Field device

Abstract

Field device (1) comprising a housing (3), at least one electronic component (5) arranged in the housing (3) for detecting a state of the field device (1), and at least one light source (7) for optically indicating the state, wherein the indication is readable outside the field device (1), wherein a light guide (9) is provided which interacts with the light source (7) in such a way that the indication is readable outside the field device (1), wherein the light guide (9) is designed and arranged to achieve a planar emission with a emission surface (A) perpendicular to a main emission direction of the light source (7) which is a multiple of an emission surface (A) of the light source (7), characterized in that the light guide (9) is essentially pot-shaped and designed as a cover (4) of the field device (1).

Description

[0001] The present invention relates to a field device according to the preamble of claim 1.

[0002] Various field devices are known from the prior art, comprising a housing, at least one electronic component arranged in the housing for detecting the state of the field device, and at least one light source for optically indicating the state, wherein the indication is readable outside the field device. An exemplary field device according to the prior art is described in Fig. 3 shown.

[0003] Fig. Figure 3 shows a field device 1 with a housing 3, which is closed with a cover 4. A sensor 15 is arranged in the housing 3, which is designed to convert a measured quantity into a measurement signal. An evaluation unit 16 is connected downstream of the sensor 15, which, in addition to evaluating the measurement signal, also detects the state of the sensor 15 and, if applicable, of the field device 1 itself. The state can include, for example, whether the measurement signal exceeds or falls below a limit value, whether the measuring device itself is functioning correctly, whether a permissible temperature is exceeded or fallen below, or the like. The corresponding state is then transmitted to an electronic component 5, which is also arranged in the housing 3. The electronic component 5 has a light source that is suitable for the optical indication of the state.For example, one or more LEDs can be used as the light source 7, which makes the status of the device visible externally, for example, in the form of a traffic light system with three different states. In such a traffic light system, for example, a green LED would be used for the state "device ready for operation", a yellow LED for the state "fault present", and a red LED for the state "device failed".

[0004] In the prior art, it is known to transmit this luminous information from the light source 7 by means of a light guide, starting from the electronic component 5 on which the light source 7 is arranged, through the cover 4, and to display it on the surface of the cover 4 or outside the field device 1. According to the prior art, a light guide may be provided which is designed such that it has a cross-section that essentially corresponds to the diameter of the light source in its main emission direction, so that emission with a radiating area A the size of the light source is achieved.

[0005] With these field devices known from the prior art, it is considered a disadvantage that readability is only guaranteed if an operator has direct access to the field device 1 and looks directly at the display.

[0006] Further prior art is known from DE 88 16 551 U1, DE 10 2008 047 422 A1, US 2009 / 0 225 530 A1, EP 2 177 881 A2 and DE 10 2005 025 670 A1.

[0007] The object of the present invention is to further develop a field device with a corresponding status indicator in such a way that universal readability is possible, especially from greater distances and under different viewing angles.

[0008] This problem is solved by a field device with the features of claim 1.

[0009] A field device according to the invention comprises a housing, at least one electronic component arranged in the housing for detecting a state of the field device, and at least one light source for optically indicating the state, wherein the indication is readable outside the field device, and wherein the light source is designed as a planar light source and / or a light guide is provided which interacts with the light source in such a way that the indication is readable outside the field device, wherein the light guide is designed and arranged in such a way that planar emission with a radiating surface perpendicular to a main emission direction of the light source can be achieved, which is a multiple of a radiating surface of the light source.

[0010] For the purposes of this application, a plate-shaped light guide shall be understood to be a light guide which has a significantly larger extent perpendicular to the main emission direction of the light source than in the direction of the main emission direction of the light source.

[0011] In the present application, a planar luminaire is understood to be a luminaire that has an extent perpendicular to its main emission direction which is a multiple of an extent in the direction of the main emission direction.

[0012] According to the present invention, a field device is provided in which, by generating a planar emission using a light guide, a significantly larger emission area is achieved compared to the prior art, and thus significantly improved readability is achieved.

[0013] Additionally, a flat light source can be provided. For example, a light-emitting film, in particular a light-emitting film made of organic light-emitting diodes (OLED film), can be used as a flat light source.

[0014] When the emitting area is increased by means of a light guide, this is preferably designed at least partially in a plate-like form, thereby achieving a corresponding emission characteristic for the field device. The use of such a light guide can be particularly advantageous when using a light-emitting diode (LED) as the light source, which may preferably be a multi-color LED.

[0015] To achieve optimal luminous efficacy, the optical fiber preferably has a single-coupling arrangement that interacts with the light source in such a way that light emitted by the light source is coupled into the optical fiber. Such a coupling arrangement can, for example, be designed as a conical recess in the optical fiber with an opening angle between 45° and 80°, preferably approximately 65°. Using such a coupling arrangement, light from a light-emitting diode can be coupled into a plate-shaped optical fiber particularly easily, the plate-shaped optical fiber being arranged perpendicular to the main emission direction of the light-emitting diode in this case.

[0016] A corresponding coupling arrangement can preferably be provided at the center of a plate-shaped and circular optical fiber.

[0017] To prevent the formation of a so-called hotspot—that is, an area with significantly increased light emission—in the coupling arrangement, it can be advantageous to apply a first coating to the outer surface of the light guide, i.e., on the side facing away from the light source, in an area opposite the coupling arrangement. Such a coating can be, for example, a paint or metallization, or, in the simplest case, a sticker applied to the light guide. This type of coating reduces direct light emission in this area and thus prevents the formation of the aforementioned hotspot.

[0018] According to the invention, the light guide is essentially cup-shaped, i.e., provided with a circumferential rim. The rim can preferably be arranged on the side of the coupling arrangement and extend essentially in the direction of the main emission direction of the light source.

[0019] By designing the light guide in this way, not only a planar but even a three-dimensional radiation effect is achieved.

[0020] According to the invention, the light guide of the present arrangement is designed as a cover of the field device, which makes it possible to integrate the light guide into existing field devices in a particularly advantageous way and, in particular, achieves further improved readability by illuminating the entire cover of the field device.

[0021] An improved luminous effect of the light guide can also be achieved by having a second coating and / or a structure on at least sections of the inner and / or outer surface of the light guide. Such a coating and / or structure can cause further reflections or refractions of the coupled light, resulting in an outward luminous effect.

[0022] The coating can be, for example, a metallization, a paint finish, or a sticker, and / or the texturing can be a satin finish on the light guide or grooves in the surface. A satin finish on the light guide, i.e., a slightly roughened surface, significantly improves light emission, resulting in a particularly good luminous effect.

[0023] The optical fiber is preferably made of polymethyl methacrylate, preferably satin-finished polymethyl methacrylate. This material is already known in the art and is characterized by good processability and durability, so that good and reproducible results can be achieved through its use.

[0024] The light guide and the light source are preferably matched to each other in such a way that the light guide, when the light source is in operation, essentially provides a luminance of at least 30 cd / m². 2 , especially between 30 cd / m² 2 and 150 cd / m² 2 , preferably of at least 50 cd / m² 2 , preferably of at least 75 cd / m² 2 and preferably of at least 100 cd / m² 2 with an area of ​​at least 20 cm 2 , preferably at least 40 cm 2 , especially 46 cm 2 , exhibits.

[0025] The status can be displayed, for example, as information about the operational readiness of the field device and / or information about a measured quantity.

[0026] The present invention is explained in detail below with reference to the accompanying figures. These show: Fig. 1 a cross-section through an electronic component such as may be used in a field device according to the invention, Fig. 2 a top view of the electronic component Fig. 1, and Fig. 3 a field device in accordance with the state of the art (already discussed).

[0027] Fig. Figure 1 shows a cross-section through an embodiment of an electronic component 5 as it can be used in a field device 1 according to the invention.

[0028] The electronic component 5 has a carrier 20, which can be made of plastic, for example, on which a circuit board 21 is arranged. A light source 7, which in this embodiment is a multicolor LED, is arranged centrally on the circuit board 21, which, like the carrier 20 in top view, is circular. Information about the state of the field device 1, for example its operating state, is supplied to the electronic component 5 via a connecting line. This information is converted in the electronic component 5 into a display signal, which is supplied to the light source 7, in this case the multicolor LED. Depending on the reported state, the multicolor LED is deactivated, for example, by emitting light in one of the colors green, yellow, or red, to signal the state externally. A main emission direction H of the light source 7 is defined in Fig. 1 is indicated by an arrow. In the present embodiment, the main emission direction H is essentially perpendicular to a surface defined by the circuit board 21. Perpendicular to the main emission direction H of the light source 7, a light guide 9, which is essentially plate-shaped in its first section, is arranged in front of the light source 7. In the present embodiment, the light guide 9 is also circular and has a circumferential rim 22 by means of which it is supported on the support 20. The circumferential rim 22 overlaps the circuit board 21 and the support 20, so that the light guide 9 is essentially cup-shaped overall, i.e., a hollow cylinder closed at one end.

[0029] In the present embodiment, the electronic component 5 is designed as a separate module which is connected to other modules by means of a bayonet fitting 23.

[0030] Directly opposite the light source 7, the light guide 9 has a coupling arrangement 11, which in the present embodiment is designed as a conical recess with an opening angle of approximately 65°. By providing such a coupling arrangement 11, the light emitted by the light source 7 is effectively coupled into the light guide 9 and distributed within it.

[0031] To prevent increased light emission in an area directly opposite the light source 7, the light guide 9 has a first coating 13 on its outer surface in this area, i.e., on the side facing away from the light source 7. This coating prevents the formation of a so-called hotspot, i.e., a point with increased light emission. This first coating 13 can be, for example, a paint, a metallization, or, in the simplest case, a sticker applied to the light guide 9.

[0032] To achieve improved light emission from the light guide 9, it further has a second coating 14 on its inner side, i.e., on the side facing the light source 7, which can also be designed as a coating or metallization. As a further possibility for improving light emission, an additional layer, preferably white, can also be provided on the inner side of the light guide 9, arranged at a small distance from it.

[0033] The aforementioned first and second coatings 13, 14 are also preferably white.

[0034] Fig. Figure 2 shows a top view of the electronic component 5. Fig. 1.

[0035] In Fig. Figure 2 clearly shows the circular shape of the light guide 9 and the central arrangement of the first coating 13. In the present embodiment, the first coating 13 has a diameter of approximately one-quarter of the total diameter and is designed as a coating. This ensures a largely homogeneous luminance across the entire surface of the light guide 9.

[0036] In the present embodiment, a radiation surface A is primarily defined by the surface of the light guide 9 visible in plan view. Additionally, the provision of the edge 22 achieves circumferential light emission. Overall, the radiation surface A is defined by the surface area A. Fig. 1 and Fig.In the embodiment shown in Figure 2, a significantly larger emission surface A is achieved compared to the emission surface of the light source 7, resulting in a significantly improved readability of the state of the field device 1 signaled by the light source 7.

[0037] As already indicated, the light guide 9 can not only be designed as an element of the electronic component 5, which is arranged in the housing 3, but can also be designed directly as a cover 4 of the field device 1. Reference symbol list 1 field device 3 cases 4 lids 5 Electronic component 7 light bulbs 9 optical fibers 11 Coupling arrangement 13 first coating 14 second coating 15 Sensor 16 Evaluation electronics 20 carriers 21 circuit boards 22 Rand 23 Bayonet lock A radiating surface H Main radiation direction

Claims

[1] Field device (1) comprising a housing (3), at least one electronic component (5) arranged in the housing (3) for detecting a state of the field device (1) and at least one light source (7) for optically indicating the state, wherein the indication is readable outside the field device (1), wherein a light guide (9) is provided which interacts with the light source (7) in such a way that the indication is readable outside the field device (1), wherein the light guide (9) is designed and arranged to achieve a planar emission with a emission area (A) perpendicular to a main emission direction of the light source (7) which is a multiple of an emission area (A) of the light source (7), characterized by , that the light guide (9) is essentially pot-shaped and designed as a lid (4) of the field device (1). [2] Field device (1) according to claim 1, characterized by , that the light source (7) is designed as a planar light source. [3] Field device(1) according to claim 1 or 2, characterized by , that the light source (7) is designed as a light-emitting film, preferably as an OLED film. [4] Field device (1) according to claim 1 or 2, characterized by , that the optical fiber (9) is formed in a plate-like form at least in sections. [5] Field device (1) according to any one of the preceding claims, characterized by , that the light source (7) is designed as a light-emitting diode, preferably as a multi-color light-emitting diode. [6] Field device (1) according to any one of the preceding claims, characterized by , that the light guide (9) has a coupling arrangement (11) which interacts with the light source (7) in such a way that light emitted by the light source (7) is coupled into the light guide (9). [7] Field device (1) according to claim 6, characterized by, that the coupling arrangement (11) is designed as a conical recess of the light guide (9) with an opening angle between 45° and 80°, preferably about 65°. [8] Field device (1) according to any one of the preceding claims, characterized by that the optical fiber (9) has a first coating (13) on its outer side in an area opposite the coupling arrangement (11). [9] Field device (1) according to any one of the preceding claims, characterized by that the optical fiber (9) has on its inner side, at least in sections, a second coating (14) and / or a structuring. [10] Field device (1) according to one of claims 8 or 9, characterized by that the coating is formed as a metallization, a paint finish or as a sticker and / or the structuring as a satin finish or grooves in a surface. [11] Field device (1) according to any one of the preceding claims, characterized by, that the optical fiber (9) is made of a polymethyl methacrylate, preferably of satin-finished polymethyl methacrylate. [12] Field device (1) according to any one of the preceding claims, characterized by , that the light guide (9) when the light source (7) is in operation essentially has a luminance of at least 30 cd / m² 2 , especially between 30 cd / m² 2 and 150 cd / m² 2 , preferably of at least 50 cd / m² 2 , preferably of at least 75 cd / m² 2 and preferably of at least 100 cd / m² 2 , with an area of ​​at least 20 cm 2 , preferably 40 cm 2 , especially 46 cm 2 exhibits. [13] Field device (1) according to any one of the preceding claims, characterized by , that the status displayed is information about the operational readiness of the field device (1) or information about a measured quantity. [14] Field device (1) according to any one of the preceding claims, characterized by , that the electronic component (5) is designed as a module which can be connected to other modules via a connection mechanism.

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