| 摘要 |
<p>PURPOSE:To reduce differences in quantity of light between LED array chips and enhance the uniformity of the quantity of light emitted from an LED array head, by ranking the LED array chips on the basis of the medium of light quantity distribution in each of the chips, and constructing the LED head by assembling together the chips which have equal medians. CONSTITUTION:Let the light quantity distribution characteristics of two LED array chips be respectively (a) and (b), the median of the distribution (a) be a', the average of the distribution (a) be a, the median of the distribution (b) be b' and the average of the distribution (b) be b. Then, a light quantity distribution characteristic obtained by assembling two chips (a), (b) with the medians a', b' of the distribution equal to each other is as shown in (c), whereas a light quantity distribution characteristic obtained by assembling the chips (a), (b) with the averages a, b equal to each other is as shown in (d). The range of the light quantity distribution in the case of (d) is wider than that in the case of (c), so that the chips corresponding to (d) include a larger number of LED elements showing a conspicuous light quantity difference.</p> |
