Abstract: A video signal processing device comprising an operating element array for processing video signals according to commands given from the outside, memories for temporarily storing the video signals according to commands given from the outside, and a network 3 for connecting the operating element array and the storage units according to commands given from the outside, thereby making it possible to switch ways of processing digitized video signals according to commands from the outside.

Abstract: A recording/reproducing device including a recording/reproducing unit for recording/reproducing TV signals, and input device for inputting second signals of a system other than the TV signal system and a converter capable of converting the second signals into the same as signals at the TV signal recording time, wherein the second signals is capable of being recorded by the converter.

Abstract: A system for converting from an image with one aspect ratio to another aspect ratio includes a plurality of simple converters and a selector which selects one of the plurality of converters to convert from one image size to another. The selector divides the image into a plurality of pixel portions and establishes a rule to select the appropriate converter for each of the plurality of pixel portions.

Abstract: Radio receivers for receiving DTV signals, in accordance with the Advanced Television Systems Committee (ATSC) standard, or analog TV, in accordance with the National Television Sub-Committee (NTSC) standard, each use a single first detector for both types of signal. This single first detector supplies its output signals to an intermediate-frequency amplifier chain for DTV signals and to another intermediate-frequency amplifier chain for analog TV signals. The response of the intermediate-frequency amplifier chain for DTV signals is synchrodyned to baseband and supplied to symbol decoding circuitry. The response of the intermediate-frequency amplifier chain for analog TV signals is supplied to a video detector. In some of the radio receivers the sound carrier of the NTSC signal has a separate, further intermediate-frequency amplifier chain. The intermediate-frequency chain for DTV signals comprises an intitial portion which has reverse AGC, a following mixer, and a final portion which also has reverse AGC.

Abstract: An automatic channel responsive television input source selection switch couples output signals from a selected one of a plurality of input television input source interface circuits to a television in accordance with a user channel selected with a user channel selector manually controlled through one of a remote control unit and interface and a manual interface. A look-up table memory stores each of the possible user channel numbers along with an associated input signal source channel and an indication of signal source identity, such as indication of a direct broadcast satellite television signal source, a public television broadcast source and a security camera source. The switch based on the associations stored in the look-up memory selects the associated video input signal source and provides an indication of the associated source channel number to a tuner included in the selected interface.

Abstract: A multisystem TV which is usable as a monitor of a personal computer (PC).

Abstract: An apparatus and method for reproducing a video signal of a digital video disk. The method includes the steps of checking a television mode; if the television mode is a PAL system, selecting a video processor in a PAL mode and checking a video signal mode recorded in the disk; and if the video signal recording mode is an NTSC system, selecting a video decoder in an NTSC mode so as to supply a pseudo PAL video signal to a television.

Abstract: A system detects the presence of NTSC co-channel interference and enables NTSC comb-filtering when the NTSC signal is detected. The system comb-filters the baseband signal to generate a filtered baseband signal, and accumulates the noise power of the baseband and filtered baseband signals. The noise power of the baseband and filtered baseband signals is compared by forming a difference between the two noise powers, and the system detects the NTSC signal when the difference exceeds a threshold T. The threshold T is related to a product of a signal power of the baseband signal and a minimum carrier to noise ratio for the ATSC system.

Abstract: When both a progressive scanning video signal (for example, telecine signal) and an interlace scanning signal are present, the telecine signal is processed with pulldown information. The interlace scanning signal is processed without the pulldown information. Thus, even if both a telecine signal and a conventional interlace scanning signal are present, the pulldown information can be effectively used.

Abstract: A method of and apparatus for identifying a signal transmitting source detects a switching of a signal on the reception side thereby to prevent a transmission error from occurring when a signal is switched. The apparatus for identifying a signal transmitting source comprises a transmitting source identifying code extracting circuit for extracting a transmitting source identifying code provided in a SDDI format header of a received signal, a preceding transmitting source identifying code holding circuit for detecting a change of the transmitting source identifying code, and a transmitting source identifying code comparing circuit for detecting a switching of a transmitted signal based on the transmitting source identifying code thus changed, thereby detecting a switching of the transmitting source.

Abstract: The data field synchronization segment as symbol coded for VSB transmission comprises pseudo-random noise (PN) sequence information that can be detected using a match filter in a QAM/VSB DTV signal receiver. The data field synchronization segment as symbol coded for QAM transmission does not contain the PN sequence information that can be detected using the same match filter used for detecting the PN sequence information in the VSB transmission. A threshold detector is used for determining whether the match filter response is of sufficient energy to indicate occurrence in a received DTV signal of the PN sequence information in the data field synchronization segment of a VSB DTV transmission. Timed latch circuitry is used for latching the indication for a period of time longer than at least one DTV data field. The QAM/VSB DTV signal receiver is operated either in a QAM reception mode or in a VSB reception mode, depending on the output signal of the timed latch circuitry.

Abstract: Apparatus and method for converting a video received in a digital TV to process video data with different formats using the same ports. The apparatus and method includes a process to convert the video data from one format to another format and a process to convert the sync signals of one video format to correspond to the sync signals of another video format. Thus, different videos such as NTSC or VGA signals can be interfaced using signals of a small number of ports, thereby to reducing an overall size of the necessary hardware.

Abstract: A color system determination circuit for use with an input video signal having a frequency component is disclosed. The circuit includes a color trap filter for attenuating the frequency component in the input video signal with the color trap filter providing a color burst output signal, a comparator for comparing the color burst output signal of the color trap filter and the frequency component of the input video signal, a maximum value detector which receives the color burst output signal of the color trap filter and a color burst sampling signal and detects a maximum value of the color burst output signal of the color trap filter during a period of the color burst sampling signal, and another maximum value detector which receives the video signal and the color burst sampling signal and detects a maximum value of the video signal during the period of the color burst sampling signal.

Abstract: There is provided a multi-receiving demodulator for receiving broadcasting signals from multiple broadcasting systems. The multi-receiving demodulator has a first band pass filter for selectively band-pass-filtering an intermediate frequency output from a tuner to obtain a color subcarrier corresponding to the broadcasting system of a received signal, according to a first control signal, and a second band pass filter for selectively band-pass-filtering the intermediate frequency output from the tuner to obtain an audio carrier corresponding to the broadcasting system of the received signal, according to a second control signal. A video demodulating portion receives the color subcarrier from the first band pass filter and selectively demodulates a video signal corresponding to the broadcasting system of the received signal in accordance with the second control signal.

Abstract: A television converter uses digital signal processing (DSP) to provide compatibility with different television standards including NTSC and PAL video standards and FM, BTSC, DIN, Home Theatre, NICAM and independent digital audio standards. Audio processing is accomplished without passing the audio through a Nyquist filter used for video. This eliminates AM to PM conversion improving luminance linearity and differential gain and phase. It also prevents video information from phase modulating the audio intercarrier, thereby eliminating video "buzz" components in the audio. The audio processing includes a synchronous FM demodulator and a separate synchronous FM/QPSK demodulator for handling the different audio standards. Handling historical analog TV standards with DSP also enables the advantageous combination of analog and digital television reception within a single digital VLSI ASIC.

Abstract: A multi-standard television receiver in accordance with the present invention includes a plurality of video signal processing blocks having tristate functions at their output terminals, at least one memory block used in common for a plurality of video signal processing blocks and a video signal processing selection means for selecting one of the video signal processing blocks and independently controlling the output terminals of the video signal processing blocks using elements having a tristate function and can reduce power consumption by working only a selected video signal processing block and stopping the other video signal processing blocks. Further, using elements having a tristate function, possibility of element breakdown at selection and control of the elements can be removed.

Abstract: A waveform monitor receives HDTV and SDTV signals that are provided to a channel and an external trigger terminal respectively. An HDTV signal processor 14 produces a reference clock PCLK from the HDTV signal. A counter starts counting at the vertical sync signal of the SDTV signal and generates a trigger every time the count of the reference clock PCLK reaches a predetermined number (2,200, for example). This allows generation of a trigger signal which is phase locked to the vertical sync signal of the SDTV signal, and of which the frequency is the same as the horizontal line frequency of the HDTV signal. Therefore the waveform monitor can display the HDTV waveform line by line even though the HDTV and SDTV signals have different numbers of lines per field. The waveform monitor can be used to measure phase difference between television signals of difference formats, such as the HDTV and the SDTV.

Abstract: A multi-standard receiver is which is particularly suited for reception of B/G-PAL and D/K-PAL TV signals. In the receiver, a tuner (TUN) selects a desired TV signal which is passed to a multi-standard demodulator (DEM) via an intermediate-frequency filter circuit (IFF). To obtain good performance, particularly in view of EN 55020 requirements, at moderate costs, the intermediate-frequency filter circuit (IFF) includes a main filter (FIL1) and an auxiliary filter (FIL2). The main filter (FIL1) may have a relatively narrow band, for example, just capable of passing a full B/G-PAL TV IF signal to the demodulator circuit. For D/K-PAL reception, the auxiliary filter (FIL2) is effectively switched (SW) in parallel with the main filter (FIL1). The auxiliary filter (FIL2) transfers the D/K-PAL sound carrier to the demodulator circuit (DEM), which transfer is not possible via the relatively narrow-band main filter (FIL1).

Abstract: A versatile video transformation device and adaptive image processing methodology thereof to digitally scan convert, that is, reformat TV raster scan video and particularly high definition (HD) and/or digital DTV (particularly those for example in 1920.times.1080i or 1280.times.720p format) video data and associated synchronizing signals, for the purpose of making present standard television sets compatible at low cost with the latest advancements in free HD whilst allowing a multitude of other DTV programs and ancillary data to fill to a greater extent the remaining channel allocations by FCC to TV broadcasters.

Abstract: A multiple format video signal processing system operating in conjunction with a display device timing system to produce synchronized video and timing signals suitable for use by a fixed horizontal scanning frequency display device.

Abstract: A communication control system capable of lessening burden (load) of the repeater and reducing the number of development steps of the system. Data of the ATM standard delivered to an ATM/1394 repeater 3 through an ATM network 2 from an ATM terminal 1 is converted into data of the IEEE 1394 standard by an ASEL 31. The data thus obtained is transmitted to a 1394 terminal 4. The data of the IEEE 1394 standard transmitted to the 1394 terminal 4 is converted into data of the ATM standard by an ASEL 32.

Abstract: A receiver which receives both HDTV and NTSC signals, and a method for selecting received signals, are provided. According to this receiver and method, a broadcasting mode and a channel mode are set by the user. When the broadcasting mode is set to be an NTSC mode, only an NTSC signal is selected to be displayed. When the broadcasting mode is set to be an HDTV mode, only a high-definition (ATV) signal is selected to be displayed. When the judged broadcasting mode is an automatic mode, a judgement is made by the receiver whether an NTSC signal exists in a received signal. If no NTSC signal is present in the received signal, the ATV signal is selected for display. If the NTSC signal exists in the currently-received signal, selection between NTSC and ATV signals is made based on the channel mode set by the user. If the channel mode is set to NTSC, then the NTSC signal is selected for display. If the channel mode is set to HDTV, then the ATV signal is selected for display.

Abstract: A digital television signal receiver includes a data slicer for symbol decoding and match filtering to recover data synchronizing information from the symbol decoding results. The match filtering comprises a shift register for receiving as serial input thereto the parallel-bit-groups of symbol decoding results from the data slicer and respective decoders for the serial input signal to the first of a number of successive stages of the shift register and for the output signal of each stage in that number of successive stages. The decoder results are combined using an AND gate when match filtering is performed to detect data segment synchronization symbol code sequences. In other match filtering the decoder results are combined using a digital adder network, and a threshold detector responds to the summed decoder results exceeding a threshold value to detect data field synchronization symbol code sequences.

Abstract: The following means are integrated in one IF IC: the switching part 60 in the video signal passage for changing over a plurality of sound trap circuits and equalizing circuits 61-64; the switching part 66 in the sound signal passage for changing over a plurality of band-pass filters 67-70 to pass the intercarrier signals of different frequencies; the switching parts (77A, 77B, 78) for adjusting the gains to regulate the difference of sound signal level caused by different frequency modulation degree of each broadcasting system to the constant level and for changing over deemphasis time constant. In addition, the same IF IC contains the FM demodulating circuit 80 of PLL system to demodulate the sound intercarrier and the controller 81 for controlling the changeover of switching parts 60, 66, 78. As a result, the IF IC of very high integration density has been achieved, and the number of components of IF signal processing circuit can be decreased.

Abstract: In a receiver having both an analog video service mode and a digital video mode, when the analog video mode is selected according to a mode selection signal indicating that a television channel is for the analog video mode or the digital video mode, a large-capacity memory used for the digital video-decoding may also be used as a frame memory for Y/C separation and post-processing, for enhancing picture quality, improving the efficiency of the memory and reducing the cost of a system.

Abstract: A video adapter circuit for adapting analog video signals provided by a personal computer system designed to drive a CRT display monitor into signals appropriate for driving a flat panel display monitor. The video adapter circuit accepts analog video and synchronizing signals in any one of several scanning formats commonly utilized in personal computer systems and automatically detects the scanning format of the signals. An oscillator generates a clock signal that is synchronized with the HSYNC signal generated by the personal computer system. Each of the analog RGB video signals are amplified by a video amplifier and sampled, according to the clock signal, by a digital-to-analog converter. A controller circuit compresses the sampled video signals and stores the compressed data in a dual-port video frame memory at a rate determined by the scanning format.

Abstract: In an HDTV receiver which can be used with both an 8-VSB (Vestigial Side Band) system and a 16-VSB system, since there are so many common modulation parts which are commonly operated between the two systems, an operation mode is automatically switched by using the autocorrelation of the operation modes of the received data without requiring manual operation, and signals for controlling the entire system are thereby realized efficiently and economically in operating the HDTV receiver.

Abstract: A video signal switching circuit according to the present invention provides a video signal switching circuit to thereby display various kinds of video signal by using a monitor.In addition, a video/audio signal switching circuit and method according to the present invention can selectively output a TV audio signal, a VCR audio signal and PC audio signal in a monitor including TV reception and video functions, to thereby reduce loads of the body of a multimedia computer.

Abstract: A monitor output device in an HDTV. The monitor device includes an HD decoder, a format converter, an HD/NTSC converter, and luminance and color output terminals for monitor output. The HD decoder decodes an HD signal of an HDTV broadcast which has been channel-selected and converted to a baseband signal, and outputs an HD video signal. The format converter converts the HD video signal of the HD decoder to an output color signal of a predetermined display type. The HD/NTSC converter converts the output color signal of the format converter to analog NTSC luminance and color signals, and outputs the luminance and color signals to the luminance output terminal and the color output terminal, respectively.

Abstract: A method and apparatus in a client processing system are provided for characterizing an input television signal as broadcast television or cable television and, if the signal is cable television, as IRC cable, HRC cable, or standard cable. The client processing system includes processing circuitry configured to receive hypertext pages from a remote server and to display the hypertext pages on a display device, such as a conventional television set. The client system further includes a television tuner for receiving either cable television or broadcast television signals. When a television signal is initially provided to the client system, the client system executes a routine to automatically characterize the received television signal as broadcast, HRC cable, IRC cable, or standard cable. The characterization is made based upon one or more frequencies at which the incoming television signal is detected.

Abstract: Radio receivers for receiving DTV signals, in accordance with the Advanced Television System Committee (ATSC) standard, or analog TV, in accordance with the National Television Systems Committee (NTSC) standard, each use a single first detector for both types of signal. This single is followed with an intermediate-frequency amplifier providing amplification both for digital television signal and for the amplitude-modulated NTSC video carrier of an analog television signal. Preferably, the shared intermediate-frequency amplifier is a high-band intermediate-frequency amplifier having fixed gain and having its bandwidth determined using a surface-acoustic-wave filter with flat-amplitude midband response, steep-slope skirts, and linear phase throughout its passband.

Abstract: A video processing system that automatically adjusts video processor parameters depending upon the format of a received video signal in, e.g., a television receiver capable of receiving a multiplicity of video formats.

Abstract: Disclosed is a synchronization circuit that can be applied in the field of monitors and, especially, in the field of television receivers. The disclosed circuit comprises circuits to analyse and correct the horizontal and vertical synchronization signals in order to neutralize the effect of the signalling present in the horizontal synchronization signal on the working of a phase-locked loop.

Abstract: An automatic gain control (AGC) circuit of a high definition television (HDTV) signal receiver and a method to compensate for a change in amplitude of a high definition signal. The AGC circuit of the high definition signal receiver includes a non-coherent AGC signal generator for generating a first AGC signal according to the magnitude of the IF signal, a coherent AGC signal generator for generating a second AGC signal according to the magnitude of the segment synchronizing signal, and a selector for selecting the second AGC signal when the segment synchronizing signal is detected and the first AGC signal when the segment synchronizing signal is not detected and providing the selected signal to a tuner/IF demodulator.

Abstract: A method of displaying a present display mode includes the steps of: detecting a changing of display node; checking a status set for using of default information; determining a present display mode considering optimize; and displaying a information of the present display mode for a pre-determined time.

Abstract: Digital broadcast receiving terminal apparatus which receives multi-channel digital broadcast signals to record the huge capacity without deteriorating the quality of signals and to visualize the digital broadcasting. The outputs form the error correction decoding circus 4 are applied to the TS processor 12 via the switches SW 1 and SW 2, at the same time they are applied to the recording program selector 11. The recording program selector 11 applies the encoded data of the predetermined program to the digital interface 13, the digital interface 13 inputs and outputs the encoded data through bus in the IEEE1394 specification for example. Thus, the encoded data are applied to the external equipment and recorded as they are, and the degradation of the quality can be prevented. The switches SW 1 and SW 2 changes the receiving signals and the outputs from the digital interface 13 and applies them to the TS processor 12. The TS processor 12 depacketizes the input encoded data.

Abstract: A receiver for receiving reception signals of a first type, for example, TV signals, and reception signals of a second type, for example FM-radio signals, is described. The receiver may be used in multimedia applications. In the receiver, an input section TVIN,FMIN,SWIN includes at least two inputs TVIN,FMIN to which reception signals can be applied. One input TVIN may, for example, be coupled to a cable network via which reception signals are distributed. The other input FMIN may, for example, be used to plug-in a simple wire antenna. In many cases, such a wire antenna will be sufficient to receive on-air reception signals with acceptable quality. The invention takes into consideration that on-air reception signals may not always be offered by the cable network. With at least two inputs TVIN,FMIN, there is flexibility of reception.

Abstract: In a receiver having both an analog video service mode and a digital video mode, when the analog video mode is selected according to a mode selection signal indicating that a television channel is for the analog video mode or the digital video mode, a large-capacity memory used for the digital video-decoding may also be used as a frame memory for Y/C separation and post-processing, for enhancing picture quality, improving the efficiency of the memory and reducing the cost of a system.

Abstract: The field-display means of a conventional television set are used, to which the odd lines of a VGA image are transmitted during one field and the even lines during the next field, thereby providing for the use of a television set as a computer monitor.

Abstract: A television receiver for processing both analog television signals and digital television signals. Specifically, the television receiver contains a RF/IF front end, an analog-to-digital converter that samples a near baseband signal using a "free running" sample rate, and a combined demodulator that demodulates the digitized analog television signals or the sampled digital television signals. The combined demodulator recovers both pilot and pix carriers as well as provide a passband adaptive equalizer that removes ghosts from analog television signals and intersymbol interference from digital television signals.

Abstract: A universal decoder consisting of modules that may be exchanged with a module of a like type which provides automatic frequency changes and remote system control of the decoder by a host computer. The decoder minimizes signal invasion by providing a data signal frequency change device between a broadcast station and subscriber terminals. Converters modules are classified into fixed function and variable function modules. The fixed function module is a singularly-bodied unit assembled onto a PCB while the variable functions are modularized based on their functions. The connecting circuitry and the data communication protocol between fixed functions and the variable functions is standardized thereby improving the lifetime of the converter. Hacking is solved by allowing the scramble system to be changed. Compatibility problems are eliminated since the modules are made in accordance with internationally uniform or standardized specifications.

Abstract: An audio/video production system facilitates professional quality image manipulation and editing. A program input may be translated into any of a variety of graphics or television formats, including NTSC, PAL, SECAM and HDTV, and stored as data-compressed images, using any of several commercially available methods such as Motion JPEG, MPEG, etc. While being processed, the images may be re-sized to produce a desired aspect ratio or dimensions using conventional techniques such as pixel interpolation, and signals within the video data stream optionally may be utilized to control "pan/scan" operations at a receiving video display unit, in case this unit does not have the same aspect ratio as the source signal. Other information may be utilized to. restrict playback of the program material based on predetermined regional or geographical criteria.

Abstract: A radio receiver for receiving a selected DTV signal that can be a quadrature-amplitude-modulation (QAM) signal or a vestigial sideband (VSB) signal synchrodynes the received signal to baseband and supplies the baseband signal to an adaptive equalizer. The presence of the pilot carrier accompanying a selected VSB DTV signal is detected for automatically switching the radio receiver for operation in a VSB signal reception mode, in which operating mode the adaptive equalizer is conditioned to respond to training signals included in the initial data segment of each data field of the VSB signal. The absence of pilot carrier accompanying a selected QAM DTV signal is detected for automatically switching the radio receiver for operation in a QAM signal reception mode, in which operating mode the adaptive equalizer is conditioned to operate without relying on the training signals included in the VSB signal.

Abstract: In an SIF signal processing circuit, an SIF signal, which is an FM signal having a carrier frequency equal to a frequency difference between a video IF carrier and a sound IF carrier, is first converted to a lower carrier frequency common to SIF signals of any broadcasting system, and is then demodulated. The SIF processing circuit is provided with a PLL circuit for converting an SIF signal down to a lower frequency, so that an output from the PLL circuit is mixed with the SIF signal. The output of the PLL circuit is varied in accordance with a broadcasting system. A plurality of frequencies can be easily obtained from the PLL circuit simply by controlling a frequency division factor of its frequency divider. Thus, resonators can be dispensed with except for one for generating a reference oscillation signal.

Abstract: Radio receivers for receiving DTV signals, in accordance with the Advanced Television Systems Committee (ATSC) standard, or analog TV, in accordance with the National Television Sub-Committee (NTSC) standard, each use a single first detector for both types of signal. This single first detector supplies its output signals to an intermediate-frequency amplifier chain for TV signals and to another intermediate-frequency amplifier chain for analog TV signals. The response of the IF amplifier chain for DTV signals is synchrodyned to baseband, supplied to symbol decoding circuitry, and used by first automatic gain control circuitry to develop AGC for amplifier stages in that IF amplifier chain when DTV signals are received.

Abstract: A television receiver comprising an information extracting circuit for extracting information from a format or content of an input video signal, a video signal processing circuit for processing this video signal by a program or data, a memory for storing the program and data, a CPU for controlling, operating or driving these elements, and a display device for displaying an image. The video signal processing circuit can, under the control of the CPU, decode the signal, correct or set the picture quality such as gradation and sharpness, or adaptively process an on-screen display based on the input video signal. The television receiver is also able to adaptively extend the functions of the television receiver corresponding to various signal formats.

Abstract: In order to play back a plurality of kinds of image data using a single device, a 1394 receiver receives data transmitted via an AV bus according to a format of an IEEE 1394 standard. A separating circuit then determines a format of this data by referring to a prescribed region of a CIP header of this data. When this data is MPEG-PS data, this data is outputted to an MPEG-PS decoder. When this data is MPEG-TS data, this data is outputted to an MPEG-TS decoder. When this data is DVCR SD data, this data is outputted to a DVCR-SD decoder. The MPEG-PS decoder, MPEG-TS decoder and the DVCR-SD decoder then decode the supplied data of respective formats.

Abstract: A display apparatus for displaying a representation of adjustment data for a video display in a multi-frequency video display apparatus includes circuitry for processing video signals having synchronization signals of various frequencies, circuitry for providing input adjustment data, a microcomputer receiving the adjustment data and controlling the video signal processing based on the adjustment data, a display connected with the video signal processing circuitry, on-screen display circuitry for displaying a representation of the adjustment data on the display, and circuitry for controlling the on-screen display so that the representation of the adjustment data is displayed at substantially the same position on the display across different frequency modes of the multi-frequency video display apparatus.

Abstract: A semi-wide view display method and device using the same are provided with a semi-wide view function for arbitrarily converting an aspect ratio of a screen in a television. The method includes the steps of setting a display mode according to a user-selected aspect ratio of a television screen; receiving vertical and horizontal blanking pulses, controlling the width of the blanking pulse according to the display mode setting, and outputting the result; generating a television signal which is displayed on the screen and a blanking signal which is not displayed on the screen by inputting the generated blanking pulse; and displaying the television and the blanking signal to thereby control vertical/horizontal over-scanning and vertically lengthen a blanking period, in order to convert the aspect ratio of the displayed image.

Abstract: To make it possible to receive a modulated signal which is obtained by suppressing a carrier signal such as a high definition TV signal which is digitally demodulated such as QAM (quadrature amplitude modulation), a receiver of the double super-heterodyne system having the first and second mixers 9 and 13 is a basic constitution. A band pass filter having a flatness in pass band and a small deviation of group delay which will prevent the demodulation of a high definition TV signal from degradation is used a first intermediate frequency filter 11. An SAW filter is used as a second intermediate frequency filter 16. The third mixer 28 for converting a second intermediate frequency signal to a third intermediate frequency signal in frequency is installed and the frequency of the third intermediate frequency signal to be converted is set to a value lower than the frequency of the second intermediate frequency signal.