JPS61186813A - Range finder - Google Patents

Abstract

PURPOSE:To measure distance in two dimensions with simple constitution by performing arithmetic by using an output obtained by turning on light emitting elements on time-series basis. CONSTITUTION:Light emitted from a point at distance Dy from the center of a light emitting element 1 reaches a body P through a projection lens 3 and part of reflected light from the body P passes through a photodetection lens 4 to form an image at a point which is Sy away from the center of the photodetecting element 2. At this time, a reference length (d) and focal lengths f1 and f2 of the lenses 3 and 4 are constants which are already known and positions X0 and Y0 of the body can be calculated from equations I and II when the position Dy of the light emission point and position Sy of the photodetection point are measured. for the purpose, the position Dy of the light emission point is varied by using a proper means to calculate the position of the body P on an X-Y plane. Namely, the element 1 is turned on successively to measure not only the distance to one point P on the body, but also distances to many bodies.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a two-dimensional distance measurement device.

BACKGROUND OF THE INVENTION As shown in FIG. 4, the distance to an object P is generally determined based on the principle of triangulation. That is, in FIG. 4, light emitted from the light emitting element 11 passes through the projection lens 12 and hits the object P. The light reflected from the object P passes through the light receiving lens 13 and forms an image on the light receiving element 14. As the light receiving element 14, an element such as an image sensor, a position sensing stable device (P, S, D), G, C0D, etc. is used. The position of such an image on the light receiving element 14 and the baseline length interval d between the light emitting element 11 and the light receiving element 14
Once this is known, the distance to the object P can be determined from the geometric relationship.

Problems to be Solved by the Invention In the distance measuring system as shown in FIG. 3, only the distance L to the object P, that is, one-dimensional distance information, can be obtained.

The present invention has been made in view of these points, and an object of the present invention is to provide an analytical system that can obtain two-dimensional distance information with a simple configuration.

Means for Solving the Problems In order to solve the above problems, the present invention uses a light emitting element that does not emit light at just one point, but emit light sequentially at a certain set timing (for example, an LED array). The structure is such that the positions of the light emitting point of the light emitting element and the light receiving point of the light receiving element are known.

Function: With the above-described configuration, the present invention provides information on which light-emitting element among the light-emitting elements arranged in the - column emitted light, and information on which point on the light-receiving element the light was reflected by the object P and received. By measuring information, the object P
This allows the position of the object to be measured in two dimensions.

Embodiment FIG. 1 shows a diagram of the principle of the present invention. The principle of the present invention will be explained using FIG.

In Figure 1, 1 is a light emitting element arranged in a row, X, Y.
It shall be placed at the origin of the coordinates. Further, the light emitting element 1 is arranged at a focal length f1 of the projection lens 3. In addition, the light receiving element 2 is
It is arranged at a position apart in the axial direction and parallel to the light emitting element 1. Further, the light receiving element 2 is arranged at a position of the focal length f2 of the light receiving lens 4. The object is represented by P and its coordinates are P(xo, Yo).

In the above configuration, light emitted from a point Dy apart from the center of the light emitting element 1 passes through the projection lens 3 and reaches the object P. It is assumed that the object P diffusely reflects the light, and a part of the reflected light passes through the light-receiving lens 4 and forms an image at a point separated by Sy from the center of the light-receiving element 2.

In this case, the following two equations hold true from the geometrical relationships.

From (1) and (2), from equations (3) and (4), the baseline length d, the focal length f1 of the projection lens 3 and the light receiving lens 4. f2 is a known constant, and if the number of positions of the light emitting points and the position S7 of the light receiving points can be measured, the position xO+xO of the object P can be determined.

Therefore, by changing the position Dy of the light emitting point using appropriate means, the position of the object P on the X, Y plane can be determined. This situation is shown in FIG.

In FIG. 2, the same parts as in FIG. 1 are indicated by the same symbols. D3 from the center of the light emitting element 1 with respect to the object P and another object
．． If it is assumed that the light from a point distant by ' is reflected, and if the light is received at a point q from the center of the light receiving element 2, then in equations (3) and (4), Dy-=Dy', Sy-S
By substituting the value of y', the coordinates of the object P' are xo/, Yo
' is found.

By successively changing the distance Dy of the light emitting point of the light receiving element 10 in this way, the position of the object P corresponding to each can be determined.

FIG. 3 shows an embodiment using the principle of the present invention.

In FIG. 3, the same parts as in FIG. 1 are indicated by the same symbols. In FIG. 3, the light emitting elements 1 may be elements arranged in a line, such as an LED array or a laser array. Further, the wavelength of the light emitting element 10 is preferably a wavelength of near infrared rays or infrared rays in order to reduce the influence of background light. As the light receiving element 2, a solid-state image sensor, an image scanner, a position sensor (P, S, D), etc. can be considered. Third
In the figure, 5 is an A/D conversion circuit for sending the output from the light receiving element 2 to the microprocessor, and 6 is the XY of the object P.
A display device 8 for displaying coordinates is a scanner and a drive circuit for sequentially causing the light emitting elements 1 to emit light according to instructions from the microprocessor sensor 7. The operation of the embodiment shown in FIG. 3 will be briefly explained.

In response to instructions from the microprocessor 7, points away from the center of the light emitting element 1 emit light. The light is reflected by the object P and received at a point ~ away from the center of the light receiving element 2. The microprocessor 7fd uses the measured values of Dy and sy (3
), calculated from equation (4), the XY coordinates of the object P xo, Y
o is displayed on the display device 6.

Effects of the Invention According to the present invention, by sequentially causing the light emitting elements 1 to emit light, it is possible to measure not only the distance to one point P of an object but also the distances to many objects. Furthermore, since the light emitting element 1 is scanned electronically, measurement can be performed at high speed, and the entire device can be made smaller and lighter.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram of a distance measuring device according to an embodiment of the present invention, and FIG.
The drawings are principle diagrams supplementing the present invention, FIG. 3 is a block diagram of an embodiment of the present invention, and FIG. 4 is a block diagram of a conventional device. 1... Light emitting element, 2... Light receiving element, 3
...Projection lens, 4...Receiving lens, 5
...VD conversion circuit, 6 ...Display device, 7
...Microprocessor, 8...Scanner and drive circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person1,
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Claims (1)

[Claims] A light emitting means and a light receiving means are provided at a predetermined baseline interval,
The light-emitting means includes light-emitting elements arranged in a series parallel to the base line, and the light-receiving means includes a light-receiving element whose light-receiving position can be detected, and the light-emitting elements sequentially emit light in a time series. A distance measuring device characterized by detecting an object distance by calculating using time-series output.