Magnetic Proximity Sensor

Simple SummaryContent extracted from patent full text and abstract with AI.

The patent describes a magnetic proximity sensor designed to detect the presence and measure the distance of magnetically permeable objects, particularly ferromagnetic materials. The sensor utilizes a magnetic field sensor (such as a GMR sensor) with a defined preferred axis and a magnetic field source (like a permanent magnet) arranged such that the magnetic field is normally perpendicular to this axis. When a permeable object approaches the sensor along the preferred axis, the magnetic field is distorted, creating a measurable component along the axis, allowing detection even through a shield. The design enables miniaturization and mass production using standard semiconductor processes.

Use CasesContent extracted from patent full text and abstract with AI.

• Industrial automation for detecting the proximity and position of metal components or machinery parts.
• Integration in magnetic bearings to monitor and control rotor-stator distance with high precision.
• Safety systems for machinery and vehicles to detect the presence or absence of metallic objects or barriers.
• Position sensing in robotics, such as arm or joint location feedback.
• Contactless switches or triggers for devices that require robust, non-optical object detection.
• Monitoring wear or alignment in mechanical systems by sensing changes in distance or presence of critical parts.

BenefitsContent extracted from patent full text and abstract with AI.

• Accurate detection and distance measurement of magnetically permeable objects, even through shields or enclosures.
• Insensitive to visual obstructions, making the sensor reliable in dirty or opaque environments.
• Reduced influence of hysteresis effects compared to other magnetic sensors, enabling more precise measurements.
• Low interaction forces between sensor and object, minimizing mechanical impact.
• High sensitivity, especially with GMR sensors, providing precise output at low magnetic field strengths.
• Enables miniaturization and low-cost mass production due to compatibility with semiconductor manufacturing techniques.
• Ability to shield against external magnetic interference, improving reliability in electromagnetically noisy environments.

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Patent Abstract

The invention relates to a magnetic proximity sensor for detecting a magnetically permeable object. It comprises at least one magnetic field sensor with a preferred axis and at least one magnetic field source which exposes said magnetic field sensor to a field component which is perpendicular to the preferred axis. According to the invention, the proximity sensor is designed to detect an object lying on the preferred axis of the magnetic field sensor, for example through a shield of a magnetically permeable material which surrounds the magnetic field sensor and the magnetic field source, and has a cutout as seen in the direction of the preferred axis of the magnetic field sensor. If a permeable object approaches, the magnetic field generated by the magnetic field source is distorted and obtains a component in the direction of the preferred axis of the magnetic field sensor, which can be registered by the magnetic field sensor. The proximity sensor can be miniaturized and can be produced using established semiconductor manufacturing methods.