| 摘要 |
PURPOSE:To eliminate the need for adjustment in terms of aging deterioration and that for every fluorescent lamp, by providing strips of shielding members between the fluorescent lamp and an original surface lenghtwise along the lamp. CONSTITUTION:Eight shielding members 6a-6d symmetric on surface H perpendicular to axial line X and penetrating axial center C of fluorescent lamp 1 are arranged. The arrangement pitch is smaller at the center part and larger at both ends. Center members 6a are arranged in parallel to original face 4 and members 6d at both ends are arranged spreading out and slanting so that the distances from members 6a increase toward face 4. Intermediate members 6b and 6c are slanted more than members 6a and less than 6d respectively. Then, angles of members 6b-6d are set with thetad>thetac>thetab and their values are adequately set; and the width of an opening between adjacent members is set with W0<W1<W2<W3 and light beam penetrating them increses the intensity of illumination on face 4 at both the ends, so that the shade of an image on photo detection surface 8a of photo detecting element 8 at the circumference of lens 7 can be corrected. Thus, no light at both the ends is used in this mechanism to eliminate the need for adjustment in terms of dispersion, etc., in lamp light. |
