JP3083584U - television - Google Patents

Abstract

(57) [Summary] [Problem] An appropriate white balance cannot be set according to a broadcasting system. SOLUTION: In a television capable of displaying an image based on a television signal based on a plurality of broadcast systems,
The broadcast system is determined based on the difference between the television signals resulting from the difference between the systems, and the white balance is controlled according to the broadcast system. The adjustment of the white balance is performed based on preset data and the like, and this data can be set for each broadcasting system and each destination. Therefore, it is possible to provide a television that can automatically adjust to a suitable white balance for each broadcasting system and each destination with a simple configuration.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a television, and more particularly, to a television capable of receiving a television signal based on a plurality of systems.

[0002]

[Prior art]

 Conventionally, as this type of television, a television disclosed in Japanese Patent Application Laid-Open No. Hei 5-21660 is known. This publication discloses that in a television receiving signals of two or more different broadcasting systems, the frequency of the horizontal synchronization signal of the input signal is detected, and the drive ratio of the three primary colors is changed based on the detection result. White balance adjustments are made in response to In recent televisions, there are televisions configured to be able to receive the PAL system, the SECAM system, and the NTSC system. In such a television, the white balance can be adjusted using one reference value even if the system is different from the conventional one. I was adjusting.

[0003]

[Problems to be solved by the invention]

 The above-mentioned conventional television has the following problems. That is, in the former conventional example, since the broadcasting system is determined by the horizontal synchronization signal, it is difficult to distinguish between the NTSC system in Japan and the Hi-Vision system in which the width of the displayed video is different due to the difference in the system. It is possible, however, to distinguish between the PAL system, the SECAM system, and the NTSC system in which the frequency of the horizontal synchronization signal is the same or a similar value.

Normally, a standard value of the white balance differs for each system. Further, a preferred color temperature differs depending on the region, and the white balance varies depending on the destination in consideration of the influence of geomagnetism. Need to be done. Therefore, in the latter conventional example, it was not possible to set an appropriate white balance for each method or destination. The present invention has been made in view of the above problems, and has as its object to provide a television capable of automatically adjusting a proper white balance for each broadcasting system and each destination with a simple configuration.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the invention according to claim 1 is capable of inputting a television broadcast signal according to the PAL system, the NTSC system, and the SECAM system, and selecting a predetermined channel from a plurality of channels to set an intermediate frequency. A tuner that outputs a signal, a composite video signal input section that inputs a composite video signal from an external device through a predetermined connection terminal, and a video signal, a synchronization signal, and an audio signal that input the intermediate frequency signal or the composite video signal. A one-chip IC for generating a signal, a display for outputting an image based on the image signal and the synchronization signal, and a white balance adjusting circuit for adjusting a white balance by controlling a cathode voltage and a grid voltage applied to the display And the audio output based on the audio signal And an EEPROM for storing various programs and various data for controlling the internal circuit of the television, and the tuner, the one-chip IC and the white balance adjusting circuit based on the various programs stored in the EEPROM. And a microcomputer for controlling the EEPROM. The EEPROM stores white balance adjustment data for each broadcast system in advance for distinguishing between video reproduction and broadcast signal, and for each distinction. The microcomputer determines whether or not a video signal is being played back based on whether or not a composite video signal is being input from the connection terminal of the composite video signal input section. The one-chip IC determines whether or not the burst signal has a specific frequency. Whether the broadcasting system is the SECAM system or not, and Based on the frequency, it is determined whether the broadcasting system is the PAL system or the NTSC system, and the results of these determinations are output to the microcomputer. The microcomputer refers to the EEPROM and matches the white balance that matches the determination result. The configuration is such that the white balance adjustment circuit is controlled so as to adjust the white balance with the adjustment data.

In the invention according to claim 1 configured as described above, it is possible to display an image on both a radio wave and a VCR on a television, and a PAL system and an NTSC system by a tuner. TV broadcast signals in accordance with the standard system and the SECAM system can be selected to obtain an intermediate frequency signal. Also, a composite video signal can be input from an external device via a predetermined connection terminal at the composite video signal input section. The intermediate frequency signal or the composite video signal is converted into a video signal, a synchronization signal, and an audio signal by signal processing of a one-chip IC, and a display outputs a video based on the video signal and the synchronization signal. Further, the white balance can be adjusted by controlling the cathode voltage and the grid voltage applied to the display by the white balance adjustment circuit. The speaker outputs a sound based on the sound signal.

Further, the EEPROM stores various programs and various data for controlling the internal circuit of the television, and the microcomputer controls the tuner and the one-chip IC based on the various programs stored in the EEPROM. And the white balance adjustment circuit and the EEPROM. In this configuration, the EEPROM stores white balance adjustment data for each broadcasting system in advance for distinguishing between video reproduction and broadcast signal use, and the microcomputer controls the connection terminal of the composite video signal input section. It is determined whether or not the video is being reproduced based on whether or not a composite video signal is input from the CPU, and the broadcast system is determined based on the output of the one-chip IC. Then, the white balance adjustment circuit is controlled so as to adjust the white balance with the white balance adjustment data that matches the determination result with reference to the EEPROM. Here, the one-chip IC determines whether or not the broadcasting system is the SECAM system based on whether or not the burst signal has the specific frequency, and further determines whether the broadcasting system is PAL based on the frequency of the vertical synchronization signal. It discriminates between the system and the NTSC system, and outputs the results of these decisions to the microcomputer.

[0008] That is, the microcomputer determines whether the image display is based on the broadcast signal or the composite video signal, and controls the white balance based on the determination result so as to obtain an appropriate white balance. Also, it determines whether the broadcasting system is PAL, NTSC, or SECAM, and performs control so that an appropriate white balance is obtained based on the determination result. This determination is made based on the video signal being displayed, and the determination result can be appropriately reflected only by referring to the white balance adjustment data stored in advance in the EEPROM. Therefore, it is possible to automatically adjust the appropriate white balance for each broadcasting system with a simple configuration.

[0009] The invention according to claim 2 is a television signal receiving means for receiving a television signal based on at least two broadcast systems of the PAL system, the NTSC system, and the SECAM system, Means for displaying a predetermined image on a picture tube based on the television signal received by the means, and the broadcast system is determined based on the television signal received by the television signal receiving means. And a white balance adjusting means for controlling the video display means and adjusting an image so as to obtain a white balance suitable for the broadcasting method determined by the broadcasting method determining means. is there.

[0010] In the invention according to claim 2 configured as described above, the television signal receiving means receives a television signal based on at least two or more broadcast systems of the PAL system, the NTSC system, and the SECAM system. . The video display means displays a predetermined video on a picture tube based on the television signal received by the television signal receiving means. In the configuration capable of displaying an image in this manner, the broadcasting method determining means determines the broadcasting method based on the television signal received by the television signal receiving means, and the white balance adjusting means determines whether or not the white balance adjusting means has the image displaying means. And adjusts the image so as to obtain a white balance suitable for the broadcast system determined by the broadcast system determination means.

That is, in a television on which two or more broadcast systems are received and a video is displayed, a broadcast system is determined based on a broadcast signal being received, and a white color is determined so as to conform to the broadcast signal being received. The balance is adjusted. Here, the television signal receiving means only needs to be able to receive a television signal based on at least two or more of the PAL system, the NTSC system, and the SECAM system. It can be configured by a tuner or the like that can scan the frequency band of the carrier of the signal.

The image display means only needs to be able to display an image on a picture tube based on a television signal, performs predetermined signal processing on a broadcast signal, separates the broadcast signal into a video signal and a synchronizing signal, and appropriately applies the signal to the picture tube. It can be constituted by a one-chip IC for applying an appropriate voltage, a predetermined signal amplifier circuit, or the like. The white balance adjusting means only needs to be able to adjust the video so as to obtain a white balance suitable for the broadcasting system. There are various methods for adjusting the white balance, such as adjusting the voltage applied to the cathode and grid of the picture tube and the amount of current of each color beam, or by instructing a one-chip IC or chroma IC. This can be realized by relatively changing the level of the output signal of each color, the color difference signal, and the like.

Further, a signal for displaying an image on a television is not limited to a broadcast wave, and it is convenient if a white balance of another signal can be appropriately adjusted. As an example of such a configuration, the invention according to claim 3 is characterized in that the broadcast system determination means determines whether the received television signal is a signal from a radio wave or obtained from an external device through a predetermined connection terminal. The white balance adjusting means is configured to adjust the image based on the discrimination so that the image has a white balance that is appropriate for both the radio wave and the one obtained from an external device via a predetermined connection terminal. It is.

In the invention according to claim 3 configured as described above, a television signal is obtained from an external device via a predetermined connection terminal. The video display means can display a predetermined video on the picture tube based on the acquired television signal from the external device. Further, the above-mentioned broadcast system determining means can determine whether the received television signal is a signal from a radio wave or a signal obtained from an external device through a predetermined connection terminal. The video is adjusted so that the white balance is appropriate for both the original and the one obtained from the external device via the predetermined connection terminal.

That is, not only broadcast radio waves but also a television that displays an image using an external device television signal supplied by connecting a predetermined cable to a predetermined connection terminal also includes a broadcast radio wave and an external device television signal. Appropriate white balance adjustments can be made for each of the above. Of course, here too, adjust so that the white balance is adapted to the broadcasting system. The predetermined connection terminal only needs to be able to acquire a television signal from an external device, and is configured to acquire an external device television signal from various external devices such as a VCR, a DVD deck, and a personal computer. be able to.

Of course, in addition to these external devices, a configuration can also be adopted in which television signals are obtained from a CATV broadcast set-top box. Further, various types of external device television signal acquisition modes can be adopted, such as a terminal for inputting a composite video signal in which a luminance signal and a chrominance signal are combined, and a method of dividing the luminance signal and the chrominance signal. It can be obtained at the input terminal or the like, or may be a digital signal input terminal for inputting predetermined digital data.

Further, the broadcast system determination means only needs to be able to determine the broadcast system based on the television signal received by the television signal reception means, and various methods can be adopted. As an example of the configuration, the invention according to claim 4 is configured so that the broadcast method determination means determines that the received television signal is the SECAM method when a burst signal of a certain frequency does not exist in the received television signal. In other words, since there is no burst signal of a certain frequency, such as a burst signal of two kinds of frequencies in the SECAM system, it is possible to determine that the broadcasting system is the SECAM system when there is no burst signal of a certain frequency. it can.

Further, in the invention according to claim 5, the broadcast system determination means determines a frequency of a vertical synchronization signal superimposed on the received television signal, and determines a PAL system and an NTSC system based on a difference in the frequency. Is determined. That is, the vertical synchronizing signal differs between 50 Hz and 60 Hz between the pal system and the NTSC system, and if this frequency difference is determined, it is easy to determine whether the signal being displayed is the PAL system or the NTSC system. Can be determined. The frequency of the vertical synchronizing signal is the same between the PAL system and the SECAM system. However, after determining whether or not the system is the SECAM system as described above, when it is determined that the system is not the SECAM system, the above-described operation is performed. By performing the frequency determination of the vertical synchronization signal, it is possible to determine whether the system is the PAL system or the NTSC system.

In the invention according to claim 6, the video display means includes a PLL means for performing stable oscillation in the same phase as a burst signal superimposed on the received television signal. The discriminating means is configured to discriminate between the PAL system and the NTSC system based on a difference in lock frequency in the PLL unit. That is, the burst signal is used by the PLL oscillator to generate a signal having the same frequency and the same phase as the burst signal when demodulating the carrier chrominance signal. Further, since the frequency of the burst signal is different between the PAL system and the NTSC system, it is possible to determine which of the two is by detecting the difference in the lock frequency in the PLL oscillator.

Further, as a specific example for adapting to the broadcasting system by the white balance adjusting unit, the invention according to claim 7 is characterized in that the white balance adjusting unit is provided for each broadcasting system stored in a predetermined storage unit in advance. The configuration is such that the white balance is adjusted so as to obtain the white balance for each broadcasting system by referring to the white balance adjustment data. In other words, since the default value for adjusting the white balance is stored in advance in the storage means for each broadcasting method, the means for adjusting the white balance refers to the default value to determine the appropriate value for each broadcasting method. Can be adjusted to white balance.

As described above, there are various methods for adjusting the white balance. In order to adjust the voltage applied to the cathode and grid of the picture tube, the amount of current of each color beam, etc., for example, a microcomputer is used. It is possible to adopt a configuration in which a circuit capable of adjusting a voltage value or a current value by control is configured and an applied voltage value or a current value is stored as data as the white balance adjustment data. When relatively changing the level of the signal of each color or the color difference signal to be output by instructing the one-chip IC or the chroma IC, the gain of the one-chip IC is adjusted by controlling the microcomputer, and the color signal or the color signal is changed. A configuration for adjusting the level of the color difference signal can be employed.

The invention according to claim 8 is a preferred configuration for achieving an appropriate white balance according to various cases, wherein the storage means stores the external device via a television signal by radio waves and a predetermined connection terminal. White balance adjustment data for each broadcasting system for each of the television signals obtained from the TV system, and the white balance adjustment means includes a television signal obtained by radio waves and a TV signal obtained from an external device through a predetermined connection terminal. It is configured to perform white balance adjustment according to the broadcasting system for each of the John signal. That is, regardless of whether the video display on the picture tube is based on an external device television signal or a radio broadcast signal, the white balance adjustment data in each case is stored. An appropriate white balance can be adjusted for each method.

Further, in the invention according to claim 9, the storage means further stores white balance adjustment data for each destination for each broadcasting system, and the white balance adjustment means is stored in a predetermined storage means at the time of shipment. Refers to the destination data obtained, and adjusts the white balance according to the broadcast system for each of the television signal by radio waves and the television signal obtained from the external device via a predetermined connection terminal, and according to the destination. Is performed.

That is, the preferred color temperature differs depending on the region, and the geomagnetism may affect the white balance. In order to accurately cope with the difference in these situations, the white balance is changed for each destination. Need to be done. Therefore, if the white balance adjustment data is stored for each destination, it is possible to adjust the white balance appropriately for each destination by referring to the destination data preset at the time of shipment.

Further, the invention according to claim 10 receives a television signal based on at least two or more broadcast systems of the PAL system, the NTSC system, and the SECAM system, and determines the broadcast system based on the television signal. In addition, in a television that performs signal processing for each broadcasting system to display a predetermined image on a picture tube, when performing the above signal processing, a white image for adjusting the image so as to have a white balance suitable for the determined broadcasting system is used. It is configured to include balance adjusting means. In other words, the present invention can be realized by additionally providing a white balance adjusting means in a conventional television capable of receiving television signals of a plurality of broadcasting systems and displaying an image. Of course, it is also possible to adopt a configuration corresponding to claims 3 to 9 described above.

[0026]

[Effect of the invention]

 As described above, the present invention can provide a television that can be automatically adjusted to an appropriate white balance for each broadcasting system with a simple configuration. Further, according to the invention of the second aspect, the white balance is automatically adjusted so as to match the broadcast signal being received. Further, according to the present invention, appropriate white balance adjustment can be performed for each of the broadcast radio wave and the external device television signal.

Further, according to the invention of claim 4, it is possible to easily determine that the system is the SECAM system. Further, according to the invention of claim 5, it is possible to easily determine whether the system is the PAL system or the NTSC system. Furthermore, according to the invention of claim 6, it is possible to easily determine whether the system is the PAL system or the NTSC system.

Further, according to the invention of claim 7, it is possible to adjust to an appropriate white balance for each broadcasting system. Furthermore, according to the invention of claim 8, whether the video display on the picture tube is based on an external device television signal or a radio broadcast signal is appropriate for each system in each case. White balance can be adjusted. Further, according to the invention of claim 9, the white balance can be adjusted accurately for each destination. Further, according to the present invention, the present invention can be realized by adding a white balance adjusting means to the conventional television.

[0029]

[Embodiment of the invention]

 Here, embodiments of the present invention will be described in the following order. (1) Configuration of television: (1-2) Aspect of television signal: (1-3) Configuration of one-chip IC: (1-4) Processing and operation of the present invention: (2) Second embodiment: (3) Third embodiment:

(1) Configuration of Television: FIG. 1 is a schematic block diagram showing a television according to the first embodiment of the present invention. In the present embodiment, a television signal by radio waves and a cable are used. Each of the acquired television signals is controlled to have an appropriate white balance for each broadcasting system. In FIG. 1, a tuner 30 includes an antenna 31 as an input source of a television signal by radio waves. Also, a composite video signal input terminal 50 is provided as a television signal input source via a cable. Both can input television signals in the SECAM, PAL, and NTSC systems. Therefore, the tuner 30, the antenna 31, and the composite video signal input terminal 50 serve as the television signal receiving means.

The antenna 31 receives a signal of a desired frequency corresponding to the broadcast band of the television signal, selects only a required signal from the received signal, amplifies the signal at a high frequency, and converts the signal into an intermediate frequency signal (IF). Convert and output. The tuner 30 in the present embodiment employs a so-called PLL-type channel selection mechanism. The tuner 30 directly controls the local oscillation frequency based on predetermined frequency data input from a microcomputer 40, which will be described later. The frequency can be controlled.

(1-2) Aspects of Television Signal: FIG. 2 is an explanatory diagram for explaining differences between television signals in each of the SECAM system, the PAL system, and the NTSC system. In the figure, a television signal is schematically shown with the horizontal direction as a time axis, and in the case of a television signal by radio waves, such a signal is actually broadcast while being superimposed on a carrier wave for each channel. . The television signal is composed of a periodic synchronizing signal and a video signal for forming an image on each scanning line. The synchronizing signal includes a vertical synchronizing signal Vsync and a horizontal synchronizing signal Hsync. The vertical synchronization signal Vsync is a pulse signal superimposed so as to define the period of one field, and the horizontal synchronization signal Hsync is a signal on a pulse superimposed so as to define the period of each scanning line. is there. A burst signal for demodulating the carrier chrominance signal is superimposed on the back porch of the horizontal synchronization signal Hsync.

The frequency of the vertical synchronizing signal, the frequency of the burst signal, and the like are different due to the difference between the respective broadcasting systems. As shown in the figure, the frequency of the vertical synchronizing signal is 50 Hz in the SECAM system and the PAL system. , And 60 Hz in the NTSC system. Further, the frequency of the burst signal in the present embodiment is 4.43 MHz in the PAL system and 3.58 MHz in the NTSC system. In the SECAM system, burst signals having frequencies of 4.25 MHz and 4.41 MHz are alternately superimposed.

(1-3) Configuration of One-Chip IC: The tuner 30 receives a carrier wave corresponding to each channel frequency, performs demodulation and performs the high-frequency amplification, and transmits an intermediate frequency signal to the one-chip IC 20. The composite video signal input terminal 50 receives the composite video signal as shown in FIG. 2 and outputs it to the one-chip IC 20. The one-chip IC 20 is generally configured as shown in FIG. 3, and performs various signal processing. In the figure, a composite video signal input to a one-chip IC 20 is supplied to a burst signal detection unit via a signal detection unit 21.

When the composite video signal is input, the signal detection unit 21 outputs a signal to the microcomputer 40 via the IIC bus to the effect that a later-described composite video signal is being processed. The burst signal detector 22 acquires the intermediate frequency signal and the composite video signal, and determines whether or not the burst signal shown in FIG. 2 has a certain frequency. When it is determined that the burst signal has a constant frequency, a signal indicating this is output to the microcomputer 40. The burst signal detector 22 further outputs the intermediate frequency signal and the composite video signal to the SECAM type demodulator 24 and the vertical synchronization signal detector 23. The SECAM system demodulation unit 24 is a circuit that performs predetermined signal processing on an input signal and performs demodulation corresponding to the SECAM system. The demodulated signal is output to a CRT 32 described later.

The vertical synchronizing signal detector 23 detects a vertical synchronizing signal from the input intermediate frequency signal or composite video signal, and sends a signal indicating whether or not the frequency is 50 Hz to the microcomputer 40. Output. The vertical synchronization signal detector 23 is connected to the PAL demodulator 25 and the NTSC demodulator 26, and supplies the intermediate frequency signal and the composite video signal to the PAL demodulator 25 and the NTSC demodulator 26. Is done. The PAL demodulation unit 25 is a circuit that performs predetermined signal processing on an input signal and performs demodulation corresponding to the PAL system. The NTSC demodulation unit 26 performs predetermined signal processing on the input signal. And performs demodulation corresponding to the NTSC system.

The signals demodulated by the PAL system demodulation unit 25 and NTSC system demodulation unit 26 are output to a CRT 32 described later. The SECAM demodulation unit 24 applies a bell filter (not shown) to the SECAM composite video signal, and switches the sub-carrier frequency at the time of demodulation as appropriate based on the timing of the horizontal synchronizing signal to convert the carrier chrominance signal. The signal is demodulated to obtain a color difference signal. Further, the luminance signal is separated through a predetermined filter.

The PAL system demodulation unit 25 and the NTSC system demodulation unit 26 separate the luminance signal and the carrier chrominance signal, generate a subcarrier from the burst signal, and demodulate the carrier chrominance signal with the subcarrier appropriately. Then, a color difference signal is obtained. Further, in each of the SECAM system demodulation unit 24, PAL system demodulation unit 25, and NTSC system demodulation unit 26, an RGB signal is generated from the color difference signal and the luminance signal, and output to the CRT 32. Each demodulator outputs various other signals for displaying images, generates signals to be supplied to a grid of the CRT 32, etc., and supplies them to the CRT 32. As a result, a predetermined image is displayed on the CRT 32. That is, the one-chip IC 20 constitutes the image display means.

On the other hand, the white balance adjustment unit 27 is a circuit that applies a voltage to the cathode and grid of the CRT 32 while appropriately adjusting the voltage according to an instruction from the microcomputer 40 described later. Therefore, the white balance adjustment unit 27 can adjust the white balance on the CRT 32 by adjusting the voltage applied to the cathode and grid of the CRT 32 in accordance with an instruction from the microcomputer 40. The one-chip IC 20 also has various other circuit configurations (not shown). The one-chip IC 20 receives an audio signal superimposed on a television signal by radio waves or an audio signal of the composite video signal, and detects and amplifies the signals as appropriate. To output an audio signal to the speaker 33.

Control of the entire television set, such as tuning control of the tuner 30, is performed by the microcomputer 40. The microcomputer 40, the tuner 30, the one-chip IC 20 and the EEPROM 60 are connected to a predetermined IIC bus, and can communicate with each other via the IIC bus. For example, regarding the tuning control of the tuner 30, when a remote controller (not shown) is operated to select a desired channel, a corresponding infrared remote control signal is transmitted from the remote controller (not shown). The microcomputer 40 receives the infrared remote control signal via an infrared light receiving unit (not shown), detects a channel to be selected, and sends the corresponding frequency data to the tuner 30 via the IIC bus. Then, the tuner 30 tunes to the channel frequency based on the same frequency data.

The EEPROM 60 stores, in addition to various programs executed by the microcomputer 40, set values in a factory mode and white balance adjustment data 41 as shown in FIG. In the figure, only the destination data is shown as the set value in the factory mode, and D is set as the destination. In the white balance adjustment data 41, a radio signal and a video signal (composite video signal) are distinguished, and each of the radio signal and the video signal is distinguished for each of the SECAM system, the PAL system, and the NTSC system. Further, data is provided for each destination.

Each data is composed of cathode applied voltages V 1 to V 10 and grid applied voltages V 1 ′ to V 10 ′. More specifically, each applied voltage is defined for each of RGB colors. The microcomputer 40 refers to the cathode applied voltages V1 to V10 and the grid applied voltages V1 'to V10', and outputs a control signal to the white balance adjustment unit 27 of the one-chip IC 20 via the IIC bus. As a result, the white balance adjusting unit 27 adjusts the cathode applied voltages V1 to V10 of the CRT 32 and the grid applied voltages V1 'to V10', and on the CRT 32, the white balance as indicated by the white balance adjustment data is obtained. Become. As described above, the white balance adjusting section 27 constitutes the white balance adjusting means.

That is, by adjusting the cathode applied voltage, the drive current of each color in the CRT 32 can be changed, and by adjusting the grid applied voltage, the cutoff voltage in the electron gun of the CRT 32 can be changed. Therefore, the white balance of the CRT 32 can be adjusted by adjusting these applied voltages for each of the RGB colors. As for the white balance, a preferable adjustment value differs depending on each of the SECAM system, the PAL system, and the NTSC system, and a preferred white balance differs depending on the destination. In addition, there are destinations that need to consider the effects of geomagnetism.

Therefore, by defining the white balance adjustment data 41 for each system and destination, and storing appropriate adjustment data in the EEPROM 40 in advance, an appropriate white balance can be obtained. Further, in the present embodiment, since the radio broadcast and the video signal are distinguished from each other, it is possible to accurately adjust the white balance in the case of these signals. Depending on the destination, radio waves in both the SECMA system and the PAL system can be received. In such a destination, the white balance adjustment data 41 is stored for each of a plurality of broadcast systems.

In the present embodiment, as described above, since the video display of the CRT 32 is performed while determining the broadcast system by the processing of the one-chip IC 20, the microcomputer 40 determines the broadcast system so that the appropriate white balance of the broadcast system can be obtained. It can be adjusted so that The white balance adjustment data 41 of the destination D in the figure is an example, and in consideration of the fact that the destination D can receive both the SECAM and PAL radio waves, the destination D is The EEPROM 60 stores cathode applied voltages V4, V5, V9, V10 and grid applied voltages V4 ', V5', V9 ', V10'. Of course, for the composite video signal, the data to be stored can be selected as necessary, such as storing the white balance adjustment data 41 for all the broadcasting systems at all times.

(1-4) Processing and Operation of the Present Invention: FIG. 5 is a flowchart showing the above-described one-chip IC 20 for determining the broadcast system. When the television 10 according to the present embodiment starts driving, the one-chip IC 20 constantly repeats the processing shown in this flowchart. In step S100, the signal detection unit 21 of the one-chip IC 20 detects whether or not a composite video signal has been input via the composite video signal input terminal 50, and determines that a composite video signal has been input. When this is done, a signal indicating that fact is output to the microcomputer 40 in step S102.

Subsequently, in step S104, the burst signal detector 22 detects the frequency of the burst signal and determines whether the detected frequency is a constant frequency. That is, as shown in FIG. 2, the burst signal is constant in the PAL system and the NTSC system, whereas in the SECAM system, two kinds of frequencies appear alternately. Therefore, if the frequency of the burst signal is not determined to be the constant frequency in step S104, a signal indicating the SECAM system is output to the microcomputer 40 in step S110.

If it is determined in step S104 that the frequency of the burst signal is a constant frequency, the signal being processed is determined to be the PAL system or the NTSC system, and in step S120, the vertical synchronization signal detecting unit 23 is determined. Detects the vertical synchronizing signal and determines whether or not the frequency is 50 Hz. That is, as shown in FIG. 2, when the PAL system and the NTSC system are compared, the frequency of the vertical synchronizing signal is different between them. The PAL system is 50 Hz and the NTSC system is 60 Hz. Therefore, when it is determined in step S120 that the frequency of the vertical synchronization signal is 50 Hz, a signal indicating the PAL system is mainly output to the microcomputer 40 in step S130. If it is determined in step S120 that the frequency of the vertical synchronizing signal is 60 Hz, a signal indicating the NTSC system is output to the microcomputer 40 in step S140.

On the other hand, the microcomputer 40 performs a method determination based on the signals output by the one-chip IC 20 in steps S 102, S 110, S 130, and S 140, and performs adjustment so as to obtain an appropriate white balance. FIG. 6 is a flowchart for the processing. The microcomputer 40 determines a signal input via the IIC bus when adjusting the white balance. In step S200, first, it is determined whether or not the television 10 is inputting a composite video signal based on whether or not the signal detection unit 21 has output a predetermined signal in step S102.

If it is determined in step S 200 that a composite video signal is being input, the microcomputer 40 turns on a predetermined video signal flag in step S 210. If it is not determined in step S200 that the composite video signal is being input, the microcomputer 40 turns on a predetermined radio signal flag in step S220. Here, when the video signal flag is on, it indicates that the composite video signal is being processed, and when the radio signal flag is on, it indicates that the radio signal is being processed.

The microcomputer 40 further receives the predetermined signal output from the one-chip IC 20 in step S225, grasps the broadcast system of the signal being processed, and sets the factory mode with reference to the EEPROM 60 in step S230. Know the destination that was set. Since the microcomputer 40 knows the signal acquisition mode (whether it is a radio wave or a video signal via a terminal), the broadcasting system, and the destination in the above processing, the corresponding white balance is determined in step S240. With reference to the adjustment data 41, the reference data is output to the one-chip IC 20 in step S250. As a result, the white balance adjusting unit 27 of the one-chip IC 20 adjusts the white balance as instructed by the microcomputer 40, that is, the white balance appropriately corresponding to the acquisition mode of the signal being processed, the broadcasting system, and the destination. The voltage applied to the cathode and the voltage applied to the grid are controlled. As described above, the one-chip IC 20 and the microcomputer 40 cooperate with each other to perform the system discrimination processing, and in this sense, the one-chip IC 20 and the microcomputer 40 constitute the above-mentioned broadcasting system discrimination means.

Hereinafter, the operation of the present embodiment configured as described above will be described. In the following description, it is assumed that the television 10 is a product for the destination D, and the destination D is previously set in the EEPROM 60 in the factory mode. It is also assumed that the destination D can receive a television signal by both the SECAM radio wave and the PAL radio wave. When the power of the television 10 is turned on, the user can select a desired channel by operating a remote controller (not shown) or the like, and can watch video / audio based on the electric wave broadcast.

When the user selects a broadcast channel according to the SECAM system, the tuner 30 extracts an intermediate frequency signal using a signal of the corresponding channel frequency and outputs the signal to the one-chip IC 20. The one-chip IC 20 determines in step S100 that no composite signal has been detected, and determines in step S104 that the burst signal is not at a constant frequency. As a result, the burst signal detection unit 22 outputs a signal indicating that it is the SECAM system in step S110. At this time, the SECAM system demodulation unit 24 is driven to demodulate the SECAM system composite signal and display an image on a predetermined CRT 32.

While the tuner 30 is operating, the microcomputer 40 does not determine in step S 200 that a composite video signal is being input, and turns on the radio signal flag in step S 220. Further, in step S225, it is determined based on the signal output from the one-chip IC 20 that the signal being processed is in the SECAM system. In step S230, it is determined that the destination is D by referring to the EEPROM 60. Then, in step S240, the cathode applied voltage is set to V4 and the grid applied voltage is set to V4 'with reference to the white balance adjustment data 41. The microcomputer 40 outputs signals indicating these voltages in step S250, and the white balance adjustment unit 27 of the one-chip IC 20 performs voltage control on the CRT 32 to set the cathode applied voltage to V4 and the grid applied voltage to V4 '. Therefore, the white balance is appropriately adjusted to the destination D and the SECAM system radio wave.

On the other hand, when the user selects a broadcast channel according to the PAL system, the tuner 30 extracts an intermediate frequency signal using a signal of the corresponding channel frequency and outputs the signal to the one-chip IC 20. The one-chip IC 20 determines that the composite signal has not been detected in step S100, but determines in step S104 that the burst signal has a constant frequency. Therefore, the process proceeds to the process in step S120, and in the same step, it is determined that the frequency of the vertical synchronization signal is 50 Hz. As a result, the vertical synchronization signal detector 23 outputs a signal indicating that the PAL system is used in step S130. At this time, the PAL demodulation unit 25 is driven to demodulate the PAL composite signal and display an image on a predetermined CRT 32.

The microcomputer 40 does not determine in step S 200 that a composite video signal is being input, and turns on the radio signal flag in step S 220. Further, in step S225, it is determined based on the signal output from the one-chip IC 20 that the signal being processed is the pal system. In step S230, it is determined that the destination is D by referring to the EEPROM 60. Then, in step S240, referring to the white balance adjustment data 41, the cathode applied voltage is set to V5 and the grid applied voltage is set to V5 '. The microcomputer 40 outputs signals indicating these voltages in step S250, and the white balance adjustment unit 27 of the one-chip IC 20 performs voltage control on the CRT 32 to set the cathode applied voltage to V5 and the grid applied voltage to V5. '. Therefore, the white balance is adjusted appropriately to the destination D and the radio waves of the PAL system.

When the user does not receive a television signal by radio waves on the television 10 and watches a reproduced video image or the like via the composite video signal input terminal 50, the one-chip IC 20 includes the tuner. The composite video signal is supplied not from the terminal 30 but from the composite video signal input terminal 50. At this time, the one-chip IC 20 determines that the composite video signal has been detected in step S100, and outputs a signal indicating that the composite signal is being processed in step S102.

On the other hand, the microcomputer 40 recognizes that a composite video signal is being input in step S200, and turns on the video signal flag in step S210. The other operations in the one-chip IC 20 and the microcomputer 40 are the same as described above. However, since the video signal flag is on, the white balance adjustment data 41 includes V9, V9 ′, V10, V10 'Is selected and controlled so as to obtain an appropriate white balance.

(2) Second Embodiment In the above embodiment, the white balance is adjusted by adjusting the voltage applied to the cathode and the voltage applied to the grid. In the present invention, an image is displayed on the CRT 32. It is sufficient that the white balance can be adjusted as a result at this time, and the configuration is not necessarily limited to the above configuration. For example, the white balance may be adjusted by adjusting the gains of the RGB signals output from the one-chip IC 20 to adjust the signal levels output from the one-chip IC 20 relatively.

FIG. 7 is a block diagram showing a schematic configuration of such a one-chip IC 200 according to the second embodiment. The main configuration of the one-chip IC 200 is the same as that of the one-chip IC 20 shown in FIG. 3, but the configuration for adjusting the white balance is different, and the level control unit 270 is used instead of the white balance adjustment unit 27. It has. The same components as those of the one-chip IC 20 are denoted by the same reference numerals as those in FIG. The level control unit 270 is provided at a stage subsequent to each of the SECAM system demodulation unit 24, the PAL system demodulation unit 25, and the NTSC system demodulation unit 26, and is a circuit for amplifying the demodulated RGB signals.

The level control section 270 can change the gain of the RGB signal independently for each color based on the instruction from the microcomputer 40. Accordingly, the intensity of the RGB signals changes, and the color components displayed on the CRT 32 change, so that the white balance changes. In this embodiment, the division and the basic concept of the white balance adjustment data 41 stored in the EEPROM 60 are the same as those in the first embodiment, but the data to be stored is determined by the amplification factor for each color or the appropriate amplification factor. This is the data to instruct. If the microcomputer 40 is configured to refer to the data and instruct the level control unit 270 based on the data, the television signal acquisition mode and the broadcasting method can be determined by the same flow as in FIGS. The white balance can be adjusted appropriately according to the distinction from the destination.

(3) Third Embodiment In the above-described embodiment, whether the PAL system or the NTSC system is used is determined based on the frequency of the vertical synchronizing signal. The determination index is not necessarily limited to the vertical synchronizing signal. For example, when a subcarrier is oscillated from a burst signal, a PLL oscillator locks the frequency so as to have the same frequency as the burst signal to obtain an oscillation signal. By analyzing the lock frequency, a burst signal is obtained. The frequency can be determined, and the PAL system or the NTSC system may be distinguished based on the determined frequency.

That is, as shown in FIG. 2, the frequency of the burst signal is constant and different from each other in the PAL system and the NTSC system. Therefore, it is possible to distinguish between the PAL system and the NTSC system based on such a difference in frequency. FIG. 8 is a block diagram of a one-chip IC 201 according to the third embodiment that employs such a method. The main configuration of the one-chip IC 201 is the same as that of the one-chip IC 20 shown in FIG. 3, but the configuration for distinguishing the PAL system or the NTSC system is different. The configuration of the sub-carrier generation circuit 230 is different. The same components as those in the one-chip IC 20 are denoted by the same reference numerals as those in FIG. Although not shown, a circuit for generating the sub-transport is also provided in the above embodiment.

However, the subcarrier generation circuit 230 in the present embodiment can cause the microcomputer 40 to identify the lock frequency. That is, the sub-carrier generation circuit 230 outputs an oscillation signal while locking to the frequency of the burst signal by the PLL oscillator, and outputs a signal for recognizing the frequency at the time of this locking. Of course, the lock frequency value may be coded, but any other signal may be used as long as it can indicate which frequency it is, and various signal modes can be adopted. The microcomputer 40 may determine whether the signal is of the PAL system or the NTSC system based on this signal. In this embodiment, the microcomputer 40 can accurately determine whether the television signal is acquired, the broadcasting system, and the destination. The balance can be adjusted.

The configuration for determining the broadcasting system in the present invention is not limited to the above example, but the broadcasting system can be determined by various indexes according to the difference in the signal format of the broadcasting system. That is, if the signal mode is different due to a difference between the systems, such as the N-PAL system, the M-PAL system, and the 4.43 NTSC system, the system can be determined by detecting the difference.

As described above, in a television capable of displaying a video based on a television signal based on a plurality of broadcasting systems, a broadcasting system is determined based on a difference between television signals resulting from a difference between the systems. Control to achieve white balance according to the broadcasting system. The adjustment of the white balance is performed based on preset data and the like, and this data can be set for each broadcasting system and each destination. Therefore, it is possible to provide a television capable of automatically adjusting the white balance appropriately for each broadcasting system and each destination with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing a television according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining differences in television signals between the SECAM system, the PAL system, and the NTSC system.

FIG. 3 is a block diagram illustrating a schematic configuration of a one-chip IC.

FIG. 4 is a diagram showing white balance adjustment data.

FIG. 5 is a flowchart showing a process of determining a broadcast system in a one-chip IC.

FIG. 6 is a flowchart when a microcomputer performs white balance adjustment.

FIG. 7 is a block diagram illustrating a schematic configuration of a one-chip IC.

FIG. 8 is a block diagram illustrating a schematic configuration of a one-chip IC.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Television 20 ... Chip IC 21 ... Signal detection part 22 ... Burst signal detection part 23 ... Vertical synchronization signal 24 ... SECAM system demodulation part 25 ... PAL system demodulation part 26 ... NTSC system demodulation part 27 ... White balance adjustment part 30 ... Tuner 31 Antenna 32 CRT 33 Speaker 40 Microcomputer 41 White balance adjustment data 50 Composite video signal input terminal 60 EEPROM

Claims (10)

[Utility model registration claims] 1. PAL system, NTSC system and SECAM
A tuner that can input a television broadcast signal according to the system and selects a predetermined channel from a plurality of channels and outputs an intermediate frequency signal, and a composite that inputs a composite video signal from an external device through a predetermined connection terminal A video signal input unit, a one-chip IC that receives the intermediate frequency signal or the composite video signal and generates a video signal, a synchronization signal, and an audio signal; and a display that outputs a video based on the video signal and the synchronization signal. A white balance adjustment circuit for adjusting a white balance by controlling a cathode voltage and a grid voltage applied to the display; a speaker for outputting an audio based on the audio signal; and a control for an internal circuit of the television. To store various programs and various data An EEPROM; and a microcomputer for controlling the tuner, a one-chip IC, a white balance adjusting circuit, and an EEPROM based on various programs stored in the EEPROM. And the microcomputer stores white balance adjustment data for each broadcast system for each distinction. The one-chip IC determines whether the burst signal has a specific frequency or not, and determines whether or not the broadcasting method is the SECAM method based on whether or not the burst signal has a specific frequency. Determine whether the system is PAL system or NTSC system,
These determination results are output to the microcomputer, and the microcomputer refers to the EEPROM and controls the white balance adjustment circuit so as to adjust the white balance with white balance adjustment data that matches the determination result. Television. 2. PAL system, NTSC system and SECAM
Signal receiving means for receiving a television signal based on at least two broadcasting methods, and a predetermined video display on a picture tube based on the television signal received by the television signal receiving means. Video display means, broadcast method determination means for determining the broadcast method based on the television signal received by the television signal reception means, and broadcast determined by the broadcast method determination means by controlling the image display means A television comprising: a white balance adjusting unit that adjusts an image so that a white balance suitable for a system is obtained. 3. The broadcast system determination means determines whether the received television signal is a signal from a radio wave or obtained from an external device through a predetermined connection terminal, and the white balance adjustment means determines the received television signal based on the determination. 3. The television according to claim 2, wherein the video is adjusted so that a white balance suitable for both the radio wave and the one obtained from an external device via a predetermined connection terminal is obtained. John. 4. The broadcast system determination means according to claim 2, wherein the broadcast system determination means determines that the received television signal is the SECAM system when a burst signal of a constant frequency does not exist in the received television signal. The television according to any of the above. 5. The broadcast system determining means determines a frequency of a vertical synchronizing signal superimposed on the received television signal, and determines a PAL system and an NTS based on a difference in the frequency.
The television according to any one of claims 2 to 4, wherein the television is distinguished from the C system. 6. The video display means includes PLL means for performing stable oscillation in phase with a burst signal superimposed on the received television signal, and the broadcast system discriminating means comprises a lock in the PLL means. 5. The television according to claim 2, wherein the PAL system and the NTSC system are determined based on a difference in frequency. 7. The method according to claim 1, wherein the white balance adjustment unit refers to white balance adjustment data for each broadcasting system stored in a predetermined storage unit in advance to adjust the white balance for each broadcasting system. The television according to any one of claims 2 to 6, which performs the following. 8. The storage means stores white balance adjustment data for each broadcasting system for each of a television signal by radio waves and a television signal obtained from an external device via a predetermined connection terminal. The claim 2 wherein the balance adjusting means performs white balance adjustment according to a broadcasting system for each of a television signal by radio waves and a television signal obtained from an external device via a predetermined connection terminal. Item 7. A television according to Item 7. 9. The storage means further stores white balance adjustment data for each destination for each broadcasting system, and the white balance adjustment means refers to the destination data stored in a predetermined storage means at the time of shipment. 3. The method according to claim 2, wherein each of a television signal by radio waves and a television signal obtained from an external device via a predetermined connection terminal is adjusted according to a broadcasting system and white balance is adjusted according to a destination. The television according to claim 8. 10. PAL system, NTSC system and SECA
Receiving a television signal based on at least two or more broadcasting systems such as the M system, determining a broadcasting system based on the television signal, performing signal processing for each broadcasting system, and displaying a predetermined image on a picture tube. A television to be performed, comprising: a white balance adjusting unit that adjusts an image so as to obtain a white balance suitable for the determined broadcasting system when performing the signal processing.