DE202014102853U1 - Device for detecting the optical quality of a transparent material surface and its use - Google Patents

Abstract

Device for detecting the optical quality of a transparent material surface (10), in particular glass, characterized in that the device has at least one scanning device (12) for scanning the transparent material surface, at least one recording device (14) for recording an electromagnetic output signal and at least one with the Scanning device (12) and / or recording device (14) has connected evaluation device (16), wherein a) the scanning device (12) supplies the electromagnetic output signal, b) the recording device (14) records the electromagnetic output signal and c) the evaluation unit (16) Standard deviations in the optical quality of the transparent material surface are determined and displayed.

Description

Field of the invention

The invention relates to a device for detecting the optical quality of a transparent material surface, in particular glass and their use.

Such devices are primarily used to detect damage or - often irreversible - aging processes on transparent material surfaces such as glass.

For example, all materials are subject to - often irreversible - aging due to chemical and physical changes. This time-dependent influence on the material can either be limited to the surface and / or affect the entire component. For organic substances such. As plastics deteriorate deterioration of the product properties such as color, transparency, stiffness, tensile strength and elongation at break. Without protective measures, these processes can be used after only a few months or years and make the component unusable.

To protect against aging by thermal or solar oxidation stabilizers are added in small quantities to most industrial plastics (about 0.02 to 1.5%). The two most important groups of these additives are antioxidants for binding and deactivation of the radicals formed during the oxidation, as well as UV stabilizers for absorbing the radiation, binding of radicals and deactivation of energetically excited molecular groups.

In particular, the influences of the PVB films used for laminated safety glass are relevant in terms of the durability of the composite effect. The most damaging influences include UV radiation and moisture.

In addition to the atmospheric conditions, production-related and installation-related causes can contribute to a negative durability and thus reduced composite effect. The reasons for this are manifold and may reveal themselves only temporarily offset.

In addition, material surfaces such as, for example, glass can also be damaged by mechanical forces such as, for example, material removal by stone chipping and the like. In such a material removal the glass splits in irregular particles from the smooth surface. This creates irregular structures that scatter light in all directions, no matter which direction the incident light comes from. Such - depending on the extent of material removal fine or coarse - damages are particularly when using z. As glass in car windows relevant because (micro) damage the discs at z. As darkness, moisture and backlight pose a significant security risk that can lead to accidents.

State of the art

From the DE 693 07 722 T2 For example, a transparent material inspection method is known in which a camera looks through the transparent material at a background uniformly illuminated with neon tubes to detect defects trapped in the material. In order additionally to detect dust particles lying on the material surface, the material surface facing the camera is illuminated by a lamp which, due to its construction, generates light beams which are parallel to one another and which therefore produces a light which is parallel to the scan line and diffuse in the direction of the scan line.

In the DE 2 261 460 A A method is disclosed for detecting defects in a transparent material, in which each surface side of the transparent material is illuminated with a light which is parallel to the scan line and diffuses in the direction of the scan line. The material surface is observed with a camera, wherein the illumination device arranged on the side of the camera serves to detect surface defects and the illumination device arranged on the side opposite to the side of the camera serves to detect defects included in the transparent material.

task

The object of the present invention is therefore to enable a reliable recognition of the optical quality of a transparent material surface such as, for example, glass.

solution

This object is achieved by the inventions having the features of the independent claims. Advantageous developments of the inventions are characterized in the subclaims. The wording of all claims is hereby incorporated by reference into the content of this specification. The inventions also include all reasonable and in particular all mentioned combinations of independent and / or dependent claims.

In the following, individual process steps are described in more detail. The steps do not necessarily have to be performed in the given order, and the one to be described Method may also include other, not mentioned steps.

• a) die Abtasteinrichtung das elektromagnetische Ausgangssignal liefert,
• b) die Aufnahmeeinrichtung das elektromagnetische Ausgangssignal aufnimmt und
• c) die Auswerteeinheit (16) Normabweichungen der optischen Güte der transparenten Materialoberfläche ermittelt und anzeigt. Die Ermittlung evtl. Normabweichungen der optischen Güte der transparenten Materialoberfläche erfolgt i. d. R. durch den Abgleich der übermittelten Werte für das elektromagnetische Ausgangs- sowie des elektromagnetischen Eingangssignals. Diese Werte können bspw. in Relation zu zuvor ermittelten bzw. bestimmten oder vorgegebenen Referenzwerten gesetzt werden, sodass evtl. Abweichungen hiervon angezeigt werden.

The device according to the invention for detecting the optical quality of a transparent material surface, in particular glass, is characterized in that it comprises at least one scanning device for scanning the transparent material surface, at least one receiving device for receiving an electromagnetic output signal and at least one evaluation device connected to the scanning device and / or receiving device having,

• a) the sampling device supplies the electromagnetic output signal,
• b) the receiving device receives the electromagnetic output signal and
• c) the evaluation unit ( 16 ) Determines and displays standard deviations of the optical quality of the transparent material surface. The determination of any deviations in the optical quality of the transparent material surface is usually carried out by adjusting the transmitted values for the electromagnetic output and the electromagnetic input signal. These values can be set, for example, in relation to previously determined or determined or predetermined reference values, so that possible deviations from these are displayed.

According to the invention, the scanning of the transparent material surface can take place in any desired manner, and in particular in that the scanning takes place by applying a radiation to the surface such that the surface characteristics are the radiation transmission or the reflection, the refraction or change of the radiation properties from or through the surface influence. In this case, electromagnetic radiation, such as visible light, infrared, radio waves or the like. Be used. Alternatively, it is also possible to use other types of waves or radiation, such as, for example, nuclear radiation or sound (for example ultrasound).

An electromagnetic wave is a wave of coupled electric and magnetic fields. Examples of electromagnetic waves are - as stated - radio waves, microwaves, heat radiation, light, X-rays and gamma radiation. The interaction of electromagnetic waves with matter depends on their frequency, which can vary over many orders of magnitude. The transversality may be violated, eg. B., if - as in plasma oscillations (plasmons) - carrier chemical properties, eg. B. metallic or bonded electrons are involved. Accordingly, the sources, propagation properties and effects of the radiation differ in the different regions of the electromagnetic spectrum.

Unlike sound waves, for example, electromagnetic waves do not require a medium to spread. They propagate in the vacuum, regardless of their frequency at the speed of light. In matter, the speed of light is reduced.

In a preferred embodiment of the invention, the scanning device has at least one transmitter and / or at least one detector of an electromagnetic signal. The transmitter is preferably a light emitter, in particular a light emitting diode or a laser diode, and the detector is a light detector, preferably a photosensitive resistor (LDR) or a photodiode.

A radiation detector according to the invention is understood to mean a component for measuring electromagnetic radiation. Depending on the design of the detector, radiation of different wavelengths can be detected. In general, it should be pointed out in this context that the device according to the invention-depending on the transmitter and / or detector used-can use any wavelength for the detection of the optical quality of a transparent material surface and is therefore not limited to any wavelength.

Many radiation detectors can also serve as particle detectors. The operation of a radiation detector is based i. d. R. on electromagnetic interactions of the photons, so the field quanta of the electromagnetic field, with the electrons or nuclei of the detector material (often noble gases or semiconductors). Depending on the type of detector, various interaction mechanisms are used. The most common is the interaction with the electrons (the photoelectric effect). If the energy of the photon is equal to or greater than the binding energy of the electron, the electron can be released from the atomic network by the photon. This electron can be drifted by applying an electric field to the anode, where it can be detected by measuring the electric current or the electric charge. The light in the visible and near infrared range can knock out the relatively weakly bound valence electrons, the significantly higher energy X-rays and gamma rays interact predominantly with the more strongly bound internal electrons.

Examples of such transmitter / detector systems which can also be used for the device according to the invention are:
Photocells for the detection of light (NIR to UV) and its quantum energy; Photomultipliers as highly sensitive detectors (up to single photon detection) for NIR to UV, coupled with scintillators also for high-energy radiation (X-ray or gamma radiation); Photoresistors, photodiodes and phototransistors for detecting visible light, NIR and UV; CCD sensors for spatially resolved detection of visible light, NIR and UV; Counter tubes for detecting most types of ionizing radiation; Silicon or germanium semiconductor detectors for the detection of high-energy ultraviolet radiation (vacuum UV, extreme UV), as well as x-ray and gamma radiation; Bolometer, thermocouple, Golay cell and pyroelectric sensors (eg in low-temperature pyrometers) detect the radiation due to the temperature differences it causes; Photographic plates or films in which the radiation causes permanent chemical changes that can be visualized by the development; IR sensor cards convert infrared radiation into visible light by nonlinear effects; Scintillation counters convert the energy that releases the interaction of high-energy quanta or elementary particles in a scintillator into flashes of light and measure their quantum or particle energy via the amount of light per flash.

An optical proximity switch consists of a light emitter (often a light emitting diode or a laser diode) and a light receiver (for example, a photosensitive resistor (LDR) or a photodiode). The receiver (evaluation unit) evaluates the intensity, the color or the duration of the light received by the light emitter.

Light sources with a wavelength of 660 nm (visible red light) and 940 nm (infrared range) are frequently used as the light source. Infrared light has the advantage of achieving a longer range on dark materials. The advantage of the visible red light is the easier adjustment of the sensor system by the visible light spot. For particularly precise applications (small parts detection, high repeatability) i. d. R. red laser light used.

In the case of the light barriers, the light beam emitted by the transmitter is either sent directly to the receiver (through-beam sensor) or reflected by a reflector (reflection light barrier) and then picked up by the receiver. In both cases, the signal is triggered when the light beam is interrupted.

A light sensor has integrated the optical transmitter and receiver in one unit. He responds to the reflected light from the object. The switching distance is therefore dependent on the reflection properties of the object surface.

Proximity switches with laser triangulation have a spatially resolving photodiode or a CCD line as a sensor.

Other optical proximity switches respond to the reflected color, include a color sensor and threshold switch.

The fact that the optical quality of a transparent material surface is evaluated via the emitted and received electromagnetic signal makes it possible to quickly and conveniently detect the occurrence of an undesired material property and to react accordingly, for example by replacing a car glass pane.

In a particularly preferred embodiment, visible (or infrared) light is used and directed onto the material surface so that it is reflected by it to a corresponding light (or infrared) sensor / detector.

In a further preferred embodiment, the device is characterized in that the at least one transmitter and the at least one detector are arranged relative to one another such that the detector receives the electromagnetic signal of the associated transmitter by reflection on at least one reflection means, preferably a mirror or foil, wherein the signal has passed through the material surface at least once.

According to a variant, the at least one detector is arranged such that it receives the electromagnetic signal from a transmitter or transducer mounted on the opposite side of the transparent material surface. In this arrangement, transmitter and detector are located on the same side of the material surface. The signal strikes the surface of the material, passes through it and encounters at least one reflection means, which throws the signal back to the detector. The signal then passes through the material surface once more. The reflective means is preferably arranged so that in the case of a disc it is on the other side of the disc and the signal thus passes through the material surface and the disc before it hits the reflecting means.

As already mentioned, the generation of the electromagnetic signal can be done in any way depending on the scanning method used. Thus, when using continuous, reflected or refracted radiation, the scanning device can have a radiation receiver which contributes the electromagnetic signal Receiving the transmitted, reflected or refracted radiation generated, wherein the electromagnetic signal is started, stopped and / or resized depending on the presence or absence or the intensity level of the transmitted, reflected or refracted radiation.

Accordingly, when using visible (or infrared) light, the scanner may comprise a light source (such as a helical or light emitting diode) and a light sensor / detector (such as a phototransistor, a photosensitive resistor, a photocell, or the like). When scanning with the change in the radiation properties, for example, with a frequency shift of the same or changing the intensity, worked, so the scanner has a responsive to the change means, which converts the same into a corresponding electromagnetic signal.

In a further preferred embodiment, the device has an evaluation device, wherein the evaluation device comprises a digital display, which provides a numerical display for the determined standard deviation of the optical quality of the transparent material surface.

Preferably, the device according to the invention is characterized in that the scanning device itself comprises a receiving device and / or an evaluation device.

It is further preferred if the device according to the invention has attachment means for releasable attachment to the transparent material surface, in particular disc. These attachment means may be arranged on the scanning device, the receiving device and / or the evaluation device. Examples of such, a releasable attachment to the transparent material surface enabling, attachment means are for. As a suction cup or a suction plate, but also other, known in the art mounting means are included according to the invention. It may, for example, also be an attachment outside the transparent material surface, in the case of a motor vehicle on the exterior mirror or the body (eg engine hood). The attachment can also serve to set a defined distance and / or angle of the scanning device and / or receiving device. There may also be separate attachment means for the scanning device and the receiving device if they are not accommodated in a common housing.

The device may additionally comprise means for determining the distance. This can ensure that the measurement is made at a certain distance from the surface. The measurement of the distance can be wireless or mechanical. For example, a laser range finder may be part of the device. It may also contain a plurality of means for determining the distance and / or means for determining the relative position of the device, for. B. always to ensure a certain angle to the surface. The device may therefore also contain means which evaluate the values measured by the means for determining the distance and / or the position and determine whether a determination of the quality can be carried out. This can also be signaled to the user by appropriate means. This can also be done in the evaluation unit.

It is particularly preferred if the device according to the invention is designed in the form of a laser gun and so is particularly easy and intuitive to handle.

Furthermore, the use of a device according to the invention for detecting the optical quality of a transparent material surface, in particular glass, is detected.

The device is used in particular for the measurement of windows of vehicles, in particular of motor vehicles, in particular cars. This means cars any form of motor vehicle with windscreens, d. H. also trucks, buses or similar vehicles.

This may for example be a method in which the device is attached to the motor vehicle and then the quality of at least one disc is measured. It may be necessary to calibrate a reference disk beforehand. It may also be necessary to thoroughly clean the glass beforehand.

The measurement can be made point by point or by scanning the surface. Depending on the measuring method, specific points of the surface can be measured or an average value for a specific area can be determined. For example, if this area includes the usual field of vision of the driver, an average value for the quality in this area can be determined in this way. At the same time, local disturbances, eg. As scratches, recorded and reported. It is preferred to investigate whether the measured values are within predefined limits. Depending on the values obtained, the disc can be repaired or replaced.

Further details and features will become apparent from the following description of preferred embodiments in conjunction with the dependent claims. In this case, the respective features can be implemented on their own or in combination with one another. The possibilities to solve the problem are not limited to the embodiments.

For example, area information always includes all - not mentioned - intermediate values and all imaginable subintervals.

An embodiment is shown schematically in the figures. In detail shows:

1 a schematic representation of the device for detecting the optical quality of transparent material surfaces;

2 a schematic representation of the further embodiment of the device for detecting the optical quality of transparent material surfaces;

3 a schematic representation of the further embodiment of the device for detecting the optical quality of transparent material surfaces;

4 a schematic representation of the device as a laser gun.

1 shows a schematic representation of the device. The scanning device 12 includes at least one transmitter 18 , which sends a signal in the direction of the material surface 10 sends out (the dashed lines). The signal reflected from the surface of the material (or the absence of such a signal) is received by the detector 20 in the receiving device 14 received and in the evaluation 16 evaluated. The evaluation device 16 does not have to be part of the recording device 14 but may also be arranged outside the device. In this arrangement, asperities and superficial damage result in a detectable change in the reflected signal relative to reflection on an undamaged surface. As a result, in particular scratches and similar damage can be detected.

2 shows a schematic representation of another embodiment of the device. The scanning device 12 includes at least one transmitter 18 , which sends a signal in the direction of the material surface 10 sends out (the dashed line). The recording device 14 is located on the other side of the material surface and also beyond the material (eg, on the other side of the disk to be tested) so that the signal passes through the material before it hits the detector 20 the receiving device 14 meets. The evaluation device 16 is not shown in the figure. In this arrangement, not only the surface but also the material itself is tested. The signal passes through the material surface and also to the material itself. As a result, change in the radiation is measured by the passage through the material. In this way, the transmission, but also other optical changes (frequency shift, polarization) can be measured (also depending on the signal used for the measurement). This arrangement therefore allows a statement about the transparency of the disc.

3 shows a schematic representation of another embodiment of the device. The scanning device 12 includes at least one transmitter 18 , which sends a signal in the direction of the material surface 10 sends out (the dashed line). On the other side of the material is a reflector 30 arranged, which reflects the emitted signal. The detector 20 the receiving device 14 So picks up a signal that has passed twice through the material. The evaluation device 16 does not have to be part of the recording device 14 be. In this arrangement, it may also be partly due to a reflection similar to that in FIG 1 come, which can also be part of the evaluation. By this arrangement, it is possible that the receiving device and the scanning device can be accommodated in a common housing. This allows a more compact design because z. B. only one power supply is needed. At the same time, however, the transparency of the material can be similar to that in 2 be measured.

4 shows a schematic representation of an embodiment of the device in which the device is designed as a gun. The device comprises at least one transmitter 18 and / or detector 20 , wherein the illustrated variant comprises both. There is also a handle 34 for better handling and a trigger 32 present, to initiate the measurement.

Numerous modifications and developments of the described embodiments can be realized.

LIST OF REFERENCE NUMBERS

10

material surface

12

scanning

14

recording device

16

evaluation

18

Transmitter (electromagnetic signal)

20

Detector (electromagnetic signal)

30

reflector

32

trigger

34

Handle

quoted literature

cited patent literature

• DE 693 07 722 T2
• DE 2 261 460

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 69307722 T2 [0008]
• DE 2261460A [0009]

Claims (11)

Device for detecting the optical quality of a transparent material surface ( 10 ), in particular glass, characterized in that the device comprises at least one scanning device ( 12 ) for scanning the transparent material surface, at least one receiving device ( 14 ) for receiving an electromagnetic output signal and at least one with the scanning device ( 12 ) and / or recording device ( 14 ) associated evaluation device ( 16 ), wherein a) the scanning device ( 12 ) supplies the electromagnetic output signal, b) the receiving device ( 14 ) receives the electromagnetic output signal and c) the evaluation unit ( 16 ) Determines and displays standard deviations of the optical quality of the transparent material surface. Apparatus according to claim 1, characterized in that the scanning device ( 12 ) at least one transmitter ( 18 ) and / or at least one detector ( 20 ) of an electromagnetic signal. Device according to claim 2, characterized in that the transmitter ( 18 ) a light emitter, in particular a light emitting diode or a laser diode, and the detector ( 20 ) is a light detector, in particular a photosensitive resistor (LDR) or a photodiode. Device according to one of claims 2 or 3, characterized in that the at least one transmitter ( 18 ) and the at least one detector ( 20 ) are arranged in such a way that the detector ( 20 ) the electromagnetic signal of the associated transmitter ( 18 ) by reflection from the transparent material surface ( 10 ) itself and / or from a reflection means, preferably a mirror or foil. Apparatus according to claim 2, characterized in that the at least one detector ( 20 ) is arranged such that it receives the electromagnetic signal from an opposite side of the transparent material surface ( 10 ) attached transmitter receives. Device according to one of the preceding claims, characterized in that the evaluation device ( 16 ) has a digital display, which provides a numerical display for the determined standard deviation of the optical quality of the transparent material surface. Device according to one of the preceding claims, characterized in that the scanning device ( 12 ) a receiving device ( 14 ) and / or an evaluation device ( 16 ) having. Device according to one of the preceding claims, characterized in that the device, the scanning device ( 12 ), the receiving device ( 14 ) and / or the evaluation device ( 16 ) Has attachment means for releasable attachment to the transparent material surface, in particular disc. Apparatus according to claim 8, characterized in that it is the attachment means for releasable attachment to the transparent material surface, in particular disc, a suction cup or suction plate. Device according to one of the preceding claims, characterized in that the device is designed in the form of a laser gun. Use of a device according to one of claims 1 to 10 for the detection of the optical quality of a transparent material surface ( 10 ), especially glass.

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