DE102021114235A1 - Status display with means for guiding light and sensor with a status display - Google Patents

Abstract

The invention relates to a status display (10) for a sensor, having a base body (12) and at least one light source (18), the base body (12) having a first light exit area (22) and at least a second light exit area (26). Status display (10) should enable particularly energy-saving illumination or use the available energy or input power particularly effectively to display the status. For this purpose, the status display (10) has at least one means for light guidance (32), by means of which the light source (18) emitted light is directed to the first light exit area (22), to the second light exit area (26) or to the first light exit area (22) and the second light exit area (26).

Description

The invention relates to a status display for a sensor according to the preamble of patent claim 1. The invention also relates to a sensor with such a status display according to patent claim 10.

Various sensors for monitoring processes are known from the prior art. For example, the sensor can be a filling level sensor for continuously monitoring a filling level of bulk material or liquid in a container, or a limit level sensor for registering a minimum or maximum limit level of filling material in a container. The sensor can also be a pressure sensor or a temperature sensor in order to detect the pressure or the temperature in a container or a line.

Such sensors are regularly provided with a status display. The sensors generally include a housing, at least one electronic component arranged in the housing for detecting a condition or status of the sensor and at least one light source for optically displaying the status, the status being readable via a display unit outside the sensor. The status can include, for example, the measurement signal exceeding or falling below a limit value, the functionality of the measuring device itself, exceeding or falling below a permissible temperature, or the like.

In order for a user to be able to determine the status of the sensor as quickly as possible, the sensor has at least one light source that is designed to be suitable for optically displaying the status. One or more light-emitting diodes (LEDs) can be provided as illuminants, which make the status of the device visible to the outside, for example in the sense of a traffic light circuit with three different states. In such a traffic light circuit, for example, there can be a green LED for the status "device ready for operation", a yellow LED for the status "error present" and a red LED for the status "device failed".

Depending on the installation position of the sensor and the associated visibility of the status display, it may be desirable to only illuminate certain parts of the status display that can be seen by a user.

In particular, the aforementioned sensors are often field devices that determine measured values at a measuring point remote from the receiving device or a readout unit. Such field devices are often connected to higher-level units, for example control systems or control units. These higher-level units are used for process control, process visualization and/or process monitoring. The energy and/or signal transmission between the field device and higher-level units is often based on the known 4 mA to 20 mA standard, in which a 4 mA to 20 mA current loop or a two-wire line is formed between the field device and the higher-level unit. Alternatively, the sensor can also be designed as a self-sufficient field device that does not have a wired energy supply, but is only equipped with a battery or an accumulator. In this case, both of the above-mentioned energy supply options have a limited input power.

The underlying object of the invention is therefore to provide a status display for a sensor and a sensor with such a status display, which enable a particularly energy-saving illumination of the status display or which use the available energy or input power particularly effectively to display the status to use.

The object is achieved according to the invention with the features of the independent claims. Further practical embodiments and advantages are described in connection with the dependent claims.

A status display according to the invention for a sensor comprises a base body and at least one light source. The main body of the status display is in particular cylindrical and has an axial direction and a circumferential or radial direction. The axial direction also corresponds in particular to the main emission direction of the light source.

The at least one illuminant is in particular an LED or an OLED. If it should be provided that the status display should display more than two different statuses, the status display can also have a number of light sources and in particular a number of LEDs of different colors.

The base body has a first light exit area. The first light exit area is arranged in particular in the axial direction of the base body, with the axial direction also corresponding to the main emission direction of the light source. The light exit area is an area of the base body from which light can exit from the base body into the environment. present it is in particular a part of a top surface of the status display.

Furthermore, the base body has a second light exit area. The second light exit area extends in particular over a part of the peripheral surface of the base body, or in the case of a cylindrical base body over a part of the lateral surface. In particular, the second light exit area does not lie in the main emission direction of the lamp, but is arranged at an angle to the main emission direction. The second light exit area extends in particular over part and preferably over the entire circumference of the base body, so that the light from the illuminant can be seen all the way around the status display.

The status display has at least one means for light guidance, by means of which the light emitted by the lamp is directed either only or at least predominantly to the first light exit area, only or at least predominantly to the second light exit area or to the first light exit area and the second light exit areas.

The means for guiding the light make it possible to illuminate the status display as required. Depending on the installation position of the status display or the sensor, the light emitted by the light source can then be directed to the light exit area, which is probably or predominantly visible. This light exit area is then particularly bright. The energy provided is optimally used to illuminate the selected light exit areas of the sensor.

The base body has, in particular, a mirrored, funnel-shaped opening which is arranged between the illuminant and the first light exit area and by means of which light is directed to the first light exit area. The funnel widens in the direction of the first light exit surface. The light directed to the first light exit area is distributed as homogeneously as possible over the entire first light exit area by the wall surface of the mirrored, funnel-shaped opening. The light shines down into the small funnel opening and is distributed over a larger angle over the funnel-shaped wall surface.

Furthermore, in particular at least one mirrored light channel extending from the lighting means to the second light exit area is formed in the base body. A light channel is a channel delimited by at least two walls, with the light being reflected on the walls. In particular, the base body has a light channel that extends from the lighting means over the entire circumference and extends radially outwards to the second light exit area. The light channel is designed in particular as a disc-shaped intermediate space in the base body. In particular, the light channel has only one top surface and one bottom surface, each of which is mirrored. It is also conceivable that a plurality of light channels, separated from one another by side walls, extend outwards from the lighting means to the second light exit area. The light channel widens in a wedge shape, in particular towards its end, so that the light is distributed homogeneously over a larger, second light exit area.

In particular, a light guide is arranged in an end section of the light channel, the light guide homogeneously distributing the light emitted from the light channel over the second light exit surface extending on the peripheral surface of the base body. A light guide is an additional element which, for example, has a structured surface (matt) or even has a volume-scattering effect (milky) so that the light is distributed homogeneously. In particular, the light guide can be arranged in the wedge-shaped section of the light channel. Alternatively or in addition to this, a light guide can also be connected to the funnel-shaped opening.

It is also conceivable for a light guide to be arranged in the base body instead of the light channel, or for the light channel to also be formed circumferentially around the circumference of the base body in addition to the radial direction.

In a practical embodiment of the status display according to the invention, the means for guiding the light is a screen whose opening cross section can be adjusted and which, if necessary, prevents the propagation of radiation to the first light exit area. The screen is arranged in particular in the axial direction or in the main emission direction of the light source. The screen is preferably arranged in the area of the small cross section of the funnel-shaped opening facing the light source. When the aperture is open, light from the illuminant can pass through the aperture and reach the first light exit area in the axial direction (in the main emission direction). If the aperture is closed, the propagation of light in the direction of the first light exit area is prevented. The light propagates in the radial direction toward the second light exit area. The diaphragm can also be half open, so that the light propagates both in the direction of the first light exit area and in the direction of the second light exit area.

In order to realize the most efficient possible light guidance towards the second light exit area, the screen on the surface oriented towards the illuminant is designed in particular to be reflective. When the aperture is closed, the rays are reflected in the main emission direction of the lamp and contribute to the illumination of the second light exit area.

The opening cross-section of the screen can be infinitely adjustable in order to enable the most flexible possible adjustment of the illumination of the first light exit area and the second light exit area. In this case, the diaphragm can in particular be designed as an iris diaphragm.

In a further practical embodiment of a status display according to the invention, the screen is funnel-shaped when viewed in cross section. With the aperture open, the transmission of the light in the direction of the first light exit area is already improved by the aperture itself.

In a further practical embodiment of a status display according to the invention, an intelligent glass is used as a means for guiding the light, which, if required, prevents the propagation of radiation to the first light exit area. Smart glass is glass whose transparency or light transmission can be changed. For the present application, intelligent glasses that change their transparency when an electrical voltage is applied (electrochromism) are particularly suitable. In particular, this can be LC glass. LC glasses usually have a polymer liquid crystal film embedded between two panes of glass. Within the solid polymer are randomly oriented liquid crystal molecules. The incident light is scattered by them and the glass is opaque. When an electrical voltage is applied, the liquid crystal molecules arrange themselves and the glass becomes translucent. In this way, the light can be guided quickly and easily to the first light exit area, the second light exit area or both light exit areas by applying an electrical voltage.

Furthermore, an optical system with an axially adjustable focus in conjunction with a cover can be used as a means for guiding the light. In a retracted position of the optics, the light is focused in the axial direction and guided to the first light exit area. The further the optics are extended, the more the light is scattered in the circumferential direction and thus reaches the second light exit area. In order to achieve full deflection of the light in the circumferential direction, a cover is also provided, which completely shields the axial direction.

The invention also relates to a sensor with a status display as described above. The sensor is in particular a limit level sensor, a filling level sensor, a pressure sensor or a temperature sensor. The status display is used to indicate the status of the sensor, e.g. "sensor ready for operation", "error present" or "sensor failed".

• 1a eine erfindungsgemäße Statusanzeige in einer ersten Ausführungsform in einem Schnitt in einer perspektivischen Ansicht von schräg oben in einem ersten Betriebszustand,
• 1b die Statusanzeige aus 1a in einer perspektivischen Ansicht von schräg unten in dem ersten Betriebszustand,
• 2a die Statusanzeige aus 1a in einer perspektivischen Ansicht von schräg oben in einem zweiten Betriebszustand,
• 2b die Statusanzeige aus 2a in einer perspektivischen Ansicht von schräg unten in dem zweiten Betriebszustand,
• 3a die Statusanzeige aus 1a in einem Ausschnitt in einer perspektivischen Ansicht von schräg oben in einem dritten Betriebszustand,
• 3b die Statusanzeige aus 3a in einer perspektivischen Ansicht von schräg unten in dem dritten Betriebszustand,
• 4a - 4c eine erste Blende in einer Draufsicht in drei verschiedenen Zuständen mit korrespondierender perspektivischer Ansicht von schräg unten,
• 5a - 5c eine zweite Blende in einer Draufsicht in drei verschiedenen Zuständen mit korrespondierender perspektivischer Ansicht von schräg unten,
• 6a - 6c eine erfindungsgemäße Statusanzeige in einer zweiten Ausführungsform in einem Schnitt in drei verschiedenen Betriebszuständen.

Further embodiments and details are described below in connection with the figures. Show it:

• 1a a status display according to the invention in a first embodiment in a section in a perspective view obliquely from above in a first operating state,
• 1b the status display off 1a in a perspective view obliquely from below in the first operating state,
• 2a the status display off 1a in a perspective view obliquely from above in a second operating state,
• 2 B the status display off 2a in a perspective view obliquely from below in the second operating state,
• 3a the status display off 1a in a section in a perspective view obliquely from above in a third operating state,
• 3b the status display off 3a in a perspective view obliquely from below in the third operating state,
• 4a - 4c a first panel in a plan view in three different states with a corresponding perspective view from below,
• 5a - 5c a second screen in a plan view in three different states with a corresponding perspective view from below,
• 6a - 6c a status display according to the invention in a second embodiment in a section in three different operating states.

the 1 until 3 all relate to a first embodiment of a status display 10, the status display 10 being shown in a different operating state with different illumination.

The status display 10 has a base body 12 . The base body 12 is made of a light impermeable material. The base body 12 is cylindrical here and has an axial direction A, a radial or circumferential direction r and a top surface 14 and a lateral surface 16 .

A light source 18 is arranged on the base body 12 . In the embodiment shown, this is an LED with associated electronics 20.

The base body 12 also has a first light exit area 22 . The first light exit area 22 is arranged in the cover surface 14 in the axial direction of the base body 12 and here in the main emission direction of the light source 18 . Light from the illuminant 18 can radiate out of the base body 12 via the first light exit region 22 . The base body 12 also has a mirrored, funnel-shaped opening 24 in the axial direction. The funnel-shaped opening 24 widens upwards in the direction of the first light exit area 22.

A second light exit region 26 is formed on the peripheral surface or lateral surface 16 of the base body 12 . The second light exit area 26 extends circumferentially over the peripheral surface 16 of the base body 12. A mirrored light channel 28 extends in the radial direction from the light source 18 over the entire surface of the base body to the second light exit area 26. The light channel 28 is here as a disc-shaped intermediate space educated. The light channel 28 has a mirrored top surface and a mirrored bottom surface. The light channel 28 widens in a wedge shape in its end region. Furthermore, a light guide 30 is arranged in the end area here, which distributes the light in the circumferential direction over the entire second light exit area 26 .

In 1 a first operating state of the status display 10 is shown, the light of the illuminant 18 being guided exclusively to the first light exit area 22 . In 2 a second operating state of the status display 10 is shown, in which the light is directed exclusively to the second light exit area 26 . 3 FIG. 12 shows a third operating state, in which light is guided both to the first light exit area 22 and to the second light exit area 26.

Switching between these three operating states takes place via a means for light guidance 32. In the first embodiment shown, a screen 34 is used for this purpose.

Such an aperture 34 in a first form is in the 4a until 4c shown. The screen 34 is arranged at the lower, narrow end of the funnel-shaped opening 24 . If aperture 34 is open (cf. 4c ), then all or at least a majority of the light passes through the opening 24 and to the first light exit area 22 (cf. 1a and 1b ).

If the aperture 34 is closed (cf. 4a ), the propagation of the light in the axial direction towards the first light exit region 22 is not possible. The screen 34 is mirrored on its underside facing the illuminant 18 and the light is scattered into the light channel 28 and spreads out in it until it reaches the light guide 30 and the second light exit area 26 (cf. 2a and 2 B ).

In 3a and 3b the aperture 34 is only partially closed (cf. 4b ) and the light reaches both the first light exit area 22 and the second light exit area 26.

The opening cross-section of the screen 34 is infinitely variable, so that different ratios of illuminance between the first light exit area 22 and the second light exit area 26 can be set. Accordingly, the status display 10 can be illuminated as required.

Instead of a screen 34 whose cross section can be changed, an intelligent glass could also be arranged in the base body 12 . This would lead to the same operating conditions as in the 1 until 3 shown. Unlike a shutter, a smart glass does not open and close, but changes the transmission of light through the smart glass.

In the 5a until 5c a second form of diaphragm 34 is shown, wherein in the half section of FIG 5c it can be clearly seen that the screen 34 is funnel-shaped when viewed in cross section and thus supports the distribution of the light over the entire first light exit region 22 in the open state.

In the 6a until 6c a second embodiment of a status display 10 is shown. An optical system 36 with an axially adjustable focus is shown here as the means for guiding the light 32 . The optics 36 is in 6a shown in a retracted state, in which the light is focused in the direction of the first light exit area 22. In a partially extended state of the optics 36 (cf. 6b ) the light is no longer focused as strongly and part of the radiation reaches the second light exit area 26 via the light channel 28. If the optics 36, as in 6c shown, is fully extended, only a small part of the light reaches the first light exit area 22 conducted, the majority of the light is scattered via the light channel 28 in to the second light exit area 26.

In order to completely prevent radiation through the first light exit region 22 in the fully extended position of the optics 36, a cover is additionally provided, which can be positioned in the opening 24 (not shown here).

Reference List

10

status indicator

12

body

14

top surface

16

lateral surface

18

bulbs, LEDs

20

electronics

22

first light emission area

24

funnel-shaped opening

26

second light emission area

28

light channel

30

light guide

32

Means for guiding light

34

cover

36

optics

Claims (10)

Status display for a sensor, with a base body (12) and with at least one illuminant (18), the base body (12) having a first light exit area (22) and at least one second light exit area (26), characterized in that at least one means for light guide (32) is provided, by means of which the light emitted by the lamp (18) is guided to the first light exit area (22), to the second light exit area (26) or to the first light exit area (22) and the second light exit area (26). . Status display according to the preceding claim, characterized in that the base body (12) has a mirrored, funnel-shaped opening (24) arranged between the lighting means (18) and the first light exit region (22). Status display according to one of the preceding claims, characterized in that the base body (12) has at least one mirrored light channel (28) extending from the lighting means (18) to the second light exit region (26). Status display according to one of the two preceding claims, characterized in that a light guide (30) is arranged in an end region of the light channel (28) and/or a light guide is arranged on top of the funnel-shaped opening (24). Status display according to one of the preceding claims, characterized in that the means for guiding the light (32) is a screen (34) with an adjustable opening cross-section which, if required, prevents the propagation of radiation to the first light exit region (22). Status display according to the preceding claim, characterized in that the screen (34) is reflective on the surface oriented towards the lighting means (18). Status display according to one of the two preceding claims, characterized in that the screen (32) is funnel-shaped when viewed in cross-section. Status display according to one of the preceding claims, characterized in that an intelligent glass is used as the means for guiding the light (32), which prevents the propagation of radiation to the first light exit region (22) as required. Status display according to one of the preceding claims, characterized in that an optical system (36) with an axially adjustable focus and a cover serve as the means for guiding the light (32). Sensor with a status display (10) according to one of the above Claims 1 until 9 .

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