Cold Cathode Ionization Gauge Partition for Stable Discharge Start

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Solution Overview

Problem

Cold cathode ionization gauges face challenges in maintaining stable discharge characteristics over a wide pressure range and require frequent maintenance due to issues with discharge initiation and cathode deterioration.

Innovation Solution

A cold cathode ionization gauge design featuring a tubular cathode with a partitioned space, a light source emitting electromagnetic waves, and a configuration that allows these waves to enter the discharge space through gaps, ensuring efficient electron emission and reducing cathode particle adherence, thereby enhancing discharge stability and extending the gauge's lifespan.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a glow lamp is provided to irradiate the cathode with electromagnetic waves for initiating discharge, then discharge initiation is improved, but device complexity increases

Engineering Contradiction:
Improvedischarge initiationVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the light source, partition, and electromagnetic wave introduction function into an integrated structure. The partition serves dual purposes: it introduces electromagnetic waves from the light source into the discharge space while also serving as a structural component of the gauge head, thereby reducing overall device complexity while maintaining reliable discharge initiation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The partition structure performs multiple functions simultaneously: it acts as a barrier to separate spaces, serves as a pathway for electromagnetic wave introduction through its through-hole, and provides structural support for the light source arrangement. This multi-functionality reduces the need for separate components, simplifying the overall device design.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If high voltage is applied between cathode and anode to cause self-discharging, then pressure measurement function is achieved, but discharge stability deteriorates over wide pressure range

Engineering Contradiction:
Improvepressure measurementVSAvoiddischarge characteristics
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by using the light source to irradiate the cathode with electromagnetic waves before self-discharging occurs. This preliminary irradiation generates photoelectrons that facilitate the onset of discharge, ensuring stable discharge characteristics across a wide pressure range while maintaining accurate pressure measurement capabilities.

Inventive Principle:
Principle #10Preliminary action

3Loss of time

If cathode is irradiated with electromagnetic waves to generate photoelectrons, then discharge start time is reduced, but cathode particle adherence increases

Engineering Contradiction:
Improvedischarge start timeVSAvoidcathode particle adherence
Core Design Contradiction:
Loss of timeVSObject-generated harmful factors

Solution Approach 1:

The patent extracts the light source from the discharge space and positions it in a separate space, using the partition as an interface. This separation allows electromagnetic waves to be introduced into the discharge space through the partition's through-hole without placing the light source directly in the discharge environment, thereby reducing cathode particle adherence to the light source while maintaining effective photoelectron generation.

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 design achieves stable discharge characteristics over a wide pressure range, reduces maintenance needs, and prolongs the gauge's operational life by efficiently initiating discharges and preventing cathode particle accumulation.

Implementation Method 1

a light source, which is arranged in the partition, and is configured to emit an electromagnetic wave

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

applying high voltage between a cathode and an anode provided in a discharge space in a gauge head container to cause self-discharging so that gas is ionized

Methodology Applied
Scientific EffectGas ionization: Ionisation

Data Source

PatentEP3578943B1Cold cathode ionization gauge and cartridge for cold cathode ionization gauge
Publication Date: 2023.09.06 CANON ANELVA CORP
  • EP3578943B1 patent drawingFigure 1
  • EP3578943B1 patent drawingFigure 2
  • EP3578943B1 patent drawingFigure 3(a)~3(b)

AI summary

Provided are an excellent cold cathode ionization gauge and an excellent cold cathode ionization gauge cartridge. The cold cathode ionization gauge includes: an anode; a cathode, which has a tubular shape, and is arranged to surround the anode; a seal for sealing one opening of the cathode; a first member, which faces the seal inside the cathode, and has a through hole formed therein; a partition for partitioning a space surrounded by the cathode, the seal, and the first member into a first space that the first member faces and a second space that the seal faces; and a light source, which is arranged in the partition or the second space, and is configured to emit an electromagnetic wave, in which a gap is formed between at least part of an outer peripheral portion of the partition and the cathode.