Signal processors for permitting the transparent, simultaneous transmission and reception of a data signal in the video bandwidth is disclosed. The signal processor in the transmitter rasterizes the data at the horizontal scanning rate and modulates the data with a data carrier at a non-integral multiple of the horizontal scanning rate to obtain frequency interleaving. The data is transmitted during the active video portion of each video line.

Data with video transmitter

Signal processors for permitting the transparent, simultaneous transmission and reception of a secondary data signal with a video signal in the video band is disclosed. The signal processor in the transmitter rasterizes the data at the horizontal scanning rate and modulates the data with a data carrier at a non-integral multiple of the horizontal scanning rate to obtain frequency interleaving. The data is transmitted during the active video portion of each video line.

System for transparent transmission and reception of a secondary data signal with a video signal in the video band

A secondary signal is processed and injected into a primary video signal. The injection level of the secondary signal is dynamically controlled to reduce transmission errors in the secondary signal, and to minimize interference and power level limitations. The injection level of the secondary signal may be based on video analysis of the primary signal or on error information fed back from a receiver which receives the transmitted secondary signal.

Transmitting a secondary signal with dynamic injection level control

A controlled element for spectrum attenuation or a controlled filter is disclosed that is used to aid in the insertion of a secondary signal into a video signal without distorting the blanking intervals or close captioned data contained in the blanking interval of the video signal.

Filter by-pass for transmitting an additional signal with a video signal

A position detecting device includes a sensor having electrodes that receive an alternating current (AC) signal from a capacitive stylus pen that transmits the AC signal. The position detecting device detects a position indicated by the stylus pen on the sensor. The position detecting device also includes: an electrode selection circuit that selects electrodes provided in the sensor for connection to a positive terminal and a negative terminal; a differential amplifier that amplifies and outputs a signal indicating a difference between signals generated at the positive terminal and the negative terminal; a height detector that obtains a height of the stylus pen relative to a sensor surface of the sensor; and a control unit that causes a selection pattern of the electrodes selected for connection to the positive terminal and the negative terminal by the electrode selection circuit to change according to the height obtained by the height detector.

Position detecting device and position detecting method

In a circuit arrangement for synchronization of the phase of a frequency-divided signal with an edge of finite slope of an essentially periodic synchronizing signal with an oscillator supplying a clock signal, a frequency divider which generates the frequency-divided signal and a phase detector which comprises a first comparator for coarse phase detection, a second comparator for fine phase detection and a selector circuit which derives a resulting phase signal applied to the oscillator to control the frequency of the clock signal and originating from the first comparator in the case of large phase variations and from the second comparator in the case of small phase variations, precise adjustment to the edge is nevertheless achieved in the case of an amplitude-discrete synchronizing signal with limited time resolution because of the fact that the synchronizing signal is applied to the phase detector as a sequence of amplitude-discrete values which is formed by sampling the synchronizing signal with the clock signal, a sufficient number of amplitude stages being provided for the edge in the synchronizing signal.

Circuit arrangement for synchronization of a signal

The invention relates to a circuit arrangement for increasing the resolution of color contours. A slope detector detects the slope of the luminance signal and, when a predetermined slope value is exceeded, produces a detection signal for energizing a counter. The counter controls an edge enhancement circuit for a color difference signal, in which, as soon as the counter is energizing, the value of the color difference signal is stored and is available as an output signal. After a predetermined number of equidistant clock pulses has been counted, the edge enhancement circuit (7, 16) supplies the actual color difference signal value. If before the end of the counting operation, a new detection signal is produced, then the edge enhancement circuit briefly receives and stores the actual color difference signal value, and the counter starts a new counting cycle.

Circuit arrangement for increasing the definition of color contours of a color television signal using selective edge enhancement

A circuit arrangement for a television receiver including a video text decoder (30), producing signals from the video text data from which control signals for a picture display device can be derived. The circuit arrangement further including a television signal decoder (1), deriving from the television signal via a low-pass filter arrangement (15) the luminance signal which can be taken from the luminance signal output (18). The low-pass filter arrangement (15) has a first attenuation characteristic for suppressing the chrominance signal and a second attenuation characteristic for allowing all video text data to pass. The second attenuation characteristic of the low-pass filter arrangement (15) is used during the period of time in which the video text data occur. The input of the video text decoder (30) is coupled to the luminance signal output (18) of the television signal decoder (1).

Circuit arrangement for a television receiver comprising a video text decoder

Schaltungsanordnung zum Erhoehen der Schaerfe von Farbkanten

In einer Schaltungsanordnung zum Erhohen der Scharfe von Farbkanten detektiert ein Steilheitsdetektor (2l) die Steilheit des Helligkeitssignals und gibt ein Detektionssignal bei Uberschreitung eines bestimmten Steilheitsbetrages zur Aktivierung eines Zahlers (28) ab. In a circuit arrangement for enhancing the sharpness of color edge a slope detector (2l) detects the slope of the luminance signal and outputs a detection signal if it exceeds a certain slope amount for activating a counter (28) from. Der Zahler (28) steuert eine Versteilerungsschaltung (7, l6) fur ein Farbdifferenzsignal, in der zu Beginn der Aktivierung des Zahlers (28) der Wert des Farbdifferenzsignals gespeichert wird und als Ausgangssignal verfugbar ist. The counter (28) controls a peaking (7, l6) of the value of the color difference signal is stored for a color difference signal in which the start of activation of the counter (28) and is available as an output signal. Nach der Zahlung einer bestimmten Anzahl von aquidistanten Takten gibt die Versteilerungsschaltung (7, l6) wieder den aktuellen Farbdifferenzsignalwert aus. After the counting of a certain number of equidistant strokes are the peaking (7, l6) again the current color difference signal value. Wird vor Ende der Zahlung ein neues Detektionssignal erzeugt, so beginnt der Zahler (28) mit einer neuen Zahlung. If a new detection signal is generated before the end of the count, the counter (28) starts a new count.

Detlef Oldach

Papers

Circuit arrangement for synchronization of a signal

Circuit arrangement for increasing the definition of color contours of a color television signal using selective edge enhancement

Circuit arrangement for a television receiver comprising a video text decoder

Schaltungsanordnung zum Erhoehen der Schaerfe von Farbkanten

Circuitry for increasing the sharpness of colour edges