Patent ID: 7971980

Claim:
An ink stick for use in an imaging device, the ink stick comprising: an ink stick body formed of a phase change ink material, an ink stick identifier associated with the ink stick, the ink stick identifier being a first ink stick identifier or a second ink stick identifier; and at least two reflection surfaces formed in the ink stick body, each reflection surface being configured to receive light from a light source associated with the reflection surface in an ink delivery system of a phase change ink imaging device, each reflection surface being configured to direct the light from the light source onto or away from a first light detector associated with the reflection surface in the ink delivery system or to direct the light from the light source onto or away from a second light detector based on correlation of the ink stick identifier with the at least two reflection surfaces to enable the first or the second light detector to generate an electrical signal having different signal characteristics indicative of the amount of light directed on either the first light detector or the second light detector by the reflection surface.