JPS58117403A - Method for measuring diameter - Google Patents

Abstract

PURPOSE:To display the diameter, by utilizing the fact that the light transmittance of optical fiber is changed by the change in bending curvature of the fiber, winding the fiber around the outer surface of a round rod shaped material to be measured, and transducing the light output, which is changed in response to the length of the winding, into an electric signal. CONSTITUTION:In a light emitting part 1, a DC power source is applied to a DC circuit of an LED11 and a current limiting resistor 12, and the light is always transmitted through the optical fiber 2. In a light detecting part 3, a DC power source is applied to a DC circuit of a photodiode 31 and an output resistor 32. A current which is proportional to the amount of the received light is flowed, and a voltage drop is generated across the resistor 32. With respect to the change in the diameter of the material to be measured, the output voltage Vo from the light detecting part 3 hs a linear proportional relationship within a certain range. The linear part excluding a saturated area is made to be the measurable region. The generated voltage Vo is calibrated by a known diameter value, and the diameter of the material to be measured is directly displayed on a display.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a diameter measuring method most suitable for measuring the diameter of a round bar-shaped object to be measured.

Conventionally, a caliper or the like has been used to measure the diameter of an object to be measured. In particular, calipers are widely used due to their high accuracy and ease of use. However, as is well known, calipers read the scale by a combination of a main scale and a vernier scale, so
It was difficult to see liI and ri and it was difficult to measure quickly, which was inconvenient.

The present invention provides a method for easily measuring the diameter with high accuracy and reading IIL#.

The present invention takes advantage of the fact that the light transmittance of an optical fiber changes due to changes in the curvature of the optical fiber, and wraps the optical fiber around the outer periphery of a round rod-shaped object to be measured. converts the optical output into an electrical signal,
It is displayed as a diameter.

Figure WN2 is a configuration diagram showing a specific embodiment of the present invention.

Light emitting part IK optical fiber 2 using light emitting diode (LED), laser diode, incandescent lamp, etc.
One end is connected to the other end, and the other end is connected to a photodetecting section 3 using a light receiving element. As the light-receiving element, it is possible to use a 7Ototra/distor using silicon (St) or an element using Cd8 (cadmium sulfide). The odor body circuit of the light emitting section 1 and the light detecting section 3 is shown in Fig. 112.

Light emitting 11S1aLED11! -1sI151M resistor 12
A DC power supply is applied to the series circuit of the photodiode 31 and the output resistor 32, and the light is constantly emitted at a constant luminous intensity, and the light is transmitted to the optical fiber 2. On the other hand, the photodetector 3 applies a DC power to the series circuit of the photodiode 31 and the output resistor 32. Power is applied, and the LID II light that has passed through the optical fiber 2 is received by the photodiode 31 . The photodiode 31 causes a current to flow in proportion to the amount of light received, causing a voltage drop across the resistor 32. If the output voltage of the resistor 32 is amplified and applied to a meter, changes in the amount of light received can be displayed in an analog manner, and if the output voltage of the resistor 32 is converted from tA/D to drive a digital display, a digital display is possible. .

The optical 7 eyer 2 (in this example, a plastic optical 7 eyer with a core diameter of 710 svn and a cladding diameter μm was used) is as shown in FIG.
The diameter can be measured by turning the outer circumference of the object to be measured 4 once and from the light output (received light output) value at that time. That is, the third
As shown in the figure, the output voltage V of the photodetector 3 has a linear proportional relationship in a range 11 with respect to a change in the diameter (■) of the object to be measured. Therefore, if the 1-generated voltage V@ is calibrated with a known diameter value by setting the straight line portion as a measurable region excluding the saturated region, the diameter of the object to be measured can be directly displayed on the display.

The measurable range can be changed by appropriately replacing the light emitting element, light receiving element, optical fiber, etc.

Note that in the above explanation, only the case of measuring the diameter of the object to be measured has been shown, but as described above, the present invention utilizes changes in light transmittance due to changes in the curvature of the optical 7-eyeper. It is also possible to measure the curvature of an object. Furthermore, by directly multiplying the circumference by pi, the circumference of the object to be measured can be measured.

As is clear from the above, according to the present invention, the diameter of a round bar-shaped object to be measured can be easily and highly accurately measured.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a specific implementation of the present invention. [FIG. 2 is a schematic diagram specifically showing the light emitting section 1 and the photodetecting section 3 shown in FIG. 1, and FIG. 3 is a diagram showing the generated voltage characteristics with respect to the diameter change according to the present invention. 1... Light emitting section, 2... Optical 7 eyeper (. 3... Light detection section, 4... Measured object, 11... LE
D. 12.32...Resistor, ax...Phototransistor. Agent Tatsuyuki Unuma (and 2 others) 11th 1st 2161st

Claims (1)

[Claims] 0) A fixed amount of light is sent from one end, and the light transmitted through the circular part is sent to the receiver from the other end. A method for measuring a diameter, characterized in that the diameter of the object to be measured is measured from a change in output light that changes in accordance with a change in the object.