JPS6355406A - Detecting device for incident position of light spot or the like - Google Patents

Abstract

PURPOSE:To detect an incident position of a light spot, etc., by a simpler constitution, by deriving a ratio of output of end parts of two thin wire members. CONSTITUTION:When a light spot S is made incident on the surface of a plate body 1, a fluorescent agent in the plate body 1 is excited by the light spot S and a fluorescence is generated in a random direction, and this fluorescence is propagated through the inside of the plate body 1 and reaches each end face 1a-1d. In this case, the light intensity of each end face 1a-1d increases or decreases in accordance with a distance to the light spot S. Subsequently, emitted fluorescences from the end faces 1a-1d are made incident on this wire members 2a-2d, respectively, and emitted in a random direction again by the fluorescent agent contained in the members 2a-2d, propagated through the inside of the members 2a-2d, and made incident on photoelectric transducers 3a, 3a'-3d' which have been placed at both its end parts. Accordingly, by deriving a ratio of the sum of outputs of the photoelectric transducers 3a, 3a', and the sum of outputs of the photoelectric transducers 3c, 3c', a position of the light spot S in the X direction can be derived.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an incident position detection device for a light spot, etc., for detecting the incident position of a light spot or radiation.

[Prior Art] Conventionally, image pickup tubes and COD (charge-coupled devices) have been known as two-dimensional detection devices for detecting the incident position of a light spot, etc., but both are expensive and require processing circuits. It's complicated.

The present applicant has already stated in Japanese Patent Application No. 60-274499,
We have proposed a device that detects the incident position of a plate containing a secondary light emitter, but in this case one-dimensional or multiple photoelectric conversion elements are required.

[Object of the Invention] An object of the present invention is to provide an incident position detection device for a light spot, etc., which can detect the incident position of a light spot, etc., with a simpler configuration.

[Summary of the Invention] The gist of the present invention for achieving the above-mentioned object is to provide a secondary light emitting material or a scattering material by closely contacting the end face of a transparent or translucent plate containing a secondary light emitting material or a scattering material. A transparent or translucent strip member containing a scattering material is arranged, a photoelectric conversion element is arranged at at least one end of the strip member, and a light spot or radiation is incident on the surface of the plate, The secondary light or scattered light generated within the plate is guided to the strip member to generate two-dimensional or scattered light again, and the incident position of the light spot or radiation is determined from the light intensity obtained by the photoelectric conversion element. This is a device for detecting an incident position of a light spot or the like.

[Embodiments of the invention] The present invention will be explained in detail based on illustrated embodiments.

In FIG. 1, 1 is a transparent or translucent plate made of, for example, synthetic resin and containing a fluorescent agent.

Each end surface 1a-1d of this plate l is provided with a strip member 2a made of transparent or translucent synthetic resin and containing a fluorescent agent in the same way.
~2d are in close contact. And these strip members 2
At the ends of a to 2d, photoelectric conversion elements 3a, 3a', 3b, 3b', . . . , 3d made of, for example, solar cells etc.
The outputs of these photoelectric conversion elements 3a, 3P1', 3b, 3b', φ, 3d'' are input to an arithmetic processing circuit (not shown).

Here, when the light spot S is incident on the surface of the plate 1, the fluorescent agent in the plate 1 is excited by the light spot S and emits fluorescence in a random direction, and this fluorescence propagates through the plate 1. and reaches each end face 1a-1d. In this case, the fluorescence is attenuated while propagating through the plate 1, and the light intensity at each position of each end face 1a to 1d monotonically increases or decreases depending on the distance to the optical board S. The fluorescence emitted from the end faces 1a to 1d enters the strip members 2a to 2d, respectively, and is emitted again in a random direction by the fluorescent agent contained in the strip members 2a to 2d. and photoelectric conversion elements 3a, 3a arranged at both ends thereof.
', 6..., 3d''.

In this case, the fluorescent agent absorbs light in a wavelength band centered on, for example, about 500 nm and emits light in a wavelength band centered on about 600 nm. It is desirable that the fluorescent agents in the strip members 2a to 2d absorb light; therefore, the fluorescent agents contained in the plate l and the fluorescent agents contained in the strip members 2a to 2d are of different types. It is preferable that

In order to determine the position of the light spot S in the X direction in FIG. By determining the ratio of the sum of the outputs of the photoelectric conversion elements 3C and 3c'', the position of the light spot S on the surface of the plate 1 in the X direction can be determined regardless of the amount of incident light.

That is, the length of the side of the plate 1 is D, and the distance from the light spot S to the end surface 1 is
Letting the shortest distance to a be X, the photoelectric conversion elements (3a, 3a'), (3c, 3c'
) The output Pa and Pc due to the light intensity of the fluorescence obtained in difference,
It is a constant that depends on the light conversion efficiency of the fluorescent agent and the fluorescence attenuation rate in the plate 1 and the strip member 2. At this time, both photoelectric conversion elements (
Sum of outputs Pa+P of 3a, 3a゛), (3c, 30')
If we calculate c and the difference Pa-Pc, and divide the difference Pa-Pc by the sum Pa+Pc, then f(x)=Pc@D
/ (Pa+Pc), and since the characteristics of f(x) can be determined in advance, it is possible to determine the distance X without depending on the light intensity of the light spot S, etc.

Note that the output characteristics from the end surface of the plate 1 in this case are as follows:
As shown in Figure (a), the closer the light spot s is located to the center of the plate 1, the greater the output tends to be. On the other hand, the fluorescence incident on the strip member 2 with the same amount of light is transferred to the photoelectric conversion elements 3 at both ends.
When the light is detected and the sum is calculated, the amount of light incident on the central portion becomes smaller due to the attenuation of the amount of light, as shown in FIG. 2(b). Therefore, in the end, both curves cancel each other out, and the output obtained from the photoelectric conversion elements 3 at both ends becomes 2r! As shown in 4(C), it becomes almost flat.

Furthermore, in the Y direction, the position of the light spot S can be similarly determined from the output of the photoelectric conversion elements (3b, 3b', 3d, 3d') provided on the end faces of the two strip members 2b and 2d, and It is possible to detect the two-dimensional position of the light spot S in addition to the direction.

In FIG. 1, the position of the light spot S on the plate 1 is projected onto the strip members 2a and 2C, and the photoelectric conversion elements 3a and 3a are
The position of the optical switch S in the Y direction can also be determined from the ratio of the outputs of the photoelectric conversion elements 3C and 3c' or the output ratio of the photoelectric conversion elements 3C and 3c'.

As mentioned above, the wavelength of the excited fluorescence differs depending on the wavelength of the incident light on the optical subwoofer S or the type of fluorescent material, but each filter is equipped with a filter that transmits only the excitation light of the fluorescent material contained in the strip member 2. Photoelectric conversion elements 3a, 3a',..., 3d
If it is installed in front of ', it is possible to ignore the influence of noise and perform accurate measurements. Of course, it is desirable to expose only the surface of the plate l and block the rest from external light.
If a complete dark box cannot be formed, the incident light of the optical spot S is modulated and the photoelectric conversion element 3a is synchronized with this modulated light.
, 3a', 3b, 3b', . . . , 3d' may be detected to remove the influence of external light.

Further, in FIG. 3, two orthogonal end surfaces 1 of the plate 1 are shown.
Strip members 2a and 2b are arranged only on a and 1b, respectively, and photoelectric conversion elements 3a, 3a', and
The position of the light spot S is determined from 3b and 3b'. Further, although the photoelectric conversion elements 3 are provided at both ends of the strip member 2, measurements can be made even if the photoelectric conversion elements 3 are provided at only one end if the characteristics of the incident light are known.

Further, the plate l may not be a flat surface as in the embodiment, but may have a curved surface, and can be appropriately used depending on the purpose of use, such as a spherical surface or a cylindrical shape. Furthermore, since the incident intensity can be reduced by roughening the surface of the plate l, it is possible to give a roughness distribution to the surface and to make the characteristics shown in FIG. 2 more linear.

Furthermore, the object to be measured is not necessarily a light spot, and a light spot can also be obtained in the plate 1 by point-like incidence of radiation. In this case, it is preferable to have scintillators scattered within the plate 1. In addition to the fluorescent agent and the scintillator, the material mixed into the plate 1 may also be aluminum powder, although the light intensity will be small. A light diffusing material such as may be mixed.

Note that this incident position detecting device for light spots etc. is generally used as a measuring device, but it can also be used as a digitizer input device for a computer or the like. Furthermore, even if a single figure is input, it can be sufficiently recognized if the light spot is moved in time series.

[Effects of the Invention] As explained above, the device for detecting the incident position of a light spot, etc. according to the present invention has an extremely simple configuration and can determine the position of a light spot or radiation, which is not possible with conventional devices due to the cost. A large-sized detection device can also be manufactured at low cost.

[Brief explanation of drawings]

The drawings show an embodiment of the device for detecting the incident position of a light spot, etc. according to the present invention; FIG. 1 is a perspective view thereof, FIG. 2(a) is an output characteristic diagram of a plate, and FIG. Output characteristic diagram, (C
) is an overall output characteristic diagram, and FIG. 3 is a perspective view of another embodiment. Reference numeral 1 represents a plate, 1a-1d end faces, 2a-2d strip members, and 3a-3d' photoelectric conversion elements.

Claims (1)

[Claims] 1. A transparent or semi-transparent thin plate that also contains a secondary light emitter or a scattering material, in close contact with the end face of a transparent or semitransparent plate containing a secondary light emitter or a scattering material. A strip member is arranged, a photoelectric conversion element is arranged at at least one end of the strip member, and a light spot or radiation is made incident on the surface of the plate, and secondary light or scattering is generated within the plate. A light spot, etc., characterized in that the light is guided to the strip member to generate two-dimensional or scattered light again, and the incident position of the light spot or radiation is detected from the light intensity obtained by the photoelectric conversion element. Incident position detection device. 2. Claim 1 in which the secondary light emitter is a fluorescent agent
A device for detecting the incident position of a light spot, etc., as described in 2. 3. The strip members are arranged on opposite end faces of the plate, and from the ratio of the output of the photoelectric conversion elements arranged on these strip members, the incidence in the direction perpendicular to the longitudinal direction of the strip members is determined. An incident position detection device for a light spot or the like according to claim 1, which detects a position. 4. Arrange the photoelectric conversion elements at both ends of the strip member, project the incident position of the plate onto the strip member from the ratio of the outputs of both photoelectric conversion elements, and determine the longitudinal direction of the strip member. An incident position detecting device for a light spot or the like according to claim 1, which detects an incident position of a light spot.