[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

CFF (Critical Flicker Frequency) determinations were made at various retinal positions by using a fixation point to which the line of vision is fixed in the first test and by employing a moving target which led the line of vision in the second test.
It is inferred from the results of the tests that CFF in the periphery is higher than that in the fovea when the target size is larger than 2°, and that the variation of OFF according to the locality on the retina in the case where the target size is very small (less than 1/8°) depends basically upon the density distribution of cones and rods on the retina.
It is also pointed out that CFF is higher during eye movement than when the line of vision is fixed, especially when the target size is large and in the periphery of the retina.

View full abstract

In order to find out clues for improving the beam discharge lag in widely used photoconductive pickup tubes with blocking contacts, the author looked into the following aspects in the scanning electron beam performance as the factors affecting the lag : (1) Energy distribution broadening due to relaxation in the scanning beam. (2) Beam convergence angle on the target. (3) Angle of incidence of the beam on the target. (4) Local distribution of contact potential difference between target and cathode. (5) Second exponential region of the beam acceptance curves.
The author has worked out a computational procedure to follow the surface potential variation on the target and investigated the correlations among the beam performance, the resultant beam acceptance curves and the beam discharge lag.
It is concluded that the relaxation has the most predominant effect and that the other factors add only minor influence on the decay lag characteristics due to beam discharge.

View full abstract

Relations between distortion caused by multipath transmission and the essential parameters are analyzed for both monophonic and stereophonic FM sound broadcasting.
The parameters involved are DU ratio, delay time of the reflected wave in comparison with the direct wave, phase difference of these two carrier waves, modulation frequency and percentage of modulation.
Fast Fourier Transform processing technique is applied in the computer programme using which the complicated spectrum computation is carried out easily to allow a thorough analysis of multipath transmission phenomenon.
As a result, the complex nature of multipath distortion became clearly understandable. In addition, some considerations necessary for the better reception of FM sound broadcasting under the environment of multipath transmission are derived from the results of analysis.

View full abstract

[in Japanese]

View full abstract