JPS61246606A - Measuring method for size of object - Google Patents

Abstract

PURPOSE:To enable simple and highly accurate measurement irrespective the size of an object of measurement, by irradiating the measured end portions of the object by two parallel beams of light being reverse in the direction to each other. CONSTITUTION:Parallel beams 10 of light are applied to an object 9 of measurement from the directions reverse to each other so that the respective parts of the parallel beams 10 are intercepted by the measured end portions 9a of the object 9. The areas W2 of the parallel beams 10 intercepted by the object 9 (or the areas thereof not intercepted by the object) are detected to measure the size of the object 9 of measurement. According to this method, the same detecting means (photosensors) 1 can be used irrespective of the size of the object 9 of measurement, and the object 9 can be measured constantly with the same accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of measuring the dimensions of an object in a non-contact manner using an optical sensor.

(Prior Art) Conventionally, as one method of optically measuring the dimensions of an object, a parallel beam of light is irradiated from an illumination device onto the object to be measured, and the portion of the parallel beam that is blocked by the object to be measured ( A device is known in which the dimensions of an object to be measured are measured by detecting the unobstructed portion) using a detection means such as an optical sensor.

FIGS. 2 and 3 are diagrams showing typical examples. In the method shown in FIG. 2, an optical sensor (21) is provided to face the illumination device (20), and the entire shape (23) of the object to be measured (22) placed between the optical sensors (21) and 21 is measured by the optical sensor (23). 2
By detecting in step 1), the dimensions (
It is intended to measure the outer diameter, etc.). On the other hand, the method shown in FIG. 3 uses two lighting devices (24) and (2
4) and optical sensors j (25), (25) are arranged in parallel facing each other, and from the illumination devices (24), (24) to both ends (28a), (28a) of the object to be measured (2B).
), parallel rays (27) and (27) are irradiated in the same direction, and among these parallel rays (27) and (27), the parallel rays that are not blocked by the object to be measured (2B)! 1 (28)
, (28) are received by optical sensors (25) and (25),
The purpose is to measure the dimensions of the object to be measured (26) from the output (detection) signals of these optical sensors and known values (the distance between the two optical sensors (25), (25), etc.).

(Problem to be Solved by the Invention) However, in the conventional measurement method described above, in the former case, it is impossible to measure if the object to be measured protrudes from the parallel light beam. In order to measure this, it is necessary to widen the irradiation area of parallel light beams and increase the number of optical sensor elements accordingly, which leads to an increase in the size of the optical sensor and the condensing lens, which increases cost.

Furthermore, as the number of optical sensor elements increases, the number of times of sampling, number of calculations, etc. increases, and as a result, the measurement time becomes longer.

On the other hand, in the latter case, the width between the optical sensors (25), (25), specifically the size of the object smaller than the distance between the light receiving parts (25a), (25a) of the optical sensors (25), (25) cannot be measured.

Therefore, the present invention has been made to improve the above-mentioned conventional problems, and its purpose is to provide a measurement method that can easily and accurately measure the dimensions of an object, regardless of its size. We are here to provide you with a method.

(Means and operations for solving the problems) In order to solve the above problems, the present invention provides parallel light beams (10) and (1G) to the object to be measured (9) from opposite directions. 10), (10) are irradiated so that some of them are blocked by the measurement ends (9a), (9a) of the object to be measured (9), and among the parallel rays (1G), (10), the object to be measured is (8) By detecting the area (w2) (or unobstructed area) of the object to be measured (8),
), the object to be measured (8)
The same detection means (1), (
1) can be used, and the object to be measured (8) can always be measured with the same precision (
resolution).

(Example) Embodiments of the present invention will be described below with reference to FIG.

FIG. 1 is a schematic diagram illustrating an embodiment of the present invention in the case of measuring the outer diameter dimension of a rod-shaped member.

The optical sensors indicated by symbols (1) and (1) are condensing lenses (2)
.

(2) and a transducer (4), (4) that converts the optical signal into an electrical signal such as a charge.
It consists of transducer sections (5), (5) equipped with.

On the other hand, the lighting devices indicated by symbols (8) and (G) are light sources (7),
(7), and projecting lenses (8) and (8) for irradiating the light from the light sources (7) and (7) as parallel rays, and these two optical sensors (1), (1) and the illumination devices (8), (8) are configured such that each optical sensor (1) and the illumination device (8) face each other in symmetrical positions with respect to the object to be measured (3), respectively. And each lighting device i (
Parallel rays (10), (1) from 8) to the optical sensor (1)
0) are both ends (+3a) of the object to be measured (9),
(9a).

, transducers (4), (4) are semiconductor images in which photodiodes or CODs (charge coupled devices) are arranged in a straight line at predetermined intervals to be orthogonal to the parallel beams (10), (10). Consists of sensors. Each element (11)... is sequentially driven at fixed time intervals by a timing pulse from a pulse generator (13) driven by an arithmetic processing unit (12), and the output signal is sent to a parallel-to-serial conversion circuit (14). , (It), and the processing circuits (15), (15) are converted into series by one signal line.
sent to.

After that, the arithmetic processing unit! (12), each processing circuit (15
), (15), the predetermined calculation based on the signal processing of the optical image magnification 1 dimension or the array interval of the sensor elements (11)... and the optical sensor (1
), (1) using known values such as the distance (wθ) as necessary, and the outer diameter of the object to be measured (8) is calculated.

In the above, for example, the convergence (
12) is detected, use the distance (-) between the optical sensors (1) and (1) to determine the outer diameter dimension (
Wx) is calculated as Wx=WH+2W1. This measured value is outputted by an output device (1B) such as a CRT display or a printer, and if this value is abnormal, an alarm device (17) is activated.

Note that values such as the optical system magnification and the distance (wt) between the sensors can be easily determined by measuring a standard having known dimensions in place of the object to be measured and calculating the results back.

As is clear from the above description, according to this embodiment, the optical sensors (1), (1) and the illumination device (8) are provided at symmetrical positions and facing each other with respect to the object to be measured (9). , (8)
Therefore, when the object to be measured is small, the optical sensor (1),
(1) By decreasing the distance (%#θ) and increasing the distance (1+) when the measured object is large, the object (3
) can detect only the positions of both ends (9a) and (13a), so the outer diameter dimensions of objects ranging from large to small can always be measured with the same optical sensor (1) and (1). Therefore, the measurement accuracy (resolution) and processing time can be kept constant regardless of the size of the object to be measured (9). Dimension measurements can be performed.

Although this embodiment has been described with respect to the measurement of the outer diameter of a rod-shaped object, the present invention is not limited to this embodiment, and can also be used, for example, to measure the length of the object, the surface roughness of the shape, etc.

In this embodiment, the object to be measured (9) is an optical sensor (1).
, (1) and the illumination devices (8), (8), but the measurement end (fla), (9a) of the object to be measured (3) is within the parallel light beams (10), (10). It can be placed anywhere as long as it is facing the light sensor (1), (1). (+1
), (8) In the embodiment, the tonneau/device also coincides with the direction of parallel light rays, but may be deviated in the same direction.

(Effects of the Invention) As is clear from the above explanation, according to the present invention, the measurement accuracy (resolution) and processing time can be kept constant regardless of the size of the object to be measured, and the accuracy and processing time are excellent. It is possible to provide a simple and inexpensive method for measuring the dimensions of an object.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram illustrating an embodiment of the present invention in the case of measuring the outer diameter of a rod-shaped member, and FIGS. 2 and 3 are diagrams illustrating a conventional example. In the drawings (1), (1)... optical sensor (8), (8)... lighting device (9)... measured object (9a), (9a)... measuring end ( 1G), (1
0)...Parallel rays (12)...Arithmetic processing device.

Claims (1)

[Claims] Parallel rays are irradiated onto the object to be measured from opposite directions so that part of the parallel rays is blocked by the measurement end of the object to be measured, and the area of the parallel rays that is blocked by the object to be measured (or 1. A method for measuring dimensions of an object, characterized in that the dimensions of the object to be measured are measured by detecting an unobstructed area.