JP2015026887A - Receiving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a convenient receiving device which allows a user to identify a channel on which an image of a monitor camera is distributed, without a special operation.SOLUTION: A mixer 42 mixes a RF signal obtained by modulating an output signal of imaging means 3 into a predetermined RF band by an OFDM modulator 41 and a broadcast signal received by an antenna 2 and inputs the mix signal to a receiving device 5. The receiving device 5 identifies a channel relating to the RF signal from a channel selectable with a tuner, and displays an image on a display 6.

Description

  The present invention relates to a receiving apparatus that receives a broadcast signal and a terrestrial digital broadcast signal from a surveillance camera.

  In recent years, surveillance cameras are often installed indoors and / or outdoors even in ordinary households from the viewpoint of crime prevention. Surveillance camera images can be viewed with the receiver, but especially in condominiums with common hearing facilities, the surveillance camera images can be viewed in the condominium's manager's room and each home's receiver using the common hearing facilities. System may be constructed.

  Specifically, the output signal of the surveillance camera is frequency-converted to an RF signal of a predetermined RF band by an OFDM modulator and output to a mixer provided in the hearing equipment. The mixer mixes the RF signal and the terrestrial digital broadcast signal received by the antenna and distributes them to each receiving device. As a result, the video of the monitoring camera can be viewed in the manager room or the receiving device in each home (see Patent Document 1).

  By the way, in the above system, the output signal of the surveillance camera is input to the receiving device together with the terrestrial digital broadcast signal. The receiving apparatus sequentially scans frequencies (UFH13 to UFH62) assigned to terrestrial digital broadcasting to find a receivable broadcast station, so-called channel scan is executed, so that a broadcast station that can also receive video from a surveillance camera is received. Detect as one of

Utility model registration No. 316938

  However, the receiving apparatus cannot identify which channel is the video of the surveillance camera among the channels found as a result of executing the channel scan. Therefore, the user has to manually set a channel to which the video of the surveillance camera is distributed in order to view the video of the surveillance camera.

  In view of the above-described problems, an object of the present invention is to provide a highly convenient receiving apparatus.

  In order to achieve the above object, the receiving apparatus of the present invention can select a tuner to which a mixed signal of an RF signal obtained by modulating the output signal of the imaging means into a predetermined RF band and a broadcast signal is input, and the tuner. And a specifying unit that specifies a channel related to the RF signal from the channel.

  In the receiving apparatus having the above-described configuration, it is preferable that the specifying unit specifies a channel related to content not encrypted with a scramble key as a channel related to the RF signal.

  The receiving apparatus having the above-described configuration preferably includes an extraction unit that extracts time information from a broadcast signal and a time setting unit that sets time based on the time information extracted by the extraction unit.

  The receiving apparatus having the above-described configuration preferably includes an information presenting unit that presents information indicating a channel related to the RF signal identified by the identifying unit.

  In the receiving apparatus having the above-described configuration, it is preferable that the receiving apparatus includes a switching instruction unit that instructs to switch the channel selected by the tuner to the channel related to the RF signal specified by the specifying unit.

  According to the present invention, a mixed signal of an RF signal obtained by modulating a broadcast signal output from the image pickup unit into a predetermined RF band and a terrestrial digital broadcast signal is input to the tuner. The tuner can select a plurality of channels, and the specifying unit specifies a channel related to the RF signal from the plurality of channels. That is, the user's convenience is improved because it is specified on which channel the video of the surveillance camera is broadcast without any special operation by the user.

Diagram showing the configuration of the hearing system The block diagram which shows an example of a structure of the receiver of 1st Embodiment. FIG. 2 is a block diagram illustrating an example of a configuration of a tuner of the receiving device illustrated in FIG. The figure which shows the 1st example of the OSD screen displayed on a display apparatus. The figure which shows the 2nd example of the OSD screen displayed on a display apparatus. The flowchart which shows an example of the process which the control part of the receiver of 1st Embodiment performs The flowchart which shows an example of the process which the control part of the receiver of 2nd Embodiment performs The flowchart which shows an example of the process which the control part of the receiver of 3rd Embodiment performs The flowchart which shows an example of the process which the control part of the receiver of 4th Embodiment performs The flowchart which shows an example of the process which the control part of the receiver of 5th Embodiment performs

<First Embodiment>
First, a hearing system will be described with reference to FIG. The common hearing system is a system that allows users to view digital terrestrial broadcasting in a building by sharing one antenna in an apartment building such as an office building or a condominium / apartment. In office buildings and apartment buildings, surveillance cameras are attached to shoot inside and outside the site. The captured video is displayed on the display device via a receiving device installed in the guard room or the manager room. That is, the hearing system 1 of the present embodiment includes an antenna 2 that receives a terrestrial digital broadcast signal, a monitoring camera 3, a hearing facility 4 that receives the terrestrial digital broadcasting signal and the broadcasting signal of the monitoring camera 3, a receiving device 5, and A display device 6 is provided.

  The hearing equipment 4 modulates an output signal including a video signal and an audio signal output from the surveillance camera 3 into a predetermined RF band, an RF signal modulated by the OFDM modulator 41 and an input from the antenna 2. And a mixer 42 for mixing the digital terrestrial broadcasting signal thus generated and generating a mixed signal.

  More specifically, the OFDM modulator 41 converts the output signal of the surveillance camera 3 into a digital broadcast standard OFDM signal, and converts the frequency into a predetermined RF band to generate an RF signal. The mixed signal generated by the mixer 42 is output from the mixer 42 to the receiving device 5.

  In the present embodiment, the common hearing facility 4 includes the OFDM modulator, but the common hearing facility 4 may not include the OFDM modulator. In that case, the OFDM modulator is arranged between the monitoring camera 3 and the hearing equipment 4. Alternatively, the monitoring camera 3 may have an OFDM modulator (having a modulation function), and the output signal of the monitoring camera 3 may be an RF signal.

  In the above description, an office building or an apartment house has been described as an example of a common hearing system. However, the present invention is not limited to this and can be applied to small-scale facilities and houses such as single-family houses. Further, in the following, a case where the receiving system 5 is specifically installed in a manager's room and is a consonant system in an apartment will be described as an example. However, the receiving apparatus 5 can be installed not only in the manager's room but also in each dwelling unit. It is.

  Hereinafter, the receiving apparatus of this embodiment will be described with reference to FIGS. The embodiment described below shows an example of a receiving device in order to embody the technical idea of the present invention, and is not intended to identify the present invention as a receiving device. It is equally applicable to the apparatus of other embodiments within the scope of the claims.

  FIG. 2 is a block diagram showing an example of the configuration of the receiving apparatus of this embodiment. FIG. 3 is a diagram showing an example of the configuration of the tuner of FIG. In the present embodiment, the receiving apparatus 5 is described as including one tuner 11, but may be provided with two or more tuners 11. The tuner 11 acquires the output signal (mixed signal) of the mixer 42. Then, the tuner 11 multiplies the mixed signal by a local oscillation signal having a frequency corresponding to the selected channel and converts the frequency into a baseband signal.

  Hereinafter, the tuner 11 will be described in detail with reference to FIG. The tuner 11 includes an input terminal 31, a first variable gain device 32, a first filter 33, a second variable gain device 34, a mixer 35, a local oscillator 36, a second filter 37, a third variable gain device 38, and An output terminal 39 is provided.

  A mixed signal is input to the input terminal 31. The first variable gain device 32 is a low noise amplifier having a low noise figure (NF) in order to ensure sound quality, image quality, etc. when the level of the mixed signal input to the input terminal 31 is small.

  The first filter 33 selects only the reception band (all reception broadcast frequency bands) from the output signal of the first variable gain device 32 and removes other frequency components. For example, when the terrestrial digital broadcast is selected by the user, the frequency band other than the terrestrial digital broadcast is removed.

  The gain of the output signal of the first filter 33 is adjusted by the second variable gain device 34. The mixer 35 multiplies the output signal of the second variable gain device 34 by the local oscillation signal output from the local oscillator 36 and converts the frequency into a baseband signal.

  The second filter 37 smoothes the baseband signal output from the mixer 35, that is, attenuates the high frequency component and outputs it. The gain of the output signal of the second filter 37 is adjusted by the third variable gain device 38. The output signal of the third variable gain device 38 is output from the output terminal 39 to the demodulator 12.

  Returning to FIG. 2, the description of the receiving device 5 will be continued. The demodulator 12 demodulates the output signal from the output terminal 39 and outputs a demodulated signal. Digital terrestrial broadcast signals are generally scrambled (encrypted) with a scramble key. A release key for releasing the scramble is included in the terrestrial digital broadcast signal, and this release key is a master key (authentication information) possessed by an IC card called a B-CAS (registered trademark) card connected to the receiving device 5. Is taken out by The demodulator 12 de-scrambles the terrestrial digital broadcast signal using the extracted release key and performs demodulation processing.

  The error correction unit 13 performs error correction on the output signal of the demodulator 12 as necessary. The demultiplexing unit 14 separates and decodes the output signal of the error correction unit 13 into audio data (audio signal), video data (video signal), and EPG data, and each of them is sent to the audio decoder 15, the video decoder 16, and a control unit 20 described later. Supply.

  The audio decoder 15 decodes the input audio data by, for example, the MPEG system and outputs it to a speaker or the like. The video decoder 16 decodes the input video data by, for example, the MPEG system and supplies it to the frame memory 17.

  The frame memory 17 is a memory area for temporarily storing video data. The video processing unit 18 converts the video data stored in the frame memory 17 into a video signal suitable for display on a display (not shown) and outputs the video signal to the display.

  The video processing unit 18 receives the OSD signal output from the OSD generation unit 19, generates a video signal in which the OSD signal is superimposed on the video data stored in the frame memory 17, and is suitable for display on a display. Convert to signal and output to display.

  The OSD generation unit 19 generates an OSD screen such as characters and graphics, and outputs an OSD signal obtained by converting the generated OSD screen to the video processing unit 18.

  The control unit 20 is a control unit that controls the entire receiving device 5. The control unit 20 includes a specification unit 201, an extraction unit 202, a time setting unit 203, an information presentation unit 204, and a switching instruction unit 205. In the present embodiment, for simplification of description, a configuration in which one control unit 20 includes a specifying unit 201, an extraction unit 202, a time setting unit 203, an information presentation unit 204, and a switching instruction unit 205 is shown. The structure which a different control part has may be sufficient.

  The specifying unit 201 is a specifying unit that specifies a channel related to an RF signal from channels that can be selected by the tuner 11. In other words, the specifying unit 201 specifies in which channel the video of the monitoring camera 3 can be viewed. Until the specifying unit 201 completes specifying the channel related to the RF signal, the display device 6 displays an OSD screen indicating that it is being specified (detecting), for example, as shown in FIG. The OSD screen shown in FIG. 4 is generated by the OSD generation unit 19. A method for specifying a channel related to the RF signal will be described later.

  The extraction unit 202 is extraction means for extracting time information from the terrestrial digital broadcast signal. The time information is included in the EPG data described above, and the extraction unit 202 extracts time information from the time information included in the EPG data.

  The time setting unit 203 is a time setting unit that sets the time of the internal clock of the reception device 5 based on the time information extracted by the extraction unit 202. The video of the monitoring camera 3 can be recorded by storing it in the storage unit 21 described later. The video of the monitoring camera 3 displayed on the display device 6 may be a current video or a recorded past video. The video of the monitoring camera 3 indicates when the video was taken. This is important information. Therefore, it is desirable that the time of the internal clock of the receiving device 5 is an accurate time. Therefore, in this embodiment, the time setting unit 203 sets the time of the internal clock of the receiving device 5 regularly or irregularly based on the time information extracted by the extracting unit 202, so that there is an error in the time of the internal clock of the receiving device 5. It becomes difficult to occur.

  The information presenting unit 204 is a presenting unit that presents information indicating the channel related to the RF signal identified by the identifying unit 201. As a presentation method, for example, the OSD generation unit 19 generates an OSD screen indicating how many channels related to the RF signal are as shown in FIG. 5, and displays the OSD screen 100 on the display device 6. The presentation method is not limited to display on the display device 6 and may be presentation by voice guidance.

  The switching instruction unit 205 is a switching instruction unit that instructs to switch the channel selected by the tuner 11 to the channel related to the RF signal specified by the specifying unit 201. Since the switching instruction unit 205 automatically switches the channel to the channel on which the video of the monitoring camera 3 is broadcast without requiring a user to switch the channel, the convenience is high.

  It should be noted that only one or both of the presentation of the information shown in the channel related to the RF signal by the information presentation unit 204 and the switching to the channel related to the RF signal by the switching instruction unit 205 may be executed. It is good to do. As shown in FIG. 5, by executing both processes, the video of the monitoring camera 3 can be automatically viewed, and the channel to be designated when the video of the monitoring camera 3 is subsequently viewed is recognized. Therefore, it is preferable to execute either one of them. In addition, in FIG. 5, the image | video when the surveillance camera 3 is installed in front of an elevator is displayed as an example.

  The storage unit 21 is a storage unit that stores the video of the monitoring camera 3.

  Hereinafter, processing executed by the control unit 20 of the receiving device 5 according to the present embodiment will be described with reference to FIG. FIG. 6 is a flowchart illustrating an example of processing executed by the control unit 20 of the receiving device 5 according to the present embodiment.

  In step S01, the control unit 20 performs a channel scan. The channel scan is an operation for detecting channels that can be selected by the tuner 11 and registering them in the channel map.

  In step S <b> 02, the specifying unit 201 of the control unit 20 specifies a channel that is not scrambled from channels that can be selected by the tuner 11. That is, in step S01, channels that can be selected by the tuner 11 can be detected, but it is not specified which channel is the channel on which the video of the monitoring camera 3 is broadcast. Therefore, in this step, it is specified which channel is a channel that has not been scrambled.

  In step S03, the specifying unit 201 of the control unit 20 specifies the channel specified in step S02 as the channel on which the video of the monitoring camera 3 is broadcast.

  That is, as described above, the terrestrial digital broadcast signal is scrambled, and the demodulator 12 demodulates the scramble and performs the demodulation process. On the other hand, the RF signal is not scrambled and can be demodulated without releasing the scramble. That is, the video of the monitoring camera 3 can be viewed even if a B-CAS (registered trademark) card is not connected to the receiving device 5, and the specifying unit 201 can specify the channel related to the RF signal depending on the presence or absence of scrambling. In other words, the identifying unit 201 identifies a channel that can be viewed without a B-CAS (registered trademark) card, and identifies the channel as a channel related to an RF signal.

  According to this embodiment, the tuner receives a mixed signal of an RF signal obtained by modulating the output signal of the imaging means into a predetermined RF band and a terrestrial digital broadcast signal. The tuner can select a plurality of channels, and the specifying unit specifies a channel related to the RF signal from the plurality of channels. That is, the user's convenience is improved because it is specified on which channel the video of the surveillance camera is broadcast without any special operation by the user.

Second Embodiment
FIG. 7 is a flowchart illustrating an example of processing executed by the control unit 20 of the receiving device 5 according to the present embodiment. Step S11 in the flowchart in FIG. 7 is the same as step S01 in the flowchart in FIG.

  In the first embodiment, the channel related to the RF signal is specified based on the presence or absence of scrambling. However, the method for specifying the channel related to the RF signal is not limited to this. Hereinafter, the second and third embodiments relate to other methods for specifying a channel related to an RF signal. In this embodiment, the channel related to the RF signal is specified based on the degree of movement in the video.

  That is, the video of the monitoring camera 3 does not move unless there is a moving body (person, bicycle, etc.) in the imaging area of the monitoring camera 3, and even if there is a moving body, the moving body is at a predetermined speed in a predetermined direction. In many cases, the movement is continuous enough to move.

  On the other hand, terrestrial digital broadcast programs are very rare in movement, and many programs are shot by a plurality of cameras, and images are frequently switched to produce effective images. Therefore, there are cases where the image data before and after the image is not continuous, and the movement of the moving body in the video tends to be larger than the movement of the moving body in the video of the surveillance camera 3.

  Therefore, in the present embodiment, the video of each channel is received for a certain period of time, the degree of motion in the video is detected, and compared, and the channel related to the video with the smallest degree of motion is identified as the channel related to the RF signal.

  In step S <b> 12, the specifying unit 201 of the control unit 20 specifies the channel with the smallest degree of motion in the video from the channels that can be selected by the tuner 11. For example, the channel with the smallest degree of motion in the video is specified based on the degree of motion (change) of the object in the image data detected between the image data of the current frame and the image data of the previous frame.

  In step S13, the specifying unit 201 of the control unit 20 specifies the channel specified in step S12 as the channel on which the video of the monitoring camera 3 is broadcast.

  Note that the method of receiving a video for a certain period of time and specifying the channel related to the RF signal is not limited to the method of specifying based on the degree of motion, and may be specified based on the degree of luminance of the video, for example. . Digital terrestrial broadcast programs are produced using many lights and have high brightness. Compared to this, the video of the surveillance camera 3 has a low luminance because natural light (sunlight) or light other than street lights may not easily enter. Therefore, the video of each channel is received for a certain period of time, and the channel having the lowest average luminance of the video is specified as the channel related to the RF signal.

  According to the present embodiment, the same effects as those of the first embodiment can be obtained.

<Third Embodiment>
FIG. 8 is a flowchart illustrating an example of processing executed by the control unit 20 of the receiving device 5 according to this embodiment. Step S21 in the flowchart in FIG. 8 is the same as step S01 in the flowchart in FIG.

  In the present embodiment, the channel related to the RF signal is specified based on broadcast station information included in the EPG data. As described above, the demultiplexer 14 separates and decodes the output signal of the error corrector 13 into audio data, video data, and EPG data. The EPG data includes information indicating the name of the broadcasting station that broadcasts the program.

  Therefore, in this embodiment, the channel whose broadcast station name included in the EPG data is the broadcast station name related to the monitoring camera is specified as the channel related to the RF signal.

  In step S22, the specifying unit 201 of the control unit 20 specifies a channel whose broadcast station name is the name of the broadcast station related to the monitoring camera from the channels that can be selected by the tuner 11. For example, a channel including a character string set by the monitoring camera 3 as a broadcasting station name (for example, “monitoring camera” or “camera”) or a channel whose broadcasting station name is blank (blank) is specified.

  In step S23, the specifying unit 201 of the control unit 20 specifies the channel specified in step S22 as the channel on which the video of the monitoring camera 3 is broadcast.

  In this embodiment, the channel that is the broadcast station name related to the monitoring camera 3 is positively specified. However, the channel related to the monitoring camera 3 may be specified by an erasing method. The receiving device 5 generally has regional information about the region. In the area information, the area and the broadcast station name are associated with each other.

  Therefore, first, the specifying unit 201 compares the broadcast station name included in the area information of the area where the receiving device 5 is installed with the broadcast station name included in the EPG data of each channel, and the broadcast station included in the area information. Identify channels broadcast by other broadcast stations. And it is good also as specifying the channel currently broadcast by broadcast stations other than a broadcast station as the channel which concerns on RF signal.

  According to the present embodiment, the same effects as those of the first embodiment can be obtained.

<Fourth embodiment>
FIG. 9 is a flowchart illustrating an example of processing executed by the control unit 20 of the receiving device 5 according to this embodiment. Steps S31 and S32 in the flowchart in FIG. 9 are the same as steps S01 and S02 in the flowchart in FIG.

  In the first embodiment, a channel that is not scrambled among a plurality of channels detected by channel scanning is specified as a channel related to an RF signal. If there is one unscrambled channel identified by the identifying unit 201, it is sufficient to identify that channel as a channel related to the RF signal as described above, but there are a plurality of unscrambled channels. It can be considered that there are pieces.

  Therefore, in this embodiment, it is determined whether or not there are a plurality of scrambled channels (step S33). If there is one scrambled channel (Y in step S33), the process proceeds to step S34. A channel that is not scrambled is identified as a channel related to the RF signal (the same processing as step S03 in FIG. 6).

  On the other hand, if the number of unscrambled channels is not one, that is, two or more (NO in step S33), the process proceeds to steps S35 and S36, and the channel related to the RF signal is selected from the unscrambled channel. Identify.

  As a method for specifying a channel related to an RF signal from channels that have not been scrambled, for example, the specifying method of the second embodiment and / or the specifying method of the third embodiment described above may be used. The case where it specifies with the specifying method of 2nd Embodiment is demonstrated to an example.

  In step S35, the specifying unit 201 of the control unit 20 receives the video of each channel for a certain period of time for a plurality of channels that are not scrambled, detects the degree of motion in the video, and compares them to compare the degree of motion most. Identify a channel related to a small video.

  In step S36, the specifying unit 201 of the control unit 20 specifies the channel specified in step S35 as the channel on which the video of the monitoring camera 3 is broadcast.

  In the present embodiment, the channel related to the RF signal is specified by combining the specifying method of the first embodiment and the specifying method of the second embodiment described above. However, the combination is not limited to this, and the first method described above. What is necessary is just to combine the specific method of embodiment-3rd Embodiment suitably.

  According to the present embodiment, the same effects as those of the first embodiment can be obtained. In addition, since the channel related to the RF signal is specified from the channels that can be selected by the tuner by a plurality of specifying methods, the channel related to the RF signal can be specified with high accuracy.

<Fifth Embodiment>
FIG. 10 is a flowchart illustrating an example of processing executed by the control unit 20 of the receiving device 5 according to the present embodiment. Step S41 in the flowchart in FIG. 10 is the same as step S01 in the flowchart in FIG.

  As described above, the time information is one of important information in the receiving device that receives the video of the monitoring camera 3. The receiving device 5 has an internal clock, and the time setting can be changed manually by operating the remote controller of the receiving device 5, but if set manually, there is a high possibility that an error will occur from the actual time. If the time is not adjusted frequently, an error may occur in the time measurement of the internal clock as time elapses, and the time may be gradually advanced or delayed.

  Therefore, in this embodiment, in addition to the processing shown in each of the embodiments described above, the time setting processing of the internal clock of the receiving device 5 is performed based on the time information included in the EPG data of the terrestrial digital broadcast signal. That is, this embodiment is executed in combination with the first to fourth embodiments.

  FIG. 10 is a flowchart illustrating an example of processing executed by the control unit 20 of the receiving device 5 according to the present embodiment. More specifically, FIG. 10 is a flowchart illustrating a flow of processing for setting the time of the internal clock of the receiving device 5. Step S41 in the flowchart in FIG. 10 is the same as step S01 in the flowchart in FIG.

  In step S <b> 42, the specifying unit 201 of the control unit 20 specifies a scrambled channel from the channels that can be selected by the tuner 11.

  In step S43, the extraction unit 202 of the control unit 20 acquires EPG data of the broadcast signal (digital terrestrial broadcast signal) of the channel specified in step S42, and extracts time information from the EPG data. If there are a plurality of scrambled channels, EPG data may be acquired from the terrestrial digital broadcast signal of any channel. When acquiring time information from EPG data of a terrestrial digital broadcast signal of a specific broadcast station (for example, a public broadcast station), in addition to or instead of the process of step S42, the broadcast station name included in the EPG data is changed. It is only necessary to acquire information to indicate a channel related to a specific broadcasting station.

  In step S44, the time setting unit 203 of the control unit 20 sets the time of the internal clock of the receiving device 5 based on the time information extracted by the extraction unit 202. The process of the flowchart of FIG. 10 is executed at the time of initial setting (at the time of channel scanning) and thereafter periodically or irregularly.

  According to the present embodiment, since the time of the internal clock of the receiving device is automatically set based on the time information included in the EPG data of the terrestrial digital broadcast signal, an error hardly occurs in the time of the internal clock. In addition, since the time setting process is performed regularly or irregularly, it is possible to prevent the time of the internal clock from being advanced or delayed over time.

DESCRIPTION OF SYMBOLS 1 Hearing system 2 Antenna 3 Surveillance camera 4 Hearing equipment 5 Reception apparatus 6 Display apparatus 11 Tuner 12 Demodulator 13 Error correction part 14 Demultiplexing part 15 Audio decoder 16 Video decoder 17 Frame memory 18 Image processing part 19 OSD generation part 20 Control unit 21 Storage unit 31 Input terminal 32 First variable gain device 33 First filter 34 Second variable gain device 35 Mixer 36 Local oscillator 37 Second filter 38 Third variable gain device 39 Output terminal 41 OFDM modulation Unit 42 Mixer 201 Identification unit 202 Extraction unit 203 Time setting unit 204 Information presentation unit 205 Switching instruction unit

Claims (5)

A tuner to which a mixed signal of an RF signal obtained by modulating the output signal of the imaging means into a predetermined RF band and a broadcast signal is input;
A specifying unit for specifying a channel related to the RF signal from channels that can be selected by the tuner;
Receiving device comprising   The receiving device according to claim 1, wherein the specifying unit specifies a channel related to content not encrypted with a scramble key as a channel related to the RF signal.   The receiving device according to claim 1, further comprising: an extracting unit that extracts time information from a broadcast signal; and a time setting unit that sets time based on the time information extracted by the extracting unit.   The receiving device according to claim 1, further comprising: an information presenting unit that presents information indicating a channel related to the RF signal identified by the identifying unit.   5. The receiving device according to claim 1, further comprising: a switching instruction unit that instructs to switch a channel selected by the tuner to a channel related to the RF signal specified by the specifying unit.