JP5743189B2 - Optical measuring apparatus and optical measuring method - Google Patents

Description

  The present invention relates to an optical measurement apparatus and an optical measurement method for receiving light emitted from an illumination light source and performing optical measurement of the illumination light source.

  Optical characteristics of an illumination light source such as an LED are measured using a spectrometer. The spectrometer splits the light emitted from the illumination light source and receives the split light to detect the spectrum. The optical measurement of the LED is performed using the detected spectrum. Specifically, the optical characteristics of the LED are measured by calculating values such as tristimulus values, chromaticity coordinates, luminous flux, radiant flux, dominant wavelength, peak wavelength, full width at half maximum based on the detected spectrum. .

  A technique of performing optical measurement using a spectrometer is disclosed in Patent Document 1, and a technique of supplying current from a power supply unit to an LED to emit light is disclosed in Patent Document 2. FIG. 10 shows an example of a conventional measurement system that performs optical measurement of LEDs using a spectrometer. The measurement system 101 includes a power supply unit 102, an LED 103, an integrating sphere 104, an optical fiber 105, a photometric unit 106, and a computer 107.

  The power supply unit 102 outputs a drive current to the LED 103 when the value of the drive current is set by the computer 107. The LED 103 emits light L when a drive current is supplied. The light L enters the integrating sphere 104 and is guided to the optical fiber 105. Then, the light L guided by the optical fiber 105 enters the photometry unit 106.

  The photometry unit 106 includes an optical unit 111, an AD conversion unit 112, and a signal processing unit 113, and spectrums the light L to detect a spectrum. The optical unit 111 includes a spectroscopic unit 114 and a detection unit 115. The spectroscopic unit 114 splits the light L guided from the optical fiber 105. The detection unit 115 receives the dispersed light L, performs photoelectric conversion, and outputs an electrical signal (optical unit output).

  The AD converter 112 receives this electric signal and converts it from an analog signal to a digital signal. The signal processing unit 113 receives the converted digital signal and generates an intensity distribution value (spectral data) on the wavelength axis. Then, the generated spectrum data is transferred to the computer 107.

  The computer 107 sets the value of the drive current for the power supply unit 102 and performs a predetermined calculation (calculation of the tristimulus values described above) based on the spectrum data transferred from the signal processing unit 113 of the photometry unit 106. . By performing this calculation, optical measurement of the LED 103 is performed. The measurement result is displayed on a display means (display or the like) connected to the computer 107, for example.

  FIG. 11 shows the timing in the configuration of FIG. The LED 103 emits light while a driving current is supplied from the power supply unit 102. The time during which the LED 103 emits the light L is defined as a light emission time ET. The light L emitted from the LED 103 is incident on the photometry unit 106 via the integrating sphere 104 and the optical fiber 105. Then, the light L is split by the spectroscopic unit 114, and the light L is detected by the detection unit 115.

  The signal processing unit 113 controls the timing of reading the electrical signal from the detection unit 115, and the electrical signal is read from the detection unit 115 to the AD conversion unit 112 when reading is started. Then, the AD conversion unit 112 converts the analog signal into a digital signal, and performs an operation for obtaining spectrum data. Then, after the spectrum data is generated, the spectrum data is transferred to the computer 107.

  As shown in the figure, the photometry unit 106 measures the light L (photometry) at regular intervals (photometry cycle CT). Thus, optical measurement of the LED 103 is performed by repeatedly performing photometry for each photometry cycle CT. Photometry is performed based on the light L received during a certain time (photometry time MT). Therefore, optical measurement is performed by measuring the light L only during the photometric time MT for each photometric period CT.

JP 2009-288150 A JP 2009-076381 A

  The optical measurement of the LED 103 is performed based on the light L received during the photometric time MT. Therefore, the photometric time MT must receive all the light L emitted from the LED 103. If the light L is not received by the photometry unit 106 during the photometry time MT, the light L detected by the detection unit 115 becomes inaccurate. Therefore, it is necessary to completely receive the light L at least during the photometric time MT.

  On the other hand, the photometry unit 106 and the power supply unit 102 are simply connected to the computer 107, and the photometry unit 106 and the power supply unit 102 operate independently. That is, the power supply unit 102 causes the LED 103 to emit light uniquely, and the photometry unit 106 measures the light L independently.

  Accordingly, since the LED 103 and the photometry unit 106 operate independently of each other, a deviation may occur between the light emission timing of the LED 103 and the photometry timing of the photometry unit 106. Due to this timing shift, the light L is not received by the detector 115 during the photometric time MT of the photometer 106. For this reason, the measurement result is inaccurate.

  For this reason, the light emission time ET of the LED 103 is made sufficiently long. If the light emission time ET is ensured sufficiently long, the problem that the light L is not received during the photometric time MT can be avoided even if a timing shift occurs. Specifically, by making the light emission time ET longer (ET> MT + CT) than the time obtained by adding the photometric period CT and the photometric time MT, the light L can be reliably received during the photometric time MT.

  At this time, the LED 103 rises in temperature in the chip over time from the start of light emission, and the spectral characteristics of the emitted light L change due to this temperature rise. Therefore, as the light emission time ET of the LED 103 becomes longer, the temperature rise also increases and the fluctuation of the spectral characteristics also increases. If the fluctuation of the spectral characteristics becomes indefinite, the accuracy of the optical measurement of the LED 103 decreases.

  That is, since the light emission timing and the photometry timing are respectively unique, the time from the start of light emission of the LED 103 to the detection of the light L by the detection unit 115 changes for each measurement. As described above, since photometry is repeatedly performed for each photometry cycle CT, the fluctuation range of the spectrum characteristic changes with each photometry. As a result, optical measurement cannot be performed with a certain reproducibility, and the accuracy of the measurement result is lost.

  Further, by making the light emission time ET of the LED 103 sufficiently long, the light L is reliably received during the entire photometric time MT. When the light emission time ET of the LED 103 becomes longer, extremely high heat generation occurs. Thereby, a big thermal stress is given with respect to LED103, and a damage becomes large. In particular, when the LED 103 is used for illumination or the like, the rated current of the power supply unit 102 is increased, and the LED 103 has a high output. At this time, if the light emission time ET of the LED 103 is set to a long time, a large thermal stress acts on the LED 103, and the damage given thereto increases.

  Therefore, an object of the present invention is to accurately perform optical measurement without receiving heat damage to the illumination light source when receiving light emitted from the illumination light source and performing optical measurement.

In order to solve the above-described problems, an optical measurement apparatus according to the present invention receives a light emitting unit that emits light from the illumination light source when a power source supplies a driving current to the illumination light source, and receives light emitted from the illumination light source. A triggering signal for synchronizing the light emission timing of the light emitting unit and the measurement timing of the photometric unit by connecting the light measuring unit that performs optical measurement of the illumination light source, and the light emitting unit and the photometric unit. a trigger signal transmitting unit that transmits the measurement as at the end of the measurement of the optical unit is delayed by a predetermined time than the time the supply end of the driving current in the light-emitting unit, a timing control for controlling on the basis of the trigger signal And a section.

  This optical measuring device synchronizes the light emitting unit and the photometric unit by directly connecting the light emitting unit and the photometric unit to transmit a trigger signal. Thereby, the light emission timing and the photometry timing are synchronized so as not to cause a timing shift. Therefore, accurate optical measurement can be performed, and heat damage to the illumination light source can be reduced.

  In addition, the light emitting unit includes a current detection unit that transmits the trigger signal to the photometry unit when it detects that the driving current flows in a current path connecting the power source unit and the illumination light source. It is characterized by having. By detecting that a current has flowed in the current path and using this as a trigger signal, the light emission timing and photometry timing can be synchronized by simply adding simple components without changing the configuration of the power supply unit Can do.

  Further, the power supply unit includes a trigger output unit that outputs the trigger signal to the photometry unit when the output of the drive current to the illumination light source is started. By providing a trigger output unit in the power supply unit and outputting a trigger signal, the light emission timing and the photometry timing can be synchronized.

  In addition, the light source includes a plurality of light metering units that measure the light emitted from the illumination light source at different wavelengths, and outputs the trigger signal to all the light metering units to emit the light. The light emission timing of each unit is synchronized with the measurement timings of all the photometry units. By outputting trigger signals from the light emitting units to all the photometric units, the light emission timing and the photometric timings of all the photometric units can be synchronized.

  Further, shutter means for controlling the photometry to make the light emitted from the light emitting unit incident on the photometry unit only during the time when the photometry unit performs measurement, and to prevent the light from entering the photometry unit at times other than the measurement time. It is characterized in that it is provided closer to the light incident side than the part. By inputting a trigger signal to the shutter unit that controls the transmission of light to the photometry unit, the light emission timing and the photometry timing can be synchronized.

  In addition, when the period in which the photometric unit performs measurement is CT, the measurement time in which the photometric unit performs measurement is MT, and the time in which the illumination light source emits light is ET, the time ET is expressed as “MT ≦ ET <MT + CT”. It is characterized by that. Thereby, the light emission time ET can be shortened and the heat damage with respect to an illumination light source can be suppressed.

  Further, the time ET is set to “ET = MT”. By matching the light emission time ET with the photometry time MT, the light emission time ET can be minimized. As a result, heat damage to the illumination light source can be minimized.

The optical measurement method of the present invention performs optical measurement of the illumination light source by receiving light emitted from the light emitting unit provided with the illumination light source by supplying a driving current to the illumination light source. when the measuring unit performs photometry, it is synchronized with the measurement timing of the photometry unit and the light emission timing of the light emitting portion by transmitting a trigger signal to and from the metering unit and the light emitting portion, in the photometric unit Control is based on the trigger signal so that the end of the measurement is delayed by a fixed time from the end of the supply of the drive current in the light emitting unit.

  In the present invention, the light emitting unit and the photometry unit are directly connected by the trigger signal transmission unit, and the trigger signal is transmitted between them. Thereby, the light emission timing and the photometry timing can be synchronized, and an accurate optical measurement can be performed while suppressing the influence of the fluctuation of the spectral characteristics. Moreover, since the light emission time can be shortened, damage caused by heat acting on the illumination light source can be reduced.

It is a block diagram which shows the structure of the measurement system in embodiment. 2 is a timing chart showing the operation of the configuration of FIG. 1. It is a block diagram which shows the structure of the measurement system in the modification 1. It is a block diagram which shows the structure of the measurement system in the modification 2. 5 is a timing chart showing the operation of the configuration of FIG. It is a block diagram which shows the structure of the measurement system in the modification 3. It is a block diagram which shows the structure of the measurement system in the modification 4. It is a timing chart which shows the operation | movement of the structure of FIG. It is a block diagram which shows the structure of the measurement system in the modification 5. It is a block diagram which shows the structure of the conventional measurement system. It is a timing chart which shows operation | movement of the structure of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following, a case where an LED is applied to the illumination light source and optical measurement of the LED is shown is shown, but an illumination light source other than the LED may be applied. Moreover, although the light from the LED is spectrally measured, the measurement (optical measurement of light having a single wavelength) may be performed without performing the spectroscopy.

  FIG. 1 shows a measurement system 1 for optically measuring LEDs. The measurement system 1 includes a light emitting unit 2, an integrating sphere 3, an optical fiber 4, a photometric unit 5, and a computer 6. The light emitting unit 2 and the photometric unit 5 are connected by a trigger signal transmission unit 20. The light emitting unit 2 includes a power source unit 7, an LED 8, a current path 9, and a current detection unit 10, and is a side that emits light L from the LED 8.

  The power supply unit 7 outputs a drive current for driving the LED 8 to the current path 9. The value of the drive current of the power supply unit 7 is set by the computer 6. Note that a current value may be set in the power supply unit 7 in advance without using the computer 6. The LED 8 is an illumination light source that emits light based on a drive current supplied from the power supply unit 7. The emitted light L is incident on the integrating sphere 3. A current detection unit 10 is provided in the current path 9 between the power supply unit 7 and the LED 8. The current detection unit 10 detects a drive current flowing in the current path 9 and outputs a trigger signal trig indicating that when a drive current is detected.

  The current detector 10 can use any means for detecting current. As the current detection unit 10, a current may be detected by forming a coil in a part of the current path 9 and detecting an electromotive force generated by the coil. Alternatively, a current may be detected by providing a resistor in the current path 9 and detecting the potential at both ends of the resistor. In short, any means for detecting the current flowing in the current path 9 can be applied.

  The integrating sphere 3 receives the light L emitted from the LED 8 and guides it to the optical fiber 4. Then, the light L guided by the optical fiber 4 is input to the photometry unit 5. The integrating sphere 3 and the optical fiber 4 may be omitted from the measurement system 1. However, since the light L can be guided from the light emitting unit 2 to the photometric unit 5 without loss, it is desirable to provide the integrating sphere 3 and the optical fiber 4.

  The photometry unit 5 measures the light L (photometry). For example, a spectrometer can be used as the measurement unit 5. The photometry unit 5 includes an optical unit 11, an AD conversion unit 12, a signal processing unit 13, and a timing control unit 14, and is a side for measuring the light L. The optical unit 11 optically detects the light L and includes a spectroscopic unit 15 and a detection unit 16. The spectroscopic unit 15 splits the light L guided through the optical fiber 4 into different wavelengths. For this purpose, a diffraction grating or the like can be used as the spectroscopic unit 15.

  The light L split by the spectroscopic unit 15 enters the detection unit 16. The detection unit 16 is an optical sensor, and photoelectrically converts the incident light L into an electrical signal. This electrical signal is output to the AD conversion unit 12 (optical unit output). The electric signal output from the detection unit 16 is an analog signal, and the AD conversion unit 12 converts the analog signal into a digital signal.

  The electric signal converted into a digital signal by the AD conversion unit 12 is input to the signal processing unit 13. The signal processing unit 13 performs correction (primary correction) such as offset, gain, and sensitivity on the electric signal. By performing this correction calculation, spectrum data indicating the spectrum of the light L is generated. This spectrum data is transferred to the computer 6.

  The timing control unit 14 is connected to the current detection unit 10 of the light emitting unit 2 via the trigger signal transmission unit 20 and receives a trigger signal trig from the current detection unit 10. Then, the timing control unit 14 performs timing control on the optical unit 11, the AD conversion unit 12, and the signal processing unit 13 based on the timing of the trigger signal trig.

  The computer 6 receives the spectral data transferred by the signal processing unit 13 and obtains values such as tristimulus values, chromaticity coordinates, luminous flux, radiant flux, dominant wavelength, peak wavelength, full width at half maximum based on the spectral data. Various operations are performed. By performing these calculations, the optical characteristics of the LED 8 are measured.

  Therefore, the computer 6 performs predetermined arithmetic processing on the spectrum data transferred from the signal processing unit 13 and sets a value of the drive current for the power supply unit 7. The computer 6 performs arithmetic processing or setting of drive current under the control of software operating on the CPU, and does not perform special timing control on the light emitting unit 2 and the photometric unit 5.

  The light emitting unit 2 and the photometry unit 5 are directly connected by a trigger signal transmission unit 20. The trigger signal transmission unit 20 only needs to be capable of transmitting a 1-bit trigger signal trig through a cable or the like.

  Next, the operation will be described. FIG. 2 shows the timing of the configuration of FIG. First, the computer 6 sets a drive current value for the power supply unit 7 in advance. And based on the set value, the power supply part 7 outputs a drive current. As a result, a drive current flows through the current path 9.

  The current detection unit 10 detects that a drive current has flowed through the current path 9. For example, the electromotive force of the coil or the potential difference between both ends of the resistor is detected to detect that the drive current has flowed. By detecting the drive current, the current detection unit 10 generates a trigger signal trig. Further, when the drive current flows through the current path 9, the drive current is supplied to the LED 8, and the LED 8 emits light.

  The timing at which the drive current is supplied to the LED 8 is the same as the timing at which the current detector 10 detects the drive current, that is, the timing at which the trigger signal trig is generated. However, it takes a short time from when the drive current is supplied to the LED 8 until the LED 8 actually emits light, and the LED 8 emits light slightly after the drive current flows (LED output).

  The power supply unit 7 outputs a drive current for a certain time. Therefore, the LED 8 stops emitting light when the drive current is not supplied. At this time, the time during which the LED 8 emits light is defined as the light emission time ET. The light L emitted from the LED 8 is incident on the photometry unit 5 via the integrating sphere 3 and the optical fiber 4 and is split by the spectroscopic unit 15. Then, the separated light L is detected by the detection unit 16.

  Before the light L is detected by the detection unit 16, the trigger signal trig generated by the current detection unit 10 is input to the timing control unit 14 of the photometry unit 5. The timing control unit 14 performs control so that photometry (measurement of the light L) is started after the elapse of a certain delay time LT from when the trigger signal trig is input.

  A certain time (delay time LT) is required until the light L emitted from the LED 8 is received by the detection unit 16. Therefore, the timing control unit 14 controls the detection unit 16 to start receiving the light L after the delay time LT has elapsed since the trigger signal trig was input. For example, when the photometry unit 5 is provided with shutter means such as an electronic shutter, the electronic shutter is changed from the closed state to the open state after a delay time LT has elapsed since the trigger signal trig was input. As a result, the light L is input to the optical unit 11.

  Therefore, the light L emitted from the LED 8 is input to the detection unit 16 of the optical unit 11. Thereby, photometry is started. Photometry is performed based on the light L received by the detector 16 during a fixed time (photometry time MT). Therefore, the light L is received by the detector 16 during the photometric time MT. For this purpose, the electronic shutter is opened and then closed after the photometric time MT has elapsed. Thereby, photometry is completed.

  The photometry of the photometry unit 5 is repeated at regular intervals (photometry cycle CT). Therefore, the photometric time MT is generated again after the photometric period CT from the end of the photometric time MT. By repeating this photometry, optical measurement of the LED 8 is performed. The number of repetitions can be arbitrarily set.

  The timing control unit 14 performs control so that the detection unit 16 outputs an electrical signal at the timing when the photometric time MT ends (reading start). As a result, an electrical signal is input to the AD conversion unit 12 (optical unit output). The AD converter 12 converts the analog signal into a digital signal. The converted digital signal is output to the signal processing unit 13 and correction calculation is performed.

  Thereby, spectrum data is generated, and the generated spectrum data is transferred to the computer 6 (communication). Then, the computer 6 performs various calculations such as the above-described tristimulus values based on the spectrum data. Thereby, the optical measurement of LED8 is performed.

  When the current detection unit 10 detects that the drive current has flowed through the current path 9, the current detection unit 10 generates a trigger signal trig and outputs the trigger signal to the photometry unit 5 via the trigger signal transmission unit 20. The LED 8 emits light when a drive current flows through the current path 9. That is, the trigger signal trig indicates the light emission timing of the LED 8.

  This trigger signal trig is input to the timing control unit 14 of the photometry unit 5. And the measurement time MT of the detection part 16 is controlled based on the trigger signal trig. That is, using the trigger signal trig, the photometry timing at which the photometry unit 5 performs measurement and the light emission timing of the light emitting unit 2 are synchronized.

  Thereby, the photometry part 5 can perform photometry with the timing synchronized with the timing which LED8 light-emitted. For this reason, photometry can always be performed at a fixed timing after the LED 8 emits light. Thereby, even if the spectral characteristics fluctuate due to the temperature rise that occurs after the LED 8 starts to emit light, the amount of fluctuation is always constant. For this reason, the accuracy of the optical measurement of the LED 8 can be ensured. That is, repeated photometry can be performed with a certain reproducibility.

  Further, since the light emission timing is synchronized with the photometry timing, the light emission time ET can be shortened. In the prior art, the light L is received at all times between the photometric times MT by making the light emission time ET longer than the time obtained by adding the photometric period CT and the photometric time MT (ET> CT + MT).

  In this embodiment, since the light emission timing and the photometry timing are synchronized using the trigger signal trig, it is not necessary to excessively increase the light emission time ET. By setting the light emission time ET to be equal to or longer than the light emission time ET, the light L can be received at all times during the photometric time MT. This enables accurate optical measurement.

  In FIG. 2, the light emission time ET is a time slightly longer than the time obtained by adding the photometry time MT and the delay time LT. Thereby, all the light L emitted from the LED 8 can be completely measured, and the light emission time ET can be set to a short time. By setting the light emission time ET to a short time, the amount of heat generated by the LED 8 can be suppressed. Thereby, the thermal stress with respect to LED8 can be suppressed.

  Further, the light emission time ET and the photometry time MT may be matched. That is, if the photometry is started after the delay time LT from the timing when the light emission is started and the photometry is finished after the delay time LT from the timing when the light emission is finished, the light L emitted from the LED 8 is changed. All can receive light completely. Thereby, the light emission time ET can be made the shortest time, and the heat damage to the LED 8 can be minimized.

  Accordingly, the light emission time ET is the shortest as the photometry time MT. Further, since the light emission timing and the photometry timing are synchronized, the light emission time ET can be made shorter than the time obtained by adding the photometry period CT and the photometry time MT (= CT + MT). Therefore, the light emission time ET can be set as “MT ≦ ET <CT + MT”. When the light emission time ET is the shortest, it is set as “ET = MT”. In practice, “ET> MT” is set in order to allow a slight timing shift.

  Further, as described above, by providing the delay time LT, the time lag from when the driving current is output until the detection unit 16 receives the light L is corrected. Since this time lag is delayed as the delay time LT, more accurate timing synchronization can be performed.

  In the configuration of FIG. 1, the signal processing unit 13 transfers spectral data to the computer 6, but optical measurement is performed by calculating values such as tristimulus values in the photometric unit 5. Also good. In this case, the computer 6 simply sets the drive current of the power supply unit 7, and this drive current can also be set in advance, so that the computer 6 can be omitted.

  Next, Modification 1 will be described. FIG. 3 shows a configuration of the first modification, in which the current detection unit 10 having the configuration of the embodiment of FIG. 1 is not provided, but a trigger output unit 21 is newly provided in the power supply unit 7. The trigger output unit 21 is a part for outputting a trigger signal trig. The trigger output unit 21 detects that the power supply unit 7 has output a drive current to the current path 9 (that the power supply unit 7 has been driven), and outputs the trigger signal trig. To do.

  Accordingly, the trigger signal trig is output from the trigger output unit 21 to the power supply unit 7 at the same time as the drive current is output. Also in the first modification, the light emission timing and the photometry timing are synchronized by the trigger signal trig as in the above-described embodiment. Therefore, the optical measurement of the LED 8 can be accurately performed, and heat damage to the LED 8 can be reduced.

  The timing at which the power supply unit 7 outputs the drive current (drive timing) can be arbitrarily set, but when the computer 6 sets the drive current value in the power supply unit 7, the power supply unit 7 outputs the drive current. Can start. Accordingly, the trigger output unit 21 detects that the value of the drive current has been set, and outputs the trigger signal trig.

  In Modification 1, it is necessary to newly provide a trigger output unit 21 in the power supply unit 7. For this purpose, it is necessary to prepare a new power supply unit 7 equipped with the trigger output unit 21 or to add a new circuit of the trigger output unit 21 to the power supply unit 7 already used. In this regard, in the above-described embodiment, the power supply unit 7 is not changed. That is, it is not necessary to prepare a new power supply unit 7, and it is not necessary to add a new circuit to the power supply unit 7.

  That is, in the above-described embodiment, the current detection unit 10 is simply provided in the current path 9. The current detection unit 10 only needs to add simple components such as a coil and a resistor. Therefore, the power supply unit 7 that has been used can be used as it is by adding an extremely simple configuration. Moreover, the power supply part 7 used for the other use can be diverted. And since a light emission timing and a photometry timing can be synchronized, an exact optical measurement can be performed and the heat damage with respect to LED8 can be reduced.

  Next, Modification 2 will be described. FIG. 4 shows a measurement system 1 of the second modification. The measurement system 1 has a plurality of photometry units. Here, there are three photometric units, a first photometric unit 31, a second photometric unit 32, and a third photometric unit 33. Of course, the number of photometry units may be two, or four or more. The configurations of the first photometry unit 31, the second photometry unit 32, and the third photometry unit 33 are the same as those of the photometry unit 5 shown in FIG.

  The integrating sphere 3 is connected to three optical fibers 34, 35, and 36, and guides the light L emitted from the LED 8 to the first photometry unit 31, the second photometry unit 32, and the third photometry unit 33. ing. The first photometry unit 31, the second photometry unit 32, and the third photometry unit 33 each split the incident light L and detect spectra having different wavelengths. Thereby, spectrum data of a wide range of wavelengths can be measured.

  At this time, the first photometry unit 31, the second photometry unit 32, and the third photometry unit 33 must measure the light L emitted at the same timing. This is because if the light L at different timings is measured, the optical measurement becomes inaccurate. Therefore, the light L emitted from the LED 8 at a certain timing is controlled so that all the photometric units (the first photometric unit 31, the second photometric unit 32, and the third photometric unit 33) measure the light.

  For this purpose, the trigger signal trig output from the current detection unit 10 is input to all photometry units. Thereby, the photometry timing of all the photometry parts can be synchronized with the light emission timing of the light emission part 2. FIG. For this reason, all the photometry units can perform photometry at the same timing, and the timing is synchronized with the light emission timing. Thereby, spectrum data of a wide range of wavelengths can be measured, accurate optical measurement can be performed, and thermal damage to the LED 8 can be suppressed.

  FIG. 5 shows the timing of the measurement system 1 of FIG. 4, and the photometry timings of the first photometry unit 31, the second photometry unit 32, and the third photometry unit 33 can be set to the same timing. And the timing is synchronizing with the light emission timing of LED8. Thereby, the said effect is acquired because the photometry timing and light emission timing of all the photometry parts synchronize.

  In the configuration of FIG. 4, the current detection unit 10 outputs the trigger signal trig, but the trigger signal trig may be output from the trigger output unit 21 provided in the power supply unit 7 as in the first modification. Good.

  Next, Modification 3 will be described. The measurement system 1 of the third modification shown in FIG. 6 does not include the current detection unit 10 of the embodiment of FIG. 1, but a trigger output unit 37 is newly added to the photometry unit 5 and a trigger is newly added to the power supply unit 7 An input unit 38 is added. The trigger output unit 37 outputs the trigger signal trig to the trigger input unit 38 via the trigger signal transmission unit 20.

  In the embodiment described above, a trigger signal is output from the light emitting unit 2 to the photometric unit 5, but a trigger output unit 37 may be provided in the photometric unit 5 as in the third modification. The trigger output unit 37 outputs the trigger signal trig, so that the light emission timing of the light emitting unit 2 can be synchronized with the photometric timing of the photometric unit 5. Also in this case, accurate optical measurement can be performed, and thermal damage to the LED 8 can be reduced.

  Next, Modification 4 will be described. FIG. 7 shows a measurement system 1 according to the fourth modification, and an acousto-optic switch (AO switch in the drawing) 40 is newly provided in the configuration of the third modification in FIG. The acousto-optic switch 40 is an optical switch that controls on (transmission) and off (interruption) of the light L guided through the optical fiber 4. As a result, the light L becomes a light pulse with a constant period.

  The acousto-optic switch 40 receives the trigger signal trig output from the trigger output unit 37 and performs an on / off operation at a timing synchronized with the trigger signal trig. FIG. 8 shows the timing. As shown in this figure, control is performed so that the light L is transmitted for the photometric time MT after the elapse of the delay time LT after the trigger signal trig is input. Further, control is performed so that the light L is not transmitted during the time other than the photometry time MT.

  Thereby, the light L is transmitted only during the photometric time MT, and the light L is detected by the detector 16. As a result, the light L is detected by the detector 16 for the photometric time MT. That is, exposure for the photometric time MT is performed. As a result, the light L can be accurately measured.

  When the photometry unit 5 has shutter means such as an electronic shutter, the shutter means is controlled so that it is opened for the photometric time MT, and other times are closed. , Photometry can be performed. At this time, the photometry unit 5 may not be provided with shutter means, or may be omitted actively.

  For this purpose, the acousto-optic switch 40 is arranged on the incident side of the light L with respect to the photometry unit 5. The trigger signal trig is input to the acousto-optic switch 40 so that the photometric timing is synchronized with the light emission timing. The acousto-optic switch 40 has the same function as the electronic shutter, and an electronic shutter may be provided instead of the acousto-optic switch 40.

  That is, even when the shutter means (the means for performing control to transmit or block the light L) such as the acousto-optic switch 40 and the electronic shutter is configured to be independent from the photometry unit 5, the photometry timing and the light emission timing are synchronized. Can do. Thereby, an accurate optical measurement can be performed and thermal damage can be reduced.

  Next, Modification 5 will be described. FIG. 9 shows a measurement system 1 according to the fifth modification, and the acousto-optic switch 40 described in the fourth modification is added to the embodiment of FIG. The trigger signal trig output from the current detection unit 10 is input to the acousto-optic switch 40. Thereby, the on / off operation of the acousto-optic switch 40 can be synchronized with the trigger signal trig.

  The acousto-optic switch 40 defines the photometry timing of the photometry unit 5, and the light emission timing of the light emitting unit 2 and the photometry timing of the photometry unit 5 can be synchronized by synchronizing this with the trigger signal trig. In the fourth modification, the acoustooptic switch 40 and the light emitting unit 2 are synchronized with the trigger signal trig output from the photometry unit 5, but as in the fifth modification, the acoustooptic switch 40 and the trigger signal trig output from the light emitting unit 2 are synchronized. The photometry unit 5 can also be synchronized. Also by this, an accurate optical measurement can be performed and thermal damage can be reduced.

DESCRIPTION OF SYMBOLS 1 Measurement system 2 Light emission part 5 Photometry part 6 Computer 7 Power supply part 8 LED
DESCRIPTION OF SYMBOLS 9 Current path 10 Current detection part 11 Optical part 14 Timing control part 15 Spectroscopic part 16 Detection part 20 Trigger signal transmission part 21 Trigger output part 40 Acousto-optic switch

Claims (8)

A light emitting unit that emits light from the illumination light source by supplying a driving current to the illumination light source;
A photometric unit that receives light emitted from the illumination light source and performs optical measurement of the illumination light source; and
A trigger signal transmission unit that connects between the light emitting unit and the photometric unit, and transmits a trigger signal for synchronizing the light emission timing of the light emitting unit and the measurement timing of the photometric unit;
Wherein as measured at the end of measurement in the light unit is delayed by a predetermined time than the time the supply end of the driving current in the light-emitting unit, a timing controller for controlling, based on the trigger signal,
An optical measuring device comprising: The light emitting unit includes a current detection unit that transmits the trigger signal to the photometry unit when it is detected that the drive current has flowed through a current path connecting the power source unit and the illumination light source. The optical measuring device according to claim 1, wherein 2. The optical device according to claim 1, wherein the power supply unit includes a trigger output unit that outputs the trigger signal to the photometry unit when output of the drive current to the illumination light source is started. measuring device. A plurality of the photometric units that measure the dispersed light by separating the light emitted from the illumination light source into different wavelengths,
4. The trigger signal is output to all the photometry units to synchronize the light emission timings of the light emitting units and the measurement timings of all the photometry units. The optical measuring device according to item. Shutter means for controlling the light emitted from the light emitting part to enter the light measuring part only during the time when the light measuring part performs measurement and to prevent the light from entering the light measuring part at times other than the measurement time from the light measuring part. The optical measuring device according to any one of claims 1 to 3, wherein the optical measuring device is provided on an incident side of the light. Suppose that the period when the photometry unit performs measurement is CT, the measurement time when the photometry unit performs measurement is MT, and the time when the illumination light source emits light is ET, this time ET is “MT ≦ ET <MT + CT”. The optical measuring device according to claim 1, wherein the optical measuring device is a light emitting device. The optical measurement apparatus according to claim 6, wherein the time ET is “ET = MT”. When the light meter that performs optical measurement of the illumination light source by receiving light emitted from the light emitting unit provided with the illumination light source by supplying a driving current to the illumination light source,
Synchronizing the light emission timing of the light emitting unit and the measurement timing of the photometric unit by transmitting a trigger signal between the light emitting unit and the photometric unit,
Optical measuring method characterized in that at the end of measurement in the measuring light portion so as to delay by a predetermined time than the time the supply end of the driving current in the light-emitting portion is controlled on the basis of the trigger signal .

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