JP2015219206A - Optical marker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical marker capable of discriminating disturbance light from the optical marker from light or reflection light and improving the light visual recognition accuracy of the optical marker.SOLUTION: An optical marker comprises: a light source 11; and a cover portion 12 cylindrically formed out of a polarization filter at an angle of 45 degrees with respect to a central axis of a cylinder; and a cover portion 12 disposed on an outer circumference of the light source 11.

Description

  The present invention relates to an optical marker that emits light.

  In recent years, three-dimensional measurement has been used in various fields (see, for example, Patent Document 1). In three-dimensional measurement for specifying a three-dimensional shape or the like, there is a method using a reflective marker. Specifically, a reflective marker is affixed to the reference point of the object for three-dimensional measurement, an image is taken by irradiating the reflective marker with light, the position of the light is identified from the taken image, and finally There is a method for obtaining a three-dimensional shape. There is also a method in which a light emitter is attached to a reference point of an object, a light emitter that emits this light is photographed, a position thereof is specified from the photographed image, and finally a three-dimensional shape is obtained.

  In addition, conventionally, there are things such as signal towers that try to convey various messages to users by emitting light and using the emitted color and method (see, for example, Patent Document 2).

  However, conventionally, it has been difficult to specify light to be emitted. For example, in three-dimensional measurement, it may be difficult to discriminate light indicating a reference point by disturbance light or reflected light, and it may be difficult to determine light emitted by disturbance light or reflected light even in a signal tower.

JP 2010-014546 A JP-A-11-184418

  As described above, the conventional light emission has a problem that the actually required light emission cannot be distinguished due to the influence of disturbance light or reflected light.

  In view of the above problems, an object of the present invention is to provide an optical marker that emits distinguishable light.

  In order to achieve the above object, the invention according to claim 1 is a cover portion that is formed in a cylindrical shape by a light source and a polarizing filter having an angle of 45 degrees with respect to the central axis of the tube, and is disposed on the outer periphery of the light source With.

  The invention of claim 2 includes a light source and a cover portion formed in a cylindrical shape by a circularly polarizing filter and disposed on the outer periphery of the light source.

  In the invention of claim 3, the cover part is formed in a cylindrical shape.

  According to the present invention, it is possible to improve the light viewing accuracy of the optical marker.

It is the schematic explaining the structure of the optical marker which concerns on 1st Embodiment. It is a figure explaining the filter part utilized with the optical marker of FIG. It is another figure explaining the polarization of the light in the optical marker of FIG. It is a graph showing the transmittance | permeability of light and the angle difference of polarized light. It is the schematic explaining the interruption | blocking of the light at the time of utilizing the optical marker of FIG.

  Below, the optical marker which concerns on each embodiment of this invention is demonstrated. The optical marker according to the present invention is light emitted from a light source, and makes it possible to specify the position of the optical marker and the presence or absence of light emission. For example, three-dimensional measurement is possible using an image including the light emission position of the optical marker. Or the light of this optical marker can also be used as the light of a signal tower.

[First Embodiment]
As shown in FIG. 1A, the optical marker 1 according to the embodiment of the present invention is formed in a cylindrical shape by a light source 11 and a polarizing filter having an angle of 45 degrees with respect to the central axis of the cylinder. The cover part 12 arrange | positioned at the outer periphery of this is provided. Although not shown in FIG. 1A, the light source 11 is supported by a support means.

  The light source 11 may be installed in the cover portion 12 and may diffuse light in the entire circumferential direction. For example, like the optical marker 1A shown in FIG. 1B, the LED 11A can be used as a light source. Moreover, you may utilize the diffuse reflection film 11B for a light source like the optical marker 1B shown in FIG.1 (c). For example, the diffuse reflection film 11B can uniformly diffuse the light emitted from the light source in the entire circumferential direction, and the light received in the entire circumference becomes uniform without depending on the position from the optical marker 1. In FIGS. 1B and 1C, only the rear surface of the cover portion 12 is shown, and the front surface is omitted.

  The cover portion 12 is formed in a cylindrical shape with a polarizing filter that transmits light only in a specific polarization direction. In addition, this polarizing filter is preferably formed of an “absorptive” filter rather than a “reflective” filter. The polarizing filter used to generate the cover unit 12 is, for example, a filter having a quadrangular shape and a polarization direction of 45 degrees with respect to the sides l1 and 12 as shown in FIG. With the filter shown in FIG. 2A, a cylindrical shape is formed such that the central axis is parallel to the sides l1 and l2, as shown in FIG. When formed in this way, the polarization directions at two locations (for example, point Y1 and point Y2 in FIG. 2B) that are opposed to each other in the radial direction across the central axis of the cover 12 are shifted by 90 degrees. In addition, in the example shown in FIG.1 and FIG.2, although the cover part 12 is illustrated as what is formed in a cylindrical shape with a polarizing filter, it is not restricted to a cylindrical shape. That is, it is only necessary to form a cylindrical shape with a polarizing filter having an angle of 45 degrees with respect to the central axis of the cylinder.

  Although omitted in FIG. 1, the cylindrical upper and lower opening portions of the cover portion 12 are preferably configured to prevent external light from entering the inside of the optical marker 1. This is to prevent light entering from the outside of the optical marker 1 from being transmitted from the inside of the cover portion 20 to the outside and making it difficult to distinguish the light from the light source 11.

  Further, the outer surface of the cover portion 12 may be subjected to antireflection processing such as AR coating (Anti Reflection Coating) for preventing light reflection. By applying AR coating in this way, reflection of light on the surface of the cover portion 12 can also be prevented. Moreover, the influence of the reflected light from the light source 11 can be reduced by matching the AR coating of the cover part 12 with the wavelength of the light emitted from the light source 11.

  The size of the light marker 1, that is, the size of the light source 11 and the cover portion 12 is not limited, and varies depending on the application.

  FIG. 3A is a top view of the cover portion 12 generated in a cylindrical shape as described with reference to FIG. For example, when the light L enters the cover portion 12 from the outside of the cover portion 12, the polarization of the light L is non-polarized outside the cover portion 12 (for example, the point Y0). When this light L enters the cover part 12, since the polarization direction of the outer surface (point Y1) of the cover part 12 is 45 degrees, the polarization of the light L passing through the point Y1 is 45 degrees. Further, the polarization of the light L is 45 degrees both at the point Y3 in the cover portion 12 and at the inner point Y2 on the cover portion 12. However, as described above, since the polarization directions of the filter point Y1 and the point Y2 are different by 90 degrees, the 45-degree polarized light L that has passed through the point Y1 from the outside to the inside of the cover 12 faces the radial direction. In Y2, the cover portion 12 cannot pass from the inside to the outside.

  At this time, as shown in FIG. 3B, the light having a polarization direction of 45 degrees that has passed through the inside of the cover portion 12 has the strongest light traveling in the linear direction, but diffuses in multiple directions in the cover portion 12. . Accordingly, some of the diffused weak light travels to a wide range such as the point Y21 or the point Y22. At this time, since the deviation of the polarization direction of the filter is not 90 degrees with respect to the point Y1, the light is leaked from the inside of the cover part 12 to the outside. However, the light is weak and the transmittance of light between filters having different polarizations is originally low as shown in FIG. Therefore, there is little light leaking to the outside, and there is little influence when the light emitted from the light source 11 disposed in the cover portion 12 is strong.

  FIG. 4 is a graph showing the light transmittance. In FIG. 4, the horizontal axis represents the angle difference between the polarization of light and the polarization direction of the polarizing filter, and the vertical axis represents the light transmittance. According to the example shown in FIG. 4, the transmittance is 100% when there is no angle difference between the polarization direction of light and the polarization direction of the polarizing filter, but when the angle difference is 45 degrees, the transmittance is 50%, and the angle difference is 90 degrees. It can be seen that light does not pass through.

  FIG. 5 is a diagram for explaining the positional relationship between the light marker 1 and the user 20 using the light marker and the progress of light. As shown in FIG. 5A, it is assumed that disturbance light L2 enters the optical marker 1 that emits light L1 from the light source 11 from the side facing the user 20. If the cover unit 12 is not provided and only the light source 11 is provided, the user 20 cannot distinguish between the light L1 from the light source 11 and the light from the disturbance light L2. However, as described above, even if light is transmitted through the optical marker 1, the polarization direction is shifted by 90 degrees from the point facing the transmission point in the optical marker 1, so that the transmitted light L2 is the optical marker. It cannot penetrate out of 1. Therefore, as shown in FIG. 5A, the disturbance light L2 is not transmitted outside the optical marker 1, but only the light L1 of the light source 11 is transmitted from the optical marker 1, and the user 20 12, only the light L <b> 1 of the light source 11 can be visually recognized.

  Further, as shown in FIG. 5B, it is assumed that the reflector 2 is present at a position facing the user 20 with the optical marker 1 as a reference. The reflector 2 has a property of reflecting light such as a metal or a bright-colored object. In the state as shown in FIG. 5B, since the light emitted from the light source 11 is emitted in the entire circumferential direction, the light passes through the cover portion 12 and travels toward the user 20 and the reflector 2. Continue in the direction of. Further, in the reflector 2, this light is reflected to be transmitted through the cover portion 12. However, since the polarization direction is shifted by 90 degrees between the transmission point where the reflected light reflected by the reflector 2 is transmitted into the cover portion 12 and the point facing this transmission point, the transmitted light is out of the light marker 1. It cannot penetrate outside. Therefore, as shown in FIG. 5B, the reflected light cannot be transmitted to the opposite side of the light marker 1, and only the light from the light source 11 is transmitted from the light marker 1. Only the light of the light source 11 can be visually recognized through the.

  As described above, in the optical marker 1 according to the first embodiment, disturbance light or reflected light of light from the light source 11 leaks from the optical marker 1 by disposing the light source 11 in the cover unit 12 that uses a polarizing filter. And only the light from the light source 11 is visible through the cover 12. Thereby, in the optical marker 1 which concerns on 1st Embodiment, the visual recognition precision of light can be improved.

[Second Embodiment]
The optical marker according to the second embodiment is the same as the optical marker of FIG. 1 in that it includes a light source and a cover unit disposed on the outer periphery of the light source, but a cover unit that uses a polarizing filter. The difference is that a cover portion using a circularly polarizing filter is provided instead of 12. In addition, about the optical marker which concerns on 2nd Embodiment, illustration is abbreviate | omitted and it demonstrates with reference to FIG.1 and FIG.5 (b).

  In addition, the transmitted light that has passed through the circular polarizing filter becomes reflected light in which the circularly polarized rotationally polarized light is reversely directed on the reflecting surface, and is absorbed by the circular polarizing filter. Therefore, as shown in FIG. 5B, even when the light emitted from the light source 11 is transmitted from the inside to the outside of the filter unit and reflected by the reflector 2, the reflected light is not rotationally polarized. Since it becomes reverse direction, it cannot permeate | transmit the inside of a filter part again. Therefore, it is not visually recognized by the user at a position facing the reflector 2 with respect to the optical marker.

  As described above, in the optical marker according to the second embodiment, by arranging the light source in the cover portion using the circular polarization filter, the reflected light of the light from the light source is prevented from leaking from the optical marker, Only light is visible through the cover. Thereby, in the optical marker 1 which concerns on 2nd Embodiment, the visual recognition precision of light can be improved.

  As mentioned above, although this invention was demonstrated in detail using each embodiment, this invention is not limited to embodiment described in this specification. The scope of the present invention is determined by the description of the claims and the scope equivalent to the description of the claims.

1, 1A, 1B ... Light marker 11 ... Light source 11A ... LED
11B ... Diffuse reflective film 12 ... Cover part

Claims (3)

A light source;
A cover formed in a cylindrical shape with a polarizing filter having an angle of 45 degrees with respect to the central axis of the tube, and disposed on the outer periphery of the light source;
An optical marker comprising: A light source;
A cover formed in a cylindrical shape with a circularly polarizing filter and disposed on the outer periphery of the light source;
An optical marker comprising: The optical marker according to claim 1, wherein the cover portion is formed in a cylindrical shape.

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