JPS57531A - Two dimensional luminance measuring device - Google Patents

Abstract

PURPOSE:To measure two dimensional luminance in a wider dynamic range with easy removal of noise and in a short measurement time by detecting single photon input by using an image dissector tube and integrating the same over an arbitrary time. CONSTITUTION:The image of a standard light source is projected to an image dissector 3, and the X coordinate deflection position signal (a) and Y coordinate deflection position signal (b) corresponding to the position of the image of a standard object 1 to be measured from a deflection signal generator 8 are transmitted to deflection driving circuits 88 and 89. Thereafter, the input gate circuit 41 of a pulse counter 4 transmits square wave pulses (c) to a control terminal and has them counted. The count number thereof is stored in a memory 52. Following to this, a desired object 1 to be measured is installed, and the deflection position signal corresponding to desired measurement points are successively transmitted. The pulses are counted only for the time width of the pulses (c). These are divided by the output signal of the memory 52 as a divisor in the divider 53 of an arithmetic circuit 5, and the results are transmitted to the 1st input terminal 61 of a multiplexer 6 for data. After the signal processing of all the points is completed, the results are displayed in a display device 7.