JP2009222441A - Retroreflective intensity measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retroreflective intensity measuring device for simply measuring reflection properties, reflection distribution of reflected light, wavelength distribution of reflected light, etc. without cutting out a sample, when an incident direction changes. <P>SOLUTION: The retroreflective intensity measuring device includes a light source, a light receiving part, optical fiber, and a turning part for turning the head of the optical fiber. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a retroreflective intensity measuring device used for evaluating the retroreflective performance of a material surface such as a paint or a sheet, and more specifically, the angle dependency, distribution, wavelength dependency, etc. of the material surface such as a paint or sheet. The present invention relates to a retroreflective intensity measuring device used for evaluating the characteristics of retroreflective performance.

  The retroreflective material is a material having a property of reflecting light emitted from the light source toward the light source. Retroreflective materials are widely used for road signs and signboards, for example. The retroreflective material must have sufficient reflective properties due to the nature of its application. The reflection performance of the retroreflective material is defined in, for example, JIS Z8714 (1995) “Retroreflector-Optical Measurement-Measurement Method” and JIS Z9117 (1984) “Security Reflective Sheet and Tape”.

  In recent years, attempts have been made to use retroreflective materials such as retroreflective tiles and retroreflective coatings on buildings and automobile surfaces. By using a retroreflective material on the surface of a building or automobile, it is possible to reduce the influence on the surroundings that becomes a problem in the case of specular reflection. When constructing a retroreflective material at a construction site where the surface shape is complex, more effective construction is possible by constructing the retroreflective material while measuring the reflection performance of the retroreflective material. Further, when measuring the reflection performance of the retroreflective material for such a purpose, it is not sufficient to measure the reflection performance of light incident from a direction substantially perpendicular to the surface of the retroreflective material. For example, the incident direction of sunlight is daily and annual. In such a case, in order to measure the reflection performance of the retroreflective material according to the actual situation, simply measure the reflection performance when the incident direction changes, the reflection distribution of reflected light, the wavelength distribution of reflected light, etc. There is a need to.

  The method for measuring the reflection performance of the conventional retroreflective material described above targets signs and signs. For this reason, the measurement of reflection performance requires a large space. Therefore, it is not suitable for simply measuring the reflection performance at the construction site. Moreover, it is necessary to cut out and measure a sample, and it cannot be applied while measuring the reflection performance of the retroreflective material.

  For example, the following devices have been proposed as retroreflective performance measuring devices (see, for example, Patent Documents 1 to 3).

  In the apparatus described in Patent Document 1, a retroreflective performance measuring apparatus capable of measuring the reflective performance of a retroreflective material in a space-saving manner without cutting out a sample has been proposed. This retroreflective performance measuring apparatus reflects light from a light source by a reflecting member, irradiates the measurement sample, and measures the luminous intensity of the reflected light transmitted through the reflecting member. That is, in this retroreflection performance measuring apparatus, the light source, the reflecting member, and the light receiving element need to have a certain positional relationship. For this reason, in order to measure the reflection performance when the incident direction changes, the reflection distribution of reflected light, etc., there is a problem that the positional relationship is not easily adjusted.

  In the apparatus described in Patent Document 2, an LED is used as the light source to prevent the light beam diameter of the irradiated light from becoming large, an optical fiber is used as the light projecting / receiving part, and light is projected concentrically around the light receiving fiber. A fiber is arranged to reduce the size of the apparatus and improve the measurement accuracy. However, with this apparatus, it is necessary to cut out and measure a sample. In addition, since it is designed to measure the reflection performance of light that is incident almost vertically, the reflection performance when the incident direction changes easily, the reflection distribution of reflected light, the wavelength distribution of reflected light, etc. Not suitable for measurement.

In the apparatus described in Patent Document 3, an optical fiber, a mirror, and a convex lens are combined to bend an optical path, and a light shield is used to reduce the amount of scattered light that becomes noise. However, with this device, the optical path is bent by combining an optical fiber, a mirror, and a convex lens, so the positional relationship can be easily adjusted to measure the reflection performance when the incident direction changes, the reflection distribution of reflected light, etc. There is a problem that is not.
JP 2002-206989 A Japanese Patent Laid-Open No. 10-115549 JP 2000-503395 gazette

  That is, the present invention has been made in view of the above problems, and its purpose is to simplify reflection performance, reflection distribution of reflected light, wavelength distribution of reflected light, and the like when the incident direction changes without cutting out a sample. It is an object of the present invention to provide a retroreflective intensity measuring device for measuring in the first place.

  As a result of intensive studies to solve the above problems, the present inventors have completed the following invention. That is, the present invention is as follows.

  The retroreflective intensity measuring device of the present invention includes a light source, a light receiving unit, an optical fiber, and a rotating unit that rotates the head of the optical fiber.

  In other words, in the present invention, the optical fiber head is rotated using the rotating portion. Specifically, the optical fiber head is rotated so as to change the angle (light projection angle) formed by the extension line of the tip of the optical fiber head (portion for projecting and receiving light) and the sample surface. Thereby, the light projection angle to the sample surface of the optical fiber can be changed. As a result, the angle-dependent retroreflection intensity can be measured.

  The retroreflective intensity measuring device includes moving means for moving the head of the optical fiber or the sample. Thereby, the surface distribution of the retroreflection intensity on the sample surface can be measured while maintaining the projection angle and the distance.

  The light receiving unit is a photodiode, a phototransistor, or a spectroscope. With this configuration, the retroreflective wavelength distribution on the sample surface or the value in a specific wavelength range can be measured.

In the retroreflective intensity measuring device of the present invention, the optical fiber head is rotated using the rotating unit so as to change the projection angle from the optical fiber. By rotating the optical fiber as described above, the reflection performance when the incident direction is changed can be measured with a simple configuration without cutting out the sample.
In addition, a moving means for moving the head or sample of the optical fiber integrated with the light projecting and receiving unit is provided. As a result, it is possible to measure the reflection distribution of the reflected light according to the change in surface characteristics.
Furthermore, in the present invention, the light receiving part can be easily replaced. As a result, it is possible to measure the wavelength distribution of the reflected light and the value in a specific wavelength range by changing the measurement conditions.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram for explaining the outline of the retroreflective intensity measuring apparatus of the present invention.

  As shown in FIG. 1, the retroreflective intensity measuring device of the present invention includes a light source 1, a light receiving unit 2, an optical fiber 3, and a rotating unit 5. The rotating unit 5 rotates the head of the coaxial optical fiber integrated with the light projecting / receiving unit with the tip of the coaxial optical fiber head 4 integrated with the light projecting / receiving unit being at the center and the other end of the head being the peripheral side. Move.

  The optical fiber that can be used in the present invention is not particularly limited as long as it can project and receive light, and known optical fibers such as a coaxial type, a parallel type, and a split type can be used. These optical fibers may be used as appropriate according to the purpose of use. For example, a coaxial type optical fiber is used for precise measurement, and a parallel type or split type optical fiber is used for simple measurement.

  FIG. 2 is a cross-sectional view of a head portion of a coaxial optical fiber integrated with a light emitting / receiving unit when a coaxial optical fiber integrated with a light projecting / receiving unit is used in the present invention. As shown in FIG. 2, the optical fiber head 4 includes a plurality of light projecting optical fibers 9 on a concentric circle and a light receiving optical fiber 8 at the center of the concentric circle. As the coaxial optical fiber integrated with light emitting and receiving, fibers having different concentric radii may be used. In a conventional retroreflective intensity measuring device, the angle of retroreflection or the like is adjusted using a lens or the like. However, when using a coaxial optical fiber integrated with light emitting and receiving, it is easy to adjust the angle of the retroreflection by adjusting the radius of the concentric circle and the distance between the tip of the optical fiber head and the sample surface. Yes. The light projecting / receiving integrated coaxial optical fiber that can be used is not limited to this configuration, and may have two or more concentric circles. In this way, by using the coaxial optical fiber integrated with light emitting and receiving, the retroreflected light intensity can be measured with a simple configuration. The outer diameter of the head 4 of the coaxial optical fiber is about 1 to 6 mm.

  The projecting optical fiber 9 has one end facing the sample and the other end connected to the light source 1. The light receiving optical fiber 8 is connected to the light receiving element 2. In the example of FIG. 1, a light source / light receiving element integrated type is used for the simplicity of the apparatus. The configuration is not limited to this, and a light source and a light receiving element separated may be used.

  As the light source 1, a known light source such as an LED (light emitting diode), an LD (laser diode), or a halogen lamp can be used. In the present invention, by replacing the light source 1 connected to the optical fiber 9 for light projection, the retroreflection intensity by the light source according to the purpose of measurement can be easily measured.

  The light receiving optical fiber 8 has one end facing the sample and the other end connected to the light receiving unit 2. As the light receiving unit 2, a light receiving element such as a photodiode, a phototransistor, or a spectroscope can be used according to the purpose of measurement. In the present invention, the light receiving element connected to the light receiving optical fiber can be easily replaced. Thereby, it is possible to easily measure the retroreflection intensity depending on the wavelength such as the visible light region and the near infrared region.

  A voltmeter 6 is connected to the light source 1 and the light receiving unit 2. Thereby, conditions, such as the intensity of the light projected from a light source, can be adjusted. Further, a gain adjustment circuit may be provided between the light source 1 or the light receiving element 2 and the voltmeter 6. Light whose light intensity is adjusted by adjusting the voltage is projected from the light source 1. This light passes through the light projecting optical fiber 9 and is irradiated onto the surface of the sample 7. The reflected light reflected from the sample surface is transmitted from the light receiving optical fiber 8 to the light receiving unit 2. Light having a wavelength corresponding to the characteristics of the light receiving element constituting the light receiving unit 2 is received by the light receiving element. By measuring the intensity of the received light with the voltmeter 6, the retroreflection intensity can be measured. In the example of this figure, the voltmeter 6 is used. However, the voltmeter 6 is not limited to the voltmeter as long as the adjustment of the emitted light intensity and the intensity of the received light can be changed to other signals.

  In the present invention, one feature is that the rotating unit 5 is provided in the coaxial optical fiber for light projection. As shown in FIG. 3, the rotating unit 5 rotates the optical fiber head so as to change the projection angle from the optical fiber with respect to the surface of the sample 7. In this way, the coaxial optical fiber head 4 integrated with the light projecting / receiving unit rotates. The irradiation distance is such that the distance h between the front end portion of the coaxial optical fiber head 5 integrated with the light projecting / receiving unit and the surface of the sample 7 when dropped in the vertical direction is that of the integrated light projecting / receiving unit when dropped vertically. This is the distance h ′ between the tip of the coaxial optical fiber head 5 and the surface of the sample 7. However, the difference between the distances h and h 'is eliminated by mathematically correcting the measurement result. For example, the reflection performance of light whose incident direction changes, such as sunlight, can be easily measured.

  The rotating part 5 is not particularly limited, and may be any structure having a base, a movable part, and a shaft connecting the base and the movable part. The optical fiber head 5 is fixed to this movable part. The optical fiber head can be rotated by moving the movable part about the axis. Moreover, what is necessary is just to make this rotation part 5 interlock | cooperate with an angle meter or a rotary variable resistor, for example. According to this configuration, the angle of rotation can be easily measured by moving the movable part. Further, the movable part may be moved manually or a drive device may be used.

  The retroreflective intensity measuring apparatus of the present invention may include a moving means 10 for moving the head or the sample of the light projecting / receiving integrated optical fiber. With this configuration, even if the sample has a large area, the head of the optical fiber can be moved two-dimensionally on the sample, or the sample can be moved two-dimensionally. By moving the moving means 10 in this way, the retroreflection intensity over a wide range can be easily measured. As a result, the distribution of the retroreflective intensity on the sample surface can be measured.

  The moving means 10 may move the head 5 of the light projecting / receiving integrated optical fiber as shown in FIG. 4, or may move the sample as shown in FIG.

  The moving means 10 uses a moving means such as a movable table with wheels attached thereto, a traverse device that moves horizontally with the sample wall surface while maintaining a constant distance from the sample, and the head of the optical fiber together with the rotating part, the sample As long as it can move. A sliding volume or the like may be connected to these moving means. Thereby, a movement amount and a moving direction can be adjusted easily. With this configuration, the angular mobility of the retroreflection intensity and the surface distribution can be measured simultaneously.

  Thus, the retroreflective intensity measuring apparatus of the present invention can measure the retroreflective intensity under various conditions with a simple configuration. As a result, it is possible to easily measure the reflection performance when the incident direction changes, the reflection distribution of reflected light, the wavelength distribution of reflected light, and the like. In addition to these configurations, a configuration such as a correction unit for performing more accurate measurement may be arbitrarily added and used.

FIG. 1 is a diagram for explaining the outline of the retroreflective intensity measuring apparatus of the present invention. FIG. 2 is a cross-sectional view of a head portion of a coaxial optical fiber integrated with light emitting / receiving used in the present invention. FIG. 3 is a diagram for explaining a state in which the head of the optical fiber is rotated in the retroreflective intensity measuring device of the present invention. FIG. 4 is a diagram for explaining a state in which the head of an optical fiber integrated with light emitting and receiving is moved horizontally in the retroreflective intensity measuring device of the present invention. FIG. 5 is a diagram for explaining a state in which the sample is moved horizontally in the retroreflective intensity measuring device of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Light-receiving part 3 Optical fiber of light projection / reception integral type 4 Head of optical fiber 5 Rotating part 6 Voltmeter 7 Sample 8 Optical fiber for light projection 9 Optical fiber for light reception 10 Moving means

Claims (3)

A light source;
A light receiver;
Optical fiber,
A retroreflective intensity measuring device comprising: a rotating unit that rotates the head of the optical fiber. The retroreflective intensity measuring device is
The retroreflective intensity measuring apparatus according to claim 1, further comprising moving means for moving the head or sample of the optical fiber. The retroreflective intensity measuring apparatus according to claim 1, wherein the light receiving unit is a photodiode, a phototransistor, or a spectroscope.

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