In the physical sense, the representation of the virtual image is not a hologram, since neither monochromatic, coherent light is used here, nor does the image present itself depending on the viewing angle. Instead, a special material property is exploited here, which convergently bundles the diffusely emanating light rays at the location of the virtual image and thus creates the impression of a free-floating representation. The term "holography" is to be used for this.
The new terminal for holographic input puts an end to the risk of infection through touching. Completely without touching, just by marking virtual buttons in the air you operate the device - be it an elevator, a vending machine, a check-in counter or the menu in the restaurant. Get your ticket without typing the destination on the touchscreen interface and pay by credit card without having to type in the PIN.
The holographic image is created by directing the content of an image source, in this case a display, through a special holographic plate. In addition to angular deflection, convergent bundling of the rays takes place there, creating a virtual image floating freely in space.
The figure shows the arrangement necessary for the projection.
During integration, the optical laws for the beam path and reflections must be observed. Since the brightness decreases due to the conversion, a display with a high luminance of about 1,000 cd/m² must be used.
An infrared touch sensor is mounted below the virtual image. Its beam path is interrupted when the image is "touched". The interruption is evaluated as a touch event: single touch, multi-touch or as a gesture. The IR touch sensor is described here.
The effect is amazing and is immediately recognized by users, making the system suitable for use in public without the need to instruct the operator.
The holographic input can be used wherever it is necessary to avoid the transmission of viruses and bacteria through direct contact with button.
We are happy to demonstrate our demo system and advise on individual integration or the use of a readily available holographic input system.