| 摘要 |
PURPOSE:To detect the presence or absence of a disk cassette and the priority of writing with a single photoelectric detector, by providing a writing inhibition pawl to the bottom of a hard case of a disk cassette together with a detector having a light shielding surface opposite to the optical axis of the photoelectric detector with two large and small light transmitting holes. CONSTITUTION:A base 1 contains a detector 68 and a photoelectric detector 67 consisting of a photodiode 65 and a transistor 66. The detector 68 contains a lever 71 which can turn around a support shaft 70 and a pin 72. The lever 71 has a light shielding surface 73 and two large and small light transmitting holes 74 and 75. The pin 72 is fitted to the lower surface side of a hard case 14 and set at level (c) with an unbroken writing inhibition pawl 17. While the pin 72 is set at level (a) and (b) when a disk cassette 4 is not loaded and when the pawl 17 is broken respectively. Thus it is possible to obtain three detection signals with a single detector 67. |
