The present invention relates to a broadcast reception device. A broadcast reception device according to one embodiment of the present invention comprises: an impedance matching circuit for adjusting an input impedance value of the broadcast reception device; and a control unit, wherein the control unit can control the impedance matching circuit so as to adjust the input impedance value to a predetermined reference impedance value when the mode of the broadcast reception device is a mode for receiving a broadcast signal through a cable, and control the impedance matching circuit so as to adjust the input impedance value to be less than the predetermined reference impedance value when the mode of the broadcast reception device is not the mode for receiving a broadcast signal through a cable. Therefore, since a broadcast signal can be appropriately amplified while a criterion related to a reflection loss is satisfied, network management costs of a network provider can be reduced and a broadcast image of better quality can be provided to a user. Other various embodiments are possible.

The present invention relates to a broadcast reception device. A broadcast reception device according to one embodiment of the present invention comprises: an impedance matching circuit for adjusting an input impedance value of the broadcast reception device; and a control unit, wherein the control unit can control the impedance matching circuit so as to adjust the input impedance value to a predetermined reference impedance value when the mode of the broadcast reception device is a mode for receiving a broadcast signal through a cable, and control the impedance matching circuit so as to adjust the input impedance value to be less than the predetermined reference impedance value when the mode of the broadcast reception device is not the mode for receiving a broadcast signal through a cable. Therefore, since a broadcast signal can be appropriately amplified while a criterion related to a reflection loss is satisfied, network management costs of a network provider can be reduced and a broadcast image of better quality can be provided to a user. Other various embodiments are possible.

An information terminal with low power consumption is provided. The information terminal includes a liquid crystal element, a light-emitting element, a first transistor, and a touch sensor. The touch sensor includes a photodiode, a second transistor, and a third transistor. The first transistor has a function of controlling a current flowing through the light-emitting element. The photodiode is electrically connected to a gate of the third transistor through the second transistor. A gate of the first transistor is electrically connected to the gate of the third transistor through at least one transistor.

An information terminal with low power consumption is provided. The information terminal includes a liquid crystal element, a light-emitting element, a first transistor, and a touch sensor. The touch sensor includes a photodiode, a second transistor, and a third transistor. The first transistor has a function of controlling a current flowing through the light-emitting element. The photodiode is electrically connected to a gate of the third transistor through the second transistor. A gate of the first transistor is electrically connected to the gate of the third transistor through at least one transistor.

Low-noise block downconverter (LNB) of a satellite dish receives a request from a satellite broadcast signal receiver to transmit a signal for a channel to the receiver. If the channel requested by the receiver is different from a channel requested by another satellite broadcast signal receiver, the LNB in response provides a signal for the channel requested by the receiver at a frequency that is allocated to the receiver. If the channel requested by the receiver is the same as a channel requested by another satellite broadcast signal receiver, the LNB provides an instruction to the requesting receiver for the receiver to retune to the frequency used for the other satellite broadcast signal receiver. The requesting receiver can then receive the signal for said channel which is being provided by the LNB at the frequency used for the other satellite broadcast signal receiver.

Low-noise block downconverter (LNB) of a satellite dish receives a request from a satellite broadcast signal receiver to transmit a signal for a channel to the receiver. If the channel requested by the receiver is different from a channel requested by another satellite broadcast signal receiver, the LNB in response provides a signal for the channel requested by the receiver at a frequency that is allocated to the receiver. If the channel requested by the receiver is the same as a channel requested by another satellite broadcast signal receiver, the LNB provides an instruction to the requesting receiver for the receiver to retune to the frequency used for the other satellite broadcast signal receiver. The requesting receiver can then receive the signal for said channel which is being provided by the LNB at the frequency used for the other satellite broadcast signal receiver.

The present invention provides a digital video broadcasting-terrestrial (DVB-T) system and modulation method thereof. The system comprises a transmission module and a receiving module. The transmission module modulates a video signal to a DVB-T signal. The receiving module receives the DVB-T signal via a transmission line and demodulates the DVB-T signal to the video signal, and at the same time, monitoring the signal-to-noise ratio (SNR) or bit error rate (BER), and quantizes them to a reference data. The receiving module transmits the reference data to the transmission module through the same transmission line. The system can determine a control parameter according to the reference data to set the modulation parameter of the DVB-T signal.

The present invention provides a digital video broadcasting-terrestrial (DVB-T) system and modulation method thereof. The system comprises a transmission module and a receiving module. The transmission module modulates a video signal to a DVB-T signal. The receiving module receives the DVB-T signal via a transmission line and demodulates the DVB-T signal to the video signal, and at the same time, monitoring the signal-to-noise ratio (SNR) or bit error rate (BER), and quantizes them to a reference data. The receiving module transmits the reference data to the transmission module through the same transmission line. The system can determine a control parameter according to the reference data to set the modulation parameter of the DVB-T signal.

Disclosed is a transmitter that includes a demodulation circuit and a transmitting-side back-end processing circuit. When a TLV packet superimposed on a broadcast wave and transmitted with a variable data length is to be converted to split TLV packets with a fixed data length, the demodulation circuit sets a speed for switching between L and H levels of a clock signal in such a manner that the speed for first data including a packet header to be embedded in a header section of the split TLV packets is twice the speed for data subsequent to the first data. The transmitting-side back-end processing circuit QAM-modulates a signal demodulated by the demodulation circuit for cable broadcasting purposes.

Disclosed is a transmitter that includes a demodulation circuit and a transmitting-side back-end processing circuit. When a TLV packet superimposed on a broadcast wave and transmitted with a variable data length is to be converted to split TLV packets with a fixed data length, the demodulation circuit sets a speed for switching between L and H levels of a clock signal in such a manner that the speed for first data including a packet header to be embedded in a header section of the split TLV packets is twice the speed for data subsequent to the first data. The transmitting-side back-end processing circuit QAM-modulates a signal demodulated by the demodulation circuit for cable broadcasting purposes.