JP5175801B2 - Information processing apparatus and signal level control method - Google Patents

Description

  The present invention relates to an information processing apparatus having a function of receiving a television broadcast signal and a signal level control method applied to the apparatus.

  In recent years, personal computers having the same AV function as audio / video (AV) devices such as DVD (Digital Versatile Disc) players, video recorders, and TV apparatuses have been developed.

  Such a personal computer has a tuner for receiving a television broadcast signal, and can perform viewing and recording of broadcast program data. In recent years, in an information processing apparatus such as a personal computer, two tuners have been required to be installed in order to realize a function of recording a broadcast program while listening to a broadcast program. However, personal computers are smaller than TV devices and already have many devices for computing. For this reason, when two tuners are mounted on a personal computer, a device for reducing cost and mounting space is required.

  Patent Literature 1 discloses a television receiver including two tuners. In this television receiver, the two tuners are connected to the antenna terminal via a distributor. Also, an amplifier for amplifying each of the signals distributed to the two tuners is provided in the distributor.

  However, in such a configuration in which a distributor composed of parts independent of the two tuners is provided, an increase in the number of parts increases the cost and occupies a lot of mounting space.

  In Patent Document 2, an independent distributor is not provided, but a broadcast signal input to the first tuner is distributed to the second tuner via a distribution circuit and an amplifier provided in the first tuner. The structure to perform is disclosed. With this configuration, the number of necessary parts can be reduced.

JP 2008-118415 A JP 2005-130240 A

  However, when two tuners are connected in cascade as in Patent Document 2, television broadcasting input to the second tuner due to signal loss due to wiring between the first tuner and the second tuner. The signal level of the signal is lower than the signal level of the television broadcast signal input to the first tuner. For this reason, in an environment where the reception level of the broadcast signal is relatively low, the signal level of the broadcast signal input to the second tuner becomes lower than the receivable level, and the first tuner receives the broadcast signal normally. However, there is a possibility that the second tuner cannot receive the broadcast signal normally.

  In this case, for example, in a use case in which the second tuner is used to record the second channel broadcast program data while the first tuner is used to view the first channel broadcast program data, the first channel broadcast is performed. Although the program data can be normally viewed, the broadcast program data of the second channel cannot be normally recorded. In an on-air reception environment, signal levels may differ between channels. Therefore, a situation may occur in which channels that can be normally received are different between the first tuner and the second tuner.

  In Patent Document 2, the level of the broadcast signal distributed to the second tuner is always amplified by an amplifier at the subsequent stage of the distribution circuit in the first tuner.

  However, when the configuration of simply amplifying the signal level input to the second tuner in this way is employed, for example, in a multi-channel high-level environment such as a cable TV, the signal is input to the second tuner. The signal level becomes too strong, which may increase the noise component and reveal signal interference between channels.

  The present invention has been made in consideration of the above circumstances, and an information processing apparatus and signal level control capable of suppressing the occurrence of a problem that one of two cascaded tuners cannot normally receive a broadcast signal. It aims to provide a method.

In order to solve the above-described problem, an information processing apparatus according to claim 1 includes a first tuner that receives a television broadcast signal input from a broadcast signal input terminal, and a distribution provided in the first tuner. a second tuner for receiving a television broadcast signal distributed from the first tuner by the circuit, and the signal level detecting means for detecting the signal level of the television broadcast signal input to the first tuner, the A setting screen for allowing the user to designate one of the first mode, the second mode, and the third mode as a mode for the boost function for increasing the signal level of the television broadcast signal input to the second tuner. a setting screen means for displaying on the display, when the first mode is designated by operating the input device, the detected signal les Depending on the Le, set to one of the amplifiers turned on or off to increase the signal level of the television broadcast signal to be distributed to the second tuner, the second mode by the operation of the input device Or when any one of the third modes is designated, control means for setting the amplifier to either the on state or the off state regardless of the detection result of the signal level by the signal level detecting means. It is characterized by.

  According to the present invention, it is possible to suppress the occurrence of a problem that one of two cascaded tuners cannot normally receive a broadcast signal.

The perspective view which shows the example of the external appearance of the information processing apparatus which concerns on one Embodiment of this invention. 2 is an exemplary block diagram showing an example of the system configuration of the information processing apparatus according to the embodiment. FIG. FIG. 3 is an exemplary block diagram illustrating a configuration example of each of two tuners provided in the information processing apparatus according to the embodiment. FIG. 5 is a diagram showing an example of a tuner setting screen used in the information processing apparatus according to the embodiment. 5 is a flowchart for explaining a booster control process executed by the information processing apparatus according to the embodiment when the auto mode is selected by an operation on the tuner setting screen of FIG. 4. 5 is a flowchart for explaining a booster control process executed by the information processing apparatus according to the embodiment when an off mode or an on mode is selected by an operation on the tuner setting screen of FIG. 4. The figure which shows the example of the relationship between the AGC level of each channel detected by auto mode, and the ON / OFF setting of an amplifier. The figure which shows the other example of the relationship between the AGC level of each channel detected by auto mode, and ON / OFF setting of an amplifier. The figure which shows the further another example of the relationship between the AGC level of each channel detected by auto mode, and the ON / OFF setting of an amplifier. The figure which shows the example of the gain flag table used with the information processing apparatus which concerns on the same embodiment. 9 is a flowchart showing an example of another procedure of booster control processing executed by the information processing apparatus according to the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the configuration of an information processing apparatus according to an embodiment of the present invention will be described with reference to FIG. This information processing apparatus is realized by, for example, a notebook portable personal computer 10. The computer 10 has a TV function for viewing and recording broadcast program data broadcast by a television broadcast signal. This TV function also includes a reserved recording function for recording broadcast program data in accordance with a recording reservation set by the user. The control of the TV function is realized by, for example, a TV application program installed in the computer 10 in advance. The computer 10 is provided with two tuners that respectively receive television broadcast signals such as terrestrial digital broadcast signals. The TV application program selectively uses two tuners and controls viewing or recording of broadcast program data received by these tuners. In addition, this TV application program has a video function for reproducing recorded broadcast program data and other video data, a function for displaying electronic program information (EPG) for each of a plurality of channels broadcast by a television broadcast signal, and the like. Also have.

  FIG. 1 is a perspective view of the computer 10 with the display unit opened. The computer 10 includes a computer main body 11 and a display unit 12. The display unit 12 incorporates a display device including a TFT-LCD (Thin Film Transistor Liquid Crystal Display) 17. The display unit 12 is attached to the computer main body 11 so as to be rotatable between an open position and a closed position.

  The computer main body 11 has a thin box-shaped casing. On the upper surface of the computer main body 11, a keyboard 13, a power button 14 for turning on / off the computer 10, an input operation panel 15, and a touch pad (mouse) 16 are provided. Etc. are arranged. The input operation panel 15 can include various operation buttons such as a TV button, a recording button, and a channel switching button. The TV button is a button that requests execution of the TV function. When the TV button is pressed, a TV application program is activated, and a TV function such as viewing processing for receiving and viewing broadcast program data of a designated channel is automatically executed. The record button is an operation button for instructing recording of broadcast program data being viewed. The channel switching button is an operation button for instructing switching of a viewing target channel.

  The computer main body 11 is provided with a broadcast signal input terminal 18. The broadcast signal input terminal 18 is connected to an antenna or a CATV network via a cable (antenna cable). On the front surface of the computer main body 11, a remote control unit interface unit 20 is provided for executing communication with an external remote control unit that remotely controls the TV function of the computer 10. The remote control unit interface unit 20 includes, for example, an infrared signal receiving unit.

  Next, the system configuration of the computer 10 will be described with reference to FIG.

  As shown in FIG. 2, the computer 10 includes a CPU 111, a north bridge 112, a main memory 113, a graphics controller 114, a south bridge 119, a BIOS-ROM 115, a sound controller 116, a speaker 117, and a hard disk drive (HDD) 121. An optical disk drive (ODD) 122, two tuners 123A and 123B, an embedded controller / keyboard controller IC (EC / KBC) 124, a power supply circuit 125, and the like.

  The CPU 111 is a processor provided for controlling the operation of the computer 10, and stores various application programs such as the operating system 102 and the TV application program 101 that are loaded from the hard disk drive (HDD) 121 to the main memory 113. Run. The TV application program 101 is a program for controlling viewing and recording of broadcast program data. The TV application program 101 controls the tuners 123A and 123B to obtain video data included in the broadcast program data (TV broadcast programs) received by the tuners 123A and 123B. A viewing process to be displayed on the display device and a recording process (including reserved recording) to store the received broadcast program data in the recording medium are executed. The TV application program 101 is configured to operate on the operating system 102. Further, the CPU 111 also executes a basic input output system (BIOS) stored in the BIOS-ROM 115. The BIOS is a program for hardware control.

  The north bridge 112 is a bridge device that connects the local bus of the CPU 111 and the south bridge 119. The north bridge 112 also includes a memory controller that controls access to the main memory 113. The north bridge 112 also has a function of executing communication with the graphics controller 114.

  The graphics controller 114 is a display controller that controls the LCD 17 used as a display monitor of the computer 10. The graphics controller 114 displays the image data written in the video memory (VRAM) 114 A by the OS 102 or the TV application program 101 on the LCD 17. The south bridge 119 controls each device on an LPC (Low Pin Count) bus. The south bridge 119 incorporates a USB controller for controlling a USB (Universal Serial Bus) device and an IDE (Integrated Drive Electronics) controller for controlling the HDD 121 and the ODD 122.

  The two tuners 123A and 123B are TV tuners that receive the same type of television broadcast signal. For example, the first tuner 123A is composed of a digital TV tuner that receives terrestrial digital broadcast signals, and similarly, the second tuner 123B is composed of a digital TV tuner that receives terrestrial digital broadcast signals. ing. A stream of broadcast program data broadcast by a terrestrial digital broadcast signal is encrypted (scrambled). Each of the tuners 123A and 123B has a copyright protection function, and decrypts the received broadcast program data by using key information stored in an IC card (not shown) called a B-CAS card. The broadcast program data thus transmitted can be transmitted to the south bridge 119 via a serial bus such as USB.

  In the present embodiment, the first tuner 123A and the second tuner 123B are cascade-connected (cascade connection). That is, the first tuner 123A is directly connected to the broadcast signal input terminal 18, but the second tuner 123B is connected to the first tuner 123A. The first tuner 123A receives the television broadcast signal input from the television broadcast signal input terminal 18. On the other hand, the second tuner 123B receives a television broadcast signal distributed from the first tuner 123A by a distribution circuit provided in the first tuner 123A. Thus, by cascading the two tuners 123A and 123B, it is not necessary to provide a distributor for distributing the broadcast signal input from the broadcast signal input terminal 18 to the two tuners 123A and 123B. As a result, the mounting space can be effectively used and the cost can be reduced.

  The first tuner 123A includes an amplifier (AMP) 200 for increasing the signal level of the television broadcast signal distributed from the first tuner 123A to the second tuner 123B by the distribution circuit in the first tuner 123A. Is provided. The amplifier (AMP) 200 functions as a booster for the second tuner 123B. In the present embodiment, the amplifier (AMP) 200 can be switched to an on state or an off state under the control of the TV application program 101. That is, the TV application program 101 detects the signal level of the television broadcast signal input to the first tuner 123A, and the amplifier (AMP) 200 is turned on or off depending on the detected signal level. Set it.

  Since the first tuner 123A and the second tuner 123B are cascade-connected, the signal level of the television broadcast signal input to the second tuner 123B is the television broadcast input to the first tuner 123A. It is lower than the signal level of the signal. For this reason, the amplifier (AMP) 200 must be turned on. However, when the amplifier (AMP) 200 is turned on in a multi-channel / high-level environment such as cable TV, interference in the multi-wave environment (signal interference between channels). The amplifier (AMP) 200 must be turned off. However, it is not preferable from the viewpoint of operability to make the user aware of differences in reception environments such as an on-air reception environment and a CATV environment. Therefore, in this embodiment, there is a booster setting function for the second tuner that automatically switches on / off the amplifier (AMP) 200 in accordance with the signal level of the television broadcast signal input to the first tuner 123A. Is provided. With the booster setting function for the second tuner, the television broadcast signal input to the second tuner 123B can be input to the second tuner 123B according to the current reception environment without the user being aware of the reception environment such as the on-air reception environment or the CATV environment. The signal level can be adjusted automatically.

  2 shows an example in which the tuners 123A and 123B are connected to the USB, respectively. For example, a function for executing communication with the USB is provided only in the first tuner 123A that is the master, and the slave is the slave. A certain second tuner unit 123B may execute communication with the USB via the first tuner unit 123A.

  The EC / KBC 124 is a one-chip microcomputer in which an embedded controller for power management and a keyboard controller for controlling the keyboard (KB) 13 and the touch pad 16 are integrated. The EC / KBC 124 has a function of powering on / off the computer 10 in accordance with the operation of the power button 14 by the user in cooperation with the power supply circuit 125. The power supply circuit 125 generates an operation power supply to be supplied to each component of the computer 10 from a battery 126 built in the computer 10 or an external power supply supplied from the outside via the AC adapter 127. The EC / KBC 124 is also connected to the remote control unit interface unit 20.

  The TV application program 101 is controlled not only by the operation of the input device such as the keyboard (KB) 13, the input operation panel 15, and the touch pad (mouse) 16 by the user, but also by the operation of an external remote control unit. Can do.

Next, a configuration example of the tuners 123A and 123B will be described with reference to FIG.
In addition to the above-described amplifier (AMP) 200, the tuner 123A includes a distribution circuit 201, a channel selection unit 202, an AGC amplifier 201, a demodulation unit 204, and a controller 205. The television broadcast signal (RF signal) input to the broadcast signal input terminal 18 is divided into two by the distribution circuit 201, one broadcast signal is sent to the channel selection unit 202, and the other broadcast signal is passed through an amplifier (AMP) 200. To the tuner 123B. Under the control of the controller 205, the channel selection unit 202 extracts only a signal belonging to the frequency band of the reception target channel from a television broadcast signal (hereinafter simply referred to as a broadcast signal), so that a plurality of channels in the broadcast signal are extracted. To select the signal corresponding to the reception target channel. The channel selection unit 202 includes a frequency conversion circuit called a mixer, and the channel selection unit 202 outputs an intermediate frequency signal corresponding to the reception target channel. The intermediate frequency signal is sent to the AGC amplifier 303.

  The AGC amplifier 203 is an amplifier with an automatic gain control (AGC) function, and amplifies an intermediate frequency signal to be input to the demodulation unit 204. The gain (amplification factor) of the AGC amplifier 203 is automatically adjusted according to the signal level so that the signal level of the intermediate frequency signal falls within a certain range. When the signal level is low, the gain of the AGC amplifier 203 is increased, and when the signal level is high, the gain of the AGC amplifier 203 is decreased. The gain of the AGC amplifier 203 can be controlled by the controller 205 based on, for example, the signal level of the intermediate frequency signal corresponding to the channel selected by the channel selection unit 202 or the output result of the demodulation unit 204. The intermediate frequency signal whose level has been adjusted by the AGC amplifier 203 is demodulated by the demodulation unit 205, and the demodulation result is sent to the controller 205.

  As described above, the amplifier (AMP) 200 is a booster for increasing the signal level of the broadcast signal supplied from the first tuner 123A to the second tuner 123B. The amplifier (AMP) 200 is set to either an on state or an off state by a controller 205.

  Each of the first tuner 123A and the second tuner 123B can be realized by the same tuner module. In this case, similarly to the first tuner 123A, the second tuner 123B includes a distribution circuit 301, a channel selection unit 302, an AGC amplifier 301, a demodulation unit 304, a controller 305, and an amplifier 306. The distribution circuit 301, the channel selection unit 302, the AGC amplifier 301, the demodulation unit 304, the controller 305, and the amplifier 306 are the distribution circuit 201, the channel selection unit 202, the AGC amplifier 201, the demodulation unit 204, the controller 205, and the amplifier 200 of the tuner 123. And have the same functions. In the second tuner 123B, the broadcast signal (RF signal) from the first tuner 123A is divided into two by the distribution circuit 301, and one broadcast signal (RF signal) is sent to the channel selection unit 302, and the other broadcast signal. (RF signal) is sent to the amplifier 306. In a configuration in which a third tuner is further cascaded after the second tuner 123B, the amplifier 306 can be used as a booster for amplifying a broadcast signal distributed to the third tuner. In the present embodiment, since the third tuner is not used, the amplifier 306 may be always set to the off state.

  FIG. 4 shows an example of a booster setting screen displayed on the display by the TV application program 101. This booster setting screen is a GUI for setting a booster setting function for the second tuner (terrestrial D2 tuner). This booster setting screen is used for allowing the user to specify on or off of the boost function for increasing the signal level of the broadcast signal input to the second tuner 123B.

  The booster setting function for the second tuner has three modes of “auto”, “on”, and “off”. “Auto” is a mode in which on / off of the amplifier (AMP) 200 is automatically determined according to the signal level of the broadcast signal input to the tuner 123A.

  In the “auto” mode, the detection of the signal level of the broadcast signal and the on / off setting of the amplifier (AMP) 200 are executed at the time of channel scanning, for example. The channel scan is a process for detecting a plurality of effective channels existing in the input broadcast signal by referring to the demodulation result while sequentially changing the reception target channel (frequency band) by the channel selection unit 202. This channel scan is executed for the tuner 123A. For example, if each of tuners 123A and 123B supports both on-air reception of the UHF band and CATV pass-through reception of the VHF band, channel scanning is performed for each of the UHF band and the VHF band. The result of the channel scan executed using the tuner 123A is used not only for station selection control by the tuner 123A but also for station selection control by the tuner 123B. At the time of channel scanning, an effective channel used for TV broadcasting, that is, a channel that can receive a broadcast signal that can be viewed, is also detected. The default mode of the booster setting function for the second tuner is set to “auto” mode, for example.

  The “on” mode and the “off” mode are modes for forcibly turning on or off the amplifier 200 by manual operation regardless of the detection result of the signal level. By using these “on” and “off” modes, the input level of the broadcast signal to the tuner 123B can be optimized even when the current reception environment is different from the reception environment during channel scanning. Can do. Further, when the “on” mode or “off” mode is designated by the user, the amplifier 200 can be forcibly turned on or off immediately without performing a channel scan. Therefore, immediately after the change from the on-air reception environment to the CATV reception environment or immediately after the change from the CATV reception environment to the on-air reception environment, each of the two tuners can normally receive the broadcast signal.

  Next, the procedure of signal level control processing executed by the TV application program 101 in the “auto” mode will be described with reference to the flowchart of FIG. This signal level control process is executed during channel scanning as described above.

  First, as an initial setting process, the TV application program 101 sets a variable CH indicating a reception target channel to a value indicating the first frequency band in the scan target frequency band, and sets a gain flag (GAINFflag) to OFF ( Step S11). GAINFflag = ON indicates that the gain of the AGC amplifier 203 is higher than the threshold value, that is, the signal level (input level) of the broadcast signal is lower than the reference value, and GAINFflag = OFF indicates that the gain of the AGC amplifier 203 is It indicates that it is lower than the threshold value, that is, the signal level (input level) of the broadcast signal is higher than the reference value.

  The TV application program 101 controls the channel selection unit 202 to change the reception target channel to the frequency band specified by the variable CH (step S12). Then, the TV application program 101 refers to the output result of the demodulation unit 204, the intermediate frequency signal, and the like via the controller 205, so that there is a valid signal that can be viewed in the current frequency band of the reception target channel. It is determined whether or not the current reception target channel is a valid channel (step S13). When the current reception target channel is an effective channel, the TV application program 101 acquires the current gain level of the AGC amplifier 203 via the controller 205 (step S14), and the current gain level of the AGC amplifier 203 (AGC It is determined whether or not (adjustment value) exceeds a threshold value (step S15). If the current gain level (AGC adjustment value) exceeds the threshold value, the TV application program 101 sets the gain flag (GAINFflag) to ON (step S16).

  Next, the TV application program 101 determines whether or not the frequency band indicated by the variable CH is the last frequency band in the scan target frequency band (step S17). If the frequency band indicated by the variable CH is not the last frequency band, the TV application program 101 changes the value of the variable CH to a value indicating the next frequency band (step S18), and thereafter the process of step S12 described above. Migrate to

  If the frequency band indicated by the variable CH is the last frequency band, the TV application program 101 determines whether the gain flag (GAINFflag) is ON or OFF (step S19). If GAINFflag is OFF (NO in step S19), the TV application program 101 sets the amplifier (AMP) 200 to an off state by transmitting a command for specifying booster off to the controller 205 (step S20). When the amplifier (AMP) 200 is set to the off state, the broadcast signal distributed by the distribution circuit 201 is not amplified by the amplifier (AMP) 200, for example, in a state where the amplifier (AMP) 200 is bypassed. To the tuner 123B. On the other hand, if GAINFflag is ON (YES in step S19), the TV application program 101 sets the amplifier (AMP) 200 to the on state by transmitting a command for specifying booster on to the controller 205 (step S21). ). When the amplifier (AMP) 200 is set to the on state, the signal level of the broadcast signal distributed by the distribution circuit 202 is increased by the amplifier (AMP) 200 and then sent to the tuner 123B.

  In this way, at the time of channel scanning, processing for detecting each effective channel from within the frequency band to be scanned and whether or not the gain level of the AGC amplifier 203 exceeds the threshold value for each effective channel are checked. If there is any effective channel whose gain level exceeds the threshold, the amplifier (AMP) 200 is set to the on state, and there is no effective channel whose gain level exceeds the threshold. Only when not, the amplifier (AMP) 200 is set to the OFF state.

  In an on-air reception environment, the signal level of each effective channel may vary depending on the time zone, and even if the signal level is higher than the reference level during channel scanning, the signal level may be the reference level depending on the time zone. There is also a possibility of lowering. On the other hand, for broadcast signals from the CATV network, the signal levels of all channels are usually uniform and the signal levels of all channels are high. For this reason, in this embodiment, when there is even one effective channel whose gain level is higher than the threshold value, the current reception environment is an on-air reception environment and the broadcast signal input level is relatively weak. And the amplifier (AMP) 200 is set to the on state. As a result, the reception level in the on-air reception environment can be optimized with simpler control than when individual amplifiers (AMP) 200 are turned on / off for each effective channel. In addition, when there is no effective channel whose gain level is higher than the threshold value, the amplifier (AMP) 200 is set to an off state. Therefore, even when the broadcast signal input terminal 18 is connected to the CATV network, there are many cases. It is not affected by wave interference.

  Next, signal level control processing corresponding to each of the “auto” mode, “on” mode, and “off” mode will be described with reference to the flowchart of FIG.

  The TV application program 101 determines whether the current boost setting mode is the “auto” mode, the “on” mode, or the “off” mode (step S31). If the current boost setting mode is the “auto” mode, the TV application program 101 executes the process described with reference to the flowchart of FIG. 5 when executing the channel scan (step S32). On the other hand, when the boost setting mode is set to the “on” mode by the operation of the input device by the user, the TV application program 101 transmits a command for designating booster on to the controller 205 at that time, The amplifier (AMP) 200 is set to an on state (step S33). When the boost setting mode is set to the “off” mode by the operation of the input device by the user, the TV application program 101 transmits a command for designating booster off to the controller 205 at that time, The amplifier (AMP) 200 is set to an off state (step S34).

  When the boost setting mode is the “on” mode or the “off” mode, only a normal channel scan process (a process for detecting an effective channel) is executed during the channel scan.

  Next, the relationship between the AGC gain level corresponding to each effective channel (broadcast station) detected by the channel scan and the on / off setting of the amplifier (AMP) 200 will be described with reference to FIGS.

  FIG. 7 shows a case where the AGC gain levels corresponding to three effective channels among all effective channels (broadcast stations 1 to 10) exceed the threshold value. In this case, the amplifier (AMP) 200 is set to an on state. FIG. 8 shows a case where the AGC gain levels corresponding to all the effective channels are equal to or less than the threshold value. In this case, the amplifier (AMP) 200 is set to an off state. FIG. 9 shows a case where only the AGC gain level corresponding to one effective channel among all effective channels exceeds the threshold value. In this case, the amplifier (AMP) 200 is set to an on state.

  Depending on the reception area, the signal level of the on-air reception environment may be relatively different for each channel. In this case, by checking the signal level for each effective channel, a gain flag table indicating gain flags corresponding to each effective channel as shown in FIG. 10 may be generated. This gain flag table may be generated at the time of channel scanning, for example. Then, the TV application program 101 uses an amplifier (AMP) for each reception target channel received by the second tuner 123B based on the detection result of each of the plurality of effective channels, that is, based on the gain flag table of FIG. 200 is set to an on state or an off state.

  Hereinafter, a process of turning on / off the amplifier (AMP) 200 for each reception target channel to be received by the second tuner 123B will be described with reference to the flowchart of FIG.

  The TV application program 101 receives broadcast program data or electronic program information (EPG) by selectively using the two tuners 123A and 123B. For example, when the first tuner 123A is in use for receiving broadcast program data of a channel, the TV application program 101 is for receiving broadcast program data of another channel or receiving electronic program information (EPG). The second tuner 123B is selected (step S41). Then, the TV application program 101 instructs the second tuner 123B to receive the reception target channel. In this case, the TV application program 101 reads the gain flag corresponding to the reception target channel from the gain flag table of FIG. 10, and checks the value of the gain flag (step S42). If the gain flag corresponding to the reception target channel is OFF (NO in step S43), the TV application program 101 transmits a command for designating booster off to the controller 205 of the first tuner 123A, so that the amplifier ( (AMP) 200 is set to an off state (step S44). On the other hand, if the gain flag corresponding to the reception target channel is ON (YES in step S43), the TV application program 101 transmits a command for designating booster on to the controller 205 of the first tuner 123A, thereby the amplifier. (AMP) 200 is set to an on state (step S45).

  When the reception target channel to be received is switched by the second tuner 123B (YES in step S46), the TV application program 101 sets the gain flag corresponding to the new reception target channel to be switched to the gain flag table in FIG. The amplifier (AMP) 200 is set to an on state or an off state according to the gain flag (steps S42 to S45).

  In this way, by controlling on / off of the amplifier (AMP) 200 for each channel individually, even in a reception environment where the difference in signal level between channels is relatively large, the second tuner 123B broadcasts each channel. The signal can be received normally.

  As described above, according to the present embodiment, ON / OFF of the amplifier (AMP) 200 is automatically controlled according to the signal level of the broadcast signal. Therefore, the signal level of the broadcast signal input to the second tuner 123B can be optimized without the user being aware of the broadcast signal reception environment (on-air reception environment, CATV environment, etc.) of the computer. . Therefore, in any of various reception environments such as an on-air reception environment and a CATV environment, the first tuner 123A can normally receive the broadcast signal, but the second tuner 123B cannot normally receive the broadcast signal. Can be prevented.

  In this embodiment, the example in which the signal level of the broadcast signal input to the first tuner 123A is detected using the gain level of the AGC amplifier 203 in the first tuner 123A has been described. A signal level detection circuit may be arranged at the front stage or the rear stage of 202, and the signal level of the broadcast signal input to the first tuner 123A may be detected using the signal level detection circuit.

  In the present embodiment, the example in which the amplifier (AMP) 200 is provided in the first tuner 123A has been described. However, the amplifier (AMP) 200 may be provided in the second tuner 123B.

  In addition, since all functions of the TV application program 101 of the present embodiment can be realized by software, the software is provided with two tuners connected in cascade through a computer-readable storage medium storing the software. The effects similar to those of the present embodiment can be easily realized simply by being installed in a normal computer.

  Further, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine a component suitably in different embodiment.

  101 ... TV application program, 123A, 123B ... tuner, 18 ... broadcast signal input terminal, 200 ... amplifier, 201 ... distribution circuit.

Claims (7)

A first tuner for receiving a television broadcast signal input from a broadcast signal input terminal;
A second tuner for receiving a television broadcast signal distributed from the first tuner by the distribution circuit provided in the first tuner,
Signal level detection means for detecting a signal level of a television broadcast signal input to the first tuner;
Setting screen for allowing the user to designate one of the first mode, the second mode, and the third mode as a mode for the boost function for increasing the signal level of the television broadcast signal input to the second tuner Setting screen means for displaying on the display;
When the first mode is designated by the operation of the input device, an amplifier for increasing the signal level of the television broadcast signal distributed to the second tuner according to the detected signal level is turned on. Or, when either the second mode or the third mode is designated by the operation of the input device, regardless of the detection result of the signal level by the signal level detection means, An information processing apparatus comprising: control means for setting the amplifier to either an on state or an off state . The signal level detection means detects a signal level corresponding to each of a plurality of effective channels of a television broadcast signal input to the first tuner,
When the first mode is designated , the control means sets the amplifier to an on state when there is an effective channel whose signal level is lower than a reference level among the plurality of effective channels, 2. The information processing apparatus according to claim 1, wherein the amplifier is set to an off state when there is no effective channel having a signal level lower than the reference level among the effective channels. The signal level detection means detects a signal level corresponding to each of a plurality of effective channels of a television broadcast signal input to the first tuner,
When the first mode is designated , the control means turns on the amplifier for each reception target channel received by the second tuner based on the detection result of the signal level of each of the plurality of effective channels. The information processing apparatus according to claim 1, wherein the information processing apparatus is set to an off state. A first tuner for receiving a television broadcast signal input from a broadcast signal input terminal;
A second tuner for receiving a television broadcast signal distributed from the first tuner by the distribution circuit provided in the first tuner,
A signal level detecting means for performing a channel scan for detecting a plurality of effective channels of a television broadcast signal input to the first tuner, and detecting a signal level of each of the plurality of effective channels;
Setting screen for allowing the user to designate one of the first mode, the second mode, and the third mode as a mode for the boost function for increasing the signal level of the television broadcast signal input to the second tuner Setting screen means for displaying on the display;
When the first mode is designated by the operation of the input device, if there is an effective channel whose signal level is lower than a reference level among the plurality of effective channels, the television distributed to the second tuner In order to increase the signal level of the broadcast signal, an amplifier provided in the first tuner is set to an ON state, and there is no effective channel whose signal level is lower than the reference level among the plurality of effective channels. In this case , the amplifier is set to an off state, and when either the second mode or the third mode is designated by the operation of the input device, regardless of the detection result of the signal level by the signal level detection means the information processing instrumentation, characterized in that and a control means for setting the amplifier either on or off . The signal level of the television broadcast signal distributed from the first tuner to the second tuner is controlled by a distribution circuit provided in the first tuner that receives the television broadcast signal input from the broadcast signal input terminal. A signal level control method for
A signal level detection step of detecting a signal level of a television broadcast signal input to the first tuner;
Setting screen for allowing the user to designate one of the first mode, the second mode, and the third mode as a mode for the boost function for increasing the signal level of the television broadcast signal input to the second tuner Displaying on the display;
When the first mode is designated by the operation of the input device, an amplifier for increasing the signal level of the television broadcast signal distributed to the second tuner according to the detected signal level is turned on. Or when either of the second mode or the third mode is designated by the operation of the input device, the amplifier is turned on regardless of the detection result of the signal level. A signal level control method comprising: a control step of setting any of the OFF states . The signal level detecting step detects a signal level corresponding to each of a plurality of effective channels of a television broadcast signal input to the first tuner,
When the first mode is designated , the control step sets the amplifier to an ON state when there is an effective channel whose signal level is lower than a reference level among the plurality of effective channels, 6. The signal level control method according to claim 5, wherein when there is no effective channel having a signal level lower than a reference level among the effective channels, the amplifier is set to an off state. The signal level detecting step detects a signal level corresponding to each of a plurality of effective channels of a television broadcast signal input to the first tuner,
In the control step, when the first mode is designated , the amplifier is turned on for each reception target channel received by the second tuner based on the detection result of the signal level of each of the plurality of effective channels. 6. The signal level control method according to claim 5 , wherein the signal level is set to an off state.

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