JP2008304297A - Omnidirectional sensor and device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an omnidirectional sensor capable of simultaneously extracting the direction of an azimuthal magnetic needle operated by a terrestrial magnetism and the inclination to the direction of gravity by a simple method. <P>SOLUTION: In this omniderectional sensor, the surface of a sphere, inside of which a directional magnet 16 and a weight 17 are present, is reflection-treated and the surface of a sphere, enclosing the sphere, is scattering-treated, while an absorption pattern which suitably prohibits the light to transmit is arranged on the surface. This sphere is floated in a light shielding housing 13 which is filled with a transparent liquid and has a transmission window 12 on an incident side and a transmission window 19 on an emitting side to convert the light emitted from the transmission window 19 on the emitting side to electric signals by a photoelectron conversion element 18. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an azimuth sensor that electrically extracts a magnetic azimuth direction generated by geomagnetism and an apparatus using the azimuth sensor, and in particular, an omnidirectional sensor used for a navigation system apparatus with a GPS (omnidirectional earth system) function. It is about.

  Conventionally, the direction of the magnetic field generated by the geomagnetism can be easily grasped by the naked eye based on the direction of the azimuth magnetic needle. However, in order to rotate the electronic display monitor map screen displayed on the navigation device with GPS function in a normal direction according to the traveling direction, it is necessary to electrically extract the direction of the magnetic compass as a digital signal. is there.

On the other hand, in Japanese Patent Laid-Open No. 6-82253, light from a light-emitting element is blocked by a light-emitting element, a light-receiving sensor, and a minute light-shielding small sphere disposed inside a case provided with a plurality of openings, and a plurality of postures are provided. A technique of a posture detecting device for detecting the above is disclosed.
JP-A-6-82253 (first page, FIG. 2)

  However, in the conventional method of detecting a plurality of postures by blocking the light from the light emitting element by a small light blocking sphere, the posture direction is erect, left-tilted, right-tilted, forward-tilted, successor, inverted. Only six directions were recognized, and it was impossible to accurately recognize the directions in all directions. Therefore, an object of the present invention is to provide an omnidirectional sensor capable of accurately recognizing an azimuth continuously in all directions.

  The omnidirectional sensor of the present invention is an omnidirectional sensor including a sphere in which an azimuth magnet and a weight are incorporated, and a housing that holds the sphere so as to be movable, and the surface of the sphere guides light. It has a function and has an absorption pattern that absorbs light on at least a part of its surface, and the housing has an incident-side transmission window through which light enters and an emission-side transmission window through which light exits. Light incident from the window guides the surface of the sphere, is emitted from the exit-side transmission window, and converts the emitted light into an electrical signal.

  The absorption pattern is arranged on the surface of the sphere so that the amount of light that guides the surface of the sphere varies depending on the orientation. The sphere has an inner core sphere whose surface is subjected to reflection treatment, and a light guide layer having a scattering function on the surface is provided outside the inner core sphere. The spherical body is made of resin. Further, the housing is filled with a transparent liquid, and the sphere is held movably. Further, the present invention is an apparatus using this omnidirectional sensor.

  By using the omnidirectional sensor of the present invention, the magnetic field azimuth generated by geomagnetism and the inclination with respect to the direction of gravity can be simultaneously converted into an electrical signal by a photoelectric conversion system using a simple optical system, so that the azimuth can be sensed continuously. Is possible. In addition, the miniaturization of the sensor itself and the use of an electrical signal for the azimuth allow the map image and aerial satellite image on the monitor to be quickly rotated according to the azimuth, and the accuracy is not impaired even if the device is tilted. Can provide high-performance bearing devices and navigation devices. Since only a small number of photoelectric elements are required, the photoelectric element and a complicated circuit board for mounting the photoelectric element can be simplified.

  Hereinafter, embodiments of the present invention will be described in detail. The function of the azimuth | direction apparatus using the omnidirectional sensor of this invention is demonstrated based on FIG. The azimuth | direction apparatus 51 using this invention can perform the position of the person who has an azimuth | direction apparatus, and the advancing direction display 52 on the map monitor-53 on an electronic display by GPS function. This is because the omnidirectional sensor 54 incorporated in the azimuth device 51 outputs the direction of geomagnetism as an electrical digital signal, and rotates the map screen on the electronic display monitor in a normal direction according to the traveling direction. is there.

  Next, the omnidirectional sensor of the present invention will be described in detail as an example. FIG. 1 is a schematic diagram showing the structure of an omnidirectional sensor of the present invention. Reference numeral 11 denotes a red LED that outputs light from a light source, and emits light at 300 mw of 0.1 A at 3V. The light shielding casing 13 is provided with a 3 mmφ incident side transmission window 12 through which light from a light source is incident. The light shielding housing 13 is filled with a transparent liquid benzene, and a sphere 14 having a light guide function on the surface is movably floated. The spherical body 14 includes a fixed compass 16 and a brass weight 17.

  The spherical body 14 is provided with a gap between the light shielding housing 13 and the spherical body 14 so as to freely rotate in the light shielding housing 13. However, it is preferable to design the gap as small as possible so that the light incident from the incident-side transmission window 12 enters the approximate center of the sphere 14. Further, if the specific gravity of the sphere 14 and the transparent liquid is made substantially equal, the sphere 14 can be held in a substantially fixed position by the weight and the azimuth magnet even if the light shielding casing 13 changes in all directions. is there. Further, the light shielding casing 13 is provided with two emission side transmission windows 19. The number of the exit side transmission windows 19 may be one, but the accuracy of the sensor can be improved by providing a plurality of the exit side transmission windows 19.

  FIG. 2 is a schematic diagram showing an absorption pattern on the surface of the sphere 14. This absorption pattern is a dot-like black halftone dot pattern. The black halftone dot pattern per unit area of the surface is changed so that the amount of light guided through the surface of the sphere 14 varies depending on the orientation, and the surface of the sphere 14 is changed. A plurality of black halftone dot patterns are provided with each distribution. 2 shows a black halftone dot pattern as viewed from the side surface of the sphere 14. In the <schematic diagram of the top surface pattern> of FIG. 2, a black halftone dot pattern viewed from the upper pole side of the sphere 14 is shown. As shown in these schematic diagrams, the arrangement distribution density of the black halftone dot pattern is increased near the upper pole and the vicinity of the lower pole, and the arrangement distribution density is decreased near the equator. Also, in the vicinity of the extreme point, as shown in <Schematic diagram of upper surface pattern>, the arrangement density of the black halftone dot pattern is gradually changed around the extreme point. Although not shown, the arrangement density of the black halftone dot pattern is gradually changed even near the poles on the lower surface. At this time, it is preferable to change the arrangement distribution from dark to light by reverse rotation from the vicinity of the pole on the upper surface.

  FIG. 3 is a view showing a cross section of a sphere. The spherical body is an acrylic resin 36 having an outer diameter of 1 cmφ and a hollow center. Further, an inner core sphere made of a hollow acrylic resin 36 is provided inside the sphere. The inner core sphere is stored inside the sphere so that it does not move inside the sphere. An azimuth needle 34 and a brass weight 35 are fixed inside the cavity of the inner core sphere with an acrylic adhesive. The surface of the inner sphere is coated with a white paint to form a reflection processing unit 33 having a reflection function. Further, the surface of the sphere is blasted to form a frosted glass-like blasting portion 32 and has a scattering function for scattering light incident on the sphere. Thus, since the surface of the sphere has a scattering function, the layer of the acrylic resin 36 and the blast processing unit 33 provided on the outermost surface of the sphere has a light guiding function. Further, the black halftone dot pattern 31 described above is formed on the outermost surface of the sphere by intaglio printing.

  FIG. 4 is a schematic cross-sectional view showing a state where light incident on the sphere is guided. The red incident light 40 incident from the incident side transmission window of the light shielding casing is reflected by the reflection processing unit 43 on the outer surface of the inner core sphere, and is guided by the blast processing unit 43 that is the surface of the sphere and the acrylic resin layer. And repeat propagation. The propagated light is absorbed at the place where the black halftone dot pattern 41 is arranged, is not emitted outside the sphere, and is emitted as the outgoing light 44 outside the sphere at the place where the black halftone dot pattern 41 is not arranged. The The emitted light 44 is emitted from a plurality of emission-side transmission windows provided in the light shielding casing, and the light amount is converted into a current value by the photoelectric conversion element 48 disposed outside the emission-side transparent window, and is measured. The relationship between the light amount and the azimuth is obtained in advance, and the azimuth can be obtained from the current value of the emitted light.

  Thus, an omnidirectional sensor can be obtained by providing the sphere illustrated in FIG. 3 in the light shielding casing 13 as illustrated in FIG. As shown in FIG. 1, the red light applied to the sphere 14 repeatedly propagates on the surface of the inner core sphere 15 subjected to the reflection process, and the emission distribution varies depending on the black halftone dot pattern. The light intensity received by the photoelectric conversion element 18 varies depending on the orientation. Such light intensity can be digitized by the photoelectric conversion element 18 to obtain the orientation of the omnidirectional sensor.

  In the case of this example, the value of the current flowing through the photoelectric conversion element on the bottom side of the housing was 6 to 12 microamperes. The current value flowing through the photoelectric conversion element on the side surface side was 15 to 35 amperes.

  Therefore, as shown in FIG. 1, a difference in strength occurs in the current flowing through the photoelectric conversion element depending on the direction of the light shielding casing 13, and in addition to the difference in strength of the current value, the comparison of the ratio of the current value between the photoelectric elements, The inclination with respect to the direction of gravity is output as an electric signal at the same time as the geomagnetic field direction. That is, the photoelectric conversion current is converted into a voltage, amplified by AMP, subjected to azimuth calculation by MPU (microprocessor unit) after A / D conversion, and an azimuth signal including a gravity direction is output as a digital signal.

It is a schematic diagram which shows the structure of the omnidirectional sensor of this invention. It is a schematic diagram which shows the surface pattern of the spherical body of this invention. It is a schematic cross section of the sphere of the present invention. It is the schematic cross section which showed the path | route of the incident light of this invention. It is a schematic diagram which shows the structure of the azimuth | direction apparatus using the inclination sensor of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Light source 12 Incident side transmission window 13 Shading case 14 Sphere 15 Inner core ball 16 Directional magnet 17 Weight 18 Photoelectric conversion element 19 Output side transmission window 31 Black halftone dot pattern 32 Blast processing part 33 Reflection processing part 34 Directional magnet 35 Weight 36 Acrylic Resin 51 Directional device 52 Travel direction display 53 Map monitor 54 Omnidirectional sensor

Claims (6)

A sphere with a compass and weight,
An omnidirectional sensor comprising a housing for holding the sphere so as to be movable;
The surface of the sphere has a light guide function of guiding light, and has an absorption pattern that absorbs light on at least a part of the surface,
The housing has an incident-side transmission window through which light enters and an emission-side transmission window through which light exits,
The omnidirectional sensor characterized in that light incident from the incident side transmission window is guided through the surface of the sphere, is emitted from the emission side transmission window, and converts the emitted light into an electrical signal.   2. The omnidirectional sensor according to claim 1, wherein the absorption pattern is arranged on a surface of the sphere so that an amount of light guided on the surface of the sphere is different depending on a direction.   The sphere has an inner core sphere having a reflection-treated surface, and a light guide layer having a scattering function on the surface is provided outside the inner sphere. Omnidirectional sensor.   The omnidirectional sensor according to any one of claims 1 to 3, wherein the sphere is made of a resin.   The omnidirectional sensor according to any one of claims 1 to 4, wherein the casing is filled with a transparent liquid and the sphere is movably held.   The apparatus using the omnidirectional sensor as described in any one of Claim 1 to 5.

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