JPH06303549A - Television receiver - Google Patents

Abstract

PURPOSE:To video-display by automatically switching and selecting a luminance signal and a chrominance signal from a luminance signal input terminal and a chrominance signal input terminal connected to a MUSE-NTSC converter when a satellite broadcast signal of MUSE system is received. CONSTITUTION:Since the luminance signal n1Y from the MUSE-NTSC converter 31 goes to a signal when the satellite signal of MUSE system is received, the output of a luminance signal detection circuit 12 goes to a high level, and an AV switch circuit 6 selects the luminance signal input terminal and the chrominance signal input terminal. Thereby, the luminance signal and the chrominance signal from the luminance signal input terminal and the chrominance signal input terminal connected to the MUSE-NTSC converter can be video-displayed by automatically switching and selecting when the satellite broadcast signal of MUSE system is received.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scrambled broadcast decoder and a television receiver to which the S-terminal of a MUSE-NTSC converter can be connected, and more particularly to a MUSE in a state where color signals and luminance signals do not interfere much.
The present invention relates to a television receiver capable of simplifying an operation when receiving a signal.

[0002]

2. Description of the Related Art With the establishment of satellite broadcasting (hereinafter referred to as BS broadcasting), television receivers incorporating a satellite broadcasting receiving circuit (hereinafter referred to as BS receiving circuit) are becoming popular. 2. Description of the Related Art In recent years, a television receiver having a built-in BS receiver circuit has a scrambled broadcast decoder for viewing scrambled broadcasts in BS broadcasts and a MUSE-NTS for viewing MUSE satellite broadcasts (defeated vision broadcasts).
There is one that allows a C converter to be connected.

FIG. 3 is a block diagram showing such a conventional television receiver.

In FIG. 3, reference numeral 51 is a television receiver, and the television receiver 51 is connected with a first converter 72, a MUSE-NTSC converter 81 and a scramble broadcast decoder 91.

A high frequency signal from the satellite is received by a parabolic antenna 71, converted into a BS intermediate frequency signal a2 by a first converter, and the B of the television receiver 51 is converted.
It is led to the SIF input terminal 52.

The BS intermediate frequency signal a2 guided to the BSIF input terminal 52 is supplied to the BS receiving circuit 53.

The BS receiving circuit 53 has a BSIF input terminal 5
The BS intermediate frequency signal a2 from 2 is tuned and FM detected to create an FM detected signal b2, which is guided to the FM detected output terminal 54 provided on the cabinet back plate of the television receiver 51, and also an audio digital signal is output. A bitstream signal c2 including a signal and related information is led to a bitstream output terminal 55 provided on the back plate of the television receiver 51. The BS reception circuit 53 also performs video signal processing and audio signal processing of the FM detection signal b2,
The C-system composite video signal d2 and audio signal e2 are created and supplied to the first video and audio signal input terminal of the audiovisual switch circuit (hereinafter referred to as AV switch circuit) 56. Further, the BS reception circuit 53 is connected to the automatic frequency control signal input terminal (AFC signal input terminal) 57 to A provided on the cabinet rear plate of the television receiver 51.
When the FC signal f2 is supplied, the local oscillation frequency is controlled based on the AFC signal f2 to perform tuning. Further, the BS reception circuit 53 detects whether or not the scrambling is performed by detecting the control information of the bit stream signal, creates the switch control signal g2 based on the result of this determination, and outputs it to the AV switch circuit 56. Supply.

The FM detection output terminal 54 is connected to the FM detection input terminal of the MUSE-NTSC converter 81 via a connection cord.

The bit stream output terminal 55 is connected to the bit stream input terminal of the scramble broadcast decoder 91 via a connection code.

As a result, the FM detection signal b2 and the bit stream signal c2 output by the BS reception circuit 53 are supplied to the MUSE-NTSC converter 81 and the scramble broadcast decoder 91, respectively.

The MUSE-NTSC converter 81 detects whether the supplied FM detection signal b2 is the MUSE system or the NTSC system. When the FM detection signal b2 is not the MUSE system, the FM detection signal b2 is set as the FM detection signal h2. It is supplied to the scramble decoder 91.

The scramble broadcast decoder 91 detects whether or not scramble is performed by detecting the control information of the bit stream signal c2. When the scramble broadcast decoder 91 detects that the scramble is performed, the scramble broadcast decoder 91 creates a scramble signal by performing video signal processing of the FM detection signal h2 from the MUSE-NTSC converter 81, and the scramble signal is generated. The video signal i2 is created by descrambling using the related information of the signal c2, and the audio signal j2 is also descrambling and digital / analog (D / A) converted from the audio digital signal of the bitstream signal c2. And the created video signal i2 and audio signal j2 are MUSE-NT
It leads to the SC converter 81. When the scramble broadcast decoder 91 detects that the scramble is not performed, the scramble broadcast decoder 91 creates the video signal i2 by performing the video signal processing without descrambling the FM detection signal h2. An audio signal j2 is created by performing D / A conversion of the audio digital signal without descrambling the bit stream signal c2, and the created video signal i2 and audio signal j2 are converted into M
It leads to the USE-NTSC converter 81.

The MUSE-NTSC converter 81 has an F
When the M detection signal b2 is not the MUSE system, the video signal i2 and the audio signal j2 from the scramble broadcast decoder 91 are converted into the video signal k2 and the audio signal m2 from the BS output terminal via the connection cord to the BS of the television receiver 51. In addition to being guided to the input terminal 58, a no-signal is sent from the luminance signal output terminal and the color signal output terminal of the S terminal to the luminance signal input terminal 59Y and the color signal input terminal 59C of the S terminal 59 of the television receiver 1 through a connection cord. Guide each.

Further, the MUSE-NTSC converter 81
If the FM detection signal b2 is of the MUSE system,
An AFC signal (automatic frequency control signal) f2 is created based on the detection signal b2 and is guided to the AFC input terminal 57 of the television receiver 51. Further, when the MUSE-NTSC converter 81 detects that the FM detection signal b2 is in the MUSE system, the MUSE-system FM detection signal b2 is detected.
Is converted into digital data once, the digital data is subjected to non-linear processing, data is interpolated using the data in the field, the scanning line is converted to the NTSC system, and the luminance signal data and the color signal data are created and created. The luminance signal data and the color signal data are converted into analog luminance signal n2Y and color signal n2C, respectively, and the S signal of the television receiver 51 is transmitted from the luminance signal output terminal and the color signal output terminal of the S terminal through a connection cord. Luminance signal input terminal 5 of terminal 59
9Y and color signal input terminal 59C, respectively. Also, M
The USE-NTSC converter 81 uses the FM detection signal b2.
Is a MUSE method, an analog luminance signal n2Y
The NTSC system video signal is created from the color signal n2C and the color signal n2C, and the audio signal is created by performing the audio signal processing of the FM detection signal b2. The audio signal is created as the video signal k2 and the audio signal m2 from the BS output terminal through the connection cord. To the BS input terminal 58 of the television receiver 51.

Video signal k2 led to the BS input terminal 58
And the audio signal m2 are supplied to the second video and audio signal input terminal of the AV switch circuit 56. The brightness signal n2Y and the color signal n2C led to the brightness signal input terminal 59Y and the color signal input terminal 59C are supplied to the brightness signal input terminal and the color signal input terminal of the AV switch circuit 56, respectively. The AV switch circuit 56 has a BS input terminal 58.
Whether or not a connection cord is connected to the input terminal selection mode by key input and the BS reception circuit 53
The input terminal is selected based on the switch control signal g2 from.

More specifically, the AV switch circuit 56 detects that the connection code is not connected to the BS input terminal 58, and the switch control signal g2 from the BS reception circuit 53 is not scrambled. In the case shown, the video signal d2 and the audio signal e2 from the BS receiving circuit 53 are supplied to the video display circuit 60 and the audio output circuit 61 as the video signal p2 and the audio signal q2. Also, the AV switch circuit 56 detects that the connection code is not connected to the BS input terminal 58, and when the switch control signal g2 from the BS reception circuit 53 indicates that scrambling is performed, the BS The no signal from the input terminal 58 is supplied to the video display circuit 60 and the audio output circuit 61. Further, the AV switch circuit 56 detects that the connection cord is connected to the BS input terminal 58, and when the setting of the input terminal selection mode by the key input is the automatic selection mode, the AV input circuit 58 outputs from the BS input terminal 58. Video signal k
2 and the audio signal m2 are supplied to the video display circuit 60 and the audio output circuit 61 as the video signal p2 and the audio signal q2. Further, the AV switch circuit 56 has the BS input terminal 5
When it is detected that the connection cord is connected to the input terminal 8 and the setting of the input terminal selection mode by key input is the S terminal selection mode, the luminance signal input terminal 59 of the S terminal 59 is detected.
The luminance signal n2Y and the color signal n2C from the Y and color signal input terminals 59C are supplied to the video display circuit 60 as the luminance signal p2Y and the color signal p2C from different wirings, and the audio signal m2 from the BS input terminal 58 is an audio signal. q
2 is supplied to the audio output circuit 61.

When the video signal p2 is supplied, the video display circuit 60 creates a luminance signal and a color signal from the video signal p2, and creates three primary color signals from the created luminance signal and color signal. The image is displayed on the CRT. When the luminance signal p2Y and the color signal p2C are supplied, the image display circuit 60 creates three primary color signals from the luminance signal p2Y and the color signal p2C and displays the image on the cathode ray tube. The audio output circuit 61 outputs the supplied audio signal q2 to audio output means such as a speaker.

In such a conventional television receiver, when a normal BS broadcast signal is received without connecting a connecting cord to the BS input terminal 58, the NTSC composite video signal d2 from the receiving circuit 53 is received. And the audio signal e2 is supplied to the video display circuit 60 and the audio output circuit 61 via the AV switch circuit 56, and video display and audio output are performed.

In the automatic selection mode, when a connection cord is connected to the BS input terminal 58 to receive ordinary BS broadcast, scrambled broadcast and high-definition broadcast,
Video signal k2 from MUSE-NTSC converter 81
And the audio signal m are supplied to the video display circuit 60 and the audio output circuit 61 via the AV switch circuit 56, and video display and audio output are performed.

Here, when the high-definition broadcast is received in the automatic selection mode, since the color signal and the luminance signal are transmitted on the same line as the combined video signal k2, the color signal and the luminance signal interfere with each other. Therefore, the original performance of HDTV cannot be demonstrated. Therefore, when a high-definition broadcast is received in a state where the color signal and the luminance signal do not interfere much, the automatic selection mode is switched to the S terminal selection mode by the key operation, and the separated luminance signal p2Y from the MUSE-NTSC converter 81 is generated. The color signal p2C is supplied to the video display circuit 60 via the AV switch circuit 56. For this reason, when receiving a high-definition broadcast in a state where the color signal and the luminance signal do not interfere so much, it is necessary to perform a channel selection operation and a switching to the S terminal selection mode, which results in poor operability. Was becoming.

[0021]

In the above-described conventional television receiver, when the MUSE signal is received in a state where the color signal and the luminance signal do not interfere much with each other, the mode in which the BS input terminal is selected by the key operation is selected. To a mode for selecting the luminance signal input terminal and the color signal input terminal of the S terminal, and supplying the separated luminance signal and color signal from the MUSE-NTSC converter to the video display circuit via the AV switch circuit. There is. Therefore, when the MUSE signal is received in a state where the color signal and the luminance signal do not interfere so much, it is necessary to perform a channel selection operation and a switch to the S terminal selection mode, which results in poor operability. It was

Therefore, the present invention automatically switches the luminance signal and the color signal from the luminance signal input terminal and the color signal input terminal connected to the MUSE-NTSC converter when receiving the MUSE satellite broadcast signal. An object of the present invention is to provide a television receiver capable of selectively displaying an image.

[0023]

SUMMARY OF THE INVENTION A television receiver according to the present invention includes a satellite broadcast receiving circuit that outputs an FM detection signal and a bit stream signal by receiving a satellite broadcast signal, and an FM from the satellite broadcast receiving circuit. The detection signal is guided to the scrambled broadcast decoder and MUSE-NTSC.
The FM detection output terminal connected to the FM detection input terminal of the converter via the connection cord and the bit stream signal from the satellite broadcast reception circuit are guided and connected to the bit stream input terminal of the scrambled broadcast decoder via the connection cord. A bit stream output terminal connected thereto, a satellite broadcast input terminal connected to a video signal output terminal of the scrambled broadcast decoder via a connection cord, and the MU
A luminance signal input terminal connected to a luminance signal output terminal of the SE-NTSC converter via a connecting cord;
A luminance signal and a color signal are created from a color signal input terminal connected to a color signal output terminal of the SE-NTSC converter via a connection cord and a video signal from the satellite broadcast input terminal, and the created luminance signal and color signal An image display circuit that creates a signal for display from the image signal and displays the image, and creates a signal for display from the luminance signal from the luminance signal input terminal and the color signal from the color signal input terminal to display the image. When,
A brightness signal detection circuit for detecting the presence or absence of a brightness signal from the brightness signal input terminal, a video signal from the satellite broadcast input terminal, a brightness signal from the brightness signal input terminal, and a color signal input terminal in the video display circuit. If the detection result of the luminance signal detection circuit is not provided, the video signal from the satellite broadcast input terminal is guided to the video display circuit, and the detection result of the luminance signal detection circuit is In the case where it is present, a switch circuit for guiding a luminance signal from the luminance signal input terminal and a color signal from the color signal input terminal to the video display circuit is provided.

[0024]

According to this structure, when the satellite broadcast receiving circuit receives the MUSE satellite broadcast signal, the MU
The brightness signal is output from the brightness signal output terminal of the SE-NTSC converter, the detection result of the brightness signal detection circuit becomes valid, and the switch circuit displays the brightness signal from the brightness signal input terminal and the color signal from the color signal input terminal to the video display circuit. Therefore, when the MUSE satellite broadcasting signal is received, M
It is possible to automatically switch and select the luminance signal and the color signal from the luminance signal input terminal and the color signal input terminal connected to the USE-NTSC converter to display an image.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments.

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

In FIG. 1, reference numeral 1 is a television receiver having an Aspect ratio of 4: 3 on the screen of a CRT.
This television receiver 1 has a first converter 22, M
The USE-NTSC converter 31 and the scramble broadcast decoder 41 are connected. Here, the parabolic antenna 31, the first converter 22, the MUSE-NTSC converter 31, and the scramble broadcast decoder 41 are the parabolic antenna 71, the first converter 72, and the MU of FIG.
The SE-NTSC converter 81 and the scramble broadcast decoder 91 are exactly the same.

The high frequency signal from the satellite is received by the parabolic antenna 21, converted into the BS intermediate frequency signal a1 by the first converter 22, and guided to the BSIF input terminal 2 of the television receiver 1.

The BS intermediate frequency signal a1 guided to the BS input terminal 2 is supplied to the BS receiving circuit 3.

The BS receiver circuit 3 tunes to the BS intermediate frequency signal a1 from the BS input terminal 2 and performs FM detection to create an FM detection signal b1 to produce the television receiver 1
Of the TV receiver 1 and the FM detection output terminals 4 and 14 provided on the back plate of the cabinet, and the bit stream signal c1 including the audio digital signal and related information is provided on the back plate of the television receiver 1. Lead to. Further, the BS receiving circuit 3 receives the FM detection signal b1.
The video signal processing and the audio signal processing are performed to create the NTSC video signal d1 and the audio signal e1 and supply them to the first video and audio signal input terminal of the AV switch circuit 6. Further, the BS receiving circuit 3 has an AFC signal input terminal 7
When the AFC signal f1 is supplied, the local oscillation frequency is controlled on the basis of the AFC signal f1 to perform tuning. Further, the BS receiving circuit 3 detects whether or not the scrambling is performed by detecting the control information of the bit stream signal, and creates the first switch control signal g1 based on the result of this determination to generate the AV switch. Supply to the circuit 6.

The FM detection output terminal 14 is a MUSE-NT.
It is connected to the FM detection input terminal of the SC converter 31.
The FM detection output terminal 4 is used for the scramble broadcast decoder 41.
Connected to the FM detection input terminal of. The bit stream output terminal 5 is connected to the FM detection input terminal of the scramble broadcast decoder 41.

As a result, the F output from the BS receiving circuit 3
The M detection signal b1 is supplied to the MUSE-NTSC converter 31 and the scramble broadcast decoder 41.

The scramble broadcast decoder 41 detects whether or not the scramble is performed by detecting the control information of the bit stream signal c1. When the scramble broadcast decoder 41 detects that scrambling is performed, the scramble broadcast decoder 41 performs a video signal processing of the FM detection signal b1 from the FM detection output terminal 4 to create a scramble signal. , The video signal i1 is created by descrambling using the related information of the bitstream signal c1, and the descrambling and digital / digital scrambling of the audio digital signal are performed on the bitstream signal c1.
Analog (D / A) conversion is performed to create a voice signal j1,
The created video signal i1 and audio signal j1 are transmitted to the BS.
It leads to the input terminal 8. Also, the scramble broadcast decoder 4
In No. 1, when it is detected that the scramble is not performed, the video signal i1 is created by performing the video signal processing without descrambling the FM detection signal b1, and the FM signal b1 is converted into the bit stream signal c1. On the other hand, D / of the audio digital signal without descrambling
A conversion is performed to generate an audio signal j1, and the created video signal i1 and audio signal j1 are guided to the BS input terminal 8.

The video signal i1 and the audio signal j1 guided to the BS input terminal 8 are supplied to the second video and audio signal input terminal of the AV switch circuit 6.

The MUSE-NTSC converter 31 can be switched between a squeeze mode and a letterbox mode by switching a switch. The squeeze mode is a mode in which an image with a normal aspect ratio can be displayed on the entire screen when displaying 525 scanning lines on a television receiver having a screen with an aspect ratio of 16: 9. Letterbox mode has an aspect ratio of 4: 3
In the case of displaying 525 scanning lines on the television receiver of the above screen, 1/8 of the upper side and 1 of the lower side of the 525 scanning lines are displayed.
In this mode, the / 8 part is used as a blank part and an image with a normal aspect ratio is displayed on the screen in the 3/4 part of the center of the screen.

The MUSE-NTSC converter 31 has an F
If the M detection signal b1 is not in the MUSE system, no signal is output from the luminance signal output terminal of the S terminal and the chrominance signal output terminal through the connection cord to the luminance signal input terminal 9Y of the S terminal 9 of the television receiver 1. To the color signal input terminal 9C.

In addition, the MUSE-NTSC converter 31
If the FM detection signal b1 is of the MUSE system,
An AFC signal (automatic frequency control signal) f1 is created based on the detection signal b1 and guided to the AFC input terminal 7 of the television receiver 1. In addition, MUSE-NTSC converter 3
In the case of detecting that the FM detection signal b1 is in the MUSE system, the data No. 1 temporarily converts the MUSE system FM detection signal b1 into digital data, and performs a non-linear processing on the digital data, and uses the data in the field to perform data processing. Interpolation is performed, and thereafter, in the case of the squeeze mode, the scanning lines are thinned out to convert the scanning lines into 525 lines, and in the case of the delay box mode, the scanning lines are thinned out and 525 scanning lines are divided into 3/4. Then, 525 scanning lines are created by inserting 525 scanning lines in the upper and lower sides into 525 scanning lines, and luminance signal data and color signals are generated from the data of the 525 scanning lines thus created. Data is created, and the created brightness signal data and color signal data are converted into analog brightness signals and color signals, respectively. By superimposing a DC voltage, the luminance signal n1
The Y and color signals n1C are output from the luminance signal output terminal and the color signal output terminal of the S terminal, respectively. MUSE-NTS
The luminance signal n1Y and the color signal n1C respectively output from the luminance signal output terminal and the color signal output terminal of the S terminal of the C converter 31 are the luminance of the S terminal 9 of the television receiver 1 via individual connection cords. It is led to the signal input terminal 9Y and the color signal input terminal 9C, respectively. Also, MUS
In the E-NTSC converter 31, the FM detection signal b1 is M
In the case of the USE system, an NTSC system video signal is created from the above-described analog luminance signal and color signal, and an audio signal is created by performing audio signal processing of the FM detection signal b1. The audio signal m1 is guided from the BS output terminal to the second BS input terminal 18 of the television receiver 1 via the connection cord.

Video signal k1 led to BS input terminal 18
And the audio signal m1 are supplied to the third video and audio signal input terminal of the AV switch circuit 6. The brightness signal n1Y and the color signal n1C led to the brightness signal input terminal 9Y and the color signal input terminal 9C are supplied to the brightness signal input terminal and the color signal input terminal of the AV switch circuit 6, respectively, and the brightness signal detection circuit 12 is also supplied. And squeeze signal detection circuit 1
3 is supplied.

The luminance signal detection circuit 12 is arranged to detect the luminance signal n1Y.
It is detected whether the luminance signal n1Y has a signal or no signal by detecting the sync tip of the signal, and when the detection result is a signal, the high-level detection signal r1 is supplied to the anode of the diode D1 and no detection result is obtained. In the case of a signal, the low level detection signal r1 is supplied to the anode of the diode D1.

The squeeze detection circuit 13 outputs the color signal n1C.
The presence or absence of the squeeze discrimination signal superimposed on is detected, and when the detection result is present, the high-level detection signal s1 is supplied to the vertical amplitude switching circuit 15 and the anode of the diode D2. Supplies the low-level detection signal s1 to the vertical amplitude switching circuit 15 and the anode of the diode D2.

The vertical amplitude switching circuit 15 detects the detection signal s1.
Is low level, the horizontal and vertical deflection signals for normal scanning are supplied to the cathode ray tube having an aspect ratio of 4: 3, and when the detection signal s1 is high level, the amplitude of the vertical deflection signal is Is compressed to 3/4, and the aspect ratio is 1 for a CRT with a screen aspect ratio of 4: 3.
It supplies horizontal and vertical deflection signals for a 6: 9 scan.

The anodes of the diodes D1 and D2 are commonly connected at a connection point A1, and the voltage at this connection point A1 is used as the second switch control signal t1 for the second switching of the AV switch circuit 6.
Is supplied to the switch control signal input terminal.

The AV switch circuit 6 detects whether or not a connection cord is connected to the BS input terminal 8 and uses the switch control signal g1 from the BS reception circuit 3 and the second switch control signal t1 from the connection point A1. Based on the selection of input terminals.

More specifically, the AV switch circuit 6 detects that the connection code is not connected to the BS input terminal 8 and that the switch control signal g1 from the BS reception circuit 3 is not scrambled. In the case where the second switch control signal t1 from the connection point A1 is at a low level, the video signal d1 and the audio signal e1 from the BS receiving circuit 3 are used as the video signal p1 and the audio signal q1 and the video display circuit 10 and the audio output. Supply to the circuit 11. Also,
When the AV switch circuit 6 detects that the connection cord is not connected to the BS input terminal 8 and the switch control signal g1 from the BS receiving circuit 3 indicates that scrambling is performed, the BS input terminal No signal from 8 is supplied to the video display circuit 10 and the audio output circuit 11. Further, the AV switch circuit 6 detects that the connection cord is connected to the BS input terminal 8, and when the second switch control signal t1 from the connection point A1 is at the low level, the BS
The video signal k1 and the audio signal m1 from the input terminal 8 are supplied to the video display circuit 10 and the audio output circuit 11 as the video signal p1 and the audio signal q1. Further, the AV switch circuit 6 receives the second switch control signal t1 from the connection point A1.
Is high level, the luminance signal input terminal 9 of the S terminal 9
The luminance signal n1Y and the color signal n1C from the Y and color signal input terminals 9C are supplied to the video display circuit 10 as the luminance signal p1Y and the color signal p1C from different wirings, respectively.
The audio signal m1 from the BS input terminal 18 is supplied to the audio output circuit 11 as the audio signal q1.

When the video signal p1 is supplied, the video display circuit 10 creates a luminance signal and a color signal from the video signal p1 and creates three primary color signals from the created luminance signal and the color signal. The image is displayed on the CRT. In addition, when the luminance signal p1Y and the color signal p1C are supplied, the video display circuit 10 uses the luminance signal p1Y and the color signal p1C to determine 3
Create a primary color signal and display it on a cathode ray tube. The audio output circuit 11 causes the audio output means such as a speaker to output the supplied audio signal q1 as audio.

The operation of such an embodiment will be described below.

When the connection code is not connected to the BS input terminal 8 and the normal BS broadcast is received without connecting the connection, the first switch control signal g1 indicates that scrambling is not performed, and MUSE-NTSC is used. The luminance signal n1Y and the color signal n1C from the converter 31 become no signals, and the outputs from the luminance signal detection circuit 12 and the squeeze detection circuit 13 are
Both become low level, and the second of the AV switch circuit 6
The second switch control signal t1 that is guided to the switch control signal input terminal of 1 becomes low level, and the AV switch circuit 6 selects the first video and audio signal input terminal. Accordingly, the composite video signal d1 and the audio signal e1 of the NTSC system are supplied from the receiving circuit 3 to the video display circuit 10 and the audio output circuit 11 via the AV switch circuit 6, and the video display and the audio output are performed.

When a connection code is connected to the BS input terminal 8 to receive a normal BS broadcast and a scrambled broadcast, the luminance signal n1Y and the color signal n1C from the MUSE-NTSC converter 31 become no signals, and the luminance signal is detected. The outputs from the circuit 12 and the squeeze detection circuit 13 both become low level, the AV switch circuit 6 selects the second video and audio signal input terminal, and the video signal i1 and the audio signal j1 from the scramble broadcast decoder are received. It is supplied to the video display circuit 10 and the audio output circuit 11 via the AV switch circuit 6, and the video is displayed and the audio is output.

When receiving the MUSE satellite broadcast signal and displaying the image in the squeeze mode, MUSE-N is used.
The luminance signal n1Y and the color signal n from the TSC converter 31
1C becomes a signal, and the squeeze signal is superimposed on the color signal n1C, the outputs of the luminance signal detection circuit 12 and the squeeze detection circuit 13 both become high level, and the AV switch circuit 6 has a luminance signal input terminal. And the color signal input terminal and the second BS input terminal are selected. On the other hand, the vertical amplitude switching circuit 15 compresses the amplitude of the vertical deflection signal to 3/4, and performs horizontal and vertical deflection for performing scanning with a 16: 9 aspect ratio on a cathode ray tube with an aspect ratio of 4: 3. Supply a signal. As a result, MUSE-NTS
Luminance signal n1Y and color signal n1C from C converter 31
Is supplied to the video display circuit 10 via the AV switch circuit 6 and is displayed as a video having 525 scanning line displays in the central 3/4 area in the vertical direction of the cathode ray tube having an aspect ratio of 4: 3. It MUSE-NTSC
The audio signal m1 from the converter 31 is supplied to the audio output circuit 11 via the AV switch circuit 6 and is output as audio.

When receiving a MUSE satellite broadcast signal and displaying an image in the letterbox mode, MUSE-
The luminance signal n1Y and the color signal n1C from the NTSC converter 31 become a signal, but the squeeze determination signal is not superimposed on the color signal n1C, the output of the luminance signal detection circuit 12 becomes high level, and the output of the squeeze detection circuit 13 becomes , The AV switch circuit 6 selects the luminance signal input terminal, the color signal input terminal, and the second BS input terminal. On the other hand, the vertical amplitude switching circuit 15 does not compress the amplitude of the vertical deflection signal, but outputs the horizontal and vertical deflection signals for performing the scanning of the aspect ratio of 4: 3 to the cathode ray tube having the aspect ratio of 4: 3. Supply. As a result, MUS
The luminance signal n1Y and the color signal n1C from the E-NTSC converter 31 are supplied to the video display circuit 10 via the AV switch circuit 6, and are displayed on the screen of a 4: 3 cathode ray tube 525.
An image having a normal aspect ratio is displayed on the central 3/4 portion of the screen with the lower 1/8 of the upper 1/8 of the scanning lines of the book as a margin portion. MUSE-NTSC converter 31
The audio signal m1 from is supplied to the audio output circuit 11 via the AV switch circuit 6 and is output as audio.

FIG. 2 is a circuit diagram showing the luminance signal detection circuit, the squeeze detection circuit of FIG. 1 and peripheral circuits of these circuits.

In FIG. 2, reference numeral 101 is an input terminal to which a constant DC voltage Vcc is introduced.
Is connected to the power supply line of the luminance signal detection circuit 12, the power supply line of the squeeze detection circuit 13, and the power supply line of the squeeze detection circuit 13.

The luminance signal input terminal 9Y of the S terminal 9 is connected to the input terminal of the luminance signal detection circuit 12 and at the same time A
It is connected to the luminance signal input terminal of the V switch circuit 6. S
The color signal input terminal 9C of the terminal 9 is the squeeze detection circuit 1
3 is connected to the input terminal of the capacitor C31
Is connected to the color signal input terminal of the AV switch circuit 6 via. The connection point between the capacitor C31 and the color signal input terminal of the AV switch circuit 6 is connected to the reference potential point via the resistor R31. With such a connection, the capacitor C31 and the resistor R31 form a direct current removal circuit, and prevent the squeeze determination signal from being guided to the AV switch circuit 6.

First, the luminance signal detection circuit 12 will be described.

The power supply line of the luminance signal detection circuit 12Y is connected to the reference potential point through the series connection of the resistors R11 and R12, and also through the series connection of the collector / emitter path of the NPN transistor Tr11 and the resistor R13. The PNP transistor Tr is connected to the reference potential point.
12 are connected to the reference potential point through a series connection of the emitter / collector path and the resistor R14, and the resistor R15
Is connected to a reference potential point through a series connection of the PNP transistor T13 and the NPN transistor Tr13.
It is connected to the reference potential point through the series connection of the emitter-collector path of r14 and the resistor R16.

The luminance signal input terminal 9Y of the S terminal 9 is connected to the reference potential point via the resistor R17 of the luminance signal detection circuit 12, and is also connected to the resistor R1 via the capacitor C11.
It is connected to the connection point of 1 and R12. Resistors R11, R12
Is connected to the base of the NPN transistor Tr11. The emitter of the NPN transistor Tr11 is
PNP transistor Tr12 via capacitor C12
Connected to the base of. The base of the PNP transistor Tr12 is connected to the reference potential point via the resistor R18. The collector of the PNP transistor Tr12 is connected to the base of the NPN transistor Tr13 via the capacitor C13. The collector of the NPN transistor Tr13 is connected to the power supply line via the capacitor C14 and is also connected to the base of the PNP transistor Tr14. The collector of the PNP transistor Tr14 is connected to the anode of the transistor D1. With such a connection, the resistors R11, R12, R13, R17, the capacitor C11 and the NPN transistor Tr11 form the buffer amplifier 201, and the resistors R14, R18, the capacitor C12 and the PNP transistor Tr12 form the first synchronous tip amplifier 202. Resistor R15 and capacitor C1
3 and the NPN transistor Tr13 form a second synchronous tip amplifier 203, and the resistor R16, the capacitor C14 and the PNP transistor Tr14 form the synchronous tip determination circuit 20.
Make up 4.

The luminance signal n1Y supplied to such a luminance signal detection circuit 12 has resistors R11, R12, R13,
R17, capacitor C11 and NPN transistor Tr
The resistor R1 is connected via the buffer amplifier 201 composed of 11
4, a first synchronous tip amplifier 202 composed of R18, a capacitor C12 and a PNP transistor Tr12, a resistor R15, a capacitor C13 and an NPN transistor Tr.
The synchronous component is amplified by the second synchronous tip amplifier 203 composed of 13, and the resistor R16, capacitor C14 and P
Synchronous leading edge determination circuit 2 including NP transistor Tr14
The sync tip is determined by 04. When the luminance signal n1Y is a signal, the PNP transistor Tr14 is turned on and the high level detection signal r1 is supplied to the diode D1. When the luminance signal n1Y is no signal, the PNP
The transistor Tr14 is turned off, and the low level detection signal r1 is supplied to the diode D1.

Next, the squeeze detection circuit 13 will be described.

The power supply line of the squeeze detection circuit 13 is connected to the reference potential point through the series connection of the resistor R21 and the collector-emitter path of the NPN transistor Tr21, and the resistor R22 and the collector-emitter path of the NPN transistor Tr22 are connected. It is connected to the reference potential point via a series connection with.

The color signal input terminal 9C of the S terminal 9 is connected to the base of the NPN transistor Tr21 via the resistor R23 of the squeeze detection circuit 13. The base of the NPN transistor Tr21 is connected to the reference potential point via the capacitor C21 and is also connected to the reference potential point via the resistor R24.

The collector of the NPN transistor Tr21 is connected to the base of the NPN transistor Tr22. The collector of the NPN transistor Tr21 is connected to the anode of the diode D2 and the input terminal of the vertical amplitude switching circuit 15.

A color signal component of the color signal n1C supplied to the squeeze detection circuit 13 is removed by the capacitor C21, and a DC component is supplied to the NPN transistor Tr21.

When the squeeze discrimination signal is superimposed on the color signal n1C, the NPN transistor Tr21 is turned on, the NPN transistor Tr22 is turned off, the high-level detection signal s1 is supplied to the vertical amplitude switching circuit 15, and the diode is also supplied. It is supplied to the anode of D2.

When the squeeze discrimination signal is not superimposed on the color signal n1C, the NPN transistor Tr21 is turned off, the NPN transistor Tr22 is turned on, and the low level detection signal s1 is supplied to the vertical amplitude switching circuit 15. It is supplied to the anode of the diode D2.

The second switch control signal t1 output from the connection point A1 of the anodes of the diodes D1 and D2 becomes low level when both the detection signals r1 and s1 are low level, and at least the detection signals r1 and s1. If one is high level, it becomes high level.

In the circuit shown in FIG. 2, MUSE-N
Table 1 shows the relationship between the mode of the TSC converter 31, the DC component of the color signal input terminal 9C of the contact 9, the second switch control signal t1 at the connection point A1, and the detection signal s1 of the squeeze detection circuit 13.

[0067]

[Table 1] Here, H indicates a high level, L indicates a low level, and the no-signal mode indicates a mode in which the MUSE-NTSC converter 31 guides no signal to the luminance signal input terminal 9Y and the color signal input terminal 9C of the S terminal 9. There is.

According to such an embodiment, when the MUSE satellite broadcast signal is received, the AV switch circuit 6 automatically displays the luminance signal n1Y and the color signal n1C from the MUSE-NTSC converter 31. Since it is supplied to the display circuit 10, it is possible to simplify the operation when receiving the MUSE satellite broadcast signal in the state where the color signal and the luminance signal do not interfere so much. Further, according to such an embodiment, the squeeze detection circuit 13 detects the presence or absence of the squeeze discrimination signal superimposed on the color signal n1C, and the direct amplitude switching circuit 15 responds to the detection result of this squeeze discrimination signal. Since the screen scanning is switched, an image with a normal aspect ratio can always be obtained.

In the embodiment of FIG. 1, two FM detection output terminals of the television receiver 1 are provided. However, by combining the FM detection output terminals into one and branching the connection cord, a scrambled broadcast decoder is provided. 41 and MUSE-NTS
It may be connected to the C converter 31.

[0070]

According to the present invention, when the MUSE satellite broadcast signal is received, the luminance signal and the color signal from the luminance signal input terminal and the color signal input terminal connected to the MUSE-NTSC converter are automatically detected. Since it is possible to switch and select to display the image, it is possible to simplify the operation when receiving the MUSE satellite broadcast signal in the state where the color signal and the luminance signal do not interfere much.

[Brief description of drawings]

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

FIG. 2 is a circuit diagram showing a luminance signal detection circuit, a squeeze detection circuit, and peripheral circuits of these circuits shown in FIG.

FIG. 3 is a block diagram showing a conventional television receiver.

[Explanation of symbols]

 1 Television Receiver 4,14 FM Detection Output Terminal 3 BS Reception Circuit 6 AV Switch Circuit 8 BS Input Terminal Circuit 9 S Terminal 9C Color Signal Input Terminal 9Y Luminance Signal Input Terminal 10 Video Display Circuit 21 Parabolic Antenna 22 First Converter 31 MUSE-NTSC Converter 41 Scrambled Broadcast Decoder

Claims (1)

[Claims] 1. FM by receiving a satellite broadcast signal
A satellite broadcast receiving circuit that outputs a detection signal and a bit stream signal, an FM detection signal from this satellite broadcast receiving circuit is guided, and is connected to the FM detection input terminal of the scrambled broadcast decoder and the MUSE-NTSC converter via a connection cord. An FM detection output terminal, a bit stream output terminal to which a bit stream signal from the satellite broadcast receiving circuit is guided and which is connected to a bit stream input terminal of the scramble broadcast decoder via a connection cord, and a scramble broadcast decoder. A satellite broadcast input terminal connected to the video signal output terminal via a connection cord, a luminance signal input terminal connected to the luminance signal output terminal of the MUSE-NTSC converter via a connection cord, and a MUSE-NTSC converter Via the connection cord to the color signal output terminal A color signal input terminal to be connected and a luminance signal and a color signal are created from the video signal from the satellite broadcast input terminal, and a signal for display is created from the created luminance signal and the color signal to display an image, A video display circuit that creates a display signal from a brightness signal from the brightness signal input terminal and a color signal from the color signal input terminal to display a video, and detects the presence or absence of a brightness signal from the brightness signal input terminal. A luminance signal detection circuit for providing a video signal from the satellite broadcast input terminal, a luminance signal from the luminance signal input terminal, and a color signal from the color signal input terminal to the video display circuit, If there is no detection result of the signal detection circuit, the video signal from the satellite broadcast input terminal is guided to the video display circuit, and if there is a detection result of the brightness signal detection circuit, the brightness signal input A television receiver comprising a switch circuit for guiding a luminance signal from a terminal and a color signal from the color signal input terminal to the video display circuit.