Electric Functional Unit and Cathode Ray Tube Visual Display Unit

1. Field of the Invention

The invention relates generally to video systems and more specifically; to an electric functional unit and a cathode-ray tube visual display unit according

Cathode-ray tube visual display units convert energy into heat which is unused. In particular, cathode-ray tube visual display units with a color screen have, for example, a power loss of about 100 watts. In when used with an electric functional unit as a control device, such as for example a personal computer, the cathode-ray tube visual display units known here as monitors usually run in continuous operation, although the actual time of use makes up only a fraction of the operating time.

There are admittedly known visual display units of the Nixdorf company, for example BA 80, which switch into an energy-saving state when a monitor is out of action for lengthy periods. Here, however, the monitor is firmly connected to the control device, so that it is possible by virtue of the precise matching of the devices to each other for example for the synchronizing signals of the monitor to' be switched off without any problem.

In the case of a so-called "open arrangement", that is to say in an arrangement with a control device and a cathode-ray tube visual display unit as individual devices, such a control cannot be carried out, because otherwise monitors not belonging to the arrangement would produce an unsynchronized flickering image. However, monitors should be able to operate on every system envisaged for them without adversely affecting the basic function of said system. Similarly, the control device should be able to operate each monitor in its basic function.

The document EP-A-0 456 923 discloses a screen display system with a computer unit in the form of a personal computer and a cathode-ray tube visual display unit. The screen display system has in addition to an interface for supplying the cathode-ray tube visual display unit for its basic function with corresponding signals an additional serial interface for coded signals between the computer unit and the cathode-ray tube visual display unit. The system is constructed in such a way that in the cathode-ray tube visual display unit there is provided a read-only memory for device-specific parameters, such as for example resolution and geometry of the screen or activation times. When switching on the system, these parameters are read out from the computer unit and the computer unit sets itself to the connected type of cathode-ray tube visual display unit. There is no mention of the problem of putting the display unit in a predeterminable energy-saving state by the computer unit via the interface which supplies the cathode-ray tube visual display unit with appropriate signals for its space function.

U.S. Pat. No. 5,059,961 discloses a computer system in which a signal is generated if no further data are entered into the computer system. This situation means that no one is working on the computer system. The signal is-relayed to a time monitoring unit and starts the latter. After a predetermined period of, time, the time monitoring device generates a further signal, by which the horizontal and vertical synchronizing signal for a cathode-ray tube visual display unit is blocked. All other electrical functions remain unchanged. By the blocking of the synchronizing signals, the cathode-ray tube visual display unit is blanked. As soon as data are entered into the computer system again, the synchronizing signals are released and a screen display reappears. The specified measures are intended to avoid burning of the inner surface of the picture tube caused by the presence of a static image during phases in which no one is working on the computer system. There is no mention of the problem of putting the cathode-ray tube visual display unit into a predeterminable energy-saving state by sending out a corresponding message in coded form to the cathode-ray tube visual display unit via the interface which supplies the cathode-ray tube visual display unit with appropriate signals for its basic function.

Patent Abstracts of Japan, JP-A-1 269 979 discloses a device arrangement having-a cathode-ray tube visual display unit with a queuing condition function and a control device supplying the cathode-ray tube visual display unit with appropriate signals for its basic mode of operation via line connections of a standard interface. The device arrangement comprises, in a keyboard signal line, a signal evaulation circuit which switches off the power supply of the cathode-ray tube, visual display unit by means of a power supply cut-out switch if the signals on the keyboard signal line do not alter for a predetermined period of time. Consequently, the cathode-ray tube visual display unit does admittedly assume a state similar to an energy-saving state. However, owing to increased switching on/off cycles due to the respective total shut-down of the power supply, the modules of the cathode-ray tube visual display unit are prematurely worn, as a result of which the lifetime of the device is shortened. Thus, this is not an energy-saving control which preserves components. In addition if the tube heating is maintained, there is the risk of "cathode poisoning".

It is known from German Utility Model G 90 12 582.7 U and the document GB-A-2 007 471 for to control a queuing condition function of the cathoderay tube visual display unit by using the line connections, in particular the video signal line, of a standard interface for operating the cathode-ray tube visual display unit. In this case, however, only a blanking of the cathode-ray tube is possible, as a result of which burning is indeed prevented, but there is no preservation of the components by power reduction of as many components as possible or shut-down owing to the otherwise full operating state of the cathode-ray tube visual display unit. There is no mention of the problem of putting the cathode-ray tube visual display unit into a predetermined energy-saving state by sending out a coded message to the cathode-ray tube visual display unit via the interface which supplies the cathode-ray tube visual display unit with appropriate signals for its basic function.

It is known from the document DE-C-3 8 620 for the blanking of a cathode-ray tube visual display unit to provide a proximity switch which permits controlling of a queuing condition function independently of the actual controlling of the cathode-ray tube visual display unit. Owing to the otherwise full operating state of the cathode-ray tube visual display unit, however, here too there is again no preservation of the components by power reduction or shut-down.

The object of the invention is to provide an electric functional unit and a cathode-ray tube visual display unit having the possibility of controlling on the part of the control device at least a first predetermined energy-saving state of the cathode-ray tube visual display unit preserving as many components as possible by sending out an appropriate message to the cathode-ray tube visual display unit by power reduction or shut-down, without thereby restricting the use of the individual devices to an arrangement in which both the control device can control the energy-saving state of the cathode-ray tube visual display unit and the cathode-ray tube visual display unit is controllable with respect to an energy-saving state.

This object is achieved according to the invention by an electric functional unit (EFU) and cathode-ray tube visual display unit (CRT VDU) apparatus, having an electric functional unit (EFU) having means for generating a coded message, the coded message having at least two types of control information including a predetermined energy-saving state, a cathode-ray tube visual display unit (CRT VDU) having means for evaluating the coded message received from the EFU, a standard interface having connection lines for supplying the CRT VDU with basic function signals from the EFU, the EFU and the CRT VDU each having respective connection points to connect the connection lines of the standard interface, and matched means for transmitting the coded message including the predetermined energy-saving state from the EFU to the CRT VDU to put the CRT VDU into the energy-saving state.

By putting the cathode-ray tube visual display unit into an energy-saving state by means of a coded message on the part of the electric functional unit to the cathode-ray tube visual display unit, there is the possibility of switching off after a first period of time only those parts of the cathode-ray tube visual display unit which are not required for a quick restart. Consequently, energy-saving operation which preserves components is possible. After a second period of time, the cathode-ray tube visual display unit can then be switched off completely, whereby a 100% energy saving is achieved.

Since transmission of a message for controlling an energy-saving state of the cathode-ray tube visual display unit which is independent of the function of the standard interface is possible, the individual devices are not respectively dependent on a correspondingly conversely designed other device. The basic functions of the individual devices are provided for irrespective of their mutual design with respect to the possibility of controlling or accomplishing an energy-saving state. If the devices are not correspondingly conversely designed, it is simply that either the cathode-ray tube visual display unit cannot receive or evaluate the message for controlling the energy-saving state or that the control device cannot transmit such a message in the first place. Although the advantage of the energy-saving state cannot be used in these cases, the individual devices as such remain universally usable.

In particular, it is advantageous if the control device, has a device for switching off the function of the transmission of a message controlling the energy-saving state of the cathode-ray tube visual display unit, because then cathode-ray tube visual display units can be operated reliably, free from any disruptions, without the energy-saving state, or without a corresponding configuration for controlling the energy-saving state.

An exemplary embodiment of the invention is explained in more detail below with reference to a drawing.

The figure shows a control device PC and a monitor of the present invention interconnected via a standard interface SS.

The monitor M is supplied with appropriate signals for its basic function via the standard interface SS. The standard interface SS shown has three line connections, of which two are responsible for the transmission of synchronizing signals Hsync, Vsync in the X direction and Y direction, respectively, of the monitor M and the third is responsible for the transmission of a video signal VS. However, any -other desired standard interfaces are conceivable. For example, those for the operation of monitors with a color screen and analog input. In this case, the standard interface would have, for example, three line connections for a video signal of a predetermined color each. In the case of those with a digital input, the number of video signal lines would, for example, correspond to the number of possible color/brightness stages of the image to be generated. For controlling the energy-saving state-of the monitor M a message in coded form is transmitted on the line connections of the standard interface SS. Apart from the line connections of the standard interface SS, no further line connections are needed.

For transmitting the message controlling an energy-saving state of the monitor M, the control device PC has a video coder VC, which codes the message and integrates it into the video signal. For example, a video signal .gtoreq.0 is transmitted during the horizontal and/or vertical flyback phase of the screen beam. In this case, the message generating function should be optionally selectable by the user, since otherwise flyback lines may become visible under certain circumstances if monitors of a different type are used. However, this effect can be reduced by special selection of the level and of the color.

The monitor M has a so-called "power stand-bye" decoder PSB-DC, which filters out from the transmitted signals a message PSB decisive for controlling the energy-saving state.

The PSB decoder PSB-DC can also be made to activate a "power stand-by state" by complete or partial switching off of the sync signals. It is advantageous at least in this case if the control unit PC has a device for switching off the function controlling -the PSB decoder which can be operated freely selectively, for example by a user of the control device PC. This could take place, for example, by so-called setup menu switches.

Although other modifications and changes may be suggested by those skilled in the art, it is the intention of the inventor to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of his contribution to the art.