Abstract: A technique of achieving optimal noise suppression with respect to a video signal whose noise amount differs according to brightness is disclosed, and according to the technique, a low-luminance detecting section 18 detects a video signal of a relatively low luminance, a suppression amount setting section 19 generates a noise suppression amount which becomes larger as the luminance of the video signal becomes lower, and a noise suppressing circuit 17 suppresses noise with the noise suppression amount generated by the suppression amount setting section with respect to the video signal of a relatively low luminance detected by the low-luminance detecting section.
Abstract: A wireless communication network system includes a communication controller, and a plurality of terminal devices which can communicate with the communication controller by wireless. The communication controller includes a first section for detecting absence of a received signal from any of the terminal devices, and a second section responsive to an output signal of the first section for periodically generating a nonbusy signal, which can be discriminated from another signal transmitted from the communication controller, in the absence of the received signal. Each of the terminal devices includes a third section for detecting the nonbusy signal, and a fourth section responsive to an output signal of the third section for permitting transmission from the terminal device after the nonbusy signal is received by the third section.
July 1, 1994
Date of Patent:
June 17, 1997
Victor Compay of Japan, Ltd., NTT Data Communications Systems Corporation