Aperture Cards

Aperture Cards are a combination of old-style IBM punch cards and microfilm. A cut-out aperture area on the card contains a 35mm microfilm image of a document, typically a blueprint or other engineering drawing. Information about the drawing (such as the title, version, page, etc) is punched into the card (in what is called Hollerith code) and printed along the top. An aperture card scanner reads the punch data and scans the microfilm window. The result is a digital image similar to what is produced from a paper scanner. The punched textual information is often used to automatically index the scanned image, allowing unattended batch input of thousands of cards at a time. As strange as this media may seem, it is actually a compact way to store hundreds of thousands of engineering drawings that would otherwise take up warehouses full of paper blueprints. Of course, as efficient as aperture cards may be, we believe a purely digital form is even better.

Paper Documents Microfilm Microfiche Aperture cards

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