Annular variable capacitor and application thereof

Abstract

The invention relates to an annular variable capacitor and an application thereof, and belongs to the technical field of electromagnetic touch induction. The annular variable capacitor comprises a pen shell and a large-capacity pen refill assembled in the pen shell, and is characterized in that the tail end of the pen refill is closely contacted with an axial variable capacitor capable of expanding and contracting in the axial direction, and the axial variable capacitor is used for detecting axial pressure of the pen refill; an annular variable capacitor which is tightly nested between the outer side of the front half part of the pen refill and the inner side of the pen shell is used for detecting radial pressure of the pen refill; two electrodes of the annular variable capacitor are an inner electrode nested at the outer side of the pen refill and an outer electrode abutted inside the pen shell, a deformable elastic medium is arranged between the two electrodes, and the center of the inner electrode deviates when the pen refill moves along the radial direction; and the axial variable capacitor and the annular variable capacitor are arranged in parallel. According to the invention, both radial sensitivity detection and axial sensitivity detection are satisfied through a method of additionally arranging the annular variable capacitor at the outer side of the pen refill, so that replacement of a light small-capacity pen refill for a large-capacity pen refill is enabled to be possible in the field of electromagnetic touch induction.

Description

technical field [0001] The invention relates to an annular variable capacitor and its application, belonging to the technical field of electromagnetic touch sensing. Background technique [0002] The current stylus mainly utilizes electromagnetic touch sensing technology, endowed with functions such as signing, writing, and drawing on electronic devices. On the basis of the original stylus, a refill is added, so that it can write on paper and record handwriting at the same time. This touch ink pen technology has been gradually popularized and used in the education market. But the existing touch ink pen refill generally adopts the D type refill, such as figure 1 As shown, the refill diameter of this model is smaller and the length is shorter, so the ink capacity is small, so in the case of frequent use, there is a defect that the refill needs to be replaced more frequently, and it also increases the cost of using the touch ink pen . And replace the large-capacity refill, s...

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Problems solved by technology

But the existing touch ink pen refill generally adopts the D type refill, such as figure 1 As shown, the refill diameter of this model is smaller and the length is shorter, so the ink capacity is small, so in the case of frequent use, there is a defect that the refill needs to be replaced more frequently, and it al

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