Discharge Lamp Lighting Circuit for Stable Low Current Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing discharge lamp lighting systems face challenges in maintaining electric discharge at low lamp current levels, leading to premature extinguishment and requiring significant time delays for re-lighting, which affects heating processes in semiconductor manufacturing and annealing applications.
Innovation Solution
The discharge lamp lighting apparatus incorporates a main switching element, a simmer current supply circuit, and an electric discharge sequence control circuit that generates alternating ON and OFF states for the switching element, allowing for flexible control of lamp current waveforms and maintaining electric discharge through simmer current, even at low current levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the lamp current is reduced to minimize heating time and prevent substrate deformation, then the heating efficiency is improved, but the electric discharge becomes unstable and the lamp may extinguish
Solution Approach 1:
The patent applies periodic action by controlling the semiconductor switch to turn ON and OFF at least once after the flash lamp is triggered. This creates a controlled periodic current waveform that maintains the electric discharge stable even at low current levels, preventing lamp extinguishment while enabling rapid heating of the substrate
Solution Approach 2:
The patent implements dynamics by using a semiconductor switch that can dynamically adjust the lamp current waveform in real-time. The switch is controlled to create alternating ON and OFF states, allowing the system to adapt the current profile to maintain discharge stability during the heating process, rather than using a fixed current level
2Adaptability or versatility
If a semiconductor switch is used to control the lamp current waveform by turning ON and OFF, then the current waveform flexibility is improved, but the system complexity increases
Solution Approach 1:
The semiconductor switch serves multiple functions: it controls the lamp current waveform, maintains electric discharge stability, and enables flexible heating profiles. By making the switch multi-functional, the patent reduces the need for additional separate control mechanisms, thereby limiting the increase in system complexity while achieving waveform flexibility
3Use of energy by moving object
If the main capacitor voltage drops below the minimum discharge voltage, then the energy release is complete, but the electric discharge stops and the lamp goes out
Solution Approach 1:
The patent applies preliminary action by controlling the semiconductor switch to maintain the electric discharge even after the main capacitor voltage drops below the minimum discharge voltage. The switch continues to conduct current through the lamp, ensuring discharge continuity and preventing lamp extinguishment until the energy release is fully complete
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 enhances design flexibility and maintains electric discharge at low current levels, reducing the need for excessive margin settings and minimizing time delays for re-lighting, thereby improving the reliability and efficiency of substrate heating processes.
Implementation Method 1
a main capacitor (Cz) for accumulating electric charges for main electric discharge
Implementation Method 2
the high voltage is impressed to the starting electrode (Et), so that dielectric barrier discharge occurs in the electrical discharge space (Ds) of the lamp
Implementation Method 3
an increase rate of the lamp current after the start of the main discharge is controlled to fall within a predetermined range by usually inserting an inductor in a path connecting the main capacitor and the lamp
Implementation Method 4
a simmer current supply circuit that can pass simmer current through the discharge lamp
Data Source
AI summary
A discharge lamp lighting apparatus includes a capacitor, a charge circuit for charging the capacitor, a switching element, a gate driving circuit that controls ON and OFF states of the switching element, a simmer current supply circuit for passing simmer current through a discharge lamp, a starting circuit that impresses high voltage to a starting electrode, and an electric discharge sequence control circuit that generates the gate signal and the starting signal. When lighting the discharge lamp, a sequence of the gate signal corresponding to an alternating repetition of the ON and OFF states of the switching element is generated. Before outputting the starting signal, the switching element is ON as a stand-by state. Then the sequence starts when the starting signal is outputted.