Display device with energy-efficient screen

1. An electronic price and/or product display device ( 2 ), which comprises:

a reflective screen ( 21 ) for displaying information;

a signalling device ( 28 ) for signalling an internal state or an internal state change of the display device ( 2 ) by superimposing said state or state change in a visually perceptible manner in the direct view of the screen; and

wherein the signalling device ( 28 ) overlays only a portion of the information displayed by means of the screen with said light signal.

2. The display device ( 2 ) according to claim 1 , wherein the signalling device ( 28 ) comprises a light guide ( 23 ), which is attached or oriented with respect to the screen such that its predominant light dispersion direction extends parallel to the viewing area of the screen ( 21 ).

3. The display device ( 2 ) according to claim 2 , wherein the light guide ( 23 ) forms a component of the screen ( 21 ), covering the external viewing area of the screen, or is integrated into it, or forms said external viewing area.

4. The display device ( 2 ) according to claim 1 , wherein the signalling device ( 28 ) comprises one or more light sources ( 24 ), in particular LED or OLED, particularly RGB LED.

5. The display device ( 2 ) according to claim 1 , wherein the light source ( 24 ) is housed inside the housing of the display device ( 2 ), wherein the light generated with it is predominantly or substantially emitted or guided parallel to the viewing area of the screen or in a direction toward the viewing area.

6. The display device ( 2 ) according to claim 4 , wherein the signalling device ( 28 ) comprises a light guide ( 23 ), which is attached or oriented with respect to the screen such that its predominant light dispersion direction extends parallel to the viewing area of the screen ( 21 ) and wherein the light source ( 24 ) is optically coupled with the light guide ( 23 ) for the purpose of injecting the light generated by said light source.

7. The display device ( 2 ) according to claim 1 , wherein the signalling device ( 28 ) is designed for detecting a state or a state change as a result of a radio-based or light-based or line-based communication with an external device.

8. The display device ( 2 ) according to claim 7 , wherein the signalling device ( 28 ) comprises a first communication stage ( 12 ), which is designed for radio-based or light-based communication according to a time slot communication protocol or for line-bound communication, and is designed for detecting a signalling command in such communications as a trigger for signalling.

9. The display device ( 2 ) according to claim 7 , wherein the signalling device ( 28 ) is designed for detecting a change in the information to be displayed by means of the screen as a trigger for signalling.

10. The display device ( 2 ) according to claim 7 , wherein the signalling device ( 28 ) comprises a first communication stage ( 12 ), which is designed for radio-based or light-based communication according to a time slot communication protocol, and that the signalling device ( 28 ) is designed for autonomously detecting a communication problem, in particular a failure to synchronise with a base station ( 5 ), as a trigger for signalling.

11. The display device ( 2 ) according to claim 7 , wherein the signalling device ( 28 ) comprises a second communication stage ( 13 ), which is designed for radio-based communication according to a communication protocol designed for near-field communication, in particular the standardized NFC communication protocol, and the signalling device ( 28 ) is designed for detecting a signalling command in such communication as a trigger for signalling.

12. The display device ( 2 ) according to claim 1 , wherein the signalling device ( 28 ) comprises

a light signal-emitting device ( 23 , 24 ), which generates a visually perceptible light signal for signalling, and

a light signal control device ( 12 ; 13 ; 20 ; 12 , 20 ; 13 , 20 ) coupled or interacting with the light signal-emitting device and controlling the same, which controls the emitting of the light signal in dependence on said state or state change.

13. The display device ( 2 ) according to claim 1 , said device comprises an internal power supply, in particular realised by means of a rechargeable battery or a battery, or contacts for contacting a wired external power supply.

14. The display device ( 2 ) according to claim 1 , wherein the screen ( 21 ) alone or the screen together with the signalling device ( 28 ) realises a multi-coloured display.

15. The use of the display device ( 2 ) according to claim 1 as part of a path-signage system for indicating a path, or an emergency exit signage system for displaying a path to an emergency exit.

16. An electronic price and/or product display device ( 2 ), which comprises:

a reflective screen ( 21 ) for displacing information;

a signalling device ( 28 ) for signalling an internal state or an internal state change of the display device ( 2 ) by superimposing said state or state change in a visually perceptible manner in the direct view of the screen; and

wherein the signalling device ( 28 ) overlays the information reproduced by means of the screen with different light signals in specific zones.

17. An electronic rice and/or product display device ( 2 ) which comprises:

a reflective screen ( 21 ) for displaying information;

a signalling device ( 28 ) for signalling an internal state or an internal state change of the display device ( 2 ) by superimposing said state or state change in a visually perceptible manner in the direct view of the screen; and

wherein the signalling device ( 28 ) completely overlays the information reproduced by means of the screen with said light signal, in particular overlaying the entire display area of the screen.