DE102014223745A1 - Method and device for detecting emitted light and method of manufacture - Google Patents

Abstract

The invention relates to a method and a device for detecting emitted light (3) of a security document (3), wherein the device (1) comprises at least one light guide body (4), wherein the light guide (4) has at least one light channel (6) or wherein the light channel (6) has an inlet opening (7) and at least one first outlet opening (7), wherein the wall surface (s) (9, 9a, 9b) enclosing the light channel (6) is / are designed to be completely reflecting Light guide (4) is formed lens-free, and a method for its preparation.

Description

The invention relates to a device and a method for detecting light which is emitted by a security document, and to a method for producing such a device.

It is known to detect light by means of an optical system which is emitted, transmitted, reflected or scattered from a surface of a security document. Depending on the properties of the light detected in this way, in particular an authenticity check can be carried out.

Optical systems which are used for detecting the radiated light regularly consist of a plurality of lenses which image the surface or a subregion of the surface of the security document into a detector plane of an optical sensor.

Since the light intensity, ie the amount of light per detector surface, square with the measuring distance, the z. Example, a distance between an entrance surface of the optical system and surface to be imaged decreases, are used for low-luminance surfaces optical systems with a large aperture and a small measurement distance to capture as much light. Here, the aperture designates a diameter of an inlet opening of the optical system, in particular the diameter of an entrance lens. The entrance surface may be equal to the detector surface, in particular when light from the surface directly, so without radiating through further optical element, strikes the detector.

The larger the lens and the smaller the measuring distance, the larger the solid angle from which light can be picked up. However, small measuring distances, in particular measuring distances which are smaller than a focal length of an entrance lens of the optical system, due to the beam divergence to light losses in the system, the light z. B. can be absorbed by the housing.

Also, such systems result in increased dependence of the measurement result on both the measurement distance and a position of the security document relative to an optical axis of the optical system. Thus, the use of such an optical system may require a high positioning accuracy.

Furthermore, each lens of the optical system causes low reflections and thus light losses. Another disadvantage is the high construction costs and the high space requirement of these optical systems with lenses.

The technical problem is to provide a device and a method for detecting emitted light of a security document and a method for producing such a device, which allow detection of a desired amount of light, but at the same time a space requirement, weight, construction costs and light losses and positioning sensitivity reduce.

The solution of the technical problem results from the objects with the features of claims 1, 15 and 16. Further advantageous embodiments of the invention will become apparent from the dependent claims.

It is a basic idea of the invention to make a device for detecting light which is emitted by a security document lens-free.

Proposed is a device for detecting emitted light of a security document. In this case, the light is emitted from the security document, in particular from the surface of the security document. The emitted light may denote diffused light, reflected light, transmitted light or emitted light.

A security document may be any document that is a physical entity that is protected against unauthorized creation and / or falsification by security features or elements. Security features are features that make it difficult to falsify and / or duplicate compared to a simple copy at least. Physical entities that include or form a security feature may be referred to as security features. A security document may include multiple security features and / or security elements. As defined herein, a security document can always be a security element. Examples of security documents, which also include value documents representing a value, include, for example, passports, identity cards, driving licenses, identity cards, access control cards, health insurance cards, banknotes, postage stamps, bank cards, credit cards, smart cards, tickets and labels.

In this case, the security document can contain or have, in particular, light-scattering, photoluminescent / phosphorescent elements or electroluminescent elements, in particular pigments. These enable authenticity verification as a function of emitted photo- or electroluminescent radiation, if such Luminous element, z. B. by light and / or an electric field is excited. In such a case, however, it is not absolutely necessary for the authenticity verification to make an optical image of a subarea of the surface, but only to detect the amount of emitted light.

In this case, the device may in particular be part of a device for checking the authenticity of the security document. Such a device makes it possible to verify the authenticity of the security document, in particular by evaluating properties of the emitted light.

The device comprises at least one light guide body. As explained in more detail below, the light-guiding body may be formed as a coated glass body or comprise such. Alternatively, the light guide as a solid profile with at least one, z. B. filled with air or another transparent material filled, Lichtleitkanal be formed.

The light guide body has at least one light channel or forms such. The light channel has an inlet opening and at least one first outlet opening. The inlet opening and the first outlet opening are thus connected by the light channel. The inlet opening here denotes an opening through which the light emitted by the security document enters the light channel. The outlet opening accordingly designates an opening through which the light which has entered and is radiated through the light channel can exit or exit the light channel.

Next, the light channel enclosing wall surface or enclosing wall surfaces are formed completely reflective. This means that no light can escape from the light channel through the wall surface (s). For example, the wall surface (s) can be designed to be mirror-like.

According to the light guide body is formed lens-free. This means that the light guide body does not comprise a lens or an optically equivalent element. In particular, the light guide body does not comprise a lens or optically equivalent element which serves for optical imaging and / or light bundling.

Thus, the feature that the light guide is formed lens-free, mean that the light channel is formed such that a direction of the light entering through the inlet opening into the light channel is changed only by reflection on the wall surfaces. Alternatively or cumulatively, the feature that the light guide body is formed lens-free, mean that a refraction, beam focusing and / or beam scattering of the light entering through the inlet opening into the light channel takes place exclusively by reflection on the wall surfaces. Thus, it is not possible to arrange an optical element for changing the beam direction of the light, for beam refraction, for beam focusing and / or for beam scattering in and / or along the light channel.

The property that the light guide is formed lens-free, but does not necessarily exclude that one or more optical elements, eg. B. mirror or beam splitter, are covered by the light guide. However, such optical elements do not serve for light bundling and / or optical imaging.

In particular, the inlet opening and / or the first outlet opening can / can be formed lens-free. This means that no change in the beam direction of the light, no refraction, no beam focusing and / or no beam scattering, in particular by an optical element takes place at the inlet and / or the outlet opening.

Thus, the light channel can be in direct optical communication with an environment via the inlet opening. This may mean that light can radiate into the light channel without changing properties from the environment. Furthermore, the light channel via the outlet opening can be in direct optical connection with an environment or with an optical sensor explained in more detail below. This may mean that light can radiate out of the light channel into the environment or onto the optical sensor without changing properties.

In other words, the light guide body can be formed without imaging elements, the light guide body not comprising an element for optical imaging. However, this does not rule out that a beam guide for detecting light is performed by the light guide body.

This results in an advantageous manner that collected from the surface of the security document light collected and through the light channel z. B. can be passed to an optical sensor. Subsequently, properties of the light detected by the optical sensor can be determined and evaluated. In order to determine these properties, no optical imaging of the surface or a subarea thereof is required. In particular, optical imaging is not required if only the amount or intensity of the light emitted from areas of the surface of the security document is to be detected.

The proposed device advantageously enables loss-free detection of the radiated light, wherein construction costs and a space requirement due to the unnecessary lenses are minimized.

In a further embodiment, the device comprises at least one optical sensor, wherein the optical sensor is arranged in or at the first outlet opening. The optical sensor can in this case comprise or have an active surface, wherein the optical sensor can generate an output signal as a function of the light radiating or incident on this active surface.

The arrangement of the optical sensor at or in the first outlet opening may mean that the light passed through the light channel to the first outlet opening and / or the light emerging from the first outlet opening is completely or at least to a predetermined proportion, for. B. at least 90%, radiates or falls on the active surface.

The active surface may in this case have a predetermined geometry and / or predetermined dimensions. In this case, a geometry of the outlet opening and / or dimensions of the outlet opening may correspond to the geometry or dimension of the active area.

Thus, the active surface may be arranged at the outlet opening also within the light channel. This can be z. B. mean that the light channel encloses the active surface of the optical sensor at its outlet opening. In this case, no or a predetermined (small) distance may be present between the wall surface of the light channel and the active surface. If there is no distance, then the wall surface of the light channel can be arranged at the first outlet opening flush with edges of the active surface. Thus, the light channel can be in direct optical communication with the active surface of the optical sensor via the exit opening. In this case, it may be possible that no light exits the first outlet opening into an environment. However, the optical sensor, in particular its active surface, can also be arranged outside the first outlet opening.

Overall, however, results in an advantageous manner that reduce the light losses.

In a further embodiment, the light channel has at least one branching into a first sub-channel with the first outlet opening and at least one further sub-channel with a further outlet opening. For example, the light channel may comprise a main channel section between the inlet opening and the branch. Furthermore, the light channel may comprise a first part-channel section between the branch and the first outlet opening. Accordingly, the light channel may comprise a further partial channel section between the branch and the further outlet opening. Of course, the light channel, in particular at least one of the sub-channels or the main channel section, have a further branch.

This results in an advantageous manner that radiated light into the light channel can be spatially divided to, as explained in more detail below, a spatially separate detection of the light, z. B. by a plurality of spatially separated optical sensors to allow.

In a further embodiment, the device comprises a beam splitter, which distributes light, in particular from the main channel section, in a predetermined ratio to the first sub-channel and the at least one further sub-channel, for. B. in this deflects or irradiates. The beam splitter may be located at / in front of the branch. For example, the beam splitter can direct light from a main channel section of the light channel in a predetermined ratio into the first sub-channel and into the at least one further sub-channel.

The predetermined ratio may be a light amount ratio or a light intensity ratio. The ratio can be determined as a function of the light properties to be detected and / or the sensitivity of optical sensors at the outlet openings of the sub-channels. Preferably, the predetermined ratio may be 1: 1. Of course, however, other conditions are conceivable.

In this case, the beam splitter denotes an optical element, by means of which a beam direction of at least part of the light radiated onto the beam splitter is changed. In particular, a beam direction of a first portion of this light can not be changed by the beam splitter, wherein a beam direction of the remaining portion is changed by the beam splitter. Of course, however, beam directions of both components can be changed.

This results in an advantageous manner as reliable as possible division of the light for transmission in different sub-channels.

In an alternative embodiment, the branching is designed such that the light at the branch, in particular the light from the main channel section, is split in a predetermined ratio onto the first and the at least one further sub-channel. For example, can the branching be formed such that the light from a main portion of the light channel radiates in a predetermined ratio in the first sub-channel and in the at least one further sub-channel. This results in an advantageous manner a beam splitter-free distribution of the light. The predetermined ratio may in turn denote a light quantity or light intensity ratio. Preferably, the ratio is 1: 1. Of course, however, other conditions are conceivable. For example, the branching can be provided by a suitable design and / or a suitable geometric profile of the wall surface (s).

This results in an advantageous manner, a simple provision of the light branching.

In a further embodiment, the device comprises at least one further optical sensor, wherein the at least one further optical sensor is arranged in or at the first outlet opening or in or at the at least one further outlet opening.

Thus, in a first alternative, the first and the further optical sensor can be arranged in or at the first outlet opening. In this case, the two optical sensors can be used to detect and optionally determine mutually different properties of the light.

For example, the first and the further optical sensor may be arranged spatially adjacent to one another in or at the first outlet opening.

The arrangement of the optical sensors at or in the first outlet opening may mean that the light guided through the light channel to the first outlet opening and / or the light emerging from the first outlet opening is completely or at least to a predetermined proportion, for. B. at least 90%, on the totality of the active surfaces radiates or falls.

The active surfaces can be arranged inside or outside the light channel. Preferably, no or only a predetermined (small) distance between edges of the active surfaces of the two sensors may be present. The active surfaces may be arranged such that the light directed towards the first outlet opening radiates in a predetermined ratio, in particular in equal or unequal parts, to the active surfaces.

As already explained above, a geometry of the outlet opening and / or dimensions of the outlet opening may also correspond in this case to the geometry or dimension of the active surfaces, for example an envelope of the active surfaces. This can mean that the light channel encloses the active surfaces of the optical sensors at its first outlet opening. In this case, no or a predetermined (small) distance may be present between the wall surface of the light channel and the active surfaces. If there is no distance, then the wall surface of the light channel can be arranged flush with the active surfaces at the first outlet opening. Thus, the light channel may be in direct optical communication with the active surfaces of the optical sensors via the exit aperture.

In the second alternative, the further optical sensor is arranged spatially separated from the first optical sensor. This advantageously reduces mutual influence on the optical sensors, which can adversely affect the output signal of the sensors.

According to the statements on the arrangement of the first optical sensor at or in the first outlet opening, the further optical sensor can be arranged on or in the further outlet opening such that the light guided through the light channel to the further outlet opening and / or the outlet emerging from the further outlet opening Light completely or at least to a predetermined proportion, z. B. at least 90%, radiates or falls on the active surface of the other optical sensor.

The further optical sensor can be arranged inside or outside of the further sub-channel. Furthermore, a geometry and / or dimension of the further outlet opening can be adapted to the geometry and / or dimension of the active surface of the further optical sensor. Reference is made to the corresponding previous statements.

In a further embodiment, the first optical sensor is a spectral sensor and the at least one further sensor is a light quantity sensor. This results in an advantageous manner that mutually different properties of the light are detected by mutually different sensors. This results in an advantageous way a more accurate detection and determination of these properties.

In a further embodiment, the light channel is designed as a free-form body. In particular, a design of the free-form body, in particular the formation of the inlet and outlet opening, depending on a geometry and position of a radiating surface and in dependence on a geometry of an active surface of a optical sensor can be selected. In particular, the inlet opening can be adapted to any geometry and / or position of the radiating surface and the outlet opening to the geometry of the active surface of a sensor. In particular, a shape and / or a surface of the inlet opening may be different from the shape or area of the outlet opening. For example, an inlet opening may be rectangular and an outlet opening may be circular. Thus, z. For example, beams from a radiating strip of the security document can be directed onto a circular active area without much loss of light, in particular by multiple reflection.

In a further embodiment, a cross section of the light channel decreases from the inlet opening towards the at least one outlet opening. The cross section may in this case designate a cross-sectional area or a, in particular maximum, diameter of the light channel. Alternatively, the cross section of the light channel increases from the inlet opening towards the at least one outlet opening. However, it is not excluded that the light channel has sections with a constant cross section. A size of the cross section may, for example, be detected along a central axis of the light channel. Along the light channel, the cross-section z. B. non-continuous, in particular jump, steady or differentiable change. In particular, a cross section of the inlet opening may be larger or smaller than a cross section of the at least one outlet opening. This advantageously results in a desired concentration or a desired distribution of the light irradiated into the light channel.

In a preferred embodiment, at least a portion of the light channel, in particular the entire light channel, frusto-conical or truncated pyramid shaped. Alternatively or cumulatively, at least one subsection of the at least one subchannel, in particular the entire subchannel, may be frusto-conical or truncated pyramidal. This does not exclude that at least one further subsection of the light channel and / or the at least one subchannel is cylindrical or cuboidal. This results in an advantageous manner as simple as possible mechanical production of the light guide body.

In a further preferred embodiment, the light channel is designed such that a back reflection-free propagation of the light from the inlet opening to the at least one outlet opening takes place.

This may mean that a direction of the light introduced through the inlet opening in the light channel is only changed in such a way that the beam direction in each section of the light channel comprises a portion which is oriented parallel to a center line or central axis of the light channel and in the direction of the outlet opening, is oriented in particular from the inlet opening to the outlet opening. However, it is not excluded that the beam direction has a further portion transverse to this center line or central axis. However, it is essential that the beam direction has no or an only negligible proportion in a direction which is oriented parallel to the center line or central axis and in the direction of the inlet opening.

In a further embodiment, a wall surface inclination and / or a length of the light channel and / or at least one subchannel is / are selected such that the back reflection-free propagation is ensured as a function of a dimension of the inlet opening and a dimension of the outlet opening. In this case, the inlet and outlet opening designates the inlet opening of the respective channel section, that is to say, for example, of the previously explained main channel section or partial channel section.

In this case, the dimension of the inlet opening can be determined as a function of a dimension of the surface of the security document to be detected and / or a desired or necessary distance of the inlet opening from this surface and a desired angle of incidence of the light emitted by the surface to be detected on the inlet opening. The angle of incidence may in this case be an angle relative to a line which is oriented perpendicular to the inlet opening, in particular an angle relative to an optical axis of the inlet opening.

The dimension of the outlet opening may be dependent on the dimension of the active surface of the optical sensor. In particular, the dimension of the exit opening may correspond to the dimension of the active area or be greater than the dimension of the active area by a predetermined (small) amount.

The wall surface slope may be given relative to a central axis or centerline of the light channel. If the (sub) channel has a curvature or a kink, the wall surface inclination can be given relative to a tangent to the central axis or center line. However, it is also possible that in this case the wall surface inclination is given relative to the optical axis of the inlet opening of the light channel or an inlet opening of a sub-channel. The center line of the inlet opening here denotes a line oriented perpendicular to an inlet surface, which intersects the inlet surface at its geometric center.

The wall surface slope may vary along the light channel, especially within a predetermined pitch interval. This may mean that the wall surface inclination along the light channel and / or the at least one sub-channel is greater than or equal to a predetermined minimum inclination and / or less than or equal to a maximum inclination. In this case, the wall surface inclination may change non-steadily along the light channel, in particular in a sudden, continuous or preferably differentiable manner. In particular, the inclination may be given by an angle between the central axis and a line of intersection through the wall surface, the section line lying in a sectional plane spanned from the central axis and a vector perpendicular to the central axis or center line with the vector oriented from the central axis or midline towards the wall surface. In particular, in this case, the angle may be given by the angle between the central axis and a tangent to the intersecting line in the intersection of the intersecting line with the vector.

Depending on the geometric configuration of the light channel, the beam direction of the light irradiated into the light channel, in particular in the case of multiple reflection, can change such that along the light channel the component oriented parallel to the center line or central axis of the light channel and in the direction of the outlet opening decreases. Thus, the wall surface inclination and the length of the light channel can in particular be selected such that this proportion is greater than zero along the light channel in each section.

In a further embodiment, the wall surface inclination changes along the light channel and / or along at least one subchannel. This advantageously results in a further minimization of light losses.

In a further embodiment, the light channel is formed by a translucent material. The propagation of the light in the light channel takes place here within the body. In particular, the light channel can be formed by a glass or plastic body. Here, the glass or plastic body may be coated, being provided by the coating completely reflecting wall surfaces of the glass or plastic body. Alternatively, there is air in the light channel.

This advantageously allows a simple production of the light channel with the desired properties.

Further proposed is a method for producing a device for detecting emitted light of a security document. In this case, at least one light guide body is provided, wherein at least one light channel is provided in the light guide body. The light channel has an inlet opening and at least one outlet opening, whereby the wall surface / s enclosing the light channel is / are formed to be completely reflecting.

According to the light guide body is formed lens-free.

The method advantageously makes it possible to produce a device for detecting emitted light according to one of the previously explained embodiments. In particular, the method can thus comprise all the method steps which are necessary for producing a device according to one of the previously explained embodiments.

Further proposed is a method for detecting emitted light, in particular an amount of intensity, of a security document, wherein a device according to one of the above-explained embodiments is arranged relative to a surface of the security document such that light emitted from at least a portion of the surface passes through the Inlet opening enters the light channel.

This results in an advantageous manner detection of emitted light, which does not require a cost-intensive and space-consuming device.

The invention will be explained in more detail with reference to several embodiments. The figures show:

1 a schematic cross section through a device according to the invention,

2 a schematic longitudinal section through a light channel,

3 a schematic longitudinal section through a light channel in a further embodiment,

4 a schematic cross section through a device according to the invention in a further embodiment,

5 a perspective view of a device according to the invention in a further embodiment and

6 a schematic cross section through a device according to the invention in a further embodiment.

In 1 is a schematic cross section through a device 1 for detecting radiated light 2 , which is exemplified by arrows, a security document 3 shown. The device 1 includes a light guide body 4 and an optical sensor 5 , which may be formed, for example, as a photodetector, in particular as a CCD sensor or CMOS sensor. The light guide body 4 has a light channel 6 on. The light channel 6 has an inlet opening 7 and an exit opening 8th on. Here it is shown that the radiated light 2 through the entrance opening 7 in the light channel 6 enters and along the light channel 6 of wall surfaces 9 of the light channel 6 is reflected and thus to the outlet opening 8th is blasted. That through the outlet opening 8th leaking light 2 shines on an active surface 10 of the optical sensor 5 , The optical sensor 5 is here at the outlet opening 8th arranged.

The wall surfaces 9 of the light channel 6 are formed completely reflective. Thus, light enters 2 from the light channel 6 exclusively via the outlet 8th from the light channel 6 out.

It is further shown that the light guide 4 , especially the light channel 6 , is formed lens-free. In particular, no lens for beam focusing, refraction or beam steering in or at the inlet opening 7 , in or at the light channel 6 or in or at the exit opening 8th intended.

In 1 is shown that the light channel 6 is frusto-conical. This reduces a diameter of the light channel 6 from the entrance opening 7 towards the outlet 8th ,

Furthermore, it is shown by way of example that a back reflection-free propagation of the light 2 from the entrance opening 7 to the exit opening 8th he follows. By a dashed line is a central axis z of the light channel 6 shown, which is orthogonal to a surface of the inlet opening 7 is oriented and from the entrance opening 7 to the outlet 8th is oriented. In 1 is shown that light rays 2 before and after a reflection on the wall surface 10 of the light channel 6 in each section of the light channel 6 have a portion which is parallel to the central axis z and towards the outlet opening 8th is oriented. In particular, the direction includes before or after reflection of the light rays 2 no portion parallel to the optical axis z towards the inlet opening 7 is oriented.

In 2 is a light channel 6 in a first embodiment shown in a longitudinal section. In the in 2 illustrated embodiment, the light channel 6 be formed, for example, truncated pyramid. Shown is that a first wall surface 9a or a first wall surface section parallel to the central axis z of the light channel 6 is oriented.

In the in 2 illustrated embodiment corresponds to the central axis z of the light channel 6 again a center line of the inlet 7 perpendicular to the surface of the inlet 7 is oriented and cuts them in a geometric center. The central axis z runs along the light channel 6 not in the middle of the light channel 6 ,

The first wall surface 9a is therefore not inclined. Also shown is a second wall surface 9b or a second wall surface portion, which is inclined relative to the central axis z, in particular with an inclination angle β.

In 2 E denotes a diameter or a width of the inlet opening 7 , Further, D denotes a diameter or a width of the outlet opening 8th , L _OB denotes a desired or necessary distance of the inlet opening 7 from the surface of the security document to be captured 3 along the central axis z. Also shown is a length L _{M of} the light channel 6 along the central axis z.

By the reference character α is hereby exemplarily a minimum angle of incidence of the light 2 on the first wall surface 9a designated. The angle γ denotes a detection angle.

Also shown is an exemplary course of a light beam 2 , with the minimum angle of incidence α on the first wall surface 9a at the entrance 7 incident. This ray of light 2 will be on the first wall surface 9a with the angle of incidence, so the angle α, reflected and towards the second wall surface 9b blasted. The beam path of the light beam 2 is shown here for several reflections, it being apparent that the angle of incidence and reflection in a reflection on the wall surfaces 9a . 9b along the light channel 6 decreases.

For the in 2 illustrated embodiment, the following relationships apply: tanβ = (E - D) / L _M Formula 1 and tan α = (2 × L _OB ) / E Formula 2 and α ≥ (N + 1) × β Formula 3 ,

Where N is the number of reflections.

The length L _M and / or the size of the inlet opening E and / or the inclination angle β can be adjustable parameters in the production of the light guide 4 be. By Formula 1 is the relationship between the inclination angle β, the length of light channel L _M and the size of the entry and exit opening E, D given. These parameters can for example be determined such that the through inlet 7 entering light rays without back reflection in the direction of the inlet opening 7 through the light channel 6 be blasted. For example, depending on this relationship, a maximum number of reflections can be determined, that through the inlet opening 7 can pass through incoming light rays without going back in the direction of the inlet opening 7 to be reflected. Thus, they determine the minimum angle of incidence for a beam, which after multiple reflection, the outlet opening 8th can reach. In 2 It is shown that for a beam with angle of incidence α after a third reflection from the second wall surface 9b a back reflection in the direction of the inlet opening 7 he follows.

In 3 is an exemplary longitudinal section through a light channel 6 shown in a further embodiment. Unlike the in 2 illustrated embodiment is in this case, the first wall surface 9a or the first wall surface portion inclined relative to the central axis z with the inclination angle β. In this embodiment, the following relationships apply: tanβ = (E - D) / 2 x L _M Formula 4 and tan γ = (E - D) / (2 × L _OB ) Formula 5 and α = 90 - γ - β Formula 6.

In 4 is a schematic cross section through a device according to the invention 1 shown in a further embodiment. Unlike the in 1 illustrated embodiment, the light channel 6 a branch of the light channel 6 into a first subchannel 11a and into a second subchannel 11b on. The first subchannel 11a here has the first outlet opening 8th on, with the second subchannel 11b another outlet 12 having. The device 1 further includes another optical sensor 13 with an active area 14 the other optical sensor 13 , Also shown is a beam splitter 15 , the light from a main channel section 16 of the light channel 6 in a predetermined ratio in the first subchannel 11a (first sub-channel section) and in the second sub-channel 11b (second sub-channel section) irradiates.

The other optical sensor 13 is at the other outlet opening 12 arranged, wherein from the further outlet opening 12 leaking light 2 on the active surface 14 the other optical sensor 13 falls.

The optical sensors 5 . 13 can capture different properties of light 2 serve. Also, the optical sensors can 5 . 13 with different optical elements, for example different optical filters, are combined, e.g. B. with different color filters. In particular, in this case, the optical sensors 5 . 13 for detecting different properties of the light 2 serve.

For example, the optical sensor 5 be formed as a photodetector or as a combined with a spectral filter photodetector. The other optical sensor 13 can be configured for example as a color sensor or spectral sensor. Also, the other optical sensor 13 be designed as a CCD sensor.

So z. B. by the first optical sensor 5 a temporal course of the light intensity are detected, wherein by the further optical sensor 13 a spectral composition, for example a color, of the light 2 is determined.

Next is in 4 a central axis z _{1 of} the first subchannel 11a represented, the central axis z of the main channel section 16 of the light channel 6 corresponds, wherein the central axis of the main channel section 16 a centerline of the entrance opening 7 equivalent. Also shown is an inlet opening 18 of the first subchannel 11a , wherein the central axis z _{1 of} a center line of the inlet opening 18 of the first subchannel 11a equivalent. Wall surfaces of the first subchannel 11a are here with respect to the central axis z _{1 of} the first subchannel 11a inclined.

Next is a central axis z _{2 of} the second subchannel 11b shown. The further central axis z ₂ is in this case orthogonal to an inlet opening 17 of the second subchannel 11b oriented and intersects surface of the further inlet opening 17 in its geometric center. Wall surfaces of the second subchannel 11b are in this case with respect to the central axis z _{2 of} the further subchannel 11b inclined. Here, the central axis z _{2 of} the second subchannel 11b with respect to the central axis z _{1 of} the first part of the channel section 11a inclined.

In 5 is a perspective view of a device 1 in a further embodiment shown. Here it is shown that the light channel 6 is formed truncated pyramid. It is further shown that in the outlet opening 8th of the light channel 6 both the first optical sensor 5 as well as the other optical sensor 13 are arranged side by side. One dimension of the outlet 8th is here on a dimension and geometry of the overall arrangement of the first optical sensor 5 and the other optical sensor 13 customized. In particular, encloses the outlet opening 8th the rectangular envelope of the active surfaces 10 . 14 (please refer 4 ) of the two sensors 5 . 13 ,

As before with respect to 4 already explained, the optical sensors 5 . 13 for detecting different properties of light 2 be formed or be combined with each other different optical elements, in particular filter elements.

At the in 5 illustrated arrangement of the first and the further optical sensor 5 . 13 are active surfaces 10 . 14 (please refer 4 ) of the optical sensors 5 . 13 arranged in a plane next to each other. As a result, the light front of the incident on the active surfaces of light 2 be divided into channels. However, there is no division of the light amplitude. Upon detection, determination and evaluation of properties of the light detected in this way, however, homogeneity of the light distribution in the plane of the active surfaces can be taken into account.

Generally, a geometry of the light channel 6 and thus a formation and / or arrangement of the wall surface (s) 9 . 9a . 9b be chosen freely. Ideally, however, the shape and arrangement will conform to a geometry and / or dimension of the active area 10 . 14 an optical sensor 5 . 13 customized. Also, the training and / or arrangement can be chosen such that no back reflection in the light channel 6 he follows.

In 6 is a schematic cross section through a device 1 shown in a further embodiment. Here it is shown that the light channel 6 at a branch into a first sub-channel 11a and a second subchannel 11b branched. The branching is in this case by the formation of the light channel 6 , in particular achieved by a corresponding wall surface course. The branching is in this case designed such that light 2 from a main channel section 16 of the light channel 6 in a predetermined ratio in the first subchannel 11a and the second subchannel 11b irradiates. Shown is an entrance opening 17 of the second subchannel 11b and an entrance opening 18 of the first subchannel 11a , Also shown are central axes z ₁ , z _{2 of} the first subchannel 11a and the second subchannel 11b , Here it is shown that the central axes z ₁ , z _{2 of} the subchannels 11a . 11b opposite the central axis z of the main section 16 are each inclined.

It is further shown that a wall surface inclination of a wall surface of the first subchannel 11a and a wall surface of the second sub-channel 11b along the first or second subchannel 11a . 11b changes. The wall surfaces of the first and the second subchannel 11a . 11b are each formed curved. As for 4 already explained, is the first optical sensor 5 at the first outlet 8th arranged, wherein the second optical sensor 13 at the other outlet opening 12 is arranged.

The proposed device 1 offers several advantages. On the one hand, light losses are reduced because there are no lenses in the device 1 be used. Is the outlet opening 8th . 12 to the respective optical sensor 5 . 13 adapted, so also light losses can be minimized, especially if the active area 10 . 14 of the respective sensor 5 . 13 the corresponding outlet opening 8th . 12 completely fills or covers.

Next is the proposed device 1 compared to the lens-based embodiment less sensitive to a lateral positional deviation of the radiation source to be measured (eg the emitting, reflecting and / or scattering surface of the security document 3 ), wherein the lateral position deviation is a deviation perpendicular to the center line of the inlet opening 7 designated. Also, the proposed device 1 less sensitive to inclination of the surface of the security document 3 relative to this midline. This means that towards the at least one outlet opening 8th . 12 Directed amount of light is not or only to a small extent dependent on the lateral position deviation and / or inclination. Next, the inlet opening 7 , in particular its geometry and / or dimension to a geometry and / or dimension of a security feature of the security document 3 be adjusted. Next, the cost and weight of the device 1 be reduced. Due to the high light efficiency can continue to cheaper optical sensors 5 . 13 can be used, which are also flexible in their shape selectable. Also results in a simple adjustment and maintenance.

LIST OF REFERENCE NUMBERS

1

contraption

2

beam of light

3

The security document

4

fiber-optic element

5

first optical sensor

6

Lichtkanal

7

inlet opening

8th

outlet opening

9

wall surface

9a

first wall surface

9b

another wall surface

10

active area

11a

first subchannel

11b

second subchannel

12

further outlet opening

13

additional optical sensor

14

active area

15

beamsplitter

16

Main channel portion

17

Inlet opening of the second sub-channel

18

Inlet opening of the first sub-channel

z

central axis of the light channel / main section

z ₁

central axis of the first subchannel

z ₂

central axis of the further subchannel

e

Diameter / width of the inlet opening

D

Diameter / width of the outlet opening

β

tilt angle

α

minimal angle of incidence

γ

angle of coverage

L _OB

Distance between the inlet and the surface to be measured

L _M

Length of the light channel

Claims (16)

Device for detecting emitted light ( 3 ) of a security document ( 3 ), the device ( 1 ) at least one light guide body ( 4 ), wherein the light guide body ( 4 ) at least one light channel ( 6 ) or forms, wherein the light channel ( 6 ) an entrance opening ( 7 ) and at least one first outlet opening ( 8th ), wherein the light channel ( 6 ) enclosing wall surface (s) ( 9 . 9a . 9b ) Is fully reflective / are characterized in that the light guide ( 4 ) is formed lens-free. Device according to claim 1, characterized in that the device ( 1 ) at least one optical sensor ( 5 ), wherein the optical sensor ( 5 ) in or at the first exit opening ( 8th ) is arranged. Apparatus according to claim 1 or 2, characterized in that the light channel ( 6 ) at least one branch into a first subchannel ( 11a ) with the first outlet opening ( 8th ) and in at least one further subchannel ( 11b ) with a further outlet opening ( 12 ) having. Device according to claim 3, characterized in that the device ( 1 ) a beam splitter ( 15 ), the light ( 2 ) in a predetermined ratio to the first sub-channel ( 11a ) and the at least one further subchannel ( 11b ). Apparatus according to claim 3, characterized in that the branch is formed such that the light ( 2 ) in a predetermined ratio to the first sub-channel ( 11a ) and the at least one further subchannel ( 11b ) is divided. Device according to one of claims 2 to 5, characterized in that the device at least one further optical sensor ( 13 ), wherein the at least one further optical sensor ( 13 ) in or at the first exit opening ( 8th ) or in or at the at least one further outlet opening ( 12 ) is arranged. Apparatus according to claim 6, characterized in that the first optical sensor ( 5 ) a spectral sensor and the at least one further sensor ( 13 ) is a light quantity sensor. Device according to one of claims 1 to 7, characterized in that the light channel ( 6 ) is designed as a freeform body. Device according to one of claims 1 to 8, characterized in that a cross section of the light channel ( 6 ) from the entrance opening ( 7 ) to the at least one outlet opening ( 8th ) or the cross section of the light channel ( 6 ) from the entrance opening ( 7 ) to the at least one outlet opening ( 8th ). Device according to one of claims 1 to 9, characterized in that at least a portion of the light channel ( 6 ) and / or at least a subsection of the at least one subchannel ( 11a . 11b ) is frusto-conical or truncated pyramid shaped. Device according to one of claims 1 to 10, characterized in that the light channel ( 6 ) is designed such that a return-free propagation of the light ( 2 ) from the entrance opening ( 7 ) to the at least one outlet opening ( 8th ) he follows. Apparatus according to claim 11, characterized in that a wall surface inclination and / or a length (L _M ) of the light channel ( 6 ) and / or at least one sub-channel ( 11a . 11b ) depending on a dimension of the inlet opening ( 7 . 17 . 18 ) and a dimension of the outlet opening ( 8th . 12 ) is / are selected such that the return-reflection-free propagation is ensured. Apparatus according to claim 12, characterized in that a wall surface inclination along the light channel ( 6 ) and / or at least one sub-channel ( 11a . 11b ) changes. Device according to one of claims 1 to 13, characterized in that the light channel ( 6 ) is formed by a translucent material or in the light channel ( 6 ) Air is located. Method for producing a device ( 1 ) for detecting radiated light ( 2 ) of a security document ( 3 ), wherein at least one light guide body ( 4 ), wherein at least one light channel ( 6 ) in the light guide body ( 4 ), wherein the light channel ( 6 ) an entrance opening ( 7 ) and at least one first outlet opening ( 8th ), wherein the light channel ( 6 ) enclosing wall surface (s) ( 9 . 9a . 9b ) is / are formed completely reflecting, characterized in that the light guide body ( 4 ) is formed lens-free. Method for detecting emitted light ( 2 ) of a security document ( 3 ), wherein a device ( 1 ) according to one of claims 1 to 14 in such a way relative to a surface of the security document ( 3 ) is arranged that of at least a portion of the surface radiated light ( 2 ) through the inlet opening ( 7 ) in the light channel ( 6 ) entry.

Images