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.
A TELEVISION FILM SCANNER
19
film perforations can be maintained in good condition over a longer period of time.
The film transmitter under discussion employs no moving optical elements and operates on the following principle : The motion picture film has to pass a gate at a speed of 24 frames per second while one frame has to be scanned electrically within Veo of a second. This means that within Via of a second two complete motion picture frames have to be scanned electrically five times.
In Fig. 1, frame A, which has just emerged from the top of the gate, is moving downward at a constant rate of 24 frames per second. At the same time a fictional scanning-light spot starts to scan the same
FIG. 1. Illustrating passage of film in gate.
frame from the bottom upward. After Veo of a second the scanning spot describing horizontal lines will have covered a height of 3/6 °f a frame, which, plus a downward 2/5 motion of the frame, equals the picture height. Position B indicates how far frame A has moved in the gate within Veo of a second while it was scanned once from bottom to top. The scanning-beam returns now to the base-line of that frame, and while the frame continues from position B toward position C, the scanning spot, again in Veo of a second, covers that frame. Now the frame continues to move from C to D, which trip again lasts Veo of a second, and the scanning spot quickly returns to the base-line of C and moves upward, completing the third frame. By that time a new frame, E, appears in the gate. The scanning