Detection of very small displacement or close position is required as a result of recent developments in miniaturization and advances in the functionality of equipment.
We have developed the industry's smallest micro Hall element for precise position detection using a Hall sensor.
Here, we introduce an example of precise position detection achieved through use of a Hall element.
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Precise position detection with a Hall element |
Example: Using a Hall element with analog output makes it possible to detect the position of an object by resolving power in the order of a few micrometers for a stroke of 1 mm (moving distance).
Detection by resolving power in the order of a few micrometers is made possible by arranging two sensors and computing both outputs for a stroke of a few millimeters (moving distance).
In this case, the thermal characteristics of the two sensors are canceled, and linear output is obtained.
If a product with two built-in sensors (one package) is used, mounting error is not be an issue, and handling is easy.
Advantages of performing precise position detection using a Hall element
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Extended durability due to nonâ^'contact detection. |
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Because magnetism is detected, the device is more resistant to tiny particles of dirt, dust, or oil, compared to optical devices. |
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Miniaturization is possible. |
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Principle |
This principle enables a Hall element to achieve output proportional to the magnetic flux density.
By designing a layout where the magnetic flux density changes proportionally to the displacement of the measured object at the position of the Hall element, a Hall effect output proportional to the displacement can be obtained. |
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 Composition â^' 4 |
ãf» This example comprises one magnet and two Hall elements.
ãf» Same as Composition-3, the difference in outputs of two Hall elements becomes linear with the displacement.
ãf» Skewed magnet makes the difference in outputs of two Hall elements linear in wide range.
ãf» Large displacement can be covered by big outputs of Hall elements.
Furthermore, the thermal characteristics of output voltage are cancelled by dividing the difference in the outputs by the sum of the outputs.
 Feasible stroke and accuracy
Stroke: 5 to 10mm
Linearity:30 to 50um
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Recommended products for application |
Small size, high sensitivity, excellent linearity to the magnetic field and stability against ambient temperature, etc. are required for precise position detection applications, and our company offers a comprehensive choice of characteristics and package designs.
HQ series HG series
â^' High sensitivity and low current consumption are achieved simultaneously. Excellent thermal characteristics.
â^' Excellent thermal characteristics. Linear output.
â^' best suited to position detection of relatively long strokes and for portable, batteryâ^'powered equipment due to its high sensitivity
â^' recommended for position detection of relatively short strokes.
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Introduction of products > Hall element > Line-up > HQ series
Introduction of products > Hall element > Line-up > HG series
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Compositions and advice on product selection |
The best combination of magnet and sensor will differ according to displacement detected and required resolving power.
Please contact us about layouts, sizes, etc. |
List of applications |
Digital still cameras (hand movement compensating units, lens units, zooming mechanisms and AF mechanisms), etc.
Cellular phones (analog pointing devices), etc. |
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