Digital Pen and Paper

Digital Pen and Paper

Pen and paper have a very significant role in our daily life. A world without these systems is unimaginable. We started the use of pen and paper, thousands of years ago. It is the most convenient method of recording information for future use. In a technology driven world of today, the traditional pen and paper are insufficient to meet our needs. This inadequacy has put forth a compulsion in developing an alternative to the traditional system, keeping in pace with the fast growing digital world, yet, compatibly resembling the traditional means.

Digital pen and paper are replaces the existing system and overcomes all the limitations of the older system. In this system, the user writes the data on a digital paper. The paper follows a technology that contains a special pattern of grid coordinates on the paper. This paper is created by printing some special pattern of grid coordinates of very small dots on ordinary paper that is perceived by the eye as a slight off-white color. The dots have a normal spacing of 0.3mm (0.01 inch).

Digital pen is an input device and looks like a normal pen. The pen can be activated by simply removing the cap and deactivated by replacing the cap. It can capture data from digital the paper.The received analog information obtained from paper, is converted to a digital format and the information is transmitted into another system.

Working principle

A digital pen can detect the data, which a user writes on the paper. The main component of a digital pen is a light source. LED is used as the light source. The light emitting from the LED is in the infrared frequency range.

An infrared LED is placed in the base of the digital pen. Users cannot see the light emitting from the LED, because human eyes cannot detect infrared rays. A camera is also placed at the base of the pen. This camera will help to capture the images from the paper depending on the pen’s movement in accordance with user’s writing.The light emitted from the LED source strikes on the paper and is then reflected back to the pen. A light detector is placed at base of the pen for detecting the reflected light. All these reflected light have different characteristics depending upon the user’s writing speed and style. A photoelectric cell is used as the light detector and it coverts the received light signal into corresponding electrical signal.

When the user writes something on a digital paper, the light from infrared LED strikes on the special pattern grid coordinates on the digital paper and is reflected back to the base of the pen based on the user’s writing movement. Then the received analog signal is converted into a digital signal and the signal is then decoded. Some information from decoded data is collected and stored in the memory for future use. The stored information can be loaded into a PC using either a USB cable or by some wireless technologies such as infrared or Bluetooth. The battery and memory of a digital pen is sufficient to complete 40 full pages of writings.