JPS61163778A - Two-picture television receiver - Google Patents

Abstract

PURPOSE:To reduce an omission of information by incorporating the information of a three horizontal scanning line portion of an original picture of a slave picture, by constituting a title television receiver so that a luminance signal of a one horizontal scanning period portion of the slave picture is obtained by weighting and adding a luminance signal of three horizontal scanning periods. CONSTITUTION:A title television receiver is provided with an N-stage shift register 10 for storing temporarily a data which has sampled a luminance signal converted to a digital signal by an A/D converter 2, N times in one horizontal scanning period, a sampling data of an original picture horizontal scanning period of the (3n-2)-th slave picture (n is a slave picture horizontal scanning line number) is stored in a register 10 in order of sampling, and subsequently, a data which has multiplied by 2 a sampling data of an original picture horizontal scanning period of the (3n-1)-th slave picture, and the data stored in the shift register 10 are added by an adding circuit 8 in order of sampling and stored in the register 10, and subsequently, a sam pling data of an original picture horizontal scanning period of the 3n-th slave picture, and the data stored in the register 10 are added by the adding circuit 8, and the added data is multiplied by 1/4 and the level is matched, and it becomes a luminance signal of the slave picture.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention provides a method for displaying images of other channels and VTRs on a part of the main screen.
Background of the Invention In recent years, in order to make effective use of television receivers, in order to make effective use of television receivers,
2. Description of the Related Art So-called two-screen television receivers are on the market, which display a reduced-sized fine image as part of the original television image. (
Nikkei Electronics April 14, 1980 67th ~
(page 62, etc.)

The concept of the video signal sampling method for displaying this small screen will be briefly described below with reference to FIGS. 3 and 4. FIG. 3 is a circuit diagram of the video signal sampling circuit, and FIG. 4 is a timing chart of each part in FIG. 3.

To reduce the size of the child screen to 1/3 of the original screen in the vertical direction, select one out of three horizontal scanning lines and use this as the horizontal scanning line of the child screen. In FIG. 3, a control signal 28 is generated from the horizontal synchronizing signal 30 through a divide-by-3 circuit 29 to be at a high level only during the horizontal scanning period of one of the three horizontal scanning lines (here, the period to FIG. 4). , the gate circuit 26 outputs the clock 27 only during the period when the control signal 28 is at a high level as the sampling clock 24, and the input signal 22 is sampled by the A/D converter 23 to generate digital data 25.
(25a-26e) are obtained.

Problems to be Solved by the Invention However, in this method, one of the three horizontal scanning lines is selected and this is set as the horizontal scanning line of the sub-screen, and the information for the horizontal scanning line is lost. In the two-screen television receiver of the present invention, the luminance signals for one horizontal scanning period of the child screen are obtained by weighting and adding the luminance signals for three horizontal scanning periods.
The information of three horizontal scanning lines of the original screen of the child screen is included to reduce the loss of information.

Function: In the two-screen television receiver of the present invention, the luminance signals of three horizontal scanning periods are weighted in the order of the scanning lines,
The sampling data of the first horizontal scanning period among the three is stored in the storage element in the sampling order, and the sampling data of the second horizontal scanning period and the data stored in the storage element are sequentially added and stored again. The addition result is stored in the element, the glyph data of the third horizontal scanning period is added to the data stored in the storage element, and the addition result is returned to the original amplitude level to reproduce the original screen. Match the brightness signal level/prefume level.

Embodiment Hereinafter, a two-screen television receiver according to an embodiment of the present invention will be described with reference to the drawings. , FIG. 1 is a circuit diagram of a luminance signal sampling circuit portion of the present invention, and FIG. 2 is a timing chart of each part in FIG. 1.

In FIG. 1, the horizontal synchronization signal 21 is frequency-divided by a 3-frequency divider circuit 2o, the selector control signal 16 is at a high level during the (3n-2) horizontal scanning period, and the bit shift control signal is controlled during the (3n-1) horizontal scanning period. Three-phase control signals are obtained in which the signal 6 is at a high level and the data output control signal 18 is at a high level during the (3n) horizontal scanning period. (Here, n indicates the sub-screen horizontal scanning line number.) These control signals are sent to each selector circuit 14. Bit shift circuit 6. Data output gate 1
70 control signal.

A luminance input signal 1 is converted into digital data 4a to 4e by an A/D converter 2 using a sampling clock 3.

(3n-2) During the horizontal scanning period, the bit shift control signal 6 is at a low level, and the data output cuffs b to 7f (7a is at a low level) of the bit shift circuit 6 are input to the adder circuit 8. Added. At this time, selector control signal 16
is at a high level, and the selector circuit 140B side input signal 1
3a to 13q (low level) become output signals 16a to 16g of the selector circuit 14 and are added to B inputs of the adder circuit 8, and the addition results are stored in the eight-stage shift register 10 at the timing of the shift clock 11.

Next, during the (3n-1) horizontal scanning period, the bit shift control signal 6 is at a high level, and the digital data 4a
.about.4e are shifted upward by one pit, and data output signals 7a to 7.multidot.(7f is low level) of the bit shift circuit 6 are applied to the input side of the adder circuit 8. During this time, the selector control signal 16 is at a low level, and in the selector circuit 14, the output signals 12a to 12g of the N-stage shift register 1o are
is selected and added as the B input signal 13 of the adder circuit 8, and the addition result is stored in the eight-stage shift register 10 again.

Furthermore, in the (3n) horizontal scanning period, the bit shift control signal 6 becomes low level and the selector control signal 16 also becomes low level, so the output signal 7b of the bit shift circuit 6
~yf (7a is a low level) is added to the input side of the adder circuit 8, and the output signal 12a~ of the 8-stage shift register 10
12(i is added to the B input side of the adder circuit 8 and added.

Further, the data output control signal 18 becomes high level only during this (3n) horizontal scanning period, and the addition result is output from the data output gate 17.

In this way, since the sampling data of three horizontal scanning line periods are added with a weighting ratio of 1:2:1, the addition result is digitally amplified by 4 times the luminance signal human power 1, and in this embodiment, the amplification is 6 times. Bit sampling data becomes 7 bits.

Therefore, the data output gate 17 extracts the higher six bits as data output signals 19a to 19e and outputs the addition result as 1.
/I try to match the level by multiplying by 4. In addition, N
The number of stages of the stage shift register 1o is the same as the number of samplings in one horizontal scanning period, which is eight.

Effects of the Invention As described above, according to the two-screen television receiver of the present invention, by correlating the luminance signals of three horizontal scanning periods, the original screen of the sub-screen can be /3
Even if it is reduced, the loss of brightness information can be reduced, which is extremely advantageous in practice for improving the image quality of the sub-screen.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of the main parts of a two-screen television receiver according to an embodiment of the present invention, Fig. 2 is a timing chart of each part thereof, Fig. 3 is a circuit diagram of a conventional video signal sampling circuit, and Fig. 4 is a circuit diagram of a conventional video signal sampling circuit. The figure is a timing chart of each part. 1...Brightness input signal, 2...-A/D transformer, 3...Sampling clock, 4...
- Digital data, 5... Pit shift circuit, 6... Bit shift control signal, 7...
...Data output signal of pit shift circuit, 8...
・Addition circuit, 9... Addition output signal, 1o...
...Shift register, 11...Shift clock, 12...Output signal of shift register, 13
...B input signals of the selector circuit, 14...
...-Selector circuit, 16...Selector control signal, 16...Selector closing output signal, 17.
......-data output gate, 18...data output control signal, 19...data output signal, 20
...3 frequency divider circuit, 21 ... horizontal synchronization signal. Name of agent: Patent attorney Toshio Nakao and 1 other person26
...Ri'-to story^Route 2q--3rd tail port Q

Claims (2)

[Claims] (1) By weighting and adding the luminance signals of the 3 horizontal scanning periods of the television signal to be displayed on the sub screen to the luminance signals of each of the first, second, and third horizontal scanning periods, A two-screen television receiver characterized in that a luminance signal is obtained by correlating luminance signals during a scanning period, and a sub-screen is displayed using the luminance signal as a result of the addition. (2) storage means for temporarily storing sampling data obtained by sampling the luminance signal converted into a digital signal by the A/D converter N times in one horizontal scanning period;
means for storing sampling data of the original screen horizontal scanning period of the (n is the child screen horizontal scanning line number)-th child screen in the storage means in the sampling order, and the original screen horizontal scanning period of the (3n-1)th child screen; means for doubling the sampling data of the 3nth child screen; means for adding the doubled data and the data stored in the storage means in the sampling order and storing the data in the storage means; The data includes means for adding the sampling data of the scanning period and the data stored in the storage means and multiplying the added data by 1/4, and correlating the three horizontal scanning periods of the original screen of the child screen. A two-screen television receiver according to claim 1, characterized in that the luminance signal of the sub-screen is reduced.