Suction brush for use in vacuum cleaner and method of adjusting the height thereof

A suction brush for use in a vacuum cleaner, comprising:

• a brush casing having a suction opening to draw in air and a main air passage through which the air drawn in through the suction opening flows;
• a detecting unit disposed on the brush casing to detect a kind of a surface to be cleaned;
• a lifting unit to move a bottom surface of the brush casing close to and away from the surface to be cleaned;
• and
• a driving unit operated in response to a signal generated from the detecting unit and moving the lifting unit using air pressure generated by the air flowing through the main air passage, the driving unit having
• a conversion air passage in fluid communication with the main air passage;
• an air passage closing-up part configured to open and close up the conversion air passage so as to allow or prevent a suction force from being generated in or from the conversion air passage, the air passage closing-up part having
• a driving motor disposed on a lower casing of the brush casing configured to operate in response to the signal generated from the detecting unit;
• and
• an air passage closing-up plate connected to a driving axis of the driving motor configured to rotate between an open position and a closed position, the air passage closing-up plate being configured to open the conversion air passage part in the open position and close the conversion air passage part in the closed position;
• and
• an operating part configured to move the lifting unit when generation of the suction force is allowed or prevented in or from the conversion air passage.