Verifax copier

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The Kodak verifax is a photo copying approach that uses a wet colloidal diffusion transfer technique patented by Yutzy, H.C. and Yackel, E.C. (1947) [1] [2] The light source is projected to the top crossing the negative being reflected -more or less, according to the color- against the original to be copied exposing the negative. Has a base that contains the recipient with the liquid developer and the exposure timer. [3]

Contents

Due to its extreme simplicity, the method was commonplace until the late 1960s, when it was surpassed by the popularity of the xerocopies using plain paper. Copies had some chemical smell and lost contrast over time.

Diffusion transfer

The DT (Diffusion transfer) was widespread in several countries since 1960: [2]

Other products not specifically intended for copying, but employing a similar PMT technology include: Kodak Ektaflex (1981); Polaroid, sepia (1948), id, White Black (1950), id, color (1963)...

Process

See also

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A contact copier, is a device used to copy an image by illuminating a film negative with the image in direct contact with a photosensitive surface. The more common processes are negative, where clear areas in the original produce an opaque or hardened photosensitive surface, but positive processes are available. The light source is usually an actinic bulb internal or external to the device

A thermal copier or thermocopier is a kind of photocopier based on the effect of heat. The original sheet feeds in conjunction with the "thermo-sensitive" paper, generating a copy on its specially treated surface. The black parts on the original sheet, once scanned, make the copier activate the heating elements that produce some chemical reactions on the "thermo-sensitive" copy paper that darkens its surface. After the process, a stable black-and-white image is obtained on the cooled film or paper.

References

  1. Michael R. Peres (20 June 2014). The Focal Encyclopedia ofPhotography. Routledge. pp. 11 –. ISBN   978-1-136-10614-9.
  2. 1 2 cool.conservation us.org
  3. 1 2 Bonnier Corporation (January 1965). "Popular Science". The Popular Science Monthly. Bonnier Corporation: 128–. ISSN   0161-7370. kodak verifax.
  4. Lillian Hoddeson (11 November 2002). True Genius: The Life and Science of JohnBardeen. Joseph Henry Press. pp. 242 –. ISBN   978-0-309-50064-7.