Pseudo Random Pulse Control for Distance Sensor Interference

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Solution Overview

Problem

Existing distance image measurement devices face challenges in achieving accurate measurement when multiple devices are used simultaneously due to interference from mixed pulsed light.

Innovation Solution

A distance image measurement device that generates pulsed light with controlled timing and charge transfer using a pseudo random number sequence, allowing for improved measurement accuracy by offsetting the influence of mixed pulsed light between devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple distance image measurement devices are used simultaneously with fixed timing, then device operation is simple and stable, but measurement accuracy deteriorates due to interference from mixed pulsed light

Engineering Contradiction:
Improvedistance measurement accuracyVSAvoidcontrol timing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the light emission timing and charge transfer timing variable rather than fixed. A pseudo-random number sequence is used to dynamically adjust the timing of light emission and corresponding charge transfer operations. This dynamic timing adjustment allows multiple devices to operate simultaneously without fixed timing conflicts, reducing interference from mixed pulsed light while maintaining operational simplicity through automated pseudo-random sequence control.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the timing parameter of light emission and charge transfer based on pseudo-random number sequences. By varying the timing parameters dynamically according to pre-determined pseudo-random patterns, the system achieves better measurement accuracy when multiple devices operate simultaneously, while the parameter changes are controlled through stored sequences rather than complex real-time calculations.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If light emission timing is changed to reduce interference, then measurement accuracy improves, but synchronization between light emission and charge transfer becomes more complex

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidtiming synchronization reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-generating and storing pseudo-random number sequences that determine the timing patterns. These sequences are prepared in advance and used to control both light emission and charge transfer operations. This preliminary preparation ensures that timing synchronization between light emission and charge transfer is maintained reliably, while still achieving variable timing to reduce interference from mixed pulsed light.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using the same pseudo-random number sequence to control both light emission timing and charge transfer timing. The system generates a pseudo-random sequence, uses it to determine light emission timing, and then uses the corresponding sequence to control charge transfer timing. This feedback mechanism ensures that the timing relationship between light emission and charge transfer remains synchronized while achieving variable timing patterns.

Inventive Principle:
Principle #23Feedback

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

The solution significantly enhances measurement accuracy by reducing errors caused by interference from external devices, enabling simultaneous operation of multiple devices without degrading distance calculation results.

Implementation Method 1

a photoelectric conversion region configured to convert light into charge

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentUS12140677B2Pseudo random number pulse control for distance measurement
Publication Date: 2024.11.12 NAT UNIV CORP SHIZUOKA UNIV
  • US12140677B2 patent drawing
  • US12140677B2 patent drawing
  • US12140677B2 patent drawing

AI summary

A distance image sensor includes a light source that generates pulsed light, a light source controller that controls the light source, a pixel circuit including a photoelectric conversion region, charge readout regions, and control electrodes, a charge transfer controller that sequentially applies control pulses to the control electrodes, a signal readout circuit that reads out detection signals of an amount of charge transferred to the charge readout regions and a distance calculator that repeatedly calculates a distance from a difference value between two amounts of charge on the basis of the signals, the light source controller changes generation timing of the pulsed light according to a pseudo random number, and the charge transfer controller changes timings of the application of two control pulses for transferring charge corresponding to the two amounts of charge according to the pseudo random number so that the timings are replaced with each other.