JPS63167591A - Superimposing device - Google Patents

Abstract

PURPOSE:To superimpose a teletext signal having a standard horizontal scanning frequency onto an internal video signal of the non-interlace system by providing a double speed converting means converting the horizontal scanning frequency of the teletext signal. CONSTITUTION:The interlace system television video signal having the standard horizontal scanning frequency is converted into the non-interlace system video signal having a horizontal scanning frequency of 31.5kHz by a processing section 14. On the other hand, teletext picture signals RO, GO, BO having the standard horizontal frequency given from a teletext receiver and a primary color video signal switch control signal YS and a luminance control signal YM are converted into signals DRO', DGO', DBO', YM', YS' having the horizontal scanning frequency of 31.5kHz by double speed converters 56-70. With the switching signal YS' and the luminance control signal YM' at logical 1, a 1/2 attenuator 16 applies attenuation processing to the internal video signals DRi'-DBi' and the switch 18 is switched to the teletext to apply superimposition.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a superimposing device for a television receiver, and in particular, superimposing an external primary color video signal onto an internal primary color video signal converted from an interlaced system to a non-interlaced system. This allows for imposition.

(Prior Art) Teletext broadcasting, which has recently attracted attention as a new media, transmits text signals containing information such as characters and graphics along with regular television video signals. If you prepare a device, you can select your desired teletext program from among many teletext programs.

Currently, there are three types of teletext receivers: the first type is a television receiver with a built-in character decoder;
The second type is a connection type adapter that is compatible with television receivers equipped with a 21-pin multi-connector, and the third type is an independent type adapter that can also be connected to conventional television receivers.

FIG. 9 shows the main components of a conventional television receiver connected to a second type teletext receiver.

An NTSC television signal SNTSC detected by a tuner (not shown) is input to the input terminal 300. This television signal S NTSC is NTSC
The signal is supplied to the decoder 302 and also sent to the teletext receiver 400 via the video signal output terminal 322 of the 21-pin multi-connector 320.

The NTSC decoder 302 receives the television signal S NT
After separating the SC into a luminance signal Y and a color signal C and subjecting them to predetermined signal processing, they are passed through an RGB mask circuit to produce primary color video signals R1 and Gi.

Generate Bl. These primary color video signals RI, GI.

Bl passes through a 1/2 attenuator 304 and is applied to input terminals 308A, 310A, and 312A of a switching circuit 306, respectively.

On the other hand, the teletext receiving device 400 receives the television signal S
The character data superimposed during the NTSC vertical blanking period is extracted, code errors are detected and corrected, and then decoded to produce the primary color video signals Ro, Go, and B that constitute the teletext screen.
generate o. These primary color video signals Ro, Go
+BO is the red input terminal 324 and green input terminal 32 of the 21-pin multi-connector 320 as external primary color video signals.
6. input terminals 308B, 310B of switching circuit 306 via blue input terminal 328;

312B, respectively.

The teletext receiving apparatus 400 also transmits the primary color video signal switching control signal YS and the brightness control signal YM to the YS input terminal 332. It is applied to the YM input terminal 330. These signals Y
S and YM are respectively switching circuits 308.1/2M attenuator 3
04 control terminal. The primary color video signal switching control signal YS becomes "1" when displaying text/graphic images of teletext on the cathode ray tube, and in response, the switching circuit 30
6 switches 308, 310, and 312 are configured to switch to input terminals 308B, 310B, and 312B, respectively. The brightness control signal YM includes internal primary color video signals R1, Gl, and Bl of television broadcast images and external primary color video signals Ro, Go, and B of teletext images.

becomes “1” when superimposing, and reacts to it! /2 attenuator 304 receives internal primary color video signals R1,G.
It works to reduce the brightness of B1 by half. The 21-pin multi-connector 320 also has 16 terminals 334 to 364.
For example, terminal 334 is an audio input terminal, terminal 364 is
is the ground terminal.

In addition, in FIG. 9, the output terminals 314, 316, 31
Internal primary color video signals R1, G [,
B i or external primary color video signals Ro, Go.

Bo is sent to the cathode ray tube through a video output amplifier (not shown) in the next stage.

Next, referring to FIG. 10, the internal primary color video signal R1°G i,
The effect when external primary color video signals Ro, Go, and Bo are superimposed on B i will be explained.

A television video signal (R+, G
1. B When character screen signals (Ro, Go, Bo) as shown in FIG. 10(B) are superimposed on B1), as shown in FIG. 10(C) and (D), respectively. A primary color video signal switching control signal YS and a brightness control signal YM are provided from the teletext receiver 400. As mentioned above, when the switching control signal YS is "1", the changeover switch 306 is connected to the external primary color video signal input terminal 308B.
, 310B, 312B, and the character screen signal (R
o, Go, Bo) are sent to the cathode ray tube, and the teletext image is displayed on the screen. When the switching control signal YS is “0”, the changeover switch 306 is connected to the internal primary color video signal terminal 308.
B.

310B and 312B, and the TV video signal (R
1, Gl, Bl) are sent to a cathode ray tube, and the television broadcast image is displayed on the screen. However, the brightness control signal YM is “
1'', the 1/2 attenuator 304 operates to halve the amplitude of the television video signal (R1, G1, B1), thereby halving the brightness of the television broadcast image and emphasizing the character image. It will look like this.

(Problems to be Solved by the Invention) Incidentally, in parallel with the development of new media, various attempts have been made to dramatically improve the image quality of television images, and one method is IDTV (Improved TV).
Definltlon TV). This improves the definition of images on TV receivers without changing the current broadcasting system (for example, NTSC system).
Specifically, the standard horizontal scanning frequency (15,75kHz) is doubled (31,5kHz) by interpolating the horizontal scanning lines.
) and display 525 horizontal scanning lines on the screen every I/Hsec, thereby eliminating interline flicker seen in normal interlaced scanning and improving vertical resolution.

Now, when such IDTV is applied to a television receiver, for example, in the receiver shown in FIG.
Internal primary color video signal R1, G given to the input terminal of 04
The horizontal scanning frequency of L and Bl is now 15.75kHz.
It will change from z to 31.5kHz which is double that.

However, the external primary color video signals Ro, Go, and Bo sent from the teletext receiving device 400 are still 15.
Since it has a horizontal scanning frequency of 75 kHz, a problem arises in that the two primary color video signals cannot be synchronized and superimposition becomes impossible.

Such problems arise when the external primary color video signal Ro + Go
This problem may occur even if the +Bo signal source is a Videotex, personal computer, or the like.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a superimposing device that can superimpose an external primary color video signal onto an internal primary color video signal converted from an interlaced format to a non-interlaced format. With the goal.

(Means for Solving the Problems) A superimposing device of the present invention that achieves the above object is a non-interlaced type having a horizontal scanning frequency twice the standard horizontal scanning frequency based on an interlaced standard television signal. In a television receiver that generates internal primary color video signals, an external primary color video signal with a standard horizontal scanning frequency and a primary color video signal switching control signal are used as an external primary color video signal and a primary color video signal with a horizontal scanning frequency twice the standard horizontal scanning frequency, respectively. double speed converting means for converting into a signal switching control signal; primary color video signal switching for switching between a non-interlaced internal primary color video signal and a double speed converted external primary color video signal in response to the double speed converted primary color video signal switching control signal; It is characterized by comprising means.

(Operation) Since the internal primary color video signal and the external primary color video signal, each having a standard horizontal scanning frequency, are synchronized with respect to the former, superimposition can be performed in the usual manner.

However, with respect to a non-interlaced internal primary color video signal having a horizontal scanning frequency twice the standard horizontal scanning frequency, total thermal synchronization cannot be achieved with the external primary color video signal as it is, and superimposition cannot be performed.

According to the present invention, by converting the external primary color video signal to double speed, the relative phase relationship with respect to the non-interlaced internal primary color video signal becomes the same as usual. In other words, it becomes a synchronized relationship. Furthermore, the primary color video signal switching control signal accompanying the external primary color video signal is also double-speed converted, so that the relative switching timing between the two primary color video signals is the same as usual, and as a result, the superimposition between the two primary color video signals is Imposition becomes possible.

(Example) The present invention will be described in detail below with reference to FIGS. 1 to 8.

FIG. 1 shows the main structure of a television receiver incorporating a superimposing device according to a first embodiment of the present invention.

NTSC television signal S input to input terminal 10 NTSC is analog-digital (A/D)
The signal is supplied to the converter 12 and is also sent to a teletext receiver (not shown) via the video output terminal 38 of the 21-bin multi-connector 37.

A digital television signal D S NTSC obtained at the output terminal of the A/D converter 12 is supplied to a television video signal processing section 14 including an NTSC decoder, a scan converter, and the like. The scan conversion in the television video signal processing unit 14 is performed according to IDTV by performing line-to-line signal interpolation to convert an interlaced television signal having a horizontal scanning frequency of 15.75 kHz into a non-interlace television signal having a horizontal scanning frequency of 31.5 kHz. This converts it into a standard television signal. Various methods are known for interpolating signals between lines, such as pre-field interpolation, which interpolates with the corresponding scanning line of the previous field, and intra-field interpolation, which interpolates with the upper and lower scanning lines in the same field. Either method may be used. Adding the interpolated scanning lines in this way doubles the number of scanning lines per field to 525, so if you then double the horizontal scanning frequency to 31.5kHz by double speed conversion, you will be able to use non-interlaced television. A gitane signal is obtained.

FIG. 2 shows the configuration of a double speed converter included in the television video signal processing section 14. Input terminal 74.76 has 15.7
A digital interlace signal DSA and interpolation signal DSEI having a horizontal scanning frequency of 5 kHz are input. These signals DSA and DSB are, for example, 14.3M
Each is written to a line memory 78,80 consisting of a FIFO (first in, first out) memory at a write rate of Hz.

On the other hand, from the output terminals of both line memories 78 and 80,
．． Data DSA' and DSB' are read out alternately for each line (horizontal scanning line) at a readout speed of 6 MHz, and in synchronization with this, the switching circuit (e.g., multiplexer) 82 alternately switches to the terminals 82A and 82B. As a result, a digital non-interlaced signal DSAB having a horizontal scanning frequency of 31.5 kHz is obtained at the output terminal 84. Note that the interlace signal DSA, interpolation signal DSB, and non-interlace signal DSAB in this case are at the stage of the luminance signal Y11 signal C.

Referring again to FIG. 1, the television video signal processing section 14 has R.
A GB matrix is included, and by passing the non-interlaced signal DSAB as described above through this,
Non-interlaced internal primary color video signals DRI'', DGI', DBI' with a horizontal scanning frequency of 31.5 kHz
is generated. And these signals DR1', DG+'
, DB++ are output from the television video signal processing section 14,
The input terminals 2OA, 22A of the switching circuit (e.g. multiplexer) 18 through the digital 1/2 attenuator 16.
, 24A, respectively.

On the other hand, the red input terminal 40 of the 21-pin multi-connector 37.
Green input terminal 42. The blue input terminal 44 receives an external primary color red signal Ro + green signal G o + blue signal Bo having a horizontal scanning frequency of 15.75 kHz from the teletext receiver, respectively. These external primary color video signals Ro, Go, B
o are digital signals D Ro and D Go from A/D converters 50, 52, and 54, respectively.

After being converted to DBo, it is supplied to a double speed converter 58.58°60.

FIG. 3 shows the configuration of the double speed converter 56. As expected, FI
A pair of line memories 92,94 consisting of FO memories are used, into which an external primary color red signal DRo is simultaneously written at a writing speed of, for example, 14.3 MHz.

And the writing speed is twice as fast as the writing speed (28.6MHz)
data DRo', alternately for each line (horizontal scanning line)
DRo' is read out, and in synchronization with it, the switching circuit (
For example, multiplexer) 96 alternately switches between terminals 96A and 98B, so that an external primary color red signal DRo" having a horizontal scanning frequency of 31.5 kHz, which is double-speed converted, is obtained at output terminal 98. Double-speed converter 58. 80 may also have the same configuration and operate in the same manner.

Referring again to FIG. 1, the double-speed digital external primary color video signals DRo', DGo", and DBo' obtained at the output terminals of the double-speed converters 5B and 58.80, respectively, are applied to the input terminals 20B, 22B, and 24B of the switching circuit 18. each is given.

In addition, the YM input terminal 48 of the 21-pin multi-connector 37
．． The YS input terminal 48 is connected to the teletext receiving device.
．． Brightness control signal YM with horizontal scanning frequency of 75KHz
, and a primary color video signal switching control signal YS are respectively input. These signals YM and YS are set to TTL level "1" or "0" by comparators 82 and 84, respectively.
” and then supplied to the double-speed converter 88.70. Note that if both signals YM, YS, h!T, and L are input at the L level, the comparators 62 and 64 can be omitted.The double-speed converter 68 .70 is the above double speed converter 56-6
It can be the same as 0, both signals YM and YS are 31.5kHz.
Double speed conversion is performed into signals YM' and YS' having a horizontal scanning frequency of 2. The double-speed brightness control signal YM” obtained in this way
, the primary color video signal switching control signal YS' is 1/2, respectively.
It is supplied to the control terminal of the attenuator 16 and the control terminal of the switching circuit 18. Therefore, the double-speed brightness control signal YM' is "1"
When
Attenuation processing is applied to B1'. Further, when the double-speed primary color video signal switching control signal YS' is "1", the switching circuit 18 switches to the input terminals 20B to 24B and transfers the double-speed digital external primary color video signals DRo'+DGo', DBo' to the subsequent digital - Send to analog (D/A) converters 26-30.

The effect of superimposition according to this embodiment will be explained with reference to FIG. First, an interlaced television video signal (fourth
Figure A) is 31.5K by the TV video signal processing unit 14.
The signal is converted into a non-interlaced television video signal (FIG. 4E) having a horizontal scanning frequency of Hz. On the other hand, the character screen signals (Ro, Go, Bo) with a horizontal scanning frequency of 15.75 kHz given by the teletext receiver (
Figure 4B), primary color video signal switching control signal Ys (Figure 4C
), the brightness control signal YM (FIG. 4D) is sent to the double speed converter 56.
~70, each has a horizontal scanning frequency of 31.5kHz, a double-speed character screen signal (FIG. 4F), a primary color video signal switching control signal Ys'' (FIG. 4G), and a brightness control signal YM.
' (Figure 4H). Therefore, the character screen signal and recontrol signal YS, Y for the television video signal
The phase relationship of M remains the same before and after scanning conversion at 1x speed conversion,
Superimposition becomes possible (4th drawing).

Note that the TV video signals and single character picture electric signals shown as analog signal waveforms in FIGS. 4(E) and 4(F) are digital signals (DRI' and DGI', respectively) in FIG.

DBI'), (DRo', DGo', DBo'). The superimposed waveform in FIG. 4(1) is a digital signal at the output terminal of the switching circuit 18, but the superimposed waveform at the output terminal of the D/A converter 28. ．． The output terminals 32, 34, and 38 after 28.30 have analog waveforms as shown in the figure.

Fig. 5 shows the main configuration of a television receiver incorporating the superimposing device according to the second embodiment. In the figure, components similar to those in FIG. 1 are given the same reference numerals.

This second embodiment is different from the primary color video signal switching control signal YS and brightness control signal YM used in the first embodiment described above.
This is intended to omit the double speed converter 88 and 70.

In order to realize this abbreviation, external primary color video signals Ro, G
o, 2 of double speed converter 56.58.60 for Bo
For example, 58 and 60 also serve as double speed conversion of the recontrol signals YS and YM, as will be explained below.

First, the primary color video signals Go and Bo inputted to the terminals 42 and 44, respectively, are converted into digital signals DGo and DBo by the A/D converters 52 and 54, and then sent to the limiter 100.
102. These limiters too, 102
is the minimum value digital signal (for example, if it is 8 bits, r o , o , o , o , o , o , o , etc.).

), it is converted into a digital signal rO, 0, 0, 0, 0, 0, 0, I J that is one step larger than the minimum value.
It works to replace and output the data, and for input data with other values, it works to output the value as is.

Therefore, '0'' data ro, o, o, o, o, o.

The output signals DGo and DBo of the limiters 100 and 102 that do not contain "0.0" are input terminals 106A of the switching circuits (for example, multiplexers) toe and tos.

108A respectively. It should be noted that, as can be understood, the values of the digital signals DGo and DBo are "Q, 0.0
,0,0,0,0. ro, o which is one step bigger than OJ
.

0.0,0,0,0. Even if it is changed to IJ, the error is extremely small and does not pose a substantial problem.

Input terminals 106B, 1 of these switching circuits toe, tos
08B is given "0" data rO, 0, 0, 0, 0, 0, 0, OJ from the "0" data generation circuit 104.

The switching circuit 108 is controlled by the primary color video signal switching control signal No. 9 YS converted to TTL level, and when YS is “1”
When YS is "0", the input terminal is switched to the input terminal 108A, and when YS is "0", the input terminal is switched to the input terminal 108B.

Therefore, when YS is "1", the digitized external primary color blue signal DBo passes through the switching circuit 108 and is supplied to the double speed converter 80, and when YS is "0", '0''0' from data generation circuit 104
Data rO, 0, 0, 0, 0, 0, 0, OJ are supplied to the double speed converter 60. In this way, the signal YS is multiplexed onto the signal DSo.

On the other hand, the switching circuit 106 receives the primary color video signal switching control signal Y
It is controlled by the logical sum signal (YS+YM) of S and the brightness control signal YM, and when (YS+YM) is "1", it is switched to the input terminal 106A, and when (Ys+YM) is "O", it is switched to the input terminal 106B. ing. Therefore, when (YS+YM) is "1", the digitized external primary color green signal DGo passes through the switching circuit 106 and is supplied to the double speed converter 58, and (YS+YM) is "0".
”, “O” data ro, o from the “0” data generation circuit 104.

Q, 0.0.0.0, and OJ are supplied to the double speed converter 58.

This means that the signal (YS+YM), that is, normally the signal YM, is multiplexed on the signal DBo. In this way, the reason why the switching circuit 106 is not controlled by the control signal YM alone but by the logical sum of both control signals YS and YN is that YM is "0".
This is because YS may become "1" even when .

Therefore, in the double speed converters 58 and 60, not only the digitized external primary color green signal DGo and external primary color blue signal DBo, but also both control signals YS and YM are converted at double speed in the form of "O" data. become. Double speed digital signal [DGo”: +, [D
Bo'co is given to the input terminals 22B and 24B of the switching circuit 18, respectively, and the '0' data detector 11
2.114 respectively.

These “0” data detectors 112, 114 generate an output signal of “0” when the input signal is “0” data rO, 0, 0, 0, 0, 0, 0, OJ, and otherwise generate an output signal of “0”. is “1”
It is designed to generate an output signal.

Therefore, the double-speed digital signal [DBo'
``When there is no data, that is, when the double-speed primary color video signal switching control signal YS is ``1,'' data detector 1
Since the output signal of 14 becomes "L", the switching circuit 18 has input terminals 20B and 22B.

24B, and as a result, the double-speed digital external primary color video signals DRo', DGo'', and DBo' are converted to D/A.
Sent to converter 2B, 28.30. When the double-speed digital signal [DBo] is “0” data, that is, the double-speed primary color video signal switching control signal YS′ is “
O”, the output signal of the data detector 114 is “0”.
0'', the switching circuit 18 switches the input terminals 2OA and 22
A, 24A, and as a result, non-interlaced digital internal primary color video signals DR+', DGt', D
R+' is sent to D/A converter 2B, 28.30. Also, when there is no “0” data in the double-speed digital signal [DGo'], that is, the double-speed brightness control signal YM' is “
1”, the output signal of the data detector 112 is “0”.
1'', the I/2 attenuator 16 operates to halve the values of the internal primary color video signals DRI', DGI'', and DR1'.
This reduces the brightness of the television broadcast image by half.

Next, the operation of this embodiment will be explained with reference to FIG. First, the character screen signal (Bo) as shown in FIG. 6(B) is
After being converted into a digital signal, when it passes through the limiter 102 and the switching circuit 108, the primary color video signal switching control signal YS (FIG. 6C) is superimposed as shown in FIG. 6(E).

In the section where the signal YS is "0", "0" data is inserted. Further, after the character screen signal (Go) is converted into a digital signal, the limiter 100 and the switching circuit 106
As shown in FIG. 6(F), the brightness control signal YM
(FIG. 6D) is superimposed. In the section where the signal YM is "0", "0" data is inserted. When these YM and YS superimposed character screen signals G o and B o are converted to double speed by the speed doubler 58 and 60, respectively, as shown in Fig. 6 (G).
, signals as shown in (■) are obtained. Then, based on these double speed/superimposed character screen signals, the "O" data detectors 114 and 112 operate as shown in FIG. 6(1).

As shown in (J), the control signals YS” and YM are doubled in speed.
” to be restored.

As can be understood, the old signals in FIGS. 6(E) to (E) are in the form of digital signals in FIG.

As described above, in this embodiment, the double speed converter 58.60
There is an advantage that the number of double speed converters can be reduced by being used for double speed conversion of the external primary color video signal and double speed conversion of the control signals YM and YS.

Support 12 FIG. 7 shows the configuration of the third embodiment. This example is
In this embodiment, the switching of the same thick color video signal and the attenuation of the internal primary color video signal in the second embodiment described above are performed in an analog manner.

For this purpose, an analog type 1/2 attenuator 120° switching circuit 122 is provided, and D/A converters 26, 2
8.30 Rikitsu 72 is moved to the front stage of the attenuator 120, and the D/A is connected between the double speed converter 58, 58, 60 and the switching circuit 122.
Transducers 130, 132 and 134 are provided, respectively.

Jitsu JL Den" 1 FIG. 8 shows the main configuration of a television receiver incorporating the superimpose device according to the fourth embodiment.

This example is the second example. This embodiment aims to further reduce the number of speed converters and other elements than the third embodiment.

In FIG. 8, a Y/C separation/interpolation circuit 152, a digital 1/2 attenuator 154, and a double speed converter 162.184
, RGB matrix circuit 166 constitute the television video signal processing section 150.

In this embodiment, the digital television video signal (luminance signal DY, color signal DC) before double speed conversion is transmitted to the 1/2 attenuator 154.
passes through the input terminals 158A and 1BOA of the switching circuit 156.
given to. At this stage, the digital television video signals DY, DC and the digital external primary color video signals DRo, DG
o, DBo and control signals YS, YM are each 15
．． They have a horizontal scanning frequency of 75kHz and are synchronized with each other. During superimposition, the 1/2 attenuator 154 operates in response to the brightness control signal YM, and the switching circuit 156 operates at the input terminals 158A, 180A or 158B, 180B in response to the primary color video signal switching control signal YS.
By selectively switching to the digital television video signals DY', DC' and the digital external primary color video signal DR.
o, DGo, and DBo, for example, D Ro, D
Go is multiplexed. At this time, the switching circuit 158
When switching between 58B and 180B, the TV video signal will be missing, but since that portion is a superimposed section, it is not necessary in the first place. What is needed at that time is an external primary color video signal to be inserted by superimposition, which is the input terminal 158B, 1
60B.

Thus, the double speed converters 182 and 164 convert the digital television video signals DY and DC and the digital external primary color video signals D Ro and DG multiplexed thereto.

The output terminals of these double speed converters 162 and 1434 receive a non-interlaced digital television video signal DY'.

DC'' and a double-speed digital external primary color video signal DRo''=DGo' multiplexed thereto are obtained in a time-division manner.

On the other hand, the remaining one of the external primary color video signals Bo is the second one. Similar to the third embodiment, the A/D converter 54° limiter 102
．． The switching circuit 1089 passes through the double speed converter 60. As a result, the double-speed digital external primary color signal [DBo'] superimposed with the control signal YS is obtained at the output terminal of the double-speed converter 60, and the restored double-speed digital primary color signal [DBo'] is provided at the output terminal of the "0" data detector 114. A control signal YS' is obtained.

Therefore, when "YS" is "0", the switching circuit 18 switches to the input terminals 20A to 24A, and the RGB matrix 1
66, non-interlaced digital internal primary color video signals DR+', DGi'', DBI' are sent to the D/A converter 26.
Sent to ~30. When YS' is "1", the double-speed digital external primary color video signals DRO°, DGo', and DBo' from the double-speed converter IEi2.16460 are D/
The signals are sent to A converters 26-30.

As described above, in this embodiment, the number of parts such as a double-speed converter is reduced, but as in the first to third embodiments, the external primary color video signal is superimposed on the non-interlaced internal primary color video signal. Poses are possible.

In the first to third embodiments as well, the brightness of the television video signal may be halved before double speed conversion as in this embodiment.

, Further, superimposition may be performed without providing the brightness control signal YM, and the present invention is also applicable to such cases. Furthermore, the present invention is applicable not only to a connected adapter-type teletext receiver, but also to a television receiver connected to a built-in character decoder, an independent adapter, etc. It is also applicable when obtained from a personal computer or the like.

(Effects of the Invention) As described above, according to the present invention, even if a television signal is converted from an interlace system to a non-interlace system, it is possible to superimpose an external primary color video signal thereon.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the main structure of a television receiver incorporating a superimposing device according to a first embodiment of the present invention, and FIG. A block diagram showing the configuration of the double speed converter shown in FIG.
FIG. 4 is a block diagram showing the configuration of the double speed converter 56 for the external primary color video signal; FIG. 4 is a signal waveform diagram for explaining the superimposition effect according to the first embodiment;
6 is a block diagram showing the main configuration of a television receiver incorporating a superimposing device according to the second embodiment; FIG. 6 is a signal waveform diagram for explaining the operation of the second embodiment; FIG. 7 is a block diagram showing the main configuration of a television receiver incorporating the superimposing device according to the third embodiment, and FIG. 8 is a block diagram showing the main configuration of a television receiver incorporating the superimposing device according to the fourth embodiment. FIG. 9 is a block diagram showing the main components of a conventional television receiver connected to a teletext receiving device. FIG. 10 is a block diagram showing the main components of a conventional television receiver connected to a teletext receiver. FIG. 3 is a signal waveform diagram for explaining the effect of superimposition in FIG. 12...A/D converter, 14...TV video signal processing unit (NTSC decoder, operation converter), 16...1/2 attenuator, 18...changeover switch , 26-30...D/A converter, 37...21-pin multi-connector, 40-44...
...External video signal input terminal, 46...Brightness control signal input terminal, 48...Video signal switching control signal, 50-54...A/D converter, 56-60... Double speed converter, 68.70... Double speed converter, 100.102... Limiter, 108.108... Changeover switch, 112.114
... "0" data detector, 120 ... l/2 attenuator, 122 ... changeover switch, 150 ... TV video signal processing section, 152 ...
Y/C separation/interpolation circuit, 154...l/2 attenuator, 156...changeover switch, 182.184...double speed converter.

Claims (1)

[Claims] In a television receiver that generates a non-interlaced internal primary color video signal having a horizontal scanning frequency twice the standard horizontal scanning frequency based on an interlaced standard television signal, the standard horizontal scanning frequency is double speed conversion means for converting an external primary color video signal and a primary color video signal switching control signal having a horizontal scanning frequency twice the standard horizontal scanning frequency into an external primary color video signal and a primary color video signal switching control signal, respectively; primary color video signal switching means for switching between the non-interlaced internal primary color video signal and the double speed converted external primary color video signal in response to a primary color video signal switching control signal. Pause device.