Holographic Touch Screen

Components

• An interface to accept user touch input in the area where the Hologram is displayed. (Touch Screen)
• An optics system to generate the hologram.
• An LCD screen which acts as the object for the optical system.

Touch Screen

• Approach : A 7x7 grid area bordered by Infrared Transmitter/Receiver pairs which are used to determine the X and Y position of our finger. Analog Multiplexers to reduce input pins.
• Alternative : Detect the position of the finger via Image Processing.

Optics System

• Approach : Concave Mirror optics system requiring 2 concave mirrors with a hole in the centre of one of the mirrors.
• Alternative : Fresnel biprism approach used in modern automobiles.

LCD Screen

• We plan to implement a calculator hologram.
• Approach : A color LCD such as the one used in Nokia 6100 operated by Arduino, Rasberry Pi or a PC itself.

Touch Screen

• We completed a frame of IR sensors with Analog Multiplexing. As individual strips it worked well. Failed to give results when all put together.
• Changes :- We have modified the spatial arrangement of the sensors. This new approach needs lesser wiring, no multiplexing and produces better results. We have the strips soldered and ready.

Optics

• Visited IDC and got two plastic surfaces ready via the Plastic Studio.
• Waiting for the Mylar Sheets. Couldn't find Mylar sheets in the vicinity. Metallurgy dept. didn't have any idea about this material

LCD Screen

• Tried out a few combinations. Have settled for a 16x2 LCD display with static button pad. Purchased and ready to program.

Touch Screen

• Mechanical frame to support the sensor boards and align them well.

Optics

• Stick the reflective sheets and spatial arrangement of the system.

LCD Screen

• Program the 16x2 LCD to display results.

Touch Screen

• Go for an image processing based approach with camera modules.

Optics

• Hexagonal mirrors, polishing the surface ourselves.