Optical Actuator Drive Circuit With Energy Feedback and Heat Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing drive devices for optical systems dissipate energy from actuators as thermal energy, leading to heating issues that can adversely affect adjacent components, and there is no efficient method to utilize this energy.

Innovation Solution

A drive device incorporating a switching amplifier, a filter unit with inductance, and a two-quadrant controller with feedback capability, allowing energy to be transported away from the actuator and either reused within the system or stored for later use, eliminating the need for thermal dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a switching amplifier is used to charge and discharge capacitive actuators with high capacitance, then the actuation speed and response time are improved, but thermal energy is generated that must be dissipated through cooling systems

Engineering Contradiction:
Improveactuation speedVSAvoidthermal energy
Core Design Contradiction:
SpeedVSTemperature

Solution Approach 1:

The patent converts the harmful thermal energy generated during actuator discharge into a beneficial resource by capturing it through the recovery circuit and storing it in the energy storage element. This recovered energy is then reused to charge actuators in subsequent cycles, transforming waste heat into useful electrical energy that improves system efficiency and reduces cooling requirements.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

Instead of dissipating the energy stored in capacitive actuators as waste heat during discharge, the patent implements a recovery mechanism that captures this energy through the switching amplifier and storage element. The recovered energy is retained and reused for charging subsequent actuators, eliminating the need to discard this valuable energy resource.

Inventive Principle:
Principle #34Discarding and recovering

2Ease of operation

If conventional discharge circuits are used to dissipate energy from actuators, then the actuators can be discharged, but the energy is wasted as thermal energy requiring cooling systems

Engineering Contradiction:
Improveactuator discharge capabilityVSAvoidenergy dissipation
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent transforms the energy that would normally be wasted as heat during actuator discharge into a recoverable resource. The switching amplifier captures the discharge energy and the storage element stores it for reuse, converting what was previously harmful waste heat into beneficial reused energy that reduces overall power consumption.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system implements an energy feedback loop where the discharge energy from actuators is captured and fed back into the system through the storage element. This feedback mechanism allows the system to reuse its own waste energy, creating a closed-loop energy management system that improves efficiency and reduces external power requirements.

Inventive Principle:
Principle #23Feedback

3Productivity

If switching amplifiers are used to drive a large number of capacitive actuators, then the productivity and throughput are improved, but the thermal load and cooling requirements increase

Engineering Contradiction:
ImprovethroughputVSAvoidthermal load
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent converts the thermal load generated by high-speed actuator operation into a beneficial resource. By capturing and storing the discharge energy from multiple actuators, the system recovers the thermal energy that would otherwise be wasted, and reuses it to charge subsequent actuators, thereby reducing the overall thermal load and cooling requirements while maintaining high productivity.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

Instead of allowing energy from multiple capacitive actuators to be dissipated as waste heat during rapid discharge operations, the patent implements a recovery system that captures this energy through the switching amplifier and storage element. The recovered energy is reused for charging subsequent actuators, eliminating the waste and reducing the thermal load associated with high-speed operation.

Inventive Principle:
Principle #34Discarding and recovering

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 reduces the need for extensive cooling, minimizes power loss, and enables the reuse of energy, improving the efficiency and reducing thermal stress on adjacent components.

Implementation Method 1

a two-quadrant controller (140) with feedback capability coupled between the providing unit (130) and the switching amplifier (110)... energy can be transported away from the actuator during the discharging process of the actuator... the energy transported away can be utilized again on account of the feedback capability

Methodology Applied
Scientific EffectEnergy feedback: Feedback

Implementation Method 2

a switching amplifier (110) for generating an amplified signal depending on a modulation signal... Switching amplifiers constitute an efficient realization for driving optical systems in order to charge and discharge a large number of capacitive actuators with high capacitance

Methodology Applied
Scientific EffectSwitching amplification:

Implementation Method 3

a filter unit (120) connected between the actuator (200) and the switching amplifier (110) and having at least one inductance... minimizes power loss... reduces the need for extensive cooling

Methodology Applied
Scientific EffectInductive filtering: Filter (electronic)

Data Source

PatentEP4140031B1Drive device, optical system and lithography apparatus
Publication Date: 2025.10.15 CARL ZEISS SMT GMBH
  • EP4140031B1 patent drawingFigure 1
  • EP4140031B1 patent drawingFigure 2
  • EP4140031B1 patent drawingFigure 3

AI summary

A drive device (100) for driving an actuator (200) of an optical system (300), comprising a switching amplifier (110) for generating an amplified signal (aPWM) depending on a modulation signal,a filter unit (120) connected between the actuator (200) and the switching amplifier (110) and having at least one inductance (121),a providing unit (130) for providing a supply voltage, and a two-quadrant controller (140) having feedback capability coupled between the providing unit (130) and the switching amplifier (110).