Electromagnetic handwriting input device and electromagnetic handwriting input method

Abstract

The invention discloses an electromagnetic handwriting input device and an electromagnetic handwriting input method, which are used for providing a handwriting input function. The electromagnetic handwriting input device comprises an electromagnetic pen and a digitizer, wherein the electromagnetic pen comprises a coil, a capacitor and a circuit board, can emit electromagnetic waves and is either an active pen-like input device with a power supply or a passive pen-like input device without the power supply; and the digitizer is provided with a plurality of antennae or coils arranged orthogonally for inducing the electromagnetic waves of the electromagnetic pen. The electromagnetic handwriting input method comprises the following steps: firstly, utilizing a controller of the digitizer to perform global scan so as to find out a coil position with a maximum induced potential and to find out two adjacent coil positions; performing optimal approximation by a Gaussian distribution function toobtain an accurate coordinate algorithm; and then calculating an accurate coordinate value of the electromagnetic pen with an inclined angle on the digitizer via the operation of a hardware circuit or the operation of a software program.

Description

technical field [0001] The invention relates to an electromagnetic handwriting input device and method, in particular to a handwriting input device and method with accurate positioning function. Background technique [0002] Computers, terminals, and electronic devices with similar functions need appropriate input devices to facilitate users to input commands, data, or click options on the display to control the operation of the computer. Commonly used input devices include contact input devices and non-contact input devices. input device. [0003] A digital board (Tablet or Digitizer) or an electromagnetic electronic whiteboard (White-board) needs to be equipped with an electromagnetic pen, and cooperate with the cursor or icon on the display device. The electromagnetic pen approaches or touches the digital board to select function icons, handwritten text or Drawing is a very convenient input device, especially writing and drawing functions, which are widely used in many ...

AI Technical Summary

Problems solved by technology

[0025] The disadvantage of the first-order approximate interpolation method in the prior art is that because the first-order approximation method is used to approximate the induced potential with an approximate Gaussian distribution, the error is relatively large, and the correction value needs to be stored in the memory for compensation. However, for a system with a larger number of coils, the The larger the required memory, the higher the cost and complexity of the hardware, which has an adverse effect on the reliability of the product. At the same time, the interaction induction between adjacent coils reduces the accuracy of the method.

[0026] The disadvantage of the quadratic approximation interpolation method in the prior art is that a large error is still caused by using the quadratic parabolic approximation method to approximate the induced potential with an approximate Gaussian distribution. Coil spacing, while limiting the electromagnetic pen not too close to the coil, to make up for the improper basis of the assumption

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