Abstract: The present invention relates to a mulching rotary lawn mower blade and a method of mulching grass using a mulching rotary lawn mower blade. The mulching rotary lawn mower blade comprises a mounting section adapted to be attached to a lawn mower motor drive shaft and first and second sections extending respectively further outward from the mounting section and being respectively pitched upwardly and downwardly. First and second cutting surfaces are formed along at least a portion of at least one of the first and second surfaces. The first cutting surface is adapted to form grass clippings, while the second cutting surface has at least one cutout and is adapted to cut the grass clippings. The first cutting surface passes the grass clippings to the second cutting surface which recuts the grass clippings as the grass clippings pass through the cutout.

Abstract: An optical system (10) comprises a camera (11) having an imaging means that in use faces downwardly, and an optical assembly. The optical assembly includes a support (14) that extends outwardly from the camera (11) and which has a lumen therethrough to allow transmission of light through the support (14) to the imaging means of the camera (11). The assembly further includes an optical unit (16) mountable to the support (14) and movable relative thereto towards and away from the imaging means of the camera (11). The optical unit (16) includes at least one lens (17) and a mirror assembly ( 22, 23) adapted to reflect at least some light entering the unit (16) that is at approximately a right angle to the orientation of the camera (11), through the lens (17) and into the lumen of the support (14) to the imaging means. The system (10) can be mounted to a headpiece worn by a user, such as a surgeon.

Abstract: An optical system (10) comprises a camera (11) having an imaging means that in use faces downwardly, and an optical assembly. The optical assembly includes a support (14) that extends ouwardly from the camera (11) and which has a lumen therethrough to allow transmission of light through the support (14) to the imaging means of the camera (11). The assembly further includes an optical unit (16) mountable to the support (14) and movable relative thereto towards and away from the imaging means of the camera (11). The optical unit (16) includes at least one lens (17) and a mirror assembly (21, 22) adapted to reflect at least some light entering the unit (16) that is at approximately a right angle to the orientation of the camera (11), through the lens (17) and into the lumen of the support (14) to the imaging means. The system (10) can be mounted to a headpiece worn by a user, such as a surgeon.