Abstract: An integrated circuit is mounted on a printed board in a state in which a first edge thereof is located to face to a first side of the printed board and a second edge adjacent to the first edge is located to face to a second side adjacent to the first side of the printed board. A power supply terminal provided on the first edge of the integrated circuit, an AGC terminal and an oscillator terminal respectively provided to a third edge are connected to external terminals via conductive patterns extended to the first side on the printed board. An electrode for measurement is provided in the vicinity of the second side on the printed board and an intermediate frequency output terminal provided on a second edge of the integrated circuit is connected to the electrode via a conductive pattern extended from the second edge to the second side on the printed board.

Abstract: An integrated tuner circuit includes a first terminal to which a UHF TV signal is input via a UHF amplifier. The amplifier is switched to an operating state when a UHF TV signal is received. A switching-voltage generation circuit includes a first switching circuit for generating a switching voltage used to switch the operating state of a UHF high-frequency amplifying circuit.

Abstract: A television signal transmitter includes a mixer in which an intermediate-frequency television signal is frequency-converted into a television signal on a channel used for transmission in a predetermined frequency range, a bandpass filter to which the television signal on the channel used for transmission is input and the passband center frequency of which is changed by an applied control voltage, a memory which stores, in the form of digital data, voltages for setting the passband center frequency to equal the frequencies of a plurality of channels in the frequency range, and a D/A converter which converts the digital data into each analog voltage. The analog voltage, at which the passband center frequency equals the frequency of the channel used for transmission, is applied as the control voltage to the bandpass filter.

Abstract: A sharply tuned bandpass RF filter is presented herein. The filter has an input port for receiving television RF signals and passing same to an output port for application to a load. The filter is tuned such that it exhibits the characteristic of passing only RF signals having frequencies within a given frequency channel out of a plurality of channels, all having the same frequency bandwidth while rejecting all other frequencies. The bandwidth of each channel is on the order of W MHz. The filter exhibits an amplitude response within a mandated mask such that when operated in an RF transmitter the amplitude of the response is attenuated uniformly about the center frequency of the given channel within a frequency range of about ±0.5W MHz to a maximum of about ±(0.5W+0.45) MHz and extending to an attenuated level of about ?1 to ?18 dB from the in-band power level.

Abstract: An intermediate-frequency (IF) coupled-circuit for a television tuner is provided, which is connected between an IF amplifying stage and a video-signal-selection filter, and which comprises a parallel circuit having a second capacitor connected in parallel to a series circuit having a resistor for impedance matching, an inductor, and a first capacitor which are connected in series, wherein the series circuit resonates at the frequency component of the selected channel, and the parallel circuit resonates at the frequency component of the channel lower than and adjacent to the selected channel, thereby functioning as a trap for removing the frequency component of the channel lower than and adjacent to the selected channel.

Abstract: In a television tuner, a predetermined bias voltage is applied to the anode of a first switching diode. A power supply voltage is applied to the collector of a switching transistor via a power supply resistor, and the emitter of the switching transistor is grounded. The collector of the switching transistor is connected to an input terminal of a first FET via a first resistor. The first switching diode and the switching transistor are both switched on or off correspondingly to whether a television signal in the UHF band is to be received or a television signal in the VHF band is to be received.

Abstract: Needless signal that causes interference is prevented from entering to eliminate the generation of interfering signal. A television tuner is provided with a band switching circuit to which television signals of a plurality of channels arranged in a predetermined frequency band are supplied, the band switching circuit has a plurality of filters having the cutoff frequency of every one octave frequency in the predetermined frequency band, the cutoff frequency of the plurality of filters is made continuous every one octave in the predetermined frequency band, and the television signal of the channel to be received is sent out through a specified filter having the cutoff frequency within one octave from the frequency of the television signal of the channel to be received.

Abstract: A TV tuner unit uses a frequency-selective element before or after the resonance stage of either a UHF or VHF tuner for separation of UHF signals from VHF signals. Thus, performance is preserved while eliminating the need for circuitry including high and low pass filters and related switches.

Abstract: A tuning system and a tuning method in a broadcast signal receiver, in which a radio frequency (RF) spectrum signal adopting an inverting method is filtered by an asymmetric bandpass filter of a tuner to improve the receiving sensitivity. This tuning system includes a first mixer, a filter and a second mixer. The first mixer mixes a predetermined oscillation frequency with an inverted 8 VSB digital broadcast signal in the idle space between upper and lower normal NTSC broadcast signals of high frequency band received from a transmitter, transfers the upper NTSC broadcast signal to the lower side and the lower NTSC broadcast signal to the upper side, inverts the transferred NTSC broadcast signals, and changes the state of the 8 VSB digital broadcast signal into a normal state. The filter attenuates the inverted upper and lower NTSC broadcast signals output from the first mixer to a predetermined band and amplifies the normal 8 VSB digital broadcast signal into a predetermined band.

Abstract: A multiple conversion tuner comprises a plurality of cascade-connected frequency changers, each of which comprises a mixer and a local oscillator. The tuner also comprises a local oscillator frequency selecting circuit which controls the frequencies of the local oscillators. The frequencies are controlled so that the final mixer converts a desired signal to the final intermediate frequency and so that the frequency band occupied by the desired signal at the output of each mixer is within the passband of the following intermediate frequency part of the tuner.

Abstract: In a manufacturing process in a factory or in a maintenance process in a service center, an initial control program or an updated control program is easily written in a digital TV receiver. The digital TV receiver has an IDE connector to which an external memory apparatus through an IDE cable. A main controller judges whether the external memory apparatus is connected or not with utilizing opening terminals of the IDE connector. When the external memory apparatus is connected, the control program is read out from the external memory apparatus, and written into a control program memory of the digital TV receiver or the existing control program is replaced with the updated control program. When the external memory apparatus is not connected, the existing control program is read out from the control program memory and the digital TV receiver is controlled corresponding to the control program.

Abstract: For optimum videotex data coding, for error-free functioning of so-called descramblers and—not least—for the impression of improved detail resolution on the screen of a television set of displayed pictures, it is known to process the video frequency response by influencing the higher frequency components in the video signal spectrum. According to the invention, adaptation to a video frequency response sought is in each case carried out automatically by means of corresponding shifting of the vision carrier relative to the IF total transmission curve. The respective adaptation for the relevant television channel of the set is effected, in principle, by the addition of a corresponding correction value to the corresponding channel tuning voltage of the tuner.

Abstract: A TV tuner unit is provided with a tuner section for frequency-converting an input TV signal into an intermediate frequency signal, the tuner section having a mixing circuit for frequency conversion, and an oscillation circuit for inputting a local oscillation signal to the mixing circuit; a PLL circuit section for setting a frequency of the local oscillation signal through a tuning voltage by supplying the tuning voltage to the local oscillation circuit; and a video intermediate frequency circuit section for amplifying and detecting the intermediate frequency signal and thereby outputting a video signal and an audio signal, the video intermediate frequency circuit section having at least an intermediate frequency amplification circuit, a video detection circuit, and an audio detection circuit.

Abstract: A television signal receiving tuner that is capable of receiving at least terrestrial television broadcast signals includes a trap circuit for attenuating frequency-modulation broadcast-band signals. The trap circuit attenuates frequency-modulation broadcast-band signals that are in proximity to the desired terrestrial television broadcast signals or are broadcast within a band that are received at one half of the frequency of the desired terrestrial television broadcast signals.

Abstract: An automatic gain control circuit has a tuner for amplifying and IF signal according to an increase or decrease in AGC voltage and outputting it therefrom, first and second detectors for increasing a first control voltage and lowing a second control voltage, respectively, a selector switch for selecting either the first detector or the second detector as a destination to output the IF signal, and a voltage converting circuit for outputting the corresponding AGC voltage therefrom. When the IF signal is inputted to the second detector, the second control voltage is outputted to the tuner, whereas when the IF signal is inputted to the first detector, a voltage corresponding to an increase or decrease in the voltage corresponding to the difference between the maximum voltage outputted from the second detector and the first control voltage is outputted to the tuner.

Abstract: An antenna is directed to optimally receive an advanced television signal. First, the strength of the signal is measured as a function of the azimuth angle of the antenna, and second the flatness of the signal is measured as a function of the azimuth angle of the antenna. The antenna is then rotated to maximize the flatness of the signal while maintaining the strength of the signal above a minimum threshold.

Abstract: A television signal receiving tuner comprises: an integrated circuit including a mixer and an intermediate frequency circuit which frequency convert at least a received television signal RF to an intermediate frequency signal IF; a first intermediate frequency amplifying circuit which is separate from the integrated circuit and has an amplification degree; and an SAW filter which is separate from the integrated circuit and attenuates adjacent bands out of the intermediate frequency band BW of the television signal by a predetermined attenuation amount. The integrated circuit has at least a first terminal and a second terminal and outputs the intermediate frequency signal IF obtained by the frequency conversion by the mixer from the first terminal, and the intermediate frequency signal is serially passed through the intermediate frequency amplifying circuit and the SAW filter and supplied from the second terminal to the intermediate frequency circuit.

Abstract: An automatic fine-tuning control (AFT) voltage generating circuit is provided in which a general-purpose integrated circuit for an intermediate frequency (IF IC) is used, which is capable of easily detecting a low level point in a simple manner without increasing the manufacturing cost. The automatic fine-tuning control voltage generating circuit includes a surface-acoustic-wave (SAW) filter for filtering an intermediate video frequency signal; an IF IC, connected to the SAW filter, for detecting the filtered intermediate video frequency signal and for generating an AFT voltage; and a level shift circuit, connected to the IF IC, for shifting the non-signal-time level of the automatic fine-tuning control voltage generated by the IF IC toward a direction in which the level is lower than an intermediate level between a high level and a low level.

Abstract: The multiple preamplifier circuit for a television tuner has at least one first band with an amplification stage and a second band with an amplification stage. The amplification stage of the first band and the amplification stage of the second band are commonly integrated in a common chip for both bands. The band switching signal and an amplification control signal are applied directly to the common chip.

Abstract: A setting apparatus for setting the tuning voltage of a tunable resonant circuit has an amplification device which amplifies an oscillator tuning voltage, output by a phase locked loop, nonlinearly to produce the tuning voltage. The gain of the amplification device can be set by a digital gain control signal. The signal resolution of the setting apparatus can be controlled in different ways as a function of the gain by using two differently driven digital/analog converters.

Abstract: A remocon locator signal transmitting circuit is provided in an apparatus having a television tuner. When a power for the apparatus is turned on, a micro-computer in the apparatus sets a local oscillation frequency of the television tuner at a predetermined frequency (390 MHz). A 390-MHz local oscillation signal is supplied from the television tuner through an input terminal to the remocon locator transmitting circuit. In the remocon locator transmitting circuit, the local oscillation signal is amplitude-modulated by a code signal applied from the input terminal so that a locator signal is transmitted from a loop antenna.

Abstract: There is provided a UHF/VHF tuner in which complication in structure and increase in manufacturing costs are suppressed and broadcast receiving performance is improved by reducing variation in the reception sensitivity according to frequency when broadcast in the VHF band is received. In a UHF/VHF tuner for receiving both of a broadcast in the UHF band and a broadcast in the VHF band, one mixer and one UHF local oscillator are used for the broadcast in the UHF band, and one mixer, a VHF high-band local oscillator which is switched to be connected when the high band is selected and a VHF low-band local oscillator which is switched to be connected when the low band is selected are used for the broadcast in the VHF band.

Abstract: A television receiver includes a tuner for receiving either analog or digital signals. Separate analog and digital demodulators are selectively coupled to the tuner through an RF switch that is controlled by the signal from a sync detector in the output of the analog demodulator. The selected one of the demodulators develops an AGC signal that is coupled to the tuner through a current mirror. Operating potential for the demodulators is coupled through the RF switch so that the oscillator in the non-selected demodulator is disabled and precluded from interfering with the oscillator in the enabled demodulator.

Abstract: A worldwide television tuning system is configurable to the television standards and channel frequencies of multiple different countries based on a country's ITU long-distance country code. The television tuning system is architected in parallel hardware and software components. The hardware components include tuner circuitry to tune to various television frequencies carrying television video signals and video decoder circuitry coupled to receive a television video signal from the tuner circuitry and to convert the television video signal to digital video data. The software components include a tuner module coupled to adjust the tuner circuitry to a particular television frequency and a video decoder module to decode the digital video data according to a particular video standard. A driver interface layer interfaces the software layer and the hardware circuitry.

Abstract: A television receiver includes an input terminal (12). Through the input terminal is inputted an input signal having a predetermined electric field intensity. That is, a tuner (14) converts the input signal into a video intermediate frequency signal and audio intermediate frequency signal. The video intermediate frequency signal is amplified by a video intermediate frequency amplifier circuit (16). Based on that frequency, a filter (26) outputs a detection signal (Va). An RF-AGC circuit (32) outputs a reference voltage (Vref). An RF-AGC circuit (30) creates a control voltage (Vb) in response to a difference between the detection signal and the reference voltage. The tuner is controlled in gain by this control voltage. The reference voltage is varied by a micro-computer (36) depending upon the control voltage. Accordingly, the control voltage is adjusted to a desired voltage value.

Abstract: A tuner, for example, for a television receiver, includes a UHF and a VHF section and a mixer oscillator stage. It is known that the VHF frequency band has to be split in at least two parts to handle the VHF signals. To that end, the mixer oscillator stage uses two separate VHF oscillators and a detector to switch tuned parts of the VHF section. In this way, the performance of the tuner is improved.

Abstract: Upon installation of a broadcast receiver, for example, a television receiver, the different tuning frequencies/channel numbers are to be stored in a memory of the broadcast receiver. To facilitate the installation, the network provider transmits a list of nominal tuning frequencies, for example, as a teletext page, together with at least one of the broadcast television programs. To further improve installation, also the RF frequency of a so-called subscription channel is also inserted in the list. As the RF frequency of the set-top box may differ from the nominal value in the list, a fine-tuning is performed to modify the stored tuning frequency/frequencies.

Abstract: An AFT circuit achieves automatic fine tuning by use of an AFT voltage obtained by a F/V converter through its F/V conversion of an output from a VCO that is controlled by a PLL circuit to operate in synchronism with a video carrier included in a television signal supplied from outside. The center frequency of the VCO is shifted by adding the AFT voltage to an output signal from the phase comparator of the PLL circuit in order to obtain a wider capture range for automatic fine tuning.

Abstract: A high definition television tuner includes a frequency compensated PI type PIN diode attenuator with the current through the series diode controlled separately from the current through the shunt diodes. A look-up table contains information that correlates the selected RF frequency and the desired AGC level with input data for two D/A converters. A microprocessor controls the D/A digital data, which is based upon information provided by a digital signal processing circuit. In one embodiment of the invention, the look-up table is connected between a D/A converter and a microprocessor and the microprocessor controls the look-up table for supplying the digital data to the D/A converters. In another embodiment, the microprocessor, after receiving the desired AGC level information, first interrogates the look-up table, then supplies the digital data to the D/A converter based.

Abstract: Band characteristics between reception bands or reception channels are uniformed. There is provided a television tuner comprising a first tuning circuit which can be tuned to a television channel frequency in a first frequency band, a first amplification circuit for amplifying an output signal from the first tuning circuit, a second tuning circuit which can be tuned to a television channel frequency in a second frequency band, and a second amplification circuit for amplifying an output signal from the second tuning circuit, wherein, to at least one of the first and second tuning circuits, a damper resistor for decreasing Q of the tuning circuit when the tuning circuit is tuned to a frequency in a low-frequency band including each lowest channel in the first or second frequency band is connected.

Abstract: A video signal level detector is configured to avoid the erroneous recognition of channels adjacent to normal channels as those which are to be stored during performance of an automatic channel detection and storage function. The video signal level detector separates at least two target signals whose levels are to be detected from an input composite video signal; detects signal levels of the target signals; compares each of the detected levels with a reference voltage level; and logic-operates the result to obtain a final detection so that a storage possibility of automatically detected channels is determined.

Abstract: An improved DBS receiver front end architecture having a voltage controlled oscillator for frequency synthesis. The voltage controlled oscillator includes a tank circuit having an adjustable resonance frequency which may be varied over an octave. A tuning oscillator drives the tank circuit and provides a signal having that resonance frequency to a range extender which provides a tuning frequency. When enabled, the range extender doubles the input frequency, and when disabled, simply passes the input frequency through. A feedback path provides a control voltage to the tank circuit to adjust the resonance frequency and thereby cause the tuning frequency to be a multiple of a reference frequency. The range extender extends the tuning frequency range over two octaves without a loss of frequency resolution. Broadly speaking, the present invention contemplates a DBS receiver front end which includes a tuner chip and a demodulator/decoder chip.

Abstract: Tuning circuit in which a local oscillator is constituted by an amplifier which is coupled to a resonant circuit of the variable capacitance and inductance type, the amplifier having a first stage formed by at least one differential pair of bipolar transistors (T1, T2). The amplifier has also a second stage with another differential pair of transistors whose linked emitters are fed by the collector current of one (T2) of the transistors of the first stage. A transistor (T3) of the differential pair of the second stage has its collector coupled to a main load resistor (RL) and its base coupled to the collector of the other transistor (T1) of the first stage, which feeds a supplementary load resistor (Rb). The base of the other transistor (T4) of the differential pair of the second stage may be polarized at a fixed voltage (Vref2) or at a variable voltage, having the appropriate.

Abstract: An automatic fine tuning (AFT) circuit used for processing an image intermediate frequency signal for a video display device. The AFT circuit, which produces an automatic fine tuning signal, by which an image intermediate frequency signal maintains a constant carrier center frequency, includes a phase shift device for performing a phase shift of 90.degree. in the state of the constant carrier center frequency, a control current generating device for generating a control current in response to a variation of a variable resistor value, a resonant frequency variable device for varying a resonant frequency of the resonance circuit, by varying a capacitance to be resonated by the control current, and a phase detecting device for multiplying the image intermediate frequency signal by a phase-shifted image intermediate frequency signal, and for generating the automatic fine tuning signal.

Abstract: An apparatus and a method for extending a pulling range of automatic fine tuning of a television receiver. An initial tuning voltage is applied to a tuner when a channel switching operation is performed or the television receiver is powered on. The tuning voltage to the tuner is controlled by bands as a result of comparison of an automatic fine tuning voltage of a specified channel with a first predetermined reference voltage. If the automatic fine tuning voltage is higher than the first predetermined reference voltage, it is checked whether the automatic fine tuning voltage is within a desired range. The tuning voltage to the tuner is controlled by the bands if the automatic fine tuning voltage is not within the desired range, to maintain the automatic fine tuning voltage within the desired range. Presence of a synchronous signal of the specified channel is checked if the automatic fine tuning voltage is within the desired range.

Abstract: A signal selecting circuit including a first, second and third inductors coupled in series in the order named, a fourth inductor coupled between an output terminal of the third inductor and a reference potential, and varactor diodes responsive to a tuning signal for varying the frequency response of the signal selecting circuit. The signal selecting circuit includes bandswitching circuitry for changing the configuration of the signal selecting circuit in response to the frequency band of the selected signal.

Abstract: A double conversion type television tuning system for a digital television signal includes a synthesizer for developing a tuning voltage for the upconverter. The synthesizer provides bandswitching for dividing the tuning range into four portions and includes a separate local oscillator for each portion. Each local oscillator is enabled by a transistor that is switched by a bandswitch voltage. The output of each oscillator is applied through respective bandswitched buffer amplifiers to an arrangement of three 3 dB hybrid couplers to convey the appropriate local oscillator signal to the upconverter mixer. The system minimizes phase noise and jitter which is essential when operating with digital signals.

Abstract: Tuning apparatus for a television system, comprising a rotary encoder having a slidable and rotatable channel changing mechanism, the rotary encoder outputting a plurality of signals with a phase difference with respect to one another, corresponding to a channel change in accordance with the rotation of the channel changing mechanism, a microcomputer for calculating a channel number to be changed in accordance with the output signals from the rotary encoder and outputting channel receive data corresponding to the calculated channel number, and a tuner for receiving a television broadcasting signal of a channel corresponding to the channel receive data from the microcomputer.

Abstract: A television receiver includes a long loop frequency and phase locked loop (FPLL) in which the tuner voltage is controlled by the output voltage of the FPLL. A SAW bandpass filter couples the IF signal from the tuner to a synchronous demodulator and to the FPLL. An oscillator includes a SAW resonator that is formed on the same substrate as the SAW bandpass filter for supplying a reference signal to the FPLL and to the synchronous demodulator. The common substrate assures tracking between the IF SAW bandpass filter and the oscillator SAW resonator with temperature changes and processing variations.