Display device having an optical display field

摘要

A first light source arranged behind a display field and configured to generate an elementary color or a secondary color from red, green and blue elementary colors for increasing safety of a display device having an optical display field, wherein the first light source is connected to an activation module which is configured to activate the first light source based on the desired color. A second light source is arranged behind the display field and configured to generate the elementary color or the secondary color from the red, green and blue elementary colors. The second light source is connected to the activation module which is configured to activate the second light source based on the desired color of the first light source, and a monitor is provided which is configured to identify an error or a fault on one of the light sources and to shutdown the faulty light source.

主权项

1. A Human Machine Interface (HMI) device for connection to a programmable logic controller, comprising:
a field bus interface connected to the programmable logic controller; an optical display field; a first light source arranged behind the optical display field of the HMI device and configured to generate a color to be generated as one of (i) an elementary color or (ii) a secondary color from elementary colors comprising red, green and blue; an activation module connected to the first light source of the HMI device and configured to activate the first light source in accordance with the color to be generated; a second light source arranged behind the optical display field of the HMI device and configured to generate the color to be generated, the second light source being connected to the activation module and the activation module of the HMI device being further configured to activate the second light source in accordance with the color to be generated; and a monitor configured to identify one of (i) an error and (ii) a fault on one of the first and second light sources and thereupon to shut down a faulty light source of the first and second light sources.