| 摘要 |
PURPOSE:To control the illumination of the title apparatus according to the size of each of letters being read, the visual size of each and the age of a reader by detecting the size of each ofletters on the top face of a desk, setting the level of required lighting from the detected size and then lighting up each of the letters at the level of required lighting. CONSTITUTION:A first detecting unit 20 detects the size of each of letters printed on the face of paper. A first arithmetic unit 23 computes the distance between each of the letters and a reader's eyes from the distance between each of the letters and a lighting apparatus, detected by a second detecting unit 21' and also from the distance between the reader's eyes and the lighting apparatus, detected by a third detecting unit 22. A second arithmetic unit 24 computes the visual size of each of the letters from the size of each of the letters, and also from the distance between the reader's eyes and each of the letters. A switch 25 changes the illumination of the lighting apparatus to a required level corresponding to the age of each of readers. There is also a constant correlation between the visual size of each letter and proper illumination corresponding to reader's age, whereby a third arithmetic unit 26 computes proper illumination corresponding to the conditions of the reader's age and each letter, and then the computed illumination control output enables the proper illumination to be obtained. |
