Matsushita Electric Industrial Co., Ltd.

Koichiro Nagata

Masazumi Yamada

Yutaka Nio

Hidekazu Suzuki

Masashi Imai

Takaaki Hoshi

Toru Watamoto

On a display () end, maker codes and device codes are read from all STBs () connected to the display () to create a connected-device table. When a user presses a button on a remote controller, the display receives a remote control code outputted from the remote controller, searches the connected-device table for a maker code and a device code that match the maker code and the device code included in the remote control code, controls a selector () so that a reception interface that is connected to an STB whose maker code and device code match those included in the remote control code is connected to a display section (), thereby to display AV data transmitted from the STB on the display section ().

Audio visual system

In a display device used together with a playback apparatus such as an optical disk, a control is provided responding to a playback signal from an playback apparatus in order to prevent burn-out of CRT phosphor or deterioration of phosphor. A first controller controls the playback apparatus, and a second controller controls the display device, and those two controllers communicate with each other, thereby recognizing an operation status and a display status. Thus those two controllers control circuits and apparatus including a video control circuit which controls a contrast, whereby optimizing a display on a screen, and control status of an audio output, a power supply controller, and a playback apparatus controller.

Playback control apparatus for controlling a playback unit and a receiver unit

An image display device having (a) a DVD or a CD, (b) a television receiver, (c) a display for displaying an image from the DVD and the television receiver, (d) a screen burn-in preventer, and (e) a deterioration protector for protecting the display device from deterioration. The screen burn-in preventer discontinues reproduction from the DVD when an image reproduced of the DVD becomes stationary, and the stationary state continues for the predetermined time period. The deterioration protector discontinues reproduction from the DVD at a second predetermined time after the television receiver is turned on while an image reproduced from the DVD is displayed by the display.

Image display device

Class D amplifiers are difficult to incorporate into audio amplifier systems because of the interference created by the amplifier and/or the surrounding circuits. The modulation frequencies f1 and f2 of two class D amplifiers in an audio amplifier system are adjusted so that the frequency f1-f2 of interference between the modulation frequencies is outside the reproducible frequency band B1 of speakers converting the class D amplifier output to audible sound. As a result, interference that may result from simultaneous use of two class D amplifiers for similar purposes is inaudible and not perceived as noise.

Audio amplifier system using a class D amplifier

A protective circuit and a signal processor for a three-CRT projection TV for preventing CRT burnout, deterioration of luminous characteristics, and damage to lenses by heat. Each CRT beam current detection circuit detects the beam current of each CRT. A state of the video image is predicted based on the detected beam current values and their duration. A microcomputer determines a control voltage for controlling the contrast based on the state of the video image, detected values, and their duration. The contrast is thus controlled by a control signal output to a video control circuit which controls the beam current.

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Ibaraki, Japan

Koichiro Nagata