Matsushita Electric Industrial Co., Ltd.

Satoshi Hasako

Yuji Igata

Masahiro Maki

Michinori Kishimoto

Shoichi Koga

Junji Kondou

Hiroshi Ikeda

Yukihiro Fukumoto

Kazuhiko Tamesue

Satoshi Shinozaki

A display device comprises an inspection circuit for inspecting a data reception related circuit to generate inspection information, an inspection result image generation circuit for generating image data indicating the inspection information, a display switching circuit for superimposing inspection result image data on test video data, and a display unit for displaying the test video data superimposing the inspection result image data. As a result, it is possible to carry out inspection after assembly of the display device without disassembling the display device. This in turn makes it possible to carry out a test in a simple manner on the data reception related circuit inside the display device without changing noise environment inside the display device.

Display device, receiver, and test apparatus

The power line carrier system provides with a filter in a power branch apparatus removable from an external power line. The filter passes a power line carrier signal in a signal mode for the external power line, and interrupts another power line carrier signal which is in a signal mode different from the mode for the external power line.

Power line carrier system

Impedance values of a common mode choke coil, an impedance element disposed anterior to the common mode choke coil and an impedance element disposed posterior to the common mode choke coil are determined in such a manner that a common mode current flowing into the common mode choke coil does not exceed a value of rated current. Excessive common mode current is prevented from flowing into the common mode choke coil, and saturation and damage of the common mode choke coil is prevented.

Balanced transmission termination device and receiver unit composed thereof

To use high noise transmission lines, such as an electric wire, as the lines to transmit signals, it is imperative to reduce the level of signals. The present invention is provided with a sending signal generating means , which outputs converted data after converting an input signal into a plurality of carrier signals assuming values at such intervals on the axis of frequency that the frequencies may not interfere with each other. If an interfering noise with any one of the plurality of frequencies arises on the transmission line, removal of only a carrier of the noise frequency would leave the communication in a good condition. Furthermore, better results can be hoped for if the respective carrier signals are so arranged as not to interfere with each other or so arranged to intersect orthogonally with each other not only on the axis of frequency but also on the axis of time

Communication systems, sender and receiver

A highly reliable and high-speed data transmission is made by using an FH or MFSK mode as suitably selected according to the usage of channels. When a reception signal is entered into a receiver through a transmission line, (i) a signal processing unit supplies the spectrum intensity values of carrier frequencies, (ii) a channel detection unit controls the phase of a time slot based on the spectrum intensity values, selects the MFSK or FH modulation mode, and supplies reception code data corresponding to detected carrier frequencies, and (iii) a decoder supplies reception information data based on the reception code data. When transmission information data are entered into a transmitter, (i) a coding unit supplies, according to the selected modulation mode, transmission code data based on the transmission information data, (ii) a channel generation unit supplies, based on the transmission code data, carrier frequencies to be used and (iii) a waveform generation unit supplies a transmission signal to a transmission line.

Growing community of inventors

Iizuka, Japan

Satoshi Hasako