Switching Power Supply for Dermatologic Flash Lamp

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Solution Overview

Problem

Existing light-based dermatologic treatment devices rely on large capacitors for pulse forming circuits, leading to cumbersome, expensive, and inefficient devices, particularly in the consumer market where size, weight, and cost are significant concerns.

Innovation Solution

A switching power supply design that drives flash lamps to emit a sequence of small light pulses aligned with AC line waveform peaks, eliminating the need for substantial electrical energy from charged capacitors, thereby reducing device size, weight, and cost while ensuring therapeutic efficacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If large capacitors are used in pulse forming circuits to provide primary electrical energy for pulsing flash lamps, then sufficient light energy can be delivered for therapeutic effect, but device size, weight, and cost increase significantly

Engineering Contradiction:
Improvelight energy deliveryVSAvoiddevice weight
Core Design Contradiction:
Use of energy by moving objectVSWeight of stationary object

Solution Approach 1:

The patent applies periodic action by pulsing the flash lamp multiple times during each AC line cycle (e.g., 3-5 pulses per half-cycle) rather than using a single large capacitor discharge. The pulse-forming circuit generates a series of smaller voltage pulses that cumulatively deliver the required therapeutic energy (e.g., 10-20 Joules) to the flash lamp, eliminating the need for large energy-storing capacitors and reducing device weight and cost.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent changes the electrical parameters by using a high-voltage AC line source (e.g., 120V or 240V RMS) directly rectified and pulsed, rather than using low-voltage DC from capacitor discharge. The pulse-forming circuit switches the load at specific points in the AC waveform to generate the required pulse train, transforming the energy delivery mechanism from capacitive storage to direct AC line utilization, thereby reducing component size and weight.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If large capacitors are used in pulse forming circuits, then flash lamps can be pulsed to emit therapeutically effective light energy, but device cost increases

Engineering Contradiction:
Improvelight energy deliveryVSAvoiddevice cost
Core Design Contradiction:
Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The patent applies periodic action by pulsing the flash lamp multiple times during each AC line cycle (e.g., 3-5 pulses per half-cycle) rather than using a single large capacitor discharge. The pulse-forming circuit generates a series of smaller voltage pulses that cumulatively deliver the required therapeutic energy (e.g., 10-20 Joules) to the flash lamp, eliminating the need for large energy-storing capacitors and reducing device weight and cost.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies self-service by utilizing the AC line power source directly to provide the energy for pulsing the flash lamp, rather than requiring separate energy storage components. The circuit automatically synchronizes with the AC line waveform and uses its own switching elements to generate the pulse train, eliminating the need for expensive, large-capacity capacitors and simplifying the overall device architecture.

Inventive Principle:
Principle #25Self-service

3Use of energy by moving object

If large capacitors are used in pulse forming circuits, then flash lamps can be driven to emit sufficient light energy, but device complexity and bulk increase

Engineering Contradiction:
Improvelight energy deliveryVSAvoiddevice complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent applies periodic action by pulsing the flash lamp multiple times during each AC line cycle (e.g., 3-5 pulses per half-cycle) rather than using a single large capacitor discharge. The pulse-forming circuit generates a series of smaller voltage pulses that cumulatively deliver the required therapeutic energy (e.g., 10-20 Joules) to the flash lamp, eliminating the need for large energy-storing capacitors and reducing device weight and cost.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies the extraction principle by removing the large capacitor component from the pulse-forming circuit entirely. Instead of storing energy in a capacitor and then discharging it, the circuit extracts energy directly from the AC line source through controlled switching, simplifying the device architecture and reducing component count while maintaining therapeutic efficacy.

Inventive Principle:
Principle #2Taking out (Extraction)

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 enables efficient and effective light energy delivery for dermatologic treatments without the size, weight, and cost burdens of large capacitors, achieving desired cosmetic effects while maintaining safety and efficacy.

Implementation Method 1

drives the flash lamp to emit a sequence of light pulses

Methodology Applied
Scientific EffectLight emission from flash lamp: Luminescence

Implementation Method 2

an AC line voltage detector that dynamically generates an indication of when an AC line voltage exceeds a minimum operating voltage threshold

Methodology Applied
Scientific EffectVoltage detection: Electric Field

Implementation Method 3

sufficient light energy in aggregate to therapeutically heat target chromophores (e.g., melanin) in a skin region

Methodology Applied
Scientific EffectThermal heating: Heating

Data Source

PatentEP2398557B8Replaceable cartridge for light-based dermatologic treatment device
Publication Date: 2013.04.24 SHASER INC

AI summary

Switching power supplies made in accordance with the disclosed technology drive flash lamps of dermatologic treatment devices to emit a sequence of relatively small light pulses that are aligned with particular locations within the waveform of the AC line source. Such power supplies not only enable sufficient light energy in aggregate to therapeutically heat target chromophores in a skin region without causing undesired damage to surrounding tissue, but also provide the added benefit that the corresponding electrical energy need not be substantially drawn from any charged capacitor. The disclosed power supply further compensates for performance degradation of the flash lamps during their usable life, by modifying its operation based on predetermined values that are indicative of flash lamp aging/efficiency characteristics. The flash lamps and their associated stored values are preferably incorporated into a replaceable cartridge that facilitates user maintenance of the dermatologic treatment device.