Pointer Detection Using Orthogonal Code Multiplexing
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Solution Overview
Problem
Conventional cross point electrostatic coupling systems for pointer detection are inefficient, requiring a long time to detect a pointer at all cross points, making them unsuitable for practical use.
Innovation Solution
A pointer detection method that supplies signals based on orthogonal code strings with different phases simultaneously to multiple conductors, allowing for simultaneous detection of a pointer's presence and position across multiple cross points, enabling faster detection and supporting multiple-point detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If conventional cross point electrostatic coupling systems are used to detect pointers at all cross points, then detection coverage is complete, but detection time becomes excessively long
Solution Approach 1:
The patent applies periodic action by using orthogonal code strings with different phases that are supplied simultaneously to multiple conductors. Each conductor is assigned a specific phase of the orthogonal code, allowing the system to periodically sample and distinguish signals from different conductors through correlation detection, thereby achieving fast parallel detection without sacrificing accuracy
Solution Approach 2:
The patent changes the parameter of signal phase by assigning different phases of orthogonal code strings to different conductors. This parameter change enables the system to multiplex multiple detection channels simultaneously in the phase domain, dramatically reducing detection time while maintaining the ability to accurately identify pointer positions through phase correlation
2Speed
If signals are supplied sequentially to each conductor for pointer detection, then detection accuracy is maintained, but detection speed decreases
Solution Approach 1:
The patent merges multiple detection operations by supplying orthogonal code strings with different phases simultaneously to multiple conductors. The orthogonal properties of the code strings allow the system to combine multiple detection channels in the time domain while maintaining the ability to separate and accurately detect signals from each conductor through correlation processing
Solution Approach 2:
The patent uses periodic action through phase-modulated orthogonal code strings that are supplied simultaneously to multiple conductors. The periodic nature of the orthogonal codes with different phases enables the system to perform parallel detection across all conductors at once, achieving high detection speed without compromising position accuracy through phase correlation analysis
3Productivity
If multiple pointers are detected simultaneously using conventional methods, then multi-point detection capability is achieved, but the time required for complete detection increases significantly
Solution Approach 1:
The patent applies periodic action by using orthogonal code strings with different phases supplied simultaneously to multiple conductors, enabling the system to detect multiple pointers in parallel across all conductors at the same time. The periodic correlation detection process efficiently identifies all pointer positions within a single detection cycle, dramatically increasing throughput while reducing total detection time
Solution Approach 2:
The patent achieves universality by creating a detection system that can simultaneously handle multiple detection tasks - detecting pointers at any position on any conductor - using the same orthogonal code multiplexing mechanism. This multi-functional approach allows the system to adapt to various detection scenarios (single pointer, multiple pointers, different positions) without increasing detection time
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
This approach significantly reduces the time required for pointer detection, enabling faster and more efficient detection of multiple pointers or fingers, improving the system's practicality and accuracy.
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 a position of the pointer
Implementation Method 2
detects a variation of the electrostatic coupling state between a pointer and the electrode when the pointer approaches the electrode
Implementation Method 3
supplies signals based on orthogonal code strings with different phases simultaneously to multiple conductors, allowing for simultaneous detection of a pointer's presence and position
Data Source
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AI summary
A pointer detection apparatus includes a conductor pattern with first conductors disposed in a first direction and second conductors disposed in a second direction that crosses the first direction, and a code string signal production circuit for producing signals based on orthogonal code strings with phases different from each other and supplying the produced signals to the first conductors. The apparatus also includes a signal detection circuit connected to the second conductors for detecting a signal corresponding to a variation of electrostatic capacitance between the conductor pattern and a pointer, an analog to digital conversion (ADC) circuit for converting the signal output from the signal detection circuit into a digital signal comprising a word string of multiple bits, and a correlation detection circuit for determining correlation values between the code strings and the word string. The apparatus also includes a memory for storing correlation values successively output from the correlation detection circuit, wherein the pointer is detected based on the correlation values.