摘要 |
<p>A prism is provided for deflecting light through the tape information holes in the tape of a data cartridge. The prism includes a substantially hollow main prism body. The inside surface of the angled prism surface is formed in steps, so that light passing into the angled portion passes in the normal direction through a step, is reflected off of the angled surface, and then passes in the normal direction through the adjacent side of the step, or the adjacent side of the next step. In this fashion, minimal plastic material is required for the prism, while light reflection is restricted to only a single surface. An alternative embodiment provides steps on the internal surface of a mirror, instead of a prism.</p> |