Abstract: Use of an especially small-sized and valuable display device (b 31) is limited to persons knowing a password, not by any requirement that a password (33) always be entered when the display device (31) is switched on, but rather detecting, the detachment of the display device (31) from the equipment (35-39) controlling it and measuring its time of being detached, for limiting the use of the display device (31) on the basis of a certain predetermined and adjustable time limit which, when exceeded, requires the password be entered.

Abstract: The invention relates to a method for synthesizing a virtual sound source in a system (40) which comprises at least a right and a left channel for transmitting a stereo signal and in which the channels are connected to a filter block (42) for expanding the sound image. In the method, the amplifications of the separated monophonic and stereophonic signal components are optimized according to the stereophony of the signal coming to the system. The method according to the invention can also be applied to producing early room reflections by means of a separate filter block (71). The invention also relates to a device for synthesizing a virtual sound source, which device comprises at least a first and a second channel for transmitting the signal, at least one amplifier and filter and means for estimating the stereophony of the signal, for determining the amplification coefficient of the filtered signal and for controlling the amplifier according to the calculated amplification coefficient.

Abstract: A method and a system for loudness calibration of a multichannel sound systems, wherein the test signal is psychoacoustically shaped. The psychoacoustically shaped test signal is preferably a pseudorandom test signal suitable for both automatic and subjective loudness calibration. Further, the psychoacoustically shaped test signal preferably has essentially constant specific loudness on the frequency range essential for aural perception.

Abstract: A method and a device for power management regarding an integrated display unit including a video display and at least one peripheral device, wherein the video display uses horizontal and vertical sync signals for the synchronization of the display images, and the peripheral device uses a peripheral signal to carry out its function. The peripheral device can be an audio unit using audio signals to produce sound. The peripheral device can be a USB connector using a +5 V voltage to indicate a connection being made to the integrated display unit. In the integrated display unit, a single power supply is used to provide electrical power to the video display and the peripheral device. In order to reduce the power consumption by the integrated display unit, a number of power consumption states, based on the presence of the video sync signals and the peripheral signals, are implemented. The presence of the video sync signals can be detected by a micro-controller in the integrated display unit.

Abstract: Control of display power management by a host computer connected by a standard cable to a display monitor can be avoided by simply detecting user inactivity within a monitor or signaling such to the monitor with any one of the DPMS signals to the monitor, such as the video signal, i.e., the video intelligence signal occurring between horizontal synchronization pulses. In the absence of the video signal, the monitor commences timing of several display power management states without further reference to the DPMS signaling signals, except to monitor whether the video signal returns to normal. In the absence of a return to normal on the video signal, the display monitor transitions from a normal state to a standby state, thence to a suspend state, and finally to an off state. If user activity is again detected, a transition from any of these display power management states to normal is made.

Abstract: The invention relates to a method and a device for reducing an electric field produced by display devices equipped with cathode ray tubes, in their surroundings. According to the invention, a part of a spectrum (ff), caused by a picture content, the level of which is separately adjusted, is discriminated from an interference voltage frequency spectrum (fs), produced by the display terminal and caused by deflection signals (fv, fh). Spurious pulses, significant for the generation of the electric field, are connected to a compensation circuit, wherein they are summed and supplied to a common emitter. The directions of the pulses are determined so that the electric field produced by the emitter reverses the field produced by the display device.

Abstract: The invention relates to a method for adjusting the colour temperature in a liquid crystal display with background lighting. According to the invention, the liquid crystal display is lit by two or more background light lamps with different colour temperatures (LAMP 1, 2, 3, 4, 5), the colour temperature range of the background light is extended and better opportunities for adjusting the colour temperature by changing the pass rate of the light are provided. In a more advanced solution, background light lamps with different colour temperatures (LAMP 1, 2, 3, 4, 5) are switched on (S1) separately for setting the colour temperature of the display, and furthermore, the brightness of the background light lamps (LAMP 1, 2, 3, 4, 5) with different colour temperatures can be adjusted separately for setting the colour temperature.

Abstract: The invention relates to a method and apparatus for correcting image errors caused by residual magnetism in monitors and other such display devices based on picture tubes. The method according to the invention is based on the removal of residual magnetism by means of an alternating damped magnetic field. In the method, the internal and external structures in the neck part (11) of a picture tube (10) are subjected to an alternating damped magnetic field produced by means of a coil (45).