Abstract: A STB 1 of this CATV system includes a diplexer 11, a signal level adjusting unit 30, a splitter 12, a tuner 2, a demodulating unit 3, a memory 17, and a CPU 19. The CPU 19 finds a correct reception level of a downstream signal by arithmetically operating a level correction value which is found based on a detected level adjustment state (state of switches) of the signal level adjusting unit 30 and a reception level after AGC which is found from signal intensity outputted from the demodulating unit 3, and notifies the found reception level to a CATV center station 40 by means of an upstream signal.

Abstract: There is provided a highly reliable transmission/reception integrated radio-frequency apparatus which can achieve a high communication quality in a cable modem. A reception RF signal is input to a reception system block via an input/output terminal, converted to an intermediate-frequency signal, and output from a terminal. An output terminal of a transmission processing section of a transmission system block is connected to the input/output terminal via an overvoltage protection circuit, a high-pass filter functioning as a countermeasure to overvoltage, and a low-pass filter for suppressing harmonics produced from the high-pass filter.

Abstract: According to one embodiment, an information processing apparatus includes a metal casing mounted on a base plate, a circuit board housed in the casing, and a connector to which a signal cable is detachably connected. The casing has a cover surface that covers the circuit board from the side opposite to the base plate and a connector mount section that is stepped from the cover surface toward the base plate. The connector is secured onto the bottom of the connector mount section.

Abstract: A STB 1 of this CATV system includes a diplexer 11, a signal level adjusting unit 30, a splitter 12, a tuner 2, a demodulating unit 3, a memory 17, and a CPU 19. The CPU 19 finds a correct reception level of a downstream signal by arithmetically operating a level correction value which is found based on a detected level adjustment state (state of switches) of the signal level adjusting unit 30 and a reception level after AGC which is found from signal intensity outputted from the demodulating unit 3, and notifies the found reception level to a CATV center station 40 by means of an upstream signal.

Abstract: There is discolsed a cable modem device capable of reducing unnecessary signals inputted into a circuit substrate which processes signals and signal terminals from the outside and unnecessary radiation generated by the circuit substrate, the device having a hexahedral shield case which shields a circuit substrate, and a plurality of terminals for use in input/output of the signals with respect to the circuit substrate. Each of the terminals has a noise filter function, and is fixed to the shield case.

Abstract: According to one embodiment, a cable modem module includes a first RF terminal connected to a CATV center station via a cable and a second RF terminal connected to an external tuner module. The second RF terminal is provided to the distributor-embedded cable modem module in such a manner that the height of the second RF terminal is identical to that of an RF input terminal of the external tuner module when the distributor-embedded cable modem module and the external tuner module are mounted to a circuit substrate, and has a structure to be directly connected to the RF input terminal.

Abstract: There is disclosed a cable modem device capable of reducing unnecessary signals inputted into a circuit substrate which processes signals and signal terminals from the outside and unnecessary radiation generated by the circuit substrate, the device having a hexahedral shield case which shields a circuit substrate, and a plurality of terminals for use in input/output of the signals with respect to the circuit substrate. Each of the terminals has a noise filter function, and is fixed to the shield case.

Abstract: There is discolsed a cable modem device capable of reducing unnecessary signals inputted into a circuit substrate which processes signals and signal terminals from the outside and unnecessary radiation generated by the circuit substrate, the device having a hexahedral shield case which shields a circuit substrate, and a plurality of terminals for use in input/output of the signals with respect to the circuit substrate. Each of the terminals has a noise filter function, and is fixed to the shield case.

Abstract: There is provided a highly reliable transmission/reception integrated radio-frequency apparatus which can achieve a high communication quality in a cable modem. A reception RF signal is input to a reception system block via an input/output terminal, converted to an intermediate-frequency signal, and output from a terminal. An output terminal of a transmission processing section of a transmission system block is connected to the input/output terminal via an overvoltage protection circuit, a high-pass filter functioning as a countermeasure to overvoltage, and a low-pass filter for suppressing harmonics produced from the high-pass filter.

Abstract: There is provided a highly reliable transmission/reception integrated radio-frequency apparatus which can achieve a high communication quality in a cable modem. A reception RF signal is input to a reception system block via an input/output terminal, converted to an intermediate-frequency signal, and output from a terminal. An output terminal of a transmission processing section of a transmission system block is connected to the input/output terminal via an overvoltage protection circuit, a high-pass filter functioning as a countermeasure to overvoltage, and a low-pass filter for suppressing harmonics produced from the high-pass filter.

Abstract: A cable modem module device includes a coaxial connector to transmit and receive high-frequency signals, a circuit board to which the coaxial connector is attached to protrude from its periphery in a direction parallel to its surface, and a first shield case formed in its portion corresponding to the coaxial connector with a cutout portion to avoid the coaxial connector so as to allow the circuit board to be housed from a direction perpendicular to the surface of the circuit board.

Abstract: When a CATV signal supplied from a CATV center station is distributed to be lead out to a television tuner, an RF connector is provided on a circuit board of an analog signal processing section, and is configured to lead out the CATV signal by means of this RF connector. In this manner, a distribution output does not pass through a circuit board of a digital signal processing section. Therefore, a high quality signal can be distributed and outputted without being adversely affected by a digital signal.

Abstract: A cable modem module including a first shield case configured to house a tuner unit, a first terminal used to input analog signals to the tuner unit and output the analog signals therefrom, a circuit board having the first terminal connected to it and configured to have a digital signal processing unit to digital process signals to be input to or output from the tuner unit, a second shield case configured to house the circuit board and the first shield case, and a plurality of second terminals each terminal having its one connected to the circuit board and its other end passed through the second shield case to project to outside and configured to input or output digital signals to or from the digital signal processing unit, each of the second terminals being comprised of a through capacitor.

Abstract: A cable modem module unit includes a tuner section configured to have an analog signal processing section for transmitting/receiving a high frequency signal, a digital signal processing section configured to perform digital processing on the signal input to and output from the tuner section, a shield case configured to hold the digital signal processing section and tuner section therein, and a terminal group configured to be connected at one end to the digital signal processing section and, at the other end, inserted into the shield case and extending outwardly to allow a digital signal to be input to, and output from, the digital signal processing section, the terminal group including a first terminal as part of the terminal group to allow a setting or checking to or for the digital signal processing section to be effected from outside the shield case.

Abstract: A cable modem module unit includes a tuner section configured with an analog signal processing unit for transmitting/receiving a high frequency signal via a coaxial connector, a first shield case configured to hold the tuner section therein with the coaxial connector externally exposed, a circuit board having the first shield case thereon and configured to provide a digital signal processing section including a memory for allowing the inputting and outputting of digital data, the digital signal processing section performing digital processing on a signal input to and output from the tuner section, and a second shield case configured to hold the circuit board and first shield case therein with the coaxial connector externally exposed, on the same plane of the circuit board, the coaxial connector and memory being located in an opposed relation with the first shield case in between.

Abstract: A cable modem module device comprising a coaxial connector to transmit and receive high-frequency signals, a circuit board to which the coaxial connector is attached to protrude from its periphery in a direction parallel to its surface, and a first shield case formed in its portion corresponding to the coaxial connector with a cutout portion to avoid the coaxial connector so as to allow the circuit board to be housed from a direction perpendicular to the surface of the circuit board.

Abstract: A cable modem module comprising a first shield case configured to house a tuner unit, a first terminal used to input analog signals to the tuner unit and output the analog signals therefrom, a circuit board having the first terminal connected to it and configured to have a digital signal processing unit to digital process signals to be input to or output from the tuner unit, a second shield case configured to house the circuit board and the first shield case, and a plurality of second terminals each terminal having its one connected to the circuit board and its other end passed through the second shield case to project to outside and configured to input or output digital signals to or from the digital signal processing unit, each of the second terminals being comprised of a through capacitor.

Abstract: There is disclosed a cable modem device capable of reducing unnecessary signals inputted into a circuit substrate which processes signals and signal terminals from the outside and unnecessary radiation generated by the circuit substrate, the device having a hexahedral shield case which shields a circuit substrate, and a plurality of terminals for use in input/output of the signals with respect to the circuit substrate. Each of the terminals has a noise filter function, and is fixed to the shield case.

Abstract: A reception circuit is designed to be free from the influence of noise from a Zener diode. This circuit may have a selection unit which selects a desired broadcast signal in accordance with control signal Vt, an amplifier unit which amplifies the broadcast signal, a booster circuit which increases power supply potential B+ to generate an increased potential, a control unit which is responsive to the increased potential, and generates a control signal used to designate a desired broadcast signal so as to supply the control signal to the selection unit, and Zener diode ZD which has Zener voltage Vz larger than maximum potential Vtmax of the control signal. This diode ZD suppresses or limits the increased potential to be equal to or lower than the Zener voltage. Since the Zener diode does not bring about any breakdown operation in a steady state, a noise-free reception can be assured.

Abstract: There is provided a highly reliable transmission/reception integrated radio-frequency apparatus which can achieve a high communication quality in a cable modem. A reception RF signal is input to a reception system block via an input/output terminal, converted to an intermediate-frequency signal, and output from a terminal. An output terminal of a transmission processing section of a transmission system block is connected to the input/output terminal via an overvoltage protection circuit, a high-pass filter functioning as a countermeasure to overvoltage, and a low-pass filter for suppressing harmonics produced from the high-pass filter.