Illuminance and Proximity Sensor Single-Chip Integration

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Solution Overview

Problem

Existing image sensors in devices like mobile phones face challenges in integrating illuminance and proximity sensing into a single chip due to the need for different filters, such as IR cutoff and IR pass filters, which complicates the integration and increases chip size and production costs.

Innovation Solution

A dual-sensing unit system where one unit senses infrared and green light, and another unit filters visible light to sense infrared, with a control unit producing illuminance and proximity signals by subtracting difference values from the sensing signals, allowing both functions to be integrated onto a single chip.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If separate illuminance sensor with IR cutoff filter and proximity sensor with IR pass filter are used, then sensing accuracy is improved, but device complexity and chip integration difficulty increase

Engineering Contradiction:

Improvesensing accuracyVSAvoidchip integration difficulty

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the illuminance sensor and proximity sensor into a single integrated sensor chip. The sensor unit includes both green light sensing pixels and infrared sensing pixels with different filter structures, allowing both sensing functions to be performed by one integrated device rather than requiring separate components.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The sensor unit is designed to perform multiple sensing functions simultaneously. By incorporating both green light sensing capability (for illuminance measurement) and infrared sensing capability (for proximity measurement) within the same sensor structure, the device achieves multi-functionality that reduces overall system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If separate illuminance sensor and proximity sensor are used, then sensing performance is maintained, but chip size and production cost increase

Engineering Contradiction:

Improvesensing performanceVSAvoidchip size

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent merges the illuminance sensor and proximity sensor into a single integrated sensor chip. The sensor unit includes both green light sensing pixels and infrared sensing pixels with different filter structures, allowing both sensing functions to be performed by one integrated device rather than requiring separate components.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If separate illuminance sensor and proximity sensor are used, then sensing functions are reliable, but production cost increases

Engineering Contradiction:

Improvesensing functionsVSAvoidproduction cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

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 enables the integration of illuminance and proximity sensors onto a single chip, reducing chip size and production costs while enhancing price competitiveness by using a shared fabrication process for pixels and filters.

Implementation Method 1

a first filter under the first lens that passes the green light and the infrared rays only

Methodology Applied

Scientific EffectOptical filtering: Filter (optical)

Implementation Method 2

a second filter under the second lens that cuts off or filters the visible light and passes the infrared rays

Methodology Applied

Scientific EffectOptical filtering: Filter (optical)

Implementation Method 3

a first pixel under the first filter that senses the green light passing through the first filter

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 4

a first infrared pixel under the first pixel that senses the infrared rays passing through the first filter

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 5

a second infrared pixel under the second filter that senses the infrared ray passing through the second filter

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentUS9057644B2Illuminance and proximity sensor

Publication Date: 2015.06.16 DONGBU HITEK CO LTD

AI summary

An illuminance and proximity sensor includes a first sensing unit that senses infrared light and green light, and forwards a first sensing signal corresponding to a result of the sensing, a second sensing unit that filters visible light, senses the infrared light, and forwards a second sensing signal corresponding to a result of the sensing, and a control unit that produces an illuminance using a first difference value from subtracting the second sensing signal from the first sensing signal, and a proximity using a second difference value from subtracting the first difference value from the second sensing signal.