Abstract: An apparatus and method for handling special windows in a display comprises a window manager in an operating system that is called by application programs to create special windows. The window manager embeds static key signals including encoded special window information, such as the coordinates of a window area to be specially processed, into a video RAM. An existing video interface scans the video RAM and transmits display information, including the key signals, to the display. The present invention further comprises a window decoder in the display, that detects the key signals, extracts the encoded special window information, and controls display circuitry performing the desired special processing. The key signal encoding scheme does not create visually discernible display aberrations that could distract the user or interfere with normal window management.

Abstract: An apparatus and method for handling special windows in a display comprises a window manager in an operating system that is called by application programs to create special windows. The window manager embeds static key signals including encoded special window information, such as the coordinates of a window area to be specially processed, into a video RAM. An existing video interface scans the video RAM and transmits display information, including the key signals, to the display. The present invention further comprises a window decoder in the display, that detects the key signals, extracts the encoded special window information, and controls display circuitry performing the desired special processing. The key signal encoding scheme does not create visually discernible display aberrations that could distract the user or interfere with normal window management.

Abstract: An apparatus and method for handling special windows in a display comprises a window manager in an operating system that is called by application programs to create special windows. The window manager embeds static key signals including encoded special window information, such as the coordinates of a window area to be specially processed, into a video RAM. An existing video interface scans the video RAM and transmits display information, including the key signals, to the display. The present invention further comprises a window decoder in the display, that detects the key signals, extracts the encoded special window information, and controls display circuitry performing the desired special processing. The key signal encoding scheme does not create visually discernible display aberrations that could distract the user or interfere with normal window management.

Abstract: According to one aspect of the invention, a movable cursor control device is provided for controlling a cursor on a display screen of a digital processing system. One exemplary cursor control device comprises a housing, an electromagnetic emitting device coupled to the housing, and an electromagnetic detector coupled to the housing. The electromagnetic detector detects reflections of signals emitted from the electromagnetic emitting device and determines when the housing has been lifted from a surface. In another aspect of the invention, an exemplary method is provided for controlling a cursor on a display screen of a digital processing system. The exemplary method includes holding the cursor relative to an object on the display screen using a cursor control device activated by a user, detecting that the user no longer activates the cursor control device, and detecting that the user has lifted the cursor control device from a surface when the cursor control device is no longer activated by the user.

Abstract: According to one aspect of the invention, a movable cursor control device is provided for controlling a cursor on a display screen of a digital processing system. One exemplary cursor control device comprises a housing, an electromagnetic emitting device coupled to the housing, and an electromagnetic detector coupled to the housing. The electromagnetic detector detects reflections of signals emitted from the electromagnetic emitting device and determines when the housing has been lifted from a surface. In another aspect of the invention, an exemplary method is provided for controlling a cursor on a display screen of a digital processing system. The exemplary method includes holding the cursor relative to an object on the display screen using a cursor control device activated by a user, detecting that the user no longer activates the cursor control device, and detecting that the user has lifted the cursor control device from a surface when the cursor control device is no longer activated by the user.

Abstract: A power-up switch circuit in a peripheral device such as a keyboard is coupled to the main processing portion of a computer via an interface bus. The switch circuit together with bias and detection circuitry in the main processing portion allow non-intrusive use of a data communication line of the interface for controlling the supply of power to the main processing portion, without requiring a dedicated power-on wire between the peripheral device and the processing portion. A repeater circuit between the keyboard and the main processing portion causes a second signal to be sent through an upstream portion of the interface bus in response to receiving a first signal through a downstream portion of the bus, while the main processing portion is in low power mode. The repeater is also configured to not affect the interface bus when the main processing portion is in high power mode.

Abstract: A system for correcting an output device for the effects reflected ambient illumination comprises an output device, a calibration memory, a reflectivity memory, a system memory, a processor, an input device, a video card, a color display memory, and a reflection device of known reflectivity. The color display memory stores a first graphical interface and a second graphical interface. The first graphical interface displays a range of intensities of outputs that the display device can generate. The second graphical interface displays a range of hues that the display device can generate. The reflection device defines an aperture. The reflection device is compared to the first graphical interface and the second graphical interface by viewing the interfaces through the aperture. The present invention includes a method for compensating an output device for reflected ambient illumination.

Abstract: An apparatus and method are provided for automatically adjusting a pixel sampling clock frequency and phase of a video display to match the frequency and phase of a pixel clock used to generate an incoming video signal being received by the video display. Voltage transitions are detected between pixel intensities in a video signal. The voltage transitions are compared with pixel sampling clock pulse signals of the video display in order to correctly match the frequency and phase of the video signal, and thus produce a more stable and noise-free image on the video display.

Abstract: A system for compensating the output of an output device to eliminate reflected ambient illumination comprises a display device, a calibration memory, a reflectivity memory, a memory, a processor, an input device, a video card, and an achromatic card that serves as a standard for comparison to the output of the output device. The reflectivity memory stores the reflectivity characteristics of the output device. The calibration memory stores the optical characteristics of the output device. The memory stores the reflectivity characteristics of the achromatic card, data, and program instruction steps of the system. The output of the output device is adjusted to match the ambient illumination reflected from the achromatic card. The processor then determines the tristimulus values of the ambient illumination through the known tristimulus values of the output generated by the output device, the reflectivity characteristics of the achromatic card, and the reflectivity characteristics of the output device.

Abstract: A system and method achieve and maintain an accurate white point setting of a CRT display in a computing system. The CRT is initially calibrated by individually driving the individual color cathodes and by measuring tristimulus values and cathode beam current for each of the three primary colors. The tristimulus values are normalized by dividing each value by the beam current producing it, and the normalized values are then stored in a calibration memory contained in the display unit. A table of gamma values representing beam current as a function of video drive voltage is measured and also added to the calibration memory. Calibration of the display is implemented by driving the display controller with a white point value and calculating the cathode beam currents from the stored tristimulus values, required to produce an accurate CRT representation of the signal sent to the display controller.

Abstract: A circuit for reducing extremely low frequency (ELF) electric fields on cathode ray robe (CRT) devices comprises a power supply means, a CRT, a voltage sensing means, an amplification means, and a capacitive coupling within a feedback path to the CRT. A CRT anode voltage variation sensed by the voltage sensing means is amplified and inverted by the amplification means, producing a signal which is applied to the capacitive coupling within the feedback path. This signal modifies the impedance at the CRT anode, decreasing the voltage variation and thereby reducing ELF electric field magnitudes.