Abstract: There is provided a delta-sigma A/D converter including a first integrator, a second integrator located on an output side of the first integrator, a quantizer located on an output side of the second integrator, and a first current D/A converter receiving an output of the quantizer and providing a negative feedback signal to an input side of the quantizer.

Abstract: A switcher device comprises a multiplexer coupled in-between at least one input and output cards. The multiplexer detects the presence of an event signal from an activated sink. In response to the detection of the event signal, the switch dynamically switches to a closed position in order to enable the at least one source to authenticate with the input card and the output card to authenticate with the at least one sink for security protocol encryption. In response to the non-detection of the event signal, the switch switches dynamically to an open position in order to disable the at least one source from authenticating with the input card, therefore the output card also does not attempt to authenticate with the at least one sink for security protocol encryption.

Abstract: A switcher device comprises a multiplexer coupled in-between at least one input and output cards. The multiplexer detects the presence of an event signal from an activated sink. In response to the detection of the event signal, the switch dynamically switches to a closed position in order to enable the at least one source to authenticate with the input card and the output card to authenticate with the at least one sink for security protocol encryption. In response to the non-detection of the event signal, the switch switches dynamically to an open position in order to disable the at least one source from authenticating with the input card, therefore the output card also does not attempt to authenticate with the at least one sink for security protocol encryption.

Abstract: A switcher device comprises a multiplexer coupled in-between at least one input and output cards. The multiplexer detects the presence of an event signal from an activated sink. In response to the detection of the event signal, a processor changes an address of an HDCP receiver from a first address to a second address for enabling the at least one source to authenticate with the input card and enabling the output card to authenticate with the at least one sink for security protocol encryption. In response to the non-detection of the event signal, the processor changes the address of an HDCP receiver from the second address to the first address for disabling the at least one source from initiating a first authentication with the input card, therefore the output card also does not attempt to initiate a second authentication with the at least one sink for security protocol encryption.

Abstract: A display device includes a display panel, a light source module and a skin-color detector. The display panel has a plurality of sub pixel units, and the sub pixel units include red sub pixel units, green sub pixel units, blue sub pixel units and white sub pixel units. The light source module is disposed at a side of the display panel and the light source module includes a white light source and a yellow light source distributed in the white light source. The skin-color detector is electrically connected to the display panel, wherein the skin-color detector detects the skin-color area proportion of an image signal of the display panel.

Abstract: A display apparatus includes a signal input unit through which an image signal is input, the image signal comprising a synchronization signal and an active signal; an adjustment signal generating unit that generates an adjustment signal; a signal processing unit that receives the adjustment signal and adjusts the image signal based on the received adjustment signal; and a controller which analyzes the input signal and controls the adjustment signal generating unit to change characteristics of the adjustment signal if the adjustment signal does not lie within a blanking interval between the synchronization signal and the active signal. With this configuration, even when an image signal having a reduced blanking interval between the synchronization signal and the active signal is input, the adjustment signal can be generated within the blanking interval of the image signal, not within the active signal interval.

Abstract: Embodiments of the invention provide a circuit for peaking video signals to be provided to a dynamic range limiter for displaying images on a display device. The circuit comprises a peaking filter including a filter input configured to receive a video signal. A first filter output provides a peaking signal for the video signal. A second filter output provides a peaked video signal based upon the peaking signal. The circuit further comprises a throttle circuit including a throttle input coupled to the second filter output. A throttle output provides a throttle signal based upon the peaked video signal. A scaler is coupled between the first filter output and the dynamic range limiter. The scaler is further coupled to the throttle output. The scaler adjusts the peaking signal based upon the throttle signal.

Abstract: The invention relates to an image processing chip and related method. The image processing chip includes a pin for receiving a composite signal; a synchronization signal detecting circuit, coupled to the pin, for extracting a synchronization signal from the composite signal; a clamping circuit, coupled to the pin, for adjusting a voltage level of the composite signal according to the synchronization signal; and an analog to digital converter, coupled to the pin, for generating a video signal by sampling the composite signal.

Abstract: An image correction circuit capable of preventing a loss of gray levels in a luminance region at the time of the direct current level conversion of a luminance signal to improve the quality of a displayed image. The image correction circuit detects an average peak level of input image data in each image frame, and corrects the input image data to lower the luminance of input image data in an intermediate luminance region according to the average peak level while reducing the luminance of input image data at a predetermined rate in at least of a low luminance region.

Abstract: A slice level adjustment unit for performing adjustment of a slice level with respect to a signal whose transmission is started at a predetermined time, includes a clock portion for measuring the current time, and performs a first adjustment of the slice level when the clock portion measures substantially the predetermined time and also performs a second adjustment when the clock portion measures a readjustment standby time past the predetermined time.

Abstract: A liquid crystal display device includes a four-color conversion circuit with no chromatic changes in which the chromaticity and luminance of input image data are maintained, a four-color conversion circuit with chromatic changes in which the chromaticity and luminance of input image data are not necessarily maintained, and a selector for switching between the outputs from the two conversion circuits according to a level detection signal from a level detection circuit that detects whether the level of input image data is equal to 100% white level or higher. Display data from the selector is supplied to a liquid crystal section that displays an image by four-color pixels of red, green, blue, and white. The image data conversion circuit controls the light emission quantity of a backlight (BL) as white color, and converts input image data so that the level of data displayed on the liquid crystal section becomes uniform.

Abstract: A circuit and method for improving mismatches between signal converters includes at least two conversion units, a clock generator and a reference voltage generator. The conversion units share the clock generator and/or the reference voltage generator so as to improve mismatches between the conversion units.

Abstract: In the event that the maximum Imax of R, G, B color signals is detected and the maximum value Imax is equal to or higher than the suppression start level Vcs which is lower than a predetermined level to be restricted, a suppression gain is generated in accordance with the value of this maximum Imax, and by this suppression gain Gc, R, G, B color signals to be inputted are simultaneously suppressed. By this, color signals can be restricted to the predetermined range and outputted without impairing white balance.

Abstract: Disclosed herein is a video signal process circuit that includes a control circuit having a level detection circuit and a dynamic range switch circuit. In the control circuit and a microcomputer, an average luminance of an image displayed on a liquid crystal panel via a liquid crystal driver circuit is detected. When the average luminance is equal to or over a level YSmax, an upper limit of the dynamic range is expanded, so that a signal level of a composite video signal in which white blur can occur can be digitized to a digital signal without being limited by the upper limit gradation, reducing the white blur of the image to improve the quality of the image.

Abstract: The present invention has an object to provide a gradation correcting apparatus for correcting the gradation of the white side of a video luminance signal. The gradation correcting apparatus is provided with a maximum value detector 101 for detecting a maximum value of a luminance signal S101, a white comparator 102 for comparing the luminance signal S101, a maximum luminance value S111 detected by the maximum value detector 101, and a first white threshold value S103, a white linear converter 103 for performing linear conversion on the luminance signal S101 on the basis of the maximum luminance value S111, the first white threshold value S103, and a second white threshold value S104, and a white controller 104 for correcting the luminance signal S101 on the basis of the result of the comparison in the white comparator 102, the output of the white linear converter 103, and the second white threshold value S104.

Abstract: To provide an image processing system, projector, information storage medium and black and white extension processing method which can improve the quality of image when at least one of white extension and black extension is performed to video signals, a extension degree setting section is controlled by using a control section to change a degree of extension only when a change-over of scenes occurs, and luminance values of R-signals, G-signals and B-signals are extended toward one of white and black sides with the degree of extension set by the extension degree setting section by using extending sections and a luminance changing section.

Abstract: An interface circuit 13 is provided for a display apparatus 3 such as a television. The display apparatus 3 comprises a video signal processing circuit 8 for processing a composite video signal to derive color component signals having variable black and white levels; a linear amplifier 10 for amplifying the color component signals; and a display device 4 such as a CRT driven by the output of the linear amplifier 10. The interface circuit 13 is provided to interface the color component signals with a digital signal processor 14. The interface circuit 13 includes a modification circuit 22 arranged to perform a modification of voltage levels of the color component signals and to output the modified color component signals to the digital signal processor 14 via an A/D convertor 18.

Abstract: A drive circuit of an LCD is disclosed, by which no image signal having a voltage level over the dynamic range of the video amplifier, and thus erroneous operation of the video amplifier is prevented, thereby supplying normal image signals to the LCD. The drive circuit comprises a clip circuit for clipping the amplitude range of the voltage of a picture signal input from an input terminal; a polarity inversion circuit for receiving the picture signal whose amplitude range was clipped by the clip circuit, and for converting the picture signal so that an inverted signal and a non-inverted signal are alternately assigned to each dot; and a video amplifier for amplifying the voltage level of the converted picture signal by a predetermined amplification degree.

Abstract: A device and a method for automatically discriminating formats of video signals input to a monitor and processing the respective signals in accordance with the identified formats are provided. The device automatically identifies whether signals input to the same input port are RGB type PC signals or YPbPr type HDTV signals and processes the signals in accordance with the identified formats. Therefore, users have only to install a single input port commonly used to receive PC signals and HDTV signals rather than installing separate input ports for separately receiving PC signals and HDTV signals.

Abstract: A video signal processing apparatus includes a receiver receiving an incoming video signal and producing an output video signal in response thereto, a limit setup unit setting up at least one of an upper limit value and a lower limit value for the output video signal, and a limiter supplied with the output video signal from the receiver and further with at least one of the upper limit value and the lower limit value from the limit setup unit, wherein the limiter limits a level of the output video signal produced by the receiver, by comparing the level of the output video signal according to any of the upper limit value and the lower limit value.

Abstract: A video signal processing apparatus includes a receiver receiving an incoming video signal and producing an output video signal in response thereto, a limit setup unit setting up at least one of an upper limit value and a lower limit value for the output video signal, and a limiter supplied with the output video signal from the receiver and further with at least one of the upper limit value and the lower limit value from the limit setup unit, wherein the limiter limits a level of the output video signal produced by the receiver, by comparing the level of the output video signal according to any of the upper limit value and the lower limit value.

Abstract: A video signal processing apparatus includes a receiver receiving an incoming video signal and producing an output video signal in response thereto, a limit setup unit setting up at least one of an upper limit value and a lower limit value for the output video signal, and a limiter supplied with the output video signal from the receiver and further with at least one of the upper limit value and the lower limit value from the limit setup unit, wherein the limiter limits a level of the output video signal produced by the receiver, by comparing the level of the output video signal according to any of the upper limit value and the lower limit value.

Abstract: A video signal processing apparatus includes a receiver receiving an incoming video signal and producing an output video signal in response thereto, a limit setup unit setting up at least one of an upper limit value and a lower limit value for the output video signal, and a limiter supplied with the output video signal from the receiver and further with at least one of the upper limit value and the lower limit value from the limit setup unit, wherein the limiter limits a level of the output video signal produced by the receiver, by comparing the level of the output video signal according to any of the upper limit value and the lower limit value.

Abstract: An image quality correction circuit having a variable gain amplifier for amplifying an extracted high-frequency component of a luminance signal in such a manner that the gain thereof is increased when detected color density is high, and is reduced when the detected color density is low, and a slice circuit for slicing the outputted amplitude of the variable gain amplifier at a prescribed value, wherein a corrected luminance signal is obtained by combining an image quality correction signal outputted from the slice circuit with the luminance signal to be corrected.

Abstract: Red color saturation is increased and red color with higher purity can be reproduced by composing: a red color detection circuit 1 for detecting a red color signal having higher purity by inputting color differential signals (R-Y) and (B-Y) modulated by color subcarrier, subtracting the absolute value of the (B-Y) signal from the positive polarity component of the (R-Y) signal and removing the negative part of the subtracted signal; Y signal compensation block including: first gain controller 50b for controlling the output signal amplitude of red color detection circuit 1 and a subtracter 50a for subtracting the output signal of first gain controller 50b from a luminance signal Y; an (R-Y) signal compensation block including: second gain controller 51b for controlling the output signal amplitude of red color detection circuit 1 and an adder 51a for adding the output signal of second gain controller 51b and the input (R-Y) signal; and a (B-Y) signal compensation block including: third gain controller 52b for c

Abstract: An image quality correction circuit having a variable gain amplifier for amplifying an extracted high-frequency component of a luminance signal in such a manner that the gain thereof is increased when detected color density is high, and is reduced when the detected color density is low, and a slice circuit for slicing the outputted amplitude of the variable gain amplifier at a prescribed value, wherein a corrected luminance signal is obtained by combining an image quality correction signal outputted from the slice circuit with the luminance signal to be corrected.

Abstract: A primary color video output circuit for limiting an input video signal. The circuit includes a clipping circuit, a reference voltage generating circuit and an amplifier. The clipping circuit limits the level of the input video signal based on a reference voltage generated by the reference voltage generating circuit. The amplifier is then used to amplify the clipped video signal.

Abstract: An image quality correction circuit having a variable gain amplifier for amplifying an extracted high-frequency component of a luminance signal in such a manner that the gain thereof is increased when detected color density is high, and is reduced when the detected color density is low, and a slice circuit for slicing the outputted amplitude of the variable gain amplifier at a prescribed value, wherein a corrected luminance signal is obtained by combining an image quality correction signal outputted from the slice circuit with the luminance signal to be corrected.

Abstract: An image quality correction circuit having a variable gain amplifier for amplifying an extracted high-frequency component of a luminance signal in such a manner that the gain thereof is increased when detected color density is high, and is reduced when the detected color density is low, and a slice circuit for slicing the outputted amplitude of the variable gain amplifier at a prescribed value, wherein a corrected luminance signal is obtained by combining an image quality correction signal outputted from the slice circuit with the luminance signal to be corrected.

Abstract: A method and apparatus for processing image data comprising the steps of extracting white component data from input R, G, B color data, suppressing the white component data in accordance with a non-linear characteristic, generating R, G, B, W display data and driving a liquid crystal display panel having R, G, B, W filters in accordance with the R, G, B, W display data in order to display a full color image.

Abstract: An image quality correction circuit having a variable gain amplifier for amplifying an extracted high-frequency component of a luminance signal in such a mariner that the gain thereof is increased when detected color density is high, and is reduced when the detected color density is low, and a slice circuit for slicing the outputted amplitude of the variable gain amplifier at a prescribed value, wherein a corrected luminance signal is obtained by combining an image quality correction signal outputted from the slice circuit with the luminance signal to be corrected.

Abstract: A video amplifier includes three amplifier circuits (TR, TG, TB) for the red, the green and the blue signals which are each provided with a different feedback signal which changes value when the signal exceeds a certain threshold, by a feedback resistor circuit having two cascade-arranged resistors (R4R in cascade with ?R1+R2+R3!), with their central junction being connected by a diode (Tth) to a fixed voltage (DZ). The ratio value between the two cascade-arranged resistors is different between the amplifier circuits, and moreover, a part (R1 or ?R1+R2!) of the resistor at the base of a cascade arrangement of resistors may be common for several amplifier circuits.

Abstract: A video signal clamping circuit for maintaining a constant clamping output level is disclosed including a clamper for generating a clamping output level in response to a reference voltage by use of an external condenser receiving a video signal and a plurality of transistors, a level variation detector for sensing a variation the clamping output level of the clamper and generating a level variation signal corresponding to the variation in the clamping output level, and a reference voltage compensator connected to the level variation detector, for receiving the level variation signal and compensating for the reference voltage of the clamper.

Abstract: A white clip circuit, formed as an integrated circuit, includes a negative impedance converter which in use is operative to increase the sensitivity of an inverting long-tailed pair of transistors adapted to invert the signals and feed them back to the input in order to control the clip level and to enable it to be effective at a relatively low level.

Abstract: An image quality correction circuit having a variable gain amplifier for amplifying an extracted high-frequency component of a luminance signal in such a manner that the gain thereof is increased when detected color density is high, and is reduced when the detected color density is low, and a slice circuit for slicing the outputted amplitude of the variable gain amplifier at a prescribed value, wherein a corrected luminance signal is obtained by combining an image quality correction signal outputted from the slice circuit with the luminance signal to be corrected.

Abstract: Cost effective video clipping circuitry and method achieve lower distortion color television broadcasting. Excess "white" level voltage peaks in otherwise standard (e.g., that of the National Television Standards Committee) color line video signals are clipped by a unique arrangement to prevent over-modulation of an RF broadcast carrier. The circuitry includes amplifier circuitry for substantially amplifying a line video signal above standard levels, diode clipping circuitry for clipping excess white levels from the signal after it has been amplified thereby reducing distortion otherwise caused by an inherent non-linear initial conduction characteristic of the diode clipping circuitry, and attenuator circuitry for attenuating to standard levels the signal after clipping so as to obtain reduced luminance and chrominance distortion.

Abstract: An image quality correction circuit having a variable gain amplifier for amplifying an extracted high-frequency component of a luminance signal in such a manner that the gain thereof is increased when detected color density is high, and is reduced when the detected color density is low, and a slice circuit for slicing the outputted amplitude of the variable gain amplifier at a prescribed value, wherein a corrected luminance signal is obtained by combining an image quality correction signal outputted from the slice circuit with the luminance signal to be corrected.

Abstract: The white peak level and black peak level of each of three types of color signals R, G and B obtained by picking up a negative image are detected. The amplitudes and levels of the signals are adjusted in such a manner that the white peak levels of the color signals R, G and B coincide as well as the black peak levels of these color signals. Signals representing the detected white peak and black peak levels are superimposed in first-half and second-half portions of a blanking interval of each of the color signals R, G and B. The signals that result can be utilized in subsequent signal processing. Also, the input/output characteristics of a gamma correction circuit are represented by an exponential function, which is for a gamma correction, up to a fixed input range, and by a KNEE curve, whose slope is smaller than that of the exponential curve, in a range beyond the fixed input range.

Abstract: A circuit arrangement for adaptive white-compression of video signals of a color television apparatus, particularly of a HDTV picture signal generator, which has a signal minimum detector circuit (4, 5, 6) in each color channel. Input color signals (R, G, B) as well as a compressed color signal are applied to these detector circuits, while the smaller of the two input signals can be derived from their outputs. The compressed color signals are generated by digitally controlled multiplier circuits (14, 15, 16). The digital control signal for these multiplier circuits is generated by controlling an up/down counter (24) by a digitized steering signal derived from the video output signals by line-sequential measurement and comparison with a threshold value reference signal.

Abstract: A video signal peak compressor circuit includes an emitter follower stage together with a feedback amplifier having a conduction threshold determined by a pair of voltage divider resistors. The feedback amplifier responds to increased conduction of the emitter follower stage to apply a compensating current to the emitter follower base and thereby impose a nonlinear compressing characteristic upon the emitter follower transfer function. In the embodiment shown, the emitter follower stage includes a PNP transistor having an input signal applied to its base and an output signal taken at its emitter which is coupled to operating supply by a pair of resistors. The feedback amplifier includes a PNP transistor having its emitter coupled to the junction point of a voltage divider, its base coupled to the junction of the emitter follower resistors and its collector coupled to the base of the PNP emitter follower stage.

Abstract: A video white compression and peaking arrangement comprises a plurality of inverting amplifier transistors each tied to a common threshold level. RGB input video signals are applied to the inverting amplifier transistors which are ineffective for signals below the threshold level. The transistors are progressively turned on for input signals that exceed the threshold level resulting in non-linear negative feedback signals that compress the output signals by subtraction. A tuned circuit is coupled across the input of each inverting amplifier transistor for bypassing selected frequencies from the negative feedback effect and relatively peaking those frequencies in the output signal.

Abstract: A limiter circuit responds to an input signal which has a plurality of frequencies within a given band. The input signal is split up into two frequency ranges by means of a low pass filter for one range and a high pass filter for a second range. The output of the low pass filter is directed to a first limiter while the output of the high pass filter is directed to a variable notch filter. The outputs from the first limiter and the notch filter are added together to provide a sum signal. The sum signal is applied to a second limiter which performs limiting strictly according to the amplitude. The outputs of the second limiter signal provide the desired signal and a control signal to determine how often the second limiter is limiting. The control signal varies the attenuation of the notch filter. In this manner frequencies, within a selective range and which will be otherwise effected by the spurious frequencies generated during limiting, are reduced.

Abstract: A video camera is comprised of an aperture correcting signal generating circuit for generating an aperture correcting signal from a video signal of a picked-up image, and a nonlinear processing circuit for comparing the video signal with a reference voltage modulated by the aperture correcting signal and compressing the video signal at its high brightness portion higher than the reference voltage when the video signal is higher than the reference voltage.

Abstract: Red color saturation is increased and red color with higher purity can be reproduced by composing: a red color detection circuit 1 for detecting a red color signal having higher purity by inputting color differential signals (R-Y) and (B-Y) modulated by color subcarrier, subtracting the absolute value of the (B-Y) signal from the positive polarity component of the (R-Y) signal and removing the negative part of the subtracted signal; Y signal compensation block including: first gain controller 50b for controlling the output signal amplitude of red color detection circuit 1 and a subtracter 50a for subtracting the output signal of first gain controller 50b from a luminance signal Y; an (R-Y) signal compensation block including: second gain controller 51b for controlling the output signal amplitude of red color detection circuit 1 and an adder 51a for adding the output signal of second gain controller 51b and the input (R-Y) signal; and a (B-Y) signal compensation block including: third gain controller 52b for c