Time-of-flight Image Sensor with Simulated Distance Driver

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Solution Overview

Problem

The integration of a light source into mobile computing systems for time-of-flight imaging poses challenges such as high cost, packaging issues, and increased power consumption, which existing solutions have not adequately addressed.

Innovation Solution

An integrated image sensor and light source driver are combined in a single semiconductor chip package, allowing for the simulation of distances between the light source and an object by adjusting the relative phases and amplitudes of the light source drive signal and clock signals, thereby reducing the need for separate illuminator components and optimizing power usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a light source is integrated into mobile computing systems for time-of-flight imaging, then depth capturing capability is improved, but cost, packaging complexity, and power consumption increase

Engineering Contradiction:
Improvedepth capturing capabilityVSAvoidpackaging complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines the light source driver circuit and image sensor into a single integrated circuit package. The driver circuit generates light source drive signals that control an external light source, while the image sensor captures reflected light for depth measurement. This integration eliminates the need for separate packaging of light source and sensor components, reducing packaging complexity while maintaining time-of-flight imaging functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated circuit package serves multiple functions: the light source driver circuit controls light emission, the image sensor captures reflected light, and the system performs both traditional imaging and depth measurement operations. This multi-functionality allows mobile computing systems to achieve depth capturing capability without adding separate specialized components, thereby reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If a light source is integrated into mobile computing systems for time-of-flight imaging, then depth capturing capability is improved, but cost increases

Engineering Contradiction:
Improvedepth capturing capabilityVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

By integrating the light source driver circuit and image sensor into a single semiconductor chip package, the patent reduces the number of discrete components that need to be manufactured and assembled. This integration simplifies the manufacturing process, reduces component procurement costs, and enables volume production with lower per-unit costs compared to using separate light source and sensor modules.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If a light source is integrated into mobile computing systems for time-of-flight imaging, then depth capturing capability is improved, but power consumption increases

Engineering Contradiction:
Improvedepth capturing capabilityVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The light source driver circuit in the integrated package controls the light source to emit light in periodic pulses rather than continuously. This pulsed operation allows the image sensor to capture depth information at specific time intervals while consuming power only during active measurement periods, significantly reducing overall power consumption compared to continuous light emission.

Inventive Principle:
Principle #19Periodic action

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 solution provides a cost-effective, compact, and power-efficient means to achieve time-of-flight imaging capabilities, enhancing the depth capturing functionality in mobile devices while minimizing design and operational challenges.

Implementation Method 1

measures, for each of multiple pixels of an image sensor, the time between the emission of the light and the reception of its reflected image upon the sensor

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Implementation Method 2

emits light from a system onto an object and measures, for each of multiple pixels of an image sensor, the time between the emission of the light and the reception of its reflected image upon the sensor

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3238433B1Time-of-flight image sensor and light source driver having simulated distance capability
Publication Date: 2021.06.30 GOOGLE LLC
  • EP3238433B1 patent drawingFigure 1a
  • EP3238433B1 patent drawingFigure 1b
  • EP3238433B1 patent drawingFigure 2

AI summary

An apparatus is described that includes an image sensor and a light source driver circuit having configuration register space to receive information pertaining to a command to simulate a distance between a light source and an object that is different than an actual distance between the light source and the object.