JP2014115215A - Device and method for measuring light distribution characteristics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light distribution characteristic measurement device and a light distribution characteristic measurement method which allow for measuring light distribution characteristics of a light source with higher accuracy.SOLUTION: A light distribution characteristic measurement device 100 includes: a first rotating mechanism for rotating a light source 2 about a first axis; a detection unit 40 provided on a second axis perpendicular to the first axis; an arm 22 for guiding light from the light source to the detection unit; and a second rotating mechanism for rotating the arm about the second axis. The arm includes: a first light path conversion unit 30 which is located on a virtual plane that is orthogonal to the second axis and passes the center of the light source to convert a path of the light from the light source; a light guide path which guides the light whose path was converted by the first light path conversion unit; and a second light path conversion unit which is located on the second axis to output the light entering through the light guide path to a direction parallel to the second axis.

Description

  The present invention relates to a light distribution characteristic measuring apparatus and a light distribution characteristic measuring method for measuring a light distribution characteristic of a light source.

  A light distribution characteristic is known as one of the characteristics of light emitted from a light source. The light distribution characteristic means a spatial distribution of luminous intensity (or luminance) by a light source. As the light distribution characteristics, both absolute value light distribution and relative value light distribution are used. The absolute value light distribution is obtained by measuring the spatial distribution of the absolute value of luminous intensity, and is used for obtaining the total luminous flux generated by the light source. On the other hand, the relative value light distribution is obtained by measuring a spatial distribution of relative values of luminous intensity, and is used for obtaining a light distribution pattern. Generally, it is not easy to measure the light distribution characteristics of a light source having a complicated light distribution pattern or a light source whose characteristics are unknown. The following prior arts are known for such a light distribution characteristic measuring method and measuring apparatus.

  As one form of such a light distribution characteristic measuring apparatus, Japanese Patent Laid-Open No. 58-117422 (Patent Document 1), Japanese Patent Laid-Open No. 60-187825 (Patent Document 2), and Japanese Patent Laid-Open No. 2000-258246 ( Patent Document 3) discloses a configuration in which a plurality of light receiving elements are arranged around a light source. Further, Japanese Patent Application Laid-Open No. 57-090121 (Patent Document 4) discloses a configuration in which a light-receiving unit composed of a plurality of light-receiving elements is rotatable around a light source.

  As another embodiment of the light distribution characteristic measuring device, Japanese Patent Laid-Open No. 62-250325 (Patent Document 5), Japanese Patent Laid-Open No. 07-294328 (Patent Document 6), and Japanese Patent Laid-Open No. 2003-247888 (Patent Document 7). Discloses a configuration in which a mirror is disposed in an optical path between a light source and a light receiving unit, and measurement is performed by sequentially changing the relative position of the mirror with respect to the light source.

  As another form of the light distribution characteristic measuring apparatus, Japanese Patent Laid-Open No. 09-264781 (Patent Document 8) discloses a configuration for performing measurement while rotating and moving a light source.

JP 58-117422 A JP-A-60-187825 JP 2000-258246 A JP-A-57-090121 JP 62-250325 A Japanese Patent Application Laid-Open No. 07-294328 Japanese Patent Laid-Open No. 2003-247888 Japanese Patent Laid-Open No. 09-264781

JIS C 8105-5: 2011 "Lighting fixtures-Part 5: Light distribution measurement method"

The configuration disclosed in the prior art documents as described above has the following problems.
First, configurations as disclosed in Japanese Patent Application Laid-Open No. 58-117422 (Patent Document 1), Japanese Patent Application Laid-Open No. 60-187825 (Patent Document 2), and Japanese Patent Application Laid-Open No. 2000-258246 (Patent Document 3). However, there is a problem that a plurality of light receiving elements are required and the apparatus is increased in size. In addition, there is a problem that the spectroscopic measurement as the light distribution characteristic measurement is difficult.

  Next, the configuration disclosed in Japanese Patent Laid-Open No. 57-090121 (Patent Document 4) has a problem that the measurement accuracy is lowered. Specifically, when performing spectroscopic measurement as a light distribution characteristic measurement, it is necessary to employ a spectroscopic measurement device including optical components such as slits, diffraction gratings, and light receiving elements, but by moving the spectroscopic measurement device, It affects the alignment of the optical components inside. As a result, the accuracy of wavelength setting and spectral response decreases. Therefore, from the viewpoint of measurement accuracy, it is difficult to adopt a configuration in which the spectrometer is rotated around the light source.

  Even in the configurations disclosed in Japanese Patent Application Laid-Open No. Sho 62-250325 (Patent Document 5) and Japanese Patent Application Laid-Open Publication No. 2003-247888 (Patent Document 7), the light receiving unit rotates, so that there is a problem from the viewpoint of measurement accuracy. . In addition, the configuration disclosed in Japanese Patent Application Laid-Open No. 07-294328 (Patent Document 6) has a problem that spectroscopic measurement is difficult.

  Further, in JIS C 8105-5: 2011 “Lighting fixtures—Part 5: Light distribution measurement method” (Non-patent Document 1) established in 2011, “the lighting fixture is rotated or turned on during light distribution measurement”. The light distribution measuring device that changes the light intensity can be used only for lighting fixtures in which the rotation of the lighting fixture or the change in lighting posture does not substantially affect the light distribution characteristics. Therefore, it is necessary to measure the light distribution characteristic while maintaining the lighting posture of the light source for the light source whose lighting posture may affect the light distribution characteristic. From this point of view, the configuration disclosed in Japanese Patent Application Laid-Open No. 09-264781 (Patent Document 8) cannot be applied to all light sources.

  An object of the present invention is to provide a light distribution characteristic measuring apparatus and a light distribution characteristic measuring method capable of measuring the light distribution characteristic of a light source with higher accuracy.

  According to an aspect of the present invention, a light distribution characteristic measuring apparatus for measuring a light distribution characteristic of a light source is provided. The light distribution characteristic measurement device includes a first rotation mechanism for rotating the light source along the first axis, a detection unit provided on a second axis orthogonal to the first axis, An arm for guiding the light to the detection unit and a second rotation mechanism for rotating the arm along the second axis are included. The arm is provided on a virtual plane orthogonal to the second axis and passing through the center of the light source. The first optical path conversion unit converts the optical path of light from the light source, and the optical path is converted by the first optical path conversion unit. A light guide path that guides the emitted light, and a second optical path conversion section that is provided on the axis of the second axis and that emits light incident through the light guide path in a direction parallel to the second axis.

  Preferably, the arm further includes a light absorption unit that is provided on the opposite side of the light source from the first optical path conversion unit and absorbs light emitted from the light source to the opposite side of the first optical path conversion unit. .

  Preferably, the orientation characteristic measuring apparatus is a third rotation mechanism for rotating the light source along a third axis that is parallel to the second axis and is further from the second optical path changing unit. Further included.

  Preferably, the second optical path conversion unit includes an integrating sphere connected to the light guide path and provided with an extraction window on the axis of the second axis.

Preferably, the second optical path changing unit includes a mirror provided on the axis of the second axis.
Preferably, the detection unit includes a spectroscopic measurement device.

  According to another aspect of the present invention, a light distribution characteristic measuring method for measuring the light distribution characteristic of a light source is provided. The light distribution characteristic measuring method includes a step of arranging a light source at a predetermined angle along a first axis, and guiding light from the light source to a detection unit provided on a second axis orthogonal to the first axis. And rotating the arm along a second axis orthogonal to the first axis, and measuring the light from the light source by the detection unit. The arm is provided on a virtual plane orthogonal to the second axis and passing through the center of the light source. The first optical path conversion unit converts the optical path of light from the light source, and the optical path is converted by the first optical path conversion unit. A light guide path that guides the emitted light, and a second optical path conversion section that is provided on the axis of the second axis and that emits light incident through the light guide path in a direction parallel to the second axis.

  According to the present invention, the light distribution characteristics of the light source can be measured with higher accuracy.

It is a perspective view which shows the whole structure of the measuring apparatus according to Embodiment 1. FIG. It is a schematic diagram which shows the cross-sectional structure of the measuring apparatus according to Embodiment 1. It is sectional drawing which shows the more detailed structure of the horizontal rotation stage shown in FIG. It is a schematic diagram which shows the electrical structure of the measuring apparatus according to Embodiment 1. 3 is a schematic diagram showing a hardware configuration of a processing apparatus according to the first embodiment. FIG. 6 is a schematic diagram showing a cross-sectional configuration of a measuring apparatus according to a modification of the first embodiment. FIG. FIG. 6 is a schematic diagram showing a cross-sectional configuration of a measuring apparatus according to a second embodiment. FIG. 6 is a schematic diagram showing a cross-sectional configuration of a measuring apparatus according to a third embodiment. It is a schematic diagram which shows the time change of the rotation angle at the time of measuring a light distribution characteristic using the measuring apparatus according to this Embodiment. It is a figure for demonstrating the process sequence at the time of measuring a light distribution characteristic using the measuring apparatus according to this Embodiment. It is a flowchart which shows the process sequence at the time of measuring a light distribution characteristic using the measuring apparatus according to this Embodiment.

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

  The light distribution characteristic measuring device (hereinafter also simply referred to as “measuring device”) according to the present embodiment has a plurality of light sources in a predetermined spatial coordinate system centered on a light source to be measured (hereinafter also simply referred to as “light source”). The light distribution characteristics are obtained by measuring the light intensity (or spectrophotometer) at the position of. That is, the measuring apparatus according to the present embodiment measures the light distribution characteristics of the light source. The type of the light source is not limited and can be applied to various light sources such as incandescent bulbs, fluorescent lamps, LEDs (Light Emitting Device), and organic EL (Electro Luminescence). Note that the light source to be measured may be referred to as a sample light source.

[Embodiment 1]
<1. Device configuration>
First, the apparatus configuration of measuring apparatus 100 according to the first embodiment will be described. FIG. 1 is a perspective view showing an overall configuration of measuring apparatus 100 according to the first embodiment. FIG. 2 is a schematic diagram showing a cross-sectional configuration of measuring apparatus 100 according to the first embodiment.

  Referring to FIGS. 1 and 2, in measurement apparatus 100, light source 2 is rotatably disposed along first rotation axis AX1, and along second rotation axis AX2 orthogonal to first rotation axis AX1. The arm 22 is rotatably arranged. The detector 40 emits light from the light source 2 at each measurement position as the combination of the rotation angle θ along the first rotation axis AX1 and the rotation angle φ along the second rotation axis AX2 is sequentially changed. The optical characteristics of the emitted light are sequentially detected. As described above, the measurement apparatus 100 measures the light distribution of the light source 2 by sequentially changing the positional relationship of the measurement position with respect to the light source 2.

  Specifically, the measuring apparatus 100 includes a base portion 4 and first and second support columns 10 and 20 provided on the base portion 4.

  The first support column 10 is provided with a rotation mechanism for rotating the light source 2 along the first rotation axis AX1. More specifically, the first support column 10 is provided with a horizontal rotation stage 12 to which the light source 2 is attached at the tip thereof, and a housing 14 that holds the horizontal rotation stage 12. The horizontal rotation stage 12 includes a lighting jig (not shown) and the like, and supplies power for lighting the light source 2. The horizontal rotation stage 12 includes a drive unit such as a pulse motor that can control angular displacement with high accuracy.

  The second support column 20 is provided with a rotation mechanism for rotating the arm 22 along the second rotation axis AX2. More specifically, the second support column 20 is provided with a vertical rotation stage 28 that rotatably supports the arm 22 and a detection unit 40. The detection unit 40 is provided on the second rotation axis AX <b> 2 on the opposite side of the vertical rotation stage 28 from the arm 22. The arm 22 guides the light from the light source 2 to the detection unit 40 regardless of the rotation angle φ.

  An incident optical system 38 is provided inside the vertical rotation stage 28, and maintains a state of optical communication with the opposite surface of the arm 22 without depending on the rotation angle φ of the arm 22. The vertical rotation stage 28 includes a drive unit such as a pulse motor that can control angular displacement with high accuracy.

  The arm 22 has a substantially L-shape, and includes an optical path conversion unit 30 that converts the optical path of light from the light source 2 at the tip thereof. The optical path conversion unit 30 functions as a light receiving unit that receives light from the light source 2. As an example, the optical path conversion unit 30 includes a mirror 31 that converts the optical path of incident light by 90 °. The present invention is not limited to the 90 ° optical path changing mirror 31 and may be realized by using various optical components such as a prism. From the viewpoint of reducing the measurement error, it is preferable to limit the field of view 32 of the mirror 31 to a range including the light source 2.

  The optical path changing unit 30 is arranged so that the field of view 32 always includes the light source 2 without depending on the rotation angle φ of the arm 22. That is, the optical path changing unit 30 is orthogonal to the second rotation axis AX2 and includes a first rotation axis AX2 including the optical axis AXV and the first rotation axis AX1 shown in FIG. Plane). In the first embodiment, the optical path conversion unit 30 converts the optical path of light from the incident light source 2 in a direction parallel to the second rotation axis AX2.

  The arm 22 further includes an optical fiber 26 connected to the optical path changing unit 30 and an integrating sphere 24 connected to the optical fiber 26. The optical fiber 26 corresponds to a light guide that guides the light whose optical path has been converted by the optical path converter 30. The optical fiber 26 is fixed to the surface of the arm 22 by one or more fixing tools 27. The integrating sphere 24 corresponds to an optical path conversion unit that emits light incident through the optical fiber 26 that is a light guide path in a direction parallel to the second rotation axis AX2. That is, the optical path conversion unit includes an integrating sphere 24 that is connected to the optical fiber 26 that is a light guide path and that has an extraction window provided on the second rotation axis AX2.

  On the inner surface of the integrating sphere 24, a diffuse reflection layer 25 made of a diffuse reflector such as barium sulfate is formed. Therefore, the light incident on the integrating sphere 24 through the optical fiber 26 is integrated (averaged) in the integrating sphere 24, and the integrated light enters the detection unit 40 through the incident optical system 38.

  FIG. 3 is a cross-sectional view showing a more detailed configuration of the vertical rotation stage 28 shown in FIG. Referring to FIG. 3, vertical rotation stage 28 includes a horizontal rotation shaft 282 for rotating arm 22 and integrating sphere 24 along second rotation axis AX2, and a pulse motor for rotationally driving horizontal rotation shaft 282. 284. The incident optical system 38 passes through the center of the horizontal rotation shaft 282. The incident optical system 38 optically connects the integrating sphere 24 and the detection unit 40. A bearing 286 is provided between the incident optical system 38 and the inner surface of the horizontal rotation shaft 282 so that the incident optical system 38 is not affected by the rotation of the arm 22 and the integrating sphere 24. The incident optical system 38 may include a lens system for collecting incident light.

  Referring to FIGS. 1 and 2 again, the detection unit 40 detects the optical characteristics of the light input through the incident optical system 38. As the detection unit 40, a light receiving element for detecting the intensity of light such as a photodiode may be employed, or a spectroscopic measurement device for detecting the intensity (spectrum) for each wavelength may be employed. .

  The measurement result acquired by the detection unit 40 is output to the processing device 300. The processing device 300 sequentially stores the measurement results in association with the measurement position (typically a combination of the rotation angle θ and the rotation angle φ) in the measurement device 100. And the processing apparatus 300 calculates the light distribution characteristic of the light source 2 from the measurement result stored sequentially.

  A counterweight 34 is preferably provided at the end of the arm 22 opposite to the end where the optical path changing unit 30 is provided. This is to prevent the occurrence of excessive bias when the arm 22 is rotated by the vertical rotation stage 28.

<2. Electrical configuration>
Next, an electrical configuration of measuring apparatus 100 according to the first embodiment will be described.

  FIG. 4 is a schematic diagram showing an electrical configuration of measuring apparatus 100 according to the first embodiment. Referring to FIG. 4, measurement apparatus 100 includes a pulse motor 124 and a pulse motor controller 126 as a part of a rotation mechanism for rotating light source 2 along first rotation axis AX1. In addition, the measuring apparatus 100 includes a pulse motor 284 and a pulse motor controller 286 as part of a rotation mechanism for rotating the arm 22 along the second rotation axis AX2. The pulse motors 124 and 284 change the rotational position (phase) in proportion to the number of drive pulses from the pulse motor controllers 126 and 286, respectively.

  Measurement apparatus 100 further includes a pulse counter 350 that counts drive pulses output from pulse motor controllers 126 and 286. The pulse counter 350 integrates the number of drive pulses output from the pulse motor controllers 126 and 286, respectively, and when the integrated value satisfies the measurement condition set in advance by the processing device 300, the pulse counter 350 Output trigger to start measurement. As this measurement condition, for example, a condition in which the rotation angle of the arm 22 increases by 5 ° can be considered.

  The operation of the electrical configuration shown in FIG. 4 is as follows. First, in accordance with the drive command 1 and the drive command 2 output from the processing device 300, the pulse motor controllers 126 and 286 give drive pulses corresponding to the pulse motors 124 and 284, respectively. The pulse motor 124 rotates the light source 2 by an angle corresponding to the given drive pulse. Similarly, the pulse motor 284 rotates the arm 22 by an angle corresponding to a given drive pulse (or at a speed corresponding to the drive pulse). The pulse counter 350 counts the driving pulses of the pulse motor controllers 126 and 286 and monitors the rotation angles of the light source 2 and the arm 22. For example, the pulse counter 350 outputs a trigger instructing the start of measurement to the detection unit 40 every time the arm 22 moves by a predetermined angle (for example, 5 °). The detection unit 40 performs measurement over a preset exposure time in response to the input trigger signal, and ends the measurement when the set exposure time has elapsed. Then, the detection unit 40 outputs the measurement result to the processing device 300.

  Here, processing apparatus 300 according to the first embodiment will be described. FIG. 5 is a schematic diagram showing a hardware configuration of processing apparatus 300 according to the first embodiment. Referring to FIG. 5, processing device 300 is typically implemented by a computer. Specifically, the processing device 300 temporarily stores a CPU (Central Processing Unit) 302 that executes various programs including an operating system (OS) and data necessary for the execution of the program by the CPU 302. The memory 312 and a hard disk (HDD: Hard Disk Drive) 310 that stores a program executed by the CPU 302 in a nonvolatile manner are included. The hard disk 310 stores in advance a program for realizing processing as will be described later, and such a program is stored in a CD-ROM drive 314 by a CD-ROM (Compact Disk-Read Only Memory) 314a. Read from. Alternatively, a program received via a network from a server device or the like via a network interface (I / F) 306 may be stored in the hard disk 310.

  The CPU 302 receives a measurement result from the detection unit 40 via an I / O (Input Output) unit 316 and gives a drive command and measurement conditions to each element shown in FIG.

  The CPU 302 receives an instruction from a user or the like via an input unit 308 including a keyboard and a mouse, and outputs a light distribution characteristic calculated by executing the program to the display 304 and the like.

  Part or all of the functions mounted on the processing apparatus 300 may be realized by dedicated hardware.

<3. Advantage>
In measurement apparatus 100 according to the first embodiment, light source 2 is attached to horizontal rotation stage 12 of first support column 10 that is independent of measurement apparatus 100. An integrating sphere 24 is disposed at the rotation center of the vertical rotation stage 28, and an optical fiber 26 that optically connects the integrating sphere 24 to the tip of the arm 22 is disposed. The optical fiber 26 is fixed to the arm 22 by a fixture 27. A mirror 31 provided at the tip of the arm 22 faces the light source 2 in the field of view. The integrating sphere 24 guides the light from the light source 2 to the detection unit 40 via the incident optical system 38 that penetrates the vertical rotation stage 28.

  By adopting such a configuration, the integrating sphere 24 rotates together with the vertical rotation stage 28, but the extraction window of the integrating sphere 24 connected to the incident optical system 38 on the detection unit 40 side changes its position. I won't let you. In the configuration in which the optical fiber is fixed to the rotating arm, the rotation of the arm may cause twisting or stress in the rotation direction of the optical fiber, which may reduce the measurement accuracy. However, in the configuration according to the first embodiment, the arm Even if the 22 rotates, the optical fiber 26 is not twisted or stressed. Therefore, it is possible to prevent a decrease in measurement accuracy.

  In addition, since the lighting posture of the light source 2 is kept constant, it is possible to prevent a change in light characteristics during measurement due to a change in heat dissipation conditions.

  In the first embodiment, the first support column 10 provided with the horizontal rotation stage 12 for rotating the light source 2 and the second support column 20 provided with the vertical rotation stage 28 on which the detection unit 40 is disposed are independent of each other. ing. Therefore, the arms 22 of the vertical rotation stage 28 can be continuously rotated in one direction without interference between the two. Thus, continuous measurement can be performed without stopping the vertical rotation stage 28 every time the rotation angle corresponding to the measurement position is reached, and the measurement time can be shortened.

[Modification of Embodiment 1]
In the above-described first embodiment, the configuration in which the integrating sphere 24 is used as the optical path conversion unit that emits the light incident through the light guide path in a direction parallel to the second rotation axis AX2 is exemplified. May be used. As an example, an example using a 90 ° optical path conversion mirror will be described.

  FIG. 6 is a schematic diagram showing a cross-sectional configuration of measuring apparatus 100A according to the modification of the first embodiment. 6 is different from measurement apparatus 100 according to the first embodiment shown in FIG. 2 in that optical path changing unit 50 is employed instead of integrating sphere 24. Since other configurations are similar to those of measuring apparatus 100 according to the first embodiment, detailed description will not be repeated.

  The optical path conversion unit 50 converts the optical path of light incident through the optical fiber 26 that is a light guide path, and guides it to the detection unit 40 via the incident optical system 38 that penetrates the vertical rotation stage 28. More specifically, the optical path conversion unit 50 includes a mirror 52 for 90 ° optical path conversion. A mirror 52 is provided around the intersection of the optical axis on the exit side of the optical fiber 26 and the optical axis of the incident optical system 38. Thus, in this modification, the optical path changing unit 50 includes the mirror 52 provided on the second rotation axis AX2.

  Also in this modification, the same advantages as those of the first embodiment can be obtained. In addition, the structure can be further simplified as compared with the case where the integrating sphere 24 is employed.

[Embodiment 2]
Next, a configuration that can reduce the stray light component generated during measurement will be described. FIG. 7 is a schematic diagram showing a cross-sectional configuration of measuring apparatus 100B according to the second embodiment. Referring to FIG. 7, measurement device 100B according to the second embodiment has a light absorption unit 60 for absorbing light emitted from light source 2, as compared with measurement device 100 according to the first embodiment shown in FIG. Is further different. Since other configurations are similar to those of measuring apparatus 100 according to the first embodiment, detailed description will not be repeated.

  The light absorbing unit 60 and the support member 62 that supports the light absorbing unit 60 may be configured integrally with the arm 22 or may be configured to be detachable from the arm 22. When configured to be detachable from the arm 22, the light absorbing portion 60 and the support member 62 may be configured to be attachable instead of the counterweight 34 shown in FIGS. 2 and 6.

  The light absorption unit 60 mainly absorbs light emitted from the light source 2 to the side opposite to the optical path conversion unit 30. In other words, the light incident on the light absorber 60 is absorbed without being reflected inside. The light absorption unit 60 is preferably arranged so as to include a cross-sectional range at a position where the light absorption unit 60 exists in the field of view 32 of the optical path conversion unit 30. As a result, it is possible to reduce a phenomenon in which light emitted from the light source 2 in a direction different from the direction in which the optical path changing unit 30 exists is reflected at some part and is incident on the optical path changing unit 30. That is, the stray light component (error component) incident on the optical path changing unit 30 can be reduced.

  As described above, by providing the light absorbing unit 60 on the opposite side of the optical path changing unit 30 (the light receiving unit that receives light from the light source 2) with respect to the rotation axis of the vertical rotating stage 28, stray light that causes measurement errors. Components can be reduced.

  As the light absorption unit 60, any configuration can be adopted as long as it can absorb incident light. For example, it can be realized by using a cone-shaped light trap or the like. Thus, in measuring apparatus 100B according to the second embodiment, arm 22 is provided on the side opposite to optical path changing unit 30 with respect to light source 2, and the light emitted from light source 2 to the side opposite to optical path changing unit 30 is emitted. A light absorbing portion 60 for absorbing is included.

  According to the second embodiment, the same advantages as those of the first embodiment described above can be obtained, and the stray light component that causes a measurement error can be reduced, so that the measurement accuracy can be increased.

  By configuring the light absorption unit 60 and the support member 62 to be detachable from the arm 22, for example, the type of the light absorption unit 60 may be varied according to the type (light emission area) of the light source 2. . Furthermore, the light absorption unit 60 as described above may be provided for the modification of the first embodiment described above.

[Embodiment 3]
In the above-described first embodiment and its modified examples, and the second embodiment, the support column provided with the light source 2 and the support column provided with the optical path conversion unit 30 (light receiving unit) and the detection unit 40 are independent from each other. The configuration is illustrated. On the other hand, in Embodiment 3, it illustrates about the structure by which the light source 2, the optical path conversion part 30 (light-receiving part), and the detection part 40 are provided in the same support pillar.

  FIG. 8 is a schematic diagram showing a cross-sectional configuration of measuring apparatus 200 according to the third embodiment. Referring to FIG. 8, in measuring apparatus 200 according to the third embodiment, light source 2 is arranged to be rotatable along first rotation axis AX1 and third rotation axis AX3 orthogonal to first rotation axis AX1. Is arranged so as to be rotatable. More specifically, the light source 2 is disposed such that the light emission center substantially coincides with the intersection of the first rotation axis AX1 and the third rotation axis AX3. Here, the second rotation axis AX2 and the third rotation axis AX3 are parallel.

  By adopting the configuration as shown in FIG. 8, the distance L between the light path conversion unit 30 as the light receiving unit and the light source 2 can be kept constant. With this configuration, the lighting posture of the light source 2 can be maintained constant regardless of the rotation angle of the optical path conversion unit 30 that is a light receiving unit.

  Specifically, in the measuring apparatus 200, a second vertical rotation stage 70 is provided at the tip of the arm 22. Further, the arm 22 is provided with a horizontal rotary stage 80 to which the light source 2 is attached at the tip thereof via a second vertical rotary stage 70 and a support member 90 that supports the horizontal rotary stage 80. The support member 90 has a substantially L shape, and is disposed so as to be rotatable along the third rotation axis AX3 by the second vertical rotation stage 70. Further, the light source 2 is disposed so as to be rotatable along the first rotation axis AX1 by the horizontal rotation stage 80. The horizontal rotation stage 80 includes a lighting jig (not shown) and supplies a power source for lighting the light source 2.

  Since other configurations are similar to those of measuring apparatus 100 according to the first embodiment, detailed description will not be repeated.

  When the arm 22 rotates along the second rotation axis AX2, the support member 90 also rotates along the third rotation axis AX3. The rotation angle of the support member 90 is determined so as to cancel the change in the lighting posture of the light source 2 caused by the rotation of the arm 22. For example, for a light source that is assumed to be used in a suspended state, a lighting posture that always faces downward in gravity is maintained. As a result, it is possible to prevent changes in optical characteristics due to changes in heat dissipation conditions during measurement.

  The measuring apparatus 200 according to the third embodiment rotates the light source 2 along the third rotation axis AX3 that is parallel to the second rotation axis AX2 and is further away from the optical path conversion unit 30 that is the light receiving unit. The second vertical rotation stage 70 (rotation mechanism). As described above, in the measuring apparatus 200, the second vertical rotation stage 70 is provided at the tip portion opposite to the tip portion where the light receiving portion of the vertical rotation stage 28 is provided, and the light source 2 is provided on the second vertical rotation stage 70. A horizontal rotation stage 80 is provided for rotation. The processing apparatus 300 controls the second vertical rotation stage 70 so as to keep the lighting posture of the light source 2 constant in conjunction with the rotation of the vertical rotation stage 28.

  Further, in measuring apparatus 200 according to the third embodiment, the photometric distance from light source 2 to the light receiving unit can be approximately doubled as compared with measuring apparatus 100 according to the first embodiment. Therefore, the light distribution characteristic of a larger light source can be measured.

[Processing procedures related to measurement]
Next, a processing procedure when measuring the light distribution characteristics of the light source 2 using the measuring device according to each of the above-described embodiments will be described. The processing procedure described below can be applied to any of the measurement apparatuses described above.

  In the measurement apparatus described above, the combination of the rotation angle θ (rotation angle of the light source 2) along the first rotation axis AX1 and the rotation angle φ (rotation angle of the arm 22) along the second rotation axis AX2 is sequentially changed. Then, the optical characteristic of the light emitted from the light source 2 at each measurement position is detected.

  As a typical measurement procedure, the rotation angle of the light source 2 and the arm 22 is set to a value corresponding to each measurement position, and the measurement is performed while the light source 2 and the arm 22 are stationary. And such a measurement is performed in all the measurement positions.

  On the other hand, the light distribution characteristic may be measured while rotating at least the arm 22 at a constant angular velocity without being stationary.

  FIG. 9 is a schematic diagram showing a temporal change in the rotation angle when measuring the light distribution characteristic using the measuring apparatus according to the present embodiment. Referring to FIG. 9, arm 22 is continuously rotated once in a state where rotation angle θ (for example, 0 °) of light source 2 is set to a value corresponding to each measurement position. That is, the rotation angle φ of the arm 22 is changed at a constant angular velocity from 0 ° to 360 °. Each time the rotation angle φ of the arm 22 increases by a predetermined value (for example, 5 °), a trigger for instructing the detection unit 40 to start measurement is given. For example, a trigger instructing the start of measurement is output at the timing when the rotation angle φ of the arm 22 coincides with 0 °, 5 °, 10 °, 15 °,. When this trigger is output, the detection unit 40 opens the gate for a predetermined time (exposure time) and receives incident light. That is, the detection unit 40 starts exposure of the light receiving element each time a trigger is given.

  Thus, the measurement is performed with the light source 2 stopped at every predetermined angle. In addition, when the time required for the rotation of the light source 2 by the horizontal rotation stage 12 cannot be ignored, the light source 2 may be rotated while the arm 22 rotates once. That is, the measurement of a certain rotation angle θ of the light source 2 is performed while the arm 22 makes one rotation, the light source 2 is rotated by a predetermined angle during the subsequent rotation, and the new rotation angle θ is further rotated during the subsequent rotation. Measurement is performed. By adopting such a method, it is not necessary to stop the rotation of the arm 22 by the vertical rotation stage 28 and measurement can be performed by continuously rotating the arm 22.

  However, if the exposure time is relatively long, the arm 22 may rotate relatively large between the start and end of exposure. In such a case, it is preferable to employ the following processing procedure.

  FIG. 10 is a diagram for describing a processing procedure when measuring light distribution characteristics using the measuring apparatus according to the present embodiment. As shown in FIG. 10, when exposure is started at a timing when the rotation angle θ reaches a predetermined value while the arm 22 is rotated at a constant angular velocity, a certain degree of angular deviation occurs at the end of exposure.

  On the other hand, the light source 2 is rotated along the first rotation axis AX1 by the horizontal rotation stage, and the cross section of the measurement target of the light source 2 changes by a predetermined angle. FIG. 10 shows a case where the rotation angle θ along the first rotation axis AX1 of the light source 2 is 0 ° and 180 °.

  When the rotation angle θ of the light source 2 is 0 °, it is assumed that the exposure is started at the timing when the rotation angle φ along the second rotation axis AX2 becomes 0 ° and 180 °, respectively. Similarly, when the rotation angle θ of the light source 2 is 180 °, it is assumed that exposure is started at the timing when the rotation angle φ along the second rotation axis AX2 becomes 0 ° and 180 °, respectively. Between the rotation angle θ = 0 ° and the rotation angle θ = 180 °, the direction of relative movement with respect to the light source 2 caused by the rotation of the arm 22 is opposite.

  Therefore, when the rotation angle θ of the light source 2 is 0 °, the measurement result obtained when the exposure is started when the rotation angle φ of the arm 22 is 0 °, and when the rotation angle θ of the light source 2 is 180 °. The measurement result obtained by combining the measurement result obtained when the exposure is started when the rotation angle φ of the arm 22 is 180 ° is the target measurement position (in this case, the rotation angle θ = 0 ° and the rotation angle φ). = 0 °), which corresponds to integration over an equiangular range.

  Similarly, when the rotation angle θ of the light source 2 is 0 °, the measurement result obtained when the exposure is started when the rotation angle φ of the arm 22 is 180 ° and the rotation angle θ of the light source 2 is 180 °. , The measurement result obtained by combining the measurement result acquired when the exposure is started when the rotation angle φ of the arm 22 is 0 ° is the target measurement position (in this case, the rotation angle θ = 0 ° and the rotation angle). This corresponds to integration of an equiangular range centered on (φ = 180 °).

  In this way, even when the time from when the trigger for instructing measurement is output (exposure start) until the end of exposure cannot be ignored, two measurement results in which the rotation angle θ of the light source 2 differs by 180 ° By combining, errors due to the time lag can be reduced. That is, the measurement method according to the present embodiment includes processing for combining a plurality of measurement results corresponding to each other.

  The exposure time of the detection unit 40 is adjusted according to the required sensitivity, but if the exposure time is the same between two points where the rotation angle θ of the light source 2 is different by 180 °, the measurement caused by the exposure time Decrease in accuracy can be prevented.

  FIG. 11 is a flowchart showing a processing procedure when light distribution characteristics are measured using the measuring apparatus according to the present embodiment. Referring to FIG. 11, the user attaches light source 2 to the measurement apparatus (step S100). Normally, the light source 2 is maintained in the lit state (aging) for a predetermined period until it is lit stably.

  Subsequently, the user operates the processing device 300 and gives an instruction to start measurement. Then, the processing apparatus 300 gives a control command to the horizontal rotation stage 12 and rotates the light source 2 until the rotation angle θ along the first rotation axis AX1 becomes an angle corresponding to the first measurement position (step). S102). Then, the processing apparatus 300 gives a control command to the vertical rotation stage 28 to continuously rotate the arm 22 at a constant angular velocity (step S104).

  When rotation angle φ of arm 22 reaches the rotation angle of the measurement target (YES in step S106), processing device 300 outputs a trigger instructing measurement start to detection unit 40 (step S108) and detection. The measurement result from the unit 40 is stored in association with the rotation angle θ and the rotation angle φ at the timing when the trigger is output (step S110). Until the arm 22 makes one rotation, the processes of steps S106 and S106 to S110 are repeated.

  When the arm 22 makes one revolution (YES in step S112), it is determined whether or not the light source 2 has made one revolution along the first rotation axis AX1 (step S114). If the light source 2 has not made one rotation along the first rotation axis AX1 (NO in step S114), the processing device 300 gives a control command to the horizontal rotation stage 12 and follows the first rotation axis AX1. The light source 2 is rotated until the rotation angle θ reaches an angle corresponding to the next measurement position (step S116). And the process after step S106 is repeated.

  If light source 2 has made one rotation along first rotation axis AX1 (YES in step S114), processing device 300 gives a control command to vertical rotation stage 28 to stop the rotation of arm 22 ( Step S118). Then, the processing device 300 calculates the light distribution characteristics of the light source 2 based on the set of the rotation angle θ and the rotation angle φ stored in the measurement process and the measurement result (step S120). In this light distribution characteristic calculation processing, the synthesis processing described with reference to FIG. 10 may be performed. Then, the process ends.

[Conclusion]
The measuring apparatus according to the present embodiment employs the optical fiber 26 as a part of the incident optical system that guides the light from the light source 2 to the detection unit 40. Even if the arm 22 to which the optical fiber 26 is fixed is rotated in order to guide the light propagating through the optical fiber 26 to the detecting unit 40 provided on the second rotation axis AX2 using the optical path changing unit, the optical fiber It is possible to prevent the rotation 26 from being twisted or stressed. Thereby, high measurement accuracy can be maintained.

  In the measuring apparatus according to the present embodiment, since the lighting posture of the light source 2 being measured can be maintained constant, it is possible to prevent changes in optical characteristics during measurement due to changes in heat dissipation conditions. For example, in LED bulbs and the like, the heat dissipation condition changes depending on the lighting posture, and the light characteristics change.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  2 Light source, 4 base portion, 10 first support column, 12, 80 horizontal rotation stage, 14 housing, 20 second support column, 22 arm, 24 integrating sphere, 25 diffuse reflection layer, 26 optical fiber, 27 fixture, 28 Vertical rotation stage, 30, 50 optical path conversion unit, 31, 52 mirror, 32 field of view, 34 counterweight, 38 incident optical system, 40 detection unit, 60 light absorption unit, 62 support member, 70 second vertical rotation stage, 100, 100A, 100B, 200 Measuring device, 124, 284 Pulse motor, 126, 286 Pulse motor controller, 282 Horizontal rotation axis, 286 Bearing, 300 Processing device, 302 CPU, 304 Display, 306 Network interface (I / F), 308 inputs Part, 310 hard disk, 31 2 Memory, 314 CD-ROM drive, 316 I / O unit, 350 pulse counter.

Claims (7)

A light distribution characteristic measuring device for measuring a light distribution characteristic of a light source,
A first rotation mechanism for rotating the light source along a first axis;
A detector provided on a second axis orthogonal to the first axis;
An arm for guiding light from the light source to the detection unit;
A second rotation mechanism for rotating the arm along the second axis,
The arm is
A first optical path conversion unit that is provided on a virtual plane orthogonal to the second axis and that passes through the center of the light source, and converts the optical path of light from the light source;
A light guide for guiding the light whose optical path has been converted by the first optical path converter;
A light distribution characteristic measuring apparatus comprising: a second optical path conversion unit that is provided on an axis of the second axis and emits light incident through the light guide path in a direction parallel to the second axis.   The arm is provided on the side opposite to the first optical path conversion unit with respect to the light source, and includes a light absorption unit for absorbing light emitted from the light source to the side opposite to the first optical path conversion unit. Furthermore, the light distribution characteristic measuring apparatus of Claim 1 further included.   The third rotation mechanism for rotating the light source along a third axis that is parallel to the second axis and farther from the second optical path changing unit. The light distribution characteristic measuring apparatus according to 1.   The said 2nd optical path conversion part is connected to the said light guide path, and contains the integrating sphere by which the extraction window was provided on the axis | shaft of the said 2nd axis | shaft. Light distribution characteristic measuring device.   The light distribution characteristic measuring apparatus according to claim 1, wherein the second optical path conversion unit includes a mirror provided on the axis of the second axis.   The light distribution characteristic measurement device according to claim 1, wherein the detection unit includes a spectroscopic measurement device. A light distribution characteristic measuring method for measuring a light distribution characteristic of a light source,
Arranging the light source at a predetermined angle along a first axis;
Rotating an arm for guiding light from the light source to a detection unit provided on a second axis orthogonal to the first axis along a second axis orthogonal to the first axis; The arm is provided on a virtual plane orthogonal to the second axis and passing through the center of the light source, and converts the optical path of light from the light source, and the first A light guide that guides the light whose light path has been converted by the optical path converter, and the light that is incident on the second axis and is emitted in a direction parallel to the second axis. A second optical path changing unit,
A method for measuring light distribution characteristics, comprising: measuring light from the light source by the detection unit.

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