Patent ID: 7124803

Claim:
A venetian blind provided in a double glazing unit, which is mounted in a space defined by two sheets of glass, side frames, a top frame and a bottom frame, comprising: a blind body including a counterweight, a long shaft, a plurality of leaves, and a plurality of turning ropes, said turning ropes fitting over said long shaft and being connected to front and rear edges of said leaves respectively, and two ends of each turning rope being fixed to said counterweight; and a driving unit, comprising: a plurality of friction pulleys fitting over said long shaft, said counterweight and leaves being hung from said pulleys through said turning ropes, the number of the friction pulleys being equal to that of said turning ropes; a lifting pull line, one end of the lifting pull line being fixed to a sliding block and the other end thereof being fixed to said counterweight by passing over a guide pulley which is perpendicular to said long shaft and fixed inside the double glazing unit; a turning pulley provided on one end of said long shaft; a turning tension pulley fixed to said bottom frame of the double glazing unit and located below said turning pulley; an endless turning pull line winded around said turning pulley and turning tension pulley tightly, whose length being suitable for just tensioning between said turning pulley and turning tension pulley; said sliding block being fixed to said turning pull line; and two magnets, one of which being fixed to said sliding block and the other thereof being located outside the double glazing unit wherein movement of said outside magnet moves said sliding block.