Pointer Detection Using Simultaneous Code Supply
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Solution Overview
Problem
Conventional pointer detection apparatuses of the cross point electrostatic coupling system require a long time to detect the position of multiple pointers due to the sequential processing of each cross point, making them unsuitable for practical use.
Innovation Solution
A pointer detection apparatus that supplies multiple code strings simultaneously to transmission conductors, using a code supplying circuit and correlation value calculation codes constructed from a Hadamard matrix to determine correlation values, allowing for simultaneous detection of pointers across multiple cross points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If sequential processing of each cross point is used, then detection accuracy is maintained, but detection time becomes excessively long
Solution Approach 1:
The patent segments the detection process by dividing the conductor pattern into multiple regions and assigning different code strings to different transmission conductors. This allows parallel processing of multiple cross points simultaneously, reducing total detection time while maintaining accuracy through systematic correlation calculation of individual region signals
Solution Approach 2:
The patent employs periodic code strings (such as Hadamard codes or pseudo-random codes) that are supplied sequentially to different transmission conductors. By using these periodic, orthogonal code sequences and correlating the received signals with the known codes, the system can identify pointer positions across multiple cross points in a time-multiplexed manner, significantly reducing detection time compared to sequential scanning
2Productivity
If multiple code strings are supplied simultaneously to transmission conductors, then detection speed increases, but signal processing complexity increases
Solution Approach 1:
The patent introduces code strings as intermediary signals that are supplied to transmission conductors and used as reference patterns for correlation calculation. These code intermediaries enable the system to distinguish signals from different transmission conductors even when supplied simultaneously, reducing processing complexity by providing a systematic method for signal separation and identification
Solution Approach 2:
The patent changes the temporal parameters of the signals by using periodic code strings with specific correlation properties (such as orthogonal Hadamard codes or pseudo-random sequences). By carefully selecting code strings with low cross-correlation and high auto-correlation properties, the system can process multiple simultaneous signals with reduced complexity, as the mathematical properties of these codes simplify the separation and identification process
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables faster detection of pointers by reducing the time required for position detection across all cross points, allowing for real-time tracking of multiple pointers.
Implementation Method 1
a variation of the electrostatic coupling state between a sensor electrode and a pointer such as a finger or an electrostatic pen is detected in order to detect the position of the pointer
Data Source
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AI summary
A pointer detection apparatus and a pointer detection method of the cross point electrostatic coupling type are disclosed, by which a pointer on a conductor pattern can be detected at a higher speed. The pointer detection apparatus includes a conductor pattern, a spread code supplying circuit, a reception conductor selection circuit, an amplification circuit, an analog to digital conversion circuit, and a correlation value calculation circuit. The spread code supplying circuit supplies a plurality of spread codes at the same time. The correlation value calculation circuit determines correlation values between signals output from the analog to digital conversion circuit and the correlation calculation codes respectively corresponding to the spread codes. A pointer is detected based on the determined correlation values.