| 摘要 |
<p>PURPOSE:To detect ink securely with a low cost and a low running cost. CONSTITUTION:An apparatus comprises a light emitting part 110, an ink flow path 103 consisting of an ink flow path wall 101 which permits light to pass from the light emitting part 110 through it and an ink flow path wall 102 with a reflecting surface 102a, and a light receiving part 111 for receiving light which has passed through the ink flow path 103. Difference in light refractive indexes due to existence of ink in the ink flow path 103 is detected.</p> |
