Control method of input device

Abstract

The embodiment of the invention relates to a control method of an input device. The control method comprises the steps that a signal level judgment module determines whether an annular coil with the signal level larger than a first voltage threshold exists in a rough measurement feedback signal or not; if yes, the controller extracts a preset high voltage threshold value and a preset low voltage threshold value in the memory; the controller extracts a large voltage rough measurement coil and a small voltage rough measurement coil in the rough measurement feedback signals; the coil selection module is used for connecting the large-voltage rough measurement coils with the signal sending module in sequence according to the fine measurement instruction; the coil selection module is used for sequentially connecting the small-voltage rough measurement coils with the signal sending module through the phase reversal module; the signal receiving and processing module receives the accurate measurement feedback signal and sends the accurate measurement feedback signal to the controller; the signal level judgment module determines whether an annular coil of which the signal level is greater than a second voltage threshold exists in the accurate measurement feedback signal or not; if so, the controller extracts the maximum voltage fine coil and the minimum voltage fine coil in the fine feedback signal and generates an indication coordinate value.

Description

technical field [0001] The invention relates to a control method of an input device, in particular to a control method of an input device using electromagnetic induction. Background technique [0002] With the continuous improvement of the level of science and technology, computers are widely used in people's daily life. On the one hand, it is necessary to develop an output display system, and on the other hand, it is also necessary to develop an input device that transmits information from the user to the computer. In particular, a graphic input device that interacts with a computer through two-dimensional graphics, because the input device can enable users to input information using handwriting that people are used to, therefore, the graphic input device has become a necessary tool for real-time processing of handwritten characters and hand-drawn graphics. Especially in the fields of computer-aided design and computer-aided instruction. [0003] Among them, the input devi...

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Problems solved by technology

[0005] However, when the loop coil transmits a transmission signal with a high signal level, it is necessary to drive the transmission circuit with a high voltage or a large current, or to continuously transmit the signal for a long time, which may increase the size of the transmission circuit or increase the current consumption. In addition, In the case where a transmission signal is sent to the electromagnetic pen using a loop coil directly below the electromagnetic pen, if the size of the loop coil is relatively small, a transmission signal of a sufficiently high signal level cannot be transmitted to the electromagnetic pen, and at the same time, In the vicinity of the metal frame or baffle of the position detection device, the metal frame or baffle will also cover part of the signal sent from the nearby loop coil, resulting in the weakening of the signal that the electromagnetic pen can detect

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