Sensor device for detecting deposits on glass sheets

Abstract

The invention relates to a sensor device for detecting deposits on a glass sheet. The invention relates to a sensor device for detecting deposits, in particular water deposits, such as moisture deposits and / or ice deposits, on a glass pane, in particular on the inner side of a vehicle glass pane, comprising a radiation emitter for irradiating the glass pane and a radiation receiver for detecting the radiation intensity of radiation reflected by the glass pane, at least one optical body having at least one radiation-conducting element is assigned to the radiation emitter and / or the radiation receiver, according to the invention, the radiation-conducting element has at least two segments, each segment having at least one refractive surface, and the refractive surfaces are arranged towards the radiation emitter and / or the radiation receiver.

Description

Technical Field

[0001] The invention relates to a sensor device for detecting deposits, in particular water deposits, such as moisture deposits and / or ice deposits, on the inner side of a glass pane, in particular a vehicle glass pane, having a radiation transmitter for irradiating the glass pane and a radiation receiver for detecting the radiation intensity of radiation reflected by the glass pane, wherein the radiation receiver is designed to detect the scattered radiation intensity of radiation scattered at the glass pane, and wherein at least one optical body having at least one radiation-conducting element is associated with the radiation transmitter and / or the radiation receiver. Background Art

[0002] When driving a vehicle safely, it may be very important to detect deposits such as pollutants or water deposits, such as water vapor, ice deposits or even frost. The formation of deposits may affect the driver's vision on the one hand, and may also interfere with the function of the display projected on the inner side of the windshield, the so-called head-up display, on the other hand. As a result, the driver cannot correctly visually recognize information related to the driver, such as the fuel gauge, the charge state of the battery, sign recognition, the current driving speed, etc. The icy, hoarfrost-moistened, fogged or contaminated windshield plate causes distortion of the projected information. This may cause the driver to be unable to obtain or to misinterpret the required information necessary for safely participating in road traffic. When frost, ice or water vapor is formed on the inner side of the windshield plate, the driver must be notified accordingly or the control of the head-up display must be adapted. For this reason, it is necessary to recognize the mentioned deposits in advance. A sensor device for identifying the water vapor state is known, for example, from DE 10 2006 039 034 A1.

[0003] Since such devices are used in a large number of vehicles, it is necessary to make corresponding sensor devices available for a large number of vehicle types. The vehicle types may differ in particular with regard to the angle of attack of the windshield relative to the sensor device and with regard to the possible distances at which the sensor device can be arranged relative to the windshield. It is particularly important here to achieve a sufficient signal strength, i.e. a sufficient radiation intensity, for different angles of attack and distances. Summary of the invention

[0004] The object of the present invention is to provide a device for detecting deposits on windshields, which allows early detection of deposits on windshields, such as moisture deposits and / or ice deposits, and with which a sufficient signal strength can be achieved for various installation situations in a vehicle.

[0005] This object is achieved with a method having the features of patent claim 1 and with a vehicle having the features of patent claim 19 .

[0006] In the case of a sensor device for detecting deposits, in particular water deposits, such as moisture deposits and / or ice deposits, on the inner side of a glass pane, in particular a vehicle glass pane, a radiation transmitter for irradiating the glass pane and a radiation receiver for detecting the radiation intensity of radiation reflected by the glass pane, wherein at least one optical body having at least one radiation-conducting element is assigned to the radiation transmitter and / or the radiation receiver, it is provided according to the invention that the radiation-conducting element has at least two segments, each segment having at least one refractive surface, and the refractive surface is arranged facing the radiation transmitter and / or the radiation receiver.

[0007] The inner side of a glass sheet, in particular a vehicle glass sheet, such as a windshield of a vehicle, is irradiated with radiation by means of a radiation source. For example, a light-emitting diode can be used as a radiation source, with which radiation outside the range visible to the human eye is radiated. For example, the radiation can be emitted in a pulsed manner. The radiation is directed to the glass sheet at a fixed angle. At least one, in particular exactly one, radiation receiver is provided. For example, a photodiode can be used as a radiation receiver. Depending on the state of the glass sheet, i.e., depending on the deposition state, the radiation emitted by the radiation source is reflected, in particular scattered or reflected onto the radiation receiver. In the case of a glass sheet covered with moisture, frost, ice or other deposits, the radiation is not only reflected, but also scattered. Thus, less radiation is incident on the radiation receiver, which is indicated by a lower radiation intensity, because the radiation is reflected onto a larger area. By evaluating the detected radiation intensity values, the state of the deposits on the glass can be inferred. The separation accuracy between the state of the covered, in particular iced windshield and the state of the free windshield is very important for the quality of the detection. The evaluation can be performed, for example, with the aid of an evaluation device, such as a computing device. In order to achieve the highest possible radiation yield at different angles of attack and different distances relative to the windshield, the sensor device has an optical body, which has at least one radiation-conducting element, preferably two radiation-conducting elements. The optical body can be a type of lens body made of a radiation-permeable material, such as a transparent plastic. In this case, one radiation-conducting element can be assigned to the radiation transmitter and one radiation-conducting element can be assigned to the radiation receiver. The emitted radiation is guided to the area on the windshield by the radiation-conducting element assigned to the radiation transmitter, so that the best possible and large-area irradiation can be achieved here. The viewing cone of the sensor device is influenced by the radiation-conducting element. The highest possible radiation intensity should be achieved by the radiation-conducting element assigned to the radiation receiver, that is, the highest possible component of radiation reflected by the windshield, that is, reflected or scattered onto the radiation receiver. In order to achieve the greatest possible variability for the arrangement of the sensor device behind the windshield, in particular the distance and angle of attack of the sensor device relative to the windshield, the radiation-conducting element has segments, in particular stepped segments arranged from top to bottom. Different refractive surfaces are formed by step-shaped segmentation, which face the sensor elements, ie the radiation transmitter and the radiation receiver. The radiation-conducting elements, in particular the refractive surfaces, can each have a convex curvature, wherein the curvature is formed in the direction of the respectively assigned sensor element and descends toward the edge of the respective radiation-conducting element.Due to the convex arch structure and the stepped construction, at different spacings and different elevation angles, on the one hand, the widest possible cone of view of the sensor device can be achieved by the radiation transmitter, and on the other hand, the most comprehensive possible detection of the light reflected by the windshield can be achieved by the radiation receiver, and thus a high radiation yield and thus a signal yield can be achieved.

[0008] In one embodiment of the invention, a radiation-conducting element is assigned to each of the radiation transmitter and the radiation receiver. In order to achieve the best possible illumination and a large area, the radiation-conducting element is assigned to the radiation transmitter. The emitted radiation is guided by the radiation-conducting element to the area on the windshield. The reflected or scattered radiation is guided to the radiation receiver by the radiation-conducting element assigned to the radiation receiver.

[0009] In a further development of the invention, the radiation-conducting element is designed in a stepped manner, wherein the steps are formed from segments arranged from top to bottom. The segments of the radiation-conducting element can be arranged from top to bottom in such a way that a stepped structure of the radiation-conducting element results. The stepped structure makes it possible to achieve a high signal yield at different angles of attack of the sensor device relative to the windshield and at different distances.

[0010] In one embodiment of the invention, the optical body is designed in one piece and forms a radiation-conducting element assigned to the radiation transmitter and a radiation-conducting element assigned to the radiation receiver. By designing the optical body in one piece with two radiation-conducting elements, a space-saving design of the sensor device and a time-efficient assembly of the optical body can be achieved.

[0011] In a further development of the invention, the radiation-conducting element has a convex arched structure in the direction of the radiation transmitter and / or in the direction of the radiation receiver. In particular, each step can have a convex arched structure, wherein the arched structure extends substantially along the step edge. In particular, the arched structure can be designed so that the distance of the radiation-conducting element from the corresponding sensor element has a minimum value in the center of the step. As a result, the middle area of ​​the radiation-conducting element has a smaller distance to the corresponding sensor element than the edge area.

[0012] In an improved solution of the present invention, each refractive surface substantially forms a convex arched structure along the corresponding step. The step edge may substantially have the same arched structure as the corresponding refractive surface.

[0013] In a further development, the sensor device is designed for arrangement behind a windshield of a vehicle in an angle of attack range and in a distance range. The stepped arrangement of the segments ensures an optimized signal yield, ie an optimized conduction of the radiation reflected by the windshield to the radiation receiver.

[0014] In a further development of the invention, each radiation-conducting element has three steps, each of which is configured to conduct radiation primarily in a section of an angular range between the sensor device and the windshield and / or in a section of a distance range between the sensor device and the windshield. A sufficient radiation yield, i.e., a signal quality, can be achieved by means of the three steps for different distances of the sensor device relative to the windshield. Preferably, in the installed state of the sensor device, the steps are arranged one on top of the other, so that there is an upper step, an intermediate step, and a lower step. Depending on whether the sensor device is positioned closer or farther from the windshield, the radiation is refracted more by the upper step, the intermediate step, or the lower step. The three segments, i.e., the three steps, are arranged and configured so that, at a specific angle or a specific distance of the sensor device relative to the windshield of the vehicle, radiation conduction is primarily performed by one of the segments arranged from top to bottom. For example, the angular range may be a range of 10° to 40°, in particular 15° to 35°. For example, in the case of an intermediate angular range, radiation conduction may be primarily performed by the segment arranged in the center.

[0015] In a further development of the invention, the three-step refractive surface has different angles of attack relative to the radiation transmitter and / or the radiation receiver. The three-step refractive surface has different elevation angles relative to the radiation transmitter and the radiation receiver and thus also relative to the windshield. Due to the different angles of attack of the refractive surface, each refractive surface takes over the main conduction of the radiation in different angular ranges or distance ranges of the sensor device relative to the windshield. As a result, a high radiation intensity and thus a signal yield can be achieved in a wide angular range and distance range of the sensor device relative to the windshield.

[0016] In one development, the optical body has a planar region and the radiation-conducting element is arranged on a side facing away from the planar region. In particular, the optical body can have two radiation-conducting elements arranged on a side facing away from the planar region. The planar region can, for example, form an exit region or an entrance region for the radiation. In particular, the planar region can form an outer wall of a housing of the sensor device at least in sections in order to enable radiation exit or radiation entrance from the housing.

[0017] In a further development of the sensor device according to the invention, at least one refractive surface has two refractive regions, and the refractive regions are arranged laterally adjacent to each other. In this case, the step forms a refractive surface, wherein the refractive surface has two refractive regions arranged laterally adjacent to each other. In this case, the refractive regions merge into each other. By means of the adjacently arranged refractive regions of the refractive surface, a good radiation distribution is achieved at different angles.

[0018] In a further development of the present invention, the radiation conducting element has an upper boundary surface and a lower boundary surface, respectively, the upper edge of the upper boundary surface and the lower edge of the lower boundary surface are arranged substantially parallel to each other, and the projection of the step edge of the lower step onto the plane spanned by the planar region and the lower edge of the lower boundary surface are arranged substantially parallel to each other. The imaginary projection of the forwardly raised step edge of the lower step onto the plane spanned by the planar region is arranged substantially parallel to the lower edge of the radiation conducting element. Here, the lower step can be designed as a stronger step than the two steps arranged above it.

[0019] In one embodiment of the invention, the projection of the step edge of the upper step onto the plane spanned by the planar region has an arched structure relative to the upper edge in the direction of the lower edge. The imaginary projection of the forwardly raised step edge of the upper step onto the plane spanned by the planar region is raised in the middle region relative to the lower edge of the radiation-conducting element. Due to the curved course of the step edge between the upper step and the middle step, the upper step is designed to be more expanded. This results in radiation conduction in a wide angular range between the sensor device and the windshield.

[0020] In one embodiment of the invention, the edge of the upper boundary surface and the edge of the lower boundary surface have a curvature in the direction of the sensor element on their side facing away from the planar region. The curvature of the edge of the boundary surface substantially predetermines the convex curvature of the refractive surface.

[0021] In one embodiment of the invention, the optics body has no undercuts. Since there are no undercuts in the shape of the optics body, it is possible to produce the optics body simply and cost-effectively, for example by means of an injection molding method.

[0022] In a further development of the invention, the refractive areas merge into one another and have no additional refraction-generating edges. The refractive areas of the refractive surface merge into one another in such a way that no additional edges are formed that disrupt the beam path by scattering or refraction.

[0023] In one embodiment of the present invention, the lower step is more strongly expressed than the upper step. Due to the different intensities of the different steps, very good signal quality, ie, radiation intensity, can be achieved at different angles and at different distances.

[0024] In one embodiment of the invention, in cross section, the refractive surface of the upper step and the refractive surface of the middle step form an angle, wherein the transition region between the refractive surfaces of the upper step and the middle step is oriented toward the radiation transmitter and / or the radiation receiver and the lower step is arranged substantially parallel to the middle step. The imaginary cross section can extend, for example, between the corresponding adjacently arranged refractive areas of the refractive surface in the center through the upper boundary surface and the lower boundary surface. In this cross section, the outer edge of the refractive surface of the upper step and the outer edge of the middle step lead to each other, so that the outer edges are angled together in the cross section. In the cross section, the outer edges of the refractive surface of the lower step and the middle step are essentially parallel in the cross section.

[0025] The invention further relates to a vehicle having a windshield and having a sensor device according to the invention, wherein the sensor device is arranged in the interior of the vehicle behind the windshield and wherein the sensor device can be positioned at different distances relative to the windshield. By designing the radiation-conducting element in a stepped manner, different distances of the sensor device relative to the windshield can be achieved without loss of signal quality. The sensor device can thus be installed in different vehicle types without further adaptation.

[0026] In one embodiment of the invention, the sensor device can be positioned at different angles of attack relative to the windshield. The angle between the sensor device, in particular the housing of the flat region of the optical body, and the windshield can be selected within a range without causing a loss in signal quality. The sensor device can thus be used in different vehicle types without adaptation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further explained below based on the embodiments shown in the accompanying drawings. The same components are shown with the same reference numerals. In detail, the schematic diagram is in the following figure:

[0028] Figure 1 : A sensor device is shown in a cross-sectional view;

[0029] Figure 2 : An optical body is shown in a perspective view;

[0030] Figure 3 :Shown in front view according to Figure 2 The optical body;

[0031] Figure 4 :Shown in side view according to Figure 2 The optical body;

[0032] Figure 5 : Shows the front of the windshield Figure 2 The optical body;

[0033] Figure 6 : shows the sensor device in front of the windshield panel; and

[0034] Figure 7 : A sensor device in front of the windshield plate having an optical path. DETAILED DESCRIPTION

[0035] exist Figure 1 , a sensor device 1 with a radiation transmitter 2 and a radiation receiver 3 is shown in cross section. The sensor device 1 is arranged in the region of a black print 5 of a windshield 4. The sensor device 1 has a housing 6 with a radiation-permeable region 7. An optical body 8 is assigned to the radiation transmitter 2, which can be designed as an LED, for example. Through the optical body 8, the radiation emitted by the radiation transmitter 2 is guided at a fixed angle to the windshield 4, where, in the case of a free windshield, the radiation is reflected according to the law of reflection to the radiation receiver 3. The radiation transmitter 2 and the radiation receiver 4 are arranged on a circuit carrier 9. The housing 6 has an interface 10 for data transmission connection, for example with evaluation electronics or the like. In the case of deposits 11 on the windshield 4, for example in the form of frost, ice or water vapor, the radiation 12 emitted by the radiation transmitter 2 is reflected by the inner side of the windshield 4 not only in the form of reflected radiation, but also in the form of scattered radiation. Due to the scattering of the emitted radiation 12, the radiation is reflected over a wider area, so that the intensity of the radiation detected by means of the radiation receiver 3 is reduced. Due to the reduced radiation intensity, deposits 11 on the windshield 4 can be detected.

[0036] exist Figure 2, an optical body 8 with radiation-conducting elements 13, 14 is shown. The radiation-conducting elements 13, 14 are formed on the side of the optical body 8 facing the sensor elements 2, 3. The radiation-conducting element 13 is assigned to the radiation transmitter 2, and the radiation-conducting element is assigned to the radiation receiver 3. The radiation-conducting elements 13, 14 each have three stepped sections, namely three steps 15, 16, 17, and each have an upper boundary surface 30 and a lower boundary surface 31. The steps are arranged so that there is an upper step 15, an intermediate step 16 and a lower step 17. The steps form refractive surfaces 18, 19 and 20, respectively. Each refractive surface has two adjacently arranged refractive areas 21. On the side facing away from the radiation-conducting elements 13, 14, the optical body has a planarly formed area 22, which is the radiation-permeable area 7 of the housing 6. The steps 15-17 make it possible to adapt the distance between the sensor device 1 and the windshield 4 and the angle of attack without any loss of signal quality.

[0037] exist Figure 3 The top view shows the Figure 2 The imaginary projection of the forwardly raised step edge 25 of the lower step 17 onto the plane spanned by the planar region 22 is arranged substantially parallel to the lower edge 23 of the radiation conducting elements 13, 14. In this case, the lower step 17 can be designed as a stronger step than the two steps 15, 16 arranged above it.

[0038] The imaginary projection of the forwardly raised step edge of upper step 15 onto the plane spanned by flat region 22 is curved in the middle region relative to lower edge 23 of radiation conducting elements 13, 14. Due to the curved course of step edge 24 between upper step 15 and middle step 16, upper step 15 is designed to be more expanded.

[0039] exist Figure 4 The side view shows the Figure 2 and 3 The optical body 8 of FIG. The lower step 17 is more strongly expressed than the steps 15 and 16. The outer edge of the refractive surface 20 of the lower step 17 is arranged substantially parallel to the outer edge of the refractive surface 19 of the middle step 16 in the cross section. The outer edges of the refractive surfaces 18 and 19 of the upper step 15 and the middle step 16 form an angle in the cross section.

[0040] exist Figure 5 In, according to Figures 2 to 4 Optical body 8 is arranged in front of windshield 4. Radiation-conducting elements 13 and 14 form a viewing cone 26 of sensor device 1.

[0041] exist Figure 62 shows the orientation of sensor device 1 in front of windshield 4. Due to the stepped design of radiation-conducting elements 13 and 14, both distance 27 and angle 28 can be varied without radiation losses occurring.

[0042] exist Figure 7 , the sensor device 1 is arranged relative to the windshield 4. The beam path 26 of the radiation emitted by the radiation transmitter 2 and reflected by the windshield 4 to the radiation receiver is shown. By designing the optical body 8, an optimized radiation guidance can be achieved for different angles of attack and distances of the sensor device 1 relative to the windshield 4.

Claims

1. A sensor device (1) for detecting deposits, in particular water deposits, such as moisture deposits and / or ice deposits, on a glass pane (4), in particular on the inner side of a vehicle glass pane, comprising a radiation transmitter (2) for irradiating the glass pane (4) and a radiation receiver (3) for detecting the radiation intensity of radiation reflected by the glass pane (4), and wherein at least one optical body (8) having at least one radiation-conducting element (13, 14) is associated with the radiation transmitter (2) and / or the radiation receiver (3), characterized in that The radiation conducting element (13, 14) has at least two segments, each segment having at least one refractive surface (18, 19, 20), and The refractive surfaces (18, 19, 20) are arranged facing the radiation transmitter (2) and / or the radiation receiver (3).

2. The sensor device according to claim 1, characterized in that A radiation-conducting element (13, 14) is respectively assigned to the radiation transmitter (2) and the radiation receiver (3).

3. The sensor device according to any one of claims 1 or 2, characterized in that The radiation-conducting elements (13, 14) are designed in a stepped manner, wherein the steps (15, 16, 17) are formed from segments arranged from top to bottom.

4. The sensor device according to any one of claims 1 to 3, characterized in that The optical body (8) is designed in one piece and forms a radiation-conducting element (13) assigned to the radiation transmitter (2) and a radiation-conducting element (14) assigned to the radiation receiver (3).

5. The sensor device according to any one of claims 1 to 4, characterized in that At least one radiation-conducting element (13, 14) has a convexly curved structure in the direction of the radiation transmitter (2) and / or the radiation receiver (3).

6. The sensor device according to any one of claims 1 to 5, characterized in that Each refractive surface (18, 19, 20) substantially forms a convex arch structure along the corresponding step (15, 16, 17).

7. The sensor device according to any one of claims 1 to 6, characterized in that The sensor device is designed to be arranged behind a windshield of the vehicle in a range of attack angles and in a range of spacings.

8. The sensor device according to any one of claims 1 to 7, characterized in that The radiation-conducting elements (13, 14) each have three steps (15, 16, 17), each of which is designed to conduct radiation primarily in a section of an angular range between the sensor device (1) and the windshield (4) and / or in a section of a distance range between the sensor device (1) and the windshield (4).

9. The sensor device according to any one of claims 1 to 8, characterized in that The refractive surfaces (18, 19, 20) of the three steps (15, 16, 17) have different angles of attack relative to the radiation transmitter (2) and / or the radiation receiver (3).

10. The sensor device according to any one of claims 1 to 9, characterized in that The optics body (8) has a planar region (22), and the radiation-conducting elements (13, 14) are arranged on a side facing away from the planar region (22).

11. The sensor device according to any one of claims 1 to 7, characterized in that At least one refractive surface (18, 19, 20) has two refractive regions (21), and the refractive regions (21) are arranged laterally adjacent to each other.

12. The sensor device according to any one of claims 1 to 11, characterized in that The radiation-conducting elements (13, 14) each have an upper boundary surface (30) and a lower boundary surface (31), wherein an upper edge (29) of the upper boundary surface (30) and a lower edge (23) of the lower boundary surface (31) are arranged substantially parallel to each other, and a projection of a step edge (25) of the lower step (17) onto a plane spanned by the planar region (22) and a lower edge (23) of the lower boundary surface (31) are arranged substantially parallel to each other.

13. The sensor device according to any one of claims 10 to 13, characterized in that A projection of a step edge (24) of the upper step (15) onto a plane spanned by the planar region (8) has a curved structure relative to the upper edge (29) in the direction of the lower edge (23).

14. The sensor device according to any one of claims 1 to 13, characterized in that The edge of the upper boundary surface (30) and the edge of the lower boundary surface (31) have a curvature in the direction of the sensor element (2, 3) on their side facing away from the region (8) designed in a planar manner.

15. The method according to any one of claims 1 to 14, characterized in that: The optical body (8) has no undercut.

16. The sensor device according to any one of claims 1 to 15, characterized in that The refractive regions (21) merge into one another and have no additional refraction-generating edges.

17. The sensor device according to any one of claims 1 to 16, characterized in that The lower step (17) is more pronounced than the upper step (15).

18. The sensor device according to any one of claims 1 to 17, characterized in that In cross section, the refractive surface (18) of the upper step (15) and the refractive surface (19) of the intermediate step (16) form an angle, wherein a transition region between the refractive surfaces (18) of the first step (15) and the intermediate step (16) is oriented toward the radiation transmitter (2) and / or the radiation receiver (3), and the refractive surface (20) of the lower step (17) is arranged substantially parallel to the refractive surface (19) of the intermediate step (16).

19. A vehicle having a windshield (4) and a sensor device (1) according to the invention as claimed in any one of the preceding claims, wherein the sensor device (1) is arranged behind the windshield (4) in the interior space of the vehicle and wherein the sensor device (1) can be positioned at different distances (27) relative to the windshield (4).

20. The vehicle according to claim 19, characterized in that The sensor device (1) can be positioned at different angles of attack (28) relative to the windshield (4).

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