JPH07111660A - Color television receiver - Google Patents

Abstract

PURPOSE:To obtain a receiver which is free from unnatural feeling even when a switch is performed between broadcasting programs of a high vision system and a standard television system by supplying a color temperature correction signal to a video signal processing circuit and correcting a color temperature when the conversion video signal from a down-converter circuit is selected. CONSTITUTION:When the signal of a MUSE system is received, a main microcomputer 10 controls a sound and video switch circuit 5 and switches to a state selecting the conversion video signal outputted from a down-converter circuit 4. A color temperature correction signal is supplied to a video processor 7 from the microcomputer 10 via the circuit 5. Thus, the color temperature is corrected and the difference of the color temperature generated between the conversion video signal and a standard video signal is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a down conversion for converting a high definition video signal band-compressed by a so-called MUSE system (multiple sub-Nyquist sampling system) into a standard television system video signal having an aspect ratio of 4: 3. The present invention relates to a color television receiver having a converter circuit.

[0002]

2. Description of the Related Art A high-definition television system has been developed as one of the higher-definition television systems than the NTSC system and the PAL system, but the standard is vertical frequency fV = 60Hz frame frequency fFR = fV / 2 horizontal. The frequency fH = 1125 x fFR = 33.75 kHz and the aspect ratio = 9:16.

Therefore, the video signal of the high-definition system has about 5 times the amount of information as compared with the video signal of the NTSC system, and the video signal of the high-definition system cannot be transmitted as it is by a broadcasting satellite, a video disc or the like.

Therefore, the high definition video signal is band-compressed by the so-called MUSE system so that the base band width becomes about 8 MHz and then transmitted. This MUSE method is basically dot interlaced transmission, and the sampling pattern is repeated in a 4-field cycle with offsets between frames, between fields, and between lines.

In the MUSE system, the video signal (luminance signal and color signal) and the quasi-instantaneous companding DPCM are used.
Audio data encoded by the method and an independent additional information signal are multiplexed on the time axis. However, MU
Even in the high definition video signal band-compressed by the SE system, the frame frequency and the horizontal frequency are
It is equal to the frame frequency fFR and horizontal frequency fH of the original high definition video signal.

As described above, a high-definition video signal band-compressed by the MUSE system (hereinafter referred to as MUS
The E standard video signal) has a completely different signal standard from the standard television standard video signal.

In order to faithfully display a color image by receiving the above-mentioned MUSE type video signal by a standard television type, for example, an NTSC type color television receiver, the MUSE type video signal conforms to the NTSC type. It is necessary to convert the video signal into a video signal.

Therefore, a color television receiver provided with a down converter circuit for converting the video signal of the MUSE system into a video signal compatible with the NTSC system is provided. This color television receiver is a color television receiver capable of receiving both MUSE and NTSC television signals and capable of faithfully displaying an image by either video signal.

[0009]

SUMMARY OF THE INVENTION However, the inventors of the present invention have found that an image of a high-definition broadcast program being viewed on the above-mentioned color television receiver and N
It was discovered that the color temperature of the image is different from the image when viewing the TSC broadcast program.

Therefore, the color temperature of the image displayed on the screen is changed when the viewing of the high-definition program is switched to the viewing of the NTSC broadcast program, or vice versa. There is a problem that the viewer feels uncomfortable due to the difference.

In view of the above points, the present invention reduces the difference in color temperature that occurs in an image when a high-definition broadcast program is viewed and when an NTSC broadcast program is viewed.
An object of the present invention is to provide a color television receiver that prevents viewers from feeling uncomfortable even when switching between a high-definition broadcast program and an NTSC broadcast program.

[0012]

As a result of investigating the cause by the inventor of the present invention, there is a problem in an IC used in a down converter circuit for converting a video signal of the MUSE system into a video signal conforming to the standard television system. I found something. In this invention, the color temperature is corrected in the video signal processing circuit without depending on the down converter circuit.

That is, when the reference numerals of the embodiment shown in FIG. 1 to be described later are made to correspond to each other, according to the present invention, a display element 9 for displaying a color image and a high-definition type video signal band-compressed by the MUSE method have an aspect ratio. A down converter circuit 4 for converting into a 4: 3 standard television system video signal (hereinafter referred to as a standard video signal), the standard video signal, and a video signal from the down converter circuit 4 (hereinafter referred to as a converted video signal). Switching circuit 5 for selecting switching, a video signal processing circuit 7 for receiving the output signal from the switching circuit 5 and forming a signal for driving the display element 9, and a switching control signal for the switching circuit 5. Of the control circuit 10 and the switching circuit 5 for selecting the converted video signal from the down converter circuit 4. To come, the video signal processing circuit 7 to the color temperature correction signal supplied color temperature correction signal supplying means 19
With the color temperature correction signal, it is possible to reduce the difference in color temperature between when an image is displayed by the standard video signal and when an image is displayed by the converted video signal.

[0014]

When the MUSE type signal is received, the control circuit 10 controls the switching circuit 5 by the switching control means to switch the conversion video signal output from the down converter circuit 4 to the selected state. Then, the color temperature correction signal is supplied to the video signal processing circuit 7 by the color temperature correction signal supply means 19.

When the converted video signal is supplied to the video signal processing circuit 7 via the switching circuit 5, the color temperature is corrected by the color temperature correction signal. This reduces the difference in color temperature between the converted video signal and the standard video signal.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the color television receiver according to the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram of an embodiment of a color television receiver according to the present invention. UHF / VH
The F tuner 1 selects a channel under the control of the main microcomputer 10, demodulates the NTSC video signal V and the left and right channel audio signals L and R, and outputs them to the audio / video switch circuit 5.

Further, the CS / BS tuner 2 is
Channel selection is performed under the control of the BS microcomputer 3, and when the video signal is the NTSC system, the video signal V and the left and right channel audio signals L and R are demodulated and output to the audio / video switch circuit 5. In addition, CS / BS tuner 2
When the received video signal is in the MUSE format, the video detection output and the audio detection output are output to the MUSE / NTSC down converter 4 (hereinafter referred to as the M / N down converter 4). The M / N down converter 4 decodes the input MUSE video signal, and at the same time, processes a luminance signal Y and a color signal C compatible with the NTSC system.
Convert to.

At this time, the CS / BS microcomputer 3 determines that the MU
Information indicating reception of the SE system video signal is sent to the main microcomputer 10 described later. Then, the M / N down converter 4 outputs the converted luminance signal Y, color signal C, and left and right channel audio signals L and R to the audio / video switch circuit 5. CS / BS microcomputer 3, M / N down converter 4
Are controlled by the main microcomputer 10.

The audio / video switch circuit 5 is controlled by the main microcomputer 10, and the converted video signal output from the M / N down converter 4 and the NTSC system video signal (from the UHF / VHF tuner 1 or the CS / BS tuner 2 ( (Hereinafter referred to as a received NTSC video signal).

Then, the audio / video switch circuit 5 has a UH
When the NTSC video signal received from the F / VHF tuner 1 or the CS / BS tuner 2 is selected, the output video signal V from the audio / video switch circuit 5 is supplied to the Y / C separation circuit 6. The Y / C separation circuit 6 is
Input N controlled by main microcomputer 10
The TSC video signal V is separated into a luminance signal Y and a color signal C and returned to the audio / video switch circuit 5. Then, the returned luminance signal Y and color signal C are supplied to the video processor 7.

When the audio / video switch circuit 5 selects the converted video signal from the M / N down converter 4, the output video signal V is not derived and the converted video signal output from the M / N down converter 4 is not derived. Luminance signal Y of
The color signal C is directly supplied to the video processor 7.

The video processor 7 is controlled by the main microcomputer 10 and the inputted luminance signal Y and color signal C are inputted.
From the three primary color signals R, G, for driving the cathode ray tube 9.
Generate B.

The video processor 7 has a function of correcting the color temperature, and the user can operate the key 17 or the remote controller 18 to correct the color temperature and adjust the reproduced image to a desired color temperature. Information for adjusting the color temperature is supplied from the main microcomputer 10 to the video processor 7 in response to key input or remote control input.

The main microcomputer 10 also outputs information indicating the reception of the MUSE signal when the CS / BS tuner 2 is selected and the MUSE system high-definition signal is received regardless of key input or remote control input. CS
/ Received from BS microcomputer 3, audio / video switch circuit 5
A switching control signal for taking out the converted video signal from the M / N down converter 4 as its output, and receiving the image by the converted video signal and the reception NTSC from the UHF / VHF tuner 1 or the CS / BS tuner 2
The color temperature correction information CT for correcting the difference in color temperature between the video signal and the image is sent to the video processor 7.

The color temperature correction information CT is stored in advance in the memory of the main microcomputer 10. The operation of the main microcomputer 10 here will be described below with reference to FIG.

When the CS / BS tuner 2 receives the MUSE type video signal by the viewer's channel selection,
Information from the / BS microcomputer 3 is transmitted to the main microcomputer 10. When the main microcomputer 10 determines that it has received the information indicating that the received video signal is a MUSE video signal (step 20).
1), a switching control signal for switching to the output side of the M / N down converter 4 is transmitted to the audio / video switch circuit 5,
The audio / video switch circuit 5 is switched (step 20).
2). Next, the main microcomputer 10 supplies the color temperature correction information CT to the video signal processing circuit 7 in order to correct the color temperature difference between the reproduced images of the converted video signal and the video signal of the NTSC system (step). 203).

The cathode ray tube 9 emits the corresponding three primary color beams by the three primary color signals R, G, B supplied as described above, and scans them in the horizontal and vertical directions by the deflection signal from the deflection circuit 12, Reproduce the image.

The audio signals L and R from the audio / video switch circuit 5 are supplied to the audio processor 13. The audio processor 13 receives the control of the main microcomputer 10 and receives the sound signals L and R with respect to the volume,
Adjust the balance and sound quality, and output the adjusted signal. Then, the output signal is amplified by the voice amplifier 14 and the voice is output from the speaker 15.

The sync separation circuit 8 separates and obtains the horizontal sync signal HD and the vertical sync signal VD from the luminance signal Y from the audio / video switch circuit 5. These synchronization signals HD and VD are
It is supplied to the frame microcomputer 11 and is also supplied to the deflection circuit 12.

The frame microcomputer 11 is controlled by the main microcomputer 10. Then, the frame microcomputer 11 is supplied with the control information from the main microcomputer 10 and the horizontal synchronizing signal HD and the vertical synchronizing signal VD from the sync separation circuit 8, and generates a blanking signal BLK according to the display mode.
Then, it outputs to the video processor 7 via the adder circuit 20.

The main microcomputer 10 uses the three primary color signals R for displaying characters such as a channel number and a voice multiplex mode.
G and B are generated and supplied to the video processor 7 via the adder circuit 20.

The deflection circuit 12 is controlled by the main microcomputer 10 and generates a deflection signal. This deflection signal is supplied to the deflection yoke DY of the cathode ray tube 9.

The memory 16 stores information required by the main microcomputer 10 for each control.

The main microcomputer 10 is supplied with operation input information by the user from the keys 17 and the remote controller 18. The operation input information includes tuning information, volume adjustment information, and color temperature adjustment information for adjusting to a desired color temperature.

The cathode ray tube 9 of the color television receiver 100 of this embodiment has a so-called horizontally wide screen with an aspect ratio of 9:16. The color television receiver of this example includes a frame microcomputer 11 and a deflection circuit 12.
Thus, the blanking position, scanning speed, and deflection width are controlled so that an image can be displayed in several display modes such as a normal display mode, a wide display mode, and a zoom display mode.

The operation of receiving a broadcast signal and reproducing an image in the color television receiver of the embodiment having the above configuration will be described below.

When the viewer operates the key 17 or the remote controller 18 to receive the broadcast signal by the UHF / VHF tuner 1, the operation information input by the viewer is:
The tuning signal is supplied to the main microcomputer 10, decoded by the main microcomputer 10, and a tuning signal is formed. The tuning signal is supplied to the UHF / VHF tuner 1.

In the UHF / VHF tuner 1, tuning is performed based on the tuning information from the main microcomputer 10.
An NTSC television signal of a desired channel is received. Then, in the UHF / VHF tuner 1, the video signal V and the left and right channel audio signals L and R are demodulated and supplied to the audio / video switch circuit 5.

The audio / video switch circuit 5 is controlled by the main microcomputer 10 and selects the output from the UHF / VHF tuner 1, and the video signal V is the Y / C separation circuit 6
Has been switched to supply.

Therefore, the video signal V supplied from the UHF / VHF tuner 1 to the audio / video switch circuit 5 is
It is supplied to the Y / C separation circuit 6, and when it is separated into the luminance signal Y and the color signal C, it is returned to the audio / video switch circuit 5. Then, the separated luminance signal Y and color signal C are supplied from the audio / video switch circuit 5 to the video processor 7, and in the video processor 7, the three primary color signals R, G, B are supplied.
Are formed and supplied to the cathode ray tube 9. In the cathode ray tube 9, a color image is reproduced by the supplied three primary color signals R, G and B.

When the viewer operates the key 17 or the remote controller 18 to receive the broadcast signal by the CS / BS tuner 2, the operation information input by the viewer is supplied to the main microcomputer 10, and the main microcomputer 10 is supplied. A channel selection signal is formed while being decoded by 10, and this control signal is supplied to the BS / CS microcomputer 3. And C
Under the control of the S / BS microcomputer 3, the CS / BS tuner 2 tunes in to receive the desired broadcast channel.

At this time, if the broadcast signal of the received channel is a television signal of the NTSC system, the NT received by the UHF / VHF tuner 1 described above.
The same processing as the SC television signal is performed, and a color image is reproduced on the screen of the cathode ray tube 9.

On the other hand, when the broadcast signal of the channel received by the CS / BS tuner 2 is a high definition signal of the MUSE system, the CS / BS microcomputer 3 instructs the main microcomputer 10 to send a television of the MUSE system. Information is received that a signal has been received. Further, by the control of the CS / BS microcomputer 3, the video detection output and the audio detection output from the CS / BS tuner 2 are M / N.
It is supplied to the down converter 4.

Based on the MUSE type television signal reception information from the CS / BS microcomputer 3 from the main microcomputer 10, the M / N is sent to the audio / video switch circuit 5.
A switching signal for selecting the output from the down converter 4 is supplied. Furthermore, from the main microcomputer 10,
A color temperature correction signal CT for correcting a difference in color temperature between an image produced by a converted video signal of the MUSE system output from the / N down converter 4 and an image produced by a video signal of the MTSC system is supplied to the video processor 7. To be done.

Then, in the M / N down converter 4,
From the supplied MUSE video detection output, NTSC
It is converted into a converted video signal including a luminance signal Y and a color signal C conforming to the method. Luminance signal Y of this converted video signal
The color signal C and the color signal C are directly supplied to the video processor 7 through the audio / video switch circuit 5.

In the video processor 7, the color temperature correction information CT supplied from the main microcomputer 10 is used to correct the color temperature of the converted video signal.
Then, in the video processor 7, the difference in color temperature generated between the image by the converted video signal of the MUSE system and the image by the video signal of the NTSC system is corrected 3.
Primary color signals R, G, G are formed. Then, this is supplied to the cathode ray tube 9, and the cathode ray tube 9 reproduces an image whose color temperature is corrected.

Therefore, for example, from the state where the CS / BS tuner 2 receives and watches the television signal of the NTSC system, the program broadcast next on the same channel is replaced with the high-definition broadcast of the MUSE system. Even when it happens, the above-mentioned CS / BS microcomputer 4 notifies the main microcomputer 10 that the high-definition broadcasting of the MUSE system has been changed, and the color temperature correction is automatically performed, so that the viewer feels uncomfortable. Never. The same applies when switching is performed in reverse.

It should be noted that for both the image projected by the NTSC system video signal and the color temperature corrected image projected by the MUSE system converted video signal, the key 1 is pressed.
By operating 6 or the remote controller 17, it is possible to adjust the color temperature to a viewer's favorite color temperature.

In this embodiment, the CS / BS microcomputer 3 confirms that the video signal supplied to the television receiver is a MUSE type video signal.
0, and the main microcomputer 10 automatically supplies the color temperature correction signal to the video processor-7.
It is also possible to control the remote controller 18 to manually execute the color temperature correction.

[0051]

As described above, according to the present invention, the image of the converted video signal of the MUSE system and the image of the video signal of the NTSC system converted into the video signal compatible with the NTSC system by using the down converter circuit. It is possible to correct the difference in the color temperature that occurs between and without depending on the converter circuit.

Moreover, the control circuit judges that the MUSE video signal has been supplied to the television receiver,
The color temperature can be automatically corrected. Therefore, the viewer does not feel uncomfortable.

[Brief description of drawings]

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

FIG. 2 is a diagram illustrating a flow of color temperature correction processing of an embodiment of a television receiver according to the present invention.

[Explanation of symbols]

 1 UHF / VHF tuner 2 CS / BS tuner 3 CS / BS microcomputer 4 M / N down converter 5 Audio / video switch circuit 6 Y / C separation circuit 7 Video processor 9 Cathode ray tube 10 Main microcomputer 16 Memory 17 Key 18 Remote control 19 Data bus

Claims (2)

[Claims] 1. A color display device for displaying a color image, and a high-definition video signal band-compressed by a multiple sub-Nyquist sampling method, with an aspect ratio of 4:
3, a down converter circuit for converting into a standard television system video signal, a switching circuit for selecting between the standard television system video signal and the video signal from the down converter circuit, and an output from the switching circuit. A video signal processing circuit which receives a signal and forms a signal for driving the color display element, a control circuit which forms a switching control signal of the switching circuit, and a video signal from the down converter circuit is selected by the switching circuit. In this state, a color temperature correction signal supply means for supplying a color temperature correction signal to the video signal processing circuit is provided, and an image is displayed by the standard television system video signal by the color temperature correction signal. Time and the image is displayed by the video signal converted by the down converter circuit. Color television receiver so as to reduce the difference between the color temperature at the time was. 2. The color television receiver according to claim 1, wherein the standard television system is an NTSC system and has a screen with an aspect ratio of 16: 9.