KR101548017B1 - Apparatus for measuring optical property - Google Patents

Abstract

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

Optical characteristic measuring device, optical filter part, light receiving part, detector, optical fiber

Description

[0001] APPARATUS FOR MEASURING OPTICAL PROPERTY [0002]

The present invention relates to an optical characteristic measuring apparatus for spectrally measuring light from a light emitting body, and more particularly to a technique for enlarging a measurable luminance range.

BACKGROUND ART [0002] With the recent development of a blue light emitting diode (LED) and the establishment of mass production technology, a white LED that generates light having a wide wavelength band using a blue LED has been put to practical use. This white LED has a high luminous efficiency and realizes a high luminance as compared with a conventional red LED.

However, in the LED production line, there is an inspection step of measuring the brightness or color tone after actually lighting the manufactured LED, and judging whether the product is defective or not. In this inspection step, the measuring device is disposed at a position spaced apart from the LED (light emitting body) to be measured by a predetermined distance, and the defect is judged based on the light measured at the position.

For example, Japanese Patent Application Laid-Open No. 2002-195882 discloses an LED illuminator inspection apparatus comprising an LED sensor unit for detecting light emission to be inspected and determining a light emission state, and a tester controller for performing a final determination. The LED luminous element inspection apparatus detects a plurality of luminance values corresponding to an effective wavelength value of light by using a plurality of optical filters having filter characteristics corresponding to different luminescent colors of the luminous body.

In order to evaluate the color tone of the light emitting body, it is necessary to use a plurality of optical filters as disclosed in Japanese Patent Application Laid-Open No. 2002-195882, : Commission International del'Eclairange), which is the XYZ colorimetric system.

Due to the development of technologies such as high efficiency and large size, the emission luminance of white LEDs is gradually increasing. On the other hand, in a practical production line, a small-sized LED having a relatively low light emission luminance is often produced. Therefore, there is a need to measure LEDs having relatively high light emission luminance and LEDs having relatively low light emission luminance, using the same measuring apparatus. However, there is a case where the difference (ratio) between the light emitting luminance to be measured and the light emitting luminance to be measured becomes larger than the measurable luminance range (dynamic range) in the spectroscopic detection unit. In such a case, it is not possible to measure the optical characteristics of all the luminous bodies while maintaining the same distance between the measuring apparatus and the luminous body (LED) to be inspected. That is, if the distance between the measuring device and the light emitting body to be inspected is relatively increased in order to measure the light emitting body with high light emission luminance, there arises a problem that the measurement accuracy of the light emitting body with low light emission luminance is lowered, If the distance between the measuring device and the illuminant to be inspected is relatively small in order to measure the luminous body, there arises a problem such as an overrange in the spectral detector.

Therefore, a method may be considered in which measurement is performed after changing the distance between the measuring apparatus and the illuminant to be inspected in accordance with the light emission luminance, or measurement is performed in a state in which the luminance is suppressed by reducing the current value or the like applied to the illuminant do. However, with respect to the former method, the re-calibration is required along with the change of the position of the measuring apparatus, and the work becomes more complicated. With respect to the latter method, since the emission characteristic of the light emitting body (LED) is changed by reducing the supply current, the original optical characteristics can not be accurately evaluated.

An object of the present invention is to provide an optical characteristic measuring apparatus capable of easily expanding the dynamic range when spectroscopic measurement of light from a light emitting body is performed.

An optical characteristic measuring apparatus according to one aspect of the present invention includes a spectroscopic detection unit that outputs a signal according to the intensity of each wavelength component included in light, a light guide unit that guides light from the light emitter to the spectroscopic detection unit, An optical filter unit disposed on the optical path to the detection unit and capable of switching the light-sensitive rate of the transmitted light to a plurality of, and control means for controlling the light-sensitive rate in the optical filter unit. The control means judges the amount of light incident on the spectroscopic detection unit based on the signal output from the spectroscopic detection unit, and when the amount of light incident on the spectroscopic detection unit is smaller than the predetermined lower limit value, When the amount of light incident on the spectroscopic detection unit is larger than the predetermined upper limit value, the photosensitivity in the optical filter unit is switched to a larger value.

Preferably, the optical characteristic measuring apparatus further includes calculation means for calculating at least one of brightness and chromaticity coordinates of the light emitting body on the basis of the signal output from the spectroscopic detection unit. The calculating means corrects the signal by using a correction coefficient corresponding to the photosensitivity being selected by the optical filter unit among a plurality of correction coefficients previously stored corresponding to each of the plurality of photospectibilities in the optical filter unit.

Preferably, the optical filter portion includes a plate-shaped member having a plurality of regions having different transmittances from each other, and a drive portion that drives the plate-like member in a direction perpendicular to the optical axis of light incident on the spectroscopic detection portion according to a command from the control means .

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

More preferably, the spectroscopic detection section includes a diffraction grating on which light after passing through the optical filter section is incident, and a light receiving section for receiving diffraction light generated by the diffraction grating. The plate-like member is arranged at a predetermined angle other than 0 with respect to the vertical plane of the optical axis of the light incident on the diffraction grating.

Preferably, the optical characteristic measuring apparatus is configured to sequentially measure a plurality of luminous bodies continuously conveyed on the production line. The control means uses the photosensitivity of the optical filter portion used at the previous measurement as the initial value.

An advantage of the present invention is that the dynamic range can be easily expanded when spectroscopic measurement of light from a light emitting body is made.

These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

According to the present invention, it is possible to provide an optical property measuring apparatus which can easily expand the dynamic range when spectroscopic measurement of light from a light emitting body is performed.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent portions are denoted by the same reference numerals and the description thereof will not be repeated.

<Device Overall Configuration>

1 is a diagram showing an external view of an optical characteristic measuring apparatus 1 according to an embodiment of the present invention.

1, an optical characteristic measuring apparatus 1 according to an embodiment of the present invention typically includes an optical characteristic measuring device 10 for measuring the optical characteristics (e.g., brightness and color tone) of a plurality of luminous bodies OBJ continuously conveyed on a production line 10, . Here, the brightness refers to the luminance or luminous intensity of the luminous body OBJ, and the hue refers to chromaticity coordinates, dominant wavelength, excitation purity, correlated color temperature, etc. of the luminous body OBJ. The optical characteristic measuring apparatus 1 according to the present embodiment can be applied to measurement of a light emitting diode (LED) or a flat panel display (FPD), but in the following description, And a light-emitting body OBJ to be measured are exemplified.

In the production line 10, the luminous body OBJ to be measured is conveyed at a constant speed or intermittently in a predetermined conveying direction, and the optical characteristic measuring apparatus 1 is placed at a predetermined position (measurement position) on the production line 10 The optical characteristics of the light emitting body OBJ are measured. In addition, a power supply device (not shown) is connected to the bottom surface of the LED, which is the light emitting body OBJ, at the measurement position and the immediately preceding position (lighting preparation position), and the LED is turned on. Then, measurement is performed on the LEDs in the turned-on state. In addition, the position where the optical characteristic measuring device 1 is disposed is generally an inspection process before shipment of the LED manufacturing line or during the manufacturing process.

The optical characteristic measuring apparatus 1 includes a detector 2 and an information processing apparatus 100. [ The detector 2 is connected to the light extraction portion 6 disposed above the measurement position of the production line 10 and the like via the optical fiber 4. Then, the optical fiber 4 guides the light from the light emitter OBJ (hereinafter also referred to as &quot; measurement light &quot;) to the detector 2. [

The detector 2 spectroscopically measures the measurement light from the light emitting body OBJ as will be described later, and supplies measurement data including a signal (detection output) corresponding to the intensity of each wavelength component included in the measurement light to the information processing apparatus 100 Output. Particularly, the detector 2 according to the present embodiment includes an optical filter section capable of switching the light-sensitive rate of light passing therethrough to plural as described later, and by appropriately selecting the photosensitivity in the optical filter section, Enlarge the available luminance range (dynamic range). That is, when the luminance from the luminous body OBJ is relatively high, the photosensitivity is set relatively high, and when the luminance from the luminous body OBJ is relatively low, by setting the photosensitivity to be relatively low, A light receiving unit such as a photodiode array for detecting the intensity is used in an appropriate sensitivity range. This makes it possible to maintain appropriate detection accuracy regardless of the luminance of the light emitting body OBJ.

The information processing apparatus 100 calculates the optical characteristic of the light emitting body OBJ based on the measurement data from the detector 2. [ The information processing apparatus 100 is typically realized by a computer. That is, the information processing apparatus 100 includes a computer main body 101 for mounting a flexible disk (FD) drive device 111 and a compact disk-readable memory (CD-ROM) drive device 113, A keyboard 103, and a mouse 104. The keyboard 103 and the mouse 104 are connected to each other. Then, the computer main body 101 executes the program stored in advance, thereby realizing calculation processing of the optical characteristics of the information processing apparatus 100. [ The functional configuration of the 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. Fig. 3 is a perspective view showing a main part structure of the detector 2 according to the embodiment of the present invention.

2, the detector 2 includes a slit 20, a light filter portion 22, a diffraction grating 24, a light receiving portion 26, an AD (analog to digital) converter 28, And a controller 30.

The slit 20, the optical filter section 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-emitting body OBJ propagates through the light extraction portion 6 and the optical fiber 4, and first passes through the slit 20. [ The slit 20 adjusts the luminous flux diameter (size) so as to realize a predetermined detection resolution. As one example, each slit width of the slit 20 is set to about 0.2 mm to about 0.05 mm. Then, the measurement light that has passed through the slit 20 is incident on the optical filter section 22. [ Further, the optical filter portion 22 is disposed at a position substantially coinciding with the convergence position of the measurement light after passing through the slit 20.

The optical filter unit 22 is configured to be capable of switching a plurality of light-sensitive rates of transmitted light. The photosensitivity in the optical filter section 22 is selected in accordance with a command from the controller 30 to be described later.

Further, the measurement light having passed through the optical filter section 22 propagates on the optical axis Ax and enters the diffraction grating 24. The diffraction grating 24 is diffracted by diffracting the measurement light to be incident, and guides each diffracted light to the light receiving portion 26. Typically, the diffraction grating 24 is a reflection type diffraction grating called a Blazed Holographic type, and is configured so that diffracted light for each predetermined wavelength interval is reflected in each corresponding direction.

The light receiving unit 26 detects the intensity of each wavelength component included in the measurement light, and outputs an electric signal (detection output) according to the detected intensity to the AD converter 28. The light receiving section 26 is typically made up of a photodiode array (PDA) in which detecting elements such as photodiodes are arranged in an array, or a CCD (Charged Coupled Device) arranged in a matrix. As an example, the light receiving section 26 outputs a signal according to the intensity of 512 frequency components in the range of 380 nm to 980 nm.

The diffraction grating 24 and the light receiving section 26 correspond to the "spectroscopic detection section" in the present application and are appropriately designed in accordance with the detection wavelength range of the measurement light, the detection wavelength interval, and the like.

Next, the main structure of the detector 2 will be described with reference to Fig. As described above, the slit 20, the optical filter portion 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 unit 22 is disposed on the slit 20 side of the base member 212 such that the movable member 204 is slidable in a direction perpendicular to the optical axis Ax. The movable member 204 is configured to be slidable along the guide member 210 extending in the sliding direction provided on the base member 212. The movable member 204 is connected to the base member 212 through the return spring 206 and is configured to receive the pressure from the linear actuator 208. The return spring 206 gives a force to slide the movable member 204 in the right direction of the paper surface. On the other hand, the linear actuator 208 moves in the sliding direction of the movable member 204 in response to a command from the controller 30 (Fig. 2). The movable member 204 is slid to a position corresponding to the movement amount of the linear actuator 208 by the cooperation of the return spring 206 and the linear actuator 208.

The movable member 204 is formed with a cutout portion including an area intersecting the optical axis Ax along with the slide, and a plate-shaped filter array 202 is attached to the cutout portion. In addition, cutouts (not shown) are formed in the processing range including the optical axis Ax of the base member 212. [ Therefore, only the filter array 202 is a constituent element of the optical filter section 22 existing 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.

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

Referring to Fig. 4, three regions 202a, 202b, and 202c are formed as an example in the filter array 202 according to the present embodiment. As described later, in the detector according to the present invention, a plurality of filters can be selected, and the number of filters is not limited. More specifically, the filter array 202 has regions 202a and 202c on which no processing is performed on the common glass substrate 203 and regions 202b and 202c with different transmittances step by step. Therefore, since the transmittance of the region 202a corresponds to the transmittance of the glass substrate 203 itself and the glass substrate 203 having a relatively high transmittance is used in the present embodiment, the photosensitivity of the region 202a is substantially 0 . On the other hand, the regions 202b and 202b are processed to have, for example, a transmittance of 5% (ND5) and a transmittance of 0.2% (ND 0.2), respectively. Therefore, the photosensitivity of the regions 202b and 202b is 1/20 and 1/500, respectively.

3, the movable member 204 to which the filter array 202 is attached slides in a direction perpendicular to the optical axis Ax, so that the areas 202a, 202b, and 202c formed in the filter array 202 The area intersecting the optical axis Ax is switched. That is, depending on which area of the area 202a, 202b, or 202c the measurement light passes through, the photosensitivity can be made different.

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 one of the regions 202a, 202b, and 202c is selected, at least the measurement light passes through the glass substrate 203. [ Therefore, by making the thickness of the glass substrate 203 larger than the processing width for realizing the predetermined transmittance, it is possible to reduce the fluctuation of the optical path length of the measurement light caused by the switching of the photosensitivity.

In addition, since the photosensitivity can be switched only by sliding the filter array 202 formed by the common glass substrate 203, the space for realizing the switching structure can be reduced.

It is also preferable to dispose the filter array 202 at a predetermined angle other than 0 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 direction opposite to the measurement light and enters the filter array 202 and is reflected by the filter array 202 to be reflected by the diffraction grating 24 ). As described above, a part of the measurement light is multiplexed and reflected between the filter array 202 and the diffraction grating 24, so that a measurement error may occur. In order to eliminate such an error factor, it is effective to make the direction in which the measurement light reflected by the diffraction grating 24 and reflected by the filter array 202 of the return light deviate from the optical axis Ax.

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

Referring to Fig. 5, the movable member 204 is arranged such that its plate surface substantially coincides with the vertical plane of the optical axis Ax of the measurement light. The filter array 202 is maintained at a predetermined angle?, Not 0, with respect to the plane of the movable member 204, that is, the vertical plane of the optical axis Ax.

6 shows optical paths of the measurement light viewed in the horizontal direction and the return light generated by the measurement light. The measurement light incident on the diffraction grating 24 is diffracted by the diffraction grating 24 so that a part of the diffracted light (multiple light) propagates in the opposite direction to the optical axis Ax as return light, I will join. By arranging the filter array 202 at a predetermined angle?, Among the return light incident on the filter array 202, components reflected by the filter array 202 are separated from the optical axis Ax by a predetermined angle? Propagates in different directions. As a result, it is possible to suppress the return light reflected by the filter array 202 from re-entering into the diffraction grating 24.

The predetermined angle? Is calculated based on the distance between the filter array 202 and the diffraction grating 24 and the focal length of the diffraction grating 24, Is set at an appropriate angle so as not to be re-incident on the light source (24). In reality, it is preferably about 5 to 15 degrees.

5, since the filter array 202 is configured to maintain a predetermined inclination angle about the slide axis of the movable member 204, even when any one of the filter arrays 202 is selected, 202 and the optical axis Ax is maintained. Therefore, regardless of the filter to be selected, the conditions of the measurement light incident on the diffraction grating 24 can be the same, and the occurrence of errors caused by the filter switching can be suppressed.

Since the filter array is in the form of a plate, when the filter array 202 is mounted on the movable member 204, a single process (typically, a counterbore <counterbore> (concave) portion is formed) It can be simplified.

5 and 6 illustrate the configuration in which the filter array 202 is inclined with respect to the bottom side thereof, that is, the configuration in which the filter array 202 is inclined in the vertical direction of the paper surface. However, That is, in the left-right direction of the paper surface. Essentially, multiple reflections between the filter array 202 and the diffraction grating 24 need only be avoided.

2, the AD converter 28 converts an electric signal from the light receiving unit 26 into a digital signal, and outputs the digital signal after the conversion to the controller 30. [

The controller 30 is configured to be capable of communicating data with the information processing apparatus 100 (Fig. 1), and controls the switching of the photosensitivity in the optical filter unit 22 as described later. Further, the controller 30 sets the operation parameters such as the exposure time (gate time) of the light receiving unit 26 and the like. The controller 30 then transmits the measurement data including the detection output detected by the light receiving unit 26 to the information processing apparatus 100 at predetermined intervals when the switching of the photosensitivity in the optical filter unit 22 is completed . The transmission period of the measurement data is several msec to several hundreds msec.

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

Referring to FIG. 7, the data structure of measurement data transmitted every 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 an ID number for specifying each measurement. This ID number is typically a number that increases with the measurement. In the measured value storage unit 302, a value indicating the intensity of each wavelength component output from the light receiving unit 26 is stored for each channel corresponding to the wavelength. 7 shows a case in which a signal of 512 channels is outputted from the light-receiving unit 26. In FIG. The measurement information storage unit 303 stores measurement parameters for each measurement and typically includes values of the gate time (exposure time) of the light receiving unit 26, the value of the storage time corresponding to the measurement period, And a filter number for specifying the photosensitivity in the photodetector.

<Configuration of Information Processing Apparatus>

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

8, in addition to the FD drive unit 111 and the CD-ROM drive unit 113 shown in Fig. 1, the computer main body 101 includes a CPU (Central Processing Unit) 105, a memory 106, a fixed disk 107, and a detector interface (I / F)

The FD drive unit 111 can be loaded with the FD 112 and the CD-ROM drive unit 113 can be loaded with the CD-ROM 114. 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 unit 111, the CD-ROM drive unit 113, or the like, and temporarily stored in the fixed disk 107 as a storage device. And is read out from the fixed disk 107 to the memory 106 and executed by the CPU 105. [

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

The detector interface 109 is a device for mediating data communication between the computer main body 101 and the detector 2 (FIG. 1) and receives an electrical signal indicative of the measurement data transmitted from the detector 2, 105 are converted into a data format that can be processed, and at the same time, a command or the like outputted from the CPU 105 is converted into an electrical signal and sent to the detector 2.

The monitor 102 connected to the computer main body 101 is a display device for displaying the result of calculation such as the brightness or color tone of the illuminant OBJ to be measured and calculated by the CPU 105. For example, Display) or CRT (Cathode Ray Tube).

The mouse 104 accepts a command from the user in response to an operation such as clicking or sliding. The keyboard 103 receives a command from the user according to the input key.

Other output devices such as a printer may be connected to the computer main body 101, if necessary.

<Control Structure of Detector>

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

9, the controller 30 includes a receiving unit 311, a transmitting unit 312, a buffer unit 313, a judging unit 314, a filter selecting unit 315, a setting unit 316, As its function.

The buffer unit 313 temporarily stores measured values (spectral distributions) measured at the light receiving unit 26 (Fig. 2).

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

When the light amount of the measuring light incident on the light receiving unit 26 is judged to be appropriate (between the lower limit value and the upper limit value), the judging unit 314 transmits the measured value stored in the buffer unit 313 to the transmitting unit 312, .

As a representative value of the measured value, an average value or an intermediate value of each wavelength component may be used. Any method may be used as long as it can determine whether or not the light amount of the measurement light incident on the light receiving section 26 is appropriate, as described above, without being limited to the method of determining by using the threshold value such as the upper limit value and the lower limit value.

In this way, the determination unit 314 determines whether the light amount of the measurement light that varies depending on the luminance of the luminous body 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 rate) is selected according to the determination result from the determination unit 314. [ More specifically, when it is determined by the determination unit 314 that the light amount of the measurement light incident on the light-receiving unit 26 is insufficient, the filter selection unit 315 selects the light- And outputs a filter selection command for switching to a filter having a small rate. On the other hand, when the determination unit 314 determines that the amount of the measurement light incident on the light receiving unit 26 is excessive, the filter selection unit 315 selects the filter having a larger light- And outputs a filter selection command for switching to the filter selection command. Further, the filter selection unit 315 outputs information (filter number) for specifying the currently selected filter to the transmission unit 312.

The filter selecting unit 315 selects the filter in the optical filter unit 22 so as to keep 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. [

Further, the filter selection unit 315 switches to the designated filter in response to the filter designation at the time of calibration sent from the information processing apparatus 100. [ This is for the purpose of invalidating the automatic switching function of the filter as described above because it is necessary to calculate the correction coefficient for each filter included in the optical filter unit 22 at the time of calibration.

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

The transmitting unit 312 generates measurement data including the measurement value measured at the light receiving unit 26 and the setting 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 receiving unit 311 receives filter setting and various settings at the time of calibration from the information processing apparatus 100 and outputs the received setting values to the filter selecting unit 315 and the setting unit 316. [

&Lt; Sequence of Processing in Detector >

10 is a flowchart showing a processing procedure in the detector 2 according to the embodiment of the present invention. The processing shown in Fig. 10 is executed by the controller 30 of the detector 2. Fig.

Referring to Fig. 10, when the power is turned on, the controller 30 selects a filter corresponding to a predetermined initial value for the optical filter unit 22 (step S100). Then, the controller 30 determines whether or not a measurement start command is given (step S102). This measurement start command is given from a line control device (not shown) that manages the information processing apparatus 100 and the production line when the luminous object OBJ to be measured arrives at the measurement position. If the measurement start command is not given (NO in step S102), the controller 30 waits until a 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 body OBJ to be measured (step S104). More specifically, the reading of the measured value (spectral distribution) detected by the light receiving section 26 is started.

Subsequently, the controller 30 determines whether or not the light amount of the measurement light incident on the light receiving section 26 is appropriate based on the detected measurement value (step S106). That is, the light receiving unit 26 determines whether or not the representative value of the detected measurement value falls within a range from a predetermined lower limit value to an upper limit value.

If it is determined that the light amount of the measurement light incident on the light receiving section 26 is insufficient ("shortage" in step S106), that is, if it is determined that the representative value of the measured value is smaller than the predetermined lower limit value, It is determined whether or not a filter having a smaller photosensitivity than the currently selected filter can be selected (step S108).

In the case where the filter whose light-sensitive ratio is smaller than the filter currently selected by the optical filter unit 22 can not be selected (NO in step S108), the controller 30 outputs a measurement error (step S110) The process returns to step S102. As the measurement error output, a numerical value (for example, a minus value) that can not be a measurement value may be transmitted to the information processing apparatus 100.

On the other hand, when it is possible to select a filter having a lower photosensitivity than the currently selected filter in the optical filter section 22 (in the case of the example in step S108), the controller 30 controls the filter (Step S112), and the process returns to step S104.

On the other hand, when it is determined that the light amount of the measurement light incident on the light receiving section 26 is excessive (&quot; excessive &quot; 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, It is determined whether or not a filter having a higher photosensitivity than the currently selected filter can be selected in the optical filter unit 22 (step S114).

In a case where the filter whose light-sensitive ratio is larger than the filter currently selected by the optical filter unit 22 can not be selected (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 higher photosensitivity than the currently selected filter in the optical filter section 22 (in the case of the example in step S114), the controller 30 controls the filter (Step S118), and the process returns to step S104.

When it is determined that the light amount of the measurement light incident on the light receiving section 26 is appropriate (YES in step S106), that is, when it is determined that the representative value of the measured value is within the range from the predetermined lower limit value, Together with the currently selected filter number, the immediately preceding measurement value to the information processing apparatus 100 (step S120). Then, the controller 30 updates the currently selected filter number to a new initial value (step S122), and 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, a product is often produced in a so-called lot unit, and after the filter switching is performed at the change timing of the product type (boundary between arbitrary lot and another lot) It is expected to be continuous. This is because it is considered preferable to use the filter used in the previous measurement as it is for the subsequent measurement from the viewpoint of measurement efficiency.

As described above, the controller 30 switches the photosensitivity of the light filter section 22 so that the light quantity of the measurement light incident on the light receiving section 26 becomes appropriate, and when the light quantity of the measurement light becomes appropriate, To the information processing apparatus (100). Thus, the information processing apparatus 100 can appropriately calculate the optical characteristic of the light emitting body OBJ to be measured.

<Control Structure of Information Processing Apparatus>

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

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 includes the data file 127 as its function. The functions of the arithmetic unit 121 and the calibration control unit 126 are realized by the CPU 105 executing the program stored in the fixed disk 107 or the like in advance in the memory 106. [ The correction coefficient file 124 and the standard data file 127 are also stored in the nonvolatile area of the fixed disk 107 or the memory 106 or the like.

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

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

More specifically, the corrector 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. [ Then, the corrector 122 multiplies each of the correction coefficients of the selected correction coefficient table by the corresponding component of the measured value, thereby calculating the corrected measured value. The measurement value after the correction is given to the calculation unit 123. [

The calculating unit 123 calculates the optical characteristics such as the brightness and chromaticity of the light emitting unit OBJ based on the measured values after the correction. Typical examples of the optical characteristics calculated by the calculation unit 123 include a tristimulus value, a chromaticity coordinate, a dominant wavelength, a stimulus purity, a correlated color temperature and a deviation (Duv), and the number of color rendering evaluations. These metrics are mainly defined on the basis of the XYZ color system.

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

As described above, the calculation of the tristimulus values (X, Y, Z) requires a measurement value (spectral distribution), and the calculation section 123 calculates the intensity of each wavelength component in the visible region (380 nm to 780 nm) And integrates the value obtained by multiplying the value of the corresponding color matching function. The method of calculating the three-pole value (X, Y, Z) is defined as JIS Z 8724 "Measurement method of color - light source color".

Figure 12 is a diagram showing the color matching function defined by the International Lighting Commission (CIE). Referring to Fig. 12, the color matching function corresponds to the expression of spectral sensitivity in human eyes.

Of the three stimulus values (X, Y, 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 portion 26 or the like, and is set in advance so that the value of "Y" coincides with the absolute value of the actually measured brightness.

Of the three-pole values (X, Y, Z), the values of the pole value X and the pole value Y are used to calculate the chromaticity coordinates. The chromaticity coordinate (x, y) is calculated according to the following equation.

The chromaticity coordinate (x, y) indicates the value in the horizontal axis direction and the value in the vertical axis direction of the XYZ color system. The method of calculating the chromaticity coordinate (x, y) is defined as JIS Z 8724 "Measurement method of color - light source color". As the chromaticity coordinate calculation method, other calculation methods are also determined by CIE 1960 UCS or CIE 1976 UCS, and these calculation methods may be used.

In this way, the calculating unit 123 calculates the three-pole value (X, Y, Z) based on the measured value detected by the detector 2 to calculate the brightness (kY) and chromaticity And calculates at least one of the coordinates (x, y). In addition, the calculation unit 123 stores in advance the above-mentioned color matching function and integer k.

The dominant wavelength corresponds to the wavelength corresponding to the y coordinate value of the chromaticity coordinate (x, y) among chromaticity degrees defined in the XYZ color system, and means a difference in color of the light emitting body OBJ. The excitation purity corresponds to the distance between the coordinates of the origin and the chromaticity coordinates (x, y) and means the concentration of the color of the luminous body OBJ. The main wavelength and the method of calculating the purity of the stimulus are defined as JIS Z 8701 "Color display method-XYZ color system and X10Y10Z10 color system".

The correlated color temperature and the deviation Duv mean deviations with respect to the temperature of the black body and the temperature of the black body closest to the colors of the luminous body OBJ and are measured in accordance with JIS Z 8725 "Method of measuring the distribution temperature and color temperature and correlated color temperature of a light source" It is fixed.

The color rendering index is used to evaluate the color rendering property of the luminous body OBJ and is defined as JIS Z 8726 &quot; method for evaluating the color rendering property of a light source &quot;.

&Lt; Procedure for calculating optical characteristics >

Fig. 13 is a flowchart showing the procedure of calculating the optical characteristics 19 in the information processing apparatus 100 according to the embodiment of the present invention. 13. The processing shown in Fig. 13 is typically realized 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 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 it receives the measurement data.

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). Then, the CPU 105 corrects the measurement value by multiplying the measurement value included in the measurement data by the correction coefficient table (step S204). Further, the CPU 105 calculates the optical characteristics of the luminous body OBJ to be measured as described above based on the corrected measured values (step S206). The item of the calculated optical characteristic may be selected by the user.

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

&Lt; Procedure for updating correction coefficient table >

11, a correction coefficient table corresponding to each switchable filter in the optical filter unit 22 of the detector 2 is stored in advance in the correction coefficient file 124. [ In other words, 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 outputs a filter designation upon calibration so that a specific filter is selected in the optical filter unit 22 of the detector 2 when receiving a calibration command from a user or the like. The calibration control unit 126 compares the measured value obtained by the user's calibration operation with the standard spectrum stored in advance in the standard data file 127 to create or update the correction coefficient table. Hereinafter, as the calibration processing, (1) energy calibration and (2) wavelength calibration are exemplified.

(1) Energy calibration

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

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

14, the standard lamp 12 is prepared, and at the same time, the transmission diffusion cap 8 is mounted on the light extraction portion 6. Then, the distance between the standard lamp 12 and the distal end of the transmission diffusion cap 8 is set to a predetermined reference distance (for example, 500 mm). The transmission diffusion cap 8 is a member for making the light emitted from the standard lamp 12 uniform and then entering the light extraction portion 6. [ The illuminance radiated from the standard lamp 12 is known and a standard value (spectrum) in the standard distance is stored in advance 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 a ratio between a measurement value obtained by measuring the standard lamp 12 and a standard value stored in advance in the standard data file 127. The calibration control unit 126 (Fig. 11) calculates such an energy correction coefficient for each wavelength component. Further, the calibration control unit 126 creates or updates a correction coefficient table corresponding to the filter number selected by the optical filter unit 22 of the detector 2 at that time, based on the calculated energy correction coefficient. Similarly, energy correction is performed by the number of filters that can be selected by the optical filter unit 22. [

11) performs correction by multiplying the measured value by the correction coefficient table, so that the correction coefficient table becomes a value corresponding to the inverse number of the energy correction coefficients shown in Fig.

The energy calibration as described above needs to be performed for the number of filters that can be selected by the optical filter unit 22 of the detector 2, and it is preferable that the energy calibration is performed at predetermined intervals in consideration of aging or the like.

In the information processing apparatus 100 according to the present embodiment, the calibration control unit 126 and the standard data file 127 need not necessarily be installed. When calibration is performed, a separate calibration device is connected to the detector 2 , And the data of the correction coefficient table calculated by this separate apparatus may be stored in the correction coefficient file 124. [

(2) Wavelength correction

The wavelength calibration is a process for correcting the deviation in the wavelength range of the detection output from the light receiving unit 26. [

In the case of performing wavelength calibration, a mercury lamp, a neon lamp, a mercury / neon lamp, or the like is used as a reference light source for generating light including a plurality of known luminance spectra.

16 is a view showing a spectrum of light generated from a mercury-neon lamp. As shown in Fig. 16, light including a plurality of bright line spectra is emitted from the mercury / neon lamp. By matching these bright line spectra with the detection output outputted from the light receiving unit 26, the difference in the wavelength range Can be corrected.

The wavelength table that defines the wavelength corresponding to each light receiving element (channel) constituting the light receiving section 26 is also stored in the correction coefficient file 124. [ 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 that can be selected by the optical filter unit 22. [ In this case, the corrector 122 performs wavelength calibration using the corresponding wavelength table in accordance with the filter selected by the optical filter unit 22. [

<First Modification>

In the above-described embodiment, the configuration in which the plate-like filter array 202 is slid in the direction perpendicular to the optical axis Ax so as to switch the photosensitivity to a plurality of photosensors has been exemplified, but a configuration using a so- You can.

As the structure of the filter wheel, a wheel (disc) rotatable along a rotation axis parallel to the optical axis Ax is provided, and a plurality of regions having different transmittances are formed in the circumferential direction of the wheel. The photosensitivity is switched by rotating the wheel in response to a command from the controller to change the region crossing the optical axis Ax.

&Lt; Second Modified Example &

The optical characteristic measuring apparatus 1 including the detector 2 and the information processing apparatus 100 which are separate from each other has been described as an example of the optical characteristic measuring apparatus 1. However, Or may be configured as an apparatus.

&Lt; Third Modified Example &

The program according to the present invention may be a program for causing a computer to perform a process by calling necessary modules from a program module provided as a part of an operating system (OS) of a computer at a predetermined timing in a predetermined arrangement. In this case, the program itself does not include the module, and processing is executed in cooperation with OS. A program not including such a module may also be included in the program according to the present invention.

The program according to the present invention may be provided in a part of another program. In this case, the program itself does not include a module included in the other program, but executes processing in cooperation with another program. Such a program assembled into another program may also be included in the program according to the present invention.

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

According to the present embodiment, the measurement is performed after the filter arranged on the optical path of the measurement light is switched so that the light amount of the measurement light incident on the light reception unit becomes a value suitable for the detection sensitivity of the light reception unit. Thus, even when the present invention is applied to a production line capable of transporting a plurality of kinds of luminous bodies OBJ having different luminous intensities, the optical characteristics of each luminous body OBJ can be suitably measured. Further, since the detector according to the present embodiment selects an appropriate filter based on the measured value detected by the light receiving unit, the dynamic range can be easily enlarged without requiring any user operation.

According to the present embodiment, since the photosensitive rate can be switched by sliding the plate-like filter array in which a plurality of regions having different transmittances are formed, in the direction perpendicular to the optical axis of the measurement light, And the structure can be simplified.

Further, according to the present embodiment, the plate-like filter array is arranged at a predetermined angle other than 0 with respect to the water surface of the optical axis of the measurement light. With this arrangement, it is possible to suppress multiple reflections between the filter array and the diffraction grating, which are factors of the measurement error, and increase the measurement accuracy.

Although the present invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example only, and the scope of the invention is to be construed according to the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing an external view of an optical property measuring apparatus according to an embodiment of the present invention. Fig.

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

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

Fig. 4 is a configuration diagram of the filter array shown in Fig. 3; Fig.

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

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

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

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

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

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

Figure 12 shows an isochromatic function defined by the International Lighting Commission (CIE);

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

14 is a diagram for explaining a procedure when energy calibration is performed;

Fig. 15 is a view showing an example of data measured at the time of energy calibration; Fig.

16 is a view showing a spectrum of light generated from a mercury / neon lamp;

Description of the Related Art

1: Optical property measuring device

2: detector

4: Optical fiber

5: transmittance

6:

8: Transmission diffusion cap

10: Production line

12: Standard lamp

20: slit

22:

24: diffraction grating

26:

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 device

113: CD-ROM drive device

121:

122:

123:

124: correction factor file

126: Calibration control section

127: Standard data file

202: filter array

202a, 202b, 202c:

203: glass substrate

204: movable member

208: Linear actuator

210: guide member

212: Base member

301:

302: Measurement value storage unit

303: Measurement information storage unit

311:

312:

313:

314:

3L5:

316: Setting section

OBJ: luminous body

Claims (6)

An optical property measuring apparatus comprising: A spectroscopic detector for outputting a signal according to the intensity of each wavelength component included in the light; A light guide portion for guiding light from the light emitting body to the spectroscopic detection portion, An optical filter unit including a plate-like member disposed on a light path from the light guide unit to the spectroscopic detection unit and having a plurality of regions having different transmittances from each other and capable of switching the photosensitivity of the transmitted light to a plurality of, And control means for controlling a light-sensitive rate in the optical filter unit, Wherein the control unit determines the amount of light incident on the spectroscopic detection unit based on a signal output from the spectroscopic detection unit, and when the amount of light incident on the spectroscopic detection unit is smaller than a predetermined lower limit value, And when the amount of light incident on the spectroscopic detection unit is larger than a predetermined upper limit value, the photosensitivity of the optical filter unit is switched to a larger value, Wherein the spectroscopic detection unit comprises: A diffraction grating on which light after passing through the optical filter portion is incident, And a light receiving portion for receiving diffracted light generated by the diffraction grating, Wherein the plate-like member is disposed at a predetermined angle other than 0 with respect to a vertical plane of an optical axis of light incident on the diffraction grating. The apparatus according to claim 1, further comprising calculating means for calculating at least one of brightness and chromaticity coordinates of the illuminant based on a signal output from the spectral detector, Wherein the calculating means corrects the signal by using a correction coefficient corresponding to the photosensitivity being selected by the optical filter unit among a plurality of correction coefficients previously stored corresponding to each of the plurality of photospectibilities in the optical filter unit Optical property measuring device. The optical filter according to claim 2, And a driving unit for driving the plate-like member in a direction perpendicular to an optical axis of light incident on the spectroscopic detection unit, in accordance with a command from the control unit. The optical property measuring apparatus according to claim 3, wherein the plate-like members are formed by forming a plurality of regions having different transmittances from each other on a common glass substrate. The optical characteristic measuring apparatus according to any one of claims 1 to 4, wherein the optical characteristic measuring device is configured to sequentially measure a plurality of the luminous bodies continuously conveyed on a production line, Wherein said control means uses, as an initial value, a photosensitivity in said optical filter section used in a previous measurement. delete

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