Projector Xenon Lamp Anode Shape for Stable Arc Position
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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, creating a more focused electric field that reduces arc movement and maintains lamp stability, thereby minimizing the likelihood of 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 magnetic field generation function is extracted from the external environment and integrated into the anode structure itself. The anode body with its specific geometric configuration (including the chip part and first part with different cross-sectional areas) acts as a magnetic field generator, eliminating the need for separate external magnetic field applying devices while maintaining arc stability.
Solution Approach 2:
The magnetic field generation function is merged with the anode structure. The anode serves dual purposes: as an electrode for electrical discharge and as a magnetic field generator through its specific geometry. This integration simplifies the overall device structure by combining multiple functions into a single component.
2Ease of manufacture
If the anode has a uniform cross-sectional area, then the manufacturing is simplified, but the arc position changes during start-up after long-term operation
Solution Approach 1:
The anode structure incorporates local quality variations through the chip part and first part with different cross-sectional areas. Rather than making the entire anode complex, only specific local regions (the chip part protruding toward the cathode and the first part with tapered shape) have modified geometries to generate the necessary magnetic field, while other portions maintain simpler forms for ease of manufacture.
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 configuration reduces the number of start-up attempts required, prolongs lamp life, and maintains illuminance, ensuring the lamp remains operational even after extended use.
Implementation Method 1
creating a more focused electric field that reduces arc movement and maintains lamp stability
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
Figure 1~2
Figure 3~4A
Figure 4B~5
AI summary
The xenon lamp (10) for a projector, the xenon lamp comprises a light-emitting tube (1) and an anode (3) and a cathode (2) 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 (21) and a chip part (22) 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 (22a) joined to the body part, the first part protruding toward the cathode and having a tapered shape; and a second part (22b) 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.