Patent · US Active

Camera shutter and position control thereof

US8547477B2 · kind B2 · utility

1Cited by

8References

23Claims

0Family size

Assignee

RPX Corporation · US

Inventors

Horst Knödgen · Hersbruck, DE
Frank Kronmuller · Kirchheim unter Teck, DE
Joachim Riexinger · Bad Boll, DE

Key dates

Filing date	Feb 5, 2010
Grant date	Oct 1, 2013
Priority date	—
Expiry date	Nov 11, 2031

Classification

Technology area (CPC H)Electricity
CPC primaryH02K41/0358
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

Systems and methods using the same to achieve a precise timing of a camera shutter, which can be used also for a controllable aperture, are disclosed. A bidirectional linear motor having two coils driving the shutter blades can also be used as a position sensor. A movable iron is driven dependent upon currents through the coils and as the iron moves, the inductance of both coils changes. The difference of inductance of both coils indicates the actual position of the iron. Since the movable iron is mechanically connected to the entirety of shutter blades the difference of inductance indicates the actual position of the shutter blades. A read-out circuit senses the difference of inductance of both coils, which is indicating the actual position, and a control loop is comparing the inductance difference signal with a target signal in order to control the current through the coils in a way that the shutter blades are moved quickly to their target position.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.