JP6182952B2 - Broadcast receiving apparatus, broadcast receiving method, and broadcast receiving program - Google Patents

Description

  The present invention relates to a broadcast receiving apparatus, a broadcast receiving method, and a broadcast receiving program.

  Recently, some small communication terminals such as mobile phones have a full-segment tuner. The band of each channel of terrestrial digital broadcasting is divided into 13 areas, and only one area is used in one-segment broadcasting. On the other hand, since all the areas are used in full-segment broadcasting, the amount of data transmitted to the LCD display panel is larger than in one-segment broadcasting, and terrestrial digital broadcasting can be displayed with high resolution.

  However, in full-seg broadcasting, there are cases where the S / N ratio deteriorates due to unnecessary radiation generated in the apparatus and a predetermined channel cannot be received or the display image quality of the channel deteriorates. When the communication terminal displays a video on the LCD display panel, the processor generates a video signal and transmits the video signal to the LCD display panel at a predetermined LCD operation clock. The video signal is transmitted via a flexible cable connecting the LCD display panel and the processor. At this time, unnecessary radiation is generated by the flexible cable, and the antenna of the communication terminal may receive the unnecessary radiation together with a broadcast wave of digital terrestrial broadcasting. And this unnecessary radiation may cause noise in terrestrial digital broadcasting.

  Unwanted radiation has multiple harmonic components, some of which overlap the terrestrial digital reception band. In 1Seg broadcasting, all reception channel bands can be set not to include harmonic frequencies, but in full segment broadcasting, it is difficult to set all reception channel bands not to include harmonic frequencies. is there. Specifically, in one-segment broadcasting, only one of the 13 areas is used, the bandwidth used for each reception channel is as narrow as 0.43 MHz, and each channel is discrete every 6 MHz. For this reason, it is possible to set the LCD operation clock so that the frequency of the harmonics is not included in the band of each reception channel. On the other hand, since all areas are used in full-segment broadcasting, the LCD operation clock cannot be set so that harmonic frequencies are not included in all reception channels. For this reason, a harmonic frequency is included in the band of any one of the reception channels used in terrestrial digital broadcasting.

  The reception channel that includes the harmonic frequency in the band displays the reception channel when the display quality of the reception channel deteriorates due to the interference between the harmonic wave and the broadcast wave of the reception channel and the deterioration of the S / N ratio. There are cases where it is not possible.

JP 2001-077712 A

  However, there is a problem that deterioration of the S / N ratio of the viewing channel due to the harmonic frequency cannot be avoided.

  When the harmonics of unwanted radiation generated in the equipment are included in the band of the reception channel, the unwanted radiation mixed into the antenna can be reduced by increasing the distance between the flexible cable that is the source of unwanted radiation and the antenna. , Noise can be reduced. However, in a small communication terminal such as a mobile phone, it is difficult to ensure a sufficient distance between the flexible cable and the antenna.

  On the other hand, if a shield is formed by surrounding a flexible cable, which is a source of unwanted radiation, with a sheet metal, unwanted radiation mixed into the antenna can be reduced. However, a relatively soft material is used for the flexible cable, and there are cases where a complicated route is taken by bypassing a part between the LCD panel and the processor. In this case, it is difficult to sufficiently shield the flexible cable with a sheet metal.

  In one aspect, an object of the present invention is to provide a broadcast receiving apparatus, a broadcast receiving method, and a broadcast receiving program capable of avoiding deterioration of the S / N ratio of a viewing channel due to harmonic frequencies.

In the first plan, the broadcast receiving apparatus includes a storage area and a processor. The storage area holds a deteriorated channel list including each deteriorated channel that deteriorates due to radiation for each transmission clock. The processor determines whether or not the band of the designated channel is included in the frequency of radiation generated when a signal is transmitted to the display device with the first transmission clock. Further, the processor switches the first transmission clock to the second transmission clock when the band of the designated channel is included in the radiation frequency. Furthermore, the processor sets a transmission clock having a smaller number of degraded channels as a main transmission clock based on the degraded channel list.

  According to one embodiment of the present invention, it is possible to avoid the deterioration of the S / N ratio of the viewing channel due to the harmonic frequency.

FIG. 1 is a block diagram showing a configuration of a broadcast receiving apparatus according to this embodiment. FIG. 2 is a diagram for explaining the regional channel list. FIG. 3 is a diagram for explaining the deteriorated channel list. FIG. 4 is a diagram showing a degraded channel in which the S / N ratio deteriorates due to each harmonic of unnecessary radiation generated when the LCD operation clock is 450 MHz. FIG. 5 is a diagram showing a degraded channel in which the S / N ratio deteriorates due to each harmonic of unnecessary radiation generated when the LCD operation clock is 460 MHz. FIG. 6 is a flowchart for explaining the flow of processing when a reception channel is designated. FIG. 7 is a diagram for explaining a channel scanning method according to this embodiment. FIG. 8 is a flowchart for explaining the flow of channel scan processing according to this embodiment.

  Embodiments of a broadcast receiving apparatus, a broadcast receiving method, and a broadcast receiving program disclosed in the present application will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. Each embodiment can be appropriately combined within a range in which processing contents do not contradict each other.

  An example of a functional configuration of the broadcast receiving apparatus according to the first embodiment will be described. FIG. 1 is a block diagram showing a configuration of a broadcast receiving apparatus according to this embodiment. As shown in FIG. 1, the broadcast receiving apparatus 10 has a substrate 100. An antenna 110 is connected to the substrate 100 via a connector 103, a display device 130 is connected via a flexible cable 131 connected to the connector 104, and an input device 120 via a flexible cable 121 connected to the connector 105. Is connected. The display device 130 is an LCD display panel or the like that displays a reception channel. The input device 120 is an input device such as a touch panel, a keyboard, and a mouse. For example, a reception channel to be displayed on the display device 130 can be specified by operating the touch panel.

  The substrate 100 includes a receiving circuit 101, a memory 102, and a processor 110. The processor 110 includes an input unit 111, a CPU 112, and an output unit 113. Note that data is transmitted / received among the input unit 111, the CPU 112, the output unit 113, and the memory 102 via a bus 114 installed in the processor 110.

(Processing of the entire broadcast receiving device)
The antenna 110 receives terrestrial digital broadcasting from a master station or a relay station. The antenna 110 may be built in the broadcast receiving apparatus or exposed to the outside. The antenna 110 transmits the received broadcast wave to the receiving circuit 101 inside the substrate 100 via the connector 103.

  The receiving circuit 101 converts the received wave in the entire band into received data centered on the broadcast wave corresponding to a predetermined channel group. Then, the reception circuit 101 transmits the reception data related to the designated channel selected by the input device 120 among the generated reception data to the input unit 111.

  Processing until the reception circuit 101 transmits reception data related to the designated channel to the input unit 111 will be described. The input device 120 receives an operation for designating a reception channel, and transmits the designated channel to the CPU 112 via the flexible cable 121. The CPU 112 transmits a signal designating the band of the designated channel to the receiving circuit 101, and the receiving circuit 101 sends the reception data corresponding to the designated channel to the input unit 111.

  The input unit 111 that has received the reception data transmits the reception data to the CPU 112 via the bus 114. At this time, the CPU 112 refers to the deteriorated channel list in the memory 102. When the designated channel corresponds to the deteriorated channel, the CPU 112 transmits an LCD operation clock switching command to the output unit 113 to switch to another LCD operation clock. The setting of the deteriorated channel list and the switching of the LCD operation clock will be described later.

  Next, the CPU 112 generates a video signal based on the received data, and transmits the video signal to the output unit 113 via the bus 114. The output unit 113 transmits a video signal to the display device 130 with a predetermined LCD operation clock via the flexible cable 131. When the output unit 113 receives an LCD operation clock switching command from the CPU 112, the output unit 113 uses another LCD operation clock when transmitting a video signal. Then, the display device 130 displays the video of the designated channel on the screen based on the received video signal.

(Deterioration channel list setting)
The memory 102 holds a regional channel list 301 and a degraded channel list 302. The memory 110 corresponds to, for example, a semiconductor memory device such as a random access memory (RAM), a read only memory (ROM), or a flash memory, and a storage device such as a hard disk or an optical disk.

  The configuration of the regional channel list 301 and the deteriorated channel list 302 will be described with reference to FIGS. FIG. 2 is a diagram for explaining the regional channel list 301. The band used in terrestrial digital broadcasting is 470 MHz to 710 MHz. Each channel is assigned a band of 6 MHz, and the total number of terrestrial digital broadcast channels is 40. Since the channels that can be viewed for each region are different, the memory 102 holds a region channel list 301 that lists receivable channels for each region. For example, as shown in FIG. 2, the memory 102 holds a regional channel list 301 of regions a and b where the receivable channels are different, and the receivable channels are different in each region.

  FIG. 3 is a diagram for explaining the degraded channel list 302. As shown in FIG. 3, the degraded channel list 302 is a list of degraded channels for each setting of the LCD operation clock. For example, when the LCD operation clock is set to 450 MHz, 14ch is included in the degraded channel, but 15ch is not included in the degraded channel. On the other hand, when the LCD operation clock is 460 MHz setting B, 14ch is not included in the deteriorated channel, but 15ch is included in the deteriorated channel. Therefore, the output unit 113 transmits a video signal with an LCD operation clock of 460 MHz when 14ch is designated as a reception channel, and transmits a video signal with an LCD operation clock of 450 MHz when 15ch is designated as a reception channel. . As a result, it is possible to avoid deterioration of the S / N ratio of the reception channel due to generation of unnecessary radiation.

  Next, the relationship between each harmonic of unwanted radiation and the band of the reception channel will be described with reference to FIGS. FIG. 4 is a diagram showing a degraded channel in which the S / N ratio deteriorates due to each harmonic of unnecessary radiation generated when the LCD operation clock is 450 MHz. The antenna 110 receives unnecessary radiation generated by the flexible cable 131 when the output unit 113 transmits a video signal to the display device 130. The frequency of each order harmonic related to unwanted radiation such as n-order, n + 1-order, n + second-order, etc. shown in FIG. 4 can be calculated from the LCD operation clock. The broadcast receiving apparatus 10 extracts a degraded channel based on the harmonic frequency of each order and the band of each reception channel. The memory 102 lists each extracted deteriorated channel for each LCD operation clock and holds it in the deteriorated channel list 302. Details of the calculation of the harmonic frequency and the identification of the deteriorated channel will be described later.

  For example, as shown in FIG. 4, when the LCD operation clock transmitted to the display unit 130 is 450 MHz, the frequency of each harmonic is a band of 14ch for the nth order harmonic and a band of 17ch for the n + 1st order harmonic. N + 2 order harmonics are included in the 20ch band. The S / N ratio of the reception channel is deteriorated by including higher-order harmonics in a band such as 14ch. The broadcast receiving apparatus 10 stores in the memory 102 a list of degraded channels such as 14ch in the degraded channel list 302 of FIG. 3 in association with the setting A of the LCD operation clock. Thereby, the broadcast receiving apparatus 10 can grasp the reception channel for switching the LCD operation clock.

  When receiving the one-segment broadcasting, the receiving circuit 101 has a narrow bandwidth for each channel in the reception band 203a of the one-segment broadcasting and a large unused bandwidth as shown in FIG. For this reason, even if the reception circuit 101 includes harmonics in the reception band 203a of the one-segment broadcasting, if the LCD operation clock is changed, the S / N ratio of the reception channel deteriorates due to the harmonics. Can be avoided. The details of the channel scanning method using the one-segment broadcasting reception function will be described later.

  FIG. 5 is a diagram showing a degraded channel in which the S / N ratio deteriorates due to each harmonic of unnecessary radiation generated when the LCD operation clock is 460 MHz. As shown in FIG. 5, when the LCD operation clock transmitted to the display device 130 is 460 MHz, the nth-order harmonic is included in the 15ch band, and the n + 1st-order harmonic is included in the 19ch band. For this reason, the S / N ratio of a reception channel in which harmonics are included in a band such as 15ch deteriorates. The broadcast receiving apparatus 10 stores a list of degraded channels such as 15ch in the degraded channel list 302 of FIG. 3 in the memory 102 in association with the setting B of the LCD operation clock. Thereby, the broadcast receiving apparatus 10 can grasp the reception channel for switching the LCD operation clock.

  Next, a method for determining a deteriorated channel corresponding to each LCD operation clock will be described. First, the frequency of each harmonic included in unnecessary radiation is calculated. The frequency of each harmonic included in the unwanted radiation can be calculated by the following equation (1), where L is the LCD clock frequency, X is the nth harmonic frequency, and n is the harmonic order.

  X = L / 12 × n (1)

  Next, the upper and lower frequency limits of the band of each reception channel are calculated. When Yh is the upper limit of the band of the receiving channel, Yl is the lower limit of the band of the receiving channel, and C is the number of the receiving channel, the upper limit of the band of the receiving channel is Equation (2), and the lower limit of the band of the receiving channel is Equation (3) ).

  Yh = 476.143 [MHz] +6 [MHz] × (C-13) (2)

  Yl = 470.143 [MHz] +6 [MHz] × (C-13) (3)

  Next, each degradation channel, which is each reception channel including the harmonic frequency, is determined. From the above equations (1) to (3), the frequency of each harmonic and the upper limit value and lower limit value of each reception channel are calculated. If X is the frequency of the nth harmonic, Yh is the upper limit of the band of the receiving channel, and Yl is the lower limit of the receiving channel, whether or not the receiving channel includes the harmonic frequency is determined by the following equation (4). can do.

  Yl ≤ n ≤ Yh (4)

  In addition, since each harmonic has a base around the peak, it may be determined whether or not a harmonic is included in the band of the reception channel in consideration of the width of the base. When the width of the base is r, it can be determined whether or not the reception channel includes a harmonic frequency by the following equation (5).

  (Yl−r) ≦ n ≦ (Yh + r) (5)

(Processing flow when receiving channel is specified)
Next, processing until the broadcast receiving apparatus 10 switches the LCD operation clock when the reception channel is designated will be described with reference to FIG. FIG. 6 is a flowchart for explaining the flow of processing when a reception channel is designated. As shown in FIG. 6, the CPU 112 determines whether or not the currently used LCD operation clock is the setting A (step S10). When the LCD operation clock is set to A (Yes in step S10), the CPU 112 refers to the deteriorated channel list 302 in the memory 102 and determines whether or not the designated channel corresponds to the deteriorated channel related to the setting A (step S11). ). When the designated channel corresponds to the deteriorated channel (Yes in step S11), the CPU 112 switches the setting of the LCD operation clock from setting A to setting B by transmitting an LCD operation clock switching command to the output unit 113 (step S12). On the other hand, when the designated channel does not correspond to the degraded channel (No in step S11), the CPU 112 proceeds to step S13 without switching the setting of the LCD operation clock. Then, the CPU 112 notifies the reception circuit 101 of the designated channel, the reception circuit 101 transmits reception data related to the designated channel, and the CPU 112 generates a video signal based on the reception data and transmits it to the output unit 113. . The output unit 113 transmits the video signal to the display device 130 via the flexible cable 131 at the set LCD clock frequency. Thereby, the broadcast receiving apparatus 10 switches a receiving channel to a designated channel (step S13).

  On the other hand, if the setting of the LCD operation clock is not the setting A in Step S10 (No in Step S10), the CPU 112 determines that the setting is B. Next, the CPU 112 refers to the deteriorated channel list 302 of the memory 102 and determines whether or not the designated channel corresponds to the deteriorated channel according to the setting B (step S14). When the designated channel corresponds to the degraded channel (Yes in step S14), the CPU 112 transmits the LCD operation clock switching command to the output unit 113, thereby switching the setting of the LCD operation clock from the setting B to the setting A (step S15). On the other hand, when the designated channel does not correspond to the deteriorated channel (No in step S14), the CPU 112 proceeds to step S13 without switching the LCD operation clock. Next, the broadcast receiving device 10 transmits the video signal related to the designated channel to the display device by the processing procedure described above, and switches the receiving channel to the designated channel (step S13).

  As described above, the broadcast receiving apparatus 10 includes the processor 110, and the processor 110 includes the band of the designated channel included in the frequency of radiation generated when a signal is transmitted to the display apparatus 130 using the first transmission clock. Determine whether or not. Further, the processor 110 switches the first transmission clock to the second transmission clock when the band of the designated channel is included in the radiation frequency. Thereby, there is an effect that the deterioration of the S / N ratio of the viewing channel due to the harmonic frequency can be avoided.

(Channel scan method)
Radio towers that transmit digital terrestrial broadcast waves over a wide area, such as Tokyo Tower and Sky Tree, are called parent stations, and these parent stations distribute digital terrestrial broadcasts to more than 50% of the regions. On the other hand, in areas where the surrounding area is surrounded by mountains, such as basin areas, the broadcast waves from the master station are blocked by the mountains, and the antennas installed in the area cannot receive the broadcast waves from the master station There is. Therefore, in the area, a relay station is installed separately from the master station, and each residence receives terrestrial digital broadcasts having the same contents as the master station from the relay station. When the relay station transmits a broadcast wave related to the same channel as the parent station, the relay station transmits a broadcast wave of a different band in order to avoid interference with the broadcast wave of the parent station. This avoids a decrease in the S / N ratio of the receiving channel.

  However, when receiving a broadcast wave from the relay station, the broadcast receiving apparatus 10 cannot use the regional channel list 301 because each reception channel uses a band different from the master station. Therefore, the broadcast receiving apparatus 10 performs a channel scan, creates an original channel list 303, and uses it when receiving a broadcast wave from a relay station. Channel scanning refers to checking whether each reception channel used in terrestrial digital broadcasting is actually viewable. The broadcast receiving apparatus 10 checks in advance whether or not each reception channel can be viewed by channel scanning, and registers the channels that can be received in the original channel list 303.

  Specifically, the broadcast receiving apparatus 10 may perform channel scanning according to the following procedure. First, the CPU 112 of the broadcast receiving apparatus 10 transmits a channel scan command to the reception circuit 101, and the reception circuit 101 transmits reception data of each reception channel to the input unit 111. The input unit 111 determines whether or not the reception channel is used in the area by the CPU 112. When the CPU 112 determines that the reception channel is used, the CPU 112 registers the reception channel in the original channel list 303.

  However, when performing channel scanning, there is a problem that unnecessary radiation interferes with determining whether or not each reception channel is viewable. As described above, when the output unit 113 transmits a video signal to the display device 130, unnecessary radiation occurs, and the antenna 110 receives the unnecessary radiation. The unnecessary radiation includes a plurality of harmonics, and when the band of the reception channel includes a harmonic frequency, the S / N ratio of the reception channel deteriorates and becomes a deteriorated channel. When the degraded channel is designated by the channel scan, the CPU 112 may erroneously determine that the reception channel related to the degraded channel is not used because the degraded channel includes noise.

  Therefore, the broadcast receiving apparatus 10 refers to the deteriorated channel list 302 and first scans channels other than the deteriorated channels, and then switches to another LCD operation clock frequency and scans the deteriorated channels. Thereby, it is possible to avoid unnecessary radiation from interfering with channel scanning.

  A channel scanning method will be described with a specific example. FIG. 7 is a diagram for explaining a channel scanning method according to this embodiment. First, the CPU 112 confirms the current setting of the LCD operation clock. Next, the CPU 112 refers to the deteriorated channel list 302 of the memory 102 and confirms the deteriorated channel related to the current setting of the LCD operation clock. According to FIG. 7, the deteriorated channels of the reception band 212a according to the LCD operation clock setting A are 14ch, 17ch, and 20ch.

  Next, the CPU 112 designates a band corresponding to 13ch, 15ch, 16ch, etc., which are reception channels other than the deteriorated channel, and notifies the reception circuit 101 of the designated band. The receiving circuit 101 inputs received data related to the notified band to the input unit 111. The input unit 111 transmits received data to the CPU 112 via the bus 114. Then, the CPU 112 checks whether or not the designated band is used for the reception channel based on the reception data, thereby determining whether or not the reception data related to the band is used for the reception channel. When the CPU 112 determines that the designated band is used for the reception channel, the CPU 112 accesses the memory 102 and registers the reception channel in the original channel list 303.

  The broadcast receiving apparatus 10 creates the original channel list 303 by repeating the above operation for reception channels other than the other deteriorated channels. The CPU 112 registers all received channels other than the deteriorated channel in the original channel list 303, and then transmits an LCD operation clock switching signal to the output unit 113. The CPU 112 specifies a band related to the degraded channel, and the receiving circuit 101 inputs received data related to the band to the input unit 111. Thereafter, the broadcast receiving apparatus 10 performs a channel scan on the deteriorated channel in the same manner as described above, and registers all received channels in the original channel list 303.

(Channel scan processing flow)
Next, a channel scan processing procedure will be described with reference to FIG. FIG. 8 is a flowchart for explaining the flow of channel scan processing in this embodiment. As shown in FIG. 8, the CPU 112 determines whether or not the setting of the LCD operation clock used to transmit the video signal from the output unit 113 is A (step S20). When the setting of the LCD operation clock is not A (step S20 No), the CPU 112 switches the setting of the LCD operation clock to A (step S21). On the other hand, when the setting of the LCD operation clock is A (Yes in step S20), the CPU 112 proceeds to step S22 without switching the LCD operation clock.

  Next, the broadcast receiving apparatus 10 scans other than the deteriorated channel when the setting of the LCD operation clock is A (step S22). Specifically, the CPU 112 notifies the reception circuit 101 of reception channels other than the deteriorated channel. The reception circuit 101 transmits reception data related to the notified band of the reception channel to the input unit 111 of the processor 110, and the input unit 111 transmits the reception data to the CPU 112. When the CPU 112 determines that the band is used for the reception channel based on the reception data, the CPU 112 registers the reception channel in the original channel list 303.

  After the broadcast receiving apparatus 10 scans all channels other than the deteriorated channels, the CPU 112 transmits an LCD operation clock switching command to the output unit 113, and changes the setting of the LCD operation clock to B (step S23). Next, the broadcast receiving apparatus 10 scans all the degraded channels for which channel scanning has been reserved in the same manner as described above (step S24).

(Create degraded channel list)
When receiving the terrestrial digital broadcast from the master station, the broadcast receiver 10 relates to the broadcast receiver 10 if the band of the broadcast wave from the master station is compared with the harmonic frequency of each setting of the LCD operation clock. The degradation channel list 302 can be created in advance before the product is shipped. On the other hand, when receiving the terrestrial digital broadcast from the relay station, the broadcast receiving apparatus 10 cannot create the deteriorated channel list 302 before shipping the product because the band used by each reception channel is unknown. Therefore, the broadcast receiving apparatus 10 may create a degraded channel list 302 corresponding to the original channel list 303 when performing a channel scan.

  Specifically, the CPU 112 calculates the frequency of each harmonic by substituting the current LCD operation clock into equation (1). The CPU 112 refers to the original channel list 303 and selects a reception channel that includes the calculated frequency of each harmonic in the use band. Then, the CPU 112 registers the selected reception channel in the degradation channel list 302. Thereby, the broadcast receiving apparatus 10 can create the degraded channel list 302 corresponding to the original channel list 303.

(High speed channel scan)
In the channel scan described above, the LCD operation clock is switched. However, since it takes time to switch the LCD operation clock, the channel scan also takes a considerable time. Therefore, when the broadcast receiving apparatus 10 has a function of receiving one-segment broadcasting other than full-segment broadcasting, the channel scanning may be performed using the function.

  An operation for channel scanning using the function of receiving one-segment broadcasting will be described. The CPU 112 notifies the receiving circuit 101 of the band related to the one-segment broadcasting channel, and the receiving circuit 101 transmits the received data related to the notified band to the input unit 111. The input unit 111 transmits received data to the CPU 112 via the bus 114. The CPU 112 determines whether received data related to the band is used for one-segment broadcasting. If the CPU 112 determines that the channel is being used, the CPU 112 obtains the reception band of the corresponding full-segment broadcasting channel based on the reception band associated with the one-segment broadcasting channel and registers it in the original channel list 303 of the memory 102. Note that all the channels are used for each channel related to full-segment broadcasting of terrestrial digital broadcasting. On the other hand, each channel related to one-segment broadcasting uses only one area in the center out of 13 areas. For this reason, if the reception band of one-segment broadcasting is known, the reception band of full-segment broadcasting can be obtained from the reception band.

(Action to be taken when LCD drawing is stopped when switching the LCD operating clock)
When the CPU 112 switches the LCD operation clock, video transmission from the output unit 113 to the display device 130 is stopped. Then, after switching the LCD operation clock, the CPU 112 resumes video transmission to the display device 130. Therefore, when the CPU 112 switches the LCD operation clock, the screen of the display device 130 becomes a black screen until the video transmission is resumed.

  By the way, the LCD operation clock switching command is issued by making an interrupt request to the CPU. For this reason, when a number of high priority interrupt requests have already been made to the CPU, the CPU 112 switches the LCD operation clock switching instruction behind the queue. May take up to 6 seconds.

  Therefore, the broadcast receiving apparatus 10 may set the LCD operation clock with a small number of deteriorated channels as the main setting. Thereby, the broadcast receiving apparatus 10 can reduce the number of times of switching of the LCD operation clock, and can reduce the stop of the video when the channel is switched. Specifically, in order to select an LCD operation clock with a small number of deteriorated channels, the broadcast receiving apparatus 10 may refer to the deteriorated channel list 302 and set the LCD operation clock with the least deteriorated channels as a main setting.

  The total number of terrestrial digital broadcasting channels is 40, but not all channels are used in one region, and the channels used differ depending on the region. Therefore, the broadcast receiving apparatus may select an LCD clock setting with a small number of deteriorated channels for each regional channel list 301 and select a main setting for the LCD operation clock for each regional channel list 301.

  In addition, when the CPU 112 switches the LCD operation clock, a still image related to the image displayed on the display device 130 immediately before may be displayed. For this purpose, the broadcast receiving device 10 periodically installs still images related to the video currently displayed on the display device 130 on the display unit 130 side based on the video signal transmitted from the output unit 113. Store in buffer. Then, the broadcast receiving device 10 may display the still image on the display device 130 when switching the LCD operation clock. Thereby, it can avoid that a video stops and it becomes a black screen.

  The following supplementary notes are further disclosed with respect to the embodiments including the above examples.

(Appendix 1) It is determined whether or not the band of the designated channel is included in the frequency of radiation generated when a signal is transmitted to the display device with the first transmission clock,
A processor that switches the first transmission clock to a second transmission clock when the band of the designated channel is included in the radiation frequency;
A broadcast receiving apparatus comprising:

(Supplementary note 2) For each transmission clock, further comprises a storage area for holding a deteriorated channel list including each deteriorated channel deteriorated by radiation,
The processor identifies a reception channel including the frequency of the radiation based on the degraded channel list;
The broadcast receiving apparatus according to appendix 1.

(Supplementary note 3) The storage area holds the band of each reception channel,
The processor calculates the frequency of each harmonic corresponding to radiation;
Each receiving channel that includes the frequency of each of the harmonics in a band is determined,
Create a degraded channel list based on the judgment results,
The broadcast receiving device according to attachment 2.

(Supplementary Note 4) The processor refers to the degraded channel list, scans a reception channel other than the degraded channel with the first transmission clock, and
The processor selects a second transmission clock that does not include each degraded channel related to the first operation clock;
A channel scan is performed by scanning a deteriorated channel related to the first transmission clock with the second transmission clock.
The broadcast receiving apparatus according to appendix 3.

(Appendix 5) A broadcast receiving method executed by a computer,
Determining whether the band of the designated channel is included in the frequency of radiation generated when a signal is transmitted to the display device with the first transmission clock;
When the band of the designated channel is included in the radiation frequency, the first transmission clock is switched to the second transmission clock.
Broadcast receiving method for executing processing.

(Appendix 6)
Determining whether the band of the designated channel is included in the frequency of radiation generated when a signal is transmitted to the display device with the first transmission clock;
When the band of the designated channel is included in the radiation frequency, the first transmission clock is switched to the second transmission clock.
A broadcast reception program for executing processing.

DESCRIPTION OF SYMBOLS 10 Broadcast receiving apparatus 100 Board | substrate 101 Reception circuit 102 Memory 103 Connector 104 Connector 105 Connector 110 Processor 111 Input part 112 CPU
113 Output unit 120 Input device 130 Display device

Claims (6)

Determining whether the band of the designated channel is included in the frequency of radiation generated when a signal is transmitted to the display device with the first transmission clock;
A processor that switches the first transmission clock to a second transmission clock when a band of the designated channel is included in the radiation frequency ;
A storage area for holding a deteriorated channel list including each deteriorated channel deteriorated by radiation for each transmission clock, and
The broadcast receiving apparatus , wherein the processor sets a transmission clock having a smaller number of degraded channels as a main transmission clock based on the degraded channel list . The processor identifies a designated channel including the frequency of the radiation based on the degraded channel list;
The broadcast receiving apparatus according to claim 1. The storage area holds the band of each reception channel,
The processor calculates the frequency of each harmonic corresponding to radiation;
Each receiving channel that includes the frequency of each of the harmonics in a band is determined,
Create a degraded channel list based on the judgment results,
The broadcast receiving apparatus according to claim 1 . The processor refers to the degraded channel list, scans a received channel other than the degraded channel with a first transmission clock,
The processor selects a second transmission clock that does not include each degraded channel related to the first operation clock;
A channel scan is performed by scanning a deteriorated channel related to the first transmission clock with the second transmission clock.
The broadcast receiving apparatus according to claim 3. A broadcast reception method executed by a computer,
Determining whether the band of the designated channel is included in the frequency of radiation generated when a signal is transmitted to the display device with the first transmission clock;
When the bandwidth of the specified channel is included in the frequency of the radiation, it switches the first transmission clock to the second transmission clock,
For each transmission clock held in the storage area, a transmission clock with a smaller number of degraded channels is set as the main transmission clock based on a degraded channel list including each degraded channel that deteriorates due to radiation.
Broadcast receiving method for executing processing. On the computer,
Determining whether the band of the designated channel is included in the frequency of radiation generated when a signal is transmitted to the display device with the first transmission clock;
When the bandwidth of the specified channel is included in the frequency of the radiation, it switches the first transmission clock to the second transmission clock,
For each transmission clock held in the storage area, a transmission clock with a smaller number of degraded channels is set as the main transmission clock based on a degraded channel list including each degraded channel that deteriorates due to radiation.
A broadcast reception program for executing processing.

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