JP3214077B2 - Light source direction / position detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial applications] The present invention relates to a photoelectric conversion element, for example,
For example, the position sensing element (Position Sensing Device)
Below, simply referred to as "PSD")
A light-shielding device is provided between the surface and the light source.
To detect the intensity of light (light and dark) from the light source
Of the light source to specify the direction and / or position of the light sourcedirection
・ Position detection deviceIt is about.

[0002]

2. Description of the Related Art A conventional light source position detecting method and its apparatus will be described with reference to FIGS. As one application example, an "optical guiding apparatus for a moving object" is disclosed in Japanese Patent Laid-Open Publication No. Sho 61-5315.
This published prior art will be described again with reference to FIGS.

FIG. 12 is a schematic diagram showing a prior art unmanned vehicle optical guidance device, and FIG. 13 is a block diagram of the device of FIG. In this prior art, when a moving object R such as an unmanned vehicle is to travel correctly along a traveling route, as shown in FIG.
Detects the laser beam L irradiated from the PSD by the PSD installed on the moving body R, detects the deviation of the moving body R from the position of the laser spot incident on the light receiving surface of the PSD,
The steering mechanism of the moving body R is controlled based on the deviation.

Here, in the apparatus for detecting the position of the moving object R, as shown in FIG. 13, an output from the PSD 1 is input to an arithmetic processing circuit 3 via an amplifier 2, and the arithmetic processing circuit 3 The output is input to the motor 5 via the motor drive circuit 4 that drives the steering mechanism 6.

[0005]

In such a device,
The light incident on the light receiving surface of the PSD 1 must be in the form of a spot. Therefore, the laser beam L or light processed into a beam using a complicated optical system must be used as a light source. For this reason, there is a problem that the cost increases due to an increase in the light emitting source itself and its peripheral devices. An object of the present invention is to solve the above problems.

[0006]

Therefore, according to the present invention, for example, a light shielding device is provided between a light source and a light receiving surface of a PSD provided on a moving body, and the light source generated by the light shielding device is blocked by the light shielding device. By calculating the amount of deviation from the state of the surface distribution of the intensity of the incident light intensity, the incident angle of the incident light from the light source is detected, the direction and or position of the light source,
That is, a device for detecting the direction and / or position of the moving body is employed.

[0007]

Therefore, according to the present invention, the direction and / or position of the light source can be detected without the necessity of using a complicated lens system, a complicated mechanism, or the like for the incident angle of the light from the light source. Moreover, if a PSD having a wide light receiving surface is used and a light-shielding device that spreads in a plane is used, not only a plurality of incident angles in one direction but also a plurality of incident angles in another direction intersecting the one direction are detected. Therefore, the direction and position of the light source can be detected by one detection device.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a basic structure and a basic operation of a PSD which is one of direction and / or position detecting means which can be used in a direction / position detecting device for a light source according to the present invention are shown in FIGS. This will be described with reference to FIG. FIG. 1 shows the position detection of a light source according to the present invention.
P, one of the position detecting means that can be used for the device
FIG. 2 is a sectional view of a basic structure of the SD, and FIG. 2 is a schematic diagram for explaining a basic operation of the PSD shown in FIG.

As shown in FIG. 1, the PSD 10 has a P-type layer 11 on the surface of flat silicon, an N-type layer 12 on the back surface thereof, and an I-type layer 13 in the middle.
Incident light 2 such as a light spot
When 0 is incident, an electric charge proportional to the light energy is generated at the incident position. The generated charges pass through the P-type layer 11 as the photocurrent I ₀ and are output from the electrodes 14 and 15. Since the P-type layer 11 has a uniform resistance value over the entire surface, the photocurrent I ₀ is divided and output in inverse proportion to the distance to the electrodes 14 and 15.

[0010] Here, as shown in FIG.
L, the photocurrent I ₀ , the current output from each of the electrodes 14, 15, I ₁ , I ₂ , the distance from the end of the PSD 10 to the incident position, x, the longitudinal direction of the P-type layer 11. When the resistance value per unit length of the r, the current I ₁ and the current I _2, respectively equation (1), holds the expression (2) and Formula 3.

[0011]

(Equation 1)

[0012]

(Equation 2)

[0013]

(Equation 3)

When solving for the distance x from [Equation 3], [Equation 4] is obtained as follows.

[0015]

(Equation 4)

Since L is known from Equation 4, if the current I ₁ and the current I ₂ are detected, the incident position on the PSD 10 can be determined.

In the above description, the incident light 20 is a spot. Next, a case where the incident light 20 is incident not on the spot but on the surface will be considered with reference to FIG. FIG. 3 shows the PSD of FIG.
3A and 3B are schematic diagrams for explaining a basic operation when incident light is incident on a surface of the PSD, wherein FIG. A is a side view, FIG. B is a top view, and FIG. 3 is a graph showing the relationship between the position of the light and the light energy.

As shown in FIGS. 3A and 3B, when incident light enters the light receiving surface of the PSD 10 with a certain distribution by the light shielding device 40 which is one of the major features of the present invention, the intensity distribution, that is, A photocurrent is generated in proportion to the magnitude of the incident light energy. Now, as shown in FIG. 3C, this incident light energy E is a function of the position x of the PSD 10,
Assuming that it can be expressed as the following equation 5, the photocurrent i _ok generated at a certain point x _k (the width is assumed to be Δx = L / n) on the PSD 10 is expressed as the following equation 6. be able to.

[0019]

(Equation 5)

[0020]

(Equation 6) Here, α is a proportional constant when light energy is converted into a photocurrent.

Therefore, the currents I ₁ and I ₂ output from the electrodes 14 and 15 of the PSD 10 are expressed by the following equations (7) and (8).
And [Equation 9].

[0022]

(Equation 7)

[0023]

(Equation 8)

[0024]

(Equation 9)

Next, as shown in FIG. 4, a certain distribution (E
= F (x)), consider an equivalent spot-shaped incident light having the same effect as light incident on the PSD 10 in a planar manner. That is,
The output currents I ₁ and I ₂ from the electrodes 14 and 15 of the PSD ₁₀
Is spot-like incident light that is completely equal to the planar incident light. When the incident position of the PSD10 edge of the spot-shaped incident light and x _G, holds the following [Equation 10] to [Expression 3] and [Expression 9].

[0026]

(Equation 10)

Here,

[Equation 11] It is.

As can be seen from FIG. 3A, the incident angle Θ of the light source 30 corresponds to the light distribution E = f (x) on the PSD 10. That is, by observing the currents I ₁ and I ₂ using [Equation 11], the position x of the equivalent spot-like incident light is obtained.
_G understand the incident angle Θ of the light source 30 from the x _G can be known.
However, x _G satisfies [Equation 10], and the following [Equation 12] exists between Θ and x _G.

[0029]

(Equation 12)

By substituting this [Equation 12] for [Equation 11], the following [Equation 13] in which Θ is represented by I ₁ and I ₂ is obtained. It can be seen from this equation that if I ₁ and I ₂ are known, the incident angle Θ can be determined.

[0031]

(Equation 13)

As described above, even if the light source 30 is not a beam like a laser but a light that spreads radially, the PSD
By installing the light shielding device 40 on the surface of the light receiving surface of No. 10, light B and dark D of light as shown in FIGS. 3B and 3C.
And the incident angle of the light source 30 can be detected from the current value based on the light energy corresponding to the area ratio and the distribution state. Therefore, an optical system or the like for processing the light source 30 into a beam is not required, and sunlight or the like can be used as the light source 30.

Next, a specific configuration of the present invention is shown in FIGS. First, a light shielding device 40 constituted by a light shielding plate
FIGS. 5 to 7 show a light source direction and / or position detection device (hereinafter simply referred to as a “detection device”). The detection device Da according to the first embodiment shown in FIG.
The light-shielding device 40A is configured such that the cells formed by the light-shielding plates are arranged in a line on the light-receiving surface 10A. This embodiment has a structure following the principle diagram shown in FIG. In this embodiment, PSD1
0A is a large area PS manufactured by Hamamatsu Photonics Co., Ltd.
D series S1352 was used.

The second embodiment shown in FIG. 6 is a detection device Db obtained by developing the first embodiment of FIG.
The light-shielding device 40B is configured such that the cells are arranged in a matrix on the light-receiving surface 10B of b. This embodiment further extends the light receiving surface from the first embodiment, and not only a plurality of incident angles in a row in one direction but also a row in another direction crossing the row in one direction, that is, in this embodiment, Since a plurality of incident angles in a row can also be detected, the direction and position of the light source can be detected by one detection device. Therefore, there is a feature that the position of the light source can be detected more accurately and with high sensitivity. The PSD 10b used in this example is a large-area PSD series S1869 or S1869 manufactured by Hamamatsu Photonics KK
Model 1881 was used.

The detection device Dc according to the third embodiment shown in FIG. 7 is also S1869 manufactured by Hamamatsu Photonics KK
A light-shielding device 40C having a shape in which light-shielding plates are formed in large and small circles on the light-receiving surface 10C of the PSD 10c using a mold or an S1881 type PSD, and these circular light-shielding plates are arranged concentrically at equal intervals. It was constructed in the structure. In this embodiment, similarly to the second embodiment, the light receiving surface can be expanded to detect not only a plurality of incident angles in one direction but also a plurality of incident angles in another direction crossing the one direction. , The direction and position of the light source can be detected by one detection device.

The detection device Dd according to the fourth embodiment shown in FIG. 8 has a bar-shaped light-shielding device 40D set up at the center on the light receiving surface 10D of the PSD 10d, and the shadow by the light source, that is,
The dark portion D is configured to drop on the light receiving surface 10D. In the figure, one rod is set, but if a plurality of rods are set, the detection accuracy of the incident angle of light can be improved. In FIG. 6B, the symbol R indicates the length of the shadow D.

The detector 5 according to the fifth embodiment shown in FIG. 9 comprises a transparent substrate 5 made of glass or the like parallel to the light receiving surface 10E of the PSD 10e and with a predetermined interval above the light receiving surface 10E.
0, a light-shielding device 40E having an opaque mark at its center.
Are arranged and configured. Therefore, it is configured such that the shadow of the light source, that is, the dark portion D is dropped in a spot shape on the light receiving surface 10D. In this embodiment, the opaque mark is provided at one position. However, when a plurality of opaque marks are provided at other different positions, the accuracy of the light incident angle can be improved. In FIG. 6B, the symbol R indicates the distance from the opaque mark of the light shielding device 40E to the shadow D.

FIG. 10 shows a detector Df according to a sixth embodiment. The detecting device Df of this embodiment is the fifth device.
Is a opaque cross-shaped object at a predetermined interval above and parallel to the light receiving surface 10F of the PSD 10f, and the center of the intersection is the light receiving surface 10E.
A light-shielding device 40E configured to be located at the center of the light-emitting device is disposed. Therefore, the shadow by the light source, that is, the dark portion D is projected on the light receiving surface 10E in a cross shape. Depending on the position of the light source, the position of the shadow D, that is, the length from the intersection center of the cross-shaped object changes, and therefore, the position of the light source can be detected. Although only one set of cross-shaped objects is used in this embodiment, for example, a light-shielding device for a double cross-shaped object in which another set of cross-shaped objects is arranged with the position of the center of the intersection shifted is used. Thus, the detection accuracy of the incident angle of light can be improved. In FIG. B, reference symbol R indicates the distance from the center of the intersection of the light shielding device 40F to the projection D.

In the embodiments shown in FIGS. 8 to 10, the direction of the light source is determined, but the distance of the light source 30 is not determined.
As shown in FIG. 11, for example, a plurality of, for example, two detection devices Dd1 and Dd shown in FIG.
By arranging the light sources 2 at a certain distance and determining the directions Θa and Θb of the light source 30 based on [Equation 13], the position of the light source 30 can be detected in a triangulation manner.

5 to 7, the direction and the distance of the light source 30 can be measured. However, in order to further improve the accuracy, a plurality of these detecting devices are used as described above.
It is more effective to use them by arranging them at different positions.

Any one of these detecting devices of the present invention
For example, if it is attached to a moving object as described in the section of [Prior Art], the direction and / or position of the light source is detected, and based on the direction and / or position of the light source, the moving object is detected. The direction and / or position can be controlled. Further, for example, if the detection device of the present invention is attached to the security light, the security light can be turned on / off according to the sunrise and sunset of the sun and / or according to the irradiation angle. Furthermore, if the detection device of the present invention is attached to a panel of a solar cell, the panel can follow the movement of the sun up and down, and efficient power generation can be performed. Furthermore, when the spacecraft is docked, a light source is attached to a predetermined location of one of the spacecrafts to be docked, and one or a plurality of the detection devices of the present invention are mounted at a predetermined location of the other spacecraft to be docked. By attaching them individually, both spacecrafts can be reliably docked. Thus, the light source direction / position detecting device of the present invention can be applied to a wide range of technical fields.

[0042]

As described above, according to the present invention, since radial light is used as a light source, there is no need to prepare a beam light processed using a laser or an optical system. Compared to these light sources, the entire system can be made cheaper.

Also, since the light shielding device provided on the light receiving surface of the light receiving device does not require a complicated mechanism such as a movable portion, the reliability is high, the size of the detection device can be reduced, and the device can be manufactured at low cost. .

In addition, there are a number of excellent effects, such as that a moving body provided with a light source or a moving body provided with a detecting device can be correctly run along a running path.

[Brief description of the drawings]

FIG. 1 is a diagram showing a direction and / or position detecting means P which can be used in a direction / position detecting device for a light source according to the present invention;
It is sectional drawing which showed the basic structure of SD.

FIG. 2 is a schematic diagram for explaining a basic operation of the PSD in FIG. 1;

FIG. 3 is a schematic diagram for explaining a basic operation when incident light is incident on the surface of the PSD in FIG. 1;
Is a side view, FIG. B is a top view, and FIG. C is a graph showing the relationship between the position on the light receiving surface of the PSD and the light energy.

FIG. 4 is a graph of light energy incident on a location on the surface of the PSD.

FIG. 5 is a perspective view of a light source direction and / or position detecting device according to the first embodiment of the present invention.

FIG. 6 is a perspective view of a light source direction and / or position detecting device according to a second embodiment of the present invention.

FIG. 7 is a perspective view of a light source direction and / or position detecting device according to a third embodiment of the present invention.

FIGS. 8A and 8B are perspective views and FIG. 8B is a top view of a light source direction detecting device according to a fourth embodiment of the present invention.

9A and 9B are perspective views and FIG. 9B is a top view of a light source direction detecting device according to a fifth embodiment of the present invention.

FIG. 10 is a perspective view and FIG. 10B is a top view of a device for detecting the direction and / or position of a light source according to a sixth embodiment of the present invention.

FIG. 11 is a schematic diagram for explaining a method for detecting the direction and position of a light source using the fourth embodiment of the light source direction detection device of the present invention shown in FIG.

FIG. 12 is a schematic diagram illustrating a conventional optical guidance device for an unmanned vehicle.

FIG. 13 is a block diagram of the device of FIG.

[Explanation of symbols]

 Da light source direction and position detection device Db light source direction and position detection device Dc light source direction and position detection device Dd light source direction detection device De light source direction detection device Df light source direction detection device D dark (shadow) の light source Incident angle 10a PSD 10b PSD 10c PSD 10d PSD 10e PSD 10f PSD 10A Light receiving surface of PSD 10a 10B Light receiving surface of PSD 10b Light receiving surface of PSD 10c 10D Light receiving surface of PSD 10d 10E Light receiving surface of PSD 10e Light receiving surface of 10F PSD 10f Light source 30 Light source And light-shielding device 40B for the position detection device Da 40B light-shielding device 40C for the direction and position of the light source Dc Light-shielding device 40D for the direction and position of the light-source detection device DC Detector De light-shielding device 40F light source direction and the position detecting device Df for the shading device

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01B 11/00-11/30 102 G01C 1/00-1/14

Claims (5)

(57) [Claims] The shading device between 1. A light source and the light-receiving surface of the photoelectric conversion device provided, resulting is blocked by the shading device, before
Detects the state of surface distribution depending on the intensity of incident light from the light source
In the apparatus for detecting the direction and position of a light source for
The optical device is formed in a grid-like structure.
Light source direction / position detection device. The shading device between 2. A light source and the light-receiving surface of the photoelectric conversion device provided, resulting is blocked by the shading device, before
Detects the state of surface distribution depending on the intensity of incident light from the light source
In the apparatus for detecting the direction and position of a light source for
Concentric circles of multiple annular plates with different diameters at equal intervals
Characterized by being formed in a structure arranged in a matrix
Direction and position detection device. (3) Shield between the light source and the light receiving surface of the photoelectric conversion device
An optical device is provided, and the
Detects the state of surface distribution depending on the intensity of incident light from the light source
In the apparatus for detecting the direction and position of a light source for
The optical device has a rod shape, and the plurality of light shielding devices are
Placed upright on the light-receiving surface of the converter at a specified interval
Light source direction / position detection device
Place. (4) Shield between the light source and the light receiving surface of the photoelectric conversion device
An optical device is provided, and the
Detects the state of surface distribution depending on the intensity of incident light from the light source
In the apparatus for detecting the direction and position of a light source for
An optical device is spaced a predetermined distance from the light receiving surface of the photoelectric conversion device.
In the center of the transparent substrate
Marks are provided at predetermined intervals.
Light source direction / position detector. 5. A shield between a light source and a light receiving surface of a photoelectric conversion device.
An optical device is provided, and the
Detects the state of surface distribution depending on the intensity of incident light from the light source
In the apparatus for detecting the direction and position of a light source for
The optical device is a cross-shaped object, and a plurality of the light shielding devices are provided.
Each of the cross portions of the light shielding device is provided with the photoelectric conversion device.
A predetermined distance to the upper center of the light receiving surface
Light source direction and position
Output device.