| 摘要 |
PURPOSE:To attain the recording prevention and index detection, by forming at least a part of a magnetic disc cassette with a transparent body of light, transmitting and interrupting the light, and detecting rays at the side a recording and reproducing device. CONSTITUTION:At least a part of the magnetic disc cassette is formed with the transparent body of light. For example, a transparent part 1a is provided at the upper and lower part of the cassette around a recording prevention detection section to form the recording prevention mode through the presence/absence of the output of photocouplers 10, 11. A sheet 9 is sticked to interrupt the light. A transparent section is provided at the uper and lower part of the cassette at an index hole 8 and the index is detected with the photocouplers 10, 11 with a label 12 to be sticked. In sticking the label and sheet selectively at the transparent part of the cassette, the recording inhibition mode is attained or the index is detected. Thus, complicated openings of the cassette is made unnecessary and the change of the detection means at the device side is made easy. |
