Photoelectric Conversion Device With Alternating Pixel Column Read Directions

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Solution Overview

Problem

Conventional photoelectric conversion devices face challenges in reading voltage signals from pixels with high sensitivity due to the increased number of signal lines, which reduces the sensitivity of the voltage signals and makes it difficult to read the signals effectively.

Innovation Solution

The configuration of the photoelectric conversion device includes four pixel columns for different wavelength regions (red, green, blue, and near-infrared) with the direction of reading voltage signals from two pixel columns being different from the other two, reducing the number of signal lines between adjacent pixels and increasing the opening area for light reception, thereby enhancing sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the number of signal lines between adjacent pixels is increased to read voltage signals from all pixel columns, then the signal reading capability is improved, but the sensitivity of the voltage signals deteriorates due to increased signal line interference and noise

Engineering Contradiction:

Improvesignal reading capabilityVSAvoidvoltage signal sensitivity

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The pixel columns are divided into two groups with different reading directions. First pixel columns read in a first direction, while second pixel columns read in a second direction opposite to the first direction. This segmentation reduces the number of signal lines required between adjacent pixels, thereby improving voltage signal sensitivity while maintaining signal reading capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of reading all pixel columns in the same direction, the invention inverts the reading direction for different groups of pixel columns. Second pixel columns read in the opposite direction to first pixel columns, which reduces signal line interference and improves sensitivity.

Inventive Principle:

Principle #13The other way round (Inversion)

2Illumination intensity

If the opening area for light reception is increased to improve light sensitivity, then the light reception capability is improved, but the number of signal lines required increases, reducing the overall sensitivity

Engineering Contradiction:

Improvelight reception capabilityVSAvoidvoltage signal sensitivity

Core Design Contradiction:

Illumination intensityVSMeasurement precision

Solution Approach 1:

Pixel columns are segmented into two groups with different reading directions. This allows each pixel to have a larger opening area for light reception while the overall signal line density is reduced through the alternating reading pattern, maintaining voltage signal sensitivity.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If all pixel columns read voltage signals in the same direction, then the device structure is simplified, but the number of signal lines increases, reducing signal sensitivity

Engineering Contradiction:

Improvedevice structure simplicityVSAvoidvoltage signal sensitivity

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The pixel columns are divided into two groups that read in opposite directions. This segmentation maintains relatively simple device structure while reducing the number of signal lines between adjacent pixels, thereby improving voltage signal sensitivity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different reading directions are assigned to different groups of pixel columns, creating an asymmetric reading pattern. This asymmetric design reduces signal line interference compared to a symmetric same-direction reading approach, improving signal sensitivity.

Inventive Principle:

Principle #4Asymmetry

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 configuration allows for the reading of voltage signals with high sensitivity by reducing the number of signal lines and increasing the light reception area, ensuring equal sensitivity for each color and improving the overall signal processing efficiency.

Implementation Method 1

a first photoelectric conversion element configured to receive light of a first wavelength region and generate a signal charge

Methodology Applied

Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentUS11516423B2Photoelectric conversion device and image forming apparatus

Publication Date: 2022.11.29 RICOH CO LTD

AI summary

A photoelectric conversion device includes first to fourth pixel columns. Each of the first to fourth pixel columns includes a plurality of pixels arranged in a predetermined direction. Each of the plurality of pixels arranged in the first to fourth pixel columns includes a photoelectric conversion element configured to receive light of a wavelength region and generate a signal charge. Each of the plurality of pixels arranged in the first to fourth pixel columns further includes a circuit configured to convert the signal charge generated by the photoelectric conversion element into a voltage signal. Directions of reading the voltage signals from the first pixel column and the second pixel column are different from directions of reading the voltage signals from the third pixel column and the fourth pixel column.