Abstract: A communication system includes a wire network, a first terminal device, and a second terminal device. A first master device connected to the wire network transmits and receives data to and from the first terminal device by wireless at a first data rate. For example, light is used by the wireless data transmission between the first master device and the first terminal device. A second master device connected to the wire network transmits and receives data to and from the second terminal device by wireless at a second data rate lower than the first data rate. For example, radio is used by the wireless data transmission between the second master device and the second terminal device. A server connected to the wire network manages addresses of the first and second master devices.

Abstract: In a video signal recording apparatus, a first video signal is compressed into a second video signal in response to a controllable quantization factor which determines a degree of the compression. The quantization factor is controlled to maintain a data rate of the second video signal at substantially a constant rate. A detection is made as to a magnitude of the quantization factor. A decision is made as to whether or not the detected magnitude is greater than a predetermined reference magnitude. The second video signal is recorded on a recording medium when the detected magnitude is greater than the predetermined reference magnitude.

Abstract: In a video signal recording apparatus, a first video signal is compressed into a second video signal in response to a controllable quantization factor which determines a degree of the compression. The quantization factor is controlled to maintain a data rate of the second video signal at substantially a constant rate. A detection is made as to a magnitude of the quantization factor. A decision is made as to whether or not the detected magnitude is greater than a predetermined reference magnitude. The second video signal is recorded on a recording medium when the detected magnitude is greater than the predetermined reference magnitude.

Abstract: A sample hold circuit has a first sample hold circuit and a second sample hold circuit, which are of the same in circuit configuration, each having a clamping circuit at an input stage of the sample hold circuit and a sample-holding circuit at the next stage, and the first sample hold circuit and the second sample hold circuit receiving commonly at least a clamping reference voltage, a clamping control signal for the clamping circuit and a sampling control signal for the sample-holding circuit. An output of a CCD image sensor is inputted to only one of the first sample hold circuit and the second sample hold circuit, whereby the output signals from the first sample hold circuit and the second sample hold circuit are outputted in a differential mode. It is possible to reduce low frequency 1/f noise and reset pulse noise in the image signal produced by the CCD image sensor by inputting the output signals from the first and second sample hold circuits to a differential circuit.