JPH03166876A - Television receiver - Google Patents

Abstract

PURPOSE:To display a broadcast system in characters when a signal unabte to decode is received by providing a discrimination means discriminating the reception of a television signal of the broadcast system not decoded and a display means for character information. CONSTITUTION:When a program by the MUSE system is received, a moving contact of a switch circuit 3 is thrown to the fixed contact of a video detection circuit 2. In this case, since a MUSE discrimination signal MS fed from a MUSE discrimination circuit 4 goes to '1' a synchronizing signal generating circuit 10 generates a vertical synchronizing signal VD and a horizontal synchronizing signal HD for the NTSC system and moving contacts of switch circuits 9,11 are thrown to the position of fixed contact of the generator 10 respectively by a channel selection CPU 21. The CPU 21 converts into R, G, B signals corresponding to a character string as 'During reception of MUSE broadcast program' from a character ROM 23 and gives the signal to an input port of a superimposition circuit 15 and applies a green signal G to a superimposing signal input terminal of a superimposing circuit 19, then the character of 'During reception of MUSE broadcast program' is displayed on a display screen (not shown).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a television receiver capable of decoding only, for example, a normal NTSC television signal.

[Summary of the invention]

The present invention provides a television receiver capable of decoding only a television signal of a predetermined broadcasting method, and a determining means for determining that a television signal of a broadcasting method other than the predetermined broadcasting method that cannot be decoded is received. and character information display means, and when a television signal of a broadcasting system that cannot be decoded is received, this broadcasting system is displayed as a character, thereby indicating that a television signal of the broadcasting system that cannot be decoded has been received. It is made so that viewers can recognize it.

[Conventional technology]

Satellite broadcasting using geostationary satellites has been put into practical use.

Regarding this satellite broadcasting, Japan has the 12GHz band,
Channel (BS-1) to 15th channel (BS-
A total of 8 channels (odd channels up to 15) are allocated, and the bandwidth per channel is 27.
! J }I z.

Currently, the satellite broadcasting programs include standard television broadcasting programs with 525 horizontal scanning lines per frame, as well as programs with 125 horizontal scanning lines per frame.
Five high-definition television broadcasting (so-called high-definition) programs are also being experimentally broadcast. In this case, the bandwidth of the baseband signal of the high-definition television broadcasting system is about 20M}lz, but this cannot be transmitted on one channel of satellite broadcasting, so MUSIE (Multi
ple Sub-nyquistSampling E
ncoding) method, that 20MHz becomes 8MHz.
z and is transmitted with band compression.

In addition, since the NTSC 7 system is adopted in Japan as the color standard television broadcasting system, the NTSC
The SC system will be cited as an example of the standard television broadcasting system.

[Problem to be solved by the invention]

As mentioned above, in satellite broadcasting, even if they are on the same channel, there are programs in the NTSC system, which is the standard television broadcasting system, and MU, which is the high-definition television broadcasting system.
It is broadcast in a mixed format with SE format programs.

However, since decoders for the MUSB system are large and expensive, ordinary home television receivers capable of receiving satellite broadcasting are often equipped with only one decoder for the NTSC system.

If a television receiver equipped with only a decoder for the NTSC system receives a MIJ S E system program, the synchronization will be disrupted and a normal image will not be displayed. There was an inconvenience in that it could be mistakenly assumed that the machine was malfunctioning, which could lead to complaints.

On the other hand, in the future, the number of high-definition television broadcasting programs will increase, and television receivers will be equipped with only decoders for the high-definition television broadcasting system, and NTSC programs will be received. A similar problem occurs when a normal image is not displayed.

In view of this, it is an object of the present invention to take measures when a television receiver capable of decoding only a television signal of a predetermined broadcasting method receives a television signal that cannot be decoded of a method other than the predetermined broadcasting method. do.

[Means to solve the problem]

The television receiver according to the present invention, as shown in FIG. 1, for example, is a television receiver that can only decode television signals of a predetermined broadcasting system (NTSC system), and cannot decode television signals other than that of the predetermined broadcasting system. A determining means (4) for determining that a television signal of the broadcasting system (MtISE system) has been received, and a character information displaying means (15). (21). (23), and when a television signal of a broadcast system that cannot be decoded is received, this broadcast system is displayed in characters (for example, "Receiving MtlSE broadcast").

Further, in the present invention, the broadcast system is a standard television broadcast system, and the broadcast system that cannot be decoded is a high-definition television broadcast system.

Further, in the present invention, the broadcasting system is a high-definition television broadcasting system, and the broadcasting system that cannot be decoded is a standard television broadcasting system.

[Effect]

According to the present invention, when a television signal of a broadcasting system that cannot be decoded is received, this broadcasting system is displayed as a character, so that the viewer can easily see that the program currently being received is a program of a broadcasting system that cannot be decoded. can be recognized with certainty.

〔Example〕

below. An embodiment of a television receiver according to the present invention will be described with reference to FIGS. 1 and 2. In this example, N
The present invention is applied to a television receiver that can decode only TSC television signals.

Fig. 1 shows the television receiver of this example. In Fig. 1, (1) is an SHF tuner for the SHF band, which is the band of satellite broadcasting, and (2) is a video detection circuit. The signal obtained by FM demodulation in the circuit (2) is supplied to one fixed contact of the switch circuit (3) and the input terminal of the MIISE discrimination circuit (4). The SHF tuner (
If the program on the channel selected in 1) is an NTSC program, the NTSC video signal (NT
SC signal) is supplied to the switch circuit (3) and the MLISIE discrimination circuit (4), and when the program is a MUSE system program, the MtISE system television signal (
MtlSB signal> is connected to the switch circuit (3) and MtlSB
The signal is supplied to the discrimination circuit (4).

This MUSE! The discrimination circuit (4) determines whether the supplied signal is M
[MIJSB becomes high level “1” when the signal is an ISE signal and becomes low level “0” when the supplied signal is other than the MIISB signal (for example, an NTSC signal)
Observe the discrimination signal MS. M VIT (Ver.
A frame pulse as a frame synchronization pattern signal is included as well as a frame synchronization pattern signal. The frame pulse of the first line (29
) is as shown in FIG. 2A < 16. If one period of a 2 MHz clock pulse is ICK, it is composed of 17.5 periods of pulses that are inverted at intervals of 4 CKs (ie, 1 period is 8 CKs). Further, the frame pulse (30) of the second line is constructed by inverting the frame pulse (29) of the first line, as shown in FIG. 2B. Therefore, the MIIS8 discriminating circuit (4) of this example uses a predetermined distinction between the first line horizontal scanning signal whose period is 8CK and the second line whose horizontal scanning signal is inverted and whose period is 8CK. The correlation between the periods is detected, and the supplied signal is determined to be the M 11 SE signal only when the correlation is high.

(5) is a U/V china for UHF band and VHF band, (
6) shows a video detection circuit, and the NTSC signal obtained by AM demodulation in this video detection circuit (6) is sent to a switch circuit (
3) to the other fixed contact of this switch circuit (3).
) is supplied to the Y/C separation circuit (7) as an NTSC signal decoder, one fixed contact of the switch circuit (9), and the synchronization signal detection circuit (8),
The MUSE discrimination signal MS is supplied to a synchronization signal generator (lO) and a tuning microcomputer (21) to be described later.

When the demodulated signal is an NTSC signal, the synchronization signal detection circuit (8) separates the vertical synchronization signal VD and horizontal synchronization signal HD from the NTSC signal and sends the signal to the switch circuit (1).
1) to one fixed contact of the synchronous signal generator (10
> is when the MUSB discrimination signal MS is high level “1” (when the demodulated signal is the MUSE signal),
Vertical synchronization signal VD and horizontal synchronization signal H for NTSC signal
D is generated and supplied to the other fixed contact of the switch circuit (9) and the other fixed contact of the switch circuit (1l).

The three primary color signals R generated by the Y/C separation circuit (7)
. l5). In addition, the composite video signal appearing at the movable contact of the switch circuit (9) is processed by a half-planking circuit (16) for NTSC video signals, and a superimposition processing circuit (1).
7), planking circuit (18) and superposition circuit (19)
The video signal is converted into a composite video signal with character information added thereto and supplied to an output terminal (20).

(21) is a channel selection microcomputer (hereinafter referred to as "channel selection CPUJ") that controls the operation of the television receiver of this example, and (22) is a channel selection microcomputer that controls the operation of the television receiver of this example.
An oscillator that supplies to P U (21), (23) indicates a character ROM, and this channel selection C is used during normal screen display.
P U (21) performs half planking times using half planking signal Ym! (12) and (16), and the image data of a predetermined character read from the character ROM (23) is controlled by the three primary color signals R, G,
B and supplies it to the other input port of the superimposition circuit (15). In this case, the three primary color signals R, G, B output from the channel selection CPU (21) are supplied to the addition circuit (24),
This adder circuit (24) goes to a high level when the result of adding these three primary color signals R, G, and B exceeds a predetermined level.
1” and the low level is “0” when it is tarred below a predetermined level.
”, and the superimposition processing circuits (l3) and (17) are controlled by this superimposition signal Ys. In addition, the three primary color signals R, output from the channel selection CPU (21) are Green signal G of G and B is superimposed circuit (l9)
is superimposed on the composite video signal as a white level.

In addition, NT appearing at the movable contact of the switch circuit (11)
SC system vertical synchronization signal VD and horizontal synchronization signal HD for channel selection CPU (21) and synchronization signal output terminal (28)
The three primary color signals R, G, and B are supplied to a deflection processing circuit (not shown) through the superimposing circuit (15) and are outputted through the video signal output terminals (25), (26), and (27). It is supplied to a cathode ray tube (not shown). And CP for channel selection
U (21) C, MUS[MUSE discrimination signal MS supplied from the E discrimination circuit (4) is at high level "1"
” (when the demodulated signal is the 1,III SE signal), the movable contacts of the switch circuits (9) and (11) are respectively switched to the synchronizing signal generator (IO) side, and the M[ When the ISE discrimination signal MS is low level "0" (when the demodulated signal is an NTSC signal), the movable contacts of the switch circuits (9) and (11) are connected to the switch circuits (9) and (11), respectively.
3) to the movable contact side and the synchronous signal detection circuit (8) side.

To explain the operation when the television receiver of this example receives a program by the MUSE method of satellite broadcasting, in this case, the movable contact of the switch circuit (3) is connected to the video detection circuit (2).
) side is connected to the fixed contact. In this case, Must
! M [ISE discrimination signal M supplied from the discrimination circuit (4)
Since S becomes high level “1”, the synchronization signal generator (1
0>, a vertical synchronization signal VD and a horizontal synchronization signal HD for the NTSC system are generated, and the channel selection CPU (21
), the movable contacts of the switch circuits (9) and (l1> are respectively switched to the fixed contacts of the synchronizing signal generator (lO>).Furthermore, the channel selection CPU (21) uses the planking signal BLK to Planking times lid (14) and (
18>, the three primary color signals supplied to one input port of the superimposing circuit <15) and the superimposing circuit (1
9> are both converted into signals corresponding to the black level.

The channel selection CPU (21) is a character ROM.
(23), the data corresponding to the character string "MIJSEi broadcasting being received" is read out, and the three primary color signals R, G are read out. The display screen of the cathode ray tube (not shown in the figure) is “+JUS” with black level as background.
8 “Receiving broadcast” will be displayed, and the output terminal (20) will be displayed.
From there, a composite video signal VS corresponding to the character example is supplied to, for example, a video tape recorder (not shown).

According to this example as mentioned above,! When a program in the JUSE format is received, a character string indicating that the program in the MISE format is being received is displayed on the display screen, so that the viewer does not know that the program in the MUSE format is being received. It is possible to reliably identify that Therefore, there is an advantage that the viewer will not mistakenly believe that the television receiver is broken, and the number of complaints will be reduced.

On the other hand, when an NTSC program is received, the channel selection CPU (21) switches between the switch circuit (9) and (l
By switching the movable contacts of 1) to the movable contact side of the switch circuit (3) and the synchronous signal detection circuit (8) side, respectively,
The NTSC program is displayed on a display screen (not shown).

Next, another embodiment of the present invention will be described with reference to FIGS. 3 and 4. This example is MUSE! in satellite broadcasting.
The present invention is applied to a television receiver capable of decoding only a television signal of the same system. In FIG. 3, parts corresponding to those in FIG. 1 are given the same reference numerals, and detailed explanation thereof will be omitted.

FIG. 3 shows the main parts of the television receiver of this example. In FIG. 3, when the program on the channel selected by the SHF tuner (1) is an M 11 S E system program, From the video detection circuit (2)
A signal is supplied to the MUSE decoder (31), and this Mt
The lSE decoder (31) generates a vertical synchronization signal VDH and a horizontal synchronization signal HDH for high-definition television broadcasting and supplies them to one fixed contact of the switch circuit (34), and this MusB decoder (31) That M [IS
The B signal is decoded to generate baseband three primary color signals R, G, and B of the high-definition television broadcast system, and these three primary color signals R, G, and B are supplied to a half-planking circuit (12).

In addition, the signal obtained by FM demodulation in the video detection circuit (2) is constantly supplied to the NTSC discrimination circuit (32), and this NTSC discrimination circuit (32) determines whether the supplied signal is NTSC.
It generates an NTSC discrimination signal NS which has a high level "1" when the supplied signal is a MUSE signal and a low level "0" when the supplied signal is a MUSE signal, and this NTSC discrimination signal MS is used as a channel selection CPU. (21) and synchronization signal generator (
33). To explain the operating principle of this NTSC discrimination circuit (32), the NTSC signal generally consists of a horizontal synchronizing signal (35) with a time r0 (4 to 5 μsec) and an asynchronous signal with a time τl (35 to 60 μsec), as shown in FIG. The department is more organized. Therefore, the NTSC discrimination circuit (32) of this example determines whether the supplied signal is an NTSC signal depending on whether the time τ0 of the synchronous signal (35) and the time τ1 of the asynchronous signal part fall within a predetermined standard range. It is determined whether

When the NTSC discrimination signal NS is at a high level "1", the synchronization signal generator (33) generates the vertical synchronization signal VDH and horizontal synchronization signal HD for the high-definition television broadcasting system.
H is generated and supplied to the other fixed contact of the switch circuit (34), and the channel selection CPU (21) connects the movable contact of the switch circuit (34) to the fixed contact of the synchronous signal generator (33). Connect to the contacts. The synchronizing signals HDH and VDH appearing on the movable contacts of the switch circuit (34) are transmitted to the channel selection CPU (2).
1) and the synchronization signal HDH, VD supplied to the synchronization signal output terminal (28) and supplied to the channel selection CPU (21).
H is used for positioning when character information is displayed on the display screen.

Furthermore, the NTSC discrimination signal NS is at high level #111.
(when the demodulated signal is an NTSC signal), the channel selection CPU (21) is a character ROM.
(23) reads the data corresponding to the character string “MTSC broadcasting being received” and converts it into three primary color signals R, G, B,
While supplying these three primary color signals to the input port of the addition circuit (24) and the other input port of the superimposition circuit (15),
Planking circuit using planking signal BLK
4), the three primary color signals supplied from the MUSE decoder (31) side are set to the black level. Therefore, on the display screen of the cathode ray tube (not shown), the text string "Receiving MTSC broadcasting" is displayed against a black-level image in the background, so the viewer can be sure that the NTSC program is being received. There are discernible benefits.

On the other hand, when the NTSC discrimination signal NS is at low level "0" (when the demodulated signal is a MUSB signal)
The CPU (21) for channel selection is connected to the switch circuit (3).
In order to switch the movable contact in 4) to the fixed contact on the MUSE decoder (31) side and turn off the planking signal BLK, a high-definition television broadcast program is displayed on the display screen (not shown). .

In the above-mentioned embodiment, the broadcast system that cannot be decoded is displayed on the screen as character information, but the present invention is not limited to this, and for example, a panel of light emitting diodes (LEDs) may be placed around the display screen. Install this LE
The panel D may display that a program of a broadcasting system that cannot be decoded is being received.

In this way, the present invention is not limited to the above-mentioned embodiments, and for example, N
Of course, various configurations can be adopted without departing from the gist of the present invention, such as application to a cable television receiver that uses both the TSC system and the MUS B system.

〔Effect of the invention〕

According to the present invention, when a television signal of a broadcasting system that cannot be decoded is received, this broadcasting system is displayed as a character, so that the viewer can be sure that the television signal of the broadcasting system that cannot be decoded has been received. Are there any discernible benefits?

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a main part of an embodiment of a television receiver according to the invention, FIG. 2 is a signal waveform diagram showing a MUSE signal, and FIG. 3 is a main part of another embodiment of the invention. FIG. 4 is a signal waveform diagram showing the MUSE signal. (2) is a video detection circuit, (4) is an MυSE' discrimination circuit,
(15) is a superimposition circuit, (2l) is a channel selection microcomputer (channel selection CPU), (23) is a character ROM, and (32) is an NTSC discrimination circuit. Agent Hidemori Matsukuma Figure 2 1 7b NTSC A word Figure 4

Claims (1)

[Claims] 1. A television receiver capable of decoding only television signals of a predetermined broadcasting method, which determines that a television signal of a broadcasting method other than the predetermined broadcasting method that cannot be decoded is received. What is claimed is: 1. A television receiver comprising: discriminating means for decoding, and character information display means, and when a television signal of a broadcasting system that cannot be decoded is received, the television receiver displays characters of the broadcasting system. 2. The television receiver according to claim 1, wherein said predetermined broadcasting system is a standard television broadcasting system, and said broadcasting system that cannot be decoded is a high-definition television broadcasting system. 3. The television receiver according to claim 1, wherein the predetermined broadcasting system is a high-definition television broadcasting system, and the broadcasting system that cannot be decoded is a standard television broadcasting system.