JP3082116U - Television equipment - Google Patents

Abstract

(57) [Summary] (With correction) [Problem] To provide a sensitivity control circuit, the circuit configuration becomes complicated and the manufacturing cost increases. SOLUTION: When performing a preset, a user performs CR.
By appropriately selecting a desired reception sensitivity from the reception sensitivity selection screen 100 displayed at T, a preset based on the selected reception sensitivity can be obtained. At this time, by setting the selectable reception sensitivity in the frequency range α of the horizontal synchronization signal, a user who does not want to preset the screen mixed with noise has a low
The user who wants to preset all broadcast signals by selecting the W setting 103 selects the HIGH setting 101 having a wide frequency range α, so that the user can perform a preset setting close to the desired one. In addition, a simple configuration can be realized by executing this processing by the microcomputer.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a television device and an auto search device, and more particularly to a television device and an auto search device capable of changing reception sensitivity when presetting a broadcast signal.

[0002]

[Prior art]

 2. Description of the Related Art Conventionally, as this type of television apparatus, there has been known a television apparatus disclosed in Japanese Patent Application Laid-Open No. H5-275978. According to the publication, when an auto search function is performed in a television device, the sensitivity of the receiver is automatically increased or decreased, so that only the necessary broadcast frequency according to the surrounding radio wave environment is reliably searched and received. A technique for storing data in a memory inside the device is disclosed. At this time, the television apparatus is provided with an antenna, a high-frequency amplifier, a frequency converter, an intermediate frequency amplifier, a sensitivity control circuit, a demodulator, a local starter, and a microcomputer. Then, first, the signal received by the antenna is amplified by the high-frequency amplifier and output to the sensitivity control circuit. Here, the sensitivity of the sensitivity control circuit is changed and controlled by a sensitivity control signal from the microcomputer. The signal whose level has been adjusted by the sensitivity control circuit is output to a demodulation unit, where the signal is demodulated into a video signal and an audio signal to enable viewing. Further, as a similar technique, one disclosed in Japanese Patent Application Laid-Open No. 1-341010 is known. This publication discloses a technique related to a radio receiver capable of automatically presetting a predetermined number of stations having a strong electric field strength by expanding the identification range of the electric field strength.

[0003]

[Problems to be solved by the invention]

 The above-described conventional television apparatus has the following problems. In the former Japanese Patent Application Laid-Open No. Hei 5-275978, it is necessary to provide a sensitivity control circuit, which complicates the circuit configuration and increases the manufacturing cost. Also, if an auto search is performed in a strong radio wave environment, the reception sensitivity is automatically reduced, and it may not be possible to detect the broadcast frequency of a weak input. When a search is performed, the reception sensitivity is automatically increased, so that even unnecessary broadcast frequencies may be detected. On the other hand, the latter JP-A-1-314010 adjusts a preset radio station by controlling the received electric field strength, and does not suggest any television apparatus.

[0004] The present invention has been made in view of the above problems, and it is possible to appropriately change the reception sensitivity when searching for a broadcast frequency with a simple configuration and a simple method, and to search for a desired broadcast frequency. It is an object of the present invention to provide a television device and an automatic search device capable of performing such operations.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the invention according to claim 1 performs an auto search by a microcomputer based on the frequency of a horizontal synchronization signal of a radio wave received by a tuner, stores the detected broadcast frequency in an EEPROM, and presets the broadcast frequency. The television apparatus includes a frequency width setting unit that can select and set the frequency width of the horizontal synchronization signal to be searched for when performing the auto search, and the microcomputer controls the horizontal synchronization signal of the received radio wave. The frequency is calculated, and when the calculated frequency is included in the frequency width set by the frequency width setting unit, the broadcast frequency is detected and stored in the EEPROM.

[0006] In the invention according to claim 1 configured as described above, the microcomputer automatically searches for the broadcast frequency based on the frequency of the horizontal synchronization signal of the radio wave received by the tuner, and stores the detected broadcast frequency in the EEPROM. A television apparatus that presets the horizontal synchronization signal by performing a frequency width setting of the horizontal synchronization signal to be selected when the automatic search is performed, and a microcomputer that controls the horizontal synchronization signal of the received radio wave. The broadcast frequency is calculated, and when the calculated frequency is included in the frequency width set by the frequency width setting unit, the broadcast frequency is detected and stored in the EEPROM.

With the configuration described above, it is possible to provide a television device as a specific device capable of detecting a broadcast frequency from a received radio wave based on a reception sensitivity set by a user. On the other hand, such a technical idea is not limited to a specific device to which the technology is applied, but can also be realized as an auto search device that detects a broadcast frequency from a received radio wave based on a selected and set reception sensitivity. Needless to say.

Therefore, the present invention provides a tuner for receiving radio waves at a set receiving frequency, a receiving sensitivity setting means for selecting and setting a receiving sensitivity when executing an auto search, and a tuner for the tuner. The reception frequency is sequentially changed and set, and it is determined whether the radio wave received by the tuner is equal to or higher than the reception sensitivity while maintaining the reception sensitivity set by the reception sensitivity setting means, and Search control means for detecting a broadcast frequency when the received radio wave has the same or higher sensitivity is provided. In the invention according to claim 2 configured as described above, the tuner receives radio waves at the reception frequency set by the search control means. When executing the auto search, the reception sensitivity can be selected and set by the reception sensitivity setting means. Here, as described above, the search control means sets the tuner to sequentially change the reception frequency while receiving the radio wave, and the radio wave received by the tuner is received by the reception sensitivity setting means. It is determined whether the sensitivity is equal to or higher than the sensitivity. Then, if the received radio wave is at or above this reception sensitivity, the broadcast frequency is detected.

[0009] As an example of a method for detecting the presence or absence of a broadcast frequency by a search control means, the invention according to claim 3 is based on the auto search apparatus according to claim 2, wherein two numerical data having different reception sensitivities are used. And the search control means includes frequency calculation means for calculating a frequency of a predetermined synchronization signal of the received radio wave. When the calculated frequency falls between the two numerical data, It is configured to detect the broadcast frequency. In the invention according to claim 3 configured as described above, the receiving sensitivity is configured by two different numerical data. Then, the search control means is provided with a frequency calculating means for calculating the frequency of the predetermined synchronization signal. With such a configuration, the search control means determines the presence or absence of the broadcast frequency, and determines that the broadcast frequency is present when the frequency calculated by the frequency calculation means falls between two numerical data constituting the reception sensitivity. The broadcast frequency is detected from the received radio wave.

As a preferred example of the above-described search control means adopted as a synchronization signal for calculating a frequency, the invention according to claim 4 is based on the automatic search device according to claim 3. The means is configured to use a horizontal synchronization signal superimposed on the broadcast frequency as the synchronization signal. In the invention according to claim 4 configured as described above, the frequency of the horizontal synchronization signal superimposed on the broadcast frequency is calculated by the frequency calculation means provided in the search control means. Then, the search control means detects the broadcast frequency when the frequency of the horizontal synchronization signal is included in the range of two numerical data set as the reception sensitivity.

As another preferred example applied to the synchronization signal, the invention according to claim 5 is directed to an auto search apparatus according to claim 3, wherein the search control means includes the synchronization signal as the synchronization signal. The configuration uses a vertical synchronization signal superimposed on the broadcast frequency. In the invention according to claim 5 configured as described above, the frequency of the vertical synchronization signal superimposed on the broadcast frequency is calculated by the frequency calculation means provided in the search control means. Then, the search control means determines that there is a broadcast frequency when the frequency of the vertical synchronization signal is included in the range of two numerical data set as the reception sensitivity.

As described above, the reception sensitivity is selected and set within a predetermined range. Here, it is preferable that the set range of the receiving sensitivity can be appropriately changed. Therefore, the invention according to claim 6 is the auto search apparatus according to any one of claims 2 to 5, wherein the reception sensitivity setting means is capable of changing a range of the set reception sensitivity. It has a configuration having a changing means. In the invention according to claim 6 configured as described above, the receiving sensitivity setting means is provided with the receiving sensitivity changing means. Then, the range of the receiving sensitivity set and selected in the predetermined range by the receiving sensitivity changing means can be changed.

It is preferable that the search sensitivity can be automatically changed by the search control means in accordance with the state of the broadcast frequency. Therefore, the invention according to claim 7 is directed to an auto search apparatus according to any one of claims 2 to 6, wherein the search control means changes the reception sensitivity based on the detected broadcast frequency. is there. In the invention according to claim 7 configured as described above, the search control means changes the receiving sensitivity based on the detected broadcast frequency. Then, the presence or absence of a broadcast frequency is determined based on the changed reception sensitivity.

[0014] As an example of a situation where the reception sensitivity is changed by the search control means, the invention according to claim 8 is directed to the auto search apparatus according to claim 7, wherein the search control means comprises: Is larger than a predetermined threshold value, the receiving sensitivity is changed in a direction in which the number of detected broadcast frequencies decreases. In the invention according to claim 8 configured as described above, the search control means determines whether or not the number of broadcast frequency detections is greater than a predetermined threshold value. If it is larger, change the reception sensitivity in the direction that the number of detections of the same broadcast frequency decreases.

[0015] As another example of a situation where the reception sensitivity is changed by the search control means, the invention according to claim 9 is directed to the auto search apparatus according to claim 7, wherein the search control means is adapted to control the broadcast frequency. When the number of detections is smaller than a predetermined threshold, the reception sensitivity is changed in a direction to increase the number of detections of the broadcast frequency. In the invention according to claim 9 configured as described above, the search control means determines whether or not the number of broadcast frequency detections is greater than a predetermined threshold, and determines whether the number of broadcast frequency detections is a predetermined threshold. When the value is smaller than the value, the receiving sensitivity is changed in a direction to increase the number of detections of the same broadcast frequency. The predetermined threshold value is not particularly limited, and may be the number of detections of a desired broadcast signal by the user or may be a preset value.

[0016]

[Effect of the invention]

 As described above, the present invention enables the microcomputer to detect and preset the broadcast frequency based on the set frequency width of the horizontal synchronization signal, so that the configuration can be simplified and utilized. By appropriately setting the frequency width of the horizontal synchronization signal in accordance with the usage pattern of the user, it is possible to provide a television device capable of presetting a desired broadcast frequency. Further, according to the invention of claim 2, it is possible to detect a broadcast frequency based on a desired reception sensitivity by enabling a search for a broadcast frequency while maintaining the reception sensitivity appropriately selected and set. A simple auto search device can be provided. Further, according to the invention of claim 3, it can be shown as an example of a method for detecting the presence or absence of a broadcast frequency in the search control means. Further, according to the invention of claim 4, it is possible to show a preferred example which is adopted for a synchronization signal. Further, according to the invention of claim 5, another example suitable for use in a synchronization signal can be shown.

Further, according to the invention of claim 6, it becomes possible to appropriately change and set the receiving sensitivity according to the user's preference. Furthermore, according to the invention of claim 7, since the receiving sensitivity can be automatically changed and set according to the detection state of the broadcast frequency, the detection of the broadcast frequency increases as the number of detections decreases. The reception sensitivity can be changed and set at the same time, and the reception sensitivity can be changed and set so that the detection of the broadcast frequency decreases as the number of detections increases. Further, according to the inventions according to claims 8 and 9, it is possible to detect a desired number of broadcast frequencies by appropriately changing the reception sensitivity according to the number of broadcast frequencies detected.

[0018]

[Embodiment of the invention]

 Here, embodiments of the present invention will be described in the following order. (1) About the outline of the invention: (2) About the configuration of the television device: (3) About the embodiment: (4) About the modification: (5) Summary: Hereinafter, an embodiment of the invention will be described with reference to the drawings. I do.

(1) Concept of Invention: FIG. 1 is a schematic diagram showing a technical outline of an auto search device according to the present invention. Referring to FIG. 1, an auto search device C according to the present invention includes a tuner C1, a reception sensitivity setting unit C2, and a search control unit C3. Tuner C1 receives radio waves at the set frequency. The receiving sensitivity setting means C2 can select and set the above receiving sensitivity within a predetermined range. The search control means C3 determines whether the radio wave received by the tuner C1 is equal to or higher than the set reception sensitivity while sequentially changing the reception frequency with respect to the tuner C1. Then, if the result of the determination indicates that the received radio wave is equal to or higher than the set reception sensitivity, the broadcast frequency is detected.

That is, the tuner C1 receives radio waves based on the reception frequency sequentially changed by the search control means C3, and the search control means C3 detects a broadcast frequency from the radio waves received by the tuner C1. Then, in such a case, the search control means C3 acquires the reception sensitivity selected and set by the reception sensitivity setting means C2, and determines whether or not the received radio wave is at or above this reception sensitivity. Then, when the received radio wave is equal to or higher than the reception sensitivity, the broadcast frequency is detected. In this way, by selecting and setting a desired reception sensitivity by the reception sensitivity setting means C3, it is possible to detect a desired broadcast frequency.

(2) Configuration of Television Device: FIG. 2 is a block diagram showing a main part of a television device provided with an auto search device according to an embodiment of the present invention, and FIG. 3 is a block diagram of a PLL tuner. FIG. 3 is a block diagram showing a configuration. In the figure, an RF signal on which a broadcast signal is superimposed is input to a PLL tuner 10 via an antenna. The input RF signal is amplified by an amplifier 11 and input to a mixing circuit 12. The local oscillation signal f0 output from the voltage controlled oscillator (VCO) 13 is also input to the mixing circuit 12. The mixing circuit 12 outputs a signal representing the difference between the local oscillation signal f0 and the RF signal amplified at a high frequency as an intermediate frequency signal.

The frequency of the local oscillation signal f 0 can be changed by control of the microcomputer 30, and the frequency is stabilized by feedback control. That is, the voltage controlled oscillator 13 includes a resonance circuit (not shown), and the capacitance component forming the resonance circuit is variable depending on the applied voltage. This applied voltage is supplied from the integrating circuit 14, and the voltage controlled oscillator 13 changes the frequency according to this voltage and outputs it as the local oscillation signal f0.

The local oscillation signal f 0 is also input to the variable frequency divider 17. The variable frequency divider 17 is a circuit for dividing the frequency of the input signal, and the frequency division ratio can be changed under the control of the microcomputer 30. Therefore, the microcomputer 30 can change the frequency to be tuned by changing the frequency division ratio, and can grasp the frequency. The output of the variable frequency divider 17 is input to the detection circuit 16 as a divided signal f2. On the other hand, the reference oscillator 15 is a circuit that outputs an oscillation signal from a crystal oscillator or the like via a fixed frequency divider, and its output is input to the detection circuit 16 as a reference signal f1.

The detection circuit 16 is a circuit that performs positive and negative detection outputs according to the phase difference between the two input signals. The detection output is input to the integration circuit 14 so that a DC component is extracted. The minute is input to the voltage controlled oscillator 13. The voltage controlled oscillator 13 oscillates according to the DC component as described above, and controls so that the phase difference between the divided signal f2 and the reference signal f1 converges to "0". That is, the circuit configuration is to feedback control the frequency. Further, in the voltage controlled oscillator 13, it is possible to switch a plurality of circuit configurations to make different resonance circuits effective, and the microcomputer 30 performs switching for each band, thereby controlling transmission and reception signals in a plurality of frequency bands. Tuning operation is possible.

The intermediate frequency signal output from the mixing circuit 12 of the PLL tuner 10 is input to the TVIC 20. The TVIC 20 performs various signal processing such as demodulation of a video signal and an audio signal based on the intermediate frequency signal. The video signal is subjected to video detection after amplifying the input intermediate frequency signal, and is subjected to a predetermined color demodulation process based on the detected output to output an RGB signal. This RGB signal is output to the CRT 40 via a cathode amplifier (not shown). The audio signal is subjected to audio intermediate frequency amplification and then audio detection, and is separated into a main channel audio signal and a sub channel audio signal based on the audio detection output and demodulated. The demodulated signal is output to a speaker (not shown) via a matrix circuit or an amplifier.

The TVIC 20 separates the horizontal and vertical synchronizing signals in addition to such video and audio signals. The TVIC 20 outputs the signals to perform horizontal and vertical driving on the CRT 40, and also detects when the channel selection is completed. For this purpose, the horizontal / vertical synchronization signal (SYNC) is input to a general-purpose port provided in the microcomputer 30. The microcomputer 30 calculates the frequency of the horizontal synchronizing signal input from the general-purpose port and searches for a broadcast signal while judging whether or not there is no video signal.

The microcomputer 30 determines whether there is no video signal or not in this manner, and registers a preset frequency as a center frequency while associating a frequency at which a video signal exists as a broadcast signal with each channel number. Perform the operation. In the present embodiment, tuning is attempted in all the frequency ranges of the VHF Low band, the VHF High band, and the UHF band when presetting. That is, the microcomputer 30 first switches the voltage-controlled oscillator 13 so that the VHF low band can be received. Then, the frequency division ratio of the variable frequency divider 17 is controlled to sequentially change the tuning frequency. As a result, the tuning frequency determined to be a video signal by the horizontal synchronization signal input through the general-purpose port of the microcomputer 30 Is stored in a memory (not shown). Further, the voltage-controlled oscillator 13 is switched to store the tuning frequency in the VHF High band and the UHF band. This storage operation is a preset operation.

Here, the TVIC 20 includes an AFT circuit 21 and uses the preset tuning frequency as a center frequency, and finely adjusts the frequency within a range of ± 2 MHz with respect to the center frequency. Therefore, those within this fine adjustment range should be the same station, and frequencies that are close to this “2 MHz” and within “3 MHz” with some allowance are regarded as the same station. The AFT circuit 21 is a circuit that outputs a predetermined AFT voltage generated by a difference between the frequency of the intermediate frequency signal and the reference frequency. The AFT voltage is input via an A / D input terminal of the microcomputer 30. The microcomputer 30 determines whether the AFT voltage input through the A / D input terminal is at a predetermined reference level, and controls the variable frequency divider 17 of the PLL tuner 10 if the AFT voltage is not at the predetermined reference level. Then, fine adjustment in the range of ± 2 MHz is performed. The TVIC 20 includes an OSD circuit 22. The OSD circuit 22 generates an OSD signal that can configure a predetermined screen display under the control of the microcomputer 30, and can output the OSD signal to the CRT 40 to perform the OSD display. It has become.

The microcomputer 30 executes control operations of various circuits in addition to the above. For example, an input operation performed by the user via the remote controller 50 is received, and a process corresponding to the operation content is executed. That is, when the user performs a button input operation on the remote controller 50, an infrared remote control signal corresponding to the operation content is output, and the infrared remote control signal received by the light receiving unit (not shown) is analyzed by the microcomputer 30. In both cases, operations such as channel up / down and volume up / down are performed according to the operation content. Further, the microcomputer 30 can receive a setting operation performed by the user via the remote controller 50 and store the setting contents in the EEPROM 60. The microcomputer 30 can read out the contents of the setting from the EEPROM 60 and execute a predetermined control process.

(3) Embodiment: The processing operation of the microcomputer 30 is realized by executing each program in a program execution environment including a ROM, an EEPROM 60, and the like (not shown). 4 is a general flowchart showing a schematic processing operation of the microcomputer 30 at the time. In the figure, first, the microcomputer 30 allows the user to select and set the reception sensitivity when detecting a preset broadcast signal (step S100). Next, a preset is executed based on the reception sensitivity selected and set by the user (step S200). As described above, in the present embodiment, it is possible to perform presetting according to the usage status of the user by enabling the above-mentioned search for the broadcast signal based on the reception sensitivity selected and set by the user. .

FIG. 5 shows the screen display of the reception sensitivity selection screen displayed on the CRT 40 by the OSD circuit 22 based on the control of the microcomputer 30 when the user selects and sets the reception sensitivity in step S100 described above. FIG. In the figure, a reception sensitivity selection screen 100 includes a reception sensitivity HIGH setting 101, a NORMAL setting 102, and a LOW setting 103. The user uses the remote controller 50 to select a desired setting from any of the HIGH setting 101, the NORMAL setting 102, and the LOW setting 103. The setting to be selected is highlighted and visible, and in this embodiment, the HIGH setting 101 is selected.

Here, the NORMAL setting 102 has a default setting, and the receiving sensitivity based on the normal setting content can be selected. On the other hand, in the HIGH setting 101, a receiving sensitivity having a wider sensitivity range than the receiving sensitivity set in the NORMAL setting 102 is set, and by selecting the HIGH setting 101, the search is performed in the NORMAL setting 102. More broadcast signals than the number of broadcast signals can be searched. In the LOW setting 103, the receiving sensitivity whose sensitivity range is narrower than the receiving sensitivity set in the NORMAL setting 102 is set. By selecting the LOW setting 103, the search is performed in the NORMAL setting 102. Broadcast signals smaller than the number of broadcast signals can be searched.

Here, the receiving sensitivity will be described. As described above, in the present embodiment, when searching for a broadcast signal, the frequency of the horizontal synchronization signal superimposed on the broadcast signal is used. In the broadcast signal of the NTSC system, the horizontal synchronizing signal is set at a frequency of about 15.734 kHz. Therefore, the microcomputer 30 calculates the frequency of the horizontal synchronization signal input from the general-purpose port, and searches for a broadcast signal if the frequency is approximately 15.734 kHz. FIG. 6 is a diagram showing a frequency range of the horizontal synchronization signal set as the receiving sensitivity. In the figure, the NORMAL setting is set to a frequency range of ± 0.2 kHz around 15.734 kHz, and the HIGH setting is set to a frequency range of ± 0.5 kHz around 15.734 kHz. . Therefore, in the HIGH setting, it is possible to search for a broadcast signal with a weak input, and it is possible to search for more broadcast signals than in the NORMAL setting. On the other hand, the LOW setting is set to a frequency range of ± 0.1 kHz centering on 15.5734 kHz. Therefore, it is possible to search for a broadcast signal with a strong input, and to search for less broadcast signals than the NORMAL setting.

FIG. 7 is a flowchart showing the processing contents of the reception sensitivity selection processing executed by the microcomputer 30 in step S100 described above. In the figure, when the user performs a preset operation by pressing a predetermined button on the remote controller 50, the microcomputer 30 detects this operation and activates the reception sensitivity selection processing. In such a case, first, the OSD circuit 22 is controlled to display the reception sensitivity selection screen 100 shown in FIG. 5 on the CRT 40 (step S105). When the user selects any of the HIGH setting 101, the NORMAL setting 102, or the LOW setting 103 (step S110), the selected reception sensitivity setting is acquired (step S115) and stored in a predetermined area of the EEPROM 60. (Step S120). Thereby, the receiving sensitivity is set, and the microcomputer 30 executes the preset processing based on the receiving sensitivity.

Here, the reception sensitivity may be selected by the user from selection items based on a preset frequency range of the horizontal synchronization signal, or the frequency range may be changed as appropriate according to the user's preference. You may be able to do it. FIG. 8 is a screen diagram showing a display of a reception sensitivity change screen displayed on the CRT 40 by the OSD circuit 22 when the frequency range of the reception sensitivity is changed. In the figure, a reception sensitivity change screen 200 is composed of a HIGH setting change 201, a NORMAL setting change 202, and a LOW setting change 203, and each of the setting changes 201-203 has scale bars 201a-203a and level. Positions 201b to 203b are provided. The user uses the up / down buttons of the remote controller 50 to move the level positions 201b to 203b within the range of the scale bars 201a to 203a as appropriate. When the level positions 201b to 203b are moved in this manner, the frequency range of the horizontal synchronization signal in each setting shown in FIG. 6 is changed. As a result, the user can appropriately change the reception sensitivity to a desired setting.

FIG. 9 is a flowchart showing the contents of the preset processing executed by the microcomputer 30 in step S 200 described above. In the figure, when the reception sensitivity setting process described above is completed, the microcomputer 30 starts the preset process. In such a case, the microcomputer 30 first reads out the reception sensitivity stored in a predetermined area of the EEPROM 60 in step S120 (step S205). Then, it is determined whether or not the reception sensitivity is the NORMAL setting (step S210). If the reception sensitivity is the NORMAL setting, the frequency range α of the horizontal synchronization signal is set to α = (15.734 ± 0.2) kHz. (Step S215). On the other hand, if the setting is not the NORMAL setting, it is determined whether the setting is the HIGH setting (step S220). If the setting is the HIGH setting, the frequency range α of the horizontal synchronizing signal is set to α = (15.734 ± 0.5) kHz. . If the setting is not the HIGH setting, it is determined that the setting is the LOW setting, and the frequency range α is set to α = (15.734 ± 0.1) kHz.

Next, switching of the voltage controlled oscillator 13 is performed so that the VHF Low band can be received (step S 235). Then, the variable frequency divider 17 is controlled to sequentially change the frequency division ratio, and tuning is attempted for all frequencies in the VHF Low band. Then, the frequency β of the horizontal synchronizing signal input through the general-purpose port is calculated (step S240), and whether the video signal exists based on whether this frequency β is included in the set frequency range α or not is determined. It is determined whether or not it is (step S245). If it is determined in step S245 that there is a video signal, a broadcast signal is detected, and the tuning frequency at that time is stored in EEPROM 60 (step S250). Then, it is determined whether or not the scanning has been completed in the entire frequency band of the band set by the switching (step S255), and the determination is made in step S255 until the scanning of the entire frequency band is determined to be completed. The process from step S235 is executed for the band.

Here, when it is determined in step S255 that scanning of all frequency bands has been completed, it is determined whether or not scanning has been performed in all of the VHFLow band, VHFHigh band, and UHF band ( Step S260). If it is not determined in step S260 that scanning has been performed for all bands, the band is switched by controlling the voltage-controlled oscillator 13 (step S265), and the processing from step S235 is repeated. That is, after the scan of the VHFLow band is completed, the band is switched from the VHFLow band to the VHFHigh band, and after the scan of the VHFHigh band is completed, the band is switched from the VHFHigh band to the UHF band. On the other hand, if it is determined in step S260 that scanning has been performed for all bands, the tuning frequency stored in the EEPROM 60 is preset in the EEPROM 60 as a center frequency while corresponding to the channel number in step S250 (step S270). .

(4) Modifications: In the above-described embodiment, a configuration is adopted in which the reception sensitivity to be set is within the frequency range of the horizontal synchronization signal. However, it is needless to say that the reception sensitivity is not limited to the frequency range of the horizontal synchronization signal. Instead, the frequency range of the vertical synchronization signal may be adopted. The present invention is not limited to a configuration in which the user selects the HIGH setting 101, the NORMAL setting 102, or the LOW setting 103 on the reception sensitivity setting screen 100 as appropriate, and the microcomputer 30 automatically changes the setting from a predetermined reference setting as appropriate. You may do it. For example, a desired number of selected channels 301 that the user wants to preset is set on the selected channel number setting screen 300 displayed on the CRT 40 by the OSD circuit 22 shown in FIG. 10 and stored in the EEPROM M60. The microcomputer 30 may execute the preset process so as to satisfy the number of channel selection channels 301 stored in the EEPROM 60.

FIG. 11 is a flowchart showing the contents of the preset processing executed by the microcomputer 30 when the number of selected channels 301 is set. In the figure, when the reception sensitivity setting processing is completed, the microcomputer 30 starts the preset processing. In such a case, the microcomputer 30 first reads out the number Cn of selected channels stored in a predetermined area of the EEPROM 60 (step S305). Next, the voltage control oscillator 13 is switched to enable reception of the VHFLow band (step S335). Then, the frequency divider 17 is sequentially changed by controlling the variable frequency divider 17, and tuning is attempted for all frequencies in the V HF Low band.

Then, the frequency β of the horizontal synchronization signal input via the general-purpose port is calculated (step S340), and based on whether or not this frequency β is included in the set predetermined reference frequency range α. Then, it is determined whether or not a video signal exists (step S345). If it is determined in step S345 that a video signal exists, a broadcast signal is detected, and the tuning frequency at that time is stored in the EEPROM 60 (step S350). When the broadcast signal is detected and the tuning frequency is stored in the EEPROM 60, the detection count C is incremented (step S355). Then, it is determined whether or not the scanning has been completed in all the frequency bands of the band set by the switching (step S365). Until it is determined in step S360 that the scanning in all the frequency bands has been completed. The process from step S335 is executed on the band.

Here, when it is determined in step S360 that the scanning of all frequency bands has been completed, it is determined whether or not scanning has been performed in all of the VHFLow band, the VHFHigh band, and the UHF band ( Step S365). If it is not determined in step S365 that scanning has been performed for all bands, the band is switched by controlling the voltage-controlled oscillator 13 (step S370), and the processing from step S335 is repeated. That is, after the scan of the VHFLow band is completed, the band is switched from the VHFLow band to the VHFHigh band, and after the scan of the VHFHigh band is completed, the band is switched from the VHFHigh band to the UHF band.

On the other hand, if it is determined in step S365 that scanning has been performed on all bands, the detection count C indicating the number of tuning frequencies stored in the EEPROM 60 and the number of selected channels Cn are compared in step S350. (Step S380) If the detection count C is smaller than the number of selected channels Cn, it is determined that the number of selected channels is not satisfied by the user, and the reference reception sensitivity is set to a direction in which more broadcast signals are detected. (Step S385). Then, the processing from step S335 is repeated. On the other hand, if the detected count number C is greater than or equal to the selected channel number Cn in step S380, it is determined that the number of selected channels desired by the user has been satisfied, and the tuning frequency stored in the EEPROM 60 is determined in step S350. Is preset in the EEPROM 60 as the center frequency while corresponding to the channel number (step S390).

In the above-described modification, when the detected broadcast signal is smaller than the number of selected channels, the reference receiving sensitivity is changed in a direction in which more broadcast signals are detected. If the signal is larger than the number of selected channels, a process of changing the reference reception sensitivity to a direction in which a smaller broadcast signal is detected may be included. In such a case, by changing the reference reception sensitivity to a direction in which more broadcast signals are detected and a direction in which fewer broadcast signals are detected, the detected broadcast signal is converged to the number of selected channels. It becomes possible.

(5) Conclusion: As described above, the user selects a desired reception sensitivity from the reception sensitivity selection screen 100 displayed on the CRT 40 when performing the preset, so that the preset based on the selected reception sensitivity is performed. Can be obtained. At this time, by setting the selectable reception sensitivity in the frequency range α of the horizontal synchronizing signal, a user who does not want to preset the noise-containing screen selects the LOW setting 103 in which the frequency range α is narrow. The user who wants to preset all broadcast signals selects the HIGH setting 101 having a wide frequency range α, so that the user can make a preset setting close to the desired one. Further, by executing this processing by the microcomputer 30, a simple configuration can be achieved.

[Submission date] July 9, 2001 (2001.7.9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents] [Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a television device, and more particularly to a television device capable of changing reception sensitivity when presetting a broadcast signal.

[0002]

[Prior art]

 2. Description of the Related Art Conventionally, as this type of television apparatus, there has been known a television apparatus disclosed in Japanese Patent Application Laid-Open No. H5-275978. According to the publication, when an auto search function is performed in a television device, the sensitivity of the receiver is automatically increased or decreased, so that only the necessary broadcast frequency according to the surrounding radio wave environment is reliably searched and received. A technique for storing data in a memory inside the device is disclosed. At this time, the television apparatus is provided with an antenna, a high-frequency amplifier, a frequency converter, an intermediate frequency amplifier, a sensitivity control circuit, a demodulator, a local starter, and a microcomputer. Then, first, the signal received by the antenna is amplified by the high-frequency amplifier and output to the sensitivity control circuit. Here, the sensitivity of the sensitivity control circuit is changed and controlled by a sensitivity control signal from the microcomputer. The signal whose level has been adjusted by the sensitivity control circuit is output to a demodulation unit, where the signal is demodulated into a video signal and an audio signal to enable viewing. Further, as a similar technique, one disclosed in Japanese Patent Application Laid-Open No. 1-341010 is known. This publication discloses a technique related to a radio receiver capable of automatically presetting a predetermined number of stations having a strong electric field strength by expanding the identification range of the electric field strength.

[0003]

[Problems to be solved by the invention]

 The above-described conventional television apparatus has the following problems. In the former Japanese Patent Application Laid-Open No. Hei 5-275978, it is necessary to provide a sensitivity control circuit, which complicates the circuit configuration and increases the manufacturing cost. Also, if an auto search is performed in a strong radio wave environment, the reception sensitivity is automatically reduced, and it may not be possible to detect the broadcast frequency of a weak input. When a search is performed, the reception sensitivity is automatically increased, so that even unnecessary broadcast frequencies may be detected. On the other hand, the latter JP-A-1-314010 adjusts a preset radio station by controlling the received electric field strength, and does not suggest any television apparatus.

[0004] The present invention has been made in view of the above problems, and it is possible to appropriately change the reception sensitivity when searching for a broadcast frequency with a simple configuration and a simple method, and to search for a desired broadcast frequency. The purpose of the present invention is to provide a television device capable of performing the operation.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the invention according to claim 1 performs an auto search by a microcomputer based on the frequency of a horizontal synchronization signal of a radio wave received by a tuner, stores the detected broadcast frequency in an EEPROM, and presets the broadcast frequency. The television apparatus includes a frequency width setting unit that can select and set the frequency width of the horizontal synchronization signal to be searched for when performing the auto search, and the microcomputer controls the horizontal synchronization signal of the received radio wave. The frequency is calculated, and when the calculated frequency is included in the frequency width set by the frequency width setting unit, the broadcast frequency is detected and stored in the EEPROM.

[0006] In the invention according to claim 1 configured as described above, the microcomputer automatically searches for the broadcast frequency based on the frequency of the horizontal synchronization signal of the radio wave received by the tuner, and stores the detected broadcast frequency in the EEPROM. A television apparatus that presets the horizontal synchronization signal by performing a frequency width setting of the horizontal synchronization signal to be selected when the automatic search is performed, and a microcomputer that controls the horizontal synchronization signal of the received radio wave. The broadcast frequency is calculated, and when the calculated frequency is included in the frequency width set by the frequency width setting unit, the broadcast frequency is detected and stored in the EEPROM.

With the configuration described above, it is possible to provide a television device as a specific device capable of detecting a broadcast frequency from a received radio wave based on a reception sensitivity set by a user. On the other hand, such a technical idea is not limited to a specific device to which the technology is applied, but can also be realized as a television device that detects a broadcast frequency from a radio wave received based on a selected and set reception sensitivity. Needless to say.

Therefore, the present invention provides a tuner for receiving radio waves at a set receiving frequency, a receiving sensitivity setting means for selecting and setting a receiving sensitivity when executing an auto search, and a tuner for the tuner. The reception frequency is sequentially changed and set, and it is determined whether the radio wave received by the tuner is equal to or higher than the reception sensitivity while maintaining the reception sensitivity set by the reception sensitivity setting means, and Search control means for detecting a broadcast frequency when the received radio wave has the same or higher sensitivity is provided. In the invention according to claim 2 configured as described above, the tuner receives radio waves at the reception frequency set by the search control means. When executing the auto search, the reception sensitivity can be selected and set by the reception sensitivity setting means. Here, as described above, the search control means sets the tuner to sequentially change the reception frequency while receiving the radio wave, and the radio wave received by the tuner is received by the reception sensitivity setting means. It is determined whether the sensitivity is equal to or higher than the sensitivity. Then, if the received radio wave is at or above this reception sensitivity, the broadcast frequency is detected.

[0009] As an example of a method for detecting the presence or absence of a broadcast frequency by a search control means, the invention according to claim 3 is based on the television apparatus according to claim 2, wherein two numerical data having different reception sensitivities are used. And the search control means includes frequency calculation means for calculating a frequency of a predetermined synchronization signal of the received radio wave. When the calculated frequency falls between the two numerical data, It is configured to detect the broadcast frequency. In the invention according to claim 3 configured as described above, the receiving sensitivity is configured by two different numerical data. Then, the search control means is provided with a frequency calculating means for calculating the frequency of the predetermined synchronization signal. With such a configuration, the search control means determines the presence or absence of the broadcast frequency, and determines that the broadcast frequency is present when the frequency calculated by the frequency calculation means falls between two numerical data constituting the reception sensitivity. The broadcast frequency is detected from the received radio wave.

[0010] As a preferred example of the search control means employed as a synchronization signal for calculating a frequency, the invention according to claim 4 is directed to the television apparatus according to claim 3, wherein The means is configured to use a horizontal synchronization signal superimposed on the broadcast frequency as the synchronization signal. In the invention according to claim 4 configured as described above, the frequency of the horizontal synchronization signal superimposed on the broadcast frequency is calculated by the frequency calculation means provided in the search control means. Then, the search control means detects the broadcast frequency when the frequency of the horizontal synchronization signal is included in the range of two numerical data set as the reception sensitivity.

As another example suitable for application to this synchronization signal, the invention according to claim 5 is directed to the television apparatus according to claim 3, wherein the search control means includes the synchronization signal as the synchronization signal. The configuration uses a vertical synchronization signal superimposed on the broadcast frequency. In the invention according to claim 5 configured as described above, the frequency of the vertical synchronization signal superimposed on the broadcast frequency is calculated by the frequency calculation means provided in the search control means. Then, the search control means determines that there is a broadcast frequency when the frequency of the vertical synchronization signal is included in the range of two numerical data set as the reception sensitivity.

As described above, the reception sensitivity is selected and set within a predetermined range. Here, it is preferable that the set range of the receiving sensitivity can be appropriately changed. Therefore, the invention according to claim 6 is the television device according to any one of claims 2 to 5, wherein the reception sensitivity setting means is capable of changing a range of the set reception sensitivity. It has a configuration having a changing means. In the invention according to claim 6 configured as described above, the receiving sensitivity setting means is provided with the receiving sensitivity changing means. Then, the range of the receiving sensitivity set and selected in the predetermined range by the receiving sensitivity changing means can be changed.

It is preferable that the search sensitivity can be automatically changed by the search control means in accordance with the state of the broadcast frequency. Therefore, a device according to claim 7 is the television device according to any one of claims 2 to 6, wherein the search control means changes the reception sensitivity based on the detected broadcast frequency. is there. In the invention according to claim 7 configured as described above, the search control means changes the receiving sensitivity based on the detected broadcast frequency. Then, the presence or absence of a broadcast frequency is determined based on the changed reception sensitivity.

[0014] As an example of a situation in which the reception sensitivity is changed by the search control means, the invention according to claim 8 is directed to the television apparatus according to claim 7, wherein the search control means comprises: Is larger than a predetermined threshold value, the receiving sensitivity is changed in a direction in which the number of detected broadcast frequencies decreases. In the invention according to claim 8 configured as described above, the search control means determines whether or not the number of broadcast frequency detections is greater than a predetermined threshold value. If it is larger, change the reception sensitivity in the direction that the number of detections of the same broadcast frequency decreases.

[0015] As another example of the situation where the reception control is changed by the search control means, the invention according to claim 9 is directed to the television apparatus according to claim 7, wherein the search control means is adapted to control the broadcast frequency. When the number of detections is smaller than a predetermined threshold, the reception sensitivity is changed in a direction to increase the number of detections of the broadcast frequency. In the invention according to claim 9 configured as described above, the search control means determines whether or not the number of broadcast frequency detections is greater than a predetermined threshold, and determines whether the number of broadcast frequency detections is a predetermined threshold. When the value is smaller than the value, the receiving sensitivity is changed in a direction to increase the number of detections of the same broadcast frequency. The predetermined threshold value is not particularly limited, and may be the number of detections of a desired broadcast signal by the user or may be a preset value.

[0016]

[Effect of the invention]

 As described above, the present invention enables the microcomputer to detect and preset the broadcast frequency based on the set frequency width of the horizontal synchronization signal, so that the configuration can be simplified and utilized. By appropriately setting the frequency width of the horizontal synchronization signal in accordance with the usage pattern of the user, it is possible to provide a television device capable of presetting a desired broadcast frequency. Further, according to the invention of claim 2, it is possible to detect a broadcast frequency based on a desired reception sensitivity by enabling a search for a broadcast frequency while maintaining the reception sensitivity appropriately selected and set. A simple television device can be provided. Further, according to the invention of claim 3, it can be shown as an example of a method for detecting the presence or absence of a broadcast frequency in the search control means. Further, according to the invention of claim 4, it is possible to show a preferred example which is adopted for a synchronization signal. Further, according to the invention of claim 5, another example suitable for use in a synchronization signal can be shown.

Further, according to the invention of claim 6, it becomes possible to appropriately change and set the receiving sensitivity according to the user's preference. Furthermore, according to the invention of claim 7, since the receiving sensitivity can be automatically changed and set according to the detection state of the broadcast frequency, the detection of the broadcast frequency increases as the number of detections decreases. The reception sensitivity can be changed and set at the same time, and the reception sensitivity can be changed and set so that the detection of the broadcast frequency decreases as the number of detections increases. Further, according to the inventions according to claims 8 and 9, it is possible to detect a desired number of broadcast frequencies by appropriately changing the reception sensitivity according to the number of broadcast frequencies detected.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Here, embodiments of the present invention will be described in the following order. (1) About the outline of the invention: (2) About the configuration of the television device: (3) About the embodiment: (4) About the modification: (5) Summary: Hereinafter, an embodiment of the invention will be described with reference to the drawings. I do.

(1) Concept of Invention: FIG. 1 is a schematic diagram showing a technical outline of a television device according to the present invention. Referring to FIG. 1, a television apparatus C according to the present invention includes a tuner C1, a reception sensitivity setting unit C2, and a search control unit C3. Tuner C1 receives radio waves at the set frequency. The receiving sensitivity setting means C2 can select and set the above receiving sensitivity within a predetermined range. The search control means C3 determines whether the radio wave received by the tuner C1 is equal to or higher than the set reception sensitivity while sequentially changing the reception frequency with respect to the tuner C1. Then, if the result of the determination indicates that the received radio wave is equal to or higher than the set reception sensitivity, the broadcast frequency is detected.

That is, the tuner C1 receives radio waves based on the reception frequency sequentially changed by the search control means C3, and the search control means C3 detects a broadcast frequency from the radio waves received by the tuner C1. Then, in such a case, the search control means C3 acquires the reception sensitivity selected and set by the reception sensitivity setting means C2, and determines whether or not the received radio wave is at or above this reception sensitivity. Then, when the received radio wave is equal to or higher than the reception sensitivity, the broadcast frequency is detected. In this way, by selecting and setting a desired reception sensitivity by the reception sensitivity setting means C3, it is possible to detect a desired broadcast frequency.

(2) Configuration of Television Device: FIG. 2 is a block diagram showing a main part of the television device according to an embodiment of the present invention, and FIG. 3 is a block diagram showing a configuration of a PLL tuner. . In the figure, an RF signal on which a broadcast signal is superimposed is input to a PLL tuner 10 via an antenna. The input RF signal is amplified by an amplifier 11 and input to a mixing circuit 12. You. The local oscillation signal f0 output from the voltage controlled oscillator (VCO) 13 is also input to the mixing circuit 12. The mixing circuit 12 outputs a signal representing the difference between the local oscillation signal f0 and the high-frequency amplified RF signal as an intermediate frequency signal.

The frequency of the local oscillation signal f 0 can be changed by control of the microcomputer 30, and the frequency is stabilized by feedback control. That is, the voltage controlled oscillator 13 includes a resonance circuit (not shown), and the capacitance component forming the resonance circuit is variable depending on the applied voltage. This applied voltage is supplied from the integrating circuit 14, and the voltage controlled oscillator 13 changes the frequency according to this voltage and outputs it as the local oscillation signal f0.

The local oscillation signal f 0 is also input to the variable frequency divider 17. The variable frequency divider 17 is a circuit for dividing the frequency of the input signal, and the frequency division ratio can be changed under the control of the microcomputer 30. Therefore, the microcomputer 30 can change the frequency to be tuned by changing the frequency division ratio, and can grasp the frequency. The output of the variable frequency divider 17 is input to the detection circuit 16 as a divided signal f2. On the other hand, the reference oscillator 15 is a circuit that outputs an oscillation signal from a crystal oscillator or the like via a fixed frequency divider, and its output is input to the detection circuit 16 as a reference signal f1.

The detection circuit 16 is a circuit that performs positive and negative detection outputs according to the phase difference between the two input signals. The detection output is input to the integration circuit 14 so that a DC component is extracted. The minute is input to the voltage controlled oscillator 13. The voltage controlled oscillator 13 oscillates according to the DC component as described above, and controls so that the phase difference between the divided signal f2 and the reference signal f1 converges to "0". That is, the circuit configuration is to feedback control the frequency. Further, in the voltage controlled oscillator 13, it is possible to switch a plurality of circuit configurations to make different resonance circuits effective, and the microcomputer 30 performs switching for each band, thereby controlling transmission and reception signals in a plurality of frequency bands. Tuning operation is possible.

The intermediate frequency signal output from the mixing circuit 12 of the PLL tuner 10 is input to the TVIC 20. The TVIC 20 performs various signal processing such as demodulation of a video signal and an audio signal based on the intermediate frequency signal. The video signal is subjected to video detection after amplifying the input intermediate frequency signal, and is subjected to a predetermined color demodulation process based on the detected output to output an RGB signal. This RGB signal is output to the CRT 40 via a cathode amplifier (not shown). The audio signal is subjected to audio intermediate frequency amplification and then audio detection, and is separated into a main channel audio signal and a sub channel audio signal based on the audio detection output and demodulated. The demodulated signal is output to a speaker (not shown) via a matrix circuit or an amplifier.

The TVIC 20 separates the horizontal and vertical synchronizing signals in addition to such video and audio signals. The TVIC 20 outputs the signals to perform horizontal and vertical driving on the CRT 40, and also detects when the channel selection is completed. For this purpose, the horizontal / vertical synchronization signal (SYNC) is input to a general-purpose port provided in the microcomputer 30. The microcomputer 30 calculates the frequency of the horizontal synchronizing signal input from the general-purpose port and searches for a broadcast signal while judging whether or not there is no video signal.

The microcomputer 30 determines whether there is no video signal or not in this manner, and registers a preset frequency as a center frequency while associating a frequency at which a video signal exists as a broadcast signal with each channel number. Perform the operation. In the present embodiment, tuning is attempted in all the frequency ranges of the VHF Low band, the VHF High band, and the UHF band when presetting. That is, the microcomputer 30 first switches the voltage-controlled oscillator 13 so that the VHF low band can be received. Then, the frequency division ratio of the variable frequency divider 17 is controlled to sequentially change the tuning frequency. As a result, the tuning frequency determined to be a video signal by the horizontal synchronization signal input through the general-purpose port of the microcomputer 30 Is stored in a memory (not shown). Further, the voltage-controlled oscillator 13 is switched to store the tuning frequency in the VHF High band and the UHF band. This storage operation is a preset operation.

Here, the TVIC 20 includes an AFT circuit 21 and uses the preset tuning frequency as a center frequency, and finely adjusts the frequency within a range of ± 2 MHz with respect to the center frequency. Therefore, those within this fine adjustment range should be the same station, and frequencies that are close to this “2 MHz” and within “3 MHz” with some allowance are regarded as the same station. The AFT circuit 21 is a circuit that outputs a predetermined AFT voltage generated by a difference between the frequency of the intermediate frequency signal and the reference frequency. The AFT voltage is input via an A / D input terminal of the microcomputer 30. The microcomputer 30 determines whether or not the AFT voltage input via the A / D input terminal is at a predetermined reference level, and controls the variable frequency divider 17 of the PLL tuner 10 if the AFT voltage is not at the predetermined reference level. Then, fine adjustment in the range of ± 2 MHz is performed. The TVIC 20 includes an OSD circuit 22. The OSD circuit 22 generates an OSD signal capable of forming a predetermined screen display under the control of the microcomputer 30, and outputs the OSD signal to the CRT 40 to perform the OSD display. It has become.

The microcomputer 30 executes control operations of various circuits in addition to the above. For example, an input operation performed by the user via the remote controller 50 is received, and a process corresponding to the operation content is executed. That is, when the user performs a button input operation on the remote controller 50, an infrared remote control signal corresponding to the operation content is output, and the infrared remote control signal received by the light receiving unit (not shown) is analyzed by the microcomputer 30. In both cases, operations such as channel up / down and volume up / down are performed according to the operation content. Further, the microcomputer 30 can receive a setting operation performed by the user via the remote controller 50 and store the setting contents in the EEPROM 60. The microcomputer 30 can read out the contents of the setting from the EEPROM 60 and execute a predetermined control process.

(3) Embodiment: The processing operation of the microcomputer 30 is realized by executing each program in a program execution environment including a ROM, an EEPROM 60, and the like (not shown). 4 is a general flowchart showing a schematic processing operation of the microcomputer 30 at the time. In the figure, first, the microcomputer 30 allows the user to select and set the reception sensitivity when detecting a preset broadcast signal (step S100). Next, a preset is executed based on the reception sensitivity selected and set by the user (step S200). As described above, in the present embodiment, it is possible to perform presetting according to the usage status of the user by enabling the above-mentioned search for the broadcast signal based on the reception sensitivity selected and set by the user. .

FIG. 5 shows the screen display of the reception sensitivity selection screen displayed on the CRT 40 by the OSD circuit 22 based on the control of the microcomputer 30 when the user selects and sets the reception sensitivity in step S100 described above. FIG. In the figure, a reception sensitivity selection screen 100 includes a reception sensitivity HIGH setting 101, a NORMAL setting 102, and a LOW setting 103. The user uses the remote controller 50 to select a desired setting from any of the HIGH setting 101, the NORMAL setting 102, and the LOW setting 103. The setting to be selected is highlighted and visible, and in this embodiment, the HIGH setting 101 is selected.

Here, the NORMAL setting 102 has a default setting, and the receiving sensitivity based on the normal setting content can be selected. On the other hand, in the HIGH setting 101, a receiving sensitivity having a wider sensitivity range than the receiving sensitivity set in the NORMAL setting 102 is set, and by selecting the HIGH setting 101, the search is performed in the NORMAL setting 102. More broadcast signals than the number of broadcast signals can be searched. In the LOW setting 103, the receiving sensitivity whose sensitivity range is narrower than the receiving sensitivity set in the NORMAL setting 102 is set. By selecting the LOW setting 103, the search is performed in the NORMAL setting 102. Broadcast signals smaller than the number of broadcast signals can be searched.

Here, the receiving sensitivity will be described. As described above, in the present embodiment, when searching for a broadcast signal, the frequency of the horizontal synchronization signal superimposed on the broadcast signal is used. In the broadcast signal of the NTSC system, the horizontal synchronizing signal is set at a frequency of about 15.734 kHz. Therefore, the microcomputer 30 calculates the frequency of the horizontal synchronization signal input from the general-purpose port, and searches for a broadcast signal if the frequency is approximately 15.734 kHz. FIG. 6 is a diagram showing a frequency range of the horizontal synchronization signal set as the receiving sensitivity. In the figure, the NORMAL setting is set to a frequency range of ± 0.2 kHz around 15.734 kHz, and the HIGH setting is set to a frequency range of ± 0.5 kHz around 15.734 kHz. . Therefore, in the HIGH setting, it is possible to search for a broadcast signal with a weak input, and it is possible to search for more broadcast signals than in the NORMAL setting. On the other hand, the LOW setting is set to a frequency range of ± 0.1 kHz centering on 15.5734 kHz. Therefore, it is possible to search for a broadcast signal with a strong input, and to search for less broadcast signals than the NORMAL setting.

FIG. 7 is a flowchart showing the processing contents of the reception sensitivity selection processing executed by the microcomputer 30 in step S100 described above. In the figure, when the user performs a preset operation by pressing a predetermined button on the remote controller 50, the microcomputer 30 detects this operation and activates the reception sensitivity selection processing. In such a case, first, the OSD circuit 22 is controlled to display the reception sensitivity selection screen 100 shown in FIG. 5 on the CRT 40 (step S105). When the user selects any of the HIGH setting 101, the NORMAL setting 102, or the LOW setting 103 (step S110), the selected reception sensitivity setting is acquired (step S115) and stored in a predetermined area of the EEPROM 60. (Step S120). Thereby, the receiving sensitivity is set, and the microcomputer 30 executes the preset processing based on the receiving sensitivity.

Here, the reception sensitivity may be selected by the user from selection items based on a preset frequency range of the horizontal synchronization signal, or the frequency range may be changed as appropriate according to the user's preference. You may be able to do it. FIG. 8 is a screen diagram showing a display of a reception sensitivity change screen displayed on the CRT 40 by the OSD circuit 22 when the frequency range of the reception sensitivity is changed. In the figure, a reception sensitivity change screen 200 is composed of a HIGH setting change 201, a NORMAL setting change 202, and a LOW setting change 203, and each of the setting changes 201-203 has scale bars 201a-203a and level. Positions 201b to 203b are provided. The user uses the up / down buttons of the remote controller 50 to move the level positions 201b to 203b appropriately within the range of the scale bars 201a to 203a. When the level positions 201b to 203b are moved in this way, the frequency range of the horizontal synchronization signal in each setting shown in FIG. 6 is changed. As a result, the user can appropriately change the reception sensitivity to a desired setting.

FIG. 9 is a flowchart showing the contents of the preset processing executed by the microcomputer 30 in step S 200 described above. In the figure, when the reception sensitivity setting process described above is completed, the microcomputer 30 starts the preset process. In such a case, the microcomputer 30 first reads out the reception sensitivity stored in a predetermined area of the EEPROM 60 in step S120 (step S205). Then, it is determined whether or not the reception sensitivity is the NORMAL setting (step S210). If the reception sensitivity is the NORMAL setting, the frequency range α of the horizontal synchronization signal is set to α = (15.734 ± 0.2) kHz. (Step S215). On the other hand, if the setting is not the NORMAL setting, it is determined whether the setting is the HIGH setting (step S220). If the setting is the HIGH setting, the frequency range α of the horizontal synchronizing signal is set to α = (15.734 ± 0.5) kHz. . If the setting is not the HIGH setting, it is determined that the setting is the LOW setting, and the frequency range α is set to α = (15.734 ± 0.1) kHz.

Next, switching of the voltage controlled oscillator 13 is performed so that the VHF Low band can be received (step S 235). Then, the variable frequency divider 17 is controlled to sequentially change the frequency division ratio, and tuning is attempted for all frequencies in the VHF Low band. Then, the frequency β of the horizontal synchronizing signal input through the general-purpose port is calculated (step S240), and whether the video signal exists based on whether this frequency β is included in the set frequency range α or not is determined. It is determined whether or not it is (step S245). If it is determined in step S245 that there is a video signal, a broadcast signal is detected, and the tuning frequency at that time is stored in EEPROM 60 (step S250). Then, it is determined whether or not the scanning has been completed in the entire frequency band of the band set by the switching (step S255), and the determination is made in step S255 until the scanning of the entire frequency band is determined to be completed. The process from step S235 is executed for the band.

Here, when it is determined in step S255 that scanning of all frequency bands has been completed, it is determined whether or not scanning has been performed in all of the VHFLow band, VHFHigh band, and UHF band ( Step S260). If it is not determined in step S260 that scanning has been performed for all bands, the band is switched by controlling the voltage-controlled oscillator 13 (step S265), and the processing from step S235 is repeated. That is, after the scan of the VHFLow band is completed, the band is switched from the VHFLow band to the VHFHigh band, and after the scan of the VHFHigh band is completed, the band is switched from the VHFHigh band to the UHF band. On the other hand, if it is determined in step S260 that scanning has been performed for all bands, the tuning frequency stored in the EEPROM 60 is preset in the EEPROM 60 as a center frequency while corresponding to the channel number in step S250 (step S270). .

(4) Modifications: In the above-described embodiment, a configuration is adopted in which the reception sensitivity to be set is set to the frequency range of the horizontal synchronization signal. Instead, the frequency range of the vertical synchronization signal may be adopted. The present invention is not limited to a configuration in which the user selects the HIGH setting 101, the NORMAL setting 102, or the LOW setting 103 on the reception sensitivity setting screen 100 as appropriate, and the microcomputer 30 automatically changes the setting from a predetermined reference setting as appropriate. You may do it. For example, a desired number of selected channels 301 that the user wants to preset is set on the selected channel number setting screen 300 displayed on the CRT 40 by the OSD circuit 22 shown in FIG. 10 and stored in the EEPROM M60. The microcomputer 30 may execute the preset process so as to satisfy the number of channel selection channels 301 stored in the EEPROM 60.

FIG. 11 is a flowchart showing the contents of the preset processing executed by the microcomputer 30 when the number of selected channels 301 is set. In the figure, when the reception sensitivity setting processing is completed, the microcomputer 30 starts the preset processing. In such a case, the microcomputer 30 first reads out the number Cn of selected channels stored in a predetermined area of the EEPROM 60 (step S305). Next, the voltage control oscillator 13 is switched to enable reception of the VHFLow band (step S335). Then, the frequency divider 17 is sequentially changed by controlling the variable frequency divider 17, and tuning is attempted for all frequencies in the V HF Low band.

Then, the frequency β of the horizontal synchronization signal input via the general-purpose port is calculated (step S340), and based on whether or not this frequency β is included in the set predetermined reference frequency range α. Then, it is determined whether or not a video signal exists (step S345). If it is determined in step S345 that a video signal exists, a broadcast signal is detected, and the tuning frequency at that time is stored in the EEPROM 60 (step S350). When the broadcast signal is detected and the tuning frequency is stored in the EEPROM 60, the detection count C is incremented (step S355). Then, it is determined whether or not the scanning has been completed in all the frequency bands of the band set by the switching (step S365). Until it is determined in step S360 that the scanning in all the frequency bands has been completed. The process from step S335 is executed on the band.

Here, when it is determined in step S360 that the scanning of all frequency bands has been completed, it is determined whether or not scanning has been performed in all of the VHFLow band, the VHFHigh band, and the UHF band ( Step S365). If it is not determined in step S365 that scanning has been performed for all bands, the band is switched by controlling the voltage-controlled oscillator 13 (step S370), and the processing from step S335 is repeated. That is, after the scan of the VHFLow band is completed, the band is switched from the VHFLow band to the VHFHigh band, and after the scan of the VHFHigh band is completed, the band is switched from the VHFHigh band to the UHF band.

On the other hand, if it is determined in step S365 that scanning has been performed on all bands, the detection count C indicating the number of tuning frequencies stored in the EEPROM 60 and the number of selected channels Cn are compared in step S350. (Step S380) If the detection count C is smaller than the number of selected channels Cn, it is determined that the number of selected channels is not satisfied by the user, and the reference reception sensitivity is set to a direction in which more broadcast signals are detected. (Step S385). Then, the processing from step S335 is repeated. On the other hand, if the detected count number C is greater than or equal to the selected channel number Cn in step S380, it is determined that the number of selected channels desired by the user has been satisfied, and the tuning frequency stored in the EEPROM 60 is determined in step S350. Is preset in the EEPROM 60 as the center frequency while corresponding to the channel number (step S390).

In the above-described modification, when the detected broadcast signal is smaller than the number of selected channels, the reference receiving sensitivity is changed in a direction in which more broadcast signals are detected. If the signal is larger than the number of selected channels, a process of changing the reference reception sensitivity to a direction in which a smaller broadcast signal is detected may be included. In such a case, by changing the reference reception sensitivity to a direction in which more broadcast signals are detected and a direction in which fewer broadcast signals are detected, the detected broadcast signal is converged to the number of selected channels. It becomes possible.

(5) Conclusion: As described above, the user selects a desired reception sensitivity from the reception sensitivity selection screen 100 displayed on the CRT 40 when performing the preset, so that the preset based on the selected reception sensitivity is performed. Can be obtained. At this time, by setting the selectable reception sensitivity in the frequency range α of the horizontal synchronization signal, a user who does not want to preset the screen including noises selects the LOW setting 103 in which the frequency range α is narrow. A user who wants to preset all the broadcast signals selects the HIGH setting 101 having a wide frequency range α, so that the user can perform a preset setting close to the desired one. Further, by executing this processing by the microcomputer 30, a simple configuration can be achieved.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an operation of the auto search device according to the present invention.

FIG. 2 is a block diagram illustrating a main part of the television device.

FIG. 3 is a block diagram illustrating a configuration of a PLL tuner.

FIG. 4 is a general flowchart showing a schematic processing operation of a microcomputer.

FIG. 5 is a screen diagram showing a screen display of a reception sensitivity selection screen.

FIG. 6 is a diagram illustrating a frequency range of a horizontal synchronization signal in each setting.

FIG. 7 is a flowchart showing processing contents of a reception sensitivity setting processing.

FIG. 8 is a screen diagram showing a screen display of a reception sensitivity change screen.

FIG. 9 is a flowchart showing the contents of a preset process.

FIG. 10 is a screen diagram showing a screen display of a channel selection channel number setting screen.

FIG. 11 is a flowchart showing another processing content of the preset processing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... PLL tuner 11 ... Amplifier 12 ... Mixing circuit 13 ... Voltage controlled oscillator 14 ... Integrating circuit 15 ... Reference oscillator 16 ... Detection circuit 17 ... Variable frequency divider 20 ... TVIC 21 ... AFT circuit 22 ... OSD circuit 30 ... Microcomputer 40 ... CRT 50 ... Remote control 60 ... EEPROM

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[Procedure amendment]

[Submission date] July 9, 2001 (2001.7.9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Name of device] Television device

[Utility model registration claims]

[Brief description of the drawings]

FIG. 1 is an operation conceptual diagram of a television device according to the present invention.

FIG. 2 is a block diagram illustrating a main part of the television device.

FIG. 3 is a block diagram illustrating a configuration of a PLL tuner.

FIG. 4 is a general flowchart showing a schematic processing operation of a microcomputer.

FIG. 5 is a screen diagram showing a screen display of a reception sensitivity selection screen.

FIG. 6 is a diagram illustrating a frequency range of a horizontal synchronization signal in each setting.

FIG. 7 is a flowchart showing processing contents of a reception sensitivity setting processing.

FIG. 8 is a screen diagram showing a screen display of a reception sensitivity change screen.

FIG. 9 is a flowchart showing the contents of a preset process.

FIG. 10 is a screen diagram showing a screen display of a channel selection channel number setting screen.

FIG. 11 is a flowchart showing another processing content of the preset processing.

[Description of Signs] 10 ... PLL tuner 11 ... Amplifier 12 ... Mixing circuit 13 ... Voltage controlled oscillator 14 ... Integrating circuit 15 ... Reference oscillator 16 ... Detector circuit 17 ... Variable frequency divider 20 ... TVIC 21 ... AFT circuit 22 ... OSD circuit 30 ... microcomputer 40 ... CRT 50 ... remote control 60 ... EEPROM

Claims (9)

[Utility model registration claims] 1. A television apparatus which performs an automatic search by a microcomputer based on a frequency of a horizontal synchronization signal of a radio wave received by a tuner and stores a detected broadcast frequency in an EEPROM to preset the broadcast frequency. The microcomputer includes a frequency width setting unit that can select and set the frequency width of the horizontal synchronization signal to be searched, and the microcomputer calculates the frequency of the horizontal synchronization signal of the received radio wave, and the calculated frequency is the frequency width. A television device, wherein a broadcast frequency is detected and stored in the EEPROM when the frequency is included in the frequency width set by the setting unit. 2. A tuner for receiving a radio wave at a set receiving frequency, a receiving sensitivity setting means for selecting and setting a receiving sensitivity at the time of executing an auto search, and setting the receiving frequency for the tuner by sequentially changing the receiving frequency. Determining whether the radio wave received by the tuner is equal to or higher than the reception sensitivity while maintaining the reception sensitivity set by the reception sensitivity setting unit, and determining whether the received radio wave is equal to or higher than the same reception sensitivity. An automatic search device comprising: a search control unit that detects a broadcast frequency when 3. The auto search apparatus according to claim 2, wherein said reception sensitivity is constituted by two different numerical data, and said search control means is configured to control a frequency of a predetermined synchronization signal of said received radio wave. An automatic search device comprising: frequency calculation means for calculating the broadcast frequency; and detecting the broadcast frequency when the calculated frequency falls between the two numerical data. 4. The automatic search device according to claim 3, wherein the search control means uses a horizontal synchronization signal superimposed on the broadcast frequency as the synchronization signal. 5. The automatic search device according to claim 3, wherein the search control means uses a vertical synchronization signal superimposed on the broadcast frequency as the synchronization signal. 6. The automatic search device according to claim 2, wherein said receiving sensitivity setting means has a receiving sensitivity changing means capable of changing a range of the set receiving sensitivity. An automatic search device characterized by the following. 7. The automatic search device according to claim 2, wherein said search control means changes a receiving sensitivity based on a detected broadcast frequency. . 8. The auto search apparatus according to claim 7, wherein the search control means adjusts the reception sensitivity when the number of detected broadcast frequencies is larger than a predetermined threshold value. An automatic search device characterized in that the direction is changed in a direction of decreasing. 9. The auto search device according to claim 7, wherein said search control means sets said reception sensitivity to a value equal to the number of detected broadcast frequencies when the number of detected broadcast frequencies is smaller than a predetermined threshold value. An automatic search device characterized by changing in a direction in which the number increases.