the invention relates to an lcd circuit and a method for triggering at least one pixel of a liquid crystal display in order to optionally apply a voltage between a first and a second electrode , between which a layer of liquid crystals is arranged . the pixel switches into a non - transparent state when a voltage is applied whose value is greater than or equal to the value of a threshold voltage between the electrodes , a sensor voltage which changes across a sensor period being applied to at least one of the electrodes as said voltage or part of said voltage in order to generate a sensor signal for detecting an object approaching the pixel . also disclosed are an advantageous liquid crystal display encompassing such a circuit as well as an advantageous communication device comprising a first housing part that is provided with a display device , a second housing part , and an adjusting mechanism for moving the housing parts into a position in which the display device is located at a distance from the second housing part and moving the housing parts into a position in which the display device adjoins a bottom area of the second housing part , said bottom area being embodied by means of such a liquid crystal display .