We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
Bi -Parks and Tri-Packs 165
E. A. Lage33 patented the superposition of three films, each sensitized for different spectrum colors, and brought into optical contact by expressing the intervening air by the pressure of rollers. This is exactly on the same lines as the Smith plate, see above.
S. Schapovaloff34 proposed to coat one layer of emulsion on celluloidcoated glass, then another layer of celluloid and a second emulsion, finally a third celluloid layer and emulsion. The emulsions might be colorsensitized and thin filter coatings interposed. The celluloid layers would easily strip from the under gelatin layers. This also is like Smith's process. The same inventor35 patented a method of printing from the three negatives, preferably on films and of which at least two were joined together at one edge on to a transparent support coated on both sides. The registered negatives being connected by their edges, bookwise, the bifoliate film was twice the length and breadth of the picture and was coated on one side with ordinary emulsion and carried on the other a non-actinic screen, the film being folded centrally so as to provide in superposition an emulsion layer, support, screen, emulsion, screen, support and emulsion. The negative films were assembled with the bifoliate film by laying on each side and enclosing the third in the fold. The first image was printed on the film carrying only one emulsion. Then this was lifted aside with its negative and covered with black paper. The other two images were then printed in succession, or simultaneously from opposite sides. In this way three positive images already registered were produced on the bifoliate film. In a modification the bifoliate film comprised two emulsions on opposite sides of celluloid to which was connected a white paper carrying the third emulsion, or this might be on a separate support.
C. S. Forbes36 proposed to use a bi-pack roll film, the opaque backing bearing a sensitive coating in contact with an emulsion on celluloid. The front film was to be sensitive to green and the rear to red and ultraviolet. L. von Tolnay and L. von Kovodsznay37 patented a tri-pack with interposed filters, the members being pressed into contact under a vacuum. F. Rolan38 patented a bi-pack with yellow-sensitive front film and blue-sensitive rear film. The two negatives thus obtained were combined to give the third color image.
1. "La Triplice Photographique," Paris, 1897, 214. Cf. F.P. 216,465; Bclg.P. 110,803; U.S.P. 544,666.
2. Ibid. 223; Jahrbuch, 1897, 11, 342; Amat. Phot. 1896. 15; 1903, 86; Monde Phot. 1895; Phot. Archiv. 1896; Rev. Suisse Phot. 1895, 342; Wien. Mitt. Blatt. 1896, 163; Jahrbuch, 1896, 10, 422; "Handbook to Photography in Colours" London, 1900, 10.
3. D.R.P. 146,149; 146,150. 1902; 146,151, 1903; Silbermann. 2, 357, 407; F.P. 330,962; addit. 1,689; 1,702; Belg.P. 169,534; Can.P. 88,484; E.P. 7,924. 1903; U.S.P. 730.454; Phot. Ind. 1903, 497; Phot. Mitt. 1903, 39, 220; Phot. Woch. 1903, 29, 289; Amat. Phot. 1903, 86; Chem. Ztg. 1905, 29. 131; Jahrbuch. 1904. 18, 207; Phot. Chron. 1904, 11, 109; J. S. C. I. 1903, 22, 820; Der Phot. 1924. 34, 13. In his second German patent Gurtner specifically claims the binding together the edges of the plates. Special two-ftlm plates for this process wen introduced by