KR19980076871A - Material inspection light source - Google Patents

Abstract

Fluorescence-generating dyes were used inside the refrigerant to measure the presence of leaks in the light source used to test leak detection applications in heating, ventilation and air conditioning systems. The light source combines a color-selective reflector having a lamp and an interference filter to provide narrowed emission of the wavelength of light emitted from the light source.

Description

Material inspection light source

The present invention relates to light sources for leak detection in heating, ventilation, and air conditioning systems. In particular, the present invention relates to a light source capable of detecting a substance for re-radiating light at a wavelength larger than the wavelength of light emitted from the light source.

Since chlorofluorocarbon (CFC) refrigerants destroy the ozone layer, it is necessary to develop environmentally friendly alternative refrigerants. DuPont, International Chemical, and other makers have developed hydrofluorocarbon (HFC) refrigerants that are safer for the environment and range from zero to a few minutes of ozone consumption of CFC refrigerants.

Leakage of lubricants such as naphthalimide, perylene, dioxane, or fluorescence by the addition of certain dyes to the refrigerant may be due to the presence of fluorescence present in the leak site when tested under the unique or specific properties of the light source. Can be detected by The leak detection technique is known and described in US Patent Nos. 5,357,732 and 5,421,192 to Richard G. Henry, issued October 25, 1994 and June 6, 1995, each of which is currently licensed to the same assignee. It was transferred.

Detection of the presence of fluorescence applied to the detection being measured results in optimal visibility of fluorescence generation when leaks are detected under light having an emission wavelength between 300 and 700 nanometers. Conventional ultraviolet light sources have been used for this particular application, but did not provide optimal performance as they would inherently produce light within the commonly found range of ultraviolet light between 300 and 450 nanometers.

Investigating the background art representing the subject of the present invention, the US Patent and Trademark Office is directed to the US patent number following the disclosure.

4,558,0144,775,8535,059,790

5,131,7555,156,9765,192,510

5,347,4385,349,4685,394,133

5,399,4995,441,531

Additional patents are known to applicants of the present application, which include:

4,758,3665,149,4535,357,7825,421,192

It is contemplated that patents not related to the above shall be disclosed or claimed as new combinations of functions and elements outside the scope of the present invention.

The intention of the device is to provide a light source that serves to provide an optimized unit for use in the relevant industry or technology required for the aiming of light within a particular wavelength in a material caused by fluorescence. This is done in the leak detection industry provided by the non-destructive testing industry. As examples of both, objects such as dyes may emit brighter fluorescence under light sources that emit in the range of 300 to 500 nanometers, whereas no luminescence or microfluorescence is usually detected under a light environment of wavelengths.

Historically, light sources have used this type of application for large-capacity alternating lamps operating at either 110 or 220 volts. The lamp, known as PAR 38, was manufactured by Philips and another manufacturer. Typically, the lamp is produced in the range of 100-200 watts, with the actual amount of light emitting above the desired range to produce the required fluorescence response. The lamp also generates a lot of heat and uses ballasts to provide additional volume and weight.

Since then, self-releasing lamps have been developed to practically overcome the previous drawbacks. However, this tends to be relatively long preheating cycles and is very sensitive to voltage surges, causing light to turn off, resulting in long cooling cycles following different preheating cycles.

Recently, pseudo lamps filled with gas such as halogen type small direct current lamps or xenon have been developed. The lamp has the advantages of small dimensions, light weight and no ballast, which is not affected by voltage surges or spikes. It also provides portability and can be powered by a battery. The lamp, however, does not provide a huge output of light in the required range, and therefore no efficient fluorescence has been done to observe the material with sufficient brightness required by all users. This is probably the result of the use of a smooth metal reflector, such as aluminum, and lacks the beam focus in the region of fluorescence, i.e. for the sufficient tactile light of the leaking region.

It is therefore an object of the present invention to provide a durable, lightweight, light source that is free of voltage surges, and to effectively produce high power light of the wavelength required for fluorescence as the above-mentioned fluorescent dyes.

Other dyes are used for fluorescence of different wavelengths in the field of leaks and crack detection and nondestructive testing. Fluorescence is usually defined as the re-emission of light at a wavelength greater than the wavelength of light emitted from the light source at the location of the test.

The elements in the optical system of the present invention are based on the use of tungsten halogen lamps with integrative reflectors and provide an effective optical system that includes lamps similar to the arrangement of lamps with reflectors and whose characteristics are determined by reflector design. Normally single-ended tungsten halogen lamps as described herein are fixed to point the reflector axis with the base from the reflecting mirror vertex facing backwards. The reflectors provided are often focal reflectors that define a point at a distance from the reflector and the axis of the reflector or focus light generated by a more or smaller internal lamp. The reflector geometry used for this purpose is that in a conventional ellipse, the lamp filament is in the first focus of the ellipse and is focused in the second focus. However, if the reflector is parabolic, it may be a collimator reflector that generates parallel beams of light.

Many reflectors used in halogen lamps refer to the use of facet structural surfaces or facets rather than smooth surfaces to modify the light distribution. This arrangement can improve light uniformity and increase the beam angle or crush or smooth the light-dark edges. The facet range on the face of the reflector ranges from clearly visible facets to barely visible grains, with the effect of facets being less or more obviously corresponding. The lamp having the combination in the correct parabolic or elliptical shape can precisely control the focus. The use of smooth aluminum reflectors does not allow the geometric balance and dimensional stability provided in glass reflectors based on halogen lamps in recent years. Thus, if the material selection for the reflector is glass, the reflector surface having an inner hemispherical shape is suitably coated to obtain the required reflection characteristics. This coating is commonly applied by vapor deposition. Known glass reflectors have full dimensional stability and the surface can be easily modified by applying a coating for the reflective surface.

The detection of the fluorescence required when testing the material is limited in closer proximity to the wavelength of light emitted from the light source. The precision of the resolution and the control of the wavelength can be controlled for the use of a reflector with color selective coating. Color-selective coatings produce their reflective properties through the phenomenon of interference. It consists of many (more than two dozen) very thin layers, alternating between high or low refractive index materials, with only one quarter of the wavelength of the thick light, respectively. Any reflection curve that actually allows to be achieved by means of fine tuning and the thickness of the layer is combined. The maximum reflectivity is almost 100% and there is practically no absorption of radiation in the region of low reflection forces. Thus, the color selective reflector is lossless and passes without being reflected by the reflector.

The most known member of the color screening system is a cold light reflector, which reflects visible light between 300 and 750 nanometers and allows radiated heat to pass through unobstructed back through glass reflections. This arrangement greatly reduces the heat load on the mirror surface or the object. Blue light reflectors and ultraviolet reflectors are other types of reflectors. In the case of the blue light reflector, it is reflected only in the blue light region of the stack rum (between 400 and 500 nanometers), while in the case of the ultraviolet light reflector, it is reflected only in the ultraviolet range emitted by the lamp. This range is typically measured between about 300 and 400 nanometers.

The cold light reflector fluorescent dye, which is extremely satisfactory in all fluorescent dyes, is excited for fluorescence by light in the same nanometer range as produced from cold light reflectors, ie from 300 to 500 nanometers. Light produced outside this range can be wasted in large quantities to produce the required fluorescence and degrade the user's ability to see fluorescence clearly. Therefore, the color selective reflector ideally provides the excitation wavelength (for fluorophores) provided with a narrow bandwidth of light output reflected from the lamp, and provides precision that cannot be achieved using other types of reflectors.

The lamp is also effective at the width of the stack spectrum within the range required for fluorescence and provides the extremely strong density of precisely focused light required for leak detection techniques. In the result of this arrangement the focus can be produced as high as 10,000 to 15,000 candles, especially from extremely small light sources of 6 ° to 14 ° beam spread. The narrowing beam spread usually results in greater candles and greater fluorescence density.

It can also limit the output of the spectrum from the reflector lamp to be further narrowed by the use of an optical filter. The optical filter may be an integral part of the reflector unit or may be independent of the reflector lamp other than its associated use. In both examples, the light output from the reflector lamp is reduced to pass only the wavelengths required for the application. This may be possible for a filter used solely for safety purposes by the use of transparent glass which does not limit the bandwidth of the light passing through. Typically, this is possible with two types of filters that can be used as absorption filters or color filters. The dichroic filter works again on the same principle of interference as discussed above with regard to the use of the dichroic filter.

In addition it is also possible to tailor the light output in the light source according to the invention by the use of shields or eyewear by the user allowing only light of a certain wavelength to pass. Eyewear can take many forms, including glasses, goggles, and face shields. Therefore, eyewear allows for ultimate fine tuning of the wavelength for the detection of fluorescence when used in combination with a filter.

In the arrangement according to the present invention, in the member constituting the housing, a light source including a color-selective reflector having a lamp included therein is fixed together with a reflecting facet color filter surface surrounding the portion of the lamp including the filament. In addition, the front of the lamp assembly controls the light emitted therefrom within the specific range reflected by the color selective reflector and in all cases is an absorption type filter which acts to limit the specific wavelength of the light emitted from the light source. It is a filter lens. The final filter can be removed when used with blue and ultraviolet light reflectors.

The on / off switch is also included inside the container providing control of the connection to an external power source for the light source. Therefore, this can be seen by means of a combination of dichroic reflectors and absorption type filters located in front of the light source, where light of a predetermined narrow beam can be emitted from the light source of the current unit. Further features and advantages of the invention will appear from the detailed description of the preferred embodiment of the invention as shown below.

1 is a cross-sectional view of a light source for use in testing a material that re-radiates light at a wavelength greater than the wavelength of light emitted from the light source according to a preferred embodiment of the present invention.

2 is an exploded view of a light source according to the present invention;

Figure 3 is a perspective view of eyewear comprising a long wavelength passing material for use with the light source of the present invention.

4 is a perspective view of a shield including a long wavelength pass material for use with the light source of the present invention.

Explanation of symbols on the main parts of the drawings

2: front cap 3: rear cap

4: filter lens 5: compression spring

The present invention enables the best understanding by referring to the drawings in which like parts are denoted by the same reference numerals.

1 and 2, the construction of the housing of the preferred embodiment of the light source of the invention consists of phenolic, plastic or a suitable material. The unit is cylindrical in structure and hollow and attached to either end, where all the front and rear caps 3 are made of aluminum or other suitable material. As shown in the figure, the front cap 2 is opened outward and the BIS lens filter No. It is located in a straight line behind the filter lens 4, which is a preferred embodiment of the PS-600. The filter provides maximum light transmission at a wavelength of approximately 400 nanometers, at which about 82% of the light is transmitted through the filter lens.

The compression spring 5 is located directly behind the filter and is an aid in which the lens 4 and reflector 6 are located in relation to a suitable distance in the housing and provides shock-absorbing assistance.

The reflector 6, which is located behind the filter lens 4 and is separated by the compression spring 5, is a glass reflector, preferably in a mold of the usual type, referred to in the lighting industry by the letters MR. Numbers following the MR letter indicate a 3.18 mm (1/8) increase in reflector diameter. In this embodiment, the MR16 reflector has a diameter of about 51 mm or about 2.0.

Units of this type are produced by several major lighting companies in the United States, Europe and Japan. The reflector is produced by General Electric Company, Oslo-Sylvania, and the like.

All reflectors are widely used to be low-voltage, high-contrast lamps used for applications such as display lighting. As indicated above, the mold reflector of the type mentioned is typically surface treated with a coating that reflects on the front face 9. This surface is a conventional multilayer interference filter arranged to reflect visible light from a reflector. The front surface 9 has one facet 7A which provides a uniform beam of illumination from the lamp 10. In particular, the lamp (tungsten halogen) selected herein may be an MR16 type EXT which provides a narrow spot type beam with about 12 ° diffusion. The extension from the rear surface 8 of the reflector 6 is fixed to the part 14. The apertures that extend through the reflector at the vertices are typically arranged to have rectangular apertures to allow for a suitable range of lamps (bulbs), such as lamp 10, which extends. The lamp 10 has a filament portion 10A and a neck portion 10B, and the filament 11 included herein is connected to the terminal 12 and the terminal 13 (not shown) behind the lamp. The terminal 13 is not visible because it is parallel to the terminal 12. This lamp is a conventional white light source, such as a halogen lamp with enclosed filament portion 10A glass or a neck portion 10B composed of quartz. The lamp 10 is secured in a neck portion 14 having a filament portion 10A extending beyond the front surface 9 of the reflector 6. A socket 15 accommodating the terminals 12 and 13 is provided for connecting the circuit conductors 16 and 17. The socket 15 is made of ceramic or similar material. Conductor portion 16A extends to on / off switch 18 and continues through conductor portion 16B to external power source 20. The other conductor 17 extends directly from the socket 15 to the power source 20.

The MR16 lamp shown here typically operates at 12 volts and consumes about 50 watts of power. The power source 20 may be composed of a battery, a generator or a dynamo. The switch 18 is used to switch the light source on or off during the use of a new light source in the test of a material that re-radiates light at a wavelength greater than the wavelength of light emitted from the light source of the present invention.

The heat shield 19 extends around the rear part of the reflector 16, the fixing part 14, the socket 15, and is held in place against the rear of the reflector by the rear cap 3 part. Heat shields are required as long as there is light that does not transmit in the forward direction to the reflector 6, which is transmitted as heat through the rear surface, and the reflector 6 of the neck 14 holds the current unit to close enough during operation. Help

It should be noted that the halogen lamps included herein having a complete MR16 type reflector are useful with other sources previously mentioned and Osm-sylvania. The lamp 10 is preferably attached to a fixed portion 14 which can prove to be a suitable adhesive, such as a silicone or epoxy based adhesive.

It should be noted that the unit includes a color screen reflector as described. Color-reflected coatings produce specific reflection characteristics through interference. These (very thin layers of 40 or more) constitute alternating materials each having only one quarter of the wavelength of the light thickness and having a high or low reflection index. Thus, the reflectivity is almost 100% with practically no absorption of radiation in the region of low reflectivity. A well-known member of this group of light sources of this embodiment may be of a type referred to as a cold light reflector that reflects only visible light between about 400 and 700 nanometers and allows any thermal radiation to pass unobstructed through the glass reflector backwards. . Therefore, the heat load or target on the appearing surface is greatly reduced.

When the effective light source is intensified, the user uses a shield 40 or eyewear 30 that includes a long pass material 31 or 41 to also limit the wavelength of light from the light source of the present invention.

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Claims (23)

In the light source for inspection of a material that radiates light at a wavelength larger than the wavelength of light emitted from the light source, Color screening reflectors, A lamp located between the color selective reflector and the material, A lamp assembly having a lens filter positioned between the lamp assembly and the material, The lamp is connected to an electric power source and is operated by the electric power source for light emission, The color selective reflector acts to reflect a selected portion of light emitted from the lamp, The lens acts to further limit the light reflected by the color selective reflector from the lamp, Light emitted from the light source is limited to a predetermined range effective to enhance re-radiation of light from the material. The method of claim 1, And the lamp is a tungsten halogen lamp. The method of claim 1, And the color-selective reflector is a focus reflector. The method of claim 1, The color-selective reflector is oval light source for the material inspection, characterized in that. The method of claim 1, The color-selective reflector is a parabolic shape light source for the material inspection, characterized in that. The method of claim 1, And the color selective reflector has a collimated surface. The method of claim 1, The color-selective reflector has a facet surface. The method of claim 1, The color-selective reflector is a light source for the material inspection, characterized in that made of glass. The method of claim 1, The color-selective reflector is a cold light reflector that reflects light wavelengths between 400 and 700 nanometers. The method of claim 1, The color-selective reflector reflects light within a blue wavelength emission range having a wavelength mainly between 400 and 600 nanometers. The method of claim 1, The color-selective reflector is a light source for a material inspection, characterized in that mainly reflecting light within the ultraviolet range between 300 to 450 nanometers. The method of claim 1, And said lamp assembly further comprises a protective shield acting as an absorption filter. The method of claim 1, And the lamp assembly is pre-focused at a predetermined beam spread. The method of claim 1, The lens filter is a light source for a material inspection, characterized in that the interference filter. The method of claim 1, The lens filter is a light source for the material inspection, characterized in that the absorption filter. The method of claim 1, The material is a material inspection light source, characterized in that the dye for leak detection. The method of claim 16, And the dye is selected from the group comprising naphthalamide, perylene, thioxanthin, commarin and florisine. The method of claim 1, And said wavelength of light emitted from said source is further defined by filter lens eyewear or use, further by the use of a filter shield used by the user of said light source. The method of claim 18, And the wavelength of the light emitted from the source is further defined by the inclusion of long pass-through material contained in the filter lens eyewear or the filter shield. The method of claim 1, And a shock absorbing compression spring positioned between said lamp and said lens filter, operative to maintain a suitable spatial relationship between said lamp and filter lens. In the light source for the material inspection to re-radiate light at a wavelength larger than the wavelength of light emitted from the light source, Said color-selective reflector reflecting light within an emission range having a wavelength primarily between 300 and 600 nanometers, A lamp assembly having a lamp positioned between the color selective reflector and the material, The lamp is connected to an electric power source and operated in response to the electric power source for light emission, The color selective reflector acts to reflect selected portions of light emitted from the lamp, The light emitted from the light source is limited to a predetermined range effective to enhance re-radiation of light from the material. The method of claim 21, The color-selective reflector is a light source for a material inspection, characterized in that for reflecting light mainly in the blue emission range having a wavelength between 400 and 600 nanometers. The method of claim 21, The color-selective reflector mainly reflects light in the ultraviolet range between 300 to 450 nanometers.