System for controlling roller tube rotational speed for constant linear shade speed
US7281565B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 2004 |
| Grant date | Oct 16, 2007 |
| Priority date | — |
| Expiry date | Nov 16, 2024 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE06B2009/1746
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A system for controlling a roller shade having a roller tube windingly receiving a shade fabric varies roller tube rotational speed for constant linear shade speed. The desired linear shade speed, roller tube diameter and shade fabric thickness and length are stored in a memory for use by a microprocessor. Preferably, the roller tube rotational speed is varied by the microprocessor depending on shade position determined by signals from Hall effect sensors. The microprocessor maintains a counter number that is increased or decreased depending on direction of rotation. Based on the counter number, the microprocessor determines shade position and a corrected rotational speed for the desired linear shade speed. Preferably, the microprocessor controls roller tube rotational speed using a pulse width modulated signal. The system may be used to control first and second roller shades having roller tubes of differing diameters or shade fabrics of varying thicknesses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.