Abstract: A method for generating a haptic feedback on a display area operable by finger movements involves sensing a position of a finger on the display area and modulating a coefficient of friction between the finger and the display area is modulated depending on the position. The touchdown positions of two fingers are determined and the friction between each of the fingers and the display area is changed depending on a distance from the touchdown positions of the fingers simultaneously touching the surface.

Abstract: A method for detecting an operating input performed by a finger involves detecting various contact points of a contour of the finger using a sensor system on a sensor surface. The sensor system includes at least one transmitting unit for transmitting a signal to the finger and at least one receiving unit for receiving a signal reflected by the finger. A surface vibration is introduced into the sensor surface by at least one actuator, the surface vibration changes the frictional resistance between the finger and the sensor surface as a function of the changing contact points of the contour of the finger.

Abstract: An actuator is connected to an operating element of a manual user interface and outputs a haptic feedback signal to the user via the operating element. The operating element includes a sensor that detects a sensor signal generated by a manual input of the user as a reaction to the emitted feedback signal. The user's reaction time is determined. If the reaction time is shorter than a predetermined limit value, future haptic feedback signals are adjusted in such a way that their haptically perceptible intensity is reduced, and if the reaction time is greater than the predetermined limit value, future haptic feedback signals are changed in such a way that their haptically perceptible intensity is increased.

Abstract: An operating device to operate an adjustable seat of a motor vehicle having a carrier includes an operating element having a first surface directed towards an outer surface of the carrier, a second surface and at least one third surface adjacent to the first surface and the second surface. The operating device also includes a sensor for detecting a size of a force acting on the at least one third surface during the operating input and to generate a signal corresponding to the size of the detected force. The operating device also includes an evaluation device for generating a control signal by processing the signal corresponding to the size of the detected force, and an adjustment device to adjust the adjustable seat on the basis of the control signal.