Laser sensor for detecting the presence of an object in continuous motion

A sensor for detecting the presence of a rotating object having an axis of rotation, comprising:

• a single light source remotely positioned away from the rotating object and at an oblique angle to the axis of rotation of the rotating object;
• means for focusing the light emitted by the light source on the rotating object;
• sensing means remotely positioned away from the rotating object and at an oblique angle to the axis of rotation of the rotating object for sensing light reflected from the object;
• and
• means for detecting light that is reflected from the rotating object that is intermittently detected at a frequency that is directly related to the frequency of rotation of the object.

A sensor for detecting the absence of a rotating drill bit having flutes, comprising:

• a single laser light source for generating laser light;
• means for focusing the laser light on the rotating drill bit, wherein said focusing means concentrates the laser light at or near the tip of the drill bit, enabling the evaluation of said tip of the drill bit at or near the surface of the material being drilled;
• means for sensing light reflected from the flutes of the rotating drill bit;
• and
• signal means connected to the sensing means for indicating the presence of the drill bit.

A sensor for detecting the presence of a rotating drill bit having a tip and at least one flute, comprising:

• a single energy source remotely positioned away from the drill bit and positioned at an oblique angle to the axis of rotation of the drill bit;
• means for focusing the energy from said energy source at or near the tip of the rotating drill bit when said rotating drill bit is positioned adjacent to an item intended to be drilled, enabling the condition of the tip of the drill bit to be evaluated at or near the surface of the item;
• means for sensing energy reflected from said flute of the rotating drill bit, said energy sensing means positioned at the substantially same oblique angle to the axis of rotation of the rotating drill bit;
• and
• first signal means connected to the energy sensing means for indicating the presence of said rotating drill bit.