| 摘要 |
<p>PURPOSE:To eliminate the dispersion of measurement for each device by containing a tape in a cassette container whose both ends have light passing holes and whose inside is dark in measuring the light shield efficiency of a cassette tape, making a diffused light incident therein to detect the transmitted light from the tape and cooling the light source by means of a fan in this case. CONSTITUTION:A tape cassette container 15 whose inside is colored in dark and whose both ends have the light transmission holes 7L, 7R is provided to the bottom of one case 100 and a tape cassette 1 to be measured is contained therein. Moreover, a light source container 21 having a diffusion glass 31 at its lower face and having a light source 16 on the ceiling is provided onto the container 15, the diffused light therefrom is transmitted through the tape 1 via the holes 7L, 7R, the light is received by the photodetectors 17L, 17R, converted into an electric signal and inputted to a light shield effect detection means 18. Through the constitution above, plural external vents 36a-36c are made to the case 100, a fan 35 is employed to exhaust the internal air from an exhaust outlet 37 to cool the light source 16 and a reflecting plate 22 surrounding the light source.</p> |
