JP4000376B2 - Object position detection device, object tracking device, and information providing device - Google Patents

Description

  The invention of this application relates to an object position detecting device, an object tracking device, and an information providing device for detecting the position of an object with high accuracy, tracking it, and providing information.

  In recent years, there has been a demand for an information service system that appropriately provides information according to the user's intention and situation in a short-distance closed space such as a room. In this information service system, obtaining the user's position in space with high accuracy is one of the important elements for grasping the user's situation.

For acquisition of the user position, a sensor array is arranged in a grid and determined from the position of the nearest receiving point, a technique using parallax by imaging like a CCD camera (for example, see Non-Patent Document 1), Various methods such as a method of positioning from the arrival time difference of ultrasonic waves or electromagnetic waves to the reception point, a method of positioning by measuring the azimuth and distance (for example, see Non-Patent Document 2) are considered.
T. Nishimura et al., "Compact battery-maintenance-freeinformation terminal (CoBIT) for location-based support systems [4863-12]", Proc. Of SPIE, Java / Jini Technologies and High-PerformancePervasive Computing, Vol.4863, p.80 (2002) H. Itoh et al., "Optoelectronic fuzzy logic interface system using beam scanning laser diodes", TECHNICAL DIGEST of OPTICAL COMPUTING, OWD5-1, pp.123-126 (1993)

  However, in the conventional position detection technology as described above, if the position accuracy is to be as high as within a few centimeters, the number of sensors and the cost of the measuring device are increased.

  Therefore, in view of the circumstances as described above, the invention of this application is based on an inexpensive object position detection device that can detect the position of an object such as a user or an article with high accuracy of several centimeters, and a detected position. It is an object of the present invention to provide an object tracking device that can accurately track an object and an information providing device that can provide information to the object based on a detected position.

  In order to solve the above problems, the invention of this application firstly, a glass rod array in which fluorescent glass rods capable of converting ultraviolet light into visible light are arranged in parallel, and the glass rod array is irradiated with ultraviolet light. And a light receiving element array provided with a light receiving element for receiving visible light emitted from each fluorescent glass rod of the glass rod array, and receiving light of each light receiving element generated when an object blocks ultraviolet light. Provided is an object position detecting device for detecting the position of an object based on a change amount of signal intensity.

  Second, the object position detecting device is characterized in that the light receiving element is a solar cell or a photodiode.

  Third, the object position detecting apparatus is characterized in that the received light signal intensity is either a photovoltage or a photocurrent.

  Fourthly, the object position detecting device is characterized in that fluorescent glass rods are arranged one-dimensionally.

  Fifth, the object position detecting device is characterized in that fluorescent glass rods are arranged in a multidimensional manner.

  Sixthly, an object tracking device is provided, in which tracking light is deflected to the position of the object detected by the object position detection device, and the object is tracked.

  Seventh, there is provided an information providing apparatus for deflecting information light to the position of the object detected by the object position detecting apparatus and providing information to the object.

  According to the first object position detection apparatus, fluorescent glass that converts ultraviolet light into visible light is applied, and for example, a plurality of rod-shaped objects are arranged in an array on a wall surface, floor surface, ceiling surface, or the like. The UV light applied to the fluorescent glass rod is blocked when an object such as a user or article to be detected passes before or under it, and the changes in visible light caused by this change in the received signal intensity of various light receiving elements. By detecting this as a change in the position of the object, the position of the object can be accurately detected based on the amount of change.

  According to the second object position detection device, the same effect as that of the first device can be obtained, and the size and cost of the device can be further suppressed by using a small and inexpensive solar cell or photodiode. .

  According to the third object position detecting device, the same effects as those of the first and second detecting devices can be obtained, and a more responsive change can be achieved by using the photovoltage or photocurrent from the light receiving element. The quantity can be obtained and further highly accurate position detection can be realized.

  According to the fourth object position detection device, the same effects as those of the first detection device can be obtained, and the one-dimensional position of the object can be detected.

  According to the fifth object position detection device, the same effects as those of the first detection device can be obtained, and the two-dimensional or three-dimensional multidimensional position of the object can be accurately detected.

  According to the sixth object tracking device, the same effects as those of the first to fifth detection devices can be obtained, and the object can be accurately tracked by deflecting the tracking light to the detected position. become.

  According to the seventh information providing apparatus, the same effects as those of the first to fifth detecting apparatuses are obtained, and information is accurately provided to the object by deflecting the information light to the detected position. Will be able to continue.

[First Embodiment]
FIG. 1 shows one embodiment of the object position detecting device of the invention of this application having the features as described above, and fluorescent glass rods (10) capable of converting ultraviolet light into visible light are arranged side by side. The glass rod array (1), the ultraviolet light source (2) for irradiating the glass rod array (1) with ultraviolet light, and visible light emitted from each fluorescent glass rod (10) of the glass rod array (1) are received. A light receiving element array (3) provided with a light receiving element (30) for detecting the intensity of the light received from each light receiving element (30), and detecting the intensity of the glass rod array (1) and the ultraviolet light source (2). The position of the object (100) is detected based on the amount of change in the received light signal intensity that occurs when the object (100) passes through and blocks the ultraviolet light.

  More specifically, in the embodiment of FIG. 1, the fluorescent glass rod (10) is first formed into a long thin rod shape (also referred to as a fiber shape), which is excited by incident ultraviolet light and emits visible light. The glass rod array (1) is configured by arranging a plurality of each of the visible light emitting sides downwardly and densely in the horizontal direction. The fluorescent glass rods (10) may be juxtaposed without any gaps.

  The ultraviolet light source (2) can output ultraviolet light having a wavelength that excites the phosphor of the fluorescent glass rod (10). For example, an ultraviolet discharge lamp, an ultraviolet LED, and an ultraviolet laser can be considered. Various forms such as a point light source, a line light source, and a light source that emits parallel light are also possible. These ultraviolet light sources (2) are preferably arranged to irradiate ultraviolet light so that the entire glass rod array (1) is uniformly irradiated, that is, the amount of irradiation to each fluorescent glass rod (10) is substantially the same. If the uniformity cannot be achieved, the emission distribution may be measured and normalized in advance to correct the non-uniformity. Since the shadow of the object (100) needs to be projected onto the fluorescent glass rod (10) when the object (100) blocks the ultraviolet light, there is no shadow lamp even if it can emit ultraviolet light. A light source that does not have a difference in illuminance distribution due to shadows cannot be used.

  The light-receiving element (30) receives visible light and performs photoelectric conversion, and a plurality of light-receiving elements are aligned with the light-emitting side of the fluorescent glass rod (10), that is, the fluorescent glass rod ( The light-receiving element array (3) is configured in a one-dimensional arrangement side by side at a position where visible light emitted from 10) can be received. At this time, in this embodiment, the light receiving element (30) and the fluorescent glass rod (10) are arranged in a one-to-one relationship. Moreover, you may make it arrange | position one light receiving element (30) with respect to a some fluorescent glass rod (10) in the range which can satisfy the detection accuracy requested | required. As this light receiving element (30), for example, a solar cell or a photodiode can be considered.

  In the object position detecting device including the glass rod array (1), the ultraviolet light source (2), and the light receiving element array (3), the position of the object (100) is detected as follows.

  First, the ultraviolet light source (2) irradiates the glass rod array (1) with ultraviolet light in the absence of the object (100), and the received light signal intensity distribution of each light receiving element (30) (referred to as initial intensity distribution). ) Is measured in advance. More specifically, visible light is generated as fluorescence by ultraviolet light excitation in each fluorescent glass rod (10), and the visible light propagates through the rod and enters the light receiving surface of the light receiving element (30) from the end of the rod. To do. Since the fluorescent glass rod (10) has a higher refractive index than air, the generated visible light repeats internal reflection like an optical fiber and reaches the end of the rod. When the visible light is received by the light receiving element (30), electricity is generated by the photoelectric conversion effect, and therefore the photovoltage or photocurrent distribution is measured as the received light signal intensity distribution. This distribution is obtained by associating the position represented by the distance from the reference point (also referred to as the origin) of each light receiving element (30) and the light reception signal intensity of each light receiving element (30). The signal detection circuit (4) provided so as to be able to acquire the light reception signal from each light receiving element (30) is obtained. At this time, normalization of the initial intensity distribution may be performed as necessary.

  When the object (100) passes between the glass rod array (1) and the ultraviolet light source (2) after the above detection preparation is completed, more specifically, from the ultraviolet light source (2) to the glass rod array (1). When the object (100) passes across the ultraviolet light irradiation region, the ultraviolet light is blocked by the object (100), and therefore the ultraviolet light reaching the fluorescent glass rod (10) at the blocked position decreases. It goes without saying that the amount of decrease depends on the amount of ultraviolet light absorbed by the object (100).

  When the ultraviolet light is reduced, the visible light intensity generated by the fluorescent glass rod (10) is weakened, so that the received light signal intensity by each light receiving element (30) is also reduced, and thus when the object (100) passes. The position of the object (100) can be determined by obtaining the distribution of the reduction amount from the difference between the intensity distribution and the initial intensity distribution. That is, the position of the fluorescent glass rod (10) in which the received light signal intensity is reduced can be detected as the position of the object (100).

  Therefore, high-accuracy position detection at the level of several centimeters can be realized by setting the parallel density of the fluorescent glass rods (10) at intervals of several centimeters. At this time, by making each light receiving element (30) arranged with respect to each fluorescent glass rod (10) into a small photoelectric conversion element typified by a solar cell or a photodiode, the fluorescent glass rod (10) The arrangement corresponding to the interval of several centimeters is possible, and the amount of change in the received light signal intensity can be read with high accuracy and responsiveness. Of course, rather than increasing the number of fluorescent glass rods (10) and light receiving elements (30), high accuracy can be detected by increasing the density of parallel arrangement by narrowing the distance between them, so that excellent effect versus cost detection is possible. It can be a device.

[Second Embodiment]
FIG. 2 shows another embodiment of the object position detection apparatus of the invention of this application. In the embodiment of FIG. 2, a plurality of fluorescent glass rods (10) are two-dimensionally arranged in an orthogonal lattice pattern to constitute a glass rod array (1). More specifically, a glass rod array (1) in which fluorescent glass rods (10) extending in the vertical direction are arranged one-dimensionally in the horizontal direction and a fluorescent glass rod (10) extending in the horizontal direction are primary in the vertical direction. The original glass rod array (1) is arranged so as to be orthogonal to each other.

  As in the case of the one-dimensional arrangement, the light receiving element (30) is arranged so as to receive visible light from each in a one-to-one relationship with the fluorescent glass rod (10).

  Therefore, it can be said that two sets of the glass rod array (1) and the light receiving element array (3) are prepared and orthogonal to each other in the horizontal direction and the vertical direction.

  The signal detection circuit (4) is connected to each light receiving element (30), and can detect the light reception signal intensity distribution from each of the light receiving element arrays (3) in the horizontal direction and the vertical direction.

  Then, the two-dimensional position of the object (100) can be calculated by obtaining the two-dimensional distribution of the decrease amount of the received light signal intensity when the object (100) passes. In the present embodiment, a signal processing circuit (5) that performs this calculation process is provided, and the difference between the one-dimensional intensity distribution and the one-dimensional initial intensity distribution is obtained in each of the horizontal direction and the vertical direction, thereby reducing the one-dimensional distribution. And the positions x and y of the light receiving element (30) in the horizontal direction and the vertical direction where the light receiving signal intensity is reduced are determined based on the one-dimensional distribution of the reduction amount, and this is determined as the two-dimensional position of the object (100). Determine as x, y.

[Third Embodiment]
By the way, in the said 2nd Embodiment, although the fluorescent glass rod (10) is arrange | positioned two-dimensionally in the orthogonal | lattice grid | lattice form and the position of the object (100) is calculated from intensity distribution of 2 directions, more directions Can be used, the position of the object (100) can be calculated more accurately and with less error.

  Therefore, in the invention of this application, the glass rod array (1) and the fluorescent element array (3) may be arranged in two or more dimensions. For example, in FIG. 3, the glass rod array (1) and the light receiving element array ( Three sets of 3) are prepared and overlapped so that each faces three different angles. In each set, the fluorescent glass rod (10) and the light receiving element (30) have a one-to-one relationship.

  The signal detection circuit (4) is connected to each light receiving element (30), and can detect the light reception signal intensity distribution of the light receiving element array (3) in each direction.

  Then, by obtaining the distribution of the decrease amount of the received light signal intensity when the object (100) passes, the two-dimensional positions of the plurality of objects (100) can be calculated more accurately at one time. This calculation processing is performed by the signal processing circuit (5), for example, by applying a calculation method similar to that of CT scan, that is, by performing linear transformation of Radon transform and Radon inverse transform on the three-dimensional one-dimensional intensity distribution, The positions a, b, and c of the light receiving elements (30) in the respective directions where the light reception signal intensity is reduced are determined, and based on this, the two-dimensional position of each object (100) is determined more accurately. In other words, since the angle-dependent data of the object (100) can be acquired from three directions, more data necessary for the Radon transform and the Radon inverse transform can be obtained, and thus the accurate two-dimensional position of the object (100) can be obtained. Therefore, it is possible to calculate easily.

  In this case, it goes without saying that the three-dimensional shape of the object (100) can also be accurately determined.

[Position correction processing]
Here, in both the one-dimensional arrangement and the multi-dimensional arrangement, for example, as illustrated in FIG. 4, the ultraviolet light parallel to the plane P formed by the glass rod array (1) is normal to the plane P. When the light is irradiated vertically from N, or when the object (100) is a flat surface in close contact with the plane P of the glass rod array (1), the projection position of the object (100) is the ultraviolet light source (2). The projection plane of the object (100) is projected on the plane P directly below or directly below the object (100).

  However, for example, as illustrated in FIG. 5, when the ultraviolet light source (2) is a point light source, or when parallel light is irradiated obliquely, the projection is performed with the distance h between the object (100) and the plane P and the irradiation. It is projected at a position shifted according to the angle θ. That is, when the object (100) exists at a distance h from the plane P and the ultraviolet light source (2) is not directly above the object (100), the projection is performed depending on the irradiation direction of the light from the ultraviolet light source (2). The position will deviate from the back of or directly below the object (100).

  For example, it is assumed that the object (100) is located at a distance h from the plane P, the ultraviolet light from the ultraviolet light source (2) is parallel light, and is irradiated at an angle θ from the normal direction N of the plane P. Then, the shadow of the object (100) is projected at a position shifted by h · tan θ from the true position, and ultraviolet rays to the fluorescent glass rod (10) at the shifted position are reduced, so that positioning of h · tan θ is performed. An error will occur.

  Therefore, by correcting the measured projection position based on the type of light emitted from the ultraviolet light source (2) and the positional relationship between the plane P, the object (100), and the ultraviolet light source (2), it is more accurate. The position of the object (100) can be obtained. More specifically, for example, the distance h from the plane p of the object (100) and the angle θ with the ultraviolet light source (2) are measured to correct h · tan θ, or the distance h and the angle θ are corrected. Assuming one as a certain value, the other is calculated and h · tan θ is corrected, or the inverse of computer tomography (CT) is calculated from the position of the ultraviolet light source (2) and projection data of a plurality of measurement planes. What is necessary is just to calculate the multidimensional position of the object (100) by Radon transformation. In the embodiment of FIGS. 1 to 3, for example, this correction is performed by the signal processing circuit (5).

[Fourth Embodiment]
In the invention of this application, an object tracking device that accurately tracks the object (100) based on the position of the object (100) obtained by the object position detection device of the various embodiments described above can also be realized.

  FIG. 6 shows an embodiment of this object tracking device, and an object tracking configuration is added to the object position detection device in the case of a one-dimensional arrangement. In the present embodiment, first, a representative value of a decrease amount distribution of the received light signal intensity by the signal detection circuit (4) is calculated, then a deflection angle is calculated based on the representative value, and the optical changer driving circuit is calculated according to the deflection angle. The light deflecting device (7) is driven by (6) to deflect the tracking light from the tracking light source (8) to the position of the object (1). As a result, the object (100) can always be accurately tracked by the tracking light.

  For example, laser light can be used as the tracking light. In this case, the tracking light source (8) can be a laser light source, and the deflection device (7) can be an optical system such as a galvanometer mirror.

  The calculation of the representative value and the deflection angle may be performed by the signal processing circuit (5) (see FIGS. 1 to 3) or may be performed by providing a separate tracking calculation circuit (not shown). Good.

  Here, the tracking light deflection based on the representative value and the deflection angle will be further described taking the one-dimensional positioning in FIG. 1 as an example.

  First, assuming that the glass rod array (1) and the light receiving element array (3) are arranged in the x-axis direction, if the glass rod array (1) is uniformly irradiated by the ultraviolet light source (2), the light receiving element array (3) shows a uniform emission intensity distribution g (x) = c [c: constant value].

  If the object (100) is in close contact with the plane formed by the glass rod array (1), ultraviolet light from the ultraviolet light source (2) is shielded by the object (100), so g (x) Different emission intensity distributions f (x) are measured.

  This g (x) -f (x) means a difference in light intensity distribution that is shielded from light, and a representative value (maximum value, center of gravity position, or center value) of this distribution is the x coordinate of the center of the object (100). Will be shown.

Subsequently, to simplify the description, for example, as illustrated in FIG. 7, the optical deflection device (at the distance L on the normal line N ₁ from the plane P ₁ formed by the fluorescent glass rod (10) at the origin O of the x coordinate ( When there is a reflection surface R of the galvanometer mirror as 7), and there is a laser light source as a tracking light source (8) in a direction that forms an angle α with the normal N ₁ of the plane P ₁ from the reflection surface R, consider the determination of the angle β between the normal N ₁ of the normal N ₂ and the plane P ₁ of the reflecting surface R.

If the angle between the normal line N ₁ passing through the plane P _{1 of the} origin O, the galvanometer mirror, and the object (100) is γ, γ = tan (−1) (x / L). Since β−α = 180 ° − (β + γ) is obtained, β = (180 + α−γ) / 2, and the galvanometer mirror may be deflected in this direction.

[Fifth Embodiment]
In the invention of this application, it is possible to realize an information providing apparatus that not only tracks the object (100) but also can provide information to the object (100).

  More specifically, by using the tracking light as information light carrying information, the information light can always be accurately transmitted to the object (100) to provide information. The object (100) side may receive the information light and extract the information.

  Here, as illustrated in FIG. 8, the object (100) is moved between the one-dimensional glass rod array (1) and the ultraviolet light source (2) by the moving stage (110) of the fluorescent glass rod (10). The position detection and tracking of the object (100) when moved in the same direction as the juxtaposed direction will be described.

  The fluorescent glass rod (10) used is a functional fluorescent glass manufactured by Sumita Optical Glass Co., Ltd., which can convert weak ultraviolet light having a wavelength of 200 nm to 400 nm into red visible light with high efficiency, and the excitation light wavelength is 365 nm. Eight fluorescent glass rods (10) were laid out in a row to form a display-like glass rod array (1), and eight solar cell elements were installed at the lower end thereof as light receiving elements (30) at intervals of 2 cm. The ultraviolet light source (2) was disposed so as to irradiate the side surface of the glass rod array (1) with ultraviolet light. The signal detection device (4) detects the position of the object (100) from the amount of change in the photovoltaic voltage of the solar cell element.

  In this configuration, first, the change in visible light obtained from the lower end surface of the fluorescent glass rod (10) when the ultraviolet light intensity was changed was measured. FIG. 9 shows the measurement results. As can be seen from FIG. 9, when the ultraviolet light intensity is about 800 μW or more, visible light having an intensity of 1/200 is obtained in a substantially proportional relationship with the irradiated ultraviolet light intensity.

  Next, the uniformity sensitivity accuracy of each of the solar cell elements SC0 to SC7 was determined. A black paper having a width of 2 cm and a length of 10 cm is used for the object (100), and the moving stage (100) traverses between the glass rod array (1) and the ultraviolet light source (2) at a moving speed of 11.5 cm / s. To move. FIG. 10 shows the measurement results of the uniformity sensitivity accuracy at this time. Although there are individual differences among the solar cell elements SC0 to SC7, the photovoltaic voltage of the solar cell element where the object (100) has passed is It was confirmed that it was attenuated. From this, it can be seen that the position of the object (100) can be determined at the level of several centimeters.

  Then, based on the position information, the galvanometer mirror as the light deflecting device (7) is controlled, and the infrared laser light from the He-Ne laser as the tracking light source (8) is set at the position of the object (100). Deflection and tracking of the object (100). As the deflection angle, a negative light barycentric position as a distribution representative value is calculated, and the value of β calculated based on the negative optical barycentric position is used.

  FIG. 11 shows the tracking result at this time. As is clear from FIG. 11, the position of the object (100) and the deflection position of the infrared laser light are exactly the same, and the laser light also moves with the movement of the object (100). ) Is accurately tracked. In addition, the horizontal axis of FIG. 11 is a coordinate [cm], and this is expressed by the distance from the reference point of each light receiving element (30). In this embodiment, the leftmost end in FIG. The position of the light receiving element (30) is a reference point of 0 cm, and the distance between the light receiving elements (30) provided at intervals of 2 cm is 2 cm, 4 cm, 6 cm,.

  Of course, the invention of this application is not limited to the above embodiments, and various aspects are possible for details.

  As described above in detail, according to the invention of this application, an inexpensive object position detection device capable of detecting the position of an object with a high accuracy of several centimeters is provided, and the object can be accurately detected based on the detected position. There are also provided an object tracking device capable of tracking, and an information providing device capable of providing information to an object based on a detected position.

It is a figure for demonstrating one Embodiment of the object position detection apparatus of invention of this application. It is a figure for demonstrating another one Embodiment of the object position detection apparatus of invention of this application. It is a figure for demonstrating another one Embodiment of the object position detection apparatus of invention of this application. It is a figure for demonstrating the relationship between an object, an ultraviolet light source, and a glass rod array plane. It is a figure for demonstrating the positioning error of h * tan (theta) by the distance h from the glass rod array plane of an object, and angle (theta) from the object of an ultraviolet light source. It is a figure for demonstrating one Embodiment of the object tracking apparatus of invention of this application. It is a figure for demonstrating calculation of an optical gravity center position and a deflection angle. It is a figure for demonstrating the apparatus structure used for one Example of invention of this application. It is the graph which showed one measurement result of the visible light intensity of the fluorescent glass rod when changing ultraviolet light intensity. It is the graph which showed one measurement result of the uniformity sensitivity precision of a solar cell element. It is the graph which showed one measurement result of tracking accuracy when tracking an object with a laser beam.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass rod array 10 Fluorescent glass rod 2 Ultraviolet light source 3 Light receiving element array 30 Light receiving element 4 Signal detection apparatus 5 Signal processing apparatus 6 Optical deflection apparatus drive apparatus 7 Optical deflection apparatus 8 Tracking light source 100 Object 110 Moving stage

Claims (13)

A glass rod array in which fluorescent glass rods capable of converting ultraviolet light into visible light are arranged in parallel;
An ultraviolet light source that irradiates the glass rod array with ultraviolet light;
A light receiving element array in which a light receiving element that receives visible light emitted from each fluorescent glass rod of the glass rod array is disposed;
A reduction amount distribution is obtained from the difference between the light reception signal intensity distribution of each light receiving element generated when the object blocks the ultraviolet light and the initial light reception signal intensity distribution of each light receiving element measured in advance in the absence of the object. Based on this , the position of the fluorescent glass rod where the received light signal intensity is reduced is detected as the position of the object,
Distance of the object from the plane P of the glass rod array h, and the angle θ of the ultraviolet light with the normal direction N of the plane P of the glass rod array is measured, applying a correction of h · tan .theta the position of the object, it An object position detecting device characterized by the above.   2. The object position detection apparatus according to claim 1, wherein the light reception signal intensity distribution is obtained by relating the position represented by the distance from the reference point of each light receiving element and the light reception signal intensity of each light receiving element. 3. The object position detecting device according to claim 1, wherein the light receiving element is a solar cell or a photodiode. Object position detecting device according to any one of 3 claims 1, wherein the light-receiving signal intensity is photovoltaic voltage or photocurrent. Object position detecting device according to any one of claims 1 to 4, characterized in that the fluorescent glass rod is arranged one-dimensionally. And fluorescent glass rod is multidimensional arrangement, the object position detecting device according to any one of claims 1 and detects the multidimensional position of the object 4. The tracking light deflected to the position of the object detected by the object position detecting device according to any one of claims 1 to 6, object tracking apparatus, characterized in that tracking the object.   A representative value of the reduction amount distribution is calculated, a deflection angle is calculated based on the representative value, and the tracking light from the tracking light source is deflected to the position of the object by the optical deflector according to the deflection angle. The object tracking device according to claim 7.   9. The object tracking device according to claim 8, wherein the representative value of the decrease amount distribution is the maximum value, the center of gravity position, or the center value of the decrease amount distribution.   10. The object tracking device according to claim 8, wherein the light deflection device is a galvanometer mirror.   The plane P formed by the fluorescent glass rod at the origin O of the x coordinate ₁ Normal N from ₁ A reflection surface R of a galvanometer mirror as an optical deflecting device exists at an upper distance L, and a plane P is formed from the reflection surface R. ₁ Normal N ₁ And the plane P of the origin O when there is tracking light in a direction that makes an angle α with ₁ Normal N passing above ₁ If the angle between the galvanometer mirror and the object is γ, the normal N of the reflecting surface R ₂ And plane P ₁ Normal N ₁ The object tracking device according to claim 7, wherein the galvanometer mirror is deflected in a direction of an angle β = (180 + α−γ) / 2. Claims 1 to deflect the information light to the position of the object detected by the object position detecting device according to any one of 11, the information providing system for providing information to the object.   13. The information providing apparatus according to claim 12, wherein the tracking light is information light carrying information.