Sensor device for detecting deposits on a disc

Abstract

In a sensor device for detecting deposits, in particular water deposits such as moisture deposits and / or ice deposits on a pane, especially on the inside of a vehicle window, comprising a radiation transmitter for irradiating the pane and a radiation receiver for detecting the radiation intensity of the radiation reflected from the pane, and wherein at least one optical body with at least one radiation guiding element is associated with the radiation transmitter and / or the radiation receiver, it is essential to the invention that the radiation guiding element has at least two segments, that each segment has at least one refractive surface, and that the refractive surface is arranged facing the radiation transmitter and / or the radiation receiver.

Description

[0001] The invention relates to a sensor device for detecting deposits, in particular water deposits such as moisture deposits and / or ice deposits on a window, in particular on the inside of a vehicle window, with a radiation transmitter for irradiating the window and with a radiation receiver for detecting the radiation intensity of the radiation reflected by the window, wherein the radiation receiver is designed to detect the scattered radiation intensity of the radiation scattered by the window, and wherein at least one optical body with at least one radiation guiding element is assigned to the radiation transmitter and / or the radiation receiver.

[0002] The detection of deposits such as dirt or water deposits, such as fogging, ice deposits, or even frost, can be of great importance for the safe driving of a vehicle. The formation of deposits can, on the one hand, impair the driver's visibility and, on the other hand, can disrupt the function of a display projected onto the inside of the windshield, i.e. the function of a so-called head-up display. This means that the driver cannot properly visually see relevant information, such as the fuel gauge, battery charge level, sign recognition, current speed, and the like. A windshield that is icy, covered in frost, fogged up, or dirty leads to a distortion of the projected information.This can lead to the driver being unable to obtain the information necessary for safe participation in road traffic, or to misinterpret it. If frost, ice, or fogging forms on the inside of the windshield, the driver must be informed accordingly, or the control of the head-up display must be adjusted. This requires early detection of these deposits. Sensor devices for detecting fogging are known, for example, from DE 10 2006 039 034 A1.

[0003] Since such devices are used in a wide variety of vehicles, it is necessary to design a corresponding sensor device that can be used for a wide variety of vehicle types. Vehicle types can differ, in particular, in the angle of the windshield relative to the sensor device and in the possible distance at which the sensor device can be positioned from the windshield. It is particularly crucial here to achieve sufficient signal strength, i.e., sufficient radiation intensity, for different angles and distances.

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

[0005] This problem is solved by a method having the features of patent claim 1 and by a vehicle having the features of patent claim 19.

[0006] In a sensor device for detecting deposits, in particular water deposits such as moisture deposits and / or ice deposits on a window, in particular on the inside of a vehicle window, with a radiation transmitter for irradiating the window and with a radiation receiver for detecting the radiation intensity of the radiation reflected by the window, and wherein at least one optical body with at least one radiation guiding element is assigned to the radiation transmitter and / or the radiation receiver, it is provided as an essential part of the invention that the radiation guiding element has at least two segments, that each segment has at least one refractive surface and that the refractive surfaces are arranged facing the radiation transmitter and / or the radiation receiver.

[0007] The window, in particular the inside of the vehicle window, for example the windshield of a vehicle, is irradiated with radiation from a radiation source. The radiation source can be a light-emitting diode, for example, which emits radiation outside the range visible to the human eye. The radiation can be emitted in pulses, for example. The radiation is directed onto the window at a fixed angle. At least one, in particular exactly one, radiation receiver is provided. A photodiode, for example, can serve as the radiation receiver. Depending on the condition of the window, i.e. depending on the state of deposits, the radiation emitted by the radiation source is thrown back onto the radiation receiver, in particular scattered or reflected. If the window is covered with moisture, frost, ice or other deposits, the radiation is not only reflected but also scattered.This means that less radiation hits the radiation receiver, which is indicated by lower radiation intensity because the radiation is reflected over a larger area. By evaluating the recorded radiation intensity values, conclusions can be drawn about the condition of the deposits on the windshield. The discriminatory power between the conditions of a covered, particularly icy, windshield and a clear windshield is crucial for the quality of the detection. The evaluation can be carried out, for example, using an evaluation device such as a computing device. In order to achieve the highest possible radiation yield at different angles of incidence and different distances from the windshield, the sensor device has an optical body with at least one, preferably two, radiation-guiding elements.The optical body can be a type of lens body made of a radiation-permeable material, such as a transparent plastic. A radiation guide element can be assigned to the radiation transmitter and a radiation guide element can be assigned to the radiation receiver. The radiation guide element assigned to the radiation transmitter directs the emitted radiation onto an area on the windshield so that the best possible and largest-area irradiation can be achieved. The radiation guide element influences the field of view of the sensor device. The radiation guide element assigned to the radiation receiver is intended to achieve the highest possible radiation intensity, i.e. the highest possible proportion of the radiation thrown back by the windshield, i.e. reflected or scattered, onto the radiation receiver.To achieve the greatest possible variability for the arrangement of the sensor device behind the windshield, in particular the distances and the angle of incidence of the sensor device relative to the windshield, the radiation-guiding elements have segments, in particular step-like segments arranged one below the other. The step-like segments form various refractive surfaces facing the sensor elements, i.e., the radiation transmitter and the radiation receiver. The radiation-guiding 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 elements and slopes downwards toward the edges of the respective radiation-guiding element.The convex curvature and the step-like design enable the sensor device to have the widest possible field of view through the radiation transmitter and the most comprehensive possible detection of the light reflected by the windshield by the radiation receiver at different distances and different angles of attack, thus achieving a high radiation yield and thus signal yield.

[0008] In one embodiment of the invention, a radiation guide element is each assigned to the radiation transmitter and the radiation receiver. To achieve the best possible and wide-area irradiation, a radiation guide element is assigned to the radiation transmitter. This element directs the emitted radiation onto an area on the windshield. The radiation guide element, which is assigned to the radiation receiver, directs the reflected or scattered radiation to the radiation receiver.

[0009] In a further development of the invention, the radiation-guiding elements are designed in a stepped manner, with the steps being formed by the segments arranged one below the other. The segments of the radiation-guiding elements can be arranged one below the other in such a way that a stepped structure of the radiation-guiding elements results. This stepped design allows for a high signal yield at different angles of incidence and at different distances between the sensor device and the windshield.

[0010] In one embodiment of the invention, the optical body is formed as a single piece, and the optical body forms the radiation guiding element assigned to the radiation transmitter and the radiation guiding element assigned to the radiation receiver. The single-piece design of the optical body with the two radiation guiding elements enables a space-saving design of the sensor device and time-efficient assembly of the optical body. In a further development of the invention, the radiation guiding elements each have a convex curvature in the direction of the radiation transmitter and / or in the direction of the radiation receiver. In particular, each step can have a convex curvature, wherein the curvature runs essentially along the step edges. In particular, the curvature can be formed such that the distance between the radiation guiding element and the respective sensor element is minimum in the middle of the step.The central area of ​​a radiation guiding element is therefore at a smaller distance from the respective sensor element than the edge areas.

[0011] In a further development of the invention, each refractive surface forms a convex curvature substantially along the respective step. The step edges can have substantially the same curvature as the respective refractive surfaces.

[0012] In a further development, the sensor device is designed for placement in a range of angles of incidence and at a distance behind the windshield of a vehicle. The stepped arrangement of the segments ensures optimized signal yield, i.e., optimized transmission of the radiation reflected by the windshield to the radiation receiver.

[0013] In a further development of the invention, each radiation guiding element has three stages, each of which is designed to primarily guide the radiation in a section of the angular range between the sensor device and the windshield and / or in a section of the distance range between the sensor device and the windshield. The three stages enable sufficient radiation yield, i.e. signal quality, for different distances between the sensor device and the windshield. Preferably, the stages are arranged one above the other when the sensor device is installed, so that there is an upper, a middle, and a lower stage. Depending on whether the sensor device is positioned closer or further away from the windshield, the radiation is refracted more by the upper, middle, or lower stage.The three segments, i.e., the three stages, are arranged and configured such that, at a specific angle or a specific distance of the sensor device from the windshield of a vehicle, radiation conduction occurs primarily through one of the segments arranged one below the other. For example, the angular range can be from 10° to 40°, in particular from 15° to 35°. For example, in a medium angular range, radiation conduction can occur primarily through the centrally arranged segment.

[0014] In a further development of the invention, the refractive surfaces of the three stages have different angles of incidence relative to the radiation transmitter and / or the radiation receiver. The refractive surfaces of the three stages have different angles of incidence relative to the radiation transmitter and the radiation receiver, and thus also relative to the windshield. Due to the different angles of incidence of the refractive surfaces, each refractive surface primarily guides the radiation in a different angular range or distance range of the sensor device from the windshield. This allows for high radiation intensity and thus signal yield to be achieved across a wide angular range and distance range of the sensor device from the windshield.

[0015] In a further development, the optical body has a planar region, and the radiation-guiding elements are arranged on the side facing away from the planar region. In particular, an optical body can have two radiation-guiding elements arranged on the side facing away from the planar region. The planar region can, for example, form the exit region or the entry region of the radiation. In particular, the planar region can form the outer wall of a housing of the sensor device, at least in sections, in order to enable the radiation to exit or enter the housing.

[0016] 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 one another. A step forms a refractive surface, with one refractive surface having two refractive regions arranged laterally adjacent to one another. The refractive regions merge into one another.

[0017] By arranging the refraction areas of a refraction surface next to each other, a good radiation distribution is achieved at different angles.

[0018] In a further development of the invention, the radiation guiding elements each have an upper boundary surface and a lower boundary surface, an upper edge of the upper boundary surface and a lower edge of the lower boundary surface are arranged substantially parallel to one another, and a projection of the step edge of the lower step onto the plane spanned by the flat region and the lower edge of the lower boundary surface are arranged substantially parallel to one another. An imaginary projection of the forward-curved step edge of the lower step onto a plane spanned by the flat region is arranged substantially parallel to the lower edge of the radiation guiding element. The lower step can be designed as a stronger step than the two steps arranged above it.

[0019] In one embodiment of the invention, a projection of the step edge of the upper step onto the plane spanned by the flat region has a curvature in the direction of the lower edge relative to the upper edge. An imaginary projection of the forward-curved step edge of the upper step onto a plane spanned by the flat region is curved in the central region toward the lower edge of the radiation-guiding element. Due to the curved shape of the step edge between the upper and middle steps, the upper step has a more bulbous design. This results in radiation guidance over 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 elements on their side facing away from the flat region. The curvatures of the edges of the boundary surfaces essentially determine the convex curvature of the refractive surfaces.

[0021] In one embodiment of the invention, the optical body has no undercuts. The absence of undercuts in the shape of the optical body allows for simple and cost-effective production of the optical body, for example, by an injection molding process.

[0022] In a further development of the invention, the refraction regions merge into one another and do not have any additional refraction-generating edges. The refraction regions of a refraction surface merge into one another in such a way that no edges are formed that could further disrupt the beam path through scattering or refraction.

[0023] In one embodiment of the invention, the lower step is more pronounced than the upper steps. Due to the varying intensity of the different steps, very good signal quality, i.e., radiation intensity, can be achieved at different angles and distances.

[0024] In one embodiment of the invention, the refractive surfaces of the upper stage and the refractive surfaces of the middle stage form an angle in a cross-section, wherein the transition region between the refractive surfaces of the upper stage and the middle stage is oriented towards the radiation transmitter and / or the radiation receiver and the lower stage is arranged substantially parallel to the middle stage. The imaginary cross-section through a flow guiding element can, for example, run centrally through the upper and lower boundary surfaces, between the respective refractive regions of a refractive surface arranged next to one another. In this cross-section, the outer edges of the refractive surfaces of the upper stage and the outer edge of the middle stage converge towards one another, so that together they form an angle in the cross-section.In cross-section, the outer edges of the refractive surfaces of the lower and middle stages run essentially parallel in a cross-section.

[0025] The invention further relates to a vehicle with a windshield and with 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 various distances from the windshield. The stepped design of the radiation guide elements allows for different distances between the sensor device and the windshield without any loss of signal quality. The sensor device can thus be installed in various vehicle types without further adaptation.

[0026] In one embodiment of the invention, the sensor device can be positioned at various angles relative to the windshield. The angle between the housing of the sensor device, in particular the flat area of ​​the optical body, and the windshield can be selected within a range without causing any loss of signal quality. Thus, the sensor device can be used in various vehicle types without adjustment.

[0027] The invention is further explained below using an exemplary embodiment illustrated in the drawing. Identical components are denoted by the same reference numerals. The schematic representations show in detail: Fig. 1: a sensor device in a sectional view; Fig. 2: an optical body in a perspective view; Fig. 3: an optical body according to Fig. 2 in a front view; Fig. 4: an optical body according to Fig. 2 in a side view; Fig. 5: an optical body according to Fig. 2 in front of a windshield; Fig. 6: a sensor device in front of a windshield; and Fig. 7: a sensor device in front of a windshield with beam path.

[0028] In Fig. 1 shows a cross-section of a sensor device 1 with a radiation transmitter 2 and a radiation receiver 3. The sensor device 1 is arranged in the area of ​​a black print 5 of a windshield 4. The sensor device 1 has a housing 6 with a radiation-permeable region 7. The radiation transmitter 2, which can be designed as an LED, for example, is assigned an optical body 8. The radiation emitted by the radiation transmitter 2 is guided by the optical body 8 at a fixed angle onto the windshield 4, where, in the case of a clear windshield, the radiation is reflected onto the radiation receiver 3 according to the law of reflection. 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-conducting connection, for example to evaluation electronics or the like.In the case of a deposit 11, for example in the form of frost, ice, or fogging, on the windshield 4, the radiation 12 emitted by the radiation transmitter 2 is reflected from the inside 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 radiation intensity detected by the radiation receiver 3 is reduced. Due to the reduced radiation intensity, the detection of a deposit 11 on the windshield 4 is possible.

[0029] In the Fig. 2 shows an optical body 8 with radiation-guiding elements 13, 14. The radiation-guiding elements 13, 14 are formed on the side of the optical body 8 facing the sensor elements 2, 3. The radiation-guiding element 13 is assigned to the radiation transmitter 2, and the radiation-guiding element is assigned to the radiation receiver 3. The radiation-guiding elements 13, 14 each have three step-like segments, i.e., three steps 15, 16, 17, and each have an upper boundary surface 30 and a lower boundary surface 31. The steps are arranged such that there is an upper step 15, a middle step 16, and a lower step 17. The steps each form refractive surfaces 18, 19, and 20. Each refractive surface has two refractive regions 21 arranged next to one another. On the side facing away from the radiation guiding elements 13, 14, the optical body has a flat region 22 which represents the radiation-permeable region 7 of the housing 6.Stages 15 - 17 allow adjustment of the distance between the sensor device 1 and the windshield 4 as well as adjustment of the angle of attack without any loss of signal quality.

[0030] In Fig. 3, the optical body 8 is according to Fig. 2 in a plan view. An imaginary projection of the forwardly curved step edge 25 of the lower step 17 onto a plane spanned by the flat region 22 is arranged essentially parallel to the lower edge 23 of the radiation-guiding element 13, 14. The lower step 17 can be designed as a stronger step than the two steps 15, 16 arranged above it.

[0031] An imaginary projection of the forward-curved step edge of the upper step 15 onto a plane spanned by the flat region 22 is curved in the central region toward the lower edge 23 of the radiation-guiding element 13, 14. Due to the curved shape of the step edge 24 between the upper step 15 and the middle step 16, the upper step 15 is more bulbous.

[0032] In Fig. 4 is an optical body 8 according to the Fig. 2 and Fig. 3 in a side view. The lower step 17 is more pronounced than steps 15 and 16. The outer edge of the refractive surface 20 of the lower step 17 is arranged in cross-section substantially parallel to the outer edge of the refractive surface 19 of the middle step 16. The outer edges of the refractive surfaces 18 and 19 of the upper step 15 and the middle step 16 form an angle in cross-section.

[0033] In Fig. 5, the optical body 8 is according to the Fig. 2 to 4 are arranged in front of a windshield 4. The radiation guiding elements 13 and 14 form the viewing cone 26 of the sensor device 1.

[0034] In Fig. Figure 6 shows the orientation of a sensor device 1 in front of a windshield 4. Both the distance 27 and the angle 28 can be changed by the stepped design of the radiation guide elements 13 and 14 without causing radiation losses.

[0035] In Fig. 7, a sensor device 1 is arranged relative to a windshield 4. The beam path 26 of the radiation emitted by the radiation transmitter 2 and reflected by the windshield 4 onto the radiation receiver is shown. The design of the optical body 8 enables optimized radiation guidance for different angles of incidence and distances of the sensor device 1 from the windshield 4. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This 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

[0000] DE 10 2006 039 034 A1

[0002]

Claims

[1] Sensor device (1) for detecting deposits, in particular water deposits such as moisture deposits and / or ice deposits on a pane (4), in particular on the inside of a vehicle pane, with a radiation transmitter (2) for irradiating the pane (4) and with a radiation receiver (3) for detecting the radiation intensity of the radiation reflected by the pane (4), and wherein at least one optical body (8) with at least one radiation guide element (13, 14) is assigned to the radiation transmitter (2) and / or the radiation receiver (3), characterized by that the radiation guiding element (13, 14) has at least two segments, that each segment has at least one refractive surface (18, 19, 20), and that the refractive surface (18, 19, 20) is arranged facing the radiation transmitter (2) and / or the radiation receiver (3). [2] Sensor device according to claim 1, characterized bythat a radiation guiding element (13, 14) is each assigned to the radiation transmitter (2) and the radiation receiver (3). [3] Sensor device according to one of claims 1 or 2, characterized by that the radiation guiding elements (13, 14) are designed in steps, wherein the steps (15, 16, 17) are formed by the segments arranged one below the other. [4] Sensor device according to one of claims 1 to 3, characterized by that the optical body (8) is formed in one piece and that the optical body (8) forms the radiation guiding element (13) assigned to the radiation transmitter (2) and the radiation guiding element (14) assigned to the radiation receiver (3). [5] Sensor device according to one of claims 1 to 4, characterized by that at least one radiation guiding element (13, 14) has a convex curvature in the direction of the radiation transmitter (2) and / or the radiation receiver (3). [6] Sensor device according to one of claims 1 to 5, characterized by that each refractive surface (18, 19, 20) forms a convex curvature substantially along the respective step (15, 16, 17). [7] Sensor device according to one of claims 1 to 6, characterized by that the sensor device is designed to be arranged in an angle of attack range and in a distance range behind the windshield of a vehicle. [8] Sensor device according to one of claims 1 to 7, characterized by that the radiation guiding elements (13, 14) each have three stages (15, 16, 17), that the three stages (15, 16, 17) are each designed to mainly guide the radiation in a section of the angular range between the sensor device (1) and the windscreen (4) and / or in a section of the distance range between the sensor device (1) and the windscreen (4). [9] Sensor device according to one of claims 1 to 8, characterized by that the refractive surfaces (18, 19, 20) of the three stages (15, 16, 17) have different angles of incidence to the radiation transmitter (2) and / or the radiation receiver (3). [10] Sensor device according to one of claims 1 to 9, characterized by that the optical body (8) has a flat region (22) and that the radiation guiding elements (13, 14) are arranged on the side facing away from the flat region (22). [11] Sensor device according to one of claims 1 to 7, characterized by that at least one refractive surface (18, 19, 20) has two refractive regions (21) and that the refractive regions (21) are arranged laterally next to one another. [12] Sensor device according to one of claims 1 to 11, characterized bythat the radiation guiding elements (13, 14) each have an upper boundary surface (30) and a lower boundary surface (31), that 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 one another and that a projection of the step edge (25) of the lower step (17) onto the plane spanned by the flat region (22) and the lower edge (23) of the lower boundary surface (31) are arranged substantially parallel to one another. [13] Sensor device according to one of claims 10 to 13, characterized by that a projection of the step edge (24) of the upper step (15) onto the plane spanned by the flat region (8) has a curvature in the direction of the lower edge (23) in relation to the upper edge (29). [14] Sensor device according to one of claims 1 to 13, characterized bythat 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 elements (2, 3) on their side facing away from the flat region (8). [15] Sensor device according to one of claims 1 to 14 characterized by that the optical body (8) has no undercuts. [16] Sensor device according to one of claims 1 to 15, characterized by that the refraction areas (21) merge into one another and have no additional refraction-generating edges. [17] Sensor device according to one of claims 1 to 16, characterized by that the lower level (17) is more pronounced than the upper level (15). [18] Sensor device according to one of claims 1 to 17, characterized byin that, in a cross-section, the refractive surface (18) of the upper stage (15) and the refractive surface (19) of the middle stage (16) span an angle, wherein the transition region between the refractive surfaces (18) of the first stage (15) and the middle stage (16) is oriented facing the radiation transmitter (2) and / or the radiation receiver (3) and the refractive surface (20) of the lower stage (17) is arranged substantially parallel to the refractive surface (19) of the middle stage (16). [19] Vehicle with a windshield (4) and with a sensor device (1) according to the invention according to one of the preceding claims, wherein the sensor device (1) is arranged in the interior of the vehicle behind the windshield (4) and wherein the sensor device (1) can be positioned at different distances (27) from the windshield (4). [20] Vehicle according to claim 19, characterized bythat the sensor device (1) can be positioned at different angles of attack (28) to the windshield (4).

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