Display device and device for measuring and / or monitoring a process variable

Abstract

The invention relates to a display device (1). A display component (2) displays information against backlight using electric energy. The display component (2) draws the electric energy for displaying the information from a first energy source (3) and draws the electric energy for the backlight from a second energy source (4). The second energy source (4) is in the form of a photovoltaic component. The invention also relates to a device for measuring and / or monitoring a process variable, comprising a display device (1).

Description

[0001] Display device and device for determining and / or monitoring a process variable

[0002] The invention relates to a display device. Furthermore, the invention relates to a device for determining and / or monitoring a process variable.

[0003] In devices for determining and / or monitoring process variables, which are also referred to as field devices in the field of process automation, it is known to use solar cells for power supply (see, for example, DE 10 2019 119 840 A1). It is also known that removable modules for displaying information or operating field devices are equipped with solar panels (cf. DE 10 2020 125 103 A1). In liquid crystal displays, if the solar cell is to serve as the sole power source, it is proposed to dispense with backlighting due to the high power consumption (see DE 101 37 588 A1). DE 695 30 157 T2 discloses different power sources for a computer.

[0004] However, it has been shown that, for example, in the case of direct sunlight, it is very important for the readability of a display unit that there is a backlight.

[0005] The invention is therefore based on the object of proposing a display device which functions reliably in a variety of situations, such as when the available electrical energy is limited or, preferably, even under difficult reading situations.

[0006] The invention solves the problem by means of a display device having a display component, a first energy source and a second energy source, wherein the display component is designed to display information in front of a - preferably controllable - background lighting using electrical energy, wherein the display component draws the electrical energy for displaying the information from the first energy source, wherein the display component draws the electrical energy for the background lighting - preferably at least or only - from the second energy source, and wherein the second energy source is designed as a photovoltaic component.

[0007] The display device according to the invention has at least one display component on which information can be displayed against a background lighting. The information includes, for example, data, e.g. measured values, or statements derived therefrom, e.g. whether a fill level has been reached or the state of a component coupled to the display device. Electrical energy is required both for displaying the information and for the background lighting, and this energy is obtained from two energy sources. A first energy source is assigned to the information display and at least or only a second energy source is assigned to the backlight. This makes it sufficient, for example, to ensure the energy supply via the first energy source in order to at least display the information. The functioning of the display device is thus always guaranteed, regardless of the second energy source.Conversely, this also allows, for example, the second energy source to be provided as a reversible or replaceable energy source in order to specifically switch on the second energy source when a backlight is needed.

[0008] By embodying the second energy source as a photovoltaic component, the electrical energy of the second energy source is generated through a type of energy harvesting. This means that the second energy source depends on whether there is sufficient light in the vicinity of the second energy source or the display device. Therefore, sufficient energy is available for the backlight precisely when the backlight ensures readability of the information despite the disruptive radiation.

[0009] In one embodiment, the electrical energy is drawn by coupling the structures or components of the display component responsible for the backlight (preferably predominantly, exclusively, or at least additionally) to the second energy source and receiving their energy (in whole or in part) therefrom. Alternatively or additionally, the backlight is controlled depending on the energy provided by the second energy source.

[0010] In one embodiment, the display device also serves to operate a component connected to it, so that it is a display and operating device.

[0011] In one embodiment, the display component is a color display.

[0012] In one embodiment, the display component is an LCD, LED, OLED or liquid crystal display unit.

[0013] One embodiment of the display device is that the display component draws the electrical energy for displaying the information only from the first energy source. In this embodiment, no energy is available from the second energy source for displaying the information. This means that the information is displayed in such a way that the energy from the first energy source is generally sufficient.

[0014] One embodiment provides that the display component draws the electrical power for the backlight from the first energy source and, additionally, from the second energy source. In this embodiment, the backlight is powered by the first and second energy sources. Therefore, continuous backlighting is possible—via the first energy source—and in cases where, for example, stronger backlighting is required due to direct sunlight, more power is available from the second energy source.

[0015] A further embodiment is that the display component draws the electrical energy for the backlighting predominantly from the second energy source. In this embodiment, the backlighting is predominantly dependent on the electrical energy provided by the second energy source. If the second energy source lacks energy, the backlighting is barely possible and, for example, only at low brightness. Conversely, if sufficient energy can be drawn from the second energy source, the background also illuminates, or is correspondingly bright.

[0016] In an alternative embodiment, the display component draws the electrical power for the backlight only from the second energy source. In this embodiment, a backlight is only available when the second energy source provides sufficient power.

[0017] In one embodiment, the backlight—e.g., the brightness—depends on the energy provided by the second energy source. For this embodiment, it is advantageous if the backlight can not only be activated or deactivated, but also controlled.

[0018] One embodiment of the display device provides that a control device, which is, for example, part of the display device, controls the background lighting as a function of electrical energy available from the second energy source.

[0019] In one embodiment, the second energy source serves solely to supply power to the backlight. The energy from the second energy source is thus only used to illuminate the background of the display component. The second energy source therefore does not serve, for example, other functions of the display device or other components coupled to the display device.

[0020] One embodiment of the display device is that the second energy source is at least partially optically transparent. This embodiment allows, for example, the second energy source to be arranged in front of the display component.

[0021] One embodiment of the display device provides that the second energy source and the display component are arranged relative to one another such that functionally effective sides are oriented in a common direction. The side of the display component on which the information is displayed and the background lighting is generated is located, for example, on the front of the display device. Preferably, the side via which the second energy source generates energy, e.g., photovoltaically, is also located on the front.

[0022] One embodiment of the display device is that the first energy source is designed as an energy interface. The energy interface allows, for example, the connection of a cable or a battery.

[0023] Furthermore, the invention solves the problem by a device for determining and / or monitoring at least one process variable, with a

[0024] Measuring device, a control device and a display device, wherein the measuring device is designed to determine or monitor a measured value of the process variable, wherein the control device is designed to output at least one item of information relating to the determined or monitored measured value via the display device, wherein the display device has a display component, a first energy source and a second energy source, wherein the display component is designed to display information in front of a - preferably controllable - background lighting using electrical energy, wherein the

[0025] Display component obtains the electrical energy for displaying the information from the first energy source, wherein the display component obtains the electrical energy for the backlight - at least, preferably or only - from the second energy source, and wherein the second energy source is designed as a photovoltaic component.

[0026] The invention is thus also achieved by a device for determining and / or monitoring at least one process variable (e.g., fill level, temperature, pressure, pH value, conductivity), which device has a display device. With regard to the display device, reference is made to the discussion of the preceding and following embodiments to avoid repetition. One embodiment of the device consists in that the display device is designed according to one of the preceding or following embodiments. The explanations also apply accordingly to the device.

[0027] The invention is explained in more detail with reference to the following figures.

[0028] Fig. 1 shows schematically a device for determining and / or monitoring a process variable and

[0029] Fig. 2 shows a circuit for supplying power to the display component.

[0030] Figure 1 shows a schematic diagram of a process automation measuring device. In the example shown, this is a measuring device for determining the fill level of a medium in a container by measuring the propagation time of radar signals. The measuring device 5 required for this (including all components required for the measurements and not shown here) is represented purely schematically by a horn antenna.

[0031] The measurement signals from measuring device 5 are received by a control device 6. The control device 6 displays the information associated with the signals via the display component 2 of the display device 1. The control device 6 is assigned to the display device 1 here, but can alternatively also belong to the measuring device 5. The display component 2 is, for example, a color display. To improve the readability of the actual information (indicated here by the speech bubble), the display component 2 allows control of the background lighting against which the information is displayed.

[0032] The display component 2 receives the energy required to display the information and the backlight from two energy sources: Firstly, there is a first energy source 3, which is designed here as an energy interface (e.g., for connection to a cable or a battery). Secondly, there is a second energy source 4, which is designed as a photoelectric component, i.e., a solar cell or solar panel. The display component 2 and the second energy source 4 are arranged relative to the housing 7 of the measuring device or display device 1 such that the active sides or surfaces - i.e., the display surface and the surface designed to receive photons - are each located on the front and are thus oriented in the same direction, namely forwards or toward the user.

[0033] The second energy source 4 is arranged here, for example, next to the display component 2. Alternatively, the second energy source 4 can be arranged around the display component 2 and, for example, consist of several subcomponents. Alternatively, the second energy source 4 is an at least partially transparent solar cell arranged in front of the display component 2.

[0034] The display component 2 uses the electrical energy from the first energy source 3 only for displaying the information itself and the electrical energy from the second energy source 4 only for the backlight. This is controlled here by the control device 6. Alternatively, the display component 2 can have two separate power supply paths for displaying the information and the backlight.

[0035] Thus, if no energy is available from the second energy source 4—e.g., due to darkness—the information itself can still be displayed. Conversely, if it is very bright, so that a lot of energy is required to illuminate the background to read the information, correspondingly more energy is available from the second energy source 4.

[0036] Fig. 2 shows an example of how the power supply to the display component is implemented via the two power sources 3, 4. The regulated current depends on the available power of the first power source 3 and is passed through the part of the display component that serves as the backlight (here represented by the light-emitting diode) and through the part that actually displays the information (here referred to as the display). The second power source 4, to which a diode is assigned here, supplies only the light-emitting diode of the backlight with electrical current. The purpose of the assigned diode is to ensure that the first power source 3 does not pass any power into the second power source 4 when the second power source 4 is not active. This is the case, for example, when the second power source 4 is designed as a solar cell, when the display device or the field device connected to it is in the dark.

[0037] List of reference symbols

[0038] 1 display device

[0039] 2 Display component 3 First energy source

[0040] 4 second energy source

[0041] 5 Measuring device

[0042] 6 Control device

[0043] 7 housings

Claims

Patent claims 1. Display device (1) comprising a display component (2), a first energy source (3) and a second energy source (4), wherein the display component (2) is designed to display information in front of a - preferably controllable - background lighting using electrical energy, wherein the display component (2) draws the electrical energy for displaying the information from the first energy source (3), wherein the display component (2) draws the electrical energy for the background lighting - preferably at least or only - from the second energy source (4), and wherein the second energy source (4) is designed as a photovoltaic component.

2. Display device (1) according to claim 1, wherein the display component (2) obtains the electrical energy for displaying the information only from the first energy source (3).

3. Display device (1) according to claim 1 or 2, wherein the display component (2) obtains the electrical energy for the backlight from the first energy source (3) and additionally from the second energy source (4).

4. Display device (1) according to claim 1 or 2, wherein the display component (2) draws the electrical energy for the backlight only from the second energy source (4).

5. Display device (1) according to one of claims 1 to 4, wherein a control device (6) controls the background lighting in dependence on an electrical energy available from the second energy source (4).

6. Display device (1) according to one of claims 1 to 5, wherein the second energy source (4) is at least partially optically transparent.

7. Display device (1) according to one of claims 1 to 6, wherein the second energy source (4) and the display component (2) are arranged relative to one another such that the functionally effective sides are oriented in a common direction.

8. Display device (1) according to one of claims 1 to 7, wherein the first energy source (3) is designed as an energy interface.

9. Device for determining and / or monitoring at least one process variable, with a measuring device (5), a control device (6) and a display device (1), wherein the measuring device (5) is designed to determine or monitor a measured value of the process variable, wherein the control device (6) is designed to display at least one item of information relating to the determined orto output a monitored measured value via the display device (1), wherein the display device (1) has a display component (2), a first energy source (3) and a second energy source (4), wherein the display component (2) is designed to display information in front of a - preferably controllable - background lighting using electrical energy, wherein the display component (2) draws the electrical energy for displaying the information from the first energy source (3), wherein the display component (2) draws the electrical energy for the background lighting - at least or only - from the second energy source (4), and wherein the second energy source (4) is designed as a photovoltaic component.

10. Device according to claim 9, wherein the display device (1) according to one of claims 2 to 8 is designed.

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