Patent GB-870468-A (GB)
Title: Improvements in or relating to books, periodicals and other articles of printing on paper sheets or the like
IPC: B42D15/00
Filed: 1958-05-13
Abstract: 870,468. Viewing devices. VAN DEN BERGH, G. May 13, 1958 [Nov. 4, 1957], No. 15272/58. Class 97(1) [Also in Groups XV and XVI] To economise in paper in printed matter such as books, periodicals or single sheets, the lines are printed closer together than is usual, with the lines of two or more text portions in one or more colours interjacent, or the lines of one text portion may be superimposed on another text portion, and screening or masking means is provided to make legible the group of lines of one of these text portions whilst covering or suppressing the group of lines of the or every other text portion. In one form (Figs. 1 and 2, not shown), the lines of the pages of a book are all printed in capital letters with a line space of only half the height of the type, and the odd numbered lines form a consecutive text which is continued by then reading the even numbered lines. To enable either the odd or even numbered lines to be read, a loose reading-screen is provided consisting of a flexible sheet of transparent material on which opaque cross-bands have been printed or applied, and an elastic band is incorporated for attaching the screen over a printed page. In another form (Figs. 3 and 4, not shown), which can be used for teaching languages, the first line is in French, the second in Spanish, the third in German, and so on, and the associated reading-screen is entirely opaque but provided with slotted windows through which the selected text is read. The even numbered lines in another embodiment, can be printed inverted, so that the continuation of the text can only be read when the page has been inverted : a whole book may be printed in this manner such that the book is read fully by reading all the pages in one direction, and the book is then reversed and read in the opposite direction. As shown in Fig. 6, the text of the pages 1 of a loose-leaf book is printed in two columns very close to each other and to the edges of the pages, and the screen or mask 6 is opaque with transparent windows 11 arranged along the height thereof. The stiff binder 19 has a number of pins or rings 20 engaging slots or holes in the pages 1, and the screen 6 has openended slots 22 which are notched at 23 : the screen is accurately located for reading the appropriate text by engaging one set of notches 23 with the rings 20. In the form shown in Fig. 8, the reading screen 16 extends across two pages of the open book 17, has a central fold 16a, is opaque with two sets of transparent windows 11, and is removably attached to the book cover by strips, clamps &c. 18. The print may be so small that the reading-screen must also provide magnifying means. Such a screen, shown on a greatly enlarged scale in Fig. 7, consists of a plastic transparent sheet 12 which has formed on its upper surface a series of semi-cylindrical projections 13 extending across the sheet, and white opaque coatings 14 on its lower surface are spaced apart to allow the print to be seen through selected projections 13. In this case, only the height of the print is magnified. This screen may be fixed, and the printed sheet moved step-by-step downwardly beneath the screen. In modifications, the texts may be printed in different colours, in which case the screen has transparent coloured windows to suit. Screens having windows in colours complementary to the coloured print of texts may be used as filter means which allow a certain text to be read and mask the other texts. One text in one colour may be printed over another text in a different colour, and a reading-screen and a screen having colour filter windows are used to enable the texts to be read.