Ultrasonic handwriting board of flat plate structure

Abstract

The invention provides an ultrasonic handwriting board of a flat plate structure. The ultrasonic handwriting board comprises an ultrasonic handwriting pen, at least three ultrasonic receivers which are respectively arranged on different positions on the edge of an isotropic hard handwriting bottom board, signal receiving and amplifying circuits and a data computing and processing unit which are matched with each other, a channel for calibrating ultrasonic signal emission time, and an element which can be arranged in the ultrasonic pen and is used for detecting handwriting pressure, wherein the ultrasonic pen comprises an ultrasonic emitter which is mechanically coupled with the tip of the pen made of a hard elastic material, and the tip of the pen can also adopt an amplitude transformer structure; and the ultrasonic handwriting pen can be also a wireless handwriting pen, and at least four ultrasonic receivers need to be arranged on the handwriting bottom board at this time. The ultrasonic handwriting board of the flat plate structure provided by the invention has the advantages of simple structure, wide use, low cost, high precision, long service life and the like; and in the event that the handwriting bottom board is made of a transparent material, the ultrasonic handwriting board can be directly arranged on the surfaces of various flat panel displays (FPDs) so as to be applied to a handwriting screen or tablet personal computer.

Description

technical field [0001] The invention relates to a handwriting input device for computers, which belongs to the technical field of acoustic signal generation and collection, in particular the application of acoustic technology in the technical field of computer data input. technical background [0002] Existing handwriting input technologies mainly include resistive film technology, capacitive sensing technology, electromagnetic induction technology, infrared optical technology, electromagnetic induction technology, spatial ultrasonic technology, and surface acoustic wave technology. The use of these technologies constitutes several basic handwriting tablet technical solutions, which satisfy many applications. But these technologies also have their own shortcomings, which limit their application in some fields. For example, in the application field of full-flat large-size handwriting tablet computers, the application of these technologies has been greatly restricted. Among ...

AI Technical Summary

Problems solved by technology

However, these technologies also have their own shortcomings, which limit their application in certain fields.

For example, in the application field of full-flat large-size handwriting tablet computers, the application of these technologies has been greatly restricted.

Among them, resistive film technology and inductive capacitance technology have the disadvantages of poor light transmittance, the palm or wrist cannot be pressed on the screen during application and are prone to fatigue, and resistive film technology also has the disadvantage of not being resistant to scratches; infrared optical technology, surface acoustic wave The problems existing in technology and space ultrasonic technology are: because the detection and sensing components are all located on the upper surface of the tablet, so when used on a display, there are sensors and even frames that need to protrude from the surface of the display screen, which cannot be completely flat; and the surface Acoustic technology, and the problem that ultrasonic reflection stripes are easily affected by dirt and cannot be used

But this solution is not a complete technical solution

First of all, the basis of this scheme is to assume that the speed of ultrasonic waves propagating in a finite-thickness, isotropic hard plate is certain, without taking into account the complexity of its propagation mode; secondly, this technical scheme is not sufficiently disclosed, and some The necessary technical details are not disclosed, because it is not practical

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