| 摘要 |
PROBLEM TO BE SOLVED: To provide an ink cartridge in which detection accuracy can be enhanced when the residual quantity of ink is detected using an optical means. SOLUTION: When ink 71 exists up to the position of an inclining part 51a (Fig. 4a), light (optical path X) emitted from an infrared light emitting element 19a passes through the inclining part 51a and arrives at a reflecting member 53 while passing through the ink 71. Since the inclining part 51a is inclining by about 20 deg. against the reflecting member 53, the light arriving at the reflecting member 53 has an incident angle different from the incident angle to the inclining part 51a. Since the majority of light arriving at the reflecting member 53 is reflected by the reflecting member 53 in a direction different from the incident direction, the light being reflected to an infrared light receiving element 19b can be suppressed. When the ink 71 does not exist up to the position of the inclining part 51a (Fig. 4 (a)), light is reflected on the inner interface of the inclining part 51a and the reflected light thereof (optical path Y) arrives at the infrared light receiving element 19b. Consequently, residual quantity of ink can be detected based on the intensity of reflected light. |
