Method for printing braille characters by lithography
OwnerMartin E. Kurtzmaninventor
Life of this patent
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Abstract
A method for printing braille characters by means of a lithographic printing process in which photosensitive sheet material is exposed to form a dot image of one or more braille characters on the sheet material. The sheet material is then developed and subsequently photographed and a negative made of the developed sheet material. The negative is stripped onto a goldenrod sheet and the stripped negative is exposed on a light-sensitive lithographic plate which is subsequently developed. The dot image developed on the lithographic plate is then offset printed on sheet material stock and the printed sheet stock is passed through a thermography machine to form raised braille characters on the sheet stock.
Claims5
A method for printing braille characters by means of a lithographic printing process, comprising the steps of:
- exposing photosensitive sheet material to form a positive dot image of one or more braille characters on said sheet material;
- developing the exposed photosensitive sheet material;
- photographing said developed photosensitive sheet material and making a negative of said developed sheet material;
- mounting said negative on an opaque sheet and cutting apertures in said sheet to permit light to pass through said negative;
- exposing said mounted negative on a light-sensitive lithographic plate and developing said exposed plate;
- mounting said developed plate on an offset printing press;
- printing the dot image developed on said exposed lithographic plate in ink on sheet material stock by feeding said stock through said offset printing press;
- depositing thermographic material on the image printed on said sheet material stock while the ink forming said image is still wet;
- and
- heating said sheet material stock to melt, fuse and set said thermographic material and form raised braille characters on said sheet material stock.
Dependencies are inferred from the claim text.