| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily discriminate the type of a recording medium which is carried by simple constitution by detecting transmitted light quantity obtained by projecting light emitted from a light emission part toward the recording medium through a shielding member having a passing groove and arithmetically operating it. SOLUTION: A shielding plate 202 having a slit hole is arranged between a light source 201 and the recording medium 200. The light emitted from the light source 201 arrives at the medium 200 except the part thereof shielded by the plate 202. Then, the light is attenuated according to the density, the thickness and the color of the medium 200. A light receiving sensor 203 is held by the holding part 204 of a scanning carriage so as to scan the medium 200 before a printing action is started. Based on data detected by the sensor 203, the characteristic data of light quantity is arithmetically operated by a CPU 100. Then, the arithmetically operated characteristic data of the light quantity is compared with the characteristic data of the light quantity stored in a memory 207 and the type of the medium 200 being carried is discriminated.</p> |
