Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/8803—Visual inspection

Definitions

• This goal is achieved with the aid of a device of the type mentioned at the outset, which is distinguished by the ino light supply from the is and directed essentially parallel Licnt rays under a predetermined Wm ⁇ el on the measuring window, and a light-guiding device, which is carried by the holding device, captures a multitude of light rays starting from a point ⁇ e ⁇ measuring window and presents them parallel or converging in the observation window.
• the observation window can be a viewing tube, an eyepiece, the surface of a lens, etc .;
• a viewing screen can also be arranged in the observation window, on which the light rays strike one another.
• Such a screen can be easily with scales, markings, color reference scales or the like. are provided, which enable a simple comparison of the light beams shown with setpoints.
• Such a light-guiding device captures light beams in a whole, continuous range from different angles, so that, in other words, those angles can be determined at which one color impression changes to the next, in particular with OVIs (Optically Variable Inks) with pronounced fenform ig changing behavior.
• OVIs Optically Variable Inks
• the converging lens is a cylindrical lens. This determines the angular behavior only on the plane normal to the cylinder axis, and the observation window can be viewed with both eyes, for example.
• the light directing device can also be a cylindrical concave mirror, the measurement window being close to the focal plane ⁇ es of the concave mirror.
• the light-guiding device can be formed from prisms or preferably from individual light guides, as are known per se from EP 0 530 818 and which are each assigned to one of the light beams mentioned, which are reflected at different angles.
• a light guide receives a light beam emanating from the measuring window at a certain angle and guides it to the observation window.
• the reflection or transmission scattering behavior can be checked at specific, discrete angles. It is particularly advantageous if the ends of the light guides in the observation window fill out next to one another.
• the Lichtleiteren ⁇ en thus represent colored light spots, which represent the reflection or transmission scattering behavior at certain angles and can be easily detected with a quick glance.
• a further aspect of the invention consists in the creation of a system for the visual comparison of the angle-dependent scattering behavior of a test object with a reference object by an observer.
• This system is characterized by at least two of the described devices according to the invention, which are connected to one another and whose observation windows lie next to one another. This means that Both observation windows can be grasped at a single glance and simply compared with one another.
• a preferred embodiment of the system in particular for flat, flexible reference objects, is characterized in that the receptacle contains a drum to which one or more reference objects can be attached. If the drum is round, you can switch between several reference objects by rotating the drum. Regardless of the shape of the drum, there is considerable space savings with flat, flexible reference objects, since these can be wound onto the drum.
• the system according to the invention enables a number of optical criteria, such as those used as security features, in particular in the case of bank notes, to be checked in a quick and easy-to-use manner.
• the formation of a plurality of test areas on one and the same contact surface makes it possible to simply move the object by hand by moving one load - to pass the corresponding tests to the next one without having to lift or pick up the subject in between.
• the combination with an infrared camera enables additional testing of optical criteria in the infrared range.
• a particularly advantageous embodiment of the system is characterized in that the infrared camera is a black and white CCD camera which is preceded by a blocking filter for the visible light range. It has been found that the simplest commercially available black and white CCD cameras have a sufficient sensitivity in the infrared range, which can be used by connecting an appropriate filter. This solution is much less expensive than using infrared imaging tubes.
• the output of the infrared camera can easily be provided at a corresponding connection of the housing, so that an external monitor can be connected. However, it is particularly advantageous if a monitor is provided which is carried by the housing and connected to the output of the infrared camera, so that the system is largely self-sufficient.
• the infrared test can work with ambient light that falls on the test object as long as it contains a sufficient infrared component.
• the housing carries a second light source, which is directed onto the second region from above, has a significant radiation component in the infrared region and can optionally be switched on. This means that the system is largely independent of the ambient light. It has been found that a particularly inexpensive variant is that the second light source is a filament lamp.
• the concept of the multi-criterion test according to the invention can be refined by making the second region of the support surface translucent in a further preferred embodiment of the system and the housing carrying a third light source which is directed from below onto the second region and has a significant radiation component in the infrared region and can optionally be switched on. As a result, not only the infrared reflection behavior but also the in- infrared transmission behavior of an object can be checked.
• the UV excitation behavior of fluorescent printing inks can be checked.
• the housing has a cover which is arranged above the flat surface and leaves at least one side opening for access to the support pool. This allows ambient light to be shielded from the test areas. It is particularly advantageous if the third area is located away from the opening, thereby reducing the risk of UV radiation escaping from the opening.
• the device u generally designated 1 in FIG. 1, comprises a holding device 2, which is designed in the form of a wire frame and can be brought into abutment on the surface 3 of an object 4 shown in sections.
• the holding device 2 defines a measurement window 5 on the surface 3 of the object 4 and, relative to this, the position of a light supply 6 and an observation window 7, which is visible to an observer 8 on the upper side of the device 1.
• the light supply 6 carried by the holding device 2 directs a bundle of essentially parallel light beams 9 onto the measuring window 5 at a predetermined angle ⁇ .
• the angle ⁇ can also vary slightly within the bundle of light beams 9, for example by a few degrees, up to approximately ⁇ 10 Degree.
• the light beams 10 reflected from each point of the measuring window 5, more precisely the surface 3 of the object 4 at different angles ⁇ _, ⁇ 2 etc., are captured by a light-guiding device 11 and presented to the observer 8 in parallel or convergingly in the observation window 7.
• the light directing device 11 is carried by the holding device 2 and, in the example shown, is a converging lens, the upper side of which forms the observation window 7.
• the observer 8 is offered a juxtaposition of different color impressions 13-16, which correspond to the colors reflected at the individual angles ß ] _, ß2 etc.
• the device 1 can be modified simply by arranging the light supply 6 and the light guiding device 11 on different sides of the measuring window 5.
• the holding device 2 has a corresponding recess into which the object 4 can be inserted so that it is between the light supply 6 and the light directing element. direction 11 is. All of the above and the following explanations therefore also apply in an analogous manner to transmission test devices.
• the light directing device 11 can be both a spherical converging lens and a cylindrical converging lens.
• the measuring window 5 lies approximately in the area of the focal plane of the converging lens, i.e. shortly before, in the focal plane or just behind.
• the light directing device 11 is here a cylindrical converging lens in the form of a half-cylinder, and the figure shows an axially normal section through the cylinder.
• the measurement window 5 lies on the flat side of the half cylinder, the observation window 7 lies on one side of the curved top of the lens.
• the light supply 6 is a channel drilled on the opposite side of the curved upper side, which captures ambient light at its entrance and directs it onto the measuring window 5.
• the light supply 6 is thus embedded directly in the semi-cylindrical light guide 11; in other words, the " light-guiding device II in turn simultaneously forms the cold device 2 for the relative positioning of the light supply ⁇ , measuring window 5, light-guiding device 11 and observation window 7.
• the half cylinder is provided with an opaque coating 18, with the exception of the incidence of the light supply 6, the measuring window 5 and the observation window 7.
• the light supply 6 can also be a light-emitting diode device embedded in the half-cylinder or attached to it.
• the measuring window 5 can also be in, just before, or behind the focal plane of the cylindrical lens. If it does not have a semicircular shape on average, but rather a segment of a circle, ie the cylinder is not divided in half but in the middle, the measuring window can be on the flat side again so that the lens can be placed directly on the object.
• the system shown in FIGS. 3 and 4 is used to compare the angle-dependent reflection or transmission behavior of a test object 4 'with that of a reference object 4 ", with a separate test device for both the test object 4' and the reference object 4" 1 'or 1 "is provided.
• the devices 1', 1" are arranged next to one another and connected to one another (see FIG. 4), their observation windows 7 lying next to one another in order to enable a comparison to be made at a quick glance.
• Each of the devices 1 ′, 1 ′′ again has a light supply 6, a measuring window 5, a light directing device 11 and an observation
• the drum 23 can also offer space for a number of different reference banknotes 4 ′′ and can be rotated so that it is possible to switch between them.
• the receptacle 22 can also be designed for an optional exchange of different reference objects.
• the device 1 ′′ has a support 24 positioned below the measurement window 5 for arranging the test object 4 ′, for example a bill. Corresponding stops 25 are provided on the support 24 for precise alignment of the test object 4 ′.
• FIG. 5 shows a further embodiment of a system consisting of two interconnected devices 1 ', 1 ".
• the system consists of a single, continuous half-cylinder lens 11 similar to the embodiment of FIG. 2, to which a light supply 6 with an integrated light source 6 Observation windows 7, which do not have to be delimited or framed, result on the upper side of the half-cylinder lens 11.
• the system can be placed on a support 24 or fixedly or articulatedly connected to it at 26, on the support 24 there are stops 25 arranged for positioning the test object 4 'and the reference object 4 ".
• FIG. 6 shows an embodiment of a system for optically checking several criteria of flat objects, in particular bank notes.
• the system comprises a housing 30, which provides the user with a substantially horizontal support surface 31 for the placement of flat objects (not shown).
• the support surface 31 is spanned by a part of the housing 30 in the form of a cover 32, the cover 32 leaving a lateral opening in the drawing facing forward for access to the support surface 31.
• the bearing surface 31 comprises a plurality of areas 33 to 36 (indicated by dashed lines in the drawing), on which one (not shown) object can be supported or placed on. Since the support surface 31 passes from one area 33-36 to the next in a flush or flat manner, an object can be moved back and forth simply by moving it between the areas 33-36.
• the areas 31 to 36 do not necessarily have to be arranged next to one another, but can also partially or completely overlap, but there are certain preferences which are explained below.
• the device 1 can be designed as shown previously with the aid of FIGS. 1 to 5 (entire systems according to FIGS. 3 to 5 are also possible) and is therefore not shown further with the exception of its observer window 7.
• the device 1 checks the transmission scattering behavior, it is partly arranged below the contact surface 31, i.e. the support surface 31 or the first region 33 extend into the device 1.
• the housing 30 carries an infrared camera 37, which extends to the. Area 34 of the contact surface 31 is aimed.
• the infrared camera 37 is a commercially available black and white CCD camera which is preceded by a blocking filter 38 for filtering out the visible light area.
• the filter curve of the notch filter 38 is shown in FIG. 7.
• Fig. 7 shows the relative light power transmission in percent, calibrated against air, i.e. 100% corresponds to the transmission through air, over the wavelength in n. It can be seen that in the visible light range (380 nm to 760 nm) the transmission is essentially 0% and rises steeply in the infrared range.
• the output signal of the infrared camera 37 can be provided at an output connection 39 of the housing 30 for the connection of an external monitor (not shown).
• the housing 30 itself carries a small monitor 40, e.g. of the LCD type.
• a “second” light source 41 is arranged in the housing 30 and is directed towards the second region 34 and a significant infrared radiation.
• the “first” light source is that which is arranged in the device 1 itself).
• Conventional, inexpensive filament lamps which have an extremely large infrared component have proven to be particularly suitable.
• an infrared reflection representation of an object on the area 34 can be produced and viewed, for example, on the monitor 40.
• the support surface 31 can be made translucent in the second region 34, for example by inserting a glass pane flush, as indicated at 42.
• a third light source 43 is arranged under the glass pane 42 in the housing 30 and has a significant radiation component in the infrared range and is again preferably formed by a filament lamp.
• the light source 43 in the form of a filament lamp has Area.
• the control of the second or third light sources 41, 43 is carried out so that only one of the two light sources is switched on.
• a third area 35 of the contact surface 31 is formed in the rear part of the cover 32, i.e. As far as possible from the opening.
• a fourth light source 45 is arranged above the third region 35 and has a significant radiation component in the ultraviolet region.
• the fourth light source 45 is covered by a shielding plate 46 in order to prevent a direct view of the observer from the light source 45.
• the fourth light source 45 is preferably a gas discharge lamp. Such lamps require a certain amount of time to start up. In order to avoid waiting times during operation, the fourth light source 45 can be switched on continuously. This means that the third area 35 should be at a certain distance from the second area 34 in order to avoid image disturbances of the infrared camera 37 caused by flickering effects of the gas discharge lamp if the areas 34 and 35 overlap.
• a fourth region 36 which is equipped with an inductive sensor, is also formed on the support surface 31. With the help of this sensor, the presence or optionally also the arrangement of colors with magnetic or metallic particles can be detected. Indicator lights 47 are connected to the inductive sensor of the area 36 in order to optically display the sensor result. The sensor measurements could also be displayed on the monitor 40, or also displayed using the acoustic signal.
• test and evaluation devices assigned to the areas 33 to 36 can be in continuous operation after the system is switched on (apart from the condition that the light sources 41 and 43 should only be operated alternately), or the individual devices can be started up sequentially (apart from the preference that the ultra violet light source 45 should be in continuous operation).
• a single button 48 which triggers these control functions, and / or a rotary selector switch 49 can be used, for example.
• the devices and systems presented can be used for all types of objects and reflection or transmission scattering structures, for example also for kinegrams, incident light and transmitted light holograms etc. It is also possible to further evaluate the image presented in the observation window 7 by machine, for example by recording with a photographic camera or further processing with the aid of a CCD camera and subsequent image transfer, image evaluation, image processing and image archiving methods, as used in the technology nik are known. This further processing is also possible for the output signal of the infrared camera 37.

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• Immunology (AREA)
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• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Physics & Mathematics (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)
• Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
• Inspection Of Paper Currency And Valuable Securities (AREA)
• Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)
• Forging (AREA)
• Devices For Indicating Variable Information By Combining Individual Elements (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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• 1999
  • 1999-11-19 AT AT0080899U patent/AT4200U1/de not_active IP Right Cessation
  • 1999-12-02 HU HU0200071A patent/HUP0200071A2/hu unknown
  • 1999-12-02 EP EP99957683A patent/EP1141681A1/de not_active Withdrawn
  • 1999-12-02 PL PL99348908A patent/PL348908A1/xx unknown
  • 1999-12-02 EE EEP200100294A patent/EE200100294A/xx unknown
  • 1999-12-02 AU AU15306/00A patent/AU1530600A/en not_active Abandoned
  • 1999-12-02 WO PCT/AT1999/000297 patent/WO2000033054A1/de not_active Application Discontinuation
  • 1999-12-02 CA CA002353382A patent/CA2353382A1/en not_active Abandoned
  • 1999-12-02 SK SK751-2001A patent/SK7512001A3/sk not_active Application Discontinuation
  • 1999-12-02 CN CN99815338.9A patent/CN1332845A/zh active Pending
  • 1999-12-02 CZ CZ20011966A patent/CZ20011966A3/cs unknown
  • 1999-12-02 YU YU39301A patent/YU39301A/sh unknown
  • 1999-12-02 SI SI9920092A patent/SI20553A/sl unknown
  • 1999-12-02 BR BR9915945-7A patent/BR9915945A/pt not_active IP Right Cessation
  • 1999-12-02 RO ROA200100605A patent/RO120297B1/ro unknown
  • 1999-12-02 HR HR20010487A patent/HRP20010487A2/hr not_active Application Discontinuation
• 2001
  • 2001-05-29 LT LT2001058A patent/LT4898B/lt not_active IP Right Cessation
  • 2001-06-01 MA MA26220A patent/MA25365A1/fr unknown
  • 2001-06-01 LV LVP-01-86A patent/LV12761B/lv unknown

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