector for outputting a signal corresponding to the intensity of each wavelength component included in the light, a light guide for guiding light from the light emitter to the spectroscopic detector, and a spectrophotometer from the light guide. An optical filter unit disposed on an optical path to the detection unit and capable of switching a plurality of photosensitivity of transmitted light, and control means for controlling the photosensitivity in the optical filter unit. The control means judges the amount of light incident on the spectroscopic detector based on the signal output from the spectroscopic detector. When the amount of light incident on the spectroscopic detector is smaller than the predetermined lower limit value, the control means determines the value of the photosensitivity in the optical filter portion to be smaller. When the amount of light incident on the spectroscopic detection unit is larger than the predetermined upper limit value, the photosensitive ratio at the optical filter unit is switched to a larger value.

Preferably, the optical property measuring apparatus further includes computing means for calculating at least one of the brightness and chromaticity coordinates of the light emitter based on the signal output from the spectroscopic detector. The calculating means corrects the signal using a correction coefficient corresponding to the reduction ratio selected by the optical filter unit among the plurality of correction coefficients stored in advance corresponding to each of the plurality of reduction ratios in the optical filter unit.

Preferably, the optical filter portion includes a plate-shaped member in which a plurality of regions having different transmittances are formed, and a driving portion for driving the plate-shaped member in a direction perpendicular to the optical axis of light incident on the spectroscopic detection portion in accordance with instructions from the control means. .

More preferably, the plate-shaped member is formed by forming a plurality of regions having different transmittances from each other on a common glass substrate.

More preferably, the spectroscopic detection unit includes a diffraction grating into which light after passing through the optical filter unit is incident, and a light receiving unit which receives diffracted light generated by the diffraction grating. The plate-shaped member is disposed at a predetermined angle other than zero with respect to the vertical plane of the optical axis of the light whose plate surface is incident on the diffraction grating.

Preferably, the optical property measuring apparatus is configured to sequentially measure a plurality of light emitters continuously conveyed on a production line. The control means uses the photosensitive factor in the optical filter part used at the time of the last measurement as an initial value.

An advantage of the present invention is that the dynamic range can be easily expanded when spectroscopically measuring light from the light emitter.

These and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the invention which is understood in connection with the accompanying drawings.

According to the present invention, it is possible to provide an optical characteristic measuring apparatus that can easily expand its dynamic range when spectroscopically measuring light from a light emitting body.

EMBODIMENT OF THE INVENTION Embodiment of this invention is described in detail, referring drawings. In addition, about the same or equivalent part in drawing, the same code | symbol is attached | subjected and the description is not repeated.

<Device-wide configuration>

1 is a diagram showing an appearance of an optical characteristic measurement apparatus 1 according to an embodiment of the present invention.

With reference to FIG. 1, the optical characteristic measuring apparatus 1 which concerns on embodiment of this invention typically represents optical characteristics, such as brightness and hue of the some light emitting object OBJ conveyed continuously on the production line 10, and the like. Measure Here, the brightness means the brightness, the brightness, and the like of the light emitter OBJ, and the color tone means the chromaticity coordinates, the dominant wavelength, the stimulus purity, and the correlated color temperature of the light emitter OBJ. The optical characteristic measuring apparatus 1 according to the present embodiment can be applied to the measurement of a light emitting diode (LED) or a flat panel display (FPD), but in the following description, an LED is typically used. The structure made into the light-emitting body OBJ of a measurement object is illustrated.

In the production line 10, the light emitting object OBJ to be measured is conveyed at a constant speed or intermittently in a predetermined conveyance direction, and the optical characteristic measuring device 1 is located at a predetermined position (measurement position) on the production line 10. The optical properties of the light-emitting body OBJ. In addition, a power supply device (not shown) is connected to the bottom of the LED, which is the light emitter OBJ, at the measurement position and the position immediately before it (lighting ready position), and the LED is turned on. And a measurement is performed about LED of this lighting state. In addition, the position where the optical characteristic measuring apparatus 1 is arrange | positioned is generally each inspection process before shipment or during manufacture of a LED manufacturing line.

The optical property measuring apparatus 1 includes a detector 2 and an information processing apparatus 100. The detector 2 is connected via the light extraction part 6 and the optical fiber 4 arrange | positioned above the measurement position of the production line 10, etc. Then, the optical fiber 4 guides the light (hereinafter also referred to as "measurement light") from the light emitter OBJ to the detector 2.

The detector 2 spectroscopically measures the measurement light from the light emitter OBJ and transmits the measurement data including the signal (detection output) corresponding to the intensity of each wavelength component included therein to the information processing apparatus 100. Output In particular, the detector 2 according to the present embodiment includes an optical filter portion capable of switching a plurality of photosensitivity of light passing through as described later, and the measurement is performed by appropriately selecting the photosensitivity in this optical filter portion. Increase the possible luminance range (dynamic range). That is, when the luminance from the light emitter OBJ is relatively high, the photosensitivity is set relatively high, and when the luminance from the light emitter OBJ is relatively low, the light sensitivity is set relatively low, A light receiving unit such as a photodiode array for detecting the intensity is used in an appropriate sensitivity range. Thereby, appropriate detection accuracy can be maintained regardless of the brightness | luminance of the light emitting object OBJ.

The information processing apparatus 100 calculates the optical characteristics of the light emitter OBJ based on the measurement data from the detector 2. The information processing apparatus 100 is typically implemented by a computer. That is, the information processing apparatus 100 includes a computer main body 101 including a flexible disk (FD) driving device 111 and a compact disk-read 0 memory memory (CD-ROM) driving device 113, and a monitor 102. And a keyboard 103 and a mouse 104. And the computer main body 101 implements the program stored previously, and implements the calculation process of the optical characteristic with respect to the information processing apparatus 100. FIG. The functional configuration of this information processing apparatus 100 will be described later.

<Configuration of Detector>

2 is a schematic functional block diagram of a detector 2 according to an embodiment of the present invention. 3 is a perspective view showing the main part structure of the detector 2 according to the embodiment of the present invention.

2, the detector 2 includes a slit 20, an optical filter unit 22, a diffraction grating 24, a light receiving unit 26, an AD (Analog to Digital) converter 28, And a controller 30.

The slit 20, the optical filter portion 22, and the diffraction grating 24 are arranged on the optical axis Ax of the measurement light from the light emitter OBJ guided by the optical fiber 4. Therefore, the measurement light emitted from the light emitter OBJ propagates through the light extraction section 6 and the optical fiber 4 and first passes through the slit 20. The slit 20 adjusts the beam diameter (size) in order to realize a predetermined detection resolution. As an example, each slit width of the slit 20 is set to about 0.2 mm to 0.05 mm. The measurement light after passing through the slit 20 is incident on the optical filter part 22. In addition, the optical filter part 22 is arrange | positioned in the position substantially coinciding with the convergence position of the measurement light after passing through the slit 20. FIG.

The optical filter unit 22 is configured to be capable of switching a plurality of photosensitivity of light transmitted therethrough. The photosensitivity in the optical filter part 22 is selected according to the command from the controller 30 mentioned later.

In addition, the measurement light after passing through the optical filter unit 22 propagates on the optical axis Ax and enters the diffraction grating 24. The diffraction grating 24 is spectroscopy by diffracting incident measurement light, thereby inducing each diffracted light to the light receiving portion 26. Typically, the diffraction grating 24 is a reflective diffraction grating called a Brazed Holographic type, and is configured such that diffracted light at predetermined wavelength intervals is reflected in corresponding respective directions.

The light receiving unit 26 detects the intensity of each wavelength component included in the measurement light, and outputs an electric signal (detection output) corresponding to the detected intensity to the AD converter 28. The light receiving unit 26 typically includes a photodiode array (PDA) in which detection elements such as a photodiode and the like are arranged in an array shape, or a charged coupled device (CCD) and the like arranged in a matrix shape. As one example, the light receiving section 26 outputs a signal corresponding to the intensity of 512 frequency components in the range of 380 nm to 980 nm.

In addition, the diffraction grating 24 and the light receiving part 26 correspond to the "spectral detection part" in this application, and are designed suitably according to the detection wavelength range, detection wavelength spacing, etc. of a measurement light.

Next, with reference to FIG. 3, the structure of the principal part of the detector 2 is demonstrated. As described above, the slit 20, the optical filter unit 22, and the diffraction grating 24 are arranged on the optical axis Ax which is the optical path of the measurement light.

The optical filter portion 22 is disposed on the slit 20 side of the base member 212 such that the movable member 204 is slidably disposed in the direction perpendicular to the optical axis Ax. The movable member 204 is configured to be slidable along the guide member 210 extending in the slide direction provided on the base member 212. This movable member 204 is configured to be connected to the base member 212 via a return spring 206 and to be urged from the linear actuator 208. The return spring 206 applies a force for sliding the movable member 204 in the paper plane right direction. On the other hand, the linear actuator 208 moves in the slide direction of the movable member 204 in accordance with the instruction from the controller 30 (FIG. 2). By cooperation of the return spring 206 and the linear actuator 208, the movable member 204 slides to the position according to the movement amount of the linear actuator 208. As shown in FIG.

The movable member 204 is formed with a cutout including an area that intersects the optical axis Ax along with the slide, and is equipped with a plate-shaped filter array 202. Further, a cutout (not shown) is formed in the processing range including the optical axis Ax of the base member 212. Therefore, only the filter array 202 is a component of the optical filter part 22 which exists on the optical axis Ax.

The filter array 202 has a plurality of regions 202a, 202b, and 202c having different transmittances from each other on a common glass substrate.

4 is a configuration diagram of the filter array 202 shown in FIG.

4, three regions 202a, 202b, and 202c are formed in the filter array 202 according to the present embodiment as an example. In addition, as mentioned later, the detector which concerns on this invention should just be comprised so that a plurality of filters can be selected, and the number of the filters is not restrict | limited. More specifically, the filter array 202 is provided with a region 202a which has not been processed on the common glass substrate 203 and regions 202b and 202c having different transmittances in stages. Therefore, the transmittance of the region 202a corresponds to the transmittance of the glass substrate 203 itself, and since the glass substrate 203 having a relatively high transmittance is used in this embodiment, the photosensitive transmittance of the region 202a is substantially zero. Corresponds to On the other hand, the regions 202b and 202b are processed at 5% transmittance (ND5) and 0.2% transmittance (ND0.2) as an example. Therefore, the photosensitivity of the regions 202b and 202b is 1/20 and 1/500, respectively.

As shown in Fig. 3, the movable member 204 on which the filter array 202 is mounted slides in the vertical direction with respect to the optical axis Ax, so that of the regions 202a, 202b, and 202c formed in the filter array 202. The area | region which intersects the optical axis Ax is switched. That is, the photosensitivity can be different depending on which region of the areas 202a, 202b, and 202c the measurement light passes through.

Here, even when the photosensitivity is substantially zero (when the region 202a is selected), the measurement light is transmitted through the glass substrate 203. That is, even if any of the regions 202a, 202b, and 202c is selected, the measurement light passes through the glass substrate 203 at least. Therefore, by making the thickness of the glass substrate 203 large compared with the processing width | variety performed to implement | prescribe a predetermined transmittance | permeability, the fluctuation | variation of the optical path length of the measurement light accompanying switching of a photosensitive factor can be made small.

Moreover, since the photosensitivity can be switched only by sliding the filter array 202 formed by the common glass substrate 203, the space for realizing a switching structure can be made small.

In addition, the filter array 202 is preferably disposed at a predetermined angle other than zero with respect to the vertical plane of the optical axis Ax of the measurement light incident on the diffraction grating 24. This is because a part of the measurement light diffracted by the diffraction grating 24 propagates the optical axis Ax in the opposite direction to the measurement light and enters the filter array 202, and is also reflected by the filter array 202 to reflect the diffraction grating 24. May re-enter. As such, a measurement error may occur because a part of the measurement light is multiplely reflected between the filter array 202 and the diffraction grating 24. In order to exclude such an error factor, it is effective to shift the reflection direction by the filter array 202 of the return light which the measurement light is reflected by the diffraction grating 24 from the optical axis Ax.

5 is a view for explaining an installation state of the filter array 202 in the optical filter unit 22 according to the embodiment of the present invention. FIG. 6 is a view for explaining the optical path of the return light reflected by the filter array 202 shown in FIG.

Referring to Fig. 5, the movable member 204 is disposed so that its plate surface substantially coincides with the vertical plane of the optical axis Ax of the measurement light. Then, the filter array 202 is maintained at a predetermined angle θ other than zero with respect to the plate surface of the movable member 204, that is, the vertical plane of the optical axis Ax.

Fig. 6 shows an optical path of measurement light seen in the horizontal direction and return light generated by the measurement light. The measurement light incident on the diffraction grating 24 is diffracted by the diffraction grating 24, and a part of the diffracted light (multiple light) propagates in the opposite direction to the filter array 202 by propagating the optical axis Ax in the reverse direction. Enter. Here, by arranging the filter array 202 at a predetermined angle θ, of the returned light incident on the filter array 202, the component reflected by the filter array 202 is reflected by the predetermined angle θ from the optical axis Ax. Propagates in different directions. As a result, the return light reflected by the filter array 202 can be suppressed from re-incident to the diffraction grating 24.

In addition, the predetermined angle [theta] is based on the distance between the filter array 202 and the diffraction grating 24, the focal length of the diffraction grating 24, and the like. It is set at an appropriate angle that is not reentrant at 24. In reality, about 5 ° to 15 ° is preferable.

As shown in Fig. 5, the filter array 202 is configured to maintain a predetermined inclination angle about the slide axis of the movable member 204, so that even if any of the filters in the filter array 202 is selected, the filter array ( The relationship between the angle between 202 and the optical axis Ax is maintained. Therefore, irrespective of the filter selected, the conditions of the measurement light incident on the diffraction grating 24 can be made the same, and the occurrence of error accompanying filter switching can be suppressed.

In addition, since the filter array is plate-shaped, when the filter array 202 is mounted on the movable member 204, one process (typically, a counterbore (counterbore) portion) is performed, and the processing is performed. It can be simplified.

5 and 6 exemplify a configuration in which the filter array 202 is inclined about its bottom side, that is, a configuration in which the paper array is inclined in the vertical direction, but inclined around the side surface thereof. That is, you may employ | adopt the structure which inclines to a paper surface left-right direction. In essence, it is only necessary to avoid multiple reflections between the filter array 202 and the diffraction grating 24.

Again, referring to FIG. 2, the AD converter 28 converts the electrical signal from the light receiving section 26 into a digital signal, and outputs the digital signal after the conversion to the controller 30.

The controller 30 is configured to enable data communication with the information processing apparatus 100 (FIG. 1), and controls the switching of the photosensitive rate in the optical filter unit 22 as described later. The controller 30 also sets operating parameters such as the exposure time (gate time) of the light receiving unit 26. When the switching of the photosensitivity in the optical filter unit 22 is completed, the controller 30 transmits the measurement data including the detection output detected by the light receiving unit 26 to the information processing apparatus 100 at predetermined intervals. . Moreover, the transmission period of this measurement data is several msec to several hundred msec.

7 is a diagram showing an example of a data structure of measurement data transmitted from the detector 2 according to the embodiment of the present invention to the information processing apparatus 100.

Referring to Fig. 7, the data structure of the measurement data transmitted each time the measurement includes an ID storage unit 301, a measurement value storage unit 302, and a measurement information storage unit 303. The ID storage unit 301 stores ID numbers for specifying each measurement. This ID number is typically a number that increases with measurement. In the measurement value storage unit 302, a value representing the intensity of each wavelength component output from the light receiving unit 26 is stored for each channel corresponding to the wavelength. In addition, Fig. 7 shows a case where a signal of 512 channels is output from the light receiving section 26. Figs. The measurement information storage unit 303 stores measurement parameters in each measurement, and typically the value of the gate time (exposure time) of the light receiving unit 26, the value of the storage time corresponding to the measurement period, and the optical filter unit 22. Filter number for specifying the photosensitive rate in &quot;

<Configuration of Information Processing Device>

8 is a schematic block diagram showing a hardware configuration of the information processing apparatus 100 according to the embodiment of the present invention.

Referring to FIG. 8, the computer main body 101 is a CPU (Central Processing Unit) (CPU) connected to each other by a bus in addition to the FD drive unit 111 and the CD-ROM drive unit 113 shown in FIG. 105, a memory 106, a fixed disk 107, and a detector interface (I / F) 109.

The FD 112 can be mounted to the FD drive device 111, and the CD-ROM 114 can be mounted to the CD-ROM drive device 113. As described above, the information processing apparatus 100 according to the present embodiment is realized by the CPU 105 executing a program using computer hardware such as the memory 106. Generally, such a program is stored in a recording medium such as the FD 112 or the CD-ROM 114, or distributed through a network or the like. Such a program is read from the recording medium by the FD drive device 111, the CD-ROM drive device 113, or the like, and is once stored in the fixed disk 107 which is a storage device. It is also read from the fixed disk 107 into the memory 106 and executed by the CPU 105.

The CPU 105 is an arithmetic processing unit that performs various arithmetic by sequentially executing programmed instructions. The memory 106 temporarily stores various types of information in accordance with program execution in the CPU 105.

The detector interface unit 109 is an apparatus for mediating data communication between the computer main body 101 and the detector 2 (FIG. 1), and receives an electrical signal representing measurement data transmitted from the detector 2, thereby receiving a CPU ( 105 is converted into a data format that can be processed, and a command or the like output from the CPU 105 is converted into an electric signal and sent to the detector 2.

The monitor 102 connected to the computer main body 101 is a display device for displaying calculation results such as brightness and color tone of the light emitting object OBJ to be measured calculated by the CPU 105. As an example, LCD (Liquid Crystal) is used. Display) or CRT (Cathode Ray Tube).

The mouse 104 receives a command from the user according to an operation such as a click or a slide. The keyboard 103 receives a command from the user according to the input key.

In addition, other output devices, such as a printer, may be connected to the computer main body 101 as needed.

<Control structure of detector>

9 is a schematic diagram showing a control structure of the controller 30 of the detector 2 according to the embodiment of the present invention.

Referring to FIG. 9, the controller 30 includes a receiver 311, a transmitter 312, a buffer 313, a determiner 314, a filter selector 315, and a setter 316. As a function thereof.

The buffer unit 313 temporarily stores the measured value (spectral distribution) measured by the light receiving unit 26 (FIG. 2).

The determination unit 314 determines the light amount of the measurement light incident on the light receiving unit 26 based on the measurement value stored in the buffer unit 313 to determine whether the filter currently selected by the optical filter unit 22 is appropriate. Evaluate. Specifically, the determination unit 314 determines whether the representative value (for example, the maximum intensity value in each wavelength component) of the measured value stored in the buffer unit 313 exists in a range from a predetermined lower limit value to a predetermined upper limit value. Determine whether or not. When the representative value of the measured value is smaller than the predetermined lower limit value, the determination unit 314 determines that the amount of light of the measurement light incident on the light receiving unit 26 is insufficient, and outputs the message to the filter selection unit 315. On the other hand, when the representative value of the measured value is larger than the predetermined upper limit value, the determination unit 314 determines that the amount of light of the measurement light incident on the light receiving unit 26 is excessive and outputs the message to the filter selection unit 315. .

In addition, when the determination unit 314 determines that the light quantity of the measurement light incident on the light receiving unit 26 is appropriate (between the lower limit and the upper limit), the transmission unit 312 transmits the measured value stored in the buffer unit 313. Will output

In addition, as a representative value of a measured value, you may use the average value, the median value, etc. of each wavelength component. In addition, it is not limited to the method of judging using threshold values, such as an upper limit and a lower limit as mentioned above, What kind of method may be used as long as it can determine whether the light quantity of the measurement light which injects into the light receiving part 26 is appropriate.

In this way, the determination unit 314 determines whether the amount of light of the measurement light that varies depending on the luminance of the light emitter OBJ to be measured is appropriate, and outputs the determination result to the filter selection unit 315 so that an appropriate filter is selected. .

The filter selection unit 315 outputs a filter selection command to the optical filter unit 22 so that an appropriate filter (photosensitive factor) is selected in accordance with the determination result from the determination unit 314. Specifically, when the filter selecting unit 315 determines that the amount of light of the measurement light incident on the light receiving unit 26 is insufficient in the determination unit 314, the filter selecting unit 315 further exposes the measurement light so as to cause more light to be incident on the light receiving unit 26. Outputs the filter selection command for switching to a filter with a small rate. On the other hand, if the filter selection unit 315 determines that the light amount of the measurement light incident on the light receiving unit 26 is excessive in the determination unit 314, the filter having a larger photosensitive ratio is further suppressed so as to suppress the measurement light incident on the light receiving unit 26. Outputs filter selection command to switch to. The filter selector 315 also outputs information (filter number) for specifying the filter currently being selected to the transmitter 312.

In this way, the filter selection unit 315 selects a filter in the optical filter unit 22 so as to maintain the light amount of the measurement light incident on the light receiving unit 26 at a value suitable for the detection sensitivity of the light receiving unit 26.

In addition, the filter selector 315 switches to the designated filter in response to the designation of the filter at the time of calibration sent from the information processing apparatus 100. This is to invalidate the automatic switching function of the filter as described above, since it is necessary to calculate the correction coefficient for each filter included in the optical filter unit 22 during calibration.

The setting unit 316 sets or changes the operating parameters in the light receiving unit 26 in accordance with various settings transmitted from the user input or the information processing apparatus 100 and the like. Specifically, the setting unit 316 sets or changes the exposure time (gate time), the measurement period, and the like of the light receiving unit 26. In addition, the setting unit 316 outputs measurement information including the operation parameters set for the light receiving unit 26 to the transmitting unit 312.

The transmitter 312 creates the measurement data including the measured value measured by the light receiving unit 26 and the set value of the light receiving unit 26 from the setting unit 316, and transmits the measured data to the information processing apparatus 100 at predetermined intervals. do.

The receiver 311 receives filter designations and various settings during calibration from the information processing apparatus 100, and outputs the received setting values to the filter selection unit 315 or the setting unit 316.

<Processing Procedure in the Detector>

Fig. 10 is a flowchart showing a processing procedure in the detector 2 according to the embodiment of the present invention. In addition, the process shown in FIG. 10 is performed by the controller 30 of the detector 2. As shown in FIG.

Referring to Fig. 10, when the power is turned on, the controller 30 causes the optical filter unit 22 to select a filter corresponding to a predetermined initial value (step S100). Then, the controller 30 determines whether or not a measurement start command has been given (step S102). This measurement start instruction is given from the information processing apparatus 100 or the line control apparatus (not shown) which manages a production line, when the light object OBJ of a measurement object arrives at a measurement position. If the measurement start command is not given (NO in step S102), the controller 30 waits until the measurement start command is given.

When a measurement start command is given (YES in step S102), the controller 30 performs measurement of light from the light emitting object OBJ to be measured (step S104). Specifically, reading of the measured value (spectral distribution) detected by the light receiving unit 26 is started.

Subsequently, the controller 30 determines whether the amount of light of the measurement light incident on the light receiving unit 26 is appropriate based on the detected measurement value (step S106). That is, the light receiving part 26 determines whether the representative value of the detected measured value exists in the range from a predetermined lower limit value to an upper limit value.

When it is determined that the light amount of the measurement light incident on the light receiving portion 26 is insufficient (“low” in step S106), that is, when it is determined that the representative value of the measured value is smaller than the predetermined lower limit value, the controller 30 performs the optical filter. In step 22, it is determined whether or not a filter having a smaller photosensitive factor can be selected than the filter currently being selected (step S108).

If it is not possible to select a filter having a light sensitivity smaller than that of the filter currently being selected by the optical filter unit 22 (NO in step S108), the controller 30 outputs a measurement error (step S110), The process returns to step S102. In addition, as a measurement error output, you may transmit the numerical value (for example, negative value) which cannot exist as a measured value to the information processing apparatus 100. FIG.

On the other hand, when it is possible to select a filter whose photosensitive factor is smaller than that of the filter currently being selected by the optical filter unit 22 (in the case of the example in step S108), the controller 30 selects the filter being selected by the optical filter unit 22. Is further switched to a smaller photosensitive rate (step S112), and the processing returns to step S104.

On the other hand, when it is determined that the amount of light of the measurement light incident on the light receiving portion 26 is excessive (“excess” in step S106), that is, when it is determined that the representative value of the measured value is larger than the predetermined upper limit value, the controller 30 In the optical filter unit 22, it is determined whether or not a filter having a larger photosensitive factor can be selected than the filter currently being selected (step S114).

If it is not possible to select a filter having a larger photosensitivity than the filter currently being selected by the optical filter unit 22 (NO in step S114), the controller 30 outputs a measurement error (step S116), The process returns to step S102.

On the other hand, when it is possible to select a filter having a larger photosensitivity than the filter currently being selected by the optical filter unit 22 (in the case of the example in step S114), the controller 30 selects the filter being selected by the optical filter unit 22. Is further switched to a larger photosensitive rate (step S118), and the processing returns to step S104.

When it is determined that the amount of light of the measurement light incident on the light receiving portion 26 is appropriate (YES in step S106), that is, when it is determined that the representative value of the measured value exists in the range of the upper limit from the predetermined lower limit, the controller 30 Transmits the measurement value detected immediately before to the information processing apparatus 100 together with the filter number currently being selected (step S120). After the controller 30 updates the currently selected filter number to a new initial value (step S122), the process returns to step S102. That is, the filter used in the previous measurement is used as the initial value of the next measurement. This is because in a general production line, products are often manufactured in so-called lot units, and after the filter switching is performed at the timing of change of the product type (arbitration position between an arbitrary lot and another lot), the product of the same lot is produced. It is expected to be continuous. Therefore, it is thought that it is preferable to use the filter used for the last measurement as it is for subsequent measurement as it is from a viewpoint of a measurement efficiency.

Thus, the controller 30 switches the photosensitivity in the optical filter part 22 so that the light quantity of the measurement light which injects into the light receiving part 26 becomes suitable, and the measured value detected when the light quantity of the measurement light became appropriate. Is transmitted to the information processing apparatus 100. Therefore, in the information processing apparatus 100, the optical characteristic of the light emitting object OBJ to be measured can be appropriately calculated.

<Control Structure of Information Processing Device>

11 is a schematic diagram showing a control structure in the information processing apparatus 100 according to the embodiment of the present invention.

Referring to Fig. 11, the information processing apparatus 100 includes an operation unit 121 including a correction unit 422 and a calculation unit 123, a calibration control unit 126, a correction coefficient file 124, and a standard. The data file 127 is included as its function. The functions of the calculator 121 and the calibration controller 126 are realized by being executed by the CPU 105 after a program stored in the fixed disk 107 or the like is deployed in the memory 106 in advance. Further, the correction coefficient file 124 and the standard data file 127 are stored in the fixed disk 107 or the nonvolatile region of the memory 106 or the like.

In the correction coefficient file 124, a plurality of correction coefficient tables corresponding to each filter selectable by the optical filter unit 22 of the detector 2 are stored in advance. The plurality of correction coefficient tables can be specified by the filter number. Each correction coefficient table defines the same number of correction coefficients (correction coefficients) as the wavelength components corresponding to the wavelength components included in the measured value (spectral distribution). As an example, when the measurement value includes data of 512 channels, 512 correction coefficients (correction coefficients) are also defined in each correction coefficient table.

The calculating part 121 calculates optical characteristics, such as brightness and chromaticity, of the light emitting object OBJ using the correction coefficient table corresponding to the filter (photosensitive factor) selected by the optical filter part 22 of the detector 2.

More specifically, the correction unit 122 selects a corresponding correction coefficient table from the correction coefficient file 124 based on the filter number included in the measurement data transmitted from the detector 2. The correction unit 122 then calculates the measured value after correction by multiplying each correction coefficient of the selected correction coefficient table by a corresponding component of the measurement value. And the measured value after this correction is provided to the calculating part 123. As shown in FIG.

The calculation unit 123 calculates optical characteristics such as brightness and chromaticity of the light emitter OBJ based on the measured value after the correction. Representative examples of the optical characteristics calculated by the calculator 123 include tristimulus values, chromaticity coordinates, dominant wavelength, stimulus purity, correlated color temperature and deviation (Duv), and color rendering index. These measurement items are mainly defined based on the XYZ colorimeter.

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

As described above, the calculated value (spectral distribution) is required for the calculation of the tristimulus values (X, Y, Z), and the calculation unit 123 adjusts the intensity of each wavelength component in the visible region (380 nm to 780 nm). The value is multiplied by the value of the corresponding orange function. The calculation method of this tristimulus value (X, Y, Z) is prescribed | regulated as JIS Z 8724 "Measurement method of color-light primary color."

12 is a diagram showing an orange color function determined by the International Illumination Commission (CIE). Referring to Fig. 12, the orange color function corresponds to expressing spectral sensitivity in the human eye.

Of the three stimulus values X, Y, and Z, the value of the stimulus value Y is a value corresponding to the brightness of the light emitter OBJ. In the above equation, the constant k is a value in consideration of the detection gain in the light receiving unit 26 and the like, and is set in advance so that the value of "Y" coincides with the absolute value of the brightness actually measured.

In addition, of the three stimulus values X, Y, and Z, the values of the stimulus value X and the stimulus value Y are used to calculate chromaticity coordinates. Chromaticity coordinates (x, y) are calculated according to the following expression.

Chromaticity coordinates (x, y) represent values in the horizontal axis direction and the vertical axis direction of the XYZ color system. The calculation method of this chromaticity coordinate (x, y) is defined as JIS Z 8724 "Measuring method-light source color of color". As a calculation method of chromaticity coordinates, another calculation method is determined also by CIE 1960 UCS or CIE 1976 UCS, and these calculation methods may be used.

In this way, the calculation unit 123 calculates the tristimulus values (X, Y, Z) based on the measured values detected by the detector 2, whereby the brightness kY and chromaticity of the light emitting object OBJ to be measured. At least one of the coordinates (x, y) is calculated. In addition, the calculation unit 123 stores the above-described orange color function and the constant k in advance.

The dominant wavelength corresponds to a wavelength corresponding to the value of the y coordinate of the chromaticity coordinates (x, y) among the chromaticity diagrams defined in the XYZ colorimetric system, and means a difference in the color of the light emitter OBJ. The stimulus purity corresponds to the distance between the coordinates of the origin and the chromaticity coordinates (x, y), and means the density of the color of the light emitter OBJ. The calculation method of this dominant wavelength and magnetic pole purity is prescribed | regulated as JISZ 8701 "Display method of a color-XYZ color system and X10Y10Z10 color system".

The correlated color temperature and the deviation (Duv) refer to the deviation of the temperature of the black body and the temperature of the black body closest to the color of the light emitter OBJ, respectively, as JIS Z 8725 "Method of measuring the distribution temperature of the light source and the color temperature and the correlated color temperature". It is decided.

Color rendering evaluation number evaluates the color rendering property of the light-emitting body OBJ, and is defined as JIS Z 8726 "The color rendering evaluation method of a light source."

<Processing procedure of calculating optical characteristics>

Fig. 13 is a flowchart showing a calculation processing procedure of the optical characteristic 19 in the information processing apparatus 100 according to the embodiment of the present invention. In addition, the process shown in FIG. 13 is typically implemented by the CPU 105 executing a program stored in advance in the fixed disk 107 or the like.

Referring to Fig. 13, the CPU 105 determines whether or not measurement data has been received from the detector 2 (step S200). If the measurement data is not received (NO in step S200), the CPU 105 waits until the measurement data is received.

On the other hand, if the measurement data is received (YES in step S200), the CPU 105 extracts the filter number from the measurement data and reads the correction coefficient table corresponding to the filter number (step S202). The CPU 105 then corrects the measured value by multiplying the measured value contained in the measured data by the correction coefficient table (step S204). Further, the CPU 105 calculates the optical characteristics of the light-emitting body OBJ to be measured as described above on the basis of the measured value after correction (step S206). In addition, the item of the calculated optical characteristic may be selected by a user.

Finally, the CPU 105 outputs the calculated optical characteristics of the light emitter OBJ to be measured to the monitor 102, a printer (not shown), or the like (step S208).

<Update processing sequence of the correction factor table>

Again, with reference to FIG. 11, the correction coefficient table 124 stores the correction coefficient table corresponding to each filter which can be switched in the optical filter part 22 of the detector 2 beforehand. That is, these correction coefficient tables are calculated by calibrating the detector 2. The calibration control unit 126 creates or updates these correction coefficient tables at the time of calibration. Specifically, the calibration control unit 126, upon receiving a calibration instruction from the user or the like, outputs the filter designation during calibration so that a specific filter is selected in the optical filter unit 22 of the detector 2. And the calibration control part 126 compares the measured value obtained by the calibration operation by a user, and the standard spectrum previously stored in the standard data file 127, and creates or updates a correction coefficient table. Below, it demonstrates about (1) energy calibration and (2) wavelength calibration as a calibration process.

(1) energy calibration

The energy calibration is a process for correcting the wavelength dependency of the light receiving sensitivity (gain) in the light receiving portion 26 of the detector 2.

Fig. 14 is a diagram for explaining the procedure when performing energy calibration.

Referring to Fig. 14, a standard lamp 12 is prepared, and a transmission diffusion cap 8 is attached to the light extraction section 6. Then, the distance between the standard lamp 12 and the tip of the transmission diffusion cap 8 is set to a predetermined reference distance (for example, 500 mm). This transmission diffusion cap 8 is a member for making the light irradiated into the light extraction part 6 after making the light irradiated from the standard lamp 12 uniform. The illuminance emitted from the standard lamp 12 is known, and the standard value (spectrum) at the reference distance is previously stored in the standard data file 127 (Fig. 11).

15 is a diagram showing an example of data measured at the time of energy calibration.

Referring to Fig. 15, the energy correction coefficient is calculated as the ratio between the measured value obtained by measuring the standard lamp 12 and the standard value stored in the standard data file 127 in advance. The calibration control unit 126 (FIG. 11) calculates such an energy calibration coefficient for each wavelength component. Further, the correction control unit 126 creates or updates a correction coefficient table corresponding to the filter number being selected by the optical filter unit 22 of the detector 2 at the time based on the calculated energy correction coefficients. Similarly, energy correction is performed by the number of filters selectable in the optical filter unit 22.

Further, since the correction unit 122 (Fig. 11) performs correction by multiplying the measured value by the correction coefficient table, the correction coefficient table is a value corresponding to the reciprocal of the energy correction coefficient shown in Fig. 15.

As described above, the energy calibration needs to be performed as many as the number of filters selectable by the optical filter unit 22 of the detector 2, and it is preferable to carry out at predetermined intervals in consideration of secular variation and the like.

In addition, in the information processing apparatus 100 which concerns on this embodiment, it is not necessary to mount the calibration control part 126 and the standard data file 127, and at the time of calibration, the separate apparatus for calibration is carried out by the detector (2). ), The data of the correction coefficient table calculated by this other apparatus may be stored in the correction coefficient file 124.

(2) wavelength calibration

The wavelength correction is a process for correcting the deviation in the wavelength region of the detection output output from the light receiving section 26.

In the case of performing wavelength calibration, a mercury lamp, a neon lamp, a mercury-neon lamp, etc. which generate | occur | produce light containing many known bright line spectrum are used as a reference light source.

FIG. 16 is a diagram showing a spectrum of light generated from a mercury-neon lamp. FIG. As shown in Fig. 16, the mercury / neon lamp emits light including a large number of bright spectrums, and the difference in the wavelength region is obtained by matching these bright spectrums and the detection outputs output from the light receiving unit 26. Can be corrected.

The correction coefficient file 124 is also stored in the wavelength table which defines the wavelength corresponding to each light receiving element (channel) constituting such a light receiving unit 26. The correction unit 122 (Fig. 11) determines the wavelength corresponding to the detection output of each channel output from the light receiving unit 26 based on this wavelength table. It is also preferable to store the wavelength table for each filter selectable by the optical filter unit 22. In this case, the correction unit 122 performs wavelength correction using a corresponding wavelength table according to the filter selected by the optical filter unit 22.

<First Modification>

In the above-mentioned embodiment, although the structure which switches plural photosensitivity is exemplified by sliding the plate-shaped filter array 202 to the perpendicular direction with respect to the optical axis Ax, what is called a structure using a filter wheel is employ | adopted. You may also

As the structure of the filter wheel, a wheel (original plate) rotatable along a rotation axis parallel to the optical axis Ax is provided, and a plurality of regions having different transmittances from each other are formed in the circumferential direction of the wheel. Then, the wheels are rotated in accordance with the instruction from the controller to switch the photosensitivity by changing the area crossing the optical axis Ax.

Second Modification

In the above-mentioned embodiment, although the optical characteristic measuring apparatus 1 comprised from the separate detector 2 and the information processing apparatus 100 was illustrated, it is the same as the function of the detector 2 and the information processing apparatus 100. FIG. You may comprise as an apparatus.

<Third Modification>

The program according to the present invention may execute a process by calling necessary modules at a predetermined timing in a predetermined arrangement among program modules provided as part of an operating system (OS) of the computer. In that case, the program itself does not contain the module and the processing is executed in cooperation with 0S. Programs that do not include such modules may also be included in the program of the present invention.

In addition, the program which concerns on this invention may be provided integrated in one part of another program. Even in that case, the program itself does not include a module included in the other program, and the processing is executed in cooperation with the other program. Programs assembled with such other programs can also be included in the program of the present invention.

In addition, some or all of the functions realized by the program according to the present invention may be configured by dedicated hardware.

According to this embodiment, measurement is performed after switching the filter arrange | positioned on the optical path of a measurement light so that the light quantity of the measurement light which injects into a light reception part may be a value suitable for the detection sensitivity of the said light reception part. Thereby, even when it applies to the production line which can convey the some kind of light emitting object OBJ from which light emission luminance differs, the optical characteristic of each light emitting body OBJ can be measured suitably. In addition, since the detector according to the present embodiment selects an appropriate filter based on the measured value detected by the light receiving unit, it is possible to easily expand the dynamic range without requiring user operation.

Further, according to the present embodiment, since the photosensitivity can be switched by sliding a plate-shaped filter array in which a plurality of regions having different transmittances are formed in a direction perpendicular to the optical axis of the measurement light, a space for realizing the switching structure is provided. It can be made small and the structure can be simplified.

Further, according to the present embodiment, the plate-shaped filter array is disposed at a predetermined angle other than zero with respect to the number facing the optical axis of the measurement light. By this structure, multiple reflection between a filter array and a diffraction grating which become a factor of a measurement error can be suppressed, and a measurement precision can be improved.

While the invention has been shown and described in detail, it is for the purpose of illustration only and not of limitation, and the scope of the invention will be apparently interpreted by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the external appearance of the optical characteristic measuring apparatus which concerns on embodiment of this invention.

2 is a schematic functional block diagram of a detector according to an embodiment of the present invention.

3 is a perspective view showing the main part structure of a detector according to an embodiment of the present invention;

4 is a configuration diagram of the filter array shown in FIG.

5 is a view for explaining an installation state of a filter array in the optical filter unit according to the embodiment of the present invention.

FIG. 6 is a view for explaining an optical path of return light reflected by the filter array shown in FIG. 5; FIG.

Fig. 7 is a diagram showing an example of the data structure of measurement data transmitted from the detector according to the embodiment of the present invention to the information processing apparatus.

8 is a schematic structural diagram showing a hardware configuration of an information processing apparatus according to an embodiment of the present invention.

9 is a schematic diagram showing a control structure in a controller of a detector according to an embodiment of the present invention.

Fig. 10 is a flowchart showing a processing procedure in the detector according to the embodiment of the present invention.

Fig. 11 is a schematic diagram showing a control structure in the information processing apparatus according to the embodiment of the present invention.

Fig. 12 is a diagram showing an orange color function determined by the International Illumination Commission (CIE).

Fig. 13 is a flowchart showing a procedure for calculating optical characteristics in the information processing apparatus according to the embodiment of the present invention.

Fig. 14 is a diagram for explaining a procedure when performing energy calibration.

15 is a diagram showing an example of data measured at the time of energy calibration.

Fig. 16 is a diagram showing a spectrum of light generated from a mercury / neon lamp.

<Explanation of symbols for the main parts of the drawings>

1: optical characteristic measuring device

2: detector

4 optical fiber

5: transmittance

6: light extraction unit

8: permeation diffusion cap

10: production line

12: standard lamp

20: slit

22: optical filter unit

24: diffraction grating

26: light receiver

28: converter

30: controller

100: information processing device

101: computer body

102: monitor

103: keyboard

104: mouse

106: memory

107: fixed disk

109: detector interface (I / F)

111: FD drive unit

113: CD-ROM drive unit

121: calculation unit

122: correction unit

123: calculating unit

124: correction factor file

126: calibration control

127: standard data file

202: Filter Array

202a, 202b, 202c: area

203: glass substrate

204: movable member

208: Linear Actuator

210: guide member

212: base member

301: storage unit

302: measured value storage unit

303: measurement information storage unit

311: receiving unit

312 transmitter

313: buffer

314: judgment

3l5: Filter selector

316: setting part

OBJ: Light Emitter

Claims (6)

A spectroscopic detector for outputting a signal corresponding to the intensity of each wavelength component included in the light; A light guide unit for guiding light from the light emitting body to the spectroscopic detection unit; An optical filter unit disposed on the light path from the light guide unit to the spectroscopic detection unit and capable of switching a plurality of photosensitivity of transmitted light; And control means for controlling a photosensitive rate in the optical filter unit, The control means judges the amount of light incident on the spectroscopic detection unit on the basis of the signal output from the spectroscopic detection unit. The optical characteristic measuring apparatus which switches a ratio to a smaller value, and switches the photosensitivity in the said optical filter part to a larger value, when the quantity of light which injects into the said spectral detection part is larger than a predetermined upper limit. The apparatus according to claim 1, further comprising computing means for calculating at least one of brightness and chromaticity coordinates of the light emitter based on a signal output from the spectroscopic detector, The calculating means corrects the signal using a correction coefficient corresponding to the reduction ratio selected by the optical filter unit among a plurality of correction coefficients stored in advance corresponding to each of the plurality of reduction ratios in the optical filter unit. Optical property measuring device. The method of claim 2, wherein the optical filter unit, A plate member in which a plurality of regions having different transmittances are formed; And a drive unit for driving the plate-like member in a direction perpendicular to the optical axis of the light incident on the spectroscopic detection unit in accordance with an instruction from the control means. The optical property measuring apparatus according to claim 3, wherein the plate-shaped member is formed by forming a plurality of regions having different transmittances from each other on a common glass substrate. The method of claim 3, wherein the spectroscopic detection unit, A diffraction grating into which light after passing through the optical filter unit is incident; It includes a light receiving unit for receiving the diffracted light generated by the diffraction grating, And the plate-shaped member is disposed at a predetermined angle other than zero with respect to the vertical plane of the optical axis of the light whose plate surface is incident on the diffraction grating. The optical property measuring apparatus according to any one of claims 1 to 5 is configured to sequentially measure a plurality of the light emitters continuously conveyed on a production line, And said control means uses the photosensitivity in said optical filter portion used during the previous measurement as an initial value.

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