Projector Xenon Lamp Anode Geometry for Arc Position Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Xenon lamps used in projectors tend to go out during long-term operation due to arc position changes caused by cathode wear, leading to increased voltage requirements and potential lamp failure.
Innovation Solution
The xenon lamp design features a specific anode shape with a tapered chip part and a second part having a distinct angle of inclination, which creates a more focused electric field, reducing the likelihood of arc position changes and maintaining illuminance, thereby preventing lamp failure during start-up.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a magnetic field is applied from outside the light-emitting tube to reduce arc position change, then the arc stability is improved, but the device structure becomes complicated
Solution Approach 1:
The invention merges the magnetic field generation function with the anode structure by incorporating a magnet inside the light-emitting tube. The anode serves dual purposes: as an electrode and as a holder for the magnet, eliminating the need for separate external magnetic field generation devices and simplifying the overall structure while maintaining arc stability
Solution Approach 2:
The invention introduces a magnet as an intermediary element within the light-emitting tube that generates a magnetic field to counteract gas convection effects on the arc. This intermediary component mediates between the gas convection force and the arc, stabilizing the arc position without requiring complex external control systems
2Reliability
If the anode has a complex shape with chip part and tapered first part, then the arc position stability is improved, but the manufacturing precision requirement increases
Solution Approach 1:
The anode design applies local quality by creating specific geometric features (chip part and tapered first part) at particular locations to generate desired electric field distributions. The chip part protrudes toward the cathode to create a localized electric field enhancement, while the tapered first part gradually transitions the field distribution, stabilizing the arc position through localized geometric modifications rather than requiring precision across the entire anode surface
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 design reduces the frequency of starting actions, prolongs lamp life, and ensures swift operation, while maintaining satisfactory illuminance even after extended use.
Implementation Method 1
the shape of the second part satisfies the following relationships (1) and (2)... creates a more focused electric field, reducing the likelihood of arc position changes
Implementation Method 2
Xenon gas inside the light-emitting tube 81 is circulated by convection due to heat, and the arc A1 is subject to force in a Z direction caused by this convection
Implementation Method 3
By this starting voltage, dielectric breakdown occurs between both electrodes, an electric current called an inrush current flows, and an arc A1 is formed
Data Source
AI summary
The xenon lamp for a projector, the xenon lamp comprises a light-emitting tube and an anode and a cathode that are arranged inside the light-emitting tube so as to face each other through a gap in a first direction, the anode including: a body part and a chip part whose cross-sectional area cut along a first plane orthogonal to the first direction is smaller than the cross-sectional area of the body part, the chip part including: a first part joined to the body part, the first part protruding toward the cathode and having a tapered shape; and a second part joined to the first part, the second part protruding toward the cathode and having a shape such that an angle of inclination of an outer profile of the second part differs from an angle of inclination of an outer profile of the first part.