FIELD OF INVENTION
This invention relates to a novel opto-electronic sizing device. This device is particularly used in the measurement of diameter of wire/fibre/ cables, including the oblacity check. The novel design incorporated is also applicable to the family of sister instruments required to count and measure the particulates in clean and/or polluted environment.
PRIOR ART/BACKGROUND
An opto-electronic device is as such known in the art comprising of I.R diode having a wave length of 900 nm requiring an optical condensing system for illumination of the object, a CCD (charge-coupled device) strip to sense the diffracted light passing through suitable optical focusing arrangement and a panel to display the final measurement necessitating pulse amplification and anaylsis using complex electronic circuitry. As a given industry uses a large number of such units on its various extrusion and assembly lines, the monitoring job becomes time consuming and cumbersome operationally to ensure specified quality control.
The above said instrument presently covers a wide range of diameters from 0.03-150 mm. However, a particular industry covers only a restricted range of sizes for their products. Therefore, efficient use of such an instrument cannot be made. Further, this requires relatively larger range of collimating apertures in the path of sensing diffracted light thereby affecting the precision and accuracy of measurement. Further, the CCD strip is expensive and not always the most-suited sensor.
A diameter measuring device available in the art comprising of a transmitter, receiver, processor electronics and a touch screen display in an integrated package.
A thin band of high-speed scanning laser light is projected from the transmitter by a low-power laser source, a scanning mirror, and a combination of optics. The receiver houses a collector optics, photo diode and preamplifier. The laser light signal entering the receiver is used to calculate the distance between the edges of the product. Dimensional data is displayed which can be transmitted to a computer for further processing.
OBJECTS OF THE INVENTION
The main object of this invention is to propose a novel opto-electronic sizing device which provides quality control to both the metallic wire and fiber manufacturing industries.
Another object of, this invention is to propose a novel opto-electronic sizing device which is cost effective with enhanced precision.
Yet another object of this invention is to propose a novel opto-electronic sizing device which overcomes disadvantages of the prior art.
Still another object of this invention is to propose a novel opto-electronic sizing device which results in an enhanced signal to noise ratio.
A thin band of high-speed scanning laser source is projected from a low power IR laser source on to the object, a combination of optics and a
sensor with electronic processing units. The laser signal entering the sensor evaluates the size of the object.
STATEMENT OF THE INVENTION
According to this invention there is provided an improved opto-electronic device comprising of infra-red diode illuminating an object, a diaphragm with collimating apertures limiting diffraction of light from the object and a sensor being approached with such diffracted light to generate electrical power signal, which is transmitted through cables for centralized electronic pulse-processing of units employed is different assembly lines of an industry.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides an opto-electronic device of the present invention comprising of Infra-Red diode of wave length in the range, for example 900-1600 nm, illuminating an object, a diaphragm with relatively smaller range of collimating apertures limiting diffraction of light from the object, a sensor being approached with such diffracted light to generate electrical power signal, which is then transmitted through cables for centralized electronic . pulse-processing of units employed in different assembly lines of an industry.
The I.R diode of the present invention does not require separate optical arrangement for illuminating the object like in the prior art, causing reduction both in cost and noise vis-a-vis the signal strength. Further, smaller range of collimating apertures in the path of sensing diffracted light contributes to enhance the precision and accuracy of measurement.
The sensor used in the invention has a choice of a bank of avalanche-breakdown diodes/micro-thermocouple array, besides the CCD strip.
To ensure specified quality control, provision has been made only for an initial power amplification to ensure impedance matching with signal cables from each unit. The so generated electronic pulses from all the units can then be centrally amplified and analyzed to provide the dynamic (insitu) measurements with reduced cost, better quality control and operational convenience.
The wave length () can be adjusted according to the requirement and also max and min of the diffracted light can be well adjusted to cover dedicated range of envisaged object sizes, d related to one another as follows:
d sin  = n (with IR pulsed laser effective n can be high).
For the instrument covering the larger diameters above 1 mm., direct shadow cum scanner technology has been adopted, without the need for a diffracted signal. However, for the smaller range down to 0.03 mm., a suitable number of dedicated instrument units have been designed adopting the IR laser beam diffraction. Provision can be made either to replace the IR laser diode of appropriate wavelength (900-1600 nm.) keeping a fixed range for diffracted angles accepted and/or to vary the diffracted angular range keeping the same IR laser source in place. The geometry of the 'source to object' and 'object of sensor' distances has been worked out to be 65-75 mm and 35-45 mm respectively so as to eliminate the need for any optical lens in the two mentioned paths (good geometry consideration). For the oblacity check, a parallel set of laser source and the sensor element is added along another perpendicular
axis, having identical geometry otherwise, thereby covering the X-Y plane measurement independently.
The above said device can also be used as particulate counter with the replacement of cable/wire/fibre by a laminar air flow cell containing particulates. The particulate counter is not only required in clean rooms for semiconductor fabrication but is also needed to cover different particulate size requirements of pharmaceutical industry, hospital, operation theaters and environmental pollution monitoring. It is also used in space stimulation laboratory.
It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:-

I CLAIM:
1. A novel opto-electronic sizing device comprising of infra-red diode illuminating an object, a diaphragm with collimating apertures limiting diffraction of light from the object and a sensor being approached with such diffracted light to generate electrical power signal, which is transmitted through cables for centralized electronic pulse-processing of units employed is different assembly lines of an industry.
2. A novel opto-electronic sizing device as claimed in claim 1 wherein the diaphragm is provided with smaller range of collimating apertures, which contributes to the enhancement of the precision and accuracy of measurement.
3. A novel opto-electronic sizing device as claimed in claim 1 or 2 wherein the sensor is such as bank of. avalanche-breakdown diodes, micro-thermocouple array and CCD strip.
4. A novel opto-electronic sizing device as claimed in any of the preceding claims wherein a lens may be provided between the diode and object and another lens between the diaphragm and sensor, have become redundant.
5. A novel opto-electronic sizing device as claimed in claim 4 wherein the distance between laser source and object is approximately 65-75 nm and the distance between the object and sensor is such as 35-45 mm to eliminate need for any optical lens.
6. A novel opto-electronic sizing device as claimed in any of the preceding claims wherein for the oblacity check, a parallel set of laser source and the sensor element is provided along another perpendicular axis, having identical geometry otherwise thereby covering the X-Y plane measurements independently.
7. A novel opto-electronic sizing device substantially as herein described with reference to the accompanying drawings.