Measurement setup with an optical transmitter and an optical receiver

Abstract

Measuring arrangement (4) with an optical transmitter (1) and an optical receiver (2), wherein the transmitter (1) is configured to emit electromagnetic measuring radiation (14) into a transmission chamber (16), wherein the receiver (2) is configured to receive measuring radiation (15) reflected from an object (10) in a receiving chamber (17), wherein means are provided to reduce the reception of interference radiation (37) by the receiver (2), which is not measurement radiation (15) reflected from the object (10), wherein the transmitter (1) is arranged in the receiving chamber (17), wherein the receiving chamber (17) adjoins the receiver (2) in a receiving area (3), wherein the transmitter (1) covers a partial area of ​​the receiving area (3) against reception of reflected measuring radiation (15), wherein an inactive area (34) is provided in the receiving area (3), wherein the inactive area (34) has at least a ring shape around the shaded partial area includes,wherein the receiver does not evaluate measurement radiation incident in the inactive area (34).

Description

[0001] The invention relates to a measuring arrangement with an optical transmitter and an optical receiver.

[0002] It is known in the prior art to mount an optical transmitter and an optical receiver side by side on a single carrier. To reduce interference radiation, which is measurement radiation not reflected by the object, a housing cover with two openings is provided between the object and the transmitter and receiver assembly. One opening is located above the transmitter and a second opening above the receiver. The opening above the receiver, in particular, reduces the reception of interference radiation.

[0003] US 2016 / 0 327 639 A1 describes a light grid.

[0004] US 2010 / 0 219 326 A1 describes an optoelectronic sensor that can be precisely aligned.

[0005] US 2015 / 0219763A1 describes an optoelectronic sensor for detecting objects in a surveillance area.

[0006] DE 10 2013 104 547 A1 describes a self-propelled soil cultivation machine.

[0007] EP 2 708 914 A1 describes an optoelectronic sensor for recording a depth map of a three-dimensional scene.

[0008] EP 2 998 700 A1 describes an electro-optical distance meter.

[0009] DE 10 2007 050 096 A1 describes an optical sensor.

[0010] The object of the invention is to provide an improved measuring arrangement with an optical transmitter and an optical receiver.

[0011] The object of the invention is achieved by the independent claim. Further embodiments of the invention are specified in the dependent claims.

[0012] One advantage of the proposed measurement setup is that it achieves a further reduction in interference radiation. This is accomplished by means of reducing the reception of interference radiation that is not reflected by the object.

[0013] The transmitter is located in the receiving space, and the transmitter partially blocks the reception of reflected measurement radiation. To reduce interference, the receiver's receiving surface has an inactive area. Within this inactive area, the received reflected measurement radiation is not evaluated. The inactive area has at least one ring shape surrounding the portion of the receiving surface that is shaded by the transmitter. The ring shape can also be a continuous surface that forms a ring around its outer edge. This surface can encompass the receiving surface shaded by the transmitter.

[0014] Positioning the transmitter above the receiver in the receiving area saves space. This allows the setup to be provided with a smaller footprint. Furthermore, the increased interference caused by placing the transmitter in the receiving area is compensated for or at least reduced by the inclusion of an inactive area. This inactive area is designed such that at least a portion of the interference caused by the transmitter's position in the receiving area is not detected and processed by the receiver. The inactive area can be achieved by either omitting a receiving surface within it or by covering the intended receiving surface and protecting it against the reception of reflected measurement radiation.Furthermore, the inactive area can be realized by ensuring that a designated receiving area is not active and is not used for receiving reflected measurement radiation.

[0015] In another embodiment, no receiving area is provided in the inactive region of the receiving surface. This limits the actual receiving area to the region actually intended for receiving measurement radiation.

[0016] In another embodiment, the receiving area is provided within the inactive surface area, but covered and protected against radiation reception. Thus, the inactive area of ​​the receiving surface is protected against both interference and measurement radiation. The covered area of ​​the receiving surface is specifically large enough or designed in such a way that little or no interference radiation is received.

[0017] In another embodiment, the receiving area is present in the inactive region, but deactivated. This can be achieved, for example, by a segmented receiving area, where one segment of the receiving area forms the inactive region and this segment is deactivated and not used for receiving measurement radiation.

[0018] In another version, a lens is provided in the transmitter's transmission chamber to focus the radiation onto a desired target area. This results in improved measurement evaluation.

[0019] In another embodiment, the lens is formed from a molding material, with the lens covering the transmitter and at least the receiver. In this embodiment, the receiver can also be provided with a lens. Forming the lens from a molding material is simple and inexpensive. Furthermore, in this way, both the lens for the transmitter and the lens for the receiver can be easily produced in a single step.

[0020] In another embodiment, the lens for the transmitter is mounted in a holder. The holder is attached to the transmitter and / or the receiver and positions the lens at a predetermined distance from the transmitter. The holder surrounds and covers the transmitter. Furthermore, the holder laterally encloses the lens, thus blocking any interference generated by the lens from reaching the receiver's receiving area. This reduces interference for the receiver.

[0021] In another embodiment, the transmitter is positioned on the receiver or on the receiver's receiving surface. This results in a simple design with a low-profile form factor.

[0022] In another embodiment, the receiver has a receiving area arranged on an evaluation chip. The receiving area is smaller than the evaluation chip, resulting in a simpler and more compact receiver design.

[0023] In another embodiment, a cover with a pass-through area is provided. The pass-through area is transparent to both the measurement radiation and the reflected measurement radiation. The pass-through area encompasses and defines the transmitting and receiving areas. The pass-through area is formed as a continuous surface. This cover allows for a further reduction of interference radiation while maintaining a compact design for the entire assembly.

[0024] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more readily understandable in connection with the following description of the exemplary embodiments, which are explained in more detail in conjunction with the drawings. These show Fig. 1 a schematic top view of a first embodiment of a measuring arrangement not according to the invention, comprising a transmitter and a receiver, Fig. 2 a schematic cross-section through the first embodiment, Fig. 3 a schematic representation of a receiver with a semicircular side contour of the receiving surface, Fig. 4 a schematic representation of a receiver with a U-shaped receiving area, Fig. 5 another embodiment of a receiver with several receiving surfaces arranged in a U-shape, Fig. 6 a schematic representation of a cross-section through a second embodiment of a measuring arrangement according to the invention, comprising a transmitter and a receiver, wherein the transmitter is arranged in the receiving space of the receiver, Fig. 7 a top view of the second measuring arrangement, Fig. 8 a cross-section through another embodiment of the second measuring arrangement, Fig. 9 a cross-section through another embodiment of the second measuring arrangement, Fig. 10 a schematic representation of a third measuring arrangement not according to the invention, Fig. 11 a schematic top view of a first embodiment of the receiver with segmented receiving surfaces, Fig. 12 a schematic top view of another embodiment of the receiver with strip-shaped circumferential receiving surfaces, and Fig. 13 a schematic top view of another embodiment of the receiver with annular receiving surfaces.

[0025] Fig. Figure 1 shows a schematic top view of a first embodiment of a measuring arrangement 4 with a transmitter 1 and a receiver 2. Part of the upper surface of the receiver 2 is designed as a receiving surface 3. A cover 5 is arranged over the measuring arrangement 4, the cover 5 being shown as transparent. The cover 5 has a transparent transmission area 6. The transmission area 6 is transparent to measurement radiation from the transmitter and to measurement radiation reflected from an object, which is received by the receiving surface 3. For example, the cover 5 can be made of an opaque material and the transmission area 6 can be in the form of an opening. Alternatively, the cover 5 can be made entirely of a transparent material and the area of ​​the cover 5 outside the transmission area 6 can be covered with an opaque layer.For example, the cover 5 can be made of sapphire or glass. The cover 5 can be in the form of a plate. The cover 5 is positioned over the measuring arrangement 4 such that electromagnetic radiation from the transmitter 1 can be transmitted through the pass-through area 6 to the object being measured. The pass-through area 6 is positioned relative to the receiving surface 3 such that measurement radiation reflected from the object being measured can be transmitted back through the pass-through area 6 to the receiving surface 3. One function of the cover 5 with the pass-through area 6 is to block interference radiation that is not measurement radiation reflected from the object. The cover 5 thus ensures that as much reflected measurement radiation as possible reaches the receiving surface 3 and as little interference radiation as possible reaches the receiving surface 3.

[0026] Transmitter 1 is configured to emit electromagnetic radiation, in particular infrared radiation, visible light, or ultraviolet radiation. Transmitter 1 can be configured, for example, as a light-emitting diode or a laser diode in the form of a semiconductor chip. Receiver 2 has an evaluation chip 7, wherein the evaluation chip 7 comprises electrical and / or electronic circuits for evaluating the reflected measurement radiation received by the receiving surface 3. The receiving surface 3 can, for example, be configured as a photodiode. Transmitter 1 and receiver 2 with the receiving surface 3 are arranged close to one another. The receiving surface 3, the passband 6, and transmitter 1 are configured such that the passband 6 is optimally utilized.

[0027] Fig. Figure 2 shows a schematic side view of the arrangement of Fig. 1. The transmitter 1 and the receiver 2 are arranged on a carrier 8. The cover 5 is designed as a transparent plate with an opaque layer 9 on its underside. The layer 9 has an opening in the form of the transmission area 6. A measurement object 10 is shown schematically above the cover 5. In the illustrated embodiment, the measuring arrangement 4 has a housing cover 11 that is opaque to electromagnetic radiation, in particular to the measurement radiation. The housing cover 11 is connected to the carrier 8 and protects the transmitter 1 and the receiver 2 from environmental influences. The housing cover 11 has a recess 12 formed above the transmitter 1 and above the receiving area 3. The recess 12 can be closed with a transparent material. In addition, a housing wall 13 is formed between the transmitter 1 and the receiver 2.The housing wall 13 extends from a top surface of the support 8 to a height above the transmitter 1 and the receiver 2. Furthermore, the housing wall 13 extends at least over one longitudinal side of the transmitter 1. In this way, direct radiation of measurement radiation onto the receiving surface 3 without reflection from the object 10 is avoided.

[0028] The transmitter 1 is configured to send measuring radiation 14 towards the object 10 to be measured through the recess 12 and through the passband 6. The object 10 reflects at least a portion of the measuring radiation 14 as reflected measuring radiation 15 back through the passband 6 and the recess 12 onto the receiving surface 3 of the receiver 2. The evaluation chip 7 is configured to detect and evaluate the reception of the reflected measuring radiation 15 in the receiving surface 3.

[0029] Depending on the chosen embodiment, the housing cover 11 can be made of a transparent material and be completely closed above the measuring arrangement 4 with the transmitter 1 and the receiver 2. In this embodiment, the transparent area of ​​the recess 12 is achieved by the housing cover 11 having an opaque layer. The opaque layer has a recess that corresponds to the shape of the recess 12.

[0030] Transmitter 1 emits the measurement radiation 14 into a transmission chamber 16. In the illustrated embodiment, the transmission chamber 16 is defined by the housing wall 13 and the recess 12. Simultaneously, a receiving chamber 17 is formed, through which measurement radiation 15 reflected from the object 10 is emitted back onto the receiving surface 3. The receiving chamber 17 is defined by the housing wall 13 and the recess 12. Both the transmission chamber 16 and the receiving chamber 17 are configured such that the object 10 is located in the transmission chamber 16 and the receiving chamber 17, respectively.

[0031] Depending on the chosen embodiment, a first optic 18 and / or a second optic 19 can be arranged above the transmitter 1 and / or above the receiver 2 for improved beam shaping. The first and second optics 18, 19 can, for example, be designed as individual lenses and arranged in or above the recess 12. Depending on the chosen embodiment, the first and second optics 18, 19 can also be implemented as a single optic, in particular as a common lens. The optics 18, 19 can be formed from a molded material. It is also conceivable to form a cover layer without a lens function in the recess 12 or on the housing cover 11 instead of optics. The cover layer seals the recess 12 and protects the transmitter 1 and the receiver 2 from environmental influences.

[0032] The Fig. 3, Fig. 4 to Fig. Figure 5 shows schematic representations of optimized planar configurations of transmitter 1 and receiver 2. Only the transparent transmission area 6 and the planar configuration of transmitter 1 and receiver area 3 are shown schematically.

[0033] Fig. Figure 3 shows a circular passage area 6 with a transmitter 1. The transmitter 1 has a smaller area than the receiving area 3. In this embodiment, the receiving area 3 is designed as a partial circle. Thus, a side contour 20 of the receiving area 3 has an approximately identical or the same shape as a boundary contour 21 of the passage area 6. In the illustrated embodiment, the receiving area 3 has a semicircular area. Depending on the chosen embodiment, the receiving area 3 can also have a smaller or larger portion than a semicircular area.

[0034] Further utilization of the area available for measurement, which is determined by the passage area 6, is in Fig. Figure 4 illustrates this embodiment. In this embodiment, the receiving surface 3 is U-shaped. The receiving surface 3 has two legs 22, 23, which are connected to each other via a connecting surface 24. The transmitter 1 is arranged between the legs 22, 23 of the receiving surface 3. In this embodiment as well, the receiving surface 3 has a partially semicircular side contour 20. The side contour 20 extends over more than a semicircular area and, for example, up to an almost three-quarter circle shape. The transmitter 1 has a base that is square or rectangular. Depending on the chosen embodiment, the transmitter 1 can also have a circular base.

[0035] One advantage of the described arrangement is that as much of the receiving space as possible is covered by the receiving surface 3. The receiving space is defined by the size and shape of the passage area 6. Depending on the chosen embodiment, the following can be considered in the various configurations: Fig. 3 and Fig. 4. The side contours 20 of the receiving surface 3 can be formed independently of the circular shape of the passage area 6. For example, in both embodiments, the receiving surface 3 can extend laterally beyond the passage area 6 and thus beyond the receiving space, and the receiving surface 3 can be rectangular or have a square outer contour. Thus, in these embodiments, the receiving surface 3 can have at least partially straight and semi-gonal side contours.

[0036] Fig. Figure 5 shows a further embodiment for cost-effective and efficient coverage of the receiving area with a receiving surface 3. In this embodiment, the receiving surface 3 is configured as three partial receiving surfaces 31, 32, 33. The first and third partial receiving surfaces 31, 33 are rectangular and form a first and a second leg 22, 23 of a U-shape, respectively. The second partial receiving surface 32 is also rectangular and is arranged between two ends of the first and third partial receiving surfaces 31, 33. The second partial receiving surface 32 forms a connecting surface 24 of the U-shape. Depending on the chosen embodiment, the second partial receiving surface 32 can also be square. The transmitter 1 is arranged between the first and third partial receiving surfaces 31, 33.Using the illustrated configuration of multiple partial reception areas 31, 32, 33, a cost-effective and efficient coverage of the reception area can be achieved. For example, the partial reception areas 31, 32, 33 can be configured as three photodiodes. Furthermore, depending on the chosen embodiment, a single segmented photodiode can be used to represent the first, second, and third partial reception areas 31, 32, 33.

[0037] An adapted sensor geometry allows for better utilization of the receiving area for the reflected measurement radiation. In particular, the measurement arrangement is designed to transmit and receive infrared signals. The larger receiving area, relative to the available transmission range 6 and the resulting reception area 17, results in higher sensitivity. Ideally, the area of ​​the transmitter 1 and the receiving area 3 of the receiver 2 cover the entire reception area 17.

[0038] The Fig. 6, Fig. 7, Fig. 8 to Fig. Figure 9 shows embodiments of a second measuring arrangement according to the invention, in which the transmitter 1 is arranged in the receiving space 17. Fig. Figure 6 shows a measuring arrangement 4 with a receiver 2 mounted on a carrier 8. A receiving surface 3 is formed on a top surface 25 of the receiver 2. A transmitter 1 is also arranged on or above the top surface 25 of the receiver 2. In the illustrated embodiment, the transmitter 1 is located directly on the top surface 25 of the receiver 2, i.e., on the top surface of the evaluation chip 7. The receiving surface 3 is annular around the transmitter 1. An inactive receiving surface 34 is annular around the transmitter 1 between the transmitter 1 and the receiving surface 3.

[0039] The inactive receiving area 34 is realized, for example, by omitting a receiving area 3, i.e., a photodiode. In another embodiment, the inactive receiving area 34 can be realized by an opaque cover covering the receiving area 3 in the region of the inactive receiving area 34. Furthermore, the inactive receiving area 34 can be realized by a sensor cover 35 covering the receiving area. The sensor cover is represented by a dotted line in Fig. Figure 6 illustrates this. In a further embodiment, the inactive receiving area 34 can be realized by deactivating the receiving area 3 in the region of the inactive receiving area 34 and not using it for evaluating the received reflected measurement radiation. The inactive receiving area 34, arranged in a ring around the transmitter 1, has the advantage that less interference radiation is received by the receiving area 3. An area adjacent to the transmitter 1 exhibits increased interference radiation, which represents unreflected measurement radiation.

[0040] Above transmitter 1 and receiver 2, a cover 5 with an opaque layer 9 is provided. The opaque layer 9 has an opening that forms a transmission area 6. The cover 5 is made of a material transparent to both the measurement radiation and the reflected measurement radiation. The opaque layer 9 is made of a material that is opaque to both the measurement radiation and the reflected measurement radiation. For example, the cover 5 can be made of glass, sapphire, or a plastic. Above the cover 5, the object 10, which is to be measured using the measurement radiation, is shown schematically. The measurement radiation 14 emitted by transmitter 1 can be reflected as interference radiation 37, for example, at an interface at a first optical element 18. Furthermore, the measurement radiation 14 can be reflected as interference radiation 37 at the cover 5.The interfering radiation 37 is thus reflected back to the transmitter 1 or the receiver 2 at a narrow angle relative to the direction of emission of the measuring radiation 14. As a result, the interfering radiation 37 either directly hits the transmitter 1 again or adjacent areas of the receiver 2. These adjacent areas are designed as an inactive receiving area 34 in order to reduce or prevent the reception of interfering radiation from the receiving area 3.

[0041] The inactive receiving surface 34 is configured such that reflected measurement radiation 15, which is reflected back from the object 10 towards the receiving surface 3 of the receiver 2, actually strikes an active receiving surface 3 or the receiving surface 3 itself. Depending on the chosen embodiment, the inactive receiving surface 34 and the receiving surface 3, or the entire receiver 2, can also be covered with a protective layer 36. The protective layer 36 can simultaneously provide optical guidance for the reflected measurement radiation 15. Furthermore, the first optics 18 and the protective layer 36, or the second optics 19, can be formed as a single optical element, particularly from a molded material.

[0042] Fig. Figure 7 shows a schematic top view of the arrangement of the Fig. 6. The cover 5 is shown transparently, and the shape of the passage area 6 is indicated by a dashed line. In the illustrated embodiment, the transmitter 1 has a rectangular base. Similarly, the inactive receiving surface 34 has a ring shape with a rectangular outer contour and a rectangular inner contour. The inactive receiving surface 34 can also be designed as a rectangular area above or on which the transmitter 1 is arranged. Furthermore, the receiving surface 3 has a ring shape with a rectangular outer contour and a rectangular inner contour. Depending on the chosen embodiment, the receiving surface 3 can also be an annular area. Likewise, the inactive receiving surface 34 can have an annular area. For example, the inactive receiving surface 34 can be designed as a circular disk above or on which the transmitter 1 is arranged.Furthermore, transmitter 1 can have a circular area as its base.

[0043] By stacking the transmitter and receiver on top of each other and preferably focusing the measurement radiation 14 using a first optic 18, the measurement arrangement can be reduced in terms of its surface area. A shadowing area of ​​the transmitter 1 on the receiving surface 3 can be reduced by appropriately shaping the size and / or form of the inactive receiving surface 34. Furthermore, areas 38 of the receiving area not covered by the receiving surface 3 can be used for the arrangement of additional sensors.

[0044] Fig. Figure 8 shows a schematic cross-section illustrating another example of the second design according to Fig. 6, however, in this embodiment the first optic 18, e.g. in the form of a lens, is arranged directly on the transmitter 1. By geometrically limiting the first optic 18 to the top surface of the transmitter 1, the reduction of interference radiation 37 that can reach the receiving surface 3 is reduced.

[0045] Fig. Figure 9 shows a further embodiment of the second embodiment of the measuring arrangement according to Fig. 6, in which a further reduction of the interference radiation 37 can be achieved. For this purpose, a holder 39 is provided for the first optic 18. In this embodiment, the holder 39 is designed as a housing that covers the transmitter 1 and positions the first optic 18 above the transmitter 1 in the direction of emission of the measurement radiation 14. The holder 39 surrounds the transmitter 1 and is arranged on the inactive receiving surface 34. The holder 39 positions the first optic 18, which is designed, for example, in the form of a lens, at a predetermined distance above the transmitter 1 in the direction of emission of the measurement radiation 14. This prevents any interference radiation from the first optic 18 from reaching the receiving surface 3. In addition, in this embodiment, the transmitter 1 is also arranged on the inactive receiving surface 34.

[0046] Depending on the chosen embodiment, the inactive receiving area 34 can also be realized by not using a portion of the receiving area 3 for evaluating the measurement signal. For example, the receiving area 3 can be configured as a photodiode with segmented regions. These segmented regions can also be configured as separate photodiodes. Thus, an inner region of the receiving area 3 can be configured as the first segmented region, representing an inactive receiving area 34 that is not used for evaluating the reflected measurement radiation 15.

[0047] Transmitter 1 can be a highly focused light source, particularly a laser diode such as a VCSEL. Further optimization and focusing of the measurement beam can be achieved through additional optics, such as a lens in the housing cover or a molded lens directly on the substrate. A highly focused measurement beam from the transmitter is advantageous for reducing interference. The substrate 8 can have a multilayer laminate, for example, made of FR4. Transmitter 1 could first be mounted onto the multilayer laminate. Receiver 2 could then be mounted onto the substrate 8. The transmitter and receiver unit can then be mounted onto a reflector. A cap can be applied to the substrate for mechanical protection. The cap can have at least one lens for the transmitter and / or a second lens for the receiver.

[0048] The Fig. 10, Fig. 11, Fig. 12 to Fig. Figure 13 shows embodiments of a third measuring arrangement or receiving surfaces of a receiver of the third measuring arrangement. Fig. Figure 10 shows a schematic side view of a transmitter 1 mounted on a carrier 8. A receiver 2 is positioned on the carrier 8 at a predetermined distance from the transmitter 1. The receiver 2 has a receiving surface 3 on the upper side of an evaluation chip 7. A cover 5 is located above the measuring arrangement 4. The transmitter 1 emits measuring radiation 14 towards an object 10 to be measured, which is located above the cover 5. The measuring radiation 14 can be reflected off the underside and the top side of the cover 5 and directed as interference radiation 37 towards the receiving surface 3. Thus, interference radiation 37 is received in a first area 41 of the receiving surface 3. Reflected measuring radiation 15 strikes the receiving surface 3 laterally next to the first area 41.

[0049] Fig. Figure 11 shows a schematic top view of the receiving surface 3 of the receiver 2. Fig. 10. The receiving area 3 has four strip-shaped segments 41, 42, 43, 44. The four segments 41, 42, 43, 44 form, for example, four receiving areas of a photodiode. Due to the segmented design of the photodiode 3, the four areas 41, 42, 43, 44 can be used independently of one another by the evaluation chip 7 to evaluate the received, reflected measurement radiation 15, depending on the selected evaluation method. Thus, depending on the measurement situation, at least one or more of the areas, in particular all areas 41, 42, 43, 44, can be excluded from the measurement of the reflected measurement radiation 15. Therefore, the evaluation chip 7 can individually adjust the evaluation of the segmented areas 41, 42, 43, 44. The four segmented areas 41, 42, 43, 44 can also be configured as four separate photodiodes.

[0050] Fig. Figure 12 shows a schematic top view of a further embodiment of a measuring arrangement 4 with a receiver 2 on which a transmitter 1 is arranged. Thus, this arrangement of the transmitter 1 and the receiver 2 essentially corresponds to the second measuring arrangement of the Fig. 6, Fig. 7, Fig. 8 to Fig. 9.

[0051] In this embodiment, the receiver 2 is configured with an evaluation chip 7, on the upper surface of which a receiving area 3 in the form of a segmented photodiode is formed. The photodiode has a first central region 41. In the illustrated embodiment, the first region 41 is rectangular. The first region 41 is surrounded by a second region 42 in an annular shape. The second region 42 is surrounded by a third region 43 in an annular shape. The third region 43 is surrounded by a fourth region 44 in an annular shape. The second, third, and fourth regions each have a rectangular inner contour and a rectangular outer contour. Depending on the chosen embodiment, the widths of the annular regions 42, 43, 44 can be the same or have different widths. In particular, the fourth and thus outer region 44 can have a greater width than the third and / or the second region 43, 42.

[0052] Depending on the chosen embodiment, the first area 41 may not be configured as a receiving area, and thus only the second, third, and fourth areas 42, 43, 44 may be configured as segmented photodiode areas. Depending on the measurement situation, at least one of the areas 41, 42, 43, 44 may not be considered when evaluating the received reflected measurement radiation 15.

[0053] Fig. Figure 13 shows an embodiment which is basically based on the structure of the arrangement of the transmitter and receiver of the Fig.12 corresponds to. A receiver 2 with an evaluation chip 7 is provided, on the upper side of which a receiving area 3 is formed. A transmitter 1 is arranged centrally in the receiving area 3. The transmitter 1 is arranged on a first circular area 41. The first circular area 41 is surrounded by a second annular area 42. The second annular area 42 is surrounded by a third annular area 43. Depending on the chosen embodiment, a fourth area 44 can also surround the third annular area 43. The individual areas 41, 42, 43, 44 can be designed as segmented areas of a segmented photodiode. Thus, depending on the chosen embodiment, at least one of the areas 41, 42, 43 can be disregarded during the evaluation of the received, reflected measurement radiation 15.Furthermore, depending on the chosen embodiment, the first area 41 can also be configured as an inactive receiving surface 34 or not as a receiving surface 3 at all. This configuration can be advantageous if too much interference radiation 37 is received in the first area 41 due to the existing measurement arrangement.

[0054] The receiving area 3 can be configured as a photodiode with segmented regions, whereby the segmented regions 41, 42, 43, 44 can be individually switched on or off for the evaluation of the reflected measurement radiation. With a small air gap to the cover 5, all segments 41, 42, 43, 44 could thus be used for evaluation. For a larger air gap between the transmitter and the cover 5, individual segments can be excluded from evaluation. As the air gap increases, more and more regions or segments of the photodiode are switched off. The regions or segments can be designed such that they have a smaller structure in the critical region than in the non-critical region. A critical region is characterized by a higher probability of interference radiation.This allows for precise adjustment to the measurement situation without losing too much sensitivity due to the decreasing receiving area. The segmentation, that is, the areas 41, 42, 43, 44 of the photodiode, can be implemented in any shape. For example, the areas can be rectangular, ring-shaped, or other forms.

[0055] By switching off selected segmented areas 41, 42, 43, 44 of the receiving area 3, crosstalk can be suppressed depending on the installation situation of the measuring arrangement. This allows the measuring arrangement to be operated in an optimized manner for a specific installation situation. The measuring arrangement 4 represents an optical sensor, with the sensor area being geometrically optimized to enable the smallest possible aperture in the housing.

[0056] The measuring device is suitable, for example, for recording a person's heart pulse and / or for determining blood composition, in particular oxygen concentration. Infrared radiation is used as the measuring radiation for this purpose. Furthermore, the measuring device can be used as a proximity sensor.

[0057] The invention has been illustrated and described in more detail with reference to preferred embodiments. However, the invention is not limited to the disclosed examples. Rather, other variations can be derived from them by a person skilled in the art without departing from the scope of protection of the invention. REFERENCE MARK LIST 1 transmitter 2 receivers 3 Reception area 4 Measuring setup 5 Cover 6 Passage area 7 Evaluation chip 8 carriers 9 shift 10 objects 11 Housing cover 12 Exclusion 13 Housing wall 14 Measurement radiation 15 reflected measurement radiation 16 broadcasting areas 17 Reception room 18 first optics 19 second optics 20 side contour 21 Side contour passage area 22 first thigh 23 second thigh 24 connecting surface 25 Top side receiver 31 first partial reception area 32 second partial reception area 33 third partial reception area 34 inactive reception areas 35 Sensor cover 36 protective layer 37 Interference radiation 38 Area 39 holders 41 first area 42 second area 43 third area 44 fourth area

Claims

[1] Measuring arrangement (4) with an optical transmitter (1) and an optical receiver (2), wherein the transmitter (1) is configured to emit electromagnetic measuring radiation (14) into a transmission chamber (16), wherein the receiver (2) is configured to receive measuring radiation (15) reflected from an object (10) in a receiving chamber (17), wherein means are provided to reduce the reception of interference radiation (37) by the receiver (2) that is not measurement radiation (15) reflected from the object (10), wherein the transmitter (1) is arranged in the receiving chamber (17), wherein the receiving chamber (17) adjoins the receiver (2) in a receiving area (3), wherein the transmitter (1) covers a partial area of ​​the receiving area (3) against reception of reflected measuring radiation (15), wherein an inactive area (34) is provided in the receiving area (3), wherein the inactive area (34) has at least a ring shape around the shaded partial area includes,wherein the receiver does not evaluate measurement radiation incident in the inactive area (34). [2] Arrangement according to claim 1, wherein no receiving area (3) is provided in the inactive area (34) or the receiving area (3) is covered or the receiving area (3) is deactivated. [3] Arrangement according to claim 1 or 2, wherein a lens (18) is provided in the transmission chamber (16) to focus the radiation onto a target area (a, object). [4] Arrangement according to claim 3, wherein the lens (18, 19) is formed from a mold material, and wherein the lens (18, 19) covers the transmitter (1) and at least partially the receiver (3). [5] Arrangement according to claim 3, wherein the lens (18) is held in a holder (39) at a distance from the transmitter (1), wherein the holder (39) is arranged on the receiving surface (3) or the receiver (2), wherein the holder (39) surrounds and covers the transmitter. [6] Arrangement according to one of the preceding claims, wherein the transmitter (1) is arranged on the receiver (2). [7] Arrangement according to one of the preceding claims, wherein the receiver (2) has a receiving area (3) arranged on an evaluation chip (7), wherein the receiving area (3) has a smaller area than the evaluation chip (7). [8] Arrangement according to one of the preceding claims, wherein a cover (5) is arranged at least partially in the transmitting space (16) and in the receiving space (17), wherein the cover (5) has a pass-through area (6), wherein the pass-through area (6) is transparent to the measurement radiation (14) and transparent to reflected measurement radiation (15), wherein the pass-through area (6) comprises at least partially the transmitting space (16) and at least partially the receiving space (18), and wherein the pass-through area (6) has a continuous surface.

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