Patent ID: 8657425

Claim:
An ink cartridge comprising: a case comprising an ink chamber formed in the case, wherein the ink chamber is configured to store ink therein; an ink supply opening formed in the case, wherein the ink supply opening is opened to an exterior of the case and is configured to allow ink stored in the ink chamber to pass therethrough; and a light transmissive member disposed in the case and facing the ink supply opening, wherein the light transmissive member is configured to allow light entering via the ink supply opening to pass through the light transmissive member, wherein the light transmissive member comprises a particular reflective surface, which has a first reflectance for the light entering via the ink supply opening and passing through the light transmissive member when the particular reflective surface contacts the ink stored in the ink chamber, and which has a second reflectance for the light entering via the ink supply opening and passing through the light transmissive member when the particular reflective surface does not contact the ink stored in the ink chamber, wherein the first reflectance is different from the second reflectance.