Image Sensor Resolution Switch Circuit Using Charge Transmission

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Solution Overview

Problem

Conventional resolution switch circuits for contact image sensors suffer from noise, high production costs, and complex wiring structures, leading to signal uniformity issues and increased costs.

Innovation Solution

A resolution switch circuit that eliminates the need for additional switch circuits and transistors, using a switch capacitor to transmit signals as charges and a control unit to manage image gathering and signal combining units, thereby reducing noise and production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If additional resolution switch circuits are used to change resolution, then resolution switching capability is improved, but noise increases and signal uniformity deteriorates

Engineering Contradiction:

Improveresolution switching capabilityVSAvoidnoise

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes the additional resolution switch circuits from the system. By eliminating the sensing element-terminal resolution switch circuit and the shift register-terminal resolution switch circuit, the invention resolves the noise problem while maintaining resolution switching capability through a different approach using the existing shift register control mechanism.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention makes the existing shift register serve multiple functions: it both shifts the image signals and controls the resolution switching by generating output control signals. This eliminates the need for separate resolution switch circuits, thereby reducing noise while maintaining adaptability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If additional resolution switch circuits are used to change resolution, then resolution switching capability is improved, but device complexity and production costs increase

Engineering Contradiction:

Improveresolution switching capabilityVSAvoidwiring structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The shift register is designed to perform dual functions: signal shifting and resolution control. By generating output control signals based on control signals received from the control unit, it eliminates the need for separate resolution switch circuits and complex wiring, thereby reducing device complexity while maintaining resolution switching capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention merges the resolution control function with the existing shift register and control unit. The control unit generates control signals that are processed by the shift register to produce output control signals, combining multiple functions into existing circuit blocks and reducing overall system complexity.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If transistors are used in the optical signal converting unit as in conventional circuits, then signal conversion is achieved, but production costs increase

Engineering Contradiction:

Improvesignal conversion functionVSAvoidproduction cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The invention replaces expensive transistors with capacitors in the optical signal converting unit. Capacitors are generally cheaper and easier to manufacture than transistors, while still achieving the required signal conversion function through voltage signal generation based on accumulated charges.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention changes the signal conversion mechanism from transistor-based current/voltage conversion to capacitor-based voltage signal generation. The capacitor accumulates charges corresponding to the optical signal and generates a voltage signal, achieving the same functional outcome with different physical parameters and cheaper components.

Inventive Principle:

Principle #35Parameter changes

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 enhances signal uniformity, increases the signal/noise ratio, and lowers production costs by avoiding signal distortion and unnecessary circuit components.

Implementation Method 1

The circuit uses a switch capacitor (SC) to transmit signals in form of charges

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS7608809B2Switch circuit of an image sensor for changing resolution and a method thereof

Publication Date: 2009.10.27 DYNA IMAGE CORPORATION

AI summary

A resolution switch circuit for an image sensor uses a control unit to control a plurality of image gathering units to generate and store image signals. A resolution control unit controls a plurality of shift registers through the resolution control signals so that the shift registers control the image gathering units to output image signals. The signal combining unit is used to combine the image signals output from the image gathering units to achieve resolution change. Since the resolution switch circuit for the image sensor according to invention does not require additional resolution switch wiring, the affect of noise can be avoided and cost of the circuits can be reduced. The transmission of the image signals in the form of charges prevents any signal distortion due to resistance of wiring during transmission.